Death domain containing receptor 5

[0001] The present application claims benefit to the filing dates of U.S. Provisional Application No. 60/148,939, filed Aug. 13, 1999, U.S. Provisional Application No. 60/133,238, filed May 7, 1999, U.S. Provisional Application No. 60/132,498, filed May 4, 1999, and is a continuation-in-part of U.S. application Ser. No. 09/042,583, filed Mar. 17, 1998, each of which is herein incorporated by reference; said Ser. No. 09/042,583 claims priority to U.S. Provisional Application No. 60/054,021, filed Jul. 29, 1997, and U.S. Provisional Application No. 60/040,846, filed Mar. 17, 1997, each of which is herein incorporated by reference.

[0002] 1. Field of the Invention

[0003] The present invention relates to a novel member of the tumor necrosis factor family of receptors. More specifically, isolated nucleic acid molecules are provided encoding human Death Domain Containing Receptor 5, or simply DR5. DR5 polypeptides are also provided, as are vectors, host cells, and recombinant methods for producing the same. The invention further relates to screening methods for identifying agonists and antagonists of DR5 activity.

[0004] 2. Related Art

[0005] Numerous biological actions, for instance, response to certain stimuli and natural biological processes, are controlled by factors, such as cytokines. Many cytokines act through receptors by engaging the receptor and producing an intra-cellular response.

[0006] For example, tumor necrosis factors (TNF) alpha and beta are cytokines, which act through TNF receptors to regulate numerous biological processes, including protection against infection and induction of shock and inflammatory disease. The TNF molecules belong to the TNF-ligand superfamily, and act together with their receptors or counter-ligands, the TNF-receptor superfamily. So far, nine members of the TNF ligand superfamily have been identified and ten members of the TNF-receptor superfamily have been characterized.

[0007] Among the ligands, there are included TNF-, lymphotoxin- (LT-, also known as TNF-), LT- (found in complex heterotrimer LT-2-), FasL, CD40L, CD27L, CD30L, 4-1BBL, OX40L and nerve growth factor (NGF). The superfamily of TNF receptors includes the p55TNF receptor, p75TNF receptor, TNF receptor-related protein, FAS antigen or APO-1, CD40, CD27, CD30, 4-1BB, OX40, low affinity p75 and NGF-receptor (Meager, A., Biologicals, 22:291-295 (1994)).

[0008] Many members of the TNF-ligand superfamily are expressed by activated T-cells, implying that they are necessary for T-cell interactions with other cell types which underlie cell ontogeny and functions. (Meager, A., supra).

[0009] Considerable insight into the essential functions of several members of the TNF receptor family has been gained from the identification and creation of mutants that abolish the expression of these proteins. For example, naturally occurring mutations in the FAS antigen and its ligand cause lymphoproliferative disease (Watanabe-Fukunaga, R., et al., Nature 356:314 (1992)), perhaps reflecting a failure of programmed cell death. Mutations of the CD40 ligand cause an X-linked immunodeficiency state characterized by high levels of immunoglobulin M and low levels of immunoglobulin G in plasma, indicating faulty T-cell-dependent B-cell activation (Allen, R. C. et al., Science 259:990 (1993)). Targeted mutations of the low affinity nerve growth factor receptor cause a disorder characterized by faulty sensory innovation of peripheral structures (Lee, K. F. et al., Cell 69:737 (1992)).

[0010] TNF and LT- are capable of binding to two TNF receptors (the 55- and 75-kd TNF receptors). A large number of biological effects elicited by TNF and LT-, acting through their receptors, include hemorrhagic necrosis of transplanted tumors, cytotoxicity, a role in endotoxic shock, inflammation, immunoregulation, proliferation and anti-viral responses, as well as protection against the deleterious effects of ionizing radiation. TNF and LT- are involved in the pathogenesis of a wide range of diseases, including endotoxic shock, cerebral malaria, tumors, autoimmune disease, AIDS and graft-host rejection (Beutler, B. and Von Huffel, C., Science 264:667-668 (1994)). Mutations in the p55 Receptor cause increased susceptibility to microbial infection.

[0011] Moreover, an about 80 amino acid domain near the C-terminus of TNFR-1 (p55) and Fas was reported as the death domain, which is responsible for transducing signals for programmed cell death (Tartaglia et al., Cell 74:845 (1993)).

[0012] Apoptosis, or programmed cell death, is a physiologic process essential for the normal development and homeostasis of multicellular organisms (H. Steller, Science 267:1445-1449 (1995)). Derangements of apoptosis contribute to the pathogenesis of several human diseases including cancer, neurodegenerative disorders, and acquired immune deficiency syndrome (C. B. Thompson, Science 267:1456-1462 (1995)). Recently, much attention has focused on the signal transduction and biological function of two cell surface death receptors, Fas/APO-1 and TNFR-1 (J. L. Cleveland et al., Cell 81:479-482 (1995); A. Fraser, et al., Cell 85:781-784 (1996); S. Nagata et al., Science 267:1449-56 (1995)). Both are members of the TNF receptor family which also include TNFR-2, low affinity NGFR, CD40, and CD30, among others (C. A. Smith et al., Science 248:1019-23 (1990); M. Tewari et al., in Modular Texts in Molecular and Cell Biology M. Purton, Heldin, Carl, Ed. (Chapman and Hall, London, 1995). While family members are defined by the presence of cysteine-rich repeats in their extracellular domains, Fas/APO-1 and TNFR-1 also share a region of intracellular homology, appropriately designated the death domain, which is distantly related to the Drosophila suicide gene, reaper (P. Golstein, et al., Cell 81:185-186 (1995); K. White et al., Science 264:677-83 (1994)). This shared death domain suggests that both receptors interact with a related set of signal transducing molecules that, until recently, remained unidentified. Activation of Fas/APO-1 recruits the death domain-containing adapter molecule FADD/MORT1 (A.M. Chinnaiyan et al., Cell 81: 505-12 (1995); M. P. Boldin et al., J. Biol Chem 270:7795-8 (1995); F. C. Kischkel et al., EMBO 14:5579-5588 (1995)), which in turn binds and presumably activates FLICE/MACH1, a member of the ICE/CED-3 family of pro-apoptotic proteases (M. Muzio et al., Cell 85:817-827 (1996); M. P. Boldin et al., Cell 85:803-815 (1996)). While the central role of Fas/APO-1 is to trigger cell death, TNFR-1 can signal an array of diverse biological activities-many of which stem from its ability to activate NF-kB (L. A. Tartaglia et al., Immunol Today 13:151-3 (1992)). Accordingly, TNFR-1 recruits the multivalent adapter molecule TRADD, which like FADD, also contains a death domain (H. Hsu et al., Cell 81:495-504 (1995); H. Hsu, et al., Cell 84:299-308 (1996)). Through its associations with a number of signaling molecules including FADD, TRAF2, and RIP, TRADD can signal both apoptosis and NF-kB activation (H. Hsu et al., Cell 84:299-308 (1996); H. Hsu, et al., Immunity 4:387-396 (1996)).

[0013] Recently, a new apoptosis-inducing TNF ligand has been discovered. S. R. Wiley et al. (Immunity 3:673-682 (1995)) named the moleculeTNF-related apoptosis-inducing ligand or simply TRAIL. The molecule was also called Apo-2 ligand or Apo-2L. R. M. Pitt et al., J. Biol. Chem. 271:12687-12690 (1996). For convenience, the molecule will be referred to herein as TRAIL.

[0014] Unlike FAS ligand, whose transcripts appear to be largely restricted to stimulated T-cells, significant levels of TRAIL are detected in many human tissues (e.g., spleen, lung, prostate, thymus, ovary, small intestine, colon, peripheral blood lymphocytes, placenta, kidney), and is constitutively transcribed by some cell lines. It has been shown that TRAIL acts independently from the Fas ligand (Wiley et al., supra). It has also been shown that TRAIL activates apoptosis rapidly, within a time frame that is similar to death signaling by Fas/Apo-1L, but much faster than TNF-induced apoptosis. S. A. Marsters et al., Current Biology 6:750-752 (1996). The inability of TRAIL to bind TNFR-1, Fas, or the recently identified DR3, suggests that TRAIL may interact with a unique receptor(s).

[0015] The effects of TNF family ligands and TNF family receptors are varied and influence numerous functions, both normal and abnormal, in the biological processes of the mammalian system. There is a clear need, therefore, for identification and characterization of such receptors and ligands that influence biological activity, both normally and in disease states. In particular, there is a need to isolate and characterize additional novel receptors that bind TRAIL.

[0016] The present invention provides for isolated nucleic acid molecules comprising, or alternatively consisting of, nucleic acid sequences encoding the amino acid sequence shown in FIG. 1 (SEQ ID NO:2) or the amino acid sequence encoded by the cDNA deposited as ATCC Deposit No. 97920 on Mar. 7, 1997.

[0017] The present invention also provides recombinant vectors, which include the isolated nucleic acid molecules of the invention, and to host cells containing the recombinant vectors, as well as to methods of making such vectors and host cells and for using them for production of DR5 polypeptides or peptides by recombinant techniques.

[0018] The invention further provides an isolated DR5 polypeptide having an amino acid sequence encoded by a polynucleotide described herein.

[0019] The present invention also provides diagnostic assays such as quantitative and diagnostic assays for detecting levels of DR5 protein. Thus, for instance, a diagnostic assay in accordance with the invention for detecting over-expression of DR5, or soluble form thereof, compared to normal control tissue samples may be used to detect the presence of tumors.

[0020] Tumor Necrosis Factor (TNF) family ligands are known to be among the most pleiotropic cytokines, inducing a large number of cellular responses, including cytotoxicity, anti-viral activity, immunoregulatory activities, and the transcriptional regulation of several genes. Cellular response to TNF-family ligands include not only normal physiological responses, but also diseases associated with increased apoptosis or the inhibition of apoptosis. Apoptosisprogrammed cell deathis a physiological mechanism involved in the deletion of peripheral T lymphocytes of the immune system, and its dysregulation can lead to a number of different pathogenic processes. Diseases associated with increased cell survival, or the inhibition of apoptosis, include cancers, auto immune disorders, viral infections, inflammation, graft versus host disease, acute graft rejection, and chronic graft rejection. Diseases associated with increased apoptosis include AIDS, neurodegenerative disorders, myelodysplastic syndromes, ischemic injury, toxin-induced liver disease, septic shock, cachexia and anorexia.

[0021] Thus, the invention further provides a method for enhancing apoptosis induced by a TNF-family ligand, which involves administering to a cell which expresses the DR5 polypeptide an effective amount of an agonist capable of increasing DR5 mediated signaling. Preferably, DR5 mediated signaling is increased to treat and/or prevent a disease wherein decreased apoptosis is exhibited.

[0022] In a further aspect, the present invention is directed to a method for inhibiting apoptosis induced by a TNF-family ligand, which involves administering to a cell which expresses the DR5 polypeptide an effective amount of an antagonist capable of decreasing DR5 mediated signaling. Preferably, DR5 mediated signaling is decreased to treat and/or prevent a disease wherein increased apoptosis is exhibited.

[0023] Whether any candidate agonist or antagonist of the present invention can enhance or inhibit apoptosis can be determined using art-known TNF-family ligand/receptor cellular response assays, including those described in more detail below. Thus, in a further aspect, a screening method is provided for determining whether a candidate agonist or antagonist is capable of enhancing or inhibiting a cellular response to a TNF-family ligand. The method involves contacting cells which express the DR5 polypeptide with a candidate compound and a TNF-family ligand, assaying a cellular response, and comparing the cellular response to a standard cellular response, the standard being assayed when contact is made with the ligand in absence of the candidate compound, whereby an increased cellular response over the standard indicates that the candidate compound is an agonist of the ligand/receptor signaling pathway and a decreased cellular response compared to the standard indicates that the candidate compound is an antagonist of the ligand/receptor signaling pathway. By the invention, a cell expressing the DR5 polypeptide can be contacted with either an endogenous or exogenously administered TNF-family ligand.

[0024] FIG. 1 shows the nucleotide (SEQ ID NO:1) and deduced amino acid sequence (SEQ ID NO:2) of DR5. It is predicted that amino acids from about 1 to about 51 (underlined) constitute the signal peptide (amino acid residues from about 51 to about 1 in SEQ ID NO:2); amino acids from about 52 to about 184 constitute the extracellular domain (amino acid residues from about 1 to about 133 in SEQ ID NO:2); amino acids from about 84 to about 179 constitute the cysteine rich domain (amino acid residues from about 33 to 128 in SEQ ID NO:2); amino acids from about 185 to about 208 (underlined) constitute the transmembrane domain (amino acid residues from about 134 to about 157 in SEQ ID NO:2); and amino acids from about 209 to about 411 constitute the intracellular domain (amino acid residues from about 158 to about 360 in SEQ ID NO:2), of which amino acids from about 324 to about 391 (italicized) constitute the death domain (amino acid residues from about 273 to about 340 in SEQ ID NO:2).

[0025] FIG. 2 shows the regions of similarity between the amino acid sequences of DR5 (HLYBX88), human tumor necrosis factor receptor 1 (h TNFR-1) (SEQ ID NO:3), human Fas protein (SEQ ID NO:4), and the death domain containing receptor 3 (SEQ ID NO:5). The comparison was created with the Megalign program which is contained in the DNA Star suite of programs, using the Clustal method. Residues that match the consensus are shaded.

[0026] FIG. 3 shows an analysis of the DR5 amino acid sequence. Alpha, beta, turn and coil regions; hydrophilicity and hydrophobicity; amphipathic regions; flexible regions; antigenic index and surface probability are shown, as predicted for the amino acid sequence depicted in FIG. 1 using the default parameters of the recited computer program. In the Antigenic IndexJameson-Wolf graph, amino acid residues about 62 to about 110, about 119 to about 164, about 224 to about 271, and about 275 to about 370 as depicted in FIG. 1 correspond to the shown highly antigenic regions of the DR5 protein. These highly antigenic fragments in FIG. 1 correspond to the following fragments, respectively, in SEQ ID NO:2: amino acid residues from about 11 to about 59, from about 68 to about 113, from about 173 to about 220, and from about 224 to about 319.

[0027] FIG. 4 shows the nucleotide sequences (HAPBU13R and HSBBU76R) of two cDNA molecules which are related to the nucleotide sequence shown in FIG. 1 (SEQ ID NO:1).

[0028] FIG. 5A is a bar graph showing that overexpression of DR5 induced apoptosis in MCF7 human breast carcinoma cells. FIG. 5B is a bar graph showing that overexpression of DR5 induced apoptosis in human epitheloid carcinoma (HeLa) cells. FIG. 5C is a bar graph showing that DR5-induced apoptosis was blocked by caspase inhibitors, CrmA and z-VAD-fmk, but dominant negative FADD was without effect. FIG. 5D is an immunoblot showing that, like DR4, DR5 did not interact with FADD and TRADD in vivo. FIG. 5E is a bar graph showing that a dominant negative version of a newly identified FLICE-like molecule, FLICE2 (Vincenz, C. et al., J Biol. Chem. 272:6578 (1997)), efficiently blocked DR5-induced apoptosis, while dominant negative FLICE had only partial effect under conditions it blocked. It also shows that TNFR-1 blocked apoptosis effectively.

[0029] FIG. 6A is an immunoblot showing that DR5-Fc (as well as DR4 and TRID) specifically bound TRAIL, but not the related cytotoxic ligand TNF. The bottom panel of FIG. 6A shows the input Fc-fusions present in the binding assays. FIG. 6B is a bar graph showing that DR5-Fc blocked the ability of TRAIL to induce apoptosis. The data (meanSD) shown in FIG. 6B are the percentage of apoptotic nuclei among total nuclei counted (n4). FIG. 6C is a bar graph showing that DR5-Fc had no effect on apoptosis TNF-induced cell death under conditions where TNFR-1-Fc completely abolished TNF killing.

[0030] The present invention provides isolated nucleic acid molecules comprising, or alternatively consisting of, a polynucleotide encoding a DR5 polypeptide having the amino acid sequence shown in FIG. 1 (SEQ ID NO:2), or a fragment of this polypeptide. The DR5 polypeptide of the present invention shares sequence homology with other known death domain containing receptors of the TNFR family including human TNFR-1, DR3 and Fas (FIG. 2). The nucleotide sequence shown in FIG. 1 (SEQ ID NO:1) was obtained by sequencing cDNA clones such as HLYBX88, which was deposited on Mar. 7, 1997 at the American Type Culture, 10801 University Boulevard, Manassas, Va. 20110-2209, and given Accession Number 97920. The deposited cDNA is contained in the pSport 1 plasmid (Life Technologies, Gaithersburg, Md.).

[0031] Nucleic Acid Molecules

[0032] Unless otherwise indicated, all nucleotide sequences determined by sequencing a DNA molecule herein were determined using an automated DNA sequencer (such as the Model 373 from Applied Biosystems, Inc.), and all amino acid sequences of polypeptides encoded by DNA molecules determined herein were predicted by translation of a DNA sequence determined as above. Therefore, as is known in the art for any DNA sequence determined by this automated approach, any nucleotide sequence determined herein may contain some errors. Nucleotide sequences determined by automation are typically at least about 90% identical, more typically at least about 95% to at least about 99.9% identical to the actual nucleotide sequence of the sequenced DNA molecule. The actual sequence can be more precisely determined by other approaches including manual DNA sequencing methods well known in the art. As is also known in the art, a single insertion or deletion in a determined nucleotide sequence compared to the actual sequence will cause a frame shift in translation of the nucleotide sequence such that the predicted amino acid sequence encoded by a determined nucleotide sequence will be completely different from the amino acid sequence actually encoded by the sequenced DNA molecule, beginning at the point of such an insertion or deletion.

[0033] Using the information provided herein, such as the nucleic acid sequence set out in SEQ ID NO :1, a nucleic acid molecule of the present invention encoding a DR5 polypeptide may be obtained using standard cloning and screening procedures, such as those for cloning cDNAs using mRNA as starting material. Illustrative of the invention, the nucleic acid molecule of the invention has been identified in cDNA libraries of the following tissues: primary dendritic cells, endothelial tissue, spleen, chronic lymphocytic leukemia, and human thymus stromal cells.

[0034] The determined nucleotide sequence of the DR5 cDNA of SEQ ID NO:1 contains an open reading frame encoding a protein of about 411 amino acid residues whose initiation codon is at position 130-132 of the nucleotide sequence shown in FIG. 1 (SEQ ID NO.1), with a leader sequence of about 51 amino acid residues. Of known members of the TNF receptor family, the DR5 polypeptide of the invention shares the greatest degree of homology with human TNFR-1, FAS and DR3 polypeptides shown in FIG. 2, including significant sequence homology over multiple cysteine-rich domains. The homology DR5 shows to other death domain containing receptors strongly indicates that DR5 is also a death domain containing receptor with the ability to induce apoptosis. DR5 has also now been shown to bind TRAIL.

[0035] As indicated, the present invention also provides the mature form(s) of the DR5 protein of the present invention. According to the signal hypothesis, proteins secreted by mammalian cells have a signal or secretory leader sequence which is cleaved from the mature protein once export of the growing protein chain across the rough endoplasmic reticulum has been initiated. Most mammalian cells and even insect cells cleave secreted proteins with the same specificity. However, in some cases, cleavage of a secreted protein is not entirely uniform, which results in two or more mature species on the protein. Further, it has long been known that the cleavage specificity of a secreted protein is ultimately determined by the primary structure of the complete protein, that is, it is inherent in the amino acid sequence of the polypeptide.

[0036] Therefore, the present invention provides a nucleotide sequence encoding the mature DR5 polypeptide having the amino acid sequence encoded by the cDNA contained in the plasmid identified as ATCC Deposit No. 97920, and as shown in FIG. 1 (SEQ ID NO:2). By the mature DR5 protein having the amino acid sequence encoded by the cDNA contained in the plasmid identified as ATCC Deposit No. 97920, is meant the mature form(s) of the DR5 protein produced by expression in a mammalian cell (e.g., COS cells, as described below) of the complete open reading frame encoded by the human cDNA contained in the deposited plasmid. As indicated below, the mature DR5 having the amino acid sequence encoded by the cDNA contained in ATCC Deposit No. 97920, may or may not differ from the predicted mature DR5 protein shown in SEQ ID NO:2 (amino acids from about 1 to about 360) depending on the accuracy of the predicted cleavage site based on computer analysis.

[0037] Methods for predicting whether a protein has a secretory leader as well as the cleavage point for that leader sequence are available. For instance, the method of McGeoch (Virus Res. 3:271-286 (1985)) and von Heinje (Nucleic Acids Res. 14:4683-4690 (1986)) can be used. The accuracy of predicting the cleavage points of known mammalian secretory proteins for each of these methods is in the range of 75-80%. von Heinje, supra. However, the two methods do not always produce the same predicted cleavage point(s) for a given protein.

[0038] In the present case, the predicted amino acid sequence of the complete DR5 polypeptide of the present invention was analyzed by a computer program (PSORT). See, K. Nakai and M. Kanehisa, Genomics 14:897-911 (1992). PSORT is an expert system for predicting the cellular location of a protein based on the amino acid sequence. As part of this computational prediction of localization, the methods of McGeoch and von Heinje are incorporated. The analysis by the PSORT program predicted the cleavage sites between amino acids 51 and 52 in FIG. 1 (1 and 1 in SEQ ID NO:2). Thereafter, the complete amino acid sequences were further analyzed by visual inspection, applying a simple form of the (1,3) rule of von Heinje von Heinje, supra. Thus, the leader sequence for the DR5 protein is predicted to consist of amino acid residues from about 1 to about 51, underlined in FIG. 1 (corresponding to amino acid residues about 51 to about 1 in SEQ ID NO:2), while the predicted mature DR5 protein consists of residues from about 52 to about 411 in FIG. 1 (corresponding to amino acid residues about 1 to about 360 in SEQ ID NO:2).

[0039] As one of ordinary skill would appreciate, due to the possibility of sequencing errors, as well as the variability of cleavage sites for leaders in different known proteins, the predicted DR5 receptor polypeptide encoded by the deposited cDNA comprises about 411 amino acids, but may be anywhere in the range of 401-421 amino acids; and the predicted leader sequence of this protein is about 51 amino acids, but may be anywhere in the range of about 41 to about 61 amino acids. It will further be appreciated that, the domains described herein have been predicted by computer analysis, and accordingly, that depending on the analytical criteria used for identifying various functional domains, the exact address of, for example, the extracelluar domain, intracellular domain, death domain, cysteine-rich motifs, and transmembrane domain of DR5 may differ slightly. For example, the exact location of the DR5 extracellular domain in FIG. 1 (SEQ ID NO:2) may vary slightly (e.g., the address may shift by about 1 to about 20 residues, more likely about 1 to about 5 residues) depending on the criteria used to define the domain. In any event, as discussed further below, the invention further provides polypeptides having various residues deleted from the N-terminus and/or C-terminus of the complete DR5, including polypeptides lacking one or more amino acids from the N-termini of the extracellular domain described herein, which constitute soluble forms of the extracellular domain of the DR5 polypeptides.

[0040] As indicated, nucleic acid molecules of the present invention may be in the form of RNA, such as mRNA, or in the form of DNA, including, for instance, cDNA and genomic DNA obtained by cloning or produced synthetically. The DNA may be double-stranded or single-stranded. Single-stranded DNA may be the coding strand, also known as the sense strand, or it may be the non-coding strand, also referred to as the anti-sense strand.

[0041] By isolated nucleic acid molecule(s) is intended a nucleic acid molecule, DNA or RNA, which has been removed from its native environment For example, recombinant DNA molecules contained in a vector are considered isolated for the purposes of the present invention. Further examples of isolated DNA molecules include recombinant DNA molecules maintained in heterologous host cells or purified (partially or substantially) DNA molecules in solution.

[0042] However, a nucleic acid molecule contained in a clone that is a member of a mixed clone library (e.g., a genomic or cDNA library) and that has not been isolated from other clones of the library (e.g., in the form of a homogeneous solution containing the clone without other members of the library) or a chromosome isolated or removed from a cell or a cell lysate (e.g., a chromosome spread, as in a karyotype), is not isolated for the purposes of this invention. Isolated RNA molecules include in vivo or in vitro RNA transcripts of the DNA molecules of the present invention. Isolated nucleic acid molecules according to the present invention further include such molecules produced synthetically.

[0043] Isolated nucleic acid molecules of the present invention include DR5 DNA molecules comprising, or alternatively consisting of, an open reading frame (ORF) shown in SEQ ID NO:1, DNA molecules comprising, or alternatively consisting of, the coding sequence for the mature DR5 protein; and DNA molecules which comprise, or alternatively consist of, a sequence substantially different from those described above, but which, due to the degeneracy of the genetic code, still encode the DR5 protein. Of course, the genetic code is well known in the art. Thus, it would be routine for one skilled in the art to generate such degenerate variants.

[0044] In addition, the invention provides nucleic acid molecules having nucleotide sequences related to extensive portions of SEQ ID NO:1 which have been determined from the following related cDNAs: HAPBU13R (SEQ ID NO:6) and HSBBU76R (SEQ ID NO:7). The nucleotide sequences of HAPBU13R and HSBBU76R are shown in FIG. 4.

[0045] The nucleotide sequence of an additional related polynucleotide which has been assigned GenBank Accession number Z66083 is shown in SEQ ID NO:14.

[0046] In another aspect, the invention provides isolated nucleic acid molecules encoding the DR5 polypeptide having an amino acid sequence encoded by the cDNA contained in the plasmid deposited as ATCC Deposit No. 97920 on Mar. 7, 1997. In a further embodiment, nucleic acid molecules are provided that encode the mature DR5 polypeptide or the full length DR5 polypeptide lacking the N-terminal methionine. The invention further provides an isolated nucleic acid molecule having the nucleotide sequence shown in SEQ ID NO:1 or the nucleotide sequence of the DR5 cDNA contained in the above-described deposited plasmid, or a nucleic acid molecule having a sequence complementary to one of the above sequences. Such isolated molecules, particularly DNA molecules, have uses which include, but are not limited to, as probes for gene mapping by in situ hybridization with chromosomes, and for detecting expression of the DR5 gene in human tissue, for instance, by Northern blot analysis.

[0047] The present invention is further directed to fragments of the isolated nucleic acid molecules described herein. By fragments of an isolated DNA molecule having the nucleotide sequence shown in SEQ ID NO:1 or having the nucleotide sequence of the deposited cDNA (the cDNA contained in the plasmid deposited as ATCC Deposit No. 97920) are intended DNA fragments at least 20 nt, and more preferably at least 30 nt in length, and even more preferably, at least about 40, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, or 1200 nucleotides in length, which are useful as DNA probes as discussed above. Of course, DNA fragments corresponding to most, if not all, of the nucleotide sequence shown in SEQ ID NO:1 are also useful as DNA probes. By a fragment at least about 20 nt in length, for example, is intended fragments which include 20 or more contiguous bases from the nucleotide sequence of the deposited DNA or the nucleotide sequence as shown in SEQ ID NO:1. In this context about includes the particularly recited size, larger or smaller by several (5, 4, 3, 2, or 1) nucleotides, at either terminus or at both termini.

