RETINOID RECEPTOR COMPOSITIONS AND METHODS

Abstract: The present invention relates to novel receptor polypeptides, which, upon interaction with certain ligands, or activation by certain compounds, modulate transcription of certain genes by binding to cognate response elements associated with promoters of such genes. The novel receptors of the invention modulate transcription in the presence of retinoid compounds. The receptors of the present invention differ significantly from known retinoid acid receptors, in protein primary sequence and in responsiveness to exposure to various retinoids. The invention provides DNAs encoding the novel receptors, expression vectors for expression of the receptors, cells transformed with such expression vectors, cells co-transformed with such expression vectors and with reporter vectors to monitor modulation of transcription by the receptors, and methods of using such co-transformed cells in screening for compounds which are capable, directly or indirectly, of activating the receptors. The invention also provides nucleic acid probes for identifying DNAs which encode additional retinoid receptors of the same class as the novel receptors disclosed herein.

Description: RETINOID RECEPTOR COMPOSITIONS AND METHODS RELATED APPLICATIONS This application is a continuation-in-part of application Serial No. 478,071, filed February 9, 1990, now pending, the entire contents of which are hereby incorporated by reference herein. TECHNICAL FIELD The present invention concerns novel, steroid hormone-like receptor proteins and methods of making and using same. More particularly, the invention relates to steroid hormone-like receptor proteins with transcription- modulating effects. Such proteins are responsive to the presence of retinoid acid and other vitamin A metabolites. BACKGROUND OF THE INVENTION The retinoids comprise a group of compounds including retinoid acid, retinol (vitamin A) , and a series of natural and synthetic derivatives that together exert profound effects on development and differentiation in a wide variety of systems. Although early studies focused on the effects " of retinoids on growth and differentiation of epithelial cells, their actions have been shown to be widespread. Many recent studies have examined the effects of these molecules on a variety of cultured neoplastic cell types, including the human promyelocytic leukemia cell line, HL60, where retinoid acid appears to be a potent inducer of granulocyte differentiation. In F9 embryonal carcinoma cells, retinoid acid will induce the differentiation of parietal endoderm, characteristic of a late mouse blastocyst. Retinoid acid also appears to play an important role in defining spatio-temporal axes in the developing avian limb and the regenerating amphibian limb. Retinoid acid has been shown to induce the transcription of several cDNAs whose gene products have been isolated by differential screening. This observation supports the hypothesis that retinoid acid exerts its action via modulation of gene expression, in a manner analogous to the way in which steroid and thyroid hormones influence their target genes. The ability to identify compounds which affect transcription of genes which are responsive to retinoid acid or other metabolites of vitamin A, would be of significant value, e.g., " for therapeutic applications. Further, systems useful for monitoring solutions, body fluids and the like for the presence of retinoid acid, vitamin A or metabolites of the latter would be of value in various analytical biochemical applications and, potentially, medical diagnosis. Through molecular cloning studies it has been possible to demonstrate that receptors for steroid, retinoid and thyroid hormones are all structurally related. These receptors comprise a superfa ily of regulatory proteins that are capable of modulating specific gene expression in response to hormone stimulation by binding directly to ciε-acting elements (Evans, Science 240, 889 (1988) ; Green and Chambon, Trends genet. 4, 309 (1988)). Structural comparisons and functional studies with mutant receptors have established that these molecules are composed of discrete functional domains, most notably, a DNA-binding domain that is composed typically of 66 - 68 amino acids (including two zinc fingers) , and an associated carboxy terminal stretch of approximately 250 amino acids which comprises the ligand-binding domain (reviewed in Evans, supra) . Low-stringency hybridization has permitted the isolation and subsequent delineation of a growing list of gene products which possess the structural features of hormone receptors. Recently, a retinoid acid dependent transcription factor, referred to as RAR-alpha (retinoid acid receptor- alpha) , has been identified. Subsequently, two additional RAR-related genes have been isolated; thus there are now at least three different RAR subtypes (alpha, beta and gamma) known to exist in mice and humans. These retinoid acid receptors (RARs) share homology with the superfamily of steroid hormone and thyroid hormone receptors and have been shown to regulate specific gene expression by a similar ligand-dependent mechanism (U esono et al.. Nature 336, 262 (1988)). These RAR subtypes are expressed in distinct patterns throughout development and in the mature organism. Other information helpful in the understanding and practice of the present invention can be found in commonly assigned, co-pending United States Patent Application Serial Nos. 108,471, filed October 20, 1987; 276,536, filed November 30, 1988; 325,240, filed March 17, 1989; 370,407, filed June 22, 1989; and 438,757, filed November 16, 1989, all of which are hereby incorporated herein by reference in their entirety. SUMMARY OF THE INVENTION We have discovered novel receptors which are activated to modulate transcription of certain genes in animal cells, when the cells are exposed to retinoids, such as retinoid acid and retinal. The novel receptors differ significantly from known retinoid acid receptors, both in terms of the primary protein sequence and responsiveness to various retinoids. The novel receptors have several isoforms located at genetically distinct loci. They are capable of transactivating through cis elements similar to retinoid acid receptors, but show a different rank potency and dose dependency to retinoids. Northern analyses of the novel receptors of the present invention indicate that each isoform has a unique pattern of expression in adult tissue and is temporally and spatially expressed in the embryo. Binding experiments