[0048] Representative examples of DR5 polynucleotide fragments of the invention include, for example, fragments that comprise, or alternatively consist of, a sequence from about nucleotide 1-130, 130-180, 181-231, 232-282, 283-333, 334-384, 385-435, 436-486, 487-537, 538-588, 589-639, 640-681, 682-732, 733-753, 754-804, 805-855, 856-906, 907-957, 958-1008, 1009-1059, 1060-1098, 1099-1149, 1150-1200, 1201-1251, 1252-1302, 1303-1353, 1354-1362, and 1363 to the end of SEQ ID NO:1, or the complementary DNA strand thereto, or the cDNA contained in the deposited plasmid. In this context about includes the particularly recited ranges, larger or smaller by several (5, 4, 3, 2, or 1) nucleotides, at either terminus or at both termini. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0049] The present invention is further directed to polynucleotides comprising, or alternatively consisting of, isolated nucleic acid molecules which encode domains of DR5. In one aspect, the invention provides polynucleotides comprising, or alternatively consisting of, nucleic acid molecules which encode beta-sheet regions of DR5 protein set out in Table I. Representative examples of such polynucleotides include nucleic acid molecules which encode a polypeptide comprising, or alternatively consisting of, one, two, three, four, five, or more amino acid sequences selected from the group consisting of amino acid residues from about 16 to about 2, amino acid residues from about 2 to about 9, amino acid residues from about 60 to about 67, amino acid residues from about 135 to about 151, amino acid residues from about 193 to about 199, and amino acid residues from about 302 to about 310 in SEQ ID NO:2. In this context about includes the particularly recited value and values larger or smaller by several (5, 4, 3, 2, or 1) amino acid residues. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0050] In specific embodiments, the polynucleotide fragments of the invention encode a polypeptide which demonstrates a DR5 functional activity. By a polypeptide demonstrating a DR5 functional activity is meant, a polypeptide capable of displaying one or more known functional activities associated with a complete (full-length) or mature DR5 polypeptide, as well as secreted forms of DR5. Such functional activities include, but are not limited to, biological activity (e.g., ability to induce apoptosis in cells expressing the polypeptide (see e.g., Example 5)), antigenicity (ability to bind (or compete with a DR5 polypeptide for binding) to an anti-DR5 antibody), immunogenicity (ability to generate antibody which binds to a DR5 polypeptide), ability to form multimers, and ability to bind to a receptor or ligand for a DR5 polypeptide (e.g., TRAIL; Wiley et al, Immunity 3, 673-682 (1995)).

[0051] The functional activity of DR5 polypeptides, and fragments, variants derivatives, and analogs thereof, can be assayed by various methods.

[0052] For example, in one embodiment where one is assaying for the ability to bind or compete with full-length (complete) DR5 polypeptide for binding to anti-DR5 antibody, various immunoassays known in the art can be used, including but not limited to, competitive and non-competitive assay systems using techniques such as radioimmunioassays, ELISA (enzyme linked immunosorbent assay), sandwich immunoassays, immunoradiometric assays, gel diffusion precipitation reactions, immunodiffusion assays, in situ immunoassays (using colloidal gold, enzyme or radioisotope labels, for example), western blots, precipitation reactions, agglutination assays (e.g., gel agglutination assays, hemagglutination assays), complement fixation assays, immunofluorescence assays, protein A assays, and immunoelectrophoresis assays, etc. In one embodiment, antibody binding is detected by detecting a label on the primary antibody. In another embodiment, the primary antibody is detected by detecting binding of a secondary antibody or reagent to the primary antibody. In a further embodiment, the secondary antibody is labeled. Many means are known in the art for detecting binding in an immunoassay and are within the scope of the present invention.

[0053] In another embodiment, where a DR5 ligand is identified (e.g. TRAIL), or the ability of a polypeptide fragment, variant or derivative of the invention to multimerize is being evaluated, binding can be assayed, e.g., by means well-known in the art, such as, for example, reducing and non-reducing gel chromatography, protein affinity chromatography, and affinity blotting. See generally, Phizicky, et al., Microbiol. Rev. 59:94-123 (1995). In another embodiment, physiological correlates of DR5 binding to its substrates (signal transduction) can be assayed.

[0054] In addition, assays described herein (see Examples 5 and 6), and otherwise known in the art may routinely be applied to measure the ability of DR5 polypeptides and fragments, variants derivatives and analogs thereof to elicit DR5 related biological activity (e.g., ability to induce apoptosis in cells expressing the polypeptide (see e.g., Example 5), and the ability to bind a ligand, e.g., TRAIL (see, e.g., Example 6) in vitro or in vivo). For example, biological activity can routinely be measured using the cell death assays performed essentially as previously described (Chinnaiyan et al., Cell 81:505-512 (1995); Boldin et al., J. Biol. Chem. 270:7795-8(1995); Kischkel et al., EMBO 14:5579-5588 (1995); Chinnaiyan et al., J Biol. Chem. 271:4961-4965 (1996)) and as set forth in Example 5 below. In one embodiment involving MCF7 cells, plasmids encoding full-length DR5 or a candidate death domain containing receptor are co-transfected with the pLantern reporter construct encoding green fluorescent protein. Nuclei of cells transfected with DR5 will exhibit apoptotic morphology as assessed by DAPI staining.

[0055] Other methods will be known to the skilled artisan and are within the scope of the invention.

[0056] Preferred nucleic acid fragments of the present invention include, but are not limited to, a nucleic acid molecule encoding a polypeptide comprising, or alternatively consisting of, one, two, three, four, five, or more amino acid sequences selected from the group consisting of: a polypeptide comprising, or alternatively consisting of, the DR5 extracellular domain (amino acid residues from about 52 to about 184 in FIG. 1 (amino acid residues from about 1 to about 133 in SEQ ID NO:2)); a polypeptide comprising, or alternatively consisting of, the DR5 transmembrane domain (amino acid residues from about 185 to about 208 in FIG. 1 (amino acid residues from about 134 to about 157 in SEQ ID NO:2)); a polypeptide comprising, or alternatively consisting of, the cysteine rich domain of DR5 (amino acid residues from about 84 to about 179 in FIG. 1 (from about 33 to about 128 in SEQ ID NO:2)); a polypeptide comprising, or alternatively consisting of, the DR5 intracellular domain (amino acid residues from about 209 to about 411 in FIG. 1 (amino acid residues from about 158 to about 360 in SEQ ID NO:2)); a polypeptide comprising, or alternatively consisting of, a fragment of the predicted mature DR5 polypeptide, wherein the fragment has a DR5 functional activity (e.g., antigenic activity or biological activity); a polypeptide comprising, or alternatively consisting of, the DR5 receptor extracellular and intracellular domains with all or part of the transmembrane domain deleted; a polypeptide comprising, or alternatively consisting of, the DR5 death domain (amino acid residues from about 324 to about 391 in FIG. 1 (from about 273 to about 340 in SEQ ID NO:2)); and a polypeptide comprising, or alternatively consisting of, one, two, three, four or more, epitope bearing portions of the DR5 receptor protein. In additional embodiments, the polynucleotide fragments of the invention encode a polypeptide comprising, or alternatively consisting of, any combination of 1, 2, 3, 4, 5, 6, 7, or all 8 of the above members.

[0057] Since the location of these domains have been predicted by computer graphics, one of ordinary skill would appreciate that the amino acid residues constituting these domains may vary slightly (e.g., by about 1 to 15 residues) depending on the criteria used to define each domain. Polypeptides encoded by these nucleic acid molecules are also encompassed by the invention.

[0058] It is believed one or both of the extracellular cysteine rich motifs of DR5 disclosed in FIG. 1 is important for interactions between DR5 and its ligands (e.g., TRAIL). Accordingly, specific embodiments of the invention are directed to polynucleotides encoding a polypeptide comprising, or alternatively consisting of, one or both amino acid sequences selected from the group consisting of: amino acid residues 84 to 131, and/or 132 to 179 of the DR5 sequence shown in FIG. 1 (amino acid residues 33 to 80, and/or 81 to 128 in SEQ ID NO:2). In a specific embodiment the polynucleotides encoding DR5 polypeptides of the invention comprise, or alternatively consist of, both of the extracellular cysteine-rich motifs disclosed in FIG. 1.

[0059] In certain embodiments, polynucleotides of the invention comprise, or alternatively consist of, a polynucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to the polynucleotide sequence encoding the cysteine-rich domain described above. The present invention also encompasses the above polynucleotide sequences fused to a heterologous polynucleotide sequence. Polypeptides encoded by these polynucleotides are also encompassed by the invention. Methods to measure the percent identity of a polynucleotide sequence to a reference polynucleotide sequence are described infra.

[0060] In another embodiment, the invention provides an isolated nucleic acid molecule comprising, or alternatively consisting of, a polynucleotide which hybridizes under stringent hybridization conditions to nucleic acids complementary to the cysteine-rich domain encoding polynucleotides described above. The meaning of the phrase stringent conditions as used herein is described infra. Polypeptides encoded by such polynucleotides are also contemplated by the invention.

[0061] Preferred nucleic acid fragments of the invention encode a full-length DR5 polypeptide lacking the nucleotides encoding the amino-terminal methionine (nucleotides 130-132 in SEQ ID NO:1) as it is known that the methionine is cleaved naturally and such sequences maybe useful in genetically engineering DR5 expression vectors. Polypeptides encoded by such polynucleotides are also contemplated by the invention.

[0062] In additional embodiments, the polynucleotides of the invention encode functional attributes of DR5. Preferred embodiments of the invention in this regard include fragments that comprise, or alternatively consist of, one, two, three, four, or more of the following functional domains: alpha-helix and alpha-helix forming regions (alpha-regions), beta-sheet and beta-sheet forming regions (beta-regions), turn and turn-forming regions (turn-regions), coil and coil-forming regions (coil-regions), hydrophilic regions, hydrophobic regions. alpha-amphipathic regions, beta-amphipathic regions, flexible regions, surface-forming regions and high antigenic index regions of DR5.

[0063] The data representing the structural or functional attributes of DR5 set forth in FIG. 3 and/or Table I, as described above, were generated using the various identified modules and algorithms of tile DNA*STAR set on default parameters. In a preferred embodiment, the data presented in columns VIII, IX. XIII, and XIV of Table I can be used to determine regions of DR5 which exhibit a high degree of potential for antigenicity. Regions of high antigenicity are determined from the data presented in columns VIII, IX, XIII, and/or XIV by choosing values which represent regions of the polypeptide which are likely to be exposed on the surface of the polypeptide in an environment in which antigen recognition may occur in the process of initiation of an immune response.

[0064] Certain preferred regions in these regards are set out in FIG. 3. but may, as shown in Table I, be represented or identified by using tabular representations of the data presented in FIG. 3. The DNA*STAR computer algorithm used to generate FIG. 3 (set on the original default parameters) was used to present the data in FIG. 3 in a tabular format (See Table I). The tabular format of the data in FIG. 3 may be used to easily determine specific boundaries of a preferred region.

[0065] The above-mentioned preferred regions set out in FIG. 3 and in Table I include, but are not limited to, regions of the aforementioned types identified by analysis of the amino acid sequence set out in SEQ ID NO:2. As set out in FIG. 3 and in Table I, such preferred regions include Garnier-Robson alpha-regions, beta-regions, turn-regions, and coil-regions (columns I, III, V, and VII in Table I), Chou-Fasman alpha-regions, beta-regions, and turn-regions (columns II, IV, and VI in Table I), Kyte-Doolittle hydrophilic regions (column VIII in Table I), Hopp-Woods hydrophobic regions (column IX in Table I), Eisenberg alpha- and beta-amphipathic regions (columns X and XI in Table I), Karplus-Schulz flexible regions (column XII in Table I), Jameson-Wolf regions of high antigenic index (column XIII in Table I), and Emini surface-forming regions (column XIV in Table I).