demonstrate that the novel receptor proteins have a low affinity for [ 3 H]retinoic acid. These results, taken together with results from transactivation studies,, suggest the ligand(s) for the novel receptors is a metabolite(s) or structural analog(s) of retinoic acid. The invention provides DNAs encoding novel receptors, expression vectors for expression of the receptors, cells transformed with such expression vectors, cells co-transformed with such expression vectors and reporter vectors to monitor modulation of transcription by the receptors, and methods of using such co-transformed cells in screening for compounds which are capable, directly or indirectly, of activating the receptors. The invention also provides single-stranded nucleic acid probes for identifying DNAs encoding additional retinoid receptors. The invention also provides a method for making the receptors of the invention by expressing DNAs which encode the receptors in suitable host organisms. Animal cells in which receptors of the invention are present can be employed to assay fluids for the presence of retinoids. Animal cells of the invention can also be employed to screen compounds of potential therapeutic value for their ability to bind and/or promote trans¬ activation (i.e., trans-acting transcriptional activation) by the receptors of the invention. As will be described in greater detail below, the receptors of the invention modulate transcription of genes. This occurs upon binding of receptor to hormone response elements, which are positioned operatively, with respect to promoters for such genes, for such modulation to occur. Among hormone response elements contemplated for use in the practice τ>f the present invention are TRE , the beta-retinoid acid response element, and the estrogen response element, as well as closely related elements which are disclosed, for example, in Application Serial No. 438,757, filed November 16, 1989, and Application Serial No. 325,240, filed March 17, 1989. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows the extent of amino acid identity (i.e., "homology") between the DNA binding domain ("DNA") and ligand binding domain ("RX") of mouse RXR-alpha (mRXRα) , relative to the corresponding domains of human retinoic acid receptor-a pha (hRAR ) , human estrogen receptor (hER) , human thyroid hormone receptor-beta (hTR/?) and human glucocorticoid receptor (hGR) . Figure 2 shows the extent of amino acid identity (i.e., "homology") between the DNA binding domain ("DNA") and ligand binding domain ("LIGAND") of human RXR-alpha (hRARα) , relative to the corresponding domains of human retinoic acid receptor-beta (hRARø) , human retinoic acid receptor-gamma (IRAR 7 ) , hTR3 and hRXRα. Figure 3 shows the extent o amino acid identity (i.e., "homology") between the DNA binding domain ("DNA") and ligand binding domain ("RX") of mRXRβ, relative to the corresponding domains of mouse RXR-beta (mRXR£) , mouse RXR-gamma (mRXR ) and hRXRα. Figure 4 illustrates the production of CAT from the reporter vector (ADH-TREfp-CAT) in Drosophila melanogaster Schneider line 2 cells, which are co-transformed with receptor expression vector A5C-RXR-alpha and are in a medium containing various concentrations of retinoic acid. Figure 5 illustrates the differences in transcription-activating activities of hRXR-alpha and hRAR-alpha, in mammalian cells in culture containing different vitamin A metabolites. Figure 6, like Figure 5, illustrates the differences in transcription-activating activities of hRXR-alpha and hRAR-alpha in mammalian cells in culture containing retinoic acid or different synthetic retinoids. Figure 7 illustrates the differences between hRXR- alpha and hRAR-alpha in dose-response to retinoic acid in media bathing mammalian cells in which the receptors occur. Figure 8 illustrates the differences between mouse RXR-alpha (mRXRα) , mouse RXR-beta (mRXRϊ) and mouse RXR-gamma ( RXR ) in dose response to retinoid acid (RA) in media bathing mammalian cells expressing such receptors. Figure 9 illustrates the differences between mRXRα, mRXR3 and mRXR in dose response to 3,4-didehydroretinoic acid (ddRA) in media bathing mammalian cells expressing such receptors. DETAILED DESCRIPTION OF THE INVENTION The invention concerns novel polypeptides, which are characterized by: (1) being responsive to the presence of retinoid(s) to regulate transcription of associated gene(s) ; (2) having a DNA binding domain of about 66 amino acids with 9 Cys residues, wherein said DNA binding domain has: (a) less than about 65 % amino acid identity with the DNA binding domain of hRAR-alpha, (b) less than about 55 % amino acid identity with the DNA binding domain of hTR-beta, and (c) less than about 55 % amino acid identity with the DNA binding domain of hGR; and (3) not including the sequence set forth in Sequence ID No 7. The novel polypeptide receptors of the present invention can be further characterized in a variety of ways, e.g., by increasing the rate of transcription of a target gene in a construct comprising a promoter operatively linked to a hormone response element for transcriptional activation by said receptors, relative to the rate of transcription in the absence of said receptor and/or in the absence of retinoic acid and retinal. Transcription of said target gene is measured in an animal cell in culture, the medium of which comprises retinoid acid or retinal at a concentration greater than about 5 x 10 '7 M. Alternatively, the polypeptide receptors of the present invention can -be further characterized as being encoded by a continuous nucleotide sequence which encodes substantially the same amino acid sequence as that of amino acids 1-462 shown in Sequence ID No. 2 [hRXRα], amino acids 1-467 shown in Sequence ID No. 4 [mRXRα], or amino acids 1-463 shown in Sequence ID No. 6 [mRXRγ]. As yet another alternative, the polypeptide receptors of the present invention can be characterized as being encoded by a continuous nucleotide sequence which encodes substantially the same amino acid sequence as that of amino acids 135-200 shown in Sequence ID No. 2 [DNA binding domain of hRXRα], amino acids 140-205 shown in Sequence ID No. 4 [DNA binding domain of mRXRα], or amino acids 139-204 shown in Sequence ID No. 6 [DNA binding domain of mRXR ]. As still another alternative, the polypeptide receptor of the present invention can be characterized as being encoded by a continuous nucleotide sequence which is substantially the same as nucleotides 76-1464 shown in Sequence ID No. 1 [hRXRα], nucleotides 181-1581 shown in Sequence ID No. 3 [mRXRα], or nucleotides 123-1514 shown in Sequence ID No. 3 [E1RXR 7 ]. As employed herein, the term "retinoids" refers to naturally occurring compounds with vitamin A activity synthetic analogs and various metabolites thereof. The retinoids are a class -of compounds consisting of four isoprenoid units joined in head-to-tail manner. Numerous retinoids have been identified, as described, for example, by Sporn, Roberts and Goodman in the two volume treatise entitled The Retinoids (Academic Press, NY, 1984) , to which the reader is directed for further detail. Exemplary retinoids include retinol, retinyl acetate, retinyl hexadecanoate, α-retinyl, 4,14- retroretinol, deoxyretinol, anhydroretinol, 3,4- didehydroretinol, 15,15-dimethyl retinol, retinyl methyl ether, retinyl phosphate, mannosyl retinyl phosphate, retinol thioacetate, retinal (retinaldehyde) , 3,4- didehydroretinal, retinylidene acetylacetone, retinylidene-l,3-cyclopentanedione, retinal oxime, retinaldehyde acetylhydrazone, retinoic acid, 4-hydroxyretinoic acid, 4-oxoretinoic acid, 5,6-dihydroretinoic acid, 5,6-epoxyretinoic acid, 5,8-epoxyretinoic acid, the open-chain C 20 analog of retinoid acid (i.e., (all-£-3,7,11,15-tetramethy1-2,4,6, 8,10, 2,14-hexadecaheptaenoic acid), 7,8- didehydroretinoic acid, 7,8-dihydroretinoic acid, "C 15 Acid" (E_, E.)-3-methyl-5-(2,6,6-trimethyl-2-cyclohexen-l- yl)-2,4-pentanedioic acid), "C 17 Acid" ( (E,£,l)-5-methyl- 7-(2,6,6-trimethyl-l-cyclohexen-l-yl)-2,4,6-hepatrienoic acid), "C 22 Acid" (14 » -apo-/3, ^-carotenoic acid), retinoic acid esters (e.g., methyl ester, ethyl ester, etc.), retinoid acid ethylamide, retinoic acid 2- hydroxyethylamide, methyl retinone, "C 18 " Ketone" ((£,1, E)-6-methyl-8-(2,6,6-trimethyl-l-cyclohexen-l-yl)-3,5,7- ocatrien-2-one) , and the like. In addition, according to the present invention, there are provided DNA sequences which encode novel polypeptides as described above. Further in accordance with the present invention, there are provided DNA constructs which are operative in animal cells in culture to make said polypeptides. According to a still further embodiment of the present invention, there are provided animal cells in culture which are transformed with DNA constructs (as described above) , which are operative in said cells to make receptor polypeptides, by expression of DNA segments which encode the above described polypeptides. Among the animal cells contemplated for use in the practice of the present nvention are those which are further transformed with a reporter vector which comprises: (a) a promoter that is operable in the cell, (b) a hormone response element, and (c) a DNA segment encoding a reporter protein, wherein said reporter protein-encoding DNA segment is operatively linked to said promoter for transcription of said DNA segment, and wherein said hormone response element is operatively linked to said promoter for activation thereof. In accordance with the present invention, there is also provided a method of testing a compound for its ability to regulate the transcription-activating properties of the above- " described receptor polypeptides, which method comprises assaying for the presence or absence of reporter protein upon contacting of cells containing a reporter vector and receptor polypeptide with said compound; wherein said reporter vector and said receptor polypeptide are as described above. In accordance with a still further embodiment of the present invention, there are provided various probes, which can be used to identify genes encoding receptors related to those of the present invention. In this regard, particular reference is made to Examples V and VI below. More particularly, the invention provides labeled, single-stranded nucleic acids comprising sequences of at least 20 contiguous bases having substantially the same sequence as any 20 or more contiguous bases selected from: (i) bases 2 - 1861, inclusive, of the DNA illustrated in Sequence ID No. 1 [hRXR-α], or (ii) bases 20 - 2095, inclusive, of the DNA illustrated in Sequence ID No. 2 [mRXR-α] , or (iii) bases 15 - 1653, inclusive, of the DNA illustrated in Sequence ID No. 3 [mRXR-7], or (iv) the complement of any one of the sequences according to (1) , (ii) , or (iii) . As employed herein, the term "labeled single- stranded nucleic acid sequences" refers to single- stranded DNA or RNA sequences which have been modified by the addition thereto of a species which renders the "labeled" sequence readily detectable from among other unmodified sequences. Exemplary labels include radioactive label (e.g., 32 P, 35 S) , enzymatic label (e.g., biotin) , and the like. Preferred probes contemplated for use in the practice of the present invention are those having at least about 100 contiguous bases selected from the above- described sequences. Especially preferred are probes having in the range of about 198 up to several hundred nucleotides, because greater selectivity is afforded by longer sequences. The invention also encompasses a method of making the above-described receptor polypeptides, which method comprises culturing suitable host cells which are transformed with an expression vector operable in said cells to express DNA which encodes receptor polypeptide. Suitable hosts contemplated for use in the practice of the present invention include yeast, bacteria, mammalian cells, insect cells, and the like. E. coli is the presently preferred bacterial species. Any of a number of expression vectors are well known to those skilled in the art that could be employed in the method of the invention. Among these are the prokaryotic expression vectors pNH8A, pNH16A and pNH18A available from Stratagene, La Jolla, California USA. Further information on the invention is provided in the following non-limiting examples and description of an exemplary deposit. EXAMPLES Example I The KpnI/SacI restriction fragment (503bp) including the DNA-binding domain of hRAR-alpha-encoding DNA [See Giguere et al.. Nature 330, 624 (1987) ; and commonly assigned United States Patent Application Serial No. 276,536, filed November 30, 1988; and European Patent Application Publication No. 0 325 849, all incorporated herein by reference] was nick-translated and used to screen a lambda-gtll human liver cDNA library (Kwok et al.,Biochem. 