TABLE I
Res	Position	I	II	III	IV	V	VI	VII	VIII	IX	X	XI	XII	XIII	XIV
Met	1	A	.	.	.	.	.	.	1.11	0.70	.	*	.	1.29	2.18
Glu	2	A	.	.	.	.	.	.	1.50	0.70	.	*	.	1.63	1.69
Gln	3	A	.	.	.	.	T	.	1.89	0.73	.	*	.	2.17	2.28
Arg	4	.	.	.	.	T	T	.	1.69	0.76	.	*	.	2.91	3.71
Gly	5	.	.	.	.	T	T	.	1.87	0.87	.	*	F	3.40	2.17
Gln	6	.	.	.	.	T	T	.	1.88	0.44	.	*	F	2.76	1.93
Asn	7	.	.	.	.	.	.	C	1.29	0.34	.	*	F	1.87	1.00
Ala	8	.	.	.	.	.	.	C	0.99	0.16	.	.	F	1.08	1.02
Pro	9	.	.	.	.	.	.	C	0.53	0.11	.	*	.	0.44	0.79
Ala	10	A	.	.	.	.	.	.	0.29	0.14	.	*	.	0.10	0.48
Ala	11	A	.	.	.	.	T	.	0.40	0.24	.	.	.	0.10	0.48
Ser	12	A	.	.	.	.	T	.	0.44	0.26	.	*	F	0.85	0.61
Gly	13	A	.	.	.	.	T	.	1.14	0.69	.	*	F	1.30	1.22
Ala	14	A	.	.	.	.	T	.	1.32	1.19	.	*	F	1.30	2.36
Arg	15	A	.	.	.	T	.	.	1.57	1.19	.	*	F	1.50	2.39
Lys	16	.	.	.	.	T	.	.	1.94	1.14	.	.	F	1.50	2.39
Arg	17	.	.	.	.	T	.	.	1.90	1.14	.	*	F	1.80	3.66
His	18	.	.	.	.	.	.	C	2.03	1.21	*	*	F	1.90	1.85
Gly	19	.	.	.	.	.	T	C	2.73	0.79	*	*	F	2.40	1.43
Pro	20	.	.	.	.	.	T	C	2.62	0.79	*	*	F	2.70	1.43
Gly	21	.	.	.	.	.	T	C	1.99	0.79	*	.	F	3.00	1.82
Pro	22	.	.	.	.	.	T	C	1.99	0.79	.	*	F	2.70	1.86
Arg	23	.	A	.	.	.	.	C	1.68	1.21	*	.	F	2.30	2.35
Glu	24	.	A	B	.	.	.	.	1.43	1.21	*	.	F	2.10	2.35
Ala	25	.	A	.	.	T	.	.	1.76	1.14	*	.	F	2.50	1.54
Arg	26	.	A	.	.	T	.	.	1.89	1.57	*	.	F	2.50	1.54
Gly	27	.	.	.	.	T	.	.	1.76	1.14	*	.	F	3.00	1.37
Ala	28	.	.	.	.	T	.	C	1.43	0.71	*	*	F	2.70	1.35
Arg	29	.	.	.	.	.	T	C	1.54	0.79	*	*	F	2.66	1.06
Pro	30	.	.	.	.	.	T	C	1.28	0.79	*	*	F	2.62	2.10
Gly	31	.	.	.	.	.	T	C	0.96	0.57	*	*	F	2.58	1.54
Pro	32	.	.	.	.	.	T	C	1.34	0.64	*	*	F	2.54	1.22
Arg	33	.	.	.	.	.	.	C	1.62	0.64	*	*	F	2.60	1.58
Val	34	.	.	.	.	.	.	C	0.70	0.59	*	*	F	2.34	2.30
Pro	35	.	.	B	.	.	.	.	0.06	0.33	*	*	F	1.58	1.23
Lys	36	.	.	B	B	.	.	.	0.41	0.11	*	.	F	0.97	0.46
Thr	37	.	.	B	B	.	.	.	1.06	0.57	*	*	F	0.19	0.52
Leu	38	.	.	B	B	.	.	.	2.02	0.57	*	*	.	0.60	0.25
Val	39	.	.	B	B	.	.	.	1.76	0.79	.	.	.	0.60	0.09
Leu	40	A	.	.	B	.	.	.	2.13	1.29	.	.	.	0.60	0.06
Val	41	A	.	.	B	.	.	.	3.03	1.30	.	.	.	0.60	0.08
Val	42	A	.	.	B	.	.	.	3.53	1.26	.	.	.	0.60	0.08
Ala	43	A	.	.	B	.	.	.	3.53	1.30	.	.	.	0.60	0.08
Ala	44	A	.	.	B	.	.	.	3.49	1.30	.	.	.	0.60	0.09
Val	45	A	.	.	B	.	.	.	3.53	1.34	.	.	.	0.60	0.10
Leu	46	A	.	.	B	.	.	.	2.98	1.34	.	.	.	0.60	0.07
Leu	47	A	.	.	B	.	.	.	2.71	1.23	.	.	.	0.60	0.09
Leu	48	A	.	.	B	.	.	.	2.12	1.23	.	.	.	0.60	0.13
Val	49	A	.	.	B	.	.	.	1.83	0.59	.	.	.	0.60	0.27
Ser	50	A	.	.	B	.	.	.	1.57	0.29	.	*	.	0.30	0.44
Ala	51	A	A	.	.	.	.	.	1.57	0.10	.	.	.	0.30	0.54
Glu	52	A	A	.	.	.	.	.	1.64	0.10	.	.	.	0.30	0.60
Ser	53	A	A	.	B	.	.	.	1.14	0.14	.	.	.	0.30	0.31
Ala	54	A	A	.	B	.	.	.	0.29	0.24	.	.	.	0.30	0.45
Leu	55	A	A	.	B	.	.	.	0.01	0.14	.	.	.	0.30	0.45
Ile	56	A	A	.	B	.	.	.	0.60	0.54	.	.	.	0.60	0.58
Thr	57	A	A	.	B	.	.	.	0.21	0.16	.	.	F	0.15	0.96
Gln	58	A	A	.	B	.	.	.	0.50	0.34	.	.	F	0.15	0.96
Gln	59	A	A	.	B	.	.	.	0.12	0.16	.	.	F	0.00	1.38
Asp	60	.	A	.	B	T	.	.	0.69	0.10	.	.	F	1.00	1.48
Leu	61	.	A	.	.	.	.	C	1.58	0.19	.	*	F	0.80	1.48
Ala	62	.	A	.	.	.	.	C	2.00	0.19	.	*	F	0.80	1.48
Pro	63	.	A	.	.	.	.	C	1.41	0.59	.	*	F	1.10	1.73
Gln	64	.	A	.	.	T	.	.	0.82	0.09	.	*	F	1.00	2.13
Gln	65	A	A	.	.	.	.	.	0.61	0.27	.	*	F	0.60	2.13
Arg	66	A	A	.	.	.	.	.	1.42	0.34	.	*	F	0.60	2.13
Ala	67	A	A	.	.	.	.	.	2.01	0.37	.	*	F	0.94	2.13
Ala	68	A	A	.	.	.	.	.	2.27	0.37	*	*	F	1.28	2.13
Pro	69	A	A	.	.	.	.	.	2.38	0.77	*	*	F	1.92	2.17
Gln	70	.	A	.	.	T	.	.	2.08	0.77	*	.	F	2.66	4.21
Gln	71	.	.	.	.	T	T	.	1.67	0.89	*	*	F	3.40	5.58
Lys	72	.	.	.	.	T	T	.	2.04	1.00	.	.	F	3.06	4.84
Arg	73	.	.	.	.	T	T	.	2.33	1.00	.	.	F	2.97	4.32
Ser	74	.	.	.	.	.	T	C	2.54	1.01	.	.	F	2.68	3.34
Ser	75	.	.	.	.	.	T	C	2.20	1.41	.	.	F	2.59	2.89
Pro	76	.	.	.	.	T	T	.	1.39	0.99	.	.	F	2.70	1.46
Ser	77	.	.	.	.	T	T	.	0.68	0.30	.	.	F	2.50	0.90
Glu	78	.	.	.	.	T	T	.	0.36	0.11	.	*	F	2.25	0.36
Gly	79	.	.	.	.	T	.	.	0.44	0.07	.	.	F	1.80	0.36
Leu	80	.	.	.	.	T	.	.	0.40	0.07	.	.	F	1.55	0.42
Cys	81	.	.	.	.	.	.	C	0.58	0.03	.	.	.	0.95	0.24
Pro	82	.	.	.	.	.	T	C	0.84	0.47	*	.	F	0.15	0.33
Pro	83	.	.	.	.	T	T	.	0.04	0.54	*	.	F	0.35	0.54
Gly	84	.	.	.	.	T	T	.	0.00	0.54	*	.	.	0.20	0.70
His	85	.	.	.	.	.	T	C	0.81	0.36	*	.	.	0.30	0.61
His	86	.	.	.	.	.	.	C	1.48	0.07	*	.	.	0.70	0.68
Ile	87	.	.	.	.	.	.	C	1.34	0.50	*	*	.	1.19	1.15
Ser	88	.	.	.	.	.	.	C	1.67	0.50	*	*	F	1.53	0.84
Glu	89	.	.	.	.	T	.	.	2.01	1.00	*	*	F	2.52	1.21
Asp	90	.	.	.	.	T	.	.	1.38	1.50	*	*	F	2.86	2.88
Gly	91	.	.	.	.	T	T	.	0.52	1.61	*	*	F	3.40	1.15
Arg	92	.	.	.	.	T	T	.	1.11	1.31	*	*	F	2.91	0.47
Asp	93	.	.	.	.	T	T	.	0.74	0.93	.	*	F	2.57	0.37
Cys	94	.	.	.	.	T	T	.	0.79	0.36	.	*	.	1.78	0.20
Ile	95	.	.	.	.	T	.	.	0.54	0.79	.	*	.	1.54	0.21
Ser	96	.	.	.	.	T	.	.	0.54	0.03	.	*	.	1.18	0.19
Cys	97	.	.	.	.	T	T	.	0.43	0.40	.	*	.	0.76	0.36
Lys	98	.	.	.	.	T	T	.	0.43	0.23	.	.	.	1.34	0.88
Tyr	99	.	.	.	.	T	T	.	0.86	0.46	.	*	F	2.52	1.10
Gly	100	.	.	.	.	T	T	.	1.44	0.09	.	*	F	2.80	3.22
Gln	101	.	.	.	.	T	T	.	1.43	0.27	*	.	F	2.52	2.16
Asp	102	.	.	.	.	T	T	.	2.07	0.21	*	*	F	1.64	1.99
Tyr	103	.	.	.	.	T	T	.	1.73	0.04	*	*	F	1.96	2.73
Ser	104	.	.	.	.	T	T	.	1.98	0.44	*	.	F	0.78	1.66
Thr	105	.	.	.	.	T	.	.	2.32	0.44	*	.	F	0.30	1.60
His	106	.	.	.	.	T	.	.	1.51	0.44	*	.	.	0.15	1.70
Trp	107	.	.	.	.	T	T	.	0.70	0.37	*	.	.	0.65	1.05
Asn	108	.	.	.	.	T	T	.	0.24	0.67	.	.	.	0.20	0.60
Asp	109	.	.	.	.	T	T	.	0.12	0.97	*	.	.	0.20	0.38
Leu	110	A	.	.	.	.	T	.	0.62	1.04	*	*	.	0.20	0.19
Leu	111	.	.	.	B	T	.	.	0.48	0.81	*	*	.	0.20	0.10
Phe	112	.	.	.	B	T	.	.	0.86	0.41	*	*	.	0.20	0.12
Cys	113	.	.	.	B	T	.	.	1.17	0.99	*	*	.	0.20	0.08
Leu	114	.	.	.	B	T	.	.	1.06	0.79	.	*	.	0.20	0.13
Arg	115	.	.	.	B	T	.	.	0.91	0.10	.	*	.	0.10	0.30
Cys	116	.	.	.	B	T	.	.	0.10	0.11	.	.	.	0.70	0.30
Thr	117	.	.	.	B	T	.	.	0.30	0.69	.	*	.	1.00	0.61
Arg	118	.	.	.	B	T	.	.	0.62	0.99	.	.	F	1.49	0.42
Cys	119	.	.	.	.	T	T	.	1.43	0.56	*	.	F	2.23	0.77
Asp	120	.	.	.	.	T	T	.	0.47	1.13	*	.	F	2.57	0.92
Ser	121	.	.	.	.	T	T	.	1.13	0.97	.	*	F	2.91	0.35
Gly	122	.	.	.	.	T	T	.	0.63	0.97	.	*	F	3.40	1.13
Glu	123	.	A	.	.	T	.	.	0.22	0.86	.	*	F	2.51	0.56
Val	124	A	A	.	.	.	.	.	0.68	0.47	.	*	F	1.47	0.56
Glu	125	.	A	.	.	T	.	.	0.01	0.43	.	*	.	1.38	0.87
Leu	126	.	A	.	.	T	.	.	0.00	0.29	.	*	.	1.04	0.27
Ser	127	.	.	.	.	.	T	C	0.03	0.20	.	*	F	0.45	0.52
Pro	128	.	.	.	.	T	T	.	0.28	0.04	.	*	F	0.93	0.44
Cys	129	.	.	.	.	T	T	.	0.69	0.53	.	*	F	0.91	0.77
Thr	130	.	.	.	.	T	T	.	0.69	0.16	.	*	F	2.24	1.12
Thr	131	.	.	.	.	T	.	.	1.19	0.14	.	*	F	2.32	1.16
Thr	132	.	.	.	.	T	T	.	0.63	0.09	.	*	F	2.80	3.13
Arg	133	.	.	.	.	T	T	.	0.18	0.01	.	.	F	2.52	1.61
Asn	134	.	.	.	.	T	T	.	0.84	0.07	.	.	F	1.49	0.60
Thr	135	.	.	.	.	T	T	.	0.49	0.01	.	.	F	1.81	0.72
Val	136	.	.	.	.	T	.	C	0.80	0.07	*	.	.	0.58	0.20
Cys	137	.	A	.	.	T	.	.	1.11	0.07	*	.	.	0.10	0.21
Gln	138	.	A	B	.	.	.	.	0.66	0.33	*	.	.	0.30	0.25
Cys	139	.	A	.	.	T	.	.	0.34	0.39	.	.	.	0.70	0.34
Glu	140	A	A	.	.	.	.	.	0.04	0.54	*	*	F	0.75	0.91
Glu	141	A	A	.	.	.	.	.	0.92	0.33	*	*	F	0.45	0.46
Gly	142	.	A	.	.	T	.	.	1.59	0.73	.	*	F	1.30	1.67
Thr	143	A	A	.	.	.	.	.	1.59	1.30	.	*	F	0.90	1.67
Phe	144	A	A	.	.	.	.	.	2.26	1.30	.	*	F	0.90	1.67
Arg	145	A	A	.	.	.	.	.	1.96	1.30	.	*	F	0.90	2.81
Glu	146	A	A	.	.	.	.	.	1.74	1.34	.	*	F	0.90	2.61
Glu	147	A	A	.	.	.	.	.	2.09	1.40	.	*	F	0.90	4.66
Asp	148	A	A	.	.	.	.	.	1.80	2.19	.	*	F	0.90	4.12
Ser	149	A	.	.	.	.	T	.	1.83	1.57	.	*	F	1.30	2.35
Pro	150	A	.	.	.	.	T	.	1.83	1.00	.	.	F	1.15	0.73
Glu	151	A	.	.	.	.	T	.	1.88	1.00	*	.	F	1.15	0.85
Met	152	A	.	.	.	.	T	.	1.21	1.00	*	*	.	1.49	1.28
Cys	153	A	.	.	.	.	T	.	1.32	0.81	*	*	.	1.68	0.44
Arg	154	A	.	.	.	.	T	.	1.31	1.24	*	.	.	2.02	0.50
Lys	155	.	.	.	.	T	T	.	1.18	0.76	*	*	F	2.91	0.73
Cys	156	.	.	.	.	T	T	.	0.51	0.94	*	.	F	3.40	1.35
Arg	157	.	.	.	.	T	.	.	0.90	0.94	*	.	F	2.71	0.37
Thr	158	.	.	.	.	T	.	.	1.68	0.51	*	.	F	2.37	0.28
Gly	159	.	.	.	.	T	.	.	1.22	0.51	*	.	F	2.43	1.04
Cys	160	.	.	.	.	.	T	C	0.58	0.66	.	*	F	2.19	0.53
Pro	161	.	.	.	.	T	T	.	0.39	0.04	.	*	F	2.00	0.36
Arg	162	.	.	.	.	T	T	.	0.32	0.11	.	*	F	1.65	0.27
Gly	163	.	.	.	.	T	T	.	0.22	0.31	*	*	.	2.50	1.01
Met	164	.	.	B	B	.	.	.	0.22	0.24	*	*	.	1.30	0.48
Val	165	.	.	B	B	.	.	.	0.44	0.24	*	*	.	1.30	0.24
Lys	166	.	.	B	B	.	.	.	0.01	0.24	*	*	.	1.30	0.41
Val	167	.	.	B	.	.	T	.	0.43	0.10	*	*	F	1.85	0.22
Gly	168	.	.	.	.	T	T	.	0.30	0.23	.	.	F	2.25	0.44
Asp	169	.	.	.	.	T	T	.	0.01	0.44	.	.	F	2.50	0.34
Cys	170	.	.	.	.	T	T	.	0.57	0.47	.	*	F	1.35	0.48
Thr	171	.	.	.	.	.	T	C	0.52	0.21	.	*	F	1.20	0.65
Pro	172	.	.	.	.	T	T	.	0.49	0.21	.	*	F	1.75	0.65
Trp	173	.	.	.	.	T	T	.	0.83	0.47	.	*	F	0.60	0.84
Ser	174	A	.	.	.	.	T	.	0.17	0.10	.	*	F	1.00	1.01
Asp	175	A	A	.	.	.	.	.	0.02	0.01	.	.	F	0.45	0.35
Ile	176	A	A	.	.	.	.	.	0.26	0.20	*	*	.	0.30	0.25
Glu	177	A	A	.	.	.	.	.	0.51	0.21	*	.	.	0.30	0.25
Cys	178	A	A	.	.	.	.	.	0.80	0.60	*	.	.	0.60	0.30
Val	179	A	A	.	.	.	.	.	0.80	0.60	*	*	.	0.60	0.74
His	180	A	A	.	.	.	.	.	0.46	0.90	.	*	.	0.60	0.58
Lys	181	A	A	.	.	.	.	.	0.46	0.47	*	.	F	0.60	1.06
Glu	182	A	.	.	.	.	T	.	0.43	0.36	*	.	F	1.00	1.00
Ser	183	A	.	.	.	.	T	.	0.66	0.31	.	.	F	0.85	0.52
Gly	184	A	.	.	.	T	T	.	0.14	0.13	.	.	F	1.25	0.18
Ile	185	A	.	.	.	.	T	.	0.97	0.30	.	.	.	0.10	0.10
Ile	186	.	.	B	B	.	.	.	1.32	0.94	.	*	.	0.60	0.06
Ile	187	.	.	B	B	.	.	.	2.18	1.04	.	.	.	0.60	0.08
Gly	188	.	.	B	B	.	.	.	2.47	1.26	.	*	.	0.60	0.09
Val	189	.	.	B	B	.	.	.	2.71	1.07	.	.	.	0.60	0.13
Thr	190	A	.	.	B	.	.	.	2.68	0.89	.	*	.	0.60	0.18
Val	191	A	.	.	B	.	.	.	2.64	0.84	.	.	.	0.60	0.14
Ala	192	A	.	.	B	.	.	.	2.57	1.06	.	*	.	0.60	0.14
Ala	193	A	.	.	B	.	.	.	3.11	1.10	.	.	.	0.60	0.08
Val	194	A	.	.	B	.	.	.	3.11	1.30	.	.	.	0.60	0.07
Val	195	A	.	.	B	.	.	.	3.39	1.30	.	.	.	0.60	0.05
Leu	196	A	.	.	B	.	.	.	3.39	1.30	.	.	.	0.60	0.05
Ile	197	A	.	.	B	.	.	.	3.50	1.44	.	.	.	0.60	0.05
Val	198	A	.	.	B	.	.	.	3.77	1.59	.	.	.	0.60	0.06
Ala	199	A	.	.	B	.	.	.	3.58	1.59	.	.	.	0.60	0.06
Val	200	A	.	.	B	.	.	.	2.68	1.47	.	.	.	0.60	0.04
Phe	201	A	.	.	B	.	.	.	2.17	0.79	.	.	.	0.60	0.12
Val	202	A	.	.	B	.	.	.	2.09	0.53	.	.	.	0.60	0.16
Cys	203	A	.	.	.	.	T	.	2.04	0.71	.	.	.	0.20	0.17
Lys	204	A	.	.	.	.	T	.	1.74	0.76	.	.	.	0.20	0.17
Ser	205	A	.	.	.	.	T	.	0.84	0.89	.	.	.	0.20	0.24
Leu	206	A	.	.	.	.	T	.	0.10	0.24	.	.	.	0.10	0.88
Leu	207	A	A	.	.	.	.	.	0.10	0.33	.	.	.	0.30	0.88
Trp	208	A	A	.	.	.	.	.	0.24	0.31	.	.	.	0.30	0.49
Lys	209	A	A	.	.	.	.	.	0.50	0.61	.	.	.	0.60	0.49
Lys	210	A	A	.	.	.	.	.	0.44	0.36	*	.	.	0.30	0.91
Val	211	A	A	.	.	.	.	.	0.44	0.43	*	*	.	0.45	1.36
Leu	212	.	A	B	.	.	.	.	0.41	0.20	*	*	.	0.30	0.56
Pro	213	.	A	B	.	.	.	.	0.36	0.20	*	.	.	0.30	0.56
Tyr	214	.	.	.	B	T	.	.	0.58	0.63	*	.	.	0.20	0.75
Leu	215	.	.	.	B	T	.	.	1.29	0.67	*	*	.	0.20	0.64
Lys	216	.	.	.	B	T	.	.	0.73	0.56	*	.	.	0.20	0.22
Gly	217	.	.	B	B	.	.	.	0.27	0.51	*	.	.	0.60	0.19
Ile	218	.	.	B	B	.	.	.	0.40	0.19	*	.	.	0.30	0.23
Cys	219	.	.	B	.	.	T	.	0.50	0.07	*	.	.	0.70	0.11
Ser	220	.	.	.	.	T	T	.	0.03	0.36	.	*	F	0.65	0.11
Gly	221	.	.	.	.	T	T	.	0.08	0.36	.	.	F	0.65	0.16
Gly	222	.	.	.	.	T	T	.	0.06	0.33	.	.	F	1.25	0.49
Gly	223	.	.	.	.	.	.	C	0.94	0.47	.	.	F	0.85	0.57
Gly	224	.	.	.	.	.	.	C	1.72	0.86	*	.	F	1.15	0.99
Asp	225	.	.	.	.	.	T	C	1.17	1.29	.	*	F	1.50	1.97
Pro	226	.	.	.	.	.	T	C	1.51	1.07	*	.	F	1.84	1.47
Glu	227	.	.	B	.	.	T	.	1.97	1.50	*	.	F	1.98	2.49
Arg	228	.	.	B	.	.	T	.	2.01	1.93	*	.	F	2.32	2.92
Val	229	.	.	.	.	T	.	.	2.06	1.54	*	.	F	2.86	2.53
Asp	230	.	.	.	.	T	T	.	2.06	1.59	*	.	F	3.40	1.96
Arg	231	.	.	.	.	T	T	.	2.38	1.19	*	*	F	3.06	1.73
Ser	232	.	.	.	.	T	T	.	2.17	1.19	*	.	F	2.72	4.57
Ser	233	.	.	.	.	T	T	.	1.71	1.40	*	*	F	2.72	4.23
Gln	234	.	.	.	.	.	.	C	1.98	0.97	*	*	F	2.32	2.14
Arg	235	.	.	.	.	.	T	C	1.98	0.47	*	*	F	2.22	1.61
Pro	236	.	.	.	.	.	T	C	1.87	0.86	*	*	F	2.86	2.08
Gly	237	.	.	.	.	T	T	.	2.17	1.24	.	*	F	3.40	2.01
Ala	238	.	.	.	.	.	T	C	1.61	1.24	.	*	F	2.86	1.65
Glu	239	A	.	.	.	.	.	.	0.80	0.60	.	*	F	1.97	0.79
Asp	240	A	.	.	.	.	.	.	0.69	0.34	.	*	F	1.33	0.66
Asn	241	A	.	.	.	.	.	.	0.90	0.37	*	.	.	0.99	1.05
Val	242	A	.	.	.	.	.	.	0.36	0.87	*	.	.	0.95	1.05
Leu	243	A	.	.	.	.	.	.	0.09	0.19	*	.	.	0.50	0.44
Asn	244	A	.	.	B	.	.	.	0.21	0.46	*	.	.	0.60	0.20
Glu	245	A	.	.	B	.	.	.	1.10	0.44	*	.	.	0.60	0.37
Ile	246	A	.	.	B	.	.	.	1.91	0.49	*	.	.	0.60	0.31
Val	247	A	.	.	B	.	.	.	1.06	0.49	*	.	.	0.60	0.16
Ser	248	.	.	B	B	.	.	.	0.46	0.49	*	.	.	0.60	0.16
Ile	249	.	.	B	B	.	.	.	0.77	0.91	*	.	.	0.60	0.35
Leu	250	.	.	.	B	.	.	C	0.77	0.71	.	.	.	0.40	0.69
Gln	251	.	.	.	.	.	T	C	0.73	0.47	.	.	F	0.15	0.89
Pro	252	.	.	.	.	.	T	C	0.09	0.73	.	.	F	0.15	0.94
Thr	253	.	.	.	.	.	T	C	0.21	0.47	.	.	F	0.30	1.76
Gln	254	.	.	.	.	.	T	C	1.10	0.21	.	.	F	1.20	1.76
Val	255	.	A	.	.	.	.	C	1.91	0.21	.	.	F	0.80	1.97
Pro	256	.	A	.	.	.	.	C	1.31	0.64	.	.	F	1.10	2.37
Glu	257	A	A	.	.	.	.	.	1.52	0.51	.	*	F	0.90	1.35
Gln	258	A	A	.	.	.	.	.	0.98	0.91	.	*	F	0.90	3.16
Glu	259	A	A	.	.	.	.	.	0.98	0.91	.	*	F	0.90	1.51
Met	260	A	A	.	.	.	.	.	1.83	0.94	.	*	F	0.90	1.51
Glu	261	A	A	.	.	.	.	.	1.83	0.94	.	*	.	0.75	1.51
Val	262	A	A	.	.	.	.	.	1.24	0.91	.	*	F	0.90	1.35
Gln	263	A	A	.	.	.	.	.	1.24	0.41	.	*	F	0.60	1.38
Glu	264	A	A	.	.	.	.	.	1.03	1.03	.	*	F	0.90	1.38
Pro	265	A	A	.	.	.	.	.	1.32	0.60	.	*	F	1.18	2.88
Ala	266	A	A	.	.	.	.	.	0.98	0.76	.	*	F	1.46	2.40
Glu	267	A	.	.	.	.	T	.	0.98	0.73	.	*	F	2.14	1.37
Pro	268	A	.	.	.	.	T	.	0.98	0.09	.	.	F	1.97	0.66
Thr	269	.	.	.	.	T	T	.	0.38	0.11	.	.	F	2.80	1.05
Gly	270	A	.	.	.	.	T	.	0.22	0.00	.	.	F	1.37	0.60
Val	271	A	.	.	.	.	.	.	0.07	0.69	.	.	.	0.44	0.32
Asn	272	.	.	B	.	.	.	.	0.14	0.64	.	.	.	0.16	0.30
Met	273	.	.	B	.	.	.	.	0.28	0.59	.	.	.	0.18	0.46
Leu	274	.	.	.	.	.	.	C	0.03	0.59	.	.	.	0.40	0.62
Ser	275	.	.	.	.	.	T	C	0.08	0.06	.	.	F	1.95	0.66
Pro	276	.	.	.	.	.	T	C	0.93	0.07	.	.	F	2.25	0.90
Gly	277	.	.	.	.	.	T	C	0.90	0.69	.	.	F	3.00	1.89
Glu	278	A	.	.	.	.	T	.	0.69	0.87	.	.	F	2.50	1.92
Ser	279	A	A	.	.	.	.	.	0.69	0.57	.	.	F	1.80	1.02
Glu	280	A	A	.	.	.	.	.	0.99	0.31	.	.	F	1.05	0.85
His	281	A	A	.	.	.	.	.	0.99	0.74	.	.	F	1.05	0.85
Leu	282	A	A	.	.	.	.	.	0.74	0.31	.	.	.	0.30	0.98
Leu	283	A	A	.	.	.	.	.	0.74	0.20	.	.	.	0.30	0.57
Glu	284	A	A	.	.	.	.	.	0.46	0.20	.	.	F	0.45	0.73
Pro	285	A	A	.	.	.	.	.	0.46	0.20	.	.	F	0.45	0.89
Ala	286	A	A	.	.	.	.	.	0.60	0.89	.	.	F	0.90	1.88
Glu	287	A	A	.	.	.	.	.	1.11	1.57	.	.	F	0.90	2.13
Ala	288	A	A	.	.	.	.	.	1.92	1.19	.	.	F	0.90	1.84
Glu	289	A	A	.	.	.	.	.	2.03	1.21	*	.	F	0.90	3.16
Arg	290	A	A	.	.	.	.	.	2.36	1.71	*	.	F	0.90	3.57
Ser	291	A	.	.	.	.	T	.	3.06	1.71	*	.	F	1.30	6.92
Gln	292	A	.	.	.	.	T	.	2.24	2.21	*	.	F	1.30	7.83
Arg	293	A	.	.	.	.	T	.	2.02	1.53	.	.	F	1.30	3.30
Arg	294	A	.	.	.	.	T	.	1.17	0.84	.	.	F	1.30	2.03
Arg	295	.	.	.	B	T	.	.	0.84	0.59	.	*	F	1.15	0.87
Leu	296	.	.	B	B	.	.	.	0.56	0.56	.	*	.	0.60	0.69
Leu	297	.	.	B	B	.	.	.	0.56	0.06	.	*	.	0.30	0.35
Val	298	.	.	.	B	.	.	C	0.44	0.34	*	*	.	0.20	0.29
Pro	299	.	.	.	.	.	T	C	0.01	0.34	*	.	.	0.90	0.61
Ala	300	.	.	.	.	.	T	C	0.12	0.09	*	*	F	1.35	0.73
Asn	301	.	.	.	.	.	T	C	0.48	0.60	.	.	F	2.70	1.65
Glu	302	.	.	.	.	.	T	C	0.98	0.81	.	.	F	3.00	1.65
Gly	303	.	.	.	.	.	.	C	1.83	0.76	.	.	F	2.50	2.35
Asp	304	.	.	.	.	.	T	C	1.73	1.26	.	.	F	2.40	2.54
Pro	305	.	.	.	.	.	T	C	1.51	1.17	.	*	F	2.10	2.11
Thr	306	A	.	.	.	.	T	.	1.62	0.49	.	*	F	1.30	1.76
Glu	307	A	.	.	.	.	T	.	1.62	0.91	*	*	F	1.30	2.07
Thr	308	A	.	.	B	.	.	.	1.30	0.51	*	*	F	0.90	2.31
Leu	309	A	.	.	B	.	.	.	0.60	0.37	*	*	F	0.45	0.86
Arg	310	A	.	.	B	.	.	.	0.81	0.07	*	*	.	0.30	0.43
Gln	311	A	.	.	B	.	.	.	1.12	0.07	*	*	.	0.30	0.50
Cys	312	A	.	.	.	.	T	.	0.42	0.56	*	*	.	1.15	1.01
Phe	313	A	.	.	.	.	T	.	0.14	0.46	*	*	.	0.70	0.45
Asp	314	.	.	.	.	T	T	.	0.96	0.04	*	*	.	0.50	0.26
Asp	315	A	.	.	.	.	T	.	0.03	0.36	*	*	.	0.70	0.81
Phe	316	A	A	.	.	.	.	.	0.82	0.24	*	.	.	0.30	0.77
Ala	317	A	A	.	.	.	.	.	0.37	0.39	*	.	.	0.30	0.34
Asp	318	A	A	.	.	.	.	.	0.37	0.04	*	*	.	0.30	0.32
Leu	319	A	A	.	.	.	.	.	0.37	0.83	.	.	.	0.60	0.32
Val	320	.	A	.	.	.	.	C	0.67	0.04	.	.	.	0.10	0.52
Pro	321	.	A	.	.	.	.	C	0.26	0.07	.	.	.	0.50	0.42
Phe	322	.	.	.	.	T	T	.	0.33	0.84	.	.	.	0.20	0.54
Asp	323	A	.	.	.	.	T	.	0.12	0.16	.	.	.	0.25	1.25
Ser	324	A	.	.	.	.	T	.	0.12	0.06	.	.	F	1.00	1.25
Trp	325	A	.	.	.	.	T	.	0.38	0.20	*	*	F	0.40	1.19
Glu	326	A	A	.	.	.	.	.	0.70	0.03	*	.	F	0.15	0.71
Pro	327	A	A	.	.	.	.	.	1.44	0.03	*	.	.	0.15	1.03
Leu	328	A	A	.	.	.	.	.	0.63	0.36	*	.	.	0.45	1.96
Met	329	A	A	.	.	.	.	.	0.59	0.59	*	.	.	0.60	0.93
Arg	330	A	A	.	.	.	.	.	0.07	0.16	*	.	.	0.30	0.60
Lys	331	A	A	.	.	.	.	.	0.53	0.10	*	.	.	0.30	0.60
Leu	332	A	A	.	.	.	.	.	0.32	0.03	*	.	.	0.30	0.60
Gly	333	A	A	.	.	.	.	.	0.49	0.59	*	.	.	0.60	0.51
Leu	334	A	A	.	.	.	.	.	1.09	0.19	*	.	.	0.30	0.41
Met	335	A	A	.	.	.	.	.	0.09	0.19	*	*	.	0.30	0.86
Asp	336	A	A	.	.	.	.	.	0.09	0.19	.	*	F	0.45	0.61
Asn	337	A	A	.	.	.	.	.	0.04	0.61	*	*	F	0.90	1.48
Glu	338	A	A	.	.	.	.	.	0.20	0.66	*	*	F	0.90	1.11
Ile	339	A	A	.	.	.	.	.	0.66	0.77	*	*	F	0.75	0.67
Lys	340	A	A	.	.	.	.	.	0.67	0.77	.	*	F	0.75	0.83
Val	341	A	A	.	.	.	.	.	0.67	0.67	.	*	.	0.60	0.49
Ala	342	A	A	.	.	.	.	.	0.08	0.67	.	.	.	0.75	1.20
Lys	343	A	A	.	.	.	.	.	0.51	0.86	.	*	.	0.60	0.61
Ala	344	A	A	.	.	.	.	.	0.03	0.36	.	*	.	0.30	0.83
Glu	345	A	A	.	.	.	.	.	0.04	0.57	*	.	.	0.60	0.81
Ala	346	A	A	.	.	.	.	.	0.92	0.57	*	.	.	0.60	0.55
Ala	347	A	A	.	.	.	.	.	1.51	0.57	.	*	.	0.75	1.07
Gly	348	A	.	.	.	.	.	.	1.16	1.07	.	*	.	0.95	1.03
His	349	A	.	.	.	.	T	.	0.93	0.59	.	.	.	1.15	1.47
Arg	350	A	.	.	.	.	T	.	0.69	0.40	.	.	F	1.00	1.20
Asp	351	A	.	.	.	.	T	.	0.97	0.14	.	.	F	1.00	1.90
Thr	352	A	.	.	.	.	T	.	0.96	0.09	.	.	F	1.00	2.02
Leu	353	A	.	.	B	.	.	.	0.49	0.03	.	.	.	0.15	1.02
Tyr	354	A	.	.	B	.	.	.	0.37	0.71	.	*	.	0.60	0.50
Thr	355	A	.	.	B	.	.	.	0.43	1.40	.	*	.	0.60	0.24
Met	356	A	.	.	B	.	.	.	0.72	0.91	*	.	.	0.60	0.59
Leu	357	A	.	.	B	.	.	.	1.27	1.14	*	.	.	0.60	0.40
Ile	358	A	.	.	B	.	.	.	0.46	1.03	*	*	.	0.60	0.20
Lys	359	A	.	.	B	.	.	.	0.17	0.94	*	*	.	0.60	0.33
Trp	360	A	.	.	B	.	.	.	0.17	0.33	*	*	.	0.00	0.81
Val	361	A	.	.	B	.	.	.	0.09	0.13	*	*	.	0.45	1.66
Asn	362	.	.	.	.	.	T	C	1.01	0.13	*	.	F	1.95	0.82
Lys	363	.	.	.	.	.	T	C	1.90	0.13	*	*	F	2.40	1.53
Thr	364	.	.	.	.	.	T	C	1.27	1.04	*	.	F	3.00	3.44
Gly	365	.	.	.	.	.	T	C	1.26	1.19	*	.	F	2.70	2.16
Arg	366	.	A	.	.	T	.	.	1.26	1.20	*	.	F	2.20	1.45
Asp	367	.	A	.	.	.	.	C	1.22	0.56	*	.	F	1.55	0.75
Ala	368	A	A	.	.	.	.	.	0.87	0.54	.	.	F	1.20	1.03
Ser	369	A	A	.	.	.	.	.	0.37	0.49	.	.	.	0.30	0.76
Val	370	A	A	.	.	.	.	.	0.10	0.20	.	*	.	0.30	0.37
His	371	A	A	.	.	.	.	.	0.21	0.89	.	*	.	0.60	0.30
Thr	372	A	A	.	.	.	.	.	0.80	0.39	*	*	.	0.30	0.38
Leu	373	A	A	.	.	.	.	.	1.02	0.50	*	*	.	0.60	0.52
Leu	374	A	A	.	.	.	.	.	0.72	0.54	*	.	.	0.60	0.31
Asp	375	A	A	.	.	.	.	.	0.18	0.04	*	.	.	0.30	0.38
Ala	376	A	A	.	.	.	.	.	0.96	0.04	*	.	.	0.30	0.66
Leu	377	A	A	.	.	.	.	.	0.99	0.04	*	.	.	0.30	0.66
Glu	378	A	A	.	.	.	.	.	0.18	0.21	*	.	.	0.30	0.39
Thr	379	A	A	.	.	.	.	.	0.74	0.21	*	*	F	0.45	0.67
Leu	380	A	A	.	.	.	.	.	0.07	0.71	*	.	F	0.90	1.59
Gly	381	A	A	.	.	.	.	.	0.07	0.71	*	.	F	0.75	0.76
Glu	382	A	A	.	.	.	.	.	0.79	0.21	*	.	F	0.45	0.53
Arg	383	A	A	.	.	.	.	.	0.79	0.70	*	.	F	0.90	1.28
Leu	384	A	A	.	.	.	.	.	1.14	0.99	*	*	F	0.90	2.24
Ala	385	A	A	.	.	.	.	.	1.07	1.41	*	*	F	0.90	2.59
Lys	386	A	A	.	.	.	.	.	1.41	0.73	*	.	F	0.75	0.93
Gln	387	A	A	.	.	.	.	.	1.41	0.73	*	*	F	0.90	1.95
Lys	388	A	A	.	.	.	.	.	1.27	1.41	*	*	F	0.90	3.22
Ile	389	A	A	.	.	.	.	.	1.27	1.41	.	*	F	0.90	2.19
Glu	390	A	A	.	.	.	.	.	1.04	0.73	*	*	F	0.90	1.04
Asp	391	A	A	.	.	.	.	.	0.70	0.44	.	*	F	0.45	0.43
His	392	A	A	.	.	.	.	.	0.40	0.06	*	*	.	0.30	0.82
Leu	393	A	A	.	.	.	.	.	0.01	0.36	*	*	.	0.30	0.64
Leu	394	A	A	.	.	.	.	.	0.94	0.07	*	*	F	0.15	0.38
Ser	395	A	.	.	.	.	T	.	0.24	0.07	*	*	F	0.25	0.55
Ser	396	A	.	.	.	.	T	.	0.36	0.36	*	*	F	0.25	0.58
Gly	397	.	.	.	.	T	T	.	0.57	0.29	.	.	F	0.65	0.70
Lys	398	A	.	.	.	.	T	.	0.57	0.36	.	.	F	0.25	0.82
Phe	399	A	A	.	.	.	.	.	0.24	0.66	.	.	.	0.60	0.50
Met	400	.	A	B	.	.	.	.	0.20	0.27	.	*	.	0.30	0.88
Tyr	401	.	A	B	.	.	.	.	0.50	0.27	.	*	.	0.30	0.44
Leu	402	A	A	.	.	.	.	.	0.26	0.67	.	*	.	0.60	0.81
Glu	403	A	A	.	.	.	.	.	0.21	0.39	.	*	.	0.30	0.82
Gly	404	A	.	.	.	.	.	.	0.61	0.23	.	*	F	0.65	0.88
Asn	405	A	.	.	.	.	T	.	0.62	0.60	.	*	F	1.30	1.43
Ala	406	A	.	.	.	.	T	.	0.27	0.79	.	*	F	1.15	0.83
Asp	407	A	.	.	.	.	T	.	0.78	0.17	.	*	F	0.85	0.83
Ser	408	A	.	.	.	.	T	.	0.39	0.21	.	*	F	0.85	0.69
Ala	409	A	.	.	.	.	.	.	0.34	0.19	.	*	.	0.50	0.88
Met	410	A	.	.	.	.	.	.	0.04	0.26	.	.	.	0.50	0.67
Ser	411	A	.	.	.	.	.	.	0.16	0.17	.	.	.	0.10	0.64

[0066] Among highly preferred fragments in this regard are those that comprise, or alternatively consist of, regions of DR5 that combine several structural features, such as several of the features set out above. Preferred nucleic acid fragments of the present invention further include nucleic acid molecules encoding a polypeptide comprising, or alternatively consisting of, one, two, three, four, five, or more epitope-bearing portions of the DR5 protein. In particular, such nucleic acid fragments of the present invention include, but are not limited to, nucleic acid molecules encoding a polypeptide comprising, or alternatively consisting of, one, two, three, or more amino acid sequences selected from the group consisting of: amino acid residues from about 62 to about 110 in FIG. 1 (amino acid residues from about 11 to about 59 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, amino acid residues from about 119 to about 164 in FIG. 1 (amino acid residues from about 68 to about 113 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, amino acid residues from about 224 to about 271 in FIG. 1 (amino acid residues from about 173 to about 220 in SEQ ID NO:2); and a polypeptide comprising, or alternatively consisting of, amino acid residues from about 275 to about 370 in FIG. 1 (amino acid residues from about 224 to about 319 in SEQ ID NO:2). The inventors have determined that the above polypeptide fragments are antigenic regions of the DR5 protein. Methods for determining other such epitope-bearing portions of the DR5 protein are described in detail below. In this context about includes the particularly recited value and values larger or smaller by several (5, 4, 3, 2, or 1) amino acid residues. Polypeptides encoded by these nucleic acids are also encompassed by the invention.