24, 556 (1985)) at low stringency. The hybridization mixture contained 35% formamide, IX Denhardt's, 5X SSPE (IX SSPE=0.15 M NaCl, lOmM Na 2 HP0 4 ImM EDTA) , 0.1% SDS, 10% dextran sulf te, 100 g/ml denatured salmon sperm DNA and 10 6 cpm of [^P]-labelled probe. Duplicate nitrocellulose filters were hybridized for 16h at 42°C, washed once at 25°C for 15 in with 2X SSC (IX SSC=0.15 M NaCl, 0.015 M sodium citrate), 0.1% SDS and then washed twice at 55°C for 30 min. in 2X SSC, 0.1% SDS. The filters were autoradiographed for 3 days at -70°C using an intensifying screen. Positive clones were isolated, subcloned into pGEM vectors (Promega, Madison, Wisconsin, USA), restriction mapped, and re-subcloned in various sized restriction fragments into M13mpl8 and M13mpl9 sequencing vectors. DNA sequence was determined by the dideoxy method with Sequenase* sequencing kit (United States Biochemical, Cleveland, Ohio, USA) and analyzed by University of Wisconsin Genetics Computer Group programs (Devereux et al., Nucl. Acids Res. 12., 387 (1984)). A unique receptor-like sequence was identified and designated lambda-HL3-l. Λ Lambda-HL3-1 was used as a hybridization probe to rescreen a lambda-gtlO human kidney cDNA library (Arriza et al., Science 237, 268 (1987)) which produced several clones, the longest of which was sequenced and designated lambda-XR3-l. The DNA sequence obtained as an EcoRI- fragment from lambda-XR3-l has the sequence indicated in Sequence ID No. 1 [hRXRα]. Similar screening of a mouse whole embryo library with the full-length hRXR-alpha clone described above provided additional sequences which encode different isoforms of the human RXR-alpha receptor. In addition, the mouse homolog (mouse RXR-alpha) was also identified in this way. Thus, mRNA was isolated from 14.5 day post-coitus (p.c.) mouse embryos, translated into cDNA, linkered with EcoRI/NotI linkers, then inserted into the unique EcoRI site of the cloning vector λ-ZAP (Stratogene) . The resulting library was screened at reduced stringency with 32 P-labeled, full length hRXR-alpha as the probe. The DNA sequences of the resulting clones are set forth as Sequence ID No. 3 [mRXRα] and Sequence ID No. 5 [ RXR 7 ]. Example II Amino acid sequences of mRXR-alpha, hRAR-alpha (human retinoic acid receptor-alpha) , hER (human estrogen receptor) hTR-beta (human thyroid hormone receptor-beta) and hGR (human glucocorticoid receptor) were aligned using the University of Wisconsin Genetics Computer Group program "Bestfit" (Devereux et al., supra). Regions of significant similarity between mRXR-alpha and the other receptors, i.e., the 66 - 68 amino acid DNA binding domains and the ligand-binding domains, are presented schematically in Figure 1 as percent amino acid identity. Similarly, the amino acid sequences of human RAR- alpha (hRARα) , human RAR-beta (hRARø) , human RAR-gam a (hRAR 7 ) , human TR-beta (hTR£) and human RXR-alpha (hRXRα) were aligned. As done in Figure 1, regions of significant similarity between hRAR-alpha and the other receptors are presented schematically in Figure 2 as percent amino acid identity. A further comparison of receptors is set forth in Figure 3. Thus, the amino acid sequences of mouse RXR- alpha (mRXRα) , mouse RXR-beta (mRXR,9) , mouse RXR-gam a (m XR 7 ) and human RXR-alpha (hRXRα) were aligned, and the percent amino acid identity presented schematically in Figure 3. Although the DNA-binding domains of both mRXR-alpha and hRXR-alpha are conserved relatively well with respect to other receptors (such as hRAR-alpha and hTR-beta) , the ligand binding domain is poorly conserved. (See Figures 1 and 3) . A comparison between the retinoic acid receptor subfamily of receptors and hRXR-alpha reveals nothing to suggest that hRXR-alpha is related to any of the known retinoid receptors (Fig. 2) . Example III Drosophila melanogaster Schneider line 2 ("S2") cells (Schneider, Embryol. Exp. Morphol. 27, 353 (1972), which are readily available, were seeded at 2 x 10 6 per 35 mm 2 culture dish and maintained in Schneider medium (GIBCO/Life Technologies, Inc., Grand Island, New York, USA) supplemented with penicillin, streptomycin and 12% heat-inactivated fetal bovine serum (Irvine Scientific, Santa Ana, California, USA) . The cells were transiently co-transfected with 10 μg/dish of plasmid DNA by calcium phosphate precipitation (Krasnow et al.. Cell 57, 1031 (1989): 4.5 μg/dish of receptor expression vector or control construct (producing no hRXR-alphaJ ; 0.5 μg/dish of reporter plasmid or control reporter plasmid; 0.5 μg/dish of reference plasmid; and 4.5 μg inert plasmid DNA. In the receptor expression vector, A5C-RXR-alpha (4.5 μg/dish), receptor hRXR-alpha is constitutively expressed in the S2 cells under the control of the Drosophila actin 5C promoter (A5C; Thummel et al.. Gene 74: 445 (1988) ) driving transcription of the EcoRI-site- bounded insert of lambda-XR3-l. In the control vector, A5C-RXR rev (also 4.5 μg/ml) , the EcoRI-site-bounded insert from lambda-XR3-l is inserted in the reverse (i.e., non- coding or non-sense-coding) orientation. A5C-RXR-alpha was made by first inserting at the unique BamHI site of A5C a linker of sequence: 5•-GATCCGATATCCATATGGAATTCGGTACCA, and then inserting, at the EcoRI site of the linker (underlined above) , the EcoRI-site-bounded insert of lambda-XR3-l (See Example I) . The reporter plasmid ADH-TRE -CAT (at 0.5 μg/dish) contains the palindromic thyroid hormone response element TREp, having the sequence: 5•-AGGTCATGACCT [(Glass et al. Cell 54, 313 (1988); Thompson and Evans, Proc. Natl. Acad. Sci. (USA) 86, 3494 (1989)], inserted into position -33 (with respect to the transcription start site) of a pD33-ADH-CAT background (Krasnow et al., Cell 57, 1031 (1989)). pD33-ADH-CAT is a plasmid with the distal promoter of the Drosophila melanogaster alcohol dehydrogenase gene linked operably for transcription to the bacterial (E. coli) chloramphenicor acetyltransferase ("CAT") gene, a gene for the indicator protein CAT. ADH-TREp-CAT was made by inserting the oligonucleotide of sequence: 5 ■ -CTAGAGGTCATGACCT TCCAGTACTGGAGATC-5• into the Xbal site at position -33 in pD33-ADH-CAT. pD33- ADH-CAT, without TREp, served as a control reporter (i.e., background) plasmid. A reference plasmid encoding beta-galactosidase driven by the actin 5C promoter also was transfected (0.5 μg/dish) along with pGEM DNA (4.5 μg/dish) (Promega, Madison, Wisconsin) to make up the final DNA concentration to 10 μg/dish. The reference plasmid was made by inserting a BamHI-site bounded, beta-galactosidase- encoding segment into the unique BamHI site of A5C. The purpose of the reference plasmid was to normalize results for transfection efficiency. Twenty-four hours post-transfection, various retinoids were added to the cultures. The retinoids were dissolved in dimethyl-sulfoxide and/or ethanol and the resulting solution was added to 0.1 % v/v of culture medium. Initial concentration of the retinoids in the culture media was 10 "6 M, except for the experiments underlying the data displayed in Figure 4, for which varying concentrations of retinoic acid were used. In control runs, ethanol, at 0.1 % v/v in the medium, was used in place of a solution of retinoid. Cultures were maintained in the dark for 36 hr after addition of retinoid and then harvested. All other parts of the experiments, involving retinoids, were carried out in subdued light. Cell lysates were centrifuged. Supernatants were assayed for beta-galactosidase, following Herbo el et al., Cell 39, 653-662 (-3^84), and units/ml of beta- galactosidase activity was calculated. CAT assays (normalized to beta-galactosidase activity) of supernatants were incubated for 75 unit-hours ("units" referring to units of beta-galactosidase activity) , as described by Gorman et al., Mol. Cell. Biol. 2, 1044 (1982) , usually 150 units for 30 minutes. No hRXR-alpha dependent activation of CAT expression was noted in any experiment in which control reporter was used in place of ADH-TREp-CAT. Similarly, essentially no activation was observed for runs where control plasmid, A5C-hRXR rev , was used in place of A5C-hRXR. The induction of CAT activity in retinoid-treated cells was compared with induction in untreated (i.e., only ethanol-treated) cells. Induction was measured in the presence of retinoic acid (RA) , retinal (RAL) , retinol acetate (RAC) , retinol (ROH) , and retinol palmitate (RP) . The production of chloramphenicol acetyltransferase (CAT) from the reporter vector (ADH-TREp-CAT) was measured in Drosophila melanogaster Schneider line 2 cells, co-trans¬ formed with the hRXR-alpha expression vector A5C-RXR- alpha, and exposed to a medium to which retinoic acid (RA) , retinal (RAL) , retinol acetate (RAC) , retinol (ROH) , or retinol palmitate (RP) has been added to a concentration of 10 "6 M. The relative induction observed was RA > RAL > RAC > ROH > RH. In Figure 4 are displayed the results, also expressed in terms of "fold-induction" of CAT activity, as described in the previous paragraph, with retinoic acid at a number of different concentrations, to show the "dose response" of hRXR-alpha (in trans-activation at TREp in insect cells) to retinoid acid in the medium of the cells. Example IV This example, describing experiments similar to those described in Example III, shows that hRAR-alpha and hRXR- alpha differ significantly in their properties, specifically with respect to trans-activation of transcription from promoters. The mammalian receptor-expression vector RS-hRAR- alpha, from which hRAR-alpha is produced under control of the 5'-LTR promoter of the rous sarcoma virus proviral DNA, is described in Giguere et al., Nature 330, 624 (1987) ; commonly asigned United States Patent Application Serial No. 276,536, filed November 30, 1988; and European Patent Application Publication No. 0 325 849, all incorporated herein by reference. The receptor-expression vector RS-hRXR-alpha is constructed similarly to RS-hRAR-alpha, by inserting the EcoRI-site-bounded, hRXR-alpha-encoding segment of lambda- XR3-1 into plasmid pRS (Giguere et al., Cell 46, 645 (1986)) . Control plasmid pRSns is pRS with a non-sense-coding sequence inserted in place of receptor-coding sequence. Reporter plasmid delta-MTV-TREp-CAT, also known as TREplMCAT, has also been described (Umesono et al., Nature 336, 262 (1988), Thompson and Evans, supra., see also Umesono and Evans, Cell 57, 1139 (1989). When a control reporter, designated delta-MTV-CAT, which is substantially delta-MTV-TREp-CAT with TREp removed, was used in place of delta-MTV-TREp-CAT, no CAT activity was found with either receptor with any of the retinoids or retinoid analogs. Reference plasmid, RS-beta-galactosidase, is also known and is substantially the same as RS-hRAR-alpha and RS-hRXR-alpha but has a beta-galactosidase-encoding segment in place of the receptor-encoding segment. Culture of CV-1 cells, co-transfections (with reporter plasmid, receptor-expression-plasmid or control plasmid, reference plasmid and inert plasmid DNA) and CAT assays were performed as described in Umesono et al., Nature 336, 262 (1988) . Co-transfections and CAT assays were carried out by methods similar to those described in Example III. Similar to the experiments in Example III, subdued light was used. When CV-1 cells co-transformed with reporter plasmid (delta-MTV-TREp-CAT) , reference plasmid, control plasmid (i.e., expressing no receptor), and receptor plasmid (RS-hRAR-alpha or RS-hRXR-alpha) , were exposed to retinoids RA, RAL, RAC, ROH, RP, (which are naturally occurring vitamin A metabolites) , or retinoid-free ethanol, the results shown in Figure 5 were obtained. The Figure illustrates production of CAT from reporter plasmid in monkey kidney cells of the CV-1 line, which are co- transformed with hRXR-alpha-producing expression vector RS-hRXR-alpha or hRAR-alpha-producing expression vector RS-hRAR. Experiments are carried out in a medium to which RA, RAL, KAC, ROH, or RP has been added to a concentration of 10 *6 M. The bars over the "-" sign indicate the levels of CAT production when the cells are exposed to no retinoid (i.e., retinoid-free ethanol). The hatched bars indicate the level of CAT production when a control expression vector, from which no receptor is expressed, is employed in place of the receptor expression vector. The open bars indicate the level of CAT production when receptor-producing expression vector is employed. In each case, the retinoids were added as ethanolic solutions, with the volume of solution 0.1 % (v/v) in the medium. Retinoid-free ethanol was added to 0.1 % v/v. Results are plotted as percentages of the maximal response observed in the experiments, i.e., hRXR-alpha with RA. In Figure 6, the results are provided for experiments carried out as described in the previous paragraph but with, in place of RAL, RAC, ROH and RP, the synthetic retinoids 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-4- iodo-2-antrhracenyl)-benzoic acid ("Rl") , ethyl-P-[ (E)-2- (5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl) -1- propenyl]-benzoic acid ("R2 11 ) , ethyl-all trans-9-(4- methoxy-2 , 3 , 6-trimethyl) -3 , 7-dimethyl-2 , 4 , 6 , 8- nonatetranoate ("R3") , and ethyl-all trans-9-(4-methoxy- 2,3,6-trimethyl)-3,7-dimethyl-2,4,6,8-nonatetraenoic acid ("R4") initially at a concentration of 10 "6 M. The Figure illustrates production of CAT