[0067] Further, the invention includes a polynucleotide comprising, or alternatively consisting of, any portion of at least about 30 nucleotides, preferably at least about 50 nucleotides, of SEQ ID NO:1 from residue 283 to 1,362, preferably from 283 to 681. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0068] In specific embodiments, the polynucleotides of the invention are less than 100000 kb, 50000 kb, 10000 kb, 1000 kb, 500 kb, 400 kb, 350 kb, 300 kb, 250 kb, 200 kb, 175 kb, 150 kb, 125 kb, 100 kb, 75 kb, 50 kb, 40 kb, 30 kb, 25 kb, 20 kb, 15 kb, 10 kb, 7.5 kb, or 5 kb in length.

[0069] In further embodiments, polynucleotides of the invention comprise, or alternatively consisting of, at least 15, at least 30, at least 50, at least 100, or at least 250, at least 500, or at least 1000 contiguous nucleotides of DR5 coding sequence, but consist of less than or equal to 1000 kb, 500 kb, 250 kb, 200 kb, 150 kb, 100 kb, 75 kb, 50 kb, 30 kb, 25 kb, 20 kb, 15 kb, 10 kb, or 5 kb of genomic DNA that flanks the 5 or 3 coding nucleotide set forth in FIG. 1 (SEQ ID NO:1). In further embodiments, polynucleotides of the invention comprise, or alternatively consist of, at least 15, at least 30, at least 50, at least 100, or at least 250, at least 500, or at least 1000 contiguous nucleotides of DR5 coding sequence, but do not comprise, or alternatively consist of, all or a portion of any DR5 intron. In another embodiment, the nucleic acid comprising, or alternatively consisting of, DR5 coding sequence does not contain coding sequences of a genomic flanking gene (i.e., 5 or 3 to the DR5 gene in the genome). In other embodiments, the polynucleotides of the invention do not contain the coding sequence of more than 1000, 500, 250, 100, 50, 25, 20, 15, 10, 5, 4, 3, 2, or 1 genomic flanking gene(s).

[0070] In another embodiment, the invention provides an isolated nucleic acid molecule comprising, or alternatively consisting of, a polynucleotide which hybridizes under stringent hybridization conditions to a portion of the polynucleotide in a nucleic acid molecule of the invention described above, for instance, the sequence complementary to the coding and/or noncoding (i.e., transcribed, untranslated) sequence depicted in SEQ ID NO:1, the cDNA contained in ATCC Deposit No. 97920, and the sequence encoding a DR5 domain, or a polynucleotide fragment as described herein. By stringent hybridization conditions is intended overnight incubation at 42 C. in a solution comprising, or alternatively consisting of: 50% formamide, 5SSC (750 mM NaCl, 75 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5Denhardt's solution, 10% dextran sulfate, and 20 g/ml denatured, sheared salmon sperm DNA, followed by washing the filters in 0.1SSC at about 65 C. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0071] By a polynucleotide which hybridizes to a portion of a polynucleotide is intended a polynucleotide (either DNA or RNA) hybridizing to at least about 15 nucleotides (nt), and more preferably at least about 20 nt, still more preferably at least about 30 nt, and even more preferably about 30-70 or 80-150 nt, or the entire length of the reference polynucleotide. By a portion of a polynucleotide of at least about 20 nt in length, for example, is intended 20 or more contiguous nucleotides from the nucleotide sequence of the reference polynucleotide (e.g., the deposited cDNA or the nucleotide sequence as shown in SEQ ID NO:1). In this context about includes the particularly recited size, larger or smaller by several (5, 4, 3, 2, or 1) nucleotides, at either terminus or at both termini. These have uses, which include, but are not limited to, as diagnostic probes and primers as discussed above and in more detail below.

[0072] Of course, a polynucleotide which hybridizes only to a poly A sequence (such as the 3 terminal poly(A) tract of the DR5 cDNA shown in FIG. 1 (SEQ ID NO:1)), or to a complementary stretch of T (or U) resides, would not be included in a polynucleotide of the invention used to hybridize to a portion of a nucleic acid of the invention, since such a polynucleotide would hybridize to any nucleic acid molecule containing a poly (A) stretch or the complement thereof (e.g., practically any double-stranded cDNA generated from an oligo-dT primed cDNA library).

[0073] As indicated, nucleic acid molecules of the present invention which encode a DR5 polypeptide may include, but are not limited to, the coding sequence for the mature polypeptide, by itself; the coding sequence for the mature polypeptide and additional sequences, such as those encoding a leader or secretory sequence, such as a pre-, pro- or prepro-protein sequence; the coding sequence of the mature polypeptide, with or without the aforementioned additional coding sequences, together with additional, non-coding sequences, including for example, but not limited to introns and non-coding 5 and 3 sequences, such as the transcribed, non-translated sequences that play a role in transcription, mRNA processingincluding splicing and polyadenylation signals, for exampleribosome binding and stability of mRNA; additional coding sequence which codes for additional amino acids, such as those which provide additional functionalities. Thus, for instance, the polypeptide may be fused to a marker sequence, such as a peptide, which facilitates purification of the fused polypeptide. In certain preferred embodiments of this aspect of the invention, the marker sequence is a hexa-histidine peptide, such as the tag provided in a pQE vector (Qiagen, Inc.), among others, many of which are commercially available. As described in Gentz et al., Proc. Natl. Acad. Sci. USA 86: 821-824 (1989), for instance, hexa-histidine provides for convenient purification of the fusion protein. The HA tag is another peptide useful for purification which corresponds to an epitope derived from the influenza hemagglutinin protein, which has been described by Wilson et al., Cell 37:767-778(1984). As discussed below, other such fusion proteins include the DR5 receptor fused to Fc at the N- or C-terminus.

[0074] The present invention further relates to variants of the nucleic acid molecules of the present invention, which encode portions, analogs, or derivatives of the DR5 receptor. Variants may occur naturally, such as a natural allelic variant. By an allelic variant is intended one of several alternate forms of a gene occupying a given locus on a chromosome of an organism. Genes II, Lewin, B., ed., John Wiley & Sons, New York (1985). Non-naturally occurring variants may be produced using art-known mutagenesis techniques.

[0075] Such variants include those produced by nucleotide substitutions, deletions or additions which may involve one or more nucleotides. The variants may be altered in coding or non-coding regions or both. Alterations in the coding regions may produce conservative or non-conservative amino acid substitutions, deletions or additions. Especially preferred among these are silent substitutions, additions, and deletions, which do not alter the properties and activities of the DR5 receptor or portions thereof Also especially preferred in this regard are conservative substitutions.

[0076] Further embodiments of the invention include isolated nucleic acid molecules that are at least 80% identical, and more preferably at least 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical, to (a) a nucleotide sequence encoding the polypeptide comprising, or alternatively consisting of, the amino acid sequence in SEQ ID NO:2; (b) a nucleotide sequence encoding the polypeptide comprising, or alternatively consisting of, the amino acid sequence in SEQ ID NO:2, but lacking the amino terminal methionine; (c) a nucleotide sequence encoding the polypeptide comprising, or alternatively consisting of, the amino acid sequence at positions from about 1 to about 360 in SEQ ID NO:2; (d) a nucleotide sequence encoding the polypeptide comprising, or alternatively consisting of, the amino acid sequence encoded by the cDNA contained in ATCC Deposit No. 97920; (e) a nucleotide sequence encoding the mature DR5 polypeptide comprising, or alternatively consisting of, the amino acid sequence encoded by the cDNA contained in ATCC Deposit No. 97920; (f) a nucleotide sequence that encodes the DR5 extracellular domain comprising, or alternatively consisting of, the amino acid sequence at positions from about 1 to about 133 in SEQ ID NO:2, or the DR5 extracellular domain encoded by the cDNA contained in ATCC Deposit No. 97920; (g) a nucleotide sequence that encodes the DR5 cysteine rich domain comprising, or alternatively consisting of, the amino acid sequence at positions from about 33 to about 128 in SEQ ID NO:2, or the DR5 cysteine rich domain encoded by the cDNA contained in ATCC Deposit No. 97920; (h) a nucleotide sequence that encodes the DR5 transmembrane domain comprising, or alternatively consisting of, the amino acid sequence at positions from about 134 to about 157 of SEQ ID NO:2, or the DR5 transmembrane domain encoded by the cDNA contained in ATCC Deposit No. 97920; (i) a nucleotide sequence that encodes the DR5 intracellular domain comprising, or alternatively consisting of, the amino acid sequence at positions from about 158 to about 360 of SEQ ID NO:2, or the DR5 intracellular domain encoded by the cDNA contained in ATCC Deposit No. 97920; (j) a nucleotide sequence that encodes the DR5 receptor extracellular and intracellular domains with all or part of the transmembrane domain deleted; (k) a nucleotide sequence that encodes the DR5 death domain comprising, or alternatively consisting of, the amino acid sequence at positions from about 273 to about 340 of SEQ ID NO:2, or the DR5 death domain encoded by the cDNA contained in ATCC Deposit No. 97920; (l) a nucleotide sequence that encodes a fragment of the polypeptide of (c) having DR5 functional activity (e.g., antigenic or biological activity); and (m) a nucleotide sequence complementary to any of the nucleotide sequences in (a), (b), (c), (d), (e), (f), (g), (h), (i), (j), (k), or (l) above. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0077] By a polynucleotide having a nucleotide sequence at least, for example, 95% identical to a reference nucleotide sequence encoding a DR5 polypeptide is intended that the nucleotide sequence of the polynucleotide is identical to the reference sequence except that the polynucleotide sequence may include up to five mismatches per each 100 nucleotides of the reference nucleotide sequence encoding the DR5 polypeptide. In other words, to obtain a polynucleotide having a nucleotide sequence at least 95% identical to a reference nucleotide sequence, up to 5% of the nucleotides in the reference sequence may be deleted or substituted with another nucleotide, or a number of nucleotides up to 5% of the total nucleotides in the reference sequence may be inserted into the reference sequence. The reference (query) sequence may be the entire DR5 nucleotide sequence shown in FIG. 1 (SEQ ID NO:1) or any polynucleotide fragment (e.g., a polynucleotide encoding the amino acid sequence of a DR5 N and/or C terminal deletion described herein) as described herein.

[0078] As a practical matter, whether any particular nucleic acid molecule is at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to, for instance, the nucleotide sequence shown in SEQ ID NO:1 or to the nucleotide sequence of the deposited cDNA can be determined conventionally using known computer programs such as the Bestfit program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, 575 Science Drive, Madison, Wis. 53711). Bestfit uses the local homology algorithm of Smith and Waterman, Advances in Applied Mathematics 2:482-489 (1981), to find the best segment of homology between two sequences. Then using Bestfit or any other sequence alignment program to determine whether a particular sequence is, for instance, 95% identical to a reference sequence according to the present invention, the parameters are set, of course, such that the percentage of identity is calculated over the full length of the reference nucleotide sequence and that gaps in homology of up to 5% of the total number of nucleotides in the reference sequence are allowed.

[0079] In a specific embodiment, the identity between a reference (query) sequence (a sequence of the present invention) and a subject sequence, also referred to as a global sequence alignment, is determined using the FASTDB computer program based on the algorithm of Brutlag et al. (Comp. App. Biosci. 6:237-245 (1990)). Preferred parameters used in a FASTDB alignment of DNA sequences to calculate percent identity are: MatrixUnitary, k-tuple4, Mismatch Penalty1, Joining Penalty30, Randomization Group Length0, Cutoff Score1, Gap Penalty5, Gap Size Penalty 0.05, Window Size500 or the length of the subject nucleotide sequence, whichever is shorter. According to this embodiment, if the subject sequence is shorter than the query sequence because of 5 or 3 deletions, not because of internal deletions, a manual correction is made to the results to take into consideration the fact that the FASTDB program does not account for 5 and 3 truncations of the subject sequence ashen calculating percent identity. For subject sequences truncated at the 5 or 3 ends, relative to the query sequence, the percent identity is corrected by calculating the number of bases of the query sequence that are 5 and 3 of the subject sequence, which are not matched/aligned, as a percent of the total bases of the query sequence. A determination of whether a nucleotide is matched/aligned is determined by results of the FASTDB sequence alignment. This percentage is then subtracted from the percent identity, calculated by the above FASTDB program using the specified parameters, to arrive at a final percent identity score. This corrected score is what is used for the purposes of this embodiment. Only bases outside the 5 and 3 bases of the subject sequence, as displayed by the FASTDB alignment, which are not matched/aligned with the query sequence, are calculated for the purposes of manually adjusting the percent identity score. For example, a 90 base subject sequence is aligned to a 100 base query sequence to determine percent identity. The deletions occur at the 5 end of the subject sequence and therefore, the FASTDB alignment does not show a matched/alignment of the first 10 bases at 5 end. The 10 unpaired bases represent 10% of the sequence (number of bases at the 5 and 3 ends not matched/total number of bases in the query sequence) so 10% is subtracted from the percent identity score calculated by the FASTDB program. If the remaining 90 bases were perfectly matched the final percent identity would be 90%. In another example, a 90 base subject sequence is compared with a 100 base query sequence. This time the deletions are internal deletions so that there are no bases on the 5 or 3 of the subject sequence which are not matched/aligned with the query. In this case the percent identity calculated by FASTDB is not manually corrected. Once again, only bases 5 and 3 of the subject sequence which are not matched/aligned with the query sequence are manually corrected for. No other manual corrections are made for the purposes of this embodiment.

[0080] The present application is directed to nucleic acid molecules at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to the nucleic acid sequence shown in SEQ ID NO:1, the nucleic acid sequence of the deposited cDNAs, or fragments thereof, irrespective of whether they encode a polypeptide having DR5 functional activity. This is because even where a particular nucleic acid molecule does not encode a polypeptide having DR5 functional activity, one of skill in the art would still know how to use the nucleic acid molecule, for instance, as a hybridization probe or a polymerase chain reaction (PCR) primer. Uses of the nucleic acid molecules of the present invention that do not encode a polypeptide having DR5 functional activity include, inter alia: (1) isolating the DR5 gene or allelic variants thereof in a cDNA library; (2) in situ hybridization (e.g., FISH) to metaphase chromosomal spreads to provide precise chromosomal location of the DR5 gene, as described in Verma et al., Human Chromosomes: A Manual of Basic Techniques, Pergamon Press, New York (1988); and (3) Northern Blot analysis for detecting DR5 mRNA expression in specific tissues.

[0081] Preferred, however, are nucleic acid molecules having sequences at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to the nucleic acid sequence shown in SEQ ID NO:1, the nucleic acid sequence of the deposited cDNAs, or fragments thereof, which do, in fact, encode a polypeptide having DR5 protein functional activity. By a polypeptide having DR5 functional activity is intended polypeptides exhibiting activity similar, but not necessarily identical, to a functional activity of the DR5 protein of the invention (either the full-length (i.e., complete) protein or, preferably, the mature protein), as measured in a particular biological assay. For example, DR5 polypeptide functional activity can be measured by the ability of a polypeptide sequence described herein to form multimers (e.g., homodimers and homotrimers) with complete DR5, and to bind a DR5 ligand (e.g., TRAIL). DR5 polypeptide functional activity can be also be measured, for example, by determining the ability of a polypeptide of the invention to induce apoptosis in cells expressing the polypeptide. These functional assays can be routinely performed using techniques described herein and otherwise known in the art.

[0082] For example, DR5 protein functional activity (e.g., biological activity) can be measured using the cell death assays performed essentially as previously described (A. M. Chinnaiyan, et al., Cell 81:505-12 (1995); M. P. Boldin, et al., J Biol Chem 270:7795-8 (1995); F. C. Kischkel, et al., EMBO 14:5579-5588 (1995); A. M. Chinnaiyan, et al., J Biol Chem 271:4961-4965 (1996)) and as set forth in Example 5, below. In MCF7 cells, plasmids encoding full-length DR5 or a candidate death domain containing receptor are co-transfected with the pLantern reporter construct encoding green fluorescent protein. Nuclei of cells transfected with DR5 will exhibit apoptotic morphology as assessed by DAPI staining. Similar to TNFR-1 and Fas/APO-1 (M. Muzio, et al., Cell 85:817-827 (1996); M. P. Boldin, et al., Cell 85:803-815 (1996); M. Tewari, et al., J Biol Chem 270:3255-60 (1995)), DR5-induced apoptosis is preferably blocked by the inhibitors of ICE-like proteases, CrmA and z-VAD-fmk.

[0083] Of course, due to the degeneracy of the genetic code, one of ordinary skill in the art will immediately recognize that a large number of the nucleic acid molecules having a sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to for example, the nucleic acid sequence of the deposited cDNA, the nucleic acid sequence shown in SEQ ID NO:1, or fragments thereof, will encode a polypeptide having DR5 protein functional activity. In fact, since degenerate variants of these nucleotide sequences all encode the same polypeptide, in many instances, this will be clear to the skilled artisan even without performing the above described comparison assay. It will be further recognized in the art that, for such nucleic acid molecules that are not degenerate variants, a reasonable number will also encode a polypeptide having DR5 protein functional activity. This is because the skilled artisan is fully aware of amino acid substitutions that are either less likely or not likely to significantly effect protein function (e.g., replacing one aliphatic amino acid with a second aliphatic amino acid), as further described below.

[0084] For example, guidance concerning how to make phenotypically silent amino acid substitutions is provided in Bowie, J. U. et al., Deciphering the 25 Message in Protein Sequences: Tolerance to Amino Acid Substitutions, Science 247:1306-1310 (1990), wherein the authors indicate that proteins are surprisingly tolerant of amino acid substitutions.

[0085] Polynucleotide Assays

[0086] This invention is also related to the use of the DR5 polynucleotides to detect complementary polynucleotides such as, for example, as a diagnostic reagent. Detection of a mutated form of DR5 associated with a dysfunction will provide a diagnostic tool that can add or define a diagnosis of a disease or susceptibility to a disease which results from under-expression, over-expression, or altered expression of DR5 or a soluble form thereof, such as, for example, tumors or auto immune disease.

[0087] Individuals carrying mutations in the DR5 gene may be detected at the DNA level by a variety of techniques. Nucleic acids for diagnosis may be obtained from a patient's cells, such as from blood, urine, saliva, tissue biopsy and autopsy material. The genomic DNA may be used directly for detection or may be amplified enzymatically by using PCR prior to analysis. (Saiki et al., Nature 324:163-166 (1986)). RNA or cDNA may also be used in the same ways. As an example, PCR primers complementary to the nucleic acid encoding DR5 can be used to identify and analyze DR5 expression and mutations. For example, deletions and insertions can be detected by a change in size of the amplified product in comparison to the normal genotype. Point mutations can be identified by hybridizing amplified DNA to radiolabeled DR5 RNA or alternatively, radiolabeled DR5 antisense DNA sequences. Perfectly matched sequences can be distinguished from mismatched duplexes by RNase A digestion or by differences in melting temperatures.

[0088] Sequence differences between a reference gene and genes having mutations also may be revealed by direct DNA sequencing. In addition, cloned DNA segments may be employed as probes to detect specific DNA segments. The sensitivity of such methods can be greatly enhanced by appropriate use of PCR or another amplification method. For example, a sequencing primer is used with double-stranded PCR product or a single-stranded template molecule generated by a modified PCR. The sequence determination is performed by conventional procedures with radiolabeled nucleotide or by automatic sequencing procedures with fluorescent-tags.

[0089] Genetic testing based on DNA sequence differences may be achieved by detection of alteration in electrophoretic mobility of DNA fragments in gels, with or without denaturing agents. Small sequence deletions and insertions can be visualized by high resolution gel electrophoresis. DNA fragments of different sequences may be distinguished on denaturing formamide gradient gels in which the mobilities of different DNA fragments are retarded in the gel at different positions according to their specific melting or partial melting temperatures (see, e.g., Myers et al., Science 230:1242 (1985)).

[0090] Sequence changes at specific locations also may be revealed by nuclease protection assays, such as RNase and S1 protection or the chemical cleavage method (e.g., Cotton et al., Proc. Natl Acad. Sci. USA 85: 4397-4401 (1985)).

[0091] Thus, the detection of a specific DNA sequence may be achieved by methods which include, but are not limited to, hybridization, RNase protection, chemical cleavage, direct DNA sequencing or the use of restriction enzymes, (e.g., restriction fragment length polymorphisms (RFLP) and Southern blotting of genomic DNA).

[0092] In addition to more conventional gel-electrophoresis and DNA sequencing, mutations also can be detected by in situ analysis.

[0093] Vectors and Host Cells

[0094] The present invention also relates to vectors which include DNA molecules of the present invention, host cells which are genetically engineered with vectors of the invention and the production of polypeptides of the invention by recombinant techniques.

[0095] Host cells can be genetically engineered to incorporate nucleic acid molecules and express polypeptides of the present invention. The polynucleotides may be introduced alone or with other polynucleotides. Such other polynucleotides may be introduced independently, co-introduced or introduced joined to the polynucleotides of the invention.

[0096] In accordance with this aspect of the invention the vector may be, for example, a plasmid vector, a single or double-stranded phage vector, a single or double-stranded RNA or DNA viral vector. Such vectors may be introduced into cells as polynucleotides, preferably DNA, by well known techniques for introducing DNA and RNA into cells. Viral vectors may be replication competent or replication defective. In the latter case viral propagation generally will occur only in complementing host cells.

[0097] Preferred among vectors, in certain respects, are those for expression of polynucleotides and polypeptides of the present invention. Generally, such vectors comprise cis-acting control regions effective for expression in a host operatively linked to the polynucleotide to be expressed. Appropriate trans-acting factors either are supplied by the host, supplied by a complementing vector or supplied by the vector itself upon introduction into the host.

[0098] A great variety of expression vectors can be used to express a polypeptide of the invention. Such vectors include chromosomal, episomal and virus-derived vectors e.g., vectors derived from bacterial plasmids, from bacteriophage, from yeast episomes, from yeast chromosomal elements, from viruses such as baculoviruses, papova viruses, such as SV40, vaccinia viruses, adenoviruses, fowl pox viruses, pseudorabies viruses and retroviruses, and vectors derived from combinations thereof, such as those derived from plasmid and bacteriophage genetic elements, such as cosmids and phagemids, all may be used for expression in accordance with this aspect of the present invention. Generally, any vector suitable to maintain, propagate or express polynucleotides to express a polypeptide in a host may be used for expression in this regard.

[0099] The DNA sequence in the expression vector is operatively linked to appropriate expression control sequence(s)), including, for instance, a promoter to direct mRNA transcription. Representatives of such promoters include the phage lambda PL promoter, the E. coli lac, trp and tac promoters, the SV40 early and late promoters and promoters of retroviral LTRs, to name just a few of the well-known promoters. In general, expression constructs will contain sites for transcription, initiation and termination, and, in the transcribed region, a ribosome binding site for translation. The coding portion of the mature transcripts expressed by the constructs will include a translation initiating AUG at the beginning and a termination codon (UAA, UGA or UAG) appropriately positioned at the end of the polypeptide to be translated.

[0100] In addition, the constructs may contain control regions that regulate as well as engender expression. Generally, such regions will operate by controlling transcription, such as repressor binding sites and enhancers, among others.

[0101] Vectors for propagation and expression generally will include selectable markers. Such markers also may be suitable for amplification or the vectors may contain additional markers for this purpose. In this regard, the expression vectors preferably contain one or more selectable marker genes to provide a phenotypic trait for selection of transformed host cells. Such markers include, but are not limited to, dihydrofolate reductase or neomycin resistance for eukaryotic cell culture, and tetracycline or ampicillin resistance genes for culturing E. coli and other bacteria.

[0102] The vector containing the appropriate DNA sequence as described elsewhere herein, as well as an appropriate promoter, and other appropriate control sequences, may be introduced into an appropriate host using a variety of well known techniques suitable to expression therein of a desired polypeptide. Representative examples of appropriate hosts include bacterial cells, such as E. coli, Streptomyces and Salmonella typhimurium cells; fungal cells, such as yeast cells; insect cells such as Drosophila S2 and Spodoptera Sf9 cells; animal cells such as CHO, COS and Bowes melanoma cells; and plant cells. Appropriate culture mediums and conditions for the above-described host cells are known in the art.

[0103] Among vectors preferred for use in bacteria are pQE70, pQE60 and pQE-9, available from Qiagen; pBS vectors, Phagescript vectors, Bluescript vectors, pNH8A, pNH16a, pNH18A, pNH46A, available from Stratagene; and

[0104] ptrc99a, pKK223-3, pKK233-3, pDR540, pRIT5 available from Pharmacia.

[0105] Among preferred eukaryotic vectors are pWLNEO, pSV2CAT, pOG44, pXT1 and pSG available from Stratagene; and pSVK3, pBPV, pMSG and pSVL available from Pharmacia. These vectors are listed solely by way of illustration of the many commercially available and well known vectors available to those of skill in the art.

[0106] Selection of appropriate vectors and promoters for expression in a host cell is a well known procedure and the requisite techniques for expression vector construction, introduction of the vector into the host and expression in the host are routine skills in the art.

[0107] The present invention also relates to host cells containing the above-described vector constructs described herein, and additionally encompasses host cells containing nucleotide sequences of the invention that are operably associated with one or more heterologous control regions (e.g., promoter and/or enhancer) using techniques known of in the art. The host cell can be a higher eukaryotic cell, such as a mammalian cell (e.g., a human derived cell), or a lower eukaryotic cell, such as a yeast cell, or the host cell can be a prokaryotic cell, such as a bacterial cell. The host strain may be chosen which modulates the expression of the inserted gene sequences, or modifies and processes the gene product in the specific fashion desired. Expression from certain promoters can be elevated in the presence of certain inducers; thus expression of the genetically engineered polypeptide maybe controlled. Furthermore, different host cells have characteristics and specific mechanisms for the translational and post-translational processing and modification (e.g., phosphorylation, cleavage) of proteins. Appropriate cell lines can be chosen to ensure the desired modifications and processing of the foreign protein expressed.

[0108] Introduction of the construct into the host cell can be effected by calcium phosphate transfection, DEAE-dextran mediated transfection, cationic lipid-mediated transfection, electroporation, transduction, infection or other methods. Such methods are described in many standard laboratory manuals, such as Davis et al., Basic Methods in Molecular Biology (1986).

[0109] In addition to encompassing host cells containing the vector constructs discussed herein, the invention also encompasses primary, secondary, and immortalized host cells of vertebrate origin, particularly mammalian origin, that have been engineered to delete or replace endogenous genetic material (e.g., DR5 coding sequence), and/or to include genetic material (e.g., heterologous polynucleotide sequences) that is operably associated with DR5 polynucleotides of the invention, and which activates, alters, and/or amplifies endogenous DR5 polynucleotides. For example, techniques known in the art may be used to operably associate heterologous control regions (e.g., promoter and/or enhancer) and endogenious DR5 polynucleotide sequences via homologous recombination (see, e.g., U.S. Pat. No. 5,641,670, issued Jun. 24, 1997; International Publication Number WO 96/29411, published Sep. 26, 1996; International Publication Number WO 94/12650, published Aug. 4, 1994; Koller et al., Proc. Natl. Acad. Sci. USA 86:8932-8935 (1989); and Zijlstra et al., Nature 342:435-438 (1989), the disclosures of each of which are incorporated by reference in their entireties).

[0110] The polypeptide may be expressed in a modified form, such as a fusion protein (comprising the polypeptide joined via a peptide bond to a heterologous protein sequence (of a different protein)), and may include not only secretion signals but also additional heterologous functional regions. Such a fusion protein can be made by ligating polynucleotides of the invention and the desired nucleic acid sequence encoding the desired amino acid sequence to each other, by methods known in the art, in the proper reading frame, and expressing the fusion protein product by methods known in the art. Alternatively, such a fusion protein can be made by protein synthetic techniques, e.g., by use of a peptide synthesizer. Thus, for instance, a region of additional amino acids, particularly charged amino acids, may be added to the N-terminus of the polypeptide to improve stability and persistence in the host cell, during purification or during subsequent handling and storage. Also, region also may be added to the polypeptide to facilitate purification. Such regions may be removed prior to final preparation of the polypeptide. For example, in one embodiment, polynucleotides encoding DR5 polypeptides of the invention may be fused to the pelB pectate lyase signal sequence to increase the efficiency to expression and purification of such polypeptides in Gram-negative bacteria. See, U.S. Pat. Nos. 5,576,195 and 5,846,818, the contents of which are herein incorporated by reference in their entireties.

[0111] Alternatively, such a fusion protein can be made by protein synthetic techniques, e.g., by use of a peptide synthesizer. Thus, for instance, a region of additional amino acids, particularly charged amino acids, may be added to the N-terminus of the polypeptide to improve stability and persistence in the host cell, during purification or during subsequent handling and storage. Additionally, a region also may be added to the polypeptide to facilitate purification. Such regions may be removed prior to final preparation of the polypeptide. The addition of peptide moieties to polypeptides to engender secretion or excretion, to improve stability and to facilitate purification, among others, are familiar and routine techniques in the art. A preferred fusion protein comprises a heterologous region from immunoglobulin that is useful to solubilize proteins. For example, EP-A-O 464 533 (Canadian counterpart 2045869) discloses fusion proteins comprising various portions of constant region of immunoglobin molecules together with another human protein or part thereof. In many cases, the Fc part in a fusion protein is thoroughly advantageous for use in therapy and diagnosis and thus results, for example, in improved pharmacokinetic properties (EP-A 0232 262). On the other hand, for some uses it would be desirable to be able to delete the Fc part after the fusion protein has been expressed, detected and purified in the advantageous manner described. This is the case when the Fc portion proves to be a hindrance to use in therapy and diagnosis, for example when the fusion protein is to be used as an antigen for immunizations. In drug discovery, for example, human proteins, such as the hIL-5-receptor, have been fused with Fc portions for the purpose of high-throughput screening assays to identify antagonists of hIL-5. See, D. Bennett et al., Journal of Molecular Recognition, 8:52-58 (1995) and K. Johanson et al., The Journal of Biological Chemistry, 270:9459-9471 (1995).

[0112] Polypeptides of the present invention include naturally purified products, products of chemical synthetic procedures, and products produced by recombinant techniques from a prokaryotic or eukaryotic host, including, for example, bacterial, yeast, higher plant, insect and mammalian cells. Depending upon the host employed in a recombinant production procedure, the polypeptides of the present invention may be glycosylated or may be non-glycosylated. In addition, polypeptides of the invention may also include an initial modified methioninie residue, in some cases as a result of host-mediated processes.

[0113] Transgenics and Knock-Outs

[0114] The DR5 polypeptides of the invention can also be expressed in transgenic animals. Animals of any species, including, but not limited to, mice, rats, rabbits, hamsters, guinea pigs, pigs, micro-pigs, goats, sheep, cows and non-human primates, e.g., baboons, monkeys, and chimpanzees may be used to generate transgenic animals. In a specific embodiment, techniques described herein or otherwise known in the art, are used to express polypeptides of the invention in humans, as part of a gene therapy protocol.

[0115] Any technique known in the art may be used to introduce the transgene (i.e., nucleic acids of the invention) into animals to produce the founder lines of transgenic animals. Such techniques include, but are not limited to, pronuclear microinjection (Paterson et al., Appl. Microbiol. Biotechnol. 40:691-698 (1994), Carver et al., Biotechnology (NY) 11:1263-1270 (1993); Wright et al., Biotechnology (NY) 9:830-834 (1991); and Hoppe et al., U.S. Pat. No. 4,873,191 (1989)); retrovirus mediated gene transfer into germ lines (Van der Putten et al., Proc. Natl. Acad. Sci., USA 82:6148-6152 (1985)), blastocysts or embryos; gene targeting in embryonic stem cells (Thompson et al., Cell 56:313-321 (1989)); electroporation of cells or embryos (Lo, Mol Cell. Biol. 3:1803-1814 (1983)); introduction of the polynucleotides of the invention using a gene gun (see, e.g., Ulmer et al., Science 259:1745 (1993); introducing nucleic acid constructs into embryonic pleuripotent stem cells and transferring the stem cells back into the blastocyst; and sperm-mediated gene transfer (Lavitrano et al., Cell 57:717-723 (1989); etc. For a review of such techniques, see Gordon, Transgenic Animals, Intl. Rev. Cytol. 115:171-229 (1989), which is incorporated by reference herein in its entirety. See also, U.S. Pat. No. 5,464,764 (Capecchi, et al., Positive-Negative Selection Methods and Vectors); U.S. Pat. No. 5,631,153 (Capecchi, et al., Cells and Non-Human Organisms Containing Predetermined Genomic Modifications and Positive-Negative Selection Methods and Vectors for Making Same); U.S. Pat. No. 4,736,866 (Leder, et al., Transgenic Non-Human Animals); and U. S. Pat. No. 4,873,191 (Wagner, et al., Genetic Transformation of Zygotes); each of which is hereby incorporated by reference in its entirety. Further, the contents of each of the documents recited in this paragraph is herein incorporated by reference in its entirety.

[0116] Any technique known in the art may be used to produce transgenic clones containing polynucleotides of the invention, for example, nuclear transfer into enucleated oocytes of nuclei from cultured embryonic, fetal, or adult cells induced to quiescence (Campell et. al, Nature 380:64-66 (1996); Wilmut et al., Nature 385:810-813 (1997)), each of which is herein incorporated by reference in its entirety).

[0117] The present invention provides for transgenic animals that carry the transgene in all their cells, as well as animals which carry the transgene in some, but not all their cells, i.e., mosaic animals or chimeric animals. The transgene may be integrated as a single transgene or as multiple copies such as in concatamers, e.g., head-to-head tandems or head-to-tail tandems. The transgene may also be selectively introduced into and activated in a particular cell type by following, for example, the teaching of Lasko et al. (Proc. Natl. Acad. Sci. USA 89:6232-6236 (1992)). The regulatory sequences required for such a cell-type specific activation will depend upon the particular cell type of interest, and will be apparent to those of skill in the art. When it is desired that the polynucleotide transgene be integrated into the chromosomal site of the endogenous gene, gene targeting is preferred. Briefly, when such a technique is to be utilized, vectors containing some nucleotide sequences homologous to the endogenous gene are designed for the purpose of integrating, via homologous recombination with chromosomal sequences, into and disrupting the function of the nucleotide sequence of the endogenous gene. The transgene may also be selectively introduced into a particular cell type, thus inactivating the endogenous gene in only that cell type, by following, for example, the teaching of Gu et al. (Science 265:103-106 (1994)). The regulatory sequences required for such a cell-type specific inactivation will depend upon the particular cell type of interest, and will be apparent to those of skill in the art. The contents of each of the documents recited in this paragraph is herein incorporated by reference in its entirety.

[0118] Once transgenic animals have been generated, the expression of the recombinant gene may be assayed utilizing standard techniques. Initial screening may be accomplished by Southern blot analysis or PCR techniques to analyze animal tissues to verify that integration of the transgene has taken place. The level of mRNA expression of the transgene in the tissues of the transgenic animals may also be assessed using techniques which include, but are not limited to, Northern blot analysis of tissue samples obtained from the animal, in situ hybridization analysis, and reverse transcriptase-PCR (rt-PCR). Samples of transgenic gene-expressing tissue may also be evaluated immunocytochemically or immunohistochemically using antibodies specific for the transgene product.

[0119] Once the founder animals are produced, they may be bred, inbred, outbred, or crossbred to produce colonies of the particular animal. Examples of such breeding strategies include, but are not limited to: outbreeding of founder animals with more than one integration site in order to establish separate lines; inbreeding of separate lines in order to produce compound transgenics that express the transgene at higher levels because of the effects of additive expression of each transgene; crossing of heterozygous transgenic animals to produce animals homozygous for a given integration site in order to both augment expression and eliminate the need for screening of animals by DNA analysis; crossing of separate homozygous lines to produce compound heterozygous or homozygous lines; and breeding to place the transgene on a distinct background that is appropriate for an experimental model of interest.

[0120] Transgenic and knock-out animals of the invention have uses which include, but are not limited to, animal model systems useful in elaborating the biological function of DR5 polypeptides, studying conditions and/or disorders associated with aberrant DR5 expression, and in screening for compounds effective in ameliorating such conditions and/or disorders.

[0121] In further embodiments of the invention, cells that are genetically engineered to express the proteins of the invention, or alternatively, that are genetically engineered not to express the proteins of the invention (e.g., knockouts) are administered to a patient in vivo. Such cells may be obtained from the patient (i.e., animal, including human) or an MHC compatible donor and can include, but are not limited to fibroblasts, bone marrow cells, blood cells (e.g., lymphocytes), adipocytes, muscle cells, endothelial cells, etc. The cells are genetically engineered in vitro using recombinant DNA techniques to introduce the coding sequence of polypeptides of the invention into the cells, or alternatively, to disrupt the coding sequence and/or endogenous regulatory sequence associated with the polypeptides of the invention, e.g., by transduction (using viral vectors, and preferably vectors that integrate the transgene into the cell genome) or transfection procedures, including, but not limited to, the use of plasmids, cosmids, YACs, naked DNA, electroporation, liposomes, etc. The coding sequence of the polypeptides of the invention can be placed under the control of a strong constitutive or inducible promoter or promoter/enhancer to achieve expression, and preferably secretion, of the polypeptides of the invention. The engineered cells which express and preferably secrete the polypeptides of the invention can be introduced into the patient systemically, e.g., in the circulation, or intraperitoneally. Alternatively, the cells can be incorporated into a matrix and implanted in the body, e.g., genetically engineered fibroblasts can be implanted as part of a skin graft; genetically engineered endothelial cells can be implanted as part of a lymphatic or vascular graft. (See, for example, Anderson et al. U.S. Pat. No. 5,399,349; and Mulligan & Wilson, U.S. Pat. No. 5,460,959, each of which is incorporated by reference herein in its entirety).

[0122] When the cells to be administered are non-autologous or non-MHC compatible cells, they can be administered using well known techniques which prevent the development of a host immune response against the introduced cells. For example, the cells may be introduced in an encapsulated form which, while allowing for an exchange of components with the immediate extracellular environment, does not allow the introduced cells to be recognized by the host immune system.

[0123] DR5 Proteins and Fragments

[0124] The invention further provides for the proteins containing polypeptide sequences encoded by the polynucleotides of the invention.

[0125] The DR5 proteins of the invention may be in monomers or multimers (i.e., dimers, trimers, tetramers, and higher multimers). Accordingly, the present invention relates to monomers and multimers of the DR5 proteins of the invention, their preparation, and compositions (preferably, pharmaceutical compositions) containing them. In specific embodiments, the polypeptides of the invention are monomers, dimers, trimers or tetramers. In additional embodiments, the multimers of the invention are at least dimers, at least trimers, or at least tetramers.

[0126] Multimers encompassed by the invention may be homomers or heteromers. As used herein, the term homomer, refers to a multimer containing only DR5 proteins of the invention (including DR5 fragments, variants, and fusion proteins, as described herein). These homomers may contain DR5 proteins having identical or different polypeptide sequences. In a specific embodiment, a homomer of the invention is a multimer containing only DR5 proteins having an identical polypeptide sequence. In another specific embodiment, a homomer of the invention is a multimer containing DR5 proteins having different polypeptide sequences. In specific embodiments, the multimer of the invention is a homodimer (e.g., containing DR5 proteins having identical or different polypeptide sequences) or a homotrimer (e.g., containing DR5 proteins having identical or different polypeptide sequences). In additional embodiments, the homomeric multimer of the invention is at least a homodimer, at least a homotrimer, or at least a homotetramer.

[0127] As used herein, the term heteromer refers to a multimer containing heterologous proteins (i.e., proteins containing only polypeptide sequences that do not correspond to a polypeptide sequences encoded by the DR5 gene) in addition to the DR5 proteins of the invention. In a specific embodiment, the multimer of the invention is a heterodimer, a heterotrimer, or a heterotetramer. In additional embodiments, the heteromeric multimer of the invention is at least a heterodimer, at least a heterotrimer, or at least a heterotetramer.

[0128] Multimers of the invention may be the result of hydrophobic, hydrophilic, ionic and/or covalent associations and/or may be indirectly linked, by for example, liposome formation. Thus, in one embodiment, multimers of the invention, such as, for example, homodimers or homotrimers, are formed when proteins of the invention contact one another in solution. In another embodiment, heteromultimers of the invention, such as, for example, heterotrimers or heterotetramers, are formed when proteins of the invention contact antibodies to the polypeptides of the invention (including antibodies to the heterologous polypeptide sequence in a fusion protein of the invention) in solution. In other embodiments, multimers of the invention are formed by covalent associations with and/or between the DR5 proteins of the invention. Such covalent associations may involve one or more amino acid residues contained in the polypeptide sequence of the protein (e.g., the polypeptide sequence recited in SEQ ID NO:2 or the polypeptide encoded by the deposited cDNA). In one instance, the covalent associations are cross-linking between cysteine residues located within the polypeptide sequences of the proteins which interact in the native (i.e., naturally occurring) polypeptide. In another instance, the covalent associations are the consequence of chemical or recombinant manipulation. Alternatively, such covalent associations may involve one or more amino acid residues contained in the heterologous polypeptide sequence in a DR5 fusion protein. In one example, covalent associations are between the heterologous sequence contained in a fusion protein of the invention (see, e.g., U.S. Pat. No. 5,478,925). In a specific example, the covalent associations are between the heterologous sequence contained in a DR5-Fc fusion protein of the invention (as described herein). In another specific example, covalent associations of fusion proteins of the invention are between heterologous polypeptide sequences from another TNF family ligand/receptor member that is capable of forming covalently associated multimers, such as for example, oseteoprotegerin (see, e.g., International Publication No. WO 98/49305, the contents of which are herein incorporated by reference in its entirety). In another embodiment, two or more DR5 polypeptides of the invention are joined through synthetic linkers (e.g., peptide, carbohydrate or soluble polymer linkers). Examples include, but are not limited to, those peptide linkers described in U.S. Pat. No. 5,073,627 (hereby incorporated by reference). Proteins comprising multiple DR5 polypeptides separated by peptide linkers may be produced using conventional recombinant DNA technology.

[0129] Another method for preparing multimer DR5 polypeptides of the invention involves use of DR5 polypeptides fused to a leucine zipper or isoleucine zipper polypeptide sequence. Leucine zipper domains and isoleucine zipper domains are polypeptides that promote multimerization of the proteins in which they are found. Leucine zippers were originally identified in several DNA-binding proteins (Landschulz et al., Science 240:1759, (1988)), and have since been found in a variety of different proteins. Among the known leucine zippers are naturally occurring peptides and derivatives thereof that dimerize or trimerize. Examples of leucine zipper domains suitable for producing soluble multimeric DR5 proteins are those described in PCT application WO 94/10308, hereby incorporated by reference. Recombinant fusion proteins comprising a soluble DR5 polypeptide fused to a peptide that dimerizes or trimerizes in solution are expressed in suitable host cells, and the resulting soluble multimeric DR5 is recovered from the culture supernatant using techniques known in the art.

[0130] Certain members of the TNF family of proteins are believed to exist in trimeric form (Beutler and Huffel, Science 264:667, 1994; Banner et al., Cell 73:431 (1993)). Thus, trimeric DR5 may offer the advantage of enhanced biological activity. Preferred leucine zipper moieties are those that preferentially form trimers. One example is a leucine zipper derived from lung surfactant protein D (SPD), as described in Hoppe et al. (FEBS Letters 344:191, (1994)) and in U.S. patent application Ser. No. 08/446,922, hereby incorporated by reference. Other peptides derived from naturally occurring trimeric proteins may be employed in preparing trimeric DR5.

[0131] In another example, proteins of the invention are associated by interactions between Flag polypeptide sequence contained in Flag-DR5 or Flag-DR5 fusion proteins of the invention. In a further embodiment, associations proteins of the invention are associated by interactions between heterologous polypeptide sequence contained in FlagR-DR5 or Flag-DR5 fusion proteins of the invention and anti-Flag antibody.

[0132] The multimers of the invention may be generated using chemical techniques known in the art. For example, proteins desired to be contained in the multimers of the invention may be chemically cross-linked using linker molecules and linker molecule length optimization techniques known in the art (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety). Additionally, multimers of the invention may be generated using techniques known in the art to form one or more inter-molecule cross-links between the cysteine residues located within the polypeptide sequence of the proteins desired to be contained in the multimer (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety).

[0133] Further, proteins of the invention may be routinely modified by the addition of cysteine or biotin to the C-terminus or N-terminus of the polypeptide sequence of the protein and techniques known in the art may be applied to generate multimers containing one or more of these modified proteins (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety). Additionally, techniques known in the art may be applied to generate liposomes containing the protein components desired to be contained in the multimer of the invention (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety).

[0134] Alternatively, multimers of the invention may be generated using genetic engineering techniques known in the art. In one embodiment, proteins contained in multimers of the invention are produced recombinantly using fusion protein technology described herein or otherwise known in the art (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety). In a specific embodiment, polynucleotides coding for a homodimer of the invention are generated by ligating a polynucleotide sequence encoding a polypeptide of the invention to a sequence encoding a linker polypeptide and then further to a synthetic polynucleotide encoding the translated product of the polypeptide in the reverse orientation from the original C-terminus to the N-terminus (lacking the leader sequence) (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety). In another embodiment, recombinant techniques described herein or otherwise known in the art are applied to generate recombinant polypeptides of the invention which contain a transmembrane domain and which can be incorporated by membrane reconstitution techniques into liposomes (see, e.g., U.S. Pat. No. 5,478,925, which is herein incorporated by reference in its entirety).

[0135] The polypeptides of the present invention are preferably provided in an isolated form. By isolated polypeptide is intended a polypeptide removed from its native environment. Thus, a polypeptide produced and/or contained within a recombinant host cell is considered isolated for purposes of the present invention. Also intended as an isolated polypeptide are polypeptides that have been purified, partially or substantially, from a recombinant host cell. For example, a recombinantly produced version of the DR5 polypeptide can be substantially purified by the one-step method described in Smith and Johnson, Gene 67:31-40 (1988).

[0136] In one embodiment, the invention provides an isolated DR5 polypeptide having the amino acid sequence encoded by the deposited cDNA, or the amino acid sequence in SEQ ID NO:2, or a polypeptide or peptide comprising, or alternatively consisting of, a portion (i.e., fragment) of the above polypeptides. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0137] Polypeptide fragments of the present invention include polypeptides comprising, or alternatively consisting of, an amino acid sequence contained in SEQ ID NO:2, encoded by the cDNA contained in the deposited plasmid, or encoded by nucleic acids which hybridize (e.g., under stringent hybridization conditions) to the nucleotide sequence contained in the deposited plasmid, or shown in FIG. 1 (SEQ ID NO:1) or the complementary strand thereto. Protein fragments may be free-standing, or comprised within a larger polypeptide of which the fragment forms a part or region, most preferably as a single continuous region. Representative examples of polypeptide fragments of the invention, include, for example, fragments that comprise, or alternatively consist of, a member selected from the group consisting of from about amino acid residues 51 to 1, 1 to 27, 28 to 40, 41 to 60, 61 to 83, 84 to 100, 101 to 127, 128 to 133, 134 to 157, 158 to 167, 168 to 180, 181 to 200, 201 to 220, 221 to 240, 241 to 260, 261 to 272, 273 to 310, 311 to 340, and 341 to 360 of SEQ ID NO:2, as well as isolated polynucleotides which encode these polypeptides. Additional representative examples of polypeptide fragments of the invention, include, for example, fragments that comprise, or alternatively consist of, a member selected from the group consisting of from about amino acid residues 1-60, 11-70, 21-80, 31-90, 41-100, 51-110, 61-120, 71-130, 81-140, 91-150, 101-160, 111-170, 121-180, 131-190, 141-200, 151-210, 161-220, 171-230, 181-240, 191-250, 201-260, 211-270, 221-280, 231-290, 241-300, 251-310, 261-320, 271-330, 281-340, 291-350, and 301-360 of SEQ ID NO:2, as well as isolated polynucleotides which encode these polypeptides.

[0138] Moreover, polypeptide fragments can be at least about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, or 150 amino acids in length. In this context about includes the particularly recited value, larger or smaller by several (5, 4, 3, 2, or 1) amino acids, at either extreme or at both extremes. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0139] Preferred polypeptide fragments of the present invention include a polypeptide comprising, or alternatively consisting of, one, two, three, four, five or more amino acid sequences selected from the group consisting of a polypeptide comprising, or alternatively consisting of, the DR5 receptor extracellular domain (predicted to constitute amino acid residues from about 1 to about 133 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, the DR5 cysteine rich domain (predicted to constitute amino acid residues from about 33 to about 128 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, the DR5 receptor transmembrane domain (predicted to constitute amino acid residues from about 134 to about 157 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, fragment of the predicted mature DR5 polypeptide, wherein the fragment has a DR5 functional activity (e.g., antigenic activity or biological activity); a polypeptide comprising, or alternatively consisting of, the DR5 receptor intracellular domain (predicted to constitute amino acid residues from about 158 to about 360 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, the DR5 receptor extracellular and intracellular domains with all or part of the transmembrane domain deleted; a polypeptide comprising, or alternatively consisting of, the DR5 receptor death domain (predicted to constitute amino acid residues from about 273 to about 340 in SEQ ID NO:2); and a polypeptide comprising, or alternatively consisting of, one, two, three, four or more epitope bearing portions of the DR5 receptor protein. In additional embodiments, the polypeptide fragments of the invention comprise, or alternatively consist of, any combination of 1, 2, 3, 4, 5, 6, 7, or all 8 of the above members. As above, with the leader sequence, the amino acid residues constituting the DR5 receptor extracellular, transmembrane and intracellular domains have been predicted by computer analysis. Thus, as one of ordinary skill would appreciate, the amino acid residues constituting these domains may vary slightly (e.g., by about 1 to about 15 amino acid residues) depending on the criteria used to define each domain. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0140] As discussed above, it is believed that one or both of the extracellular cysteine-rich motifs of DR5 is important for interactions between DR5 and its ligands. Accordingly, in preferred embodiments, polypeptide fragments of the invention comprise, or alternatively consist of, amino acid residues 33 to 80, and/or 81 to 128 of SEQ ID NO:2. In a specific embodiment the polypeptides of the invention comprise, or alternatively consist of, both of the extracellular cysteine-rich motifs disclosed in SEQ ID NO:2. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0141] Among the especially preferred fragments of the invention are fragments comprising, or alternatively consisting of, structural or functional attributes of DR5. Such fragments include amino acid residues that comprise, or alternatively consisting of, one, two, three, four or more of the following functional domains:

[0142] alpha-helix and alpha-helix forming regions (alpha-regions), beta-sheet and beta-sheet-forming regions (beta-regions), turn and turn-forming regions (turn-regions), coil and coil-forming regions (coil-regions), hydrophillic regions, hydrophobic regions, alpha amphipathic regions, beta amphipathic regions, surface forming regions, and high antigenic index regions (i.e., regions of polypeptides consisting of amino acid residues having an antigenic index of or equal to greater than 1.5, as identified using the default parameters of the Jameson-Wolf program) of DR5.

[0143] Certain preferred regions are those disclosed in FIG. 3 and Table I and include, but are not limited to, regions of the aforementioned types identified by analysis of the amino acid sequence depicted in FIG. 1, such preferred regions include; Garnier-Robson predicted alpha-regions, beta-regions, turn-regions, and coil-regions; Chou-Fasman predicted alpha-regions, beta-regions, and turn-regions; Kyte-Doolittle predicted hydrophilic regions and Hopp-Woods predicted hydrophobic regions; Eisenberg alpha and beta amphipathic regions; Emini surface-forming regions; and Jameson-Wolf high antigenic index regions, as predicted using the default parameters of these computer programs. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0144] In another aspect, the invention provides a peptide or polypeptide comprising, or alternatively consisting of, one, two, three, four, five or more epitope-bearing portions of a polypeptide of the invention. The epitope of this polypeptide portion is an immunogenic or antigenic epitope of a polypeptide described herein. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0145] As to the selection of peptides or polypeptides bearing an antigenic epitope (i.e., that contain a region of a protein molecule to which an antibody can bind), it is well known in that art that relatively short synthetic peptides that mimic part of a protein sequence are routinely capable of eliciting an antiserum that reacts with the partially mimicked protein. See, for instance, J. G. Sutcliffe et al., Antibodies That React With Predetermined Sites on Proteins, Science 219:660-666 (1983). Peptides capable of eliciting protein-reactive sera are frequently represented in the primary sequence of a protein, can be characterized by a set of simple chemical rules, and are confined neither to immunodominant regions of intact proteins (i.e., immunogenic epitopes) nor to the amino or carboxyl terminals.