from the reporter plasmid (delta-MTV-TREp-CAT), CV-1 cells, which are co-transformed with hRXR-alpha-producing expression vector RS-hRXR-alpha or the constitutive hRAR-alpha-producing expression vector RS-hRAR. Experiments are carried out in a medium to which RA, Rl, R2, R3, or R4 has been added to a concentration of 10 "6 M. The bars over the "-" sign indicate the levels of CAT production when the cells are exposed to no retinoid. The hatched bars indicate the level of CAT production when a control expression vector, from which no receptor is expressed, is employed in place of the receptor expression vector. The open bars indicate the level of CAT production when receptor-producing expression vector is employed. In Figure 7, results are presented for experiments carried out as described in this Example using various concentrations of retinoic acid. The Figure illustrates production of CAT from the reporter plasmid (delta-MTV- TRE -CAT) , in CV-1 cells, which are co-transformed with the receptor-producing expression vector RS-RXR-alpha or RS- RAR-alpha. Experiments are carried out in a medium to which RA has been added to various concentrations. In the Figure, the results are in terms of fold-induction observed with cells exposed to RA, and control cells (exposed to only RA-free ethanol) . In Figure 8, results are presented for experiments carried out as described above, using various concentrations of retinoic acid with expression vectors encoding mRXR-alpha, mRXR-beta and mRXR-gamma. In Figure 9, results are presented for experiments carried out as described above, using various concentrations of 3, 4-didehydroretinoic acid (ddRA) with expression vectors encoding mRXR-alpha, mRXR-beta and mRXR-gamma. Example V To determine the distribution of hRXR-alpha gene expression, poly A + RNAs isolated from a variety of adult rat tissues were size fractionated, transferred to a nylon filter, and hybridized with hRXR-alpha cDNA. Thus, for each tissue of adult male rat that was analyzed, total RNA was prepared from the tissue (see Chomczynski and Sacchi, Anal. Biochem. 162, 156 (1987)) and poly A * selected by oligo(dT)-cellulose chromatography. Ten micrograms of poly A + RNA were separated by 1% agarose- formaldehyde gel electrophoresis, transferred to a Nytran filter (Schleicher and Schuell) (see McDonnell et al., Science 235, 1214 (1987)), and hybridized under stringent conditions with the hRXR-alpha-encoding, EcoRI insert of lambda-XR3-l. Hybridization was performed at 42°C in a buffer containing 50% formamide, 5X Denhardt's, 5X SSPE, 0.1% SDS, lOOmg/ml salmon sperm DNA, 200mg/ml yeast RNA, and [ 32 P]-labelled probe. The filter was then washed twice with 2X SSC, 0.1% SDS at 22°C and twice at 50°C. Autoradiography was for 24h at -70°C with an intensifying screen. RNA ladder size markers from Bethesda Research Laboratories (Gaithersburg, Maryland, USA) The distribution of RXR-alpha mRNA in the rat reveals a pattern of expression distinct from that of the retinoid acid receptors (Giguere et al., Nature 330, 624 (1987); Zelent et al., Nature 339, 714 (1989); Benbrook, Nature 333, 669 (1988)). The rat RXR-alpha message appears to be a single species of about 4.8 kbp (kilobase pairs) which is expressed in many tissues, but most abundantly in the liver, muscle, lung, and kidney and somewhat less abundantly in adrenal, heart, intestine, and spleen. Example VI Molecular cloning analyses of the thyroid hormone and retinoic acid receptor genes indicate that each of these receptors belongs to a discreet gene subfamily which encode several receptor isoforms. To determine if this was also true of RXR, a series of Southern blot analyses were carried out. High stringency hybridization of restriction endonuclease-digested human DNA with a labelled DNA fragment derived from lambda-XR3-l produced a similar number of bands in every digestion, consistent with a single genetic locus. When the hybridization conditions were relaxed, however, many additional bands were observed in the products of each enzyme digestion. Careful inspection of this hybridization pattern demonstrated that it is unrelated to a similar analysis described for hRAR-alpha (Giguere et al., Nature 330, 624 (1987) . These observations indicate the presence of at least one other locus in the human genome related to the hRXR-alpha gene. Further, a genomic DNA zooblot representing mammalian, avian, yeast, and Drosophila species was obtained. Thus far, the RXR gene family appears to be present in all species tested except yeast, which to date has not been shown to contain any members of the steroid receptor superfamily. For the analyses of human DNA, two human placenta genomic DNA Southern blots were prepared in parallel with identical DNA samples. The blots were hybridized at high or low stringency with a " 1200 bp [ 32 P]-labelled fragment of lambda-XR3-l which included the coding portions of the DNA and ligand binding domains (Sequence ID No. 1, nucleotides 459-1631) . For the zooblot, genomic DNA from human, monkey, rat, mouse, dog, cow, rabbit, chicken, S. cerevisiae and Drosophila melanogaster were hybridized at low stringency with a " 330 bp [ 32 P]-labelled fragment of lambda-XR3-l which included the DNA-binding domain (Sequence ID No. 1, nucleotides 459-776) . Differently sized bands (in comparison with Hindlll-digested lambda DNA for sizing) were found for the various species. The blots for all of the species (including both for D. melanogaster) , except yeast, mouse and rabbit appeared to have more than one band. For the analysis of human DNA, the placental DNA was restricted with BamHI, Bglll, EcoRI, Hindlll, PstI and PvuII, separated in a 0.8% agarose gel (10 μg per lane) and transferred to nitrocellulose (see McDonnell et al., supra) and hybridized as described below. For the zooblot, EcoRI-digested DNA from the several species (Clontech, Palo Alto, California, USA) , other than D. melanogaster, was used for Southern blot analysis. EcoRI- and Xhol-digested D. melanogaster DNA was included also. Blots were hybridized at 42"C in the low stringency buffer described in Example I or at high stringency in the same buffer modified by addition of formamide to 50 %. Low stringency blots were washed twice at room temperature and twice at 50°C in 2X SSC, 0.1% SDS. The high stringency blot was washed twice at room temperature in 2X SSC, 0.1% SDS and twice at 65"C in 0.5X SSC, 0.1% SDS. Example VII Northern analysis were carried out on the mouse RXR isoforms alpha, beta and gamma, to determine the tissue distribution of these receptors in adult tissues and in developing embryos. Thus, mRNA (lOμg) was isolated from various adult rat tissues of from day 10.5-day 18.5 p.c. whole mouse embryos. These samples were subjected to Northern analysis using 32 P-labeled cDNA probes derived from regions specific to mRXRα, mRXR?, or mRXRγ. In the adult, the various RXR isoforms are seen to be expressed in both a specific and overlapping distribution pattern. In the embryo, the various isoforms are highly expressed in what appears to be a specific temporal pattern. The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. Deposit On January 31, 1990, a sample of replicatable phagescript SK double-stranded DNA (Stratagene, La Jolla, California, USA) , with the 1860 base-pair, EcoRI-site- bounded DNA, the sequence of which is illustrated in Figure 1, inserted at the unique EcoRI site, was deposited under the terms of the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purposes of Patent Procedure at the American Type Culture Collection, Rockville, Maryland, USA ("ATCC") . The accession number assigned to this deposit is ATCC 40741. The deposited DNA is designated pSK(hRXR-alpha) . Phagescript SK double-stranded DNA is a modified M13mpl8 bacteriophage DNA (double-stranded) . Derivatives, such as pSK(hRXR-alpha) , of phagescript SK double-stranded DNA can be cloned in the same way as M13mpl8 and its derivatives. Samples of pSK(hRXR-alpha) will be publicly available from the ATCC without restriction, except as provided in 37 CFR 1.801 et seq. , at the latest on the date an United States Patent first issues on this application or a continuing application thereof. Otherwise, in accordance with the Budapest Treaty and the regulations promulgated thereunder, samples will be available from the ATCC to all persons legally entitled to receive them under the law and regulations of any country or international organization in which an application, claiming priority of this application, is filed or in which a patent based on any such application is granted. SUMMARY OF SEQUENCES Sequence ID No. 1 is the coding sequence of an EcoRI- site-bounded DNA segment which encodes the novel receptor disclosed herein, referred to as human RXR-alpha [hRXRα] Sequence ID No. 2 is the amino acid sequence of the novel receptor referred to herein as hRXRα. Sequence ID No. 3 is the nucleotide (and amino acid) sequence of the novel receptor disclosed herein, referred to as mouse RXR-alpha [mRXRα] . Sequence ID No. 4 is the amino acid sequence of the novel receptor referred to herein as mRXRα. Sequence ID No. 5 is the nucleotide (and amino acid) sequence of the novel receptor disclosed herein, referred to as mouse RXR-gam a [mRXRγ] . Sequence ID No. 6 is the amino acid sequenase of the novel receptor referred to herein as mRXRγ. Sequence ID No. 7 is the nucleotide sequence of the receptor disclosed by Hamada, et al in PNAS B6_: 8298-8293 (1989) . This receptor is similar to the receptor referred to herein as mRXRø. SEQ ID NO:1 : GAATTCCGGC GCCGGGGGCC GCCCGCCCGC CGCCCGCTGC CTGCGCCGCC GGCCGGGCAT 60 GAGTTΛGTCG CAGAC ATG GAC ACC AAA CAT TTC CTG CCG CTC GAT TTC TCC 111 Met Asp Thr Lys His- Phe Leu Pro Leu Asp Phe Ser 1 5 10 ACC CAG GTG AAC TCC TCC CTC ACC TCC CCG ACG GGG CGA GGC TCC ATG 159 Thr Gin Val Asn Ser Ser Leu Thr Ser Pro Thr Gly Arg Gly Ser Met 15 20 25 GCT GCC CCC TCG CTG CAC CCG TCC CTG GGG CCT GGC ATC GGC TCC CCG 207 Ala Ala Pro Ser Leu His Pro Ser Leu Gly Pro Gly lie Gly Ser Pro 30 35 40 GGA CAG CTG CAT TCT CCC ATC AGC ACC CTG AGC TCC CCC ATC AAC GGC 255 Gly Gin Leu His Ser Pro lie Ser Thr Leu Ser Ser Pro He Asn Gly 45 50 55 60 ATG GGC CCG CCT TTC TCG GTC ATC AGC TCC CCC ATG GGC CCC CAC TCC 303 Het Gly Pro Pro Phe Ser Val He Ser Ser Pro Met Gly Pro His Ser 65 70 75 ATG TCG GTG CCC ACC ACA CCC ACC CTG GGC TTC AGC ACT GGC AGC CCC 351 Het Ser Val Pro Thr Thr Pro Thr Leu Gly Phe Ser Thr Gly Ser Pro 80 85 90 CAG CTC AGC TCA CCT ATG AAC CCC GTC AGC AGC AGC GAG GAC ATC AAG 399 Gin Leu Ser Ser Pro Het Asn Pro Val Ser Ser Ser Glu Asp He Lys 95 100 105 CCC CCC CTG GGC CTC AAT GGC GTC CTC AΛE GTC CCC GCC CAC CCC TCA 447 Pro Pro Leu Gly Leu Asn Gly Val Leu Lys Val Pro Ala His Pro Ser 110 115 120 GGA AAC ATG GCT TCC TTC ACC AAG CAC ATC TGC GCC ATC TGC GGG GAC 495 Gly Asn Het Ala Ser Phe Thr Lys His He Cys Ala He Cys Gly Asp 125 130 135 140 CGC TCC TCA GGC AAG CAC TAT GGA GTG TAC AGC TGC GAG GGG TGC AAG 543 Arg Ser Ser Gly Lys His Tyr Gly Val Tyr Sfer Cys Glu Gly Cys Lys 145 150 155 GGC TTC TTC AAG CGG ACG GTG CGC AAG GAC CTG ACC TAC ACC TGC CGC 591 Gly Phe Phe Lys Arg Thr Val Arg Lys Asp * Leu Thr Tyr Thr Cys Arg 160 165 170 GAC AAC AAG GAC TGC CTG ATT GAC AAG CGG CAG CGG AAC CGG TGC CAG 639 Asp Asn Lys Asp Cys Leu He Asp Lys Arg Gin Arg Asn Arg Cys Gin 175 180 185 TAC TGC CGC TAC CAG AAG TGC CTG GCC ATG GGC ATG AAG CGG GAA GCC 687 Tyr Cys Arg Tyr Gin Lys Cys Leu Ala Het Gly Het Lys Arg Glu Ala 190 195 200 GTG CAG GAG GAG CGG CAG CGT GGC AAG GAC CGG AAC GAG AAT GAG GTG 735 Val Gin Glu Glu Arg Gin Arg Gly Lys Asp Arg Asn Glu Asn Glu Val 205 210 215 220 GAG TCG ACC AGC AGC GCC AAC GAG GAC ATG CCG GTG GAG AGG ATC CTG 783 Glu Ser Thr Ser Ser Ala Asn Glu Asp Met Pro Val Glu Arg He Leu 225 230 235 GAG GCT GAG CTG GCC GTG GAG CCC AAG ACC GAG ACC TAC GTG GAG GCA 831 Glu Ala Glu Leu Ala Val Glu Pro Lys Thr Glu Thr Tyr Val Glu Ala 240 245 250 AAC ATG GGG CTG AAC CCC AGC TCG CCG AAC GAC CCT GTC ACC AAC ATT 879 Asn Het Gly Leu Asn Pro Ser Ser Pro Asn Asp Pro Val Thr Asn He 255 260 265 TGC CAA GCA GCC GAC AAA CAG CTT TTC ACC CTG GTG GAG TGG GCC AAG 927 Cys Gin Ala Ala Asp Lys Gin Leu Phe Thr Leu Val Glu Trp Ala Lys 270 275 280 CGG ATC CCA CAC TTC TCA GAG CTG CCC CTG GAC GAC CAG GTC ATC CTG 975 Arg He Pro His Phe Ser Glu Leu Pro Leu Asp Asp Gin Val He Leu 285 290 295 300 CTG CGG GCA GGC TGG AAT GAG CTG CTC ATC GCC TCC TTC TCC CAC CGC 1023 Leu Arg Ala Gly Trp Asn Glu Leu Leu He Ala Ser Phe Ser His Arg 305 310 315 TCC ATC GCC GTG AAG GAC GGG ATC CTC CTG GCC ACC GGG CTG CAC GTC 1071 Ser He Ala Val Lys Asp Gly He Leu Leu Ala Thr Gly Leu His Val 320 325 330 CAC CGG AAC AGC GCC CAC AGC GCA GGG GTG GGC GCC ATC TTT GAC AGG 1119 His Arg Asn Ser Ala His Ser Ala Gly Val Gly Ala He Phe Asp Arg 335 340 345 GTG CTG ACG GAG CTT GTG TCC AAG ATG CGG GAC ATG CAG ATG GAC AAG 1167 Val Leu Thr Glu Leu Val Ser Lys Het Arg Asp Het Gin Het Asp Lys 350 355 360 ACG GAG CTG GGC TGC CTG CGC GCC ATC GTC CTC TTT AAC CCT GAC TCC 1215 Thr Glu Leu Gly Cys Leu Arg Ala He Val Leu Phe Asn Pro Asp Ser 365 370 375 380 AAG GGG CTC TCG AAC CCG GCC GAG GTG GAG GCG CTG AGG GAG AAG GTC 1263 Lys Gly Leu Ser Asn