[0146] Antigenic epitope-bearing peptides and polypeptides of the invention are therefore useful to raise antibodies, including monoclonal antibodies, that bind specifically to a polypeptide of the invention. See, for instance, Wilson et al., Cell 37:767-778 (1984) at 777. Antigenic epitope-bearing peptides and polypeptides of the invention preferably contain a sequence of at least seven, more preferably at least nine and most preferably between at least about 15 to about 30 amino acids contained within the amino acid sequence of a polypeptide of the invention. In the present invention, antigenic epitopes preferably contain a sequence of at least 4, at least 5, at least 6, at least 7, more preferably at least 8, at least 9, at least 10, at least 15, at least 20, at least 25, and, most preferably, between about 15 to about 30 amino acids. Preferred polypeptides comprising, or alternatively consisting of, immunogenic or antigenic epitopes are at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 amino acid residues in length. Polynucleotides encoding these polypeptides are also encompassed by the invention

[0147] Antigenic epitopes are useful, for example, to raise antibodies, including monoclonal antibodies, that specifically bind the epitope. Further, antigenic epitopes can be used as the target molecules in immunoassays. (See, for instance, Wilson et al., Cell 37:767-778 (1984); Sutcliffe et al. Science 219:660-666 (1983)).

[0148] Non-limiting examples of antigenic polypeptides or peptides that can be used to generate DR5 receptor-specific antibodies include: a polypeptide comprising, or alternatively consisting of, amino acid residues from about 11 to about 59 in SEQ ID NO:2, from about 68 to about 113 in SEQ ID NO:2, from about 173 to about 220 in SEQ ID NO:2, and from about 224 to about 319 in SEQ ID NO:2. In this context about includes the particularly recited ranges, larger or smaller by several (5, 4, 3, 2, or 1) amino acid residues, at either terminus or at both termini. As indicated above, the inventors have determined that the above polypeptide fragments are antigenic regions of the DR5 receptor protein. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0149] The epitope-bearing peptides and polypeptides of the invention may be produced by any conventional means. R. A. Houghten, General Method for the Rapid Solid-Phase Synthesis of Large Numbers of Peptides: Specificity of Antigen-Antibody Interaction at the Level of Individual Amino Acids, Proc. Natl. Acad. Sci. USA 82:5131-5135 (1985). This Simultaneous Multiple Peptide Synthesis (SMPS) process is further described in U.S. Pat. No. 4,631,211 to Houghten et al. (1986).

[0150] Immunogenic epitopes can be used, for example, to induce antibodies according to methods well known in the art. (See, for instance, Sutcliffe et al., supra; Wilson et al., supra; Chow et al., Proc. Natl. Acad. Sci. USA 82:910-914; and Bittle et al., J. Gen. Virol. 66:2347-2354 (1985). A preferred immunogenic epitope includes the secreted protein. The polypeptides comprising one or more immunogenic epitopes may be presented for eliciting an antibody response together with a carrier protein, such as an albumin, to an animal system (such as, for example, rabbit or mouse), or, if the polypeptide is of sufficient length (at least about 25 amino acids), the polypeptide may be presented without a carrier. However, immunogenic epitopes comprising as few as 8 to 10 amino acids have been shown to be sufficient to raise antibodies capable of binding to, at the very least, linear epitopes in a denatured polypeptide (e.g., in Western blotting).

[0151] Epitope-bearing polypeptides of the present invention may be used to induce antibodies according to methods well known in the art including, but not limited to, in vivo immunization, in vitro immunization, and phage display methods. See, e.g., Sutcliffe et al., supra; Wilson et al., supra, and Bittle et al., J. Gen. Virol., 66:2347-2354 (1985). If in vivo immunization is used, animals may be immunized with free peptide; however, anti-peptide antibody titer may be boosted by coupling the peptide to a macromolecular carrier, such as keyhole limpet hemacyanin (KLH) or tetanus toxoid. For instance, peptides containing cysteine residues may be coupled to a carrier using a linker such as maleimidobenzoyl-N-hydroxysuccinimide ester (MBS), while other peptides may be coupled to carriers using a more general linking agent such as glutaraldehyde. Animals such as, for example, rabbits, rats, and mice are immunized with either free or carrier-coupled peptides, for instance, by intraperitoneal and/or intradermal injection of emulsions containing about 100 micrograms of peptide or carrier protein and Freund's adjuvant or any other adjuvant known for stimulating an immune response. Several booster injections may be needed, for instance, at intervals of about two weeks, to provide a useful titer of anti-peptide antibody that can be detected, for example, by ELISA assay using free peptide adsorbed to a solid surface. The titer of anti-peptide antibodies in serum from an immunized animal may be increased by selection of anti-peptide antibodies, for instance, by adsorption to the peptide on a solid support and elution of the selected antibodies according to methods well known in the art.

[0152] As one of skill in the art will appreciate, DR5 receptor polypeptides of the present invention and the epitope-bearing fragments thereof described herein (e.g., corresponding to a portion of the extracellular domain, such as, for example, amino acid residues 1 to 133 of SEQ ID NO:2) can be combined with heterologous polypeptide sequences. For example, the polypeptides of the present invention may be fused with the constant domain of immunoglobulins (IgA, IgE, IgG, IgM) or portions thereof (CH1, CH2, CH3, and any combination thereof, including both entire domains and portions thereof), resulting in chimeric polypeptides. These fusion proteins facilitate purification and show an increased half-life. This has been shown, e.g., for chimeric proteins consisting of the first two domains of the human CD4-polypeptide and various domains of the constant regions of the heavy or light chains of mammalian immunoglobulins (EPA 394,827; Traunecker et al., Nature 331:84-86(1988)). Fusion proteins that have a disulfide-linked dimeric structure due to the IgG part can also be more efficient in binding and neutralizing other molecules than the monomeric DR5 protein or protein fragment alone (Fountoulakis et al., J Biochem. 270:3958-3964(1995)). Nucleic acids encoding the above epitopes can also be recombined with a gene of interest as an epitope tag (e.g., the hemagglutinin (HA) tag or flag tag) to aid in detection and purification of the expressed polypeptide. For example, a system described by Janknecht et al. allows for the ready purification of non-denatured fusion proteins expressed in human cell lines (Janknecht et al., 1991, Proc. Natl. Acad. Sci. USA 88:8972-897). In this system, the gene of interest is subcloned into a vaccinia recombination plasmid such that the open reading frame of the gene is translationally fused to an amino-terminal tag consisting of six histidine residues. The tag serves as a matrix-binding domain for the fusion protein. Extracts from cells infected with the recombinant vaccinia virus are loaded onto Ni² nitriloacetic acid-agarose column and histidine-tagged proteins can be selectively eluted with imidazole-containing buffers. Polynucleotides encoding these fusion proteins are also encompassed by the invention.

[0153] The techniques of gene-shuffling, motif-shuffling, exon-shuffling, and/or codon-shuffling (collectively referred to as DNA shuffling) may be employed to modulate the activities of DR5 thereby effectively generating agonists and antagonists of DR5. See generally, U.S. Pat. Nos. 5,605,793, 5,811,238, 5,830,721, 5,834,252, and 5,837,458, and Patten, P. A., et al., Curr. Opinion Biolechnol. 8:724-33 (1997); Harayama, S. Trends Biotechnol. 16(2):76-82 (1998); Hansson, L. O., et al., J Mol. Biol. 287:265-76 (1999); and Lorenzo, M. M. and Blasco, R. BioTechniques 24(2):308-13 (1998) (each of these patents and publications are hereby incorporated by reference). In one embodiment, alteration of DR5 polynucleotides and corresponding polypeptides may be achieved by DNA shuffling. DNA shuffling involves the assembly of two or more DNA segments into a desired DR5 molecule by homologous, or site-specific, recombination. In another embodiment, DR5 polynucleotides and corresponding polypeptides may be altered by being subjected to random mutagenesis by error-prone PCR, random nucleotide insertion or other methods prior to recombination.

[0154] In another embodiment, one or more components, motifs, sections, parts, domains, fragments, etc., of DR5 may be recombined with one or more components, motifs, sections, parts, domains, fragments, etc. of one or more heterologous molecules. In preferred embodiments, the heterologous molecules are, for example, TNF-alpha, lymphotoxin-alpha (LT-alpha, also known as TNF-beta), LT-beta (found in complex heterotrimer LT-alpha2-beta), OPGL, FasL, CD27L, CD30L, CD40L, 4-1BBL, DcR3, OX40L, TNF-gamma (International Publication No. WO 96/14328), AIM-I (International Publication No. WO 97/33899), AIM-II (International Publication No. WO 97/34911), APRIL (J. Exp. Med. 188(6):1185-1190), endokine-alpha (International Publication No. WO 98/07880), Neutrokine-alpha (International Publication No. WO 98/18921), OPG, nerve growth factor (NGF), DR3 (International Publication No. WO 97/33904), DR4 (International Publication No. WO 98/32856), TR5 (International Publication No. WO 98/30693), TR6 (International Publication No. WO 98/30694), TRANK, TR9 (International Publication No. WO 98/56892), TR10 (International Publication No. WO 98/54202), 312C2 (International Publication No. WO 98/06842), TR12, TNF-R1, TRAMP/DR3/APO-3/WSL/LARD, TRAIL-R1/DR4/APO-2, TRAIL-R2/DR5, DcR1/TRAIL-R3/TRID/LIT, DcR2/TRAIL-R4, CAD, TRAIL, TRAMP, and v-FLIP. In additional preferred embodiments, the heterologous molecules are, for example, soluble forms of Fas, CD30, CD27, CD40 and 4-IBB.

[0155] In further preferred embodiments, the heterologous molecules are any member of the TNF family.

[0156] To improve or alter the characteristics of DR5 polypeptides, protein engineering may be employed. Recombinant DNA technology known to those skilled in the art can be used to create novel mutant proteins or muteins including single or multiple amino acid substitutions, deletions, additions or fusion proteins. Such modified polypeptides can show, e.g., enhanced activity or increased stability. In addition, they may be purified in higher yields and show better solubility than the corresponding natural polypeptide, at least under certain purification and storage conditions.

[0157] For instance, for many proteins, including the extracellular domain of a membrane associated protein or the mature form(s) of a secreted protein, it is known in the art that one or more amino acids may be deleted from the N-terminus or C-terminus without substantial loss of biological function. However, even if deletion of one or more amino acids from the N-terminus or C-terminus of a protein results in modification or loss of one or more biological functions of the protein, other DR5 functional activities may still be retained. For example, in many instances, the ability of the shortened protein to induce and/or bind to antibodies which recognize DR5 (preferably antibodies that bind specifically to DR5) will retained irrespective of the size or location of the deletion. In fact, polypeptides composed of as few as six DR5 amino acid residues may often evoke an immune response. Whether a particular polypeptide lacking N-terminal and/or C-terminal residues of a complete protein retains such immunologic activities can readily be determined by routine methods described herein and otherwise known in the art.

[0158] As mentioned above, even if deletion of one or more amino acids from the N-terminus of a protein results in modification or loss of one or more biological functions of the protein, other functional activities (e.g., biological activities, ability to multimerize, ability to bind DR5 ligand) may still be retained. For example, the ability of shortened DR5 muteins to induce and/or bind to antibodies which recognize the complete or mature forms of the polypeptides generally will be retained when less than the majority of the residues of the complete or mature polypeptide are removed from the N-terminus. Whether a particular polypeptide lacking N-terminal residues of a complete polypeptide retains such immunologic activities can readily be determined by routine methods described herein and otherwise known in the art. It is not unlikely that a DR5 mutein with a large number of deleted N-terminal amino acid residues may retain some biological or immunogenic activities.

[0159] It will be recognized in the art that some amino acid sequence of DR5 can be varied without significant effect on the structure or function of the protein. If such differences in sequence are contemplated, it should be remembered that there will be critical areas on the protein which determine activity. Such areas will usually comprise residues which make up the ligand binding site or the death domain, or which form tertiary structures which affect these domains.

[0160] Accordingly, the present invention further provides polypeptides having one or more residues deleted from the amino terminus of the DR5 amino acid sequence shown in FIG. 1, up to the alanine residue at position number 406 and polynucleotides encoding such polypeptides. In particular, the present invention provides polypeptides comprising, or alternatively consisting of, the amino acid sequence of residues n¹-411 of FIG. 1, where n¹ is an integer from 2 to 406 corresponding to the position of the amino acid residue in FIG. 1 (which is identical to the sequence shown as SEQ ID NO:2, with the exception that the amino acid residues in FIG. 1 are numbered consecutively from 1 through 411 from the N-terminus to the C-terminus, while the amino acid residues in SEQ ID NO:2 are numbered consecutively from 51 through 360 to reflect the position of the predicted signal peptide).

[0161] More in particular, the invention provides polynucleotides encoding polypeptides comprising, or alternatively consisting of, the amino acid sequence of a member selected from the group consisting of residues: E-2 to S-411; Q-3 to S-411; R-4 to S-411; G-5 to S-411; Q-6 to S-411; N-7 to S-411; A-8 to S-411; P-9 to S-411; A-10 to S-411; A-11 to S-411; S-12 to S-411; G-13 to S-411; A-14 to S-411; R-15 to S-411; K-16 to S-411; R-17 to S-411; H-18 to S-411; G-19 to S-411; P-20 to S-411; G-21 to S-411; P-22 to S-411; R-23 to S-411; E-24 to S-411; A-25 to S-411; R-26 to S-411; G-27 to S-411; A-28 to S-411; R-29 to S-411; P-30 to S-411; G-31 to S-411; P-32 to S-411; R-33 to S-411; V-34 to S-411; P-35 to S-411; K-36 to S-411; T-37 to S-411; L-38 to S-411; V-39 to S-411; L-40 to S-411; V-41 to S-411; V-42 to S-411; A-43 to S-411; A-44 to S-411; V-45 to S-411; L-46 to S-411; L-47 to S-411; L-48 to S-411; V-49 to S-411; S-50 to S-411; A-51 to S-411; E-52 to S-411; S-53 to S-411; A-54 to S-411; L-55 to S-411; I-56 to S-411; T-57 to S-411; Q-58 to S-411; Q-59 to S-411; D-60 to S-411; L-61 to S-411; A-62 to S-411; P-63 to S-411; Q-64 to S-411; Q-65 to S-411; R-66 to S-411; A-67 to S-411; A-68 to S-411; P-69 to S-411; Q-70 to S-411; Q-71 to S-411; K-72 to S-411; R-73 to S-411; S-74 to S-411; S-75 to S-411; P-76 to S-411; S-77 to S-411; E-78 to S-411; G-79 to S-411; L-80 to S-411; C-81 to S-411; P-82 to S-411; P-83 to S-411; G-84 to S-411; H-85 to S-411; H-86 to S-411; I-87 to S-411; S-88 to S-411; E-89 to S-411; D-90 to S-411; G-91 to S-411; R-92 to S-411; D-93 to S-411; C-94 to S-411; I-95 to S-411; S-96 to S-411; C-97 to S-411; K-98 to S-411; Y-99 to S-411; G-100 to S-411; Q-101 to S-411; D-102 to S-411; Y-103 to S-411; S-104 to S-411; T-105 to S-411; H-106 to S-411; W-107 to S-411, N-108 to S-411; D-109 to S-411; L-110 to S-411; L-111 to S-411; F-112 to S-411; C-113 to S-411; L-114 to S-411; R-115 to S-411; C-116 to S-411; T-117 to S-411; R-118 to S-411; C-119 to S-411; D-120 to S-411; S-121 to S-411; G-122 to S-411; E-123 to S-411; V-124 to S-411; E-125 to S-411; L-126 to S-411; S-127 to S-411; P-128 to S-411; C-129 to S-411; T-130 to S-411; T-131 to S-411; T-132 to S-411; R-133 to S-411; N-134 to S-411; T-135 to S-411; V-136 to S-411; C-137 to S-411; Q-138 to S-411; C-139 to S-411; E-140 to S-411; E-141 to S-411; G-142 to S-411; T-143 to S-411; F-144 to S-411; R-145 to S-411; E-146 to S-411; E-147 to S-411; D-148 to S-411;S-149 to S-411; P-150 to S-411; E-151 to S-411; M-152 to S-411; C-153 to S-411; R-154 to S-411; K-155 to S-411; C-156 to S-411; R-157 to S-411; T-158 to S-411; G-159 to S-411; C-160 to S-411; P-161 to S-411; R-162 to S-411; G-163 to S-411; M-164 to S-411; V-165 to S-411; K-166 to S-411; V-167 to S-411; G-168 to S-411; D-169 to S-411; C-170 to S-411; T-171 to S-411; P-172 to S-411; W-173 to S-411; S-174 to S-411; D-175 to S-411; I-176 to S-411; E-177 to S-411; C-178 to S-411; V-179 to S-411; H-180 to S-411; K-181 to S-411; E-182 to S-411; S-183 to S-411; G-184 to S-411; I-185 to S-411; I-186 to S-411; I-187 to S-411; G-188 to S-411; V-189 to S-411; T-190 to S-411; V-191 to S-411; A-192 to S-411; A-193 to S-411; V-194 to S-411; V-195 to S-411; L-196 to S-411; I-197 to S-411; V-198 to S-411; A-199 to S-411; V-200 to S-411; F-201 to S-411; V-202 to S-411; C-203 to S-411; K-204 to S-411; S-205 to S-411; L-206 to S-411; L-207 to S-411; W-208 to S-411; K-209 to S-411; K-210 to S-411; V-211 to S-411; L-212 to S-411; P-213 to S-411; Y-214 to S-411; L-215 to S-411; K-216 to S-411; G-217 to S-411; I-218 to S-411; C-219 to S-411; S-220 to S-411; G-221 to S-411; G-222 to S-411; G-223 to S-411; G-224 to S-411; D-225 to S-411; P-226 to S-411; E-227 to S-411; R-228 to S-411; V-229 to S-411; D-230 to S-411; R-231 to S-411; S-232 to S-411; S-233 to S-411; Q-234 to S-411; R-235 to S-411; P-236 to S-411; G-237 to S-411; A-238 to S-411; E-239 to S-411; D-240 to S-411; N-241 to S-411; V-242 to S-411; L-243 to S-411; N-244 to S-411; E-245 to S-411; I-246 to S-411; V-247 to S-411; S-248 to S-411; I-249 to S-411; L-250 to S-411; Q-251 to S-411; P-252 to S-411; T-253 to S-411; Q-254 to S-411; V-255 to S-411; P-256 to S-411; E-257 to S-411; Q-258 to S-411; E-259 to S-411; M-260 to S-411; E-261 to S-411; V-262 to S-411; Q-263 to S-411; E-264 to S-411; P-265 to S-411; A-266 to S-411; E-267 to S-411; P-268 to S-411; T-269 to S-411; G-270 to S-411; V-271 to S-411; N-272 to S-411; M-273 to S-411; L-274 to S-411; S-275 to S-411; P-276 to S-411; G-277 to S-411; E-278 to S-411; S-279 to S-411; E-280 to S-411; H-281 to S-411; L-282 to S-411; L-283 to S-411; E-284 to S-411; P-285 to S-411; A-286 to S-411; E-287 to S-411; A-288 to S-411; E-289 to S-411; R-290 to S-411; S-291 to S-411; Q-292 to S-411; R-293 to S-411; R-294 to S-411; R-295 to S-411; L-296 to S-411; L-297 to S-411; V-298 to S-411; P-299 to S-411; A-300 to S-411; N-301 to S-411; E-302 to S-411; G-303 to S-411; D-304 to S-411; P-305 to S-411; T-306 to S-411; E-307 to S-411; T-308 to S-411; L-309 to S-411; R-310 to S-411; Q-311 to S-411; C-312 to S-411;F-313 to S-411; D-314 to S-411; D-315 to S-411; F-316 to S-411; A-317 to S-411; D-318 to S-411; L-319 to S-411; V-320 to S-411; P-321 to S-411; F-322 to S-411; D-323 to S-411; S-324 to S-411; W-325 to S-411; E-326 to S-411; P-327 to S-411; L-328 to S-411; M-329 to S-411; R-330 to S-411; K-331 to S-411; L-332 to S-411; G-333 to S-411; L-334 to S-411; M-335 to S-411; D-336 to S-411; N-337 to S-411; E-338 to S-411; I-339 to S-411; K-340 to S-411; V-341 to S-411; A-342 to S-411; K-343 to S-411; A-344 to S-411; E-345 to S-411; A-346 to S-411; A-347 to S-411; G-348 to S-411; H-349 to S-411; R-350 to S-411; D-351 to S-411; T-352 to S-411; L-353 to S-411;Y-354 to S-411; T-355 to S-411; M-356 to S-411; L-357 to S-411; I-358 to S-411; K-359 to S-411; W-360 to S-411; V-361 to S-411; N-362 to S-411; K-363 to S-411; T-364 to S-411; G-365 to S-411; R-366 to S-411; D-367 to S-411; A-368 to S-411; S-369 to S-411; V-370 to S-411; H-371 to S-411; T-372 to S-411; L-373 to S-411 L-374 to S-411; D-375 to S-411; A-376 to S-411; L-377 to S-411; E-378 to S-411; T-379 to S-411; L-380 to S-411; G-381 to S-411; E-382 to S-411; R-383 to S-411; L-384 to S-411; A-385 to S-411; K-386 to S-411; Q-387 to S-411; K-388 to S-411; I-389 to S-411; E-390 to S-411; D-391 to S-411; H-392 to S-411; L-393 to S-411; L-394 to S-411; S-395 to S-411; S-396 to S-411; G-397 to S-411; K-398 to S-411; F-399 to S-411; M-400 to S-411; Y-401 to S-411; L-402 to S-411; E-403 to S-411; G-404 to S-411; N-405 to S-411; and A-406 to S-411 of the DR5 sequence shown in FIG. 1 (which is identical to the sequence shown as SEQ ID NO:2, with the exception that the amino acid residues in FIG. 1 are numbered consecutively from 1 through 411 from the N-terminus to the C-terminus, while the amino acid residues in SEQ ID NO:2 are numbered consecutively from 51 through 360 to reflect the position of the predicted signal peptide).

[0162] The present invention is also directed to nucleic acid molecules comprising, or alternatively consisting of, a polynucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polynucleotide sequences encoding the polypeptides described above. The invention is further directed to nucleic acid molecules comprising, or alternatively consisting of, polynucleotide sequences which encode polypeptides that are at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polypeptides described above. The present invention also encompasses the above polynucleotide sequences fused to a heterologous polynucleotide sequence. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0163] In another embodiment, N-terminal deletions of the DR5 polypeptide can be described by the general formula n² to 184 where n² is a number from 1 to 179 corresponding to the amino acid sequence identified in FIG. 1 (or where n² is a number from 51 to 128 corresponding to the amino acid sequence identified in SEQ ID NO:2). In specific embodiments, N-terminal deletions of the DR5 of the invention comprise, or alternatively consist of, a member selected from the group consisting of amino acid residues: E-2 to G-184; Q-3 to G-184; R-4 to G-184; G-5 to G-184; Q-6 to G-184; N-7 to G-184; A-8 to G-184; P-9 to G-184; A-10 to G-184; A-11 to G-184; S-12 to G-184; G-13 to G-184; A-14 to G-184; R-15 to G-184; K-16 to G-184; R-17 to G-184; H-18 to G-184; G-19 to G-184; P-20 to G-184; G-21 to G-184; P-22 to G-184; R-23 to G-184; E-24 to G-184; A-25 to G-184; R-26 to G-184; G-27 to G-184; A-28 to G-184; R-29 to G-184; P-30 to G-184; G-31 to G-184; P-32 to G-184; R-33 to G-184; V-34 to G-184; P-35 to G-184; K-36 to G-184; T-37 to G-184; L-38 to G-184; V-39 to G-184; L-40 to G-184; V-41 to G-184; V-42 to G-184; A-43 to G-184; A-44 to G-184; V-45 to G-184; L-46 to G-184; L-47 to G-184; L-48 to G-184; V-49 to G-184; S-50 to G-184; A-51 to G-184; E-52 to G-184; S-53 to G-184; A-54 to G-184; L-55 to G-184; I-56 to G-184; T-57 to G-184; Q-58 to G-184; Q-59 to G-184; D-60 to G-184; L-61 to G-184; A-62 to G-184; P-63 to G-184; Q-64 to G-184; Q-65 to G-184; R-66 to G-184; A-67 to G-184; A-68 to G-184; P-69 to G-184; Q-70 to G-184; Q-71 to G-184; K-72 to G-184; R-73 to G-184; S-74 to G-184; S-75 to G-184; P-76 to G-184; S-77 to G-184; E-78 to G-184; G-79 to G-184; L-80 to G-184; C-81 to G-184; P-82 to G-184; P-83 to G-184; G-84 to G-184; H-85 to G-184; H-86 to G-184; I-87 to G-184; S-88 to G-184; E-89 to G-184; D-90 to G-184; G-91 to G-184; R-92 to G-184; D-93 to G-184; C-94 to G-184; I-95 to G-184; S-96 to G-184; C-97 to G-184; K-98 to G-184; Y-99 to G-184; G-100 to G-184; Q-101 to G-184; D-102 to G-184; Y-103 to G-184; S-104 to G-184; T-105 to G-184; H-106 to G-184; W-107 to G-184; N-108 to G-184; D-109 to G-184; L-110 to G-184; L-111 to G-184; F-12 to G-184; C-113 to G-184; L-114 to G-184; R-115 to G-184; C-116 to G-184; T-117 to G-184; R-118 to G-184; C-119 to G-184; D-120 to G-184; S-121 to G-184; G-122 to G-184; E-123 to G-184; V-124 to G-184; E-125 to G-184; L-126 to G-184; S-127 to G-184; P-128 to G-184; C-129 to G-184; T-130 to G-184; T-131 to G-184; T-132 to G-184; R-133 to G-184; N-134 to G-184; T-135 to G-184; V-136 to G-184; C-137 to G-184; Q-138 to G-184; C-139 to G-184; E-140 to G-184; E-141 to G-184; G-142 to G-184; T-143 to G-184; F-144 to G-184; R-145 to G-184; E-146 to G-184; E-147 to G-184; D-148 to G-184; S-149 to G-184; P-150 to G-184; E-151 to G-184; M-152 to G-184; C-153 to G-184; R-154 to G-184; K-155 to G-184; C-156 to G-184; R-157 to G-184; T-158 to G-184; G-159 to G-184; C-160 to G-184; P-161 to G-184; R-162 to G-184; G-163 to G-184; M-164 to G-184; V-165 to G-184; K-166 to G-184; V-167 to G-184; G-168 to G-184; D-169 to G-184; C-170 to G-184; T-171 to G-184; P-172 to G-184; W-173 to G-184; S-174 to G-184; D-175 to G-184; I-176 to G-184; E-177 to G-184; C-178 to G-184; and V-179 to G-184 of the DR5 extracellular domain sequence shown in FIG. 1 (which is identical to the sequence shown as SEQ ID NO:2, with the exception that the amino acid residues in FIG. 1 are numbered consecutively from 1 through 411 from the N-terminus to the C-terminus, while the amino acid residues in SEQ ID NO:2 are numbered consecutively from 51 through 360 to reflect the position of the predicted signal peptide).

[0164] The present invention is also directed to nucleic acid molecules comprising, or alternatively consisting of, a polynucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polynucleotide sequences encoding the polypeptides described above. The invention is further directed to nucleic acid molecules comprising, or alternatively consisting of, polynucleotide sequences which encode polypeptides that are at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polypeptides described above. The present invention also encompasses the above polynucleotide sequences fused to a heterologous polynucleotide sequence. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0165] Also as mentioned above, even if deletion of one or more amino acids from the C-terminus of a protein results in modification of loss of one or more biological functions of the protein, other functional activities (e.g., biological activities, ability to multimerize, ability to bind DR5 ligand (e.g., TRAIL)) may still be retained. For example, the ability of the shortened DR5 mutein to induce and/or bind to antibodies which recognize the complete or mature forms of the polypeptide generally will be retained when less than the majority of the residues of the complete or mature polypeptide are removed from the C-terminus. Whether a particular polypeptide lacking C-terminal residues of a complete polypeptide retains such immunologic activities can readily be determined by routine methods described herein and otherwise known in the art. It is not unlikely that a DR5 mutein with a large number of deleted C-terminal amino acid residues may retain some biological or immunogenic activities. In fact, peptides composed of as few as six DR5 amino acid residues may often evoke an immune response.

[0166] Accordingly, the present invention further provides polypeptides having one or more residues deleted from the carboxy terminus of the amino acid sequence of the DR5 polypeptide shown in FIG. 1 (SEQ ID NO:2), up to the glutamic acid residue at position number 52, and polynucleotides encoding such polypeptides. In particular, the present invention provides polypeptides comprising, or alternatively consisting of, the amino acid sequence of residues 52-m¹ of FIG. 1 (i.e., SEQ ID NO:2), where m¹ is an integer from 57 to 410 corresponding to the position of the amino acid residue in FIG. 1 (or where m¹ is an integer from 6 to 360 corresponding to the position of the amino acid residue in SEQ ID NO:2). More in particular, the invention provides polynucleotides encoding polypeptides comprising, or alternatively consisting of, a member selected from the group consisting of residues: E-52 to M-410; E-52 to A-409; E-52 to S-408; E-52 to D-407; E-52 to A-406; E-52 to N-405; E-52 to G-404; E-52 to E-403; E-52 to L-402; E-52 to Y-401; E-52 to M-400; E-52 to F-399; E-52 to K-398; E-52 to G-397; E-52 to S-396; E-52 to S-395; E-52 to L-394; E-52 to L-393; E-52 to H-392; E-52 to D-391; E-52 to E-390; E-52 to I-389; E-52 to K-388; E-52 to Q-387; E-52 to K-386; E-52 to A-385; E-52 to L-384; E-52 to R-383; E-52 to E-382; E-52 to G-381; E-52 to L-380; E-52 to T-379; E-52 to E-378; E-52 to L-377; E-52 to A-376; E-52 to D-375; E-52 to L-374; E-52 to L-373; E-52 to T-372; E-52 to H-371; E-52 to V-370; E-52 to S-369; E-52 to A-368; E-52 to D-367; E-52 to R-366; E-52 to G-365; E-52 to T-364; E-52 to K-363; E-52 to N-362; E-52 to V-361; E-52 to W-360; E-52 to K-359; E-52 to I-358; E-52 to L-357; E-52 to M-356; E-52 to T-355; E-52 to Y-354; E-52 to L-353; E-52 to T-352; E-52 to D-351; E-52 to R-350; E-52 to H-349; E-52 to G-348; E-52 to A-347; E-52 to A-346; E-52 to E-345; E-52 to A-344; E-52 to K-343; E-52 to A-342; E-52 to V-341; E-52 to K-340; E-52 to I-339; E-52 to E-338; E-52 to N-337; E-52 to D-336; E-52 to M-335; E-52 to L-334; E-52 to G-333; E-52 to L-332; E-52 to K-331; E-52 to R-330; E-52 to M-329; E-52 to L-328; E-52 to P-327; E-52 to E-326; E-52 to W-325; E-52 to S-324; E-52 to D-323; E-52 to F-322; E-52 to P-321; E-52 to V-320; E-52 to L-319; E-52 to D-318; E-52 to A-317; E-52 to F-316; E-52 to D-315; E-52 to D-314; E-52 to F-313; E-52 to C-312; E-52 to Q-311; E-52 to R-310; E-52 to L-309; E-52 to T-308; E-52 to E-307; E-52 to T-306; E-52 to P-305; E-52 to D-304; E-52 to G-303; E-52 to E-302; E-52 to N-301; E-52 to A-300; E-52 to P-299; E-52 to V-298; E-52 to L-297; E-52 to L-296; E-52 to R-295; E-52 to R-294; E-52 to R-293; E-52 to Q-292; E-52 to S-291; E-52 to R-290; E-52 to E-289; E-52 to A-288; E-52 to E-287; E-52 to A-286; E-52 to P-285; E-52 to E-284; E-52 to L-283; E-52 to L-282; E-52 to H-281; E-52 to E-280; E-52 to S-279; E-52 to E-278; E-52 to G-277; E-52 to P-276; E-52 to S-275; E-52 to L-274; E-52 to M-273; E-52 to N-272; E-52 to V-271; E-52 to G-270; E-52 to T-269; E-52 to P-268; E-52 to E-267; E-52 to A-266; E-52 to P-265; E-52 to E-264; E-52 to Q-263; E-52 to V-262; E-52 to E-261; E-52 to M-260; E-52 to E-259; E-52 to Q-258; E-52 to E-257; E-52 to P-256; E-52 to V-255; E-52 to Q-254; E-52 to T-253; E-52 to P-252; E-52 to Q-251; E-52 to L-250; E-52 to I-249; E-52 to S-248; E-52 to V-247; E-52 to I-246; E-52 to E-245; E-52 to N-244; E-52 to L-243; E-52 to V-242; E-52 to N-241; E-52 to D-240; E-52 to E-239; E-52 to A-238; E-52 to G-237; E-52 to P-236; E-52 to R-235; E-52 to Q-234; E-52 to S-233; E-52 to S-232; E-52 to R-231; E-52 to D-230; E-52 to V-229; E-52 to R-228; E-52 to E-227; E-52 to P-226; E-52 to D-225; E-52 to G-224; E-52 to G-223; E-52 to G-222; E-52 to G-221; E-52 to S-220; E-52 to C-219; E-52 to I-218; E-52 to G-217; E-52 to K-216; E-52 to L-215; E-52 to Y-214; E-52 to P-213; E-52 to L-212; E-52 to V-211; E-52 to K-210; E-52 to K-209, E-52 to W-208; E-52 to L-207; E-52 to L-206; E-52 to S-205; E-52 to K-204; E-52 to C-203; E-52 to V-202; E-52 to F-201; E-52 to V-200; E-52 to A-199; E-52 to V-198; E-52 to I-197; E-52 to L-196; E-52 to V-195; E-52 to V-194; E-52 to A-193; E-52 to A-192; E-52 to V-191; E-52 to T-190; E-52 to V-189; E-52 to G-188; E-52 to I-187; E-52 to I-186; E-52 to I-185; E-52 to G-184; E-52 to S-183; E-52 to E-182; E-52 to K-181; E-52 to H-180; E-52 to V-179; E-52 to C-178; E-52 to E-177; E-52 to I-176; E-52 to D-175; E-52 to S-174; E-52 to W-173; E-52 to P-172; E-52 to T-171; E-52 to C-170; E-52 to D-169; E-52 to G-168; E-52 to V-167; E-52 to K-166; E-52 to V-165; E-52 to M-164; E-52 to G-163; E-52 to R-162; E-52 to P-161; E-52 to C-160; E-52 to G-159; E-52 to T-158; E-52 to R-157; E-52 to C-156; E-52 to K-155; E-52 to R-154; E-52 to C-153; E-52 to M-152; E-52 to E-151; E-52 to P-150; E-52 to S-149; E-52 to D-148; E-52 to E-147; E-52 to E-146; E-52 to R-145; E-52 to F-144; E-52 to T-143; E-52 to G-142; E-52 to E-141; E-52 to E-140; E-52 to C-139; E-52 to Q-138; E-52 to C-137; E-52 to V-136; E-52 to T-135; E-52 to N-134; E-52 to R-133; E-52 to T-132; E-52 to T-131; E-52 to T-130; E-52 to C-129; E-52 to P-128, E-52 to S-127; E-52 to L-126; E-52 to E-125; E-52 to V-124; E-52 to E-123; E-52 to G-122; E-52 to S-121; E-52 to D-120; E-52 to C-119; E-52 to R-118; E-52 to T-117; E-52 to C-116; E-52 to R-115; E-52 to L-114; E-52 to C-113; E-52 to F-112; E-52 to L-111; E-52 to L-110; E-52 to D-109; E-52 to N-108; E-52 to W-107; E-52 to H-106; E-52 to T-105; E-52 to S-104; E-52 to Y-103; E-52 to D-102; E-52 to Q-101; E-52 to G-100; E-52 to Y-99; E-52 to K-98; E-52 to C-97; E-52 to S-96; E-52 to I-95; E-52 to C-94; E-52 to D-93; E-52 to R-92; E-52 to G-91; E-52 to D-90; E-52 to E-89; E-52 to S-88; E-52 to I-87; E-52 to H-86; E-52 to H-85; E-52 to G-84; E-52 to P-83; E-52 to P-82; E-52 to C-81; E-52 to L-80; E-52 to G-79; E-52 to E-78; E-52 to S-77; E-52 to P-76; E-52 to S-75; E-52 to S-74; E-52 to R-73; E-52 to K-72; E-52 to Q-71; E-52 to Q-70; E-52 to P-69; E-52 to A-68; E-52 to A-67; E-52 to R-66; E-52 to Q-65; E-52 to Q-64; E-52 to P-63; E-52 to A-62; E-52 to L-61; E-52 to D-60; E-52 to Q-59; E-52 to Q-58; and E-52 to T-57; of the DR5 sequence shown in FIG. 1 (which is identical to the sequence shown as SEQ ID NO:2, with the exception that the amino acid residues in FIG. 1 are numbered consecutively from 1 through 411 from the N-terminus to the C-terminus, while the amino acid residues in SEQ ID NO:2 are numbered consecutively from 51 through 360 to reflect the position of the predicted signal peptide).

[0167] The present invention is also directed to nucleic acid molecules comprising, or alternatively consisting of, a polynucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polynucleotide sequences encoding the polypeptides described above. The invention is further directed to nucleic acid molecules comprising, or alternatively consisting of, polynucleotide sequences which encode polypeptides that are at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polypeptides described above. The present invention also encompasses the above polynucleotide sequences fused to a heterologous polynucleotide sequence. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0168] In another embodiment, C-terminal deletions of the DR5 polypeptide can be described by the general formula 52-m² where m² is a number from 57 to 183 corresponding to the amino acid sequence identified in FIG. 1 (SEQ ID NO:2). In specific embodiments, C-terminal deletions of the DR5 of the invention comprise, or alternatively, consist of, a member selected from the group consisting of residues: E-52 to S-183; E-52 to E-182; E-52 to K-181, E-52 to H-180; E-52 to V-179; E-52 to C-178; E-52 to E-177; E-52 to I-176; E-52 to D-175; E-52 to S-174; E-52 to W-173; E-52 to P-172; E-52 to T-171; E-52 to C-170; E-52 to D-169; E-52 to G-168; E-52 to V-167; E-52 to K-166; E-52 to V-165; E-52 to M-164; E-52 to G-163; E-52 to R-162; E-52 to P-161; E-52 to C-160; E-52 to G-159; E-52 to T-158; E-52 to R-157; E-52 to C-156; E-52 to K-155; E-52 to R-154; E-52 to C-153; E-52 to M-152; E-52 to E-151; E-52 to P-150; E-52 to S-149; E-52 to D-148; E-52 to E-147; E-52 to E-146; E-52 to R-145; E-52 to F-144; E-52 to T-143; E-52 to G-142; E-52 to E-141; E-52 to E-140; E-52 to C-139; E-52 to Q-138; E-52 to C-137; E-52 to V-136; E-52 to T-135; E-52 to N-134; E-52 to R-133; E-52 to T-132; E-52 to T-131; E-52 to T-130; E-52 to C-129; E-52 to P-128; E-52 to S-127; E-52 to L-126; E-52 to E-125; E-52 to V-124; E-52 to E-123; E-52 to G-122; E-52 to S-121; E-52 to D-120; E-52 to C-119; E-52 to R-118; E-52 to T-117; E-52 to C-116; E-52 to R-115; E-52 to L-114; E-52 to C-113; E-52 to F-112; E-52 to L-111; E-52 to L-110; E-52 to D-109; E-52 to N-108; E-52 to W-107; E-52 to H-106; E-52 to T-105; E-52 to S-104; E-52 to Y-103; E-52 to D-102; E-52 to Q-101; E-52 to G-100; E-52 to Y-99; E-52 to K-98; E-52 to C-97; E-52 to S-96; E-52 to I-95; E-52 to C-94; E-52 to D-93; E-52 to R-92; E-52 to G-91; E-52 to D-90; E-52 to E-89; E-52 to S-88; E-52 to I-87; E-52 to H-86; E-52 to H-85; E-52 to G-84, E-52 to P-83; E-52 to P-82; E-52 to C-81; E-52 to L-80; E-52 to G-79; E-52 to E-78; E-52 to S-77; E-52 to P-76; E-52 to S-75; E-52 to S-74; E-52 to R-73; E-52 to K-72; E-52 to Q-71; E-52 to Q-70; E-52 to P-69; E-52 to A-68; E-52 to A-67; E-52 to R-66; E-52 to Q-65; E-52 to Q-64; E-52 to P-63; E-52 to A-62; E-52 to L-61; E-52 to D-60; E-52 to Q-59; E-52 to Q-58; and E-52 to T-57 of the DR5 extracellular domain sequence shown in FIG. 1 (SEQ ID NO:2).

[0169] The present invention is also directed to nucleic acid molecules comprising, or alternatively consisting of, a polynucleotide sequence at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polynucleotide sequences encoding the polypeptides described above. The invention is further directed to nucleic acid molecules comprising, or alternatively consisting of, polynucleotide sequences which encode polypeptides that are at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98%, or 99% identical to the polypeptides described above. The present invention also encompasses the above polynucleotide sequences fused to a heterologous polynucleotide sequence. Polypeptides encoded by these polynucleotides are also encompassed by the invention.

[0170] The invention also provides polypeptides having one or more amino acids deleted from both the amino and the carboxyl termini of a DR5 polypeptide, which may be described generally as having residues n¹-m¹ and/or n²-m² of FIG. 1 (i.e., SEQ ID NO:2), where n¹, n², m¹, and m² are integers as described above.

[0171] Also included are a nucleotide sequence encoding a polypeptide consisting of a portion of the complete DR5 amino acid sequence encoded by the cDNA contained in ATCC Deposit No. 97920, where this portion excludes from 1 to about 78 amino acids from the amino terminus of the complete amino acid sequence encoded by the cDNA contained in ATCC Deposit No. 97920, or from 1 to about 233 amino acids from the carboxy terminus, or any combination of the above amino terminal and carboxy terminal deletions, of the complete amino acid sequence encoded by the cDNA contained in ATCC Deposit No. 97920. Polynucleotides encoding all of the above deletion mutant polypeptide forms also are provided.

[0172] Preferred amongst the N- and C-terminal deletion mutants are those comprising, or alternatively consisting of, only a portion of the extracellular domain; i.e., within residues 52-184, since any portion therein is expected to be soluble.

[0173] It will be recognized in the art that some amino acid sequence of DR5 can be varied without significant effect of the structure or function of the protein. If such differences in sequence are contemplated, it should be remembered that 30 there will be critical areas on the protein which determine activity. Such areas will usually comprise residues which make up the ligand binding site or the death domain, or which form tertiary structures which affect these domains.

[0174] Thus, the invention further includes variations of the DR5 protein which show substantial DR5 protein activity or which include regions of DR5, such as the protein portions discussed below. Such mutants include deletions, insertions, inversions, repeats, and type substitutions. As indicated above, guidance concerning which amino acid changes are likely to be phenotypically silent can be found in Bowie, J. U. et al., Science 247:1306-1310 (1990).

[0175] Thus, the fragment, derivative, or analog of the polypeptide of SEQ ID NO:2, or that encoded by the deposited cDNA, may be (i) one in which at least one or more of the amino acid residues are substituted with a conserved or non-conserved amino acid residue (preferably a conserved amino acid residue(s), and more preferably at least one but less than ten conserved amino acid residues) and such substituted amino acid residue may or may not be one encoded by the genetic code, or (ii) one in which one or more of the amino acid residues includes a substituent group, or (iii) one in which the mature polypeptide is fused with another compound, such as a compound to increase the half-life of the polypeptide (for example, polyethylene glycol), or (iv) one in which the additional amino acids are fused to the mature polypeptide, such as an IgG Fc fusion region peptide or leader or secretory sequence or a sequence which is employed for purification of the mature polypeptide or a proprotein sequence. Such fragments, derivatives and analogs are deemed to be within the scope of those skilled in the art from the teachings herein. Polynucleotides encoding these fragments, derivatives or analogs are also encompassed by the invention.

[0176] Of particular interest are substitutions of charged amino acids with another charged amino acids and with neutral or negatively charged amino acids. The latter results in proteins with reduced positive charge to improve the characteristics of the DR5 protein. Additionally, one or more of the amino acid residues of the polypeptides of the invention (e.g., arginine and lysine residues) may be deleted or substituted with another residue to eliminate undesired processing by proteases such as, for example, furins or kexins. The prevention of aggregation is highly desirable. Aggregation of proteins not only results in a loss of activity but can also be problematic when preparing pharmaceutical formulations, because they can be immunogenic. (Pinckard et al., Clin Exp. Immunol. 2:331-340 (1967); Robbins et al., Diabetes 36:838-845 (1987); Cleland et al. Crit. Rev. Therapeutic Drug Carrier Systems 10:307-377 (1993)).

[0177] The replacement of amino acids can also change the selectivity of binding to cell surface receptors. Ostade et al., Nature 361:266-268 (1993) describes certain mutations resulting in selective binding of TNF-alpha to only one of the two known types of TNF receptors. Thus, the DR5 receptor of the present invention may include one or more amino acid substitutions, deletions or additions, either from natural mutations or human manipulation.

[0178] As indicated, changes are preferably of a minor nature, such as conservative amino acid substitutions that do not significantly affect the folding or activity of the protein (see Table II).

TABLE II
Conservative Amino Acid Substitution
	Aromatic	Phenylalanine
		Tryptophan
		Tyrosine
	Hydrophobic	Leucine
		Isoleucine
		Valine
	Polar	Glutamine
		Asparagine
	Basic	Arginine
		Lysine
		Histidine
	Acidic	Aspartic Acid
		Glutamic Acid
	Small	Alanine
		Serine
		Threonine
		Methionine
		Glycine

[0179] In specific embodiments, the number of substitutions, additions or deletions in the amino acid sequence of FIG. 1 and/or any of the polypeptide fragments described herein (e.g., the extracellular domain or intracellular domain) is 75, 70, 60, 50, 40, 35, 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or 30-20, 20-15, 20-10, 15-10, 10-1, 5-10, 1-5, 1-3 or 1-2. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0180] Amino acids in the DR5 protein of the present invention that are essential for function can be identified by methods known in the art, such as site-directed mutagenesis or alanine-scanning mutagenesis (Cunningham and Wells, Science 244:1081-1085 (1989)). The latter procedure introduces single alanine mutations at every residue in the molecule. The resulting mutant molecules are then tested for biological activity such as receptor binding or in vitro, or in vitro proliferative activity. Sites that are critical for ligand-receptor binding can also be determined by structural analysis such as crystallization, nuclear magnetic resonance or photoaffinity labeling (Smith et al., J. Mol. Biol. 224:899-904 (1992) and de Eros et al. Science 255:306-312 (1992)).

[0181] Additionally, protein engineering may be employed to improve or alter the characteristics of DR5 polypeptides. Recombinant DNA technology known to those skilled in the art can be used to create novel mutant proteins or muteins including single or multiple amino acid substitutions, deletions, additions or fusion proteins. Such modified polypeptides can show, e.g., enhanced activity or increased stability. In addition, they may be purified in higher yields and show better solubility than the corresponding natural polypeptide, at least under certain purification and storage conditions.

[0182] Non-naturally occurring variants may be produced using art-known mutagenesis techniques, which include, but are not limited to oligonucleotide mediated mutagenesis, alanine scanning, PCR mutagenesis, site directed mutagenesis (see e.g., Carter et al., Nucl. Acids Res. 13:4331 (1986); and Zoller et al., Nucl. Acids Res. 10:6487 (1982)), cassette mutagenesis (see e.g., Wells et al., Gene 34:315 (1985)), and restriction selection mutagenesis (see e.g., Wells et al., Philos. Trans. R. Soc. London SerA 317:415 (1986)).

[0183] Thus, the invention also encompasses DR5 derivatives and analogs that have one or more amino acid residues deleted, added, or substituted to generate DR5 polypeptides that are better suited for expression, scale up, etc., in the host cells chosen. For example, cysteine residues can be deleted or substituted with another amino acid residue in order to eliminate disulfide bridges; N-linked glycosylation sites can be altered or eliminated to achieve, for example, expression of a homogeneous product that is more easily recovered and purified from yeast hosts which are known to hyperglycosylate N-linked sites. To this end, a variety of amino acid substitutions at one or both of the first or third amino acid positions on any one or more of the glycosylation recognitions sequences in the DR5 polypeptides of the invention, and/or an amino acid deletion at the second position of any one or more such recognition sequences will prevent glycosylation of the DR5 at the modified tripeptide sequence (see, e.g., Miyajimo et al., EMBO J 5(6):1193-1197).

[0184] The polypeptides of the present invention also include a polypeptide comprising, or alternatively consisting of, one, two, three, four, five or more amino acid sequences selected from the group consisting of: the polypeptide encoded by the deposited cDNA (the deposit having ATCC Accession Number 97920) including the leader; the mature polypeptide encoded by the deposited the cDNA minus the leader (i.e., the mature protein); a polypeptide comprising, or alternatively consisting of, amino acids from about 51 to about 360 in SEQ ID NO:2; a polypeptide comprising, or alternatively consisting of, amino acids from about 50 to about 360 in SEQ ID NO:2; a polypeptide comprising, or alternatively consisting of, amino acids from about 1 to about 360 in SEQ ID NO:2; a polypeptide comprising, or alternatively consisting of, the DR5 extracellular domain; a polypeptide comprising, or alternatively consisting of, the DR5 cysteine rich domain; a polypeptide comprising, or alternatively consisting of, the DR5 transmembrane domain; a polypeptide comprising, or alternatively consisting of, the DR5 intracellular domain; a polypeptide comprising, or alternatively consisting of, the extracellular and intracellular domains with all or part of the transmembrane domain deleted; and a polypeptide comprising, or alternatively consisting of, the DR5 death domain; as well as polypeptides which are at least 80% identical, more preferably at least 90% or 95% identical, still more preferably at least 96%, 97%, 98%, or 99% identical to the polypeptides described above, and also include portions of such polypeptides with at least 30 amino acids and more preferably at least 50 amino acids. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0185] By a polypeptide having an amino acid sequence at least, for example, 95% identical to a reference amino acid sequence of a DR5 polypeptide is intended that the amino acid sequence of the polypeptide is identical to the reference sequence except that the polypeptide sequence may include up to five amino acid alterations per each 100 amino acids of the reference amino acid of the DR5 polypeptide. In other words, to obtain a polypeptide having an amino acid sequence at least 95% identical to a reference amino acid sequence, up to 5% of the amino acid residues in the reference sequence may be deleted or substituted with another amino acid, or a number of amino acids up to 5% of the total amino acid residues in the reference sequence may be inserted into the reference sequence. These alterations of the reference sequence may occur at the amino or carboxy terminal positions of the reference amino acid sequence or anywhere between those terminal positions, interspersed either individually among residues in the reference sequence or in one or more contiguous groups within the reference sequence.

[0186] As a practical matter, whether any particular polypeptide is at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to, for instance, the amino acid sequence shown in FIG. 1 (SEQ ID NO:2), the amino acid sequence encoded by the deposited cDNA, or fragments thereof, can be determined conventionally using known computer programs such the Bestfit program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, 575 Science Drive, Madison, Wis. 53711). When using Bestfit or any other sequence alignment program to determine whether a particular sequence is, for instance, 95% identical to a reference sequence according to the present invention, the parameters are set, of course, such that the percentage of identity is calculated over the full length of the reference amino acid sequence and that gaps in homology of up to 5% of the total number of amino acid residues in the reference sequence are allowed.

[0187] In a specific embodiment, the identity between a reference (query) sequence (a sequence of the present invention) and a subject sequence, also referred to as a global sequence alignment, is determined using the FASTDB computer program based on the algorithm of Brutlag et al. (Comp. App. Biosci. 6:237-245 (1990)). Preferred parameters used in a FASTDB amino acid alignment are: MatrixPAM 0, k-tuple2, Mismatch Penalty1, Joining Penalty20, Randomization Group Length0, Cutoff Score1, Window Sizesequence length, Gap Penalty5, Gap Size Penalty0.05, Window Size500 or the length of the subject amino acid sequence, whichever is shorter. According to this embodiment, if the subject sequence is shorter than the query sequence due to N- or C-terminal deletions, not because of internal deletions, a manual correction is made to the results to take into consideration the fact that the FASTDB program does not account for N- and C-terminal truncations of the subject sequence when calculating global percent identity. For subject sequences truncated at the N- and C-termini, relative to the query sequence, the percent identity is corrected by calculating the number of residues of the query sequence that are N- and C-terminal of the subject sequence, which are not matched/aligned with a corresponding subject residue, as a percent of the total bases of the query sequence. A determination of whether a residue is matched/aligned is determined by results of the FASTDB sequence alignment. This percentage is then subtracted from the percent identity, calculated by the above FASTDB program using the specified parameters, to arrive at a final percent identity score. This final percent identity score is what is used for the purposes of this embodiment. Only residues to the N- and C-termini of the subject sequence, which are not matched/aligned with the query sequence, are considered for the purposes of manually adjusting the percent identity score. That is, only query residue positions outside the farthest N- and C-terminal residues of the subject sequence. For example, a 90 amino acid residue subject sequence is aligned with a 100 residue query sequence to determine percent identity. The deletion occurs at the N-terminus of the subject sequence and therefore, the FASTDB alignment does not show a matching/alignment of the first 10 residues at the N-terminus. The 10 unpaired residues represent 10% of the sequence (number of residues at the N- and C-termini not matched/total number of residues in the query sequence) so 10% is subtracted from the percent identity score calculated by the FASTDB program. If the remaining 90 residues were perfectly matched the final percent identity would be 90%. In another example, a 90 residue subject sequence is compared with a 100 residue query sequence. This time the deletions are internal deletions so there are no residues at the N- or C-termini of the subject sequence which are not matched/aligned with the query. In this case the percent identity calculated by FASTDB is not manually corrected. Once again, only residue positions outside the N- and C-terminal ends of the subject sequence, as displayed in the FASTDB alignment, which are not matched/aligned with the query sequence are manually corrected for. No other manual corrections are made for the purposes of this embodiment.

[0188] The polypeptide of the present invention have uses that include, but are not limited to, use as a molecular weight marker on SDS-PAGE gels or on molecular sieve gel filtration columns and as a source for generating antibodies that bind the polypeptides of the invention, using methods well known to those of skill in the art.

[0189] The present application is also directed to proteins containing polypeptides at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to the DR5 polypeptide sequence set forth herein as n¹-m¹, and/or n²-m². In preferred embodiments, the application is directed to proteins containing polypeptides at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to polypeptides having the amino acid sequence of the specific DR5 N- and C-terminal deletions recited herein. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0190] In certain preferred embodiments, DR5 proteins of the invention comprise fusion proteins as described above wherein the DR5 polypeptides are those described as n¹-m¹, and n²-m², herein. In preferred embodiments, the application is directed to nucleic acid molecules at least 80%, 85%, 90%, 92%, 95%, 96%, 97%, 98% or 99% identical to the nucleic acid sequences encoding 10 polypeptides having the amino acid sequence of the specific N- and C-terminal deletions recited herein. Polynucleotides encoding these polypeptides are also encompassed by the invention.

[0191] The present inventors have discovered that the DR5 polypeptide is a 411 residue protein exhibiting three main structural domains. First, the ligand binding domain (extracellular domain) was identified within residues from about 52 to about 184 in FIG. 1 (amino acid residues from about 1 to about 133 in SEQ ID NO:2). Second, the transmembrane domain was identified within residues from about 185 to about 208 in FIG. 1 (amino acid residues from about 134 to about 157 in SEQ ID NO:2). Third, the intracellular domain was identified within residues from about 209 to about 411 in FIG. 1 (amino acid residues from about 158 to about 360 in SEQ ID NO:2). Importantly, the intracellular domain includes a death domain at residues from about 324 to about 391 (amino acid residues from about 273 to about 340 in SEQ ID NO:2). Further preferred fragments of the polypeptide shown in FIG. 1 include the mature protein from residues about 52 to about 411 (amino acid residues from about 1 to about 360 in SEQ ID NO:2), and soluble polypeptides comprising all or part of the extracellular and intracellular domains but lacking the transmembrane domain.

[0192] The invention further provides DR5 polypeptides encoded by the deposited cDNA including the leader and DR5 polypeptide fragments selected from the mature protein, the extracellular domain, the transmembrane domain, the intracellular domain, the death domain, and all combinations thereof

[0193] In addition, proteins of the invention can be chemically synthesized using techniques known in the art (e.g., see Creighton, 1983, Proteins: Structures and Molecular Principles, W. H. Freeman & Co., N.Y., and Hunkapiller, M., et al., Nature 310:105-111 (1984)). For example, a peptide corresponding to a fragment of the DR5 polypeptides of the invention can be synthesized by use of a peptide synthesizer. Furthermore, if desired, nonclassical amino acids or chemical amino acid analogs can be introduced as a substitution or addition into the DR5 polypeptide sequence. Non-classical amino acids include, but are not limited to, to the D-isomers of the common amino acids, 2,4-diaminobutyric acid, a-amino isobutyric acid, 4-aminobutyric acid, Abu, 2-amino butyric acid, g-Abu, e-Ahx, 6-amino hexanoic acid, Aib, 2-amino isobutyric acid, 3-amino propionic acid, ornithine, norleucine, norvaline, hydroxyproline, sarcosine, citrulline, homocitrulline, cysteic acid, t-butylglycine, t-butylalanine, phenylglycine, cyclohexylalanine, b-alanine, fluoro-amino acids, designer amino acids such as b-methyl amino acids, Ca-methyl amino acids, Na-methyl amino acids, and amino acid analogs in general. Furthermore, the amino acid can be D (dextrorotary) or L (levorotary).

[0194] Non-naturally occurring variants may be produced using art-known mutagenesis techniques, which include, but are not limited to oligonucleotide mediated mutagenesis, alanine scanning, PCR mutagenesis, site directed mutagenesis (see, e.g., Carter et al., Nucl. Acids Res. 13:433 1 (1986); and Zoller et al., Nucl Acids Res. 10:6487 (1982)), cassette mutagenesis (see, e.g., Wells et al., Gene 34:315 (1985)), restriction selection mutagenesis (see, e.g., Wells et al., Philos. Trans. R. Soc. London SerA 317:415 (1986)).

[0195] The invention additionally, encompasses DR5 polypeptides which are differentially modified during or after translation, e.g., by glycosylation, acetylation, phosphorylation, amidation, derivatization by known protecting/blocking groups, proteolytic cleavage, linkage to an antibody molecule or other cellular ligand, etc. Any of numerous chemical modifications may be carried out by known techniques, including but not limited to, specific chemical cleavage by cyanogen bromide, trypsin, chymotrypsin, papain, V8 protease, NaBH₄, acetylation, formylation, oxidation, reduction, metabolic synthesis in the presence of tunicamycin; etc.

[0196] Additional post-translational modifications encompassed by the invention include, for example, e.g., N-linked or O-linked carbohydrate chains, processing of N-terminal or C-terminal ends), attachment of chemical moieties to the amino acid backbone, chemical modifications of N-linked or O-linked carbohydrate chains, and addition or deletion of an N-terminal methionine residue as a result of procaryotic host cell expression. The polypeptides may also be modified with a detectable label. such as an enzymatic, fluorescent, isotopic or affinity label to allow for detection and isolation of the protein.

[0197] Also provided by the invention are chemically modified derivatives of DR5 which may provide additional advantages such as increased solubility, stability and circulating time of the polypeptide, or decreased immunogenicity (see U.S. Pat. No. 4,179,337). The chemical moieties for derivitization may be selected from water soluble polymers such as polyethylene glycol, ethylene glycol/propylene glycol copolymers, carboxymethylcellulose, dextran, polyvinyl alcohol and the like. The polypeptides may be modified at random positions within the molecule, or at predetermined positions within the molecule and may include one, two, three or more attached chemical moieties.

[0198] The polymer may be of any molecular weight, and may be branched or unbranched. For polyethylene glycol, the preferred molecular weight is between about 1 kDa and about 100 kDa (the term about indicating that in preparations of polyethylene glycol, some molecules will weigh more, some less, than the stated molecular weight) for ease in handling and manufacturing. Other sizes may be used, depending on the desired therapeutic profile (e.g., the duration of sustained release desired, the effects, if any on biological activity, the ease in handling, the degree or lack of antigenicity and other known effects of the polyethylene glycol to a therapeutic protein or analog). For example, the polyethylene glycol may have an average molecular weight of about 200, 500, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10,000, 10,500, 11,000, 11,500, 12,000, 12,500, 13,000, 13,500, 14,000, 14,500, 15,000, 15,500, 16,000, 16,500, 17,000, 17,500, 18,000, 18,500, 19,000, 19,500, 20,000, 25,000, 30,000, 35,000, 40,000, 50,000, 55,000, 60,000, 65,000, 70,000, 75,000, 80,000, 85,000, 90,000, 95,000, or 100,000 kDa.

[0199] As noted above, the polyethylene glycol may have a branched structure. Branched polyethylene glycols are described, for example, in U.S. Pat. No. 5,643, 575; Morpurgo et al., Appl. Biochem. Biotechnol. 56:59-72 (1996), Vorobjev et al., Nucleosides Nucleotides 18:2745-2750 (1999), and Caliceti et al., Bioconjug. Chem. 10:638-646 (1999), the disclosures of each of which are incorporated herein by reference.

[0200] The polyethylene glycol molecules (or other chemical moieties) should be attached to the protein with consideration of effects on functional or antigenic domains of the protein. There are a number of attachment methods available to those skilled in the art, e.g., EP 0 401 384, herein incorporated by reference (coupling PEG to G-CSF), see also Malik et al., Exp. Hematol. 20:1028-1035 (1992) (reporting pegylation of GM-CSF using tresyl chloride). For example, polyethylene glycol may be covalently bound through amino acid residues via a reactive group, such as, a free amino or carboxyl group. Reactive groups are those to which an activated polyethylene glycol molecule may be bound. The amino acid residues having a free amino group may include lysine residues and the N-terminal amino acid residues; those having a free carboxyl group may include aspartic acid residues glutamic-acid residues and the C-terminal amino acid residue. Sulfhydryl groups may also be used as a reactive group for attaching the polyethylene glycol molecules. Preferred for therapeutic purposes is attachment at an amino group, such as attachment at the N-terminus or lysine group.

[0201] As suggested above, polyethylene glycol may be attached to proteins via linkage to any of a number of amino acid residues. For example, polyethylene glycol can be linked to a proteins via covalent bonds to lysine, histidine, aspartic acid, glutamic acid, or cysteine residues. One or more reaction chemistries may be employed to attach polyethylene glycol to specific amino acid residues (e.g. lysine, histidine, aspartic acid, glutamic acid, or cysteine) of the protein or to more than one type of amino acid residue (e.g., lysine, histidine, aspartic acid, glutamic acid, cysteine and combinations thereof) of the protein.

[0202] One may specifically desire proteins chemically modified at the N-terminus. Using polyethylene glycol as an illustration of the present composition, one may select from a variety of polyethylene glycol molecules (by molecular weight, branching, etc.), the proportion of polyethylene glycol molecules to protein (or peptide) molecules in the reaction mix, the type of pegylation reaction to be performed, and the method of obtaining the selected N-terminally pegylated protein. The method of obtaining the N-terminally pegylated preparation (i.e., separating this moiety from other monopegylated moieties if necessary) may be by purification of the N-terminally pegylated material from a population of pegylated protein molecules. Selective proteins chemically modified at the N-terminus modification may be accomplished by reductive alkylation which exploits differential reactivity of different types of primary amino groups (lysine versus the N-terminal) available for derivatization in a particular protein. Under the appropriate reaction conditions, substantially selective derivatization of the protein at the N-terminus with a carbonyl group containing polymer is achieved.

[0203] As indicated above, pegylation of the proteins of the invention may be accomplished by any number of means. For example, polyethylene glycol may be attached to the protein either directly or by an intervening linker. Linkerless systems for attaching polyethylene glycol to proteins are described in Delgado et al., Crit. Rev. Thera. Drug Carrier Sys. 9:249-304 (1992); Francis et al. Intern. J. of Hematol. 68:1-18 (1998); U.S. Pat. No. 4,002,531; U.S. Pat. No. 5,349,052; WO 95/06058; and WO 98/32466, the disclosures of each of which are incorporated herein by reference.

[0204] One system for attaching polyethylene glycol directly to amino acid residues of proteins without an intervening linker employs tresylated MPEG, which is produced by the modification of monmethoxy polyethylene glycol (MPEG) using tresylchloride (ClSO₂CH₂CF₃). Upon reaction of protein with tresylated MPEG, polyethylene glycol is directly attached to amine groups of the protein. Thus, the invention includes protein-polyethylene glycol conjugates produced by reacting proteins of the invention with a polyethylene glycol molecule having a 2,2,2-trifluoreothane sulphonyl group.

[0205] Polyethylene glycol can also be attached to proteins using a number of different intervening linkers. For example, U.S. Pat. No. 5,612,460, the entire disclosure of which is incorporated herein by reference, discloses urethane linkers for connecting polyethylene glycol to proteins. Protein-polyethylene glycol conjugates wherein the polyethylene glycol is attached to the protein by a linker can also be produced by reaction of proteins with compounds such as MPEG-succinimidylsuccinate, MPEG activated with 1,1-carbonyldiimidazole, MPEG-2,4,5-trichloropenylcarbonate, MPEG-p-nitrophenolcarbonate, and various MPEG-succinate derivatives. A number additional polyethylene glycol derivatives and reaction chemistries for attaching polyethylene glycol to proteins are described in WO 98/32466, the entire disclosure of which is incorporated herein by reference. Pegylated protein products produced using the reaction chemistries set out herein are included within the scope of the invention.

[0206] The number of polyethylene glycol moieties attached to each protein of the invention (i.e., the degree of substitution) may also vary. For example, the pegylated proteins of the invention may be linked, on average, to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 17, 20, or more polyethylene glycol molecules. Similarly, the average degree of substitution within ranges such as 1-3, 2-4, 3-5, 4-6, 5-7, 6-8, 7-9, 8-10, 9-11, 10-12, 11-13, 12-14, 13-15, 14-16, 15-17, 16-18, 17-19, or 18-20 polyethylene glycol moieties per protein molecule. Methods for determining the degree of substitution are discussed, for example, in Delgado et al., Crit. Rev. Thera. Drug Carrier Sys. 9:249-304 (1992).

[0207] As mentioned, DR5 polypeptides may be modified by either natural processes, such as posttranslational processing, or by chemical modification techniques which are well known in the art. It will be appreciated that the same type of modification may be present in the same or varying degrees at several sites in a given DR5 polypeptide. Also, a given DR5 polypeptide may contain many types of modifications. DR5 polypeptides may be branched, for example, as a result of ubiquitination, and they may be cyclic, with or without branching. Cyclic, branched, and branched cyclic DR5 polypeptides may result from posttranslation natural processes or may be made by synthetic methods. Modifications include acetylation, acylation, ADP-ribosylation, amidation, covalent attachment of flavin, covalent attachment of a heme moiety, covalent attachment of a nucleotide or nucleotide derivative, covalent attachment of a lipid or lipid derivative, covalent attachment of phosphotidylinositol, cross-linking, cyclization, disulfide bond formation, demethylation, formation of covalent cross-links, formation of cysteine, formation of pyroglutamate, formylation, gamma-carboxylation, glycosylation, GPI anchor formation, hydroxylation, iodination, methylation, myristoylation, oxidation, pegylation, proteolytic processing, phosphorylation, prenylation, racemization, selenoylation, sulfation, transfer-RNA mediated addition of amino acids to proteins such as arginylation, and ubiquitination. (See, for instance, PROTEINSSTRUCTURE AND MOLECULAR PROPERTIES, 2nd Ed., T. E. Creighton, W. H. Freeman and Company, New York (1993); POSTTRANSLATIONAL COVALENT MODIFICATION OF PROTEINS, B. C. Johnson, Ed., Academic Press, New York, pgs. 1-12 (1983); Seifter et al., Meth Enzymol 182:626-646 (1990); Rattan et al., Ann NY Acad Sci 663:48-62 (1992)).

[0208] The DR5 polypeptides can be recovered and purified from chemical synthesis and recombinant cell cultures by standard methods which include, but are not limited to, ammonium sulfate or ethanol precipitation, acid extraction, anion or cation exchange chromatography, phosphocellulose chromatography, hydrophobic interaction chromatography, affinity chromatography, hydroxylapatite chromatography and lectin chromatography. Most preferably, high performance liquid chromatography (HPLC) is employed for purification. Well known techniques for refolding protein may be employed to regenerate active conformation when the polypeptide is denatured during isolation and/or purification.

[0209] DR5 polynucleotides and polypeptides may be used in accordance with the present invention for a variety of applications, particularly those that make use of the chemical and biological properties of DR5. Among these are applications in the treatment and/or prevention of tumors, parasitic infections, bacterial infections, viral infections, restenosis, and graft vs. host disease; to induce resistance to parasites, bacteria and viruses; to induce proliferation of T-cells, endothelial cells and certain hematopoietic cells; to regulate anti-viral responses; and to treat and/or prevent certain autoimmune diseases after stimulation of DR5 by an agonist. Additional applications relate to diagnosis, treatment, and/or prevention of disorders of cells, tissues and organisms. These aspects of the invention are discussed further below.

[0210] The present invention encompasses polypeptides comprising, or alternatively consisting of, an epitope of the polypeptide having an amino acid sequence of SEQ ID NO:2, or an epitope of the polypeptide sequence encoded by a polynucleotide sequence contained in the cDNA deposited as ATCC Deposit No. 97920 or encoded by a polynucleotide that hybridizes to the complement of the sequence of SEQ ID NO:1 or contained in the cDNA deposited as ATCC Deposit No. 97920 under stringent hybridization conditions or lower stringency hybridization conditions as defined supra. The present invention further encompasses polynucleotide sequences encoding an epitope of a polypeptide sequence of the invention (such as, for example, the sequence disclosed in SEQ ID NO:1), polynucleotide sequences of the complementary strand of a polynucleotide sequence encoding an epitope of the invention, and polynucleotide sequences which hybridize to the complementary strand under stringent hybridization conditions or lower stringency hybridization conditions defined supra.

[0211] In another aspect, the invention provides a peptide or polypeptide comprising an epitope-bearing portion of a polypeptide described herein. The epitope of this polypeptide portion is an immunogenic or antigenic epitope of a polypeptide of the invention. The term epitopes, as used herein, refers to portions of a polypeptide having antigenic or immunogenic activity in an animal, preferably a mammal, and most preferably in a human. In a preferred embodiment, the present invention encompasses a polypeptide comprising an epitope, as well as the polynucleotide encoding this polypeptide. An immunogenic epitope is defined as a part of a protein that elicits an antibody response when the whole protein is the immunogen. On the other hand, a region of a protein molecule to which an antibody can bind is defined as an antigenic epitope. The number of immunogenic epitopes of a protein generally is less than the number of antigenic epitopes. See, for instance, Geysen et al., Proc. Natl. Acad. Sci. USA 81:3998-4002 (1983).

[0212] Fragments that function as epitopes may be produced by any conventional means. (See, e.g., Houghten, Proc. Natl. Acad. Sci. USA 82:5131-5135 (1985), further described in U.S. Pat. No. 4,631,211).

[0213] As to the selection of peptides or polypeptides bearing an antigenic epitope (i. e., that contain a region of a protein molecule to which an antibody can bind), it is well known in that art that relatively short synthetic peptides that mimic part of a protein sequence are routinely capable of eliciting an antiserum that reacts with the partially mimicked protein. See, for instance, Sutcliffe, J. G., Shinnick, T. M., Green, N. and Learner, R. A., Antibodies That React With Predetermined Sites on Proteins, Science 219:660-666 (1983). Peptides capable of eliciting protein-reactive sera are frequently represented in the primary sequence of a protein, can be characterized by a set of simple chemical rules, and are confined neither to immunodominant regions of intact proteins (i.e., immunogenic epitopes) nor to the amino or carboxyl terminals.

[0214] Non-limiting examples of antigenic polypeptides or peptides that can be used to generate DR5-specific antibodies include: a polypeptide comprising, or alternatively consisting of, amino acid residues from about 62 to about 110 in FIG. 1 (about 11 to about 59 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, amino acid residues from about 119 to about 164 in FIG. 1 (about 68 to about 113 in SEQ ID NO:2); a polypeptide comprising, or alternatively consisting of, amino acid residues from about 224 to about 271 in FIG. 1 (about 173 to about 220 in SEQ ID NO:2); and a polypeptide comprising, or alternatively consisting of, amino acid residues from about 275 to about 370 in FIG. 1 (about 224 to about 319 in SEQ ID NO:2). As indicated above the inventors have determined that the above polypeptide fragments are antigenic regions of the DR5 protein.

[0215] The epitope-bearing peptides and polypeptides of the invention may be produced by any conventional means Hougthen, R. A., General Method for the Rapid Solid-Phase Synthesis of Large Numbers of Peptides: Specificity of Antigen-Antibody Interaction at the Level of Individual Amino Acids, Proc. Natl. Acad. Sci. USA 82:5131-5135 (1985). This Simultaneous Multiple Peptide Synthesis (SMPS) process is further described in U.S. Pat. No. 4,631,211 to Hougthen et al. (1986). As one of skill in the art will appreciate, DR5 polypeptides of the present invention and the epitope-bearing fragments thereof described above can be combined with parts of the constant domain of immunoglobulins (IgG), resulting in chimeric polypeptides. These fusion proteins facilitate purification and show an increased half-life in vivo. This has been shown, e.g., for chimeric proteins consisting of the first two domains of the human CD4-polypeptide and various domains of the constant regions of the heavy or light chains of mammalian immunoglobulins (EPA 394,827; Traunecker et al., Nature 331:84-86 (1988)). Fusion proteins that have a disulfide-linked dimeric structure due to the IgG part can also be more efficient in binding and neutralizing other molecules than the monomeric DR5 protein or protein fragment alone (Fountoulakis et al., J Biochem. 270:3958-3964 (1995)).

[0216] Antibodies

[0217] The present invention further relates to antibodies and T-cell antigen receptors (TCR) which immunospecifically bind a polypeptide, preferably an epitope, of the present invention (as determined by immunoassays well known in the art for assaying specific antibody-antigen binding). Antibodies of the invention include, but are not limited to, polyclonal, monoclonal, multispecific, human, humanized or chimeric antibodies, single chain antibodies, Fab fragments, F(ab) fragments, fragments produced by a Fab expression library, anti-idiotypic (anti-Id) antibodies (including, e.g., anti-Id antibodies to antibodies of the invention), and epitope-binding fragments of any of the above. The term antibody, as used herein, refers to immunoglobulin molecules and immunologically active portions of immunoglobulin molecules, i.e., molecules that contain an antigen binding site that immunospecifically binds an antigen. The immunoglobulin molecules of the invention can be of any type (e.g., IgG, IgE, IgM, IgD, IgA and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) or subclass of immunoglobulin molecule.

[0218] Most preferably the antibodies are human antigen-binding antibody fragments of the present invention and include, but are not limited to, Fab, Fab and F(ab)2, Fd, single-chain Fvs (scFv), single-chain antibodies, disulfide-linked Fvs (sdFv) and fragments comprising either a V_L or V_H domain. Antigen-binding antibody fragments, including single-chain antibodies, may comprise the variable region(s) alone or in combination with the entirety or a portion of the following: hinge region, CH1, CH2, and CH3 domains. Also included in the invention are antigen-binding fragments also comprising any combination of variable region(s) with a hinge region, CH1, CH2, and CH3 domains. The antibodies of the invention may be from any animal origin including birds and mammals. Preferably, the antibodies are human, murine, donkey, ship rabbit, goat, guinea pig, camel, horse, or chicken. As used herein, human antibodies include antibodies having the amino acid sequence of a human immunoglobulin and include antibodies isolated from human immunoglobulin libraries or from animals transgenic for one or more human immunoglobulin and that do not express endogenous immunoglobulins, as described infra and, for example in, U.S. Pat. No. 5,939,598 by Kucherlapati et al.

[0219] The antibodies of the present invention may be monospecific, bispecific, trispecific or of greater multispecificity. Multispecific antibodies may be specific for different epitopes of a polypeptide of the present invention or may be specific for both a polypeptide of the present invention as well as for a heterologous epitope, such as a heterologous polypeptide or solid support material. See, e.g., PCT publications WO 93/17715; WO 92/08802; WO 91/00360; WO 92/05793; Tutt et al., J. Immunol. 147:60-69 (1991); U.S. Pat. Nos. 4,474,893; 4,714,681; 4,925,648; 5,573,920; 5,601,819; Kostelny et al., J. Immunol. 148:1547-1553 (1992).

[0220] Antibodies of the present invention may be described or specified in terms of the epitope(s) or portion(s) of a polypeptide of the present invention that they recognize or specifically bind. The epitope(s) or polypeptide portion(s) may be specified as described herein, e.g., by N-terminal and C-terminal positions, by size in contiguous amino acid residues, or listed in the Tables and Figures. Antibodies that specifically bind any epitope or polypeptide of the present invention may also be excluded. Therefore, the present invention includes antibodies that specifically bind polypeptides of the present invention, and allows for the exclusion of the same.

[0221] Antibodies of the present invention may also be described or specified in terms of their cross-reactivity. Antibodies that do not bind any other analog, ortholog, or homolog of a polypeptide of the present invention are included. Antibodies that bind polypeptides with at least 95%, at least 90%, at least 85%, at least 80%, at least 75%, at least 70%, at least 65%, at least 60%, at least 55%, and at least 50% identity (as calculated using methods known in the art and described herein) to a polypeptide of the present invention are also included in the present invention. Antibodies that do not bind polypeptides with less than 95%, less than 90%, less than 85%, less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, and less than 50% identity (as calculated using methods known in the art and described herein) to a polypeptide of the present invention are also included in the present invention. Further included in the present invention are antibodies that bind polypeptides encoded by polynucleotides which hybridize to a polynucleotide of the present invention under stringent hybridization conditions (as described herein). Antibodies of the present invention may also be described or specified in terms of their binding affinity to a polypeptide of the invention. Preferred binding affinities include those with a dissociation constant or Kd less than 510²M, 10²M, 510³M, 10³M, 510⁴M, 10⁴M, 510⁵M, 10⁵M, 510⁶M, 10⁶M, 510⁷M, 10⁷M, 510⁸M, 10⁸M, 510⁹M, 10⁹M, 510¹⁰M, 10¹⁰M, 510¹¹M, 10¹¹M, 510¹²M, 10¹²M, 510¹³M, 10¹³M, 510¹⁴M, 10¹⁴M, 510¹⁵M, and 10¹⁵M.

[0222] The invention also provides antibodies that competitively inhibit binding of an antibody to an epitope of the invention as determined by any method known in the art for determining competitive binding, for example, the immunoassays described herein. In preferred embodiments, the antibody competitively inhibits binding to the epitope by at least 90%, at least 80%, at least 70%, at least 60%, or at least 50%.

[0223] Antibodies of the present invention may act as agonists or antagonists of the polypeptides of the present invention. For example, the present invention includes antibodies which disrupt the receptor/ligand interactions with the polypeptides of the invention either partially or fully. The invention features both receptor-specific antibodies and ligand-specific antibodies. The invention also features receptor-specific antibodies which do not prevent ligand binding but prevent receptor activation. Receptor activation (i.e., signaling) may be determined by techniques described herein or otherwise known in the art. For example, receptor activation can be determined by detecting the phosphorylation (e.g., tyrosine or serine/threonine) of the receptor or its substrate by immunoprecipitation followed by western blot analysis (for example, as described supra). In specific embodiments, antibodies are provided that inhibit ligand or receptor activity by at least 90%, at least 80%, at least 70%, at least 60%, or at least 50% of the activity in absence of the antibody.