Pro Ala Glu Val Glu Ala Leu Arg Glu Lys Val 385 390 395 TAT GCG TCC TTG GAG GCC TAC TGC AAG CAC AAG TAC CCA GAG CAG CCG 1311 Tyr Ala Ser Leu Glu Ala Tyr Cys Lys His Lys Tyr Pro Glu Gin Pro 400 405 410 GGA AGG TTC GCT AAG CTC TTG CTC CGC CTG CCG GCT CTG CGC TCC ATC 1359 Gly Arg Phe Ala Lys Leu Leu Leu Arg Leu Pro Ala Leu Arg Ser He 415 420 425 GGG CTC AAA TGC CTG GAA CAT CTC TTC TTC TTC AAG CTC ATC GGG GAC 1407 Gly Leu Lys Cys Leu Glu His Leu Phe Phe Phe Lys Leu He Gly Asp 430 435 440 ACA CCC ATT GAC ACC TTC CTT ATG GAG ATG CTG GAG GCG CCG CAC CAA 1455 Thr Pro He Asp Thr Phe Leu Het Glu Het Leu Glu Ala Pro His Gin 445 450 455 460 ATG ACT TAGGCCTGCG GGCCCATCCT TTGTGCCCAC CCGTTCTGGC CACCCTGCCT 1511 Het Thr GGACGCCAGC TGTTCTTCTC AGCCTGAGCC CTGTCCCTGC CCTTCTCTGC CTGGCCTGTT 1571 TGGACTTTGG GGCACAGCCT GTCACTGCTC TGCCTAAGAG ATGTGTTGTC ACCCTCCTTA 1631 TTTCTGTTAC TACTTGTCTG TGGCCCAGGG CAGTGGCTTT CCTGAGCAGC AGCCTTCGTG 1691 GCAAGAACTA GCGTGAGCCC AGCCAGGCGC CTCCCCACCG GGCTCTCAGG ACGCCCTGCC 1751 ACACCCACGG GGCTTGGGCG ACTACAGGGT CTTCGGCCCC AGCCCTGGAG CTGCAGGAGT 1811 TGGGAACGGG GCTTTTGTTT CCGTTGCTGT TTATCGATGC TGGTTTTCAG AATTC 1866 SEQ ID N0:2: Het Asp Thr Lys His Phe Leu Pro Leu Asp Phe Ser Thr Gin Val Asn 1 5 10 15 Ser Ser Leu Thr Ser Pro Thr Gly Arg Gly Ser Het Ala Ala Pro Ser 20 25 30 Leu His Pro Ser Leu Gly Pro Gly He Gly Ser Pro Gly Gin Leu His 35 40 45 Ser Pro He Ser Thr Leu Ser Ser Pro He Asn Gly Met Gly Pro Pro 50 55 60 Phe Ser Val He Ser Ser Pro Met Gly Pro His Ser Met Ser Val Pro 65 70 75 80 Thr Thr Pro Thr Leu Gly Phe Ser Thr Gly Ser Pro Gin Leu Ser Ser 85 90 95 Pro Het Asn Pro Val Ser Ser Ser Glu Asp He Lys Pro Pro Leu Gly 100 105 110 Leu Asn Gly Val Leu Lys Val Pro Ala His Pro Ser Gly Asn Met Ala 115 120 125 Ser Phe Thr Lys His He Cys Ala He Cys Gly Asp Arg Ser Ser Gly 130 135 140 Lys His Tyr Gly Val Tyr Ser Cys Glu Gly Cys Lys Gly Phe Phe Lys 145 150 155 160 Arg Thr Val Arg Lys Asp Leu Thr Tyr Thr Cys Arg Asp Asn Lys Asp 165 170 175 Cys Leu He Asp Lys Arg Gin Arg Asn Arg Cys Gin Tyr Cys Arg Tyr 180 185 190 Gin Lys Cys Leu Ala Het Gly Het Lys Arg Glu Ala Val Gin Glu Glu 195 200 205 Arg Gin Arg Gly Lys Asp Arg Asn Glu Asn Glu Val Glu Ser Thr Ser 210 215 220 Ser Ala Asn Glu Asp Het Pro Val Glu Arg He Leu Glu Ala Glu Leu 225 230 235 240 Ala Val Glu Pro Lys Thr Glu Thr Tyr Val Glu Ala Asn Het Gly Leu 245 250 255 Asn Pro Ser Ser Pro Asn Asp Pro Val Thr Asn He Cys Gin Ala Ala 260 265 270 Asp Lys Gin Leu Phe Thr Leu Val Glu Trp Ala Lys Arg He Pro His 275 280 285 Phe Ser Glu Leu Pro Leu Asp Asp Gin Val He Leu Leu Arg Ala Gly 290 295 300 Trp Asn Glu Leu Leu He Ala Ser Phe Ser His Arg Ser He Ala Val 305 310 315 320 Lys Asp Gly He Leu Leu Ala Thr Gly Leu His Val His Arg Asn Ser 325 330 335 Ala His Ser Ala Gly Val Gly Ala He Phe Asp Arg Val Leu Thr Glu 340 345 350 Leu Val Ser Lys Met Arg Asp Het Gin Het Asp Lys Thr Glu Leu Gly 355 360 365 Cys Leu Arg Ala He Val Leu Phe Asn Pro Asp Ser Lys Gly Leu Ser 370 375 380 Asn Pro Ala Glu Val Glu Ala Leu Arg Glu Lys Val Tyr Ala Ser Leu 385 390 395 400 Glu Ala Tyr Cys Lys His Lys Tyr Pro Glu Gin Pro Gly Arg Phe Ala 405 410 415 Lys Leu Leu Leu Arg Leu Pro Ala Leu Arg Ser He Gly Leu Lys Cys 420 425 430 Leu Glu His Leu Phe Phe Phe Lys Leu He Gly Asp Thr Pro He Asp 435 440 445 Thr Phe Leu Het Glu Hεt Leu Glu Ala Pro His Gin Met Thr 450 455 460 SEQ ID N0:3: GAATTCGCGG CCGCGGCGAC TTTTGCAACA ACTCGCCGCG CCGCGGCCTC CGCGCGCCGC 60 CGCCGCCGCT GCCGCCGCCG GCTCCCCGCC GCCCGGGCCC CGGGCGGGCC GCGCCGGGGG 120 CCGCCGCGCT GCCGCCCTGC TGCTCCGCCG CCGGCTGGGC ATGAGTTAGT CGCAGAC 177 ATG GAC ACC AAA CAT TTC CTG CCG CTC GAC TTC TCT ACC CAG GTG AAC 225 Met Asp Thr Lys His Phe Leu Pro Leu Asp Phe Ser Thr Gin Val Asn 1 5 10 15 TCT TCG TCC CTC AAC TCT CCA ACG GGT CGA GGC TCC ATG GCT GTC CCC 273 Ser Ser Ser Leu Asn Ser Pro Thr Gly Arg Gly Ser Met Ala Val Pro 20 25 30 TCG CTG CAC CCC TCC TTG GGT CCG GGA ATC GGC TCT CCA CTG GGC TCG 321 Ser Leu His Pro Ser Leu Gly Pro Gly He Gly Ser Pro Leu Gly Ser 35 40 45 CCT GGG CAG CTG CAC TCT CCT ATC AGC ACC CTG AGC TCC CCC ATC AAT 369 Pro Gly Gin Leu His Ser Pro He Ser Thr Leu Ser Ser Pro He Asn 50 55 60 GGC ATG GGT CCG CCC TTC TCT GTC ATC AGC TCC CCC ATG GGC CCG CAC 417 Gly Met Gly Pro Pro Phe Ser Val He Ser Ser Pro Het Gly Pro His 65 70 75 80 TCC ATG TCG GTA CCC ACC ACA CCC ACA TTG GGC TTC GGG ACT GGT AGC 465 Ser Het Ser Val Pro Thr Thr Pro Thr Leu Gly Phe Gly Thr Gly Ser 85 90 95 CCC CAG CTC AAT TCA CCC ATG AAC CCT GTG AGC AGC ACT GAG GAT ATC 513 Pro Gin Leu Asn Ser Pro Het Asn Pro Val Ser Ser Thr Glu 1 Asp He 100 105 110 AAG CCG CCA CTA GGC CTC AAT GGC GTC CTC AAG GTT CCT GCC CAT CCC 561 Lys Pro Pro Leu Gly Leu Asn Gly Val Leu Lys Val Pro Ala His Pro 115 120 125 TCA GGA AAT ATG GCC TCC TTC ACC AAG CAC ATC TGT GCT ATC TGT GGG 609 Ser Gly Asn Het Ala Ser Phe Thr Lys His He Cys Ala He Cys Gly 130 135 140 GAC CGC TCC TCA GGC AAA CAC TAT GGG GTA TAC AGT TGT GAG GGC TGC 657 Asp Arg Ser Ser Gly Lys His Tyr Gly Val Tyr Ser Cys Glut Gly Cys 145 150 155 160 AAG GGC TTC TTC AAG AGG ACA GTA CGC AAA GAC CTG ACC TAC ACC TGC 705 Lys Gly Phe Phe Lys Arg Thr Val Arg Lys Asp Leu Thr Tyr Thr Cys 165 170 175 CGA GAC AAC AAG GAC TGC CTG ATC GAC AAG AGA CAG CGG AAC CGG TGT 753 Arg Asp Asn Lys Asp Cys Leu He Asp Lys Arg Gin Arg Asn Arg Cys 180 185 190 CAG TAC TGC CGC TAC CAG AAG TGC CTG GCC ATG GGC ATG AAG CGG GAA 801 Gin Tyr Cys Arg Tyr Gin Lys Cys Leu Ala Het Gly Het Lys Arg Glu 195 200 205 GCT GTG CAG GAG GAG CGG CAG CGG GGC AAG GAC CGG AAT GAG AAC GAG 849 Ala Val Gin Glu Glu Arg Gin Arg Gly Lys Asp Arg Asn Glu Asn Glu 210 215 220 GTG GAG TCC ACC AGC AGT GCC AAC GAG GAC ATG CCT GTA GAG AAG ATT 897 Val Glu Ser Thr Ser Ser Ala Asn Glu Asp Het Pro Val Glu Lys He 225 230 235 240 CTG GAA GCC GAG CTT GCT GTC GAG CCC AAG ACT GAG ACA TAC GTG GAG 945 Leu Glu Ala Glu Leu Ala Val Glu Pro Lys Thr Glu Thr Tyr Val Glu 245 250. 255 GCA AAC ATG GGG CTG AAC CCC AGC TCA CCA AAT GAC CCT GTT ACC AAC 993 Ala Asn Het Gly Leu Asn Pro Ser Ser Pro Asn Asp Pro Val Thr Asn 260 265 270 ATC TGT CAA GCA GCA GAC AAG CAG CTC TTC ACT CTT GTG GAG TGG GCC 1041 He Cys Gin Ala Ala Asp Lys Gin Leu Phe Thr Leu Val Glu Trp Ala 275 280 285 AAG AGG ATC CCA CAC TTT TCT GAG CTG CCC CTA GAC GAC CAG GTC ATC 1089 Lys Arg He Pro His Phe Ser Glu Leu Pro Leu Asp Asp Gin Val He 290 295 300 CTG CTA CGG GCA GGC TGG AAC GAG CTG CTG ATC GCC TCC TTC TCC CAC 1137 Leu Leu Arg Ala Gly Trp Asn Glu Leu Leu He Ala Ser Phe Ser His 305 310 315 320 CGC TCC ATA GCT GTG AAA GAT GGG ATT CTC CTG GCC ACC GGG CTG CAC 1185 Arg Ser He Ala Val Lys Asp Gly He Leu Leu Ala Thr Gly Leu His 325 330 335 GTA CAC CGG AAC AGC GCT CAC AGT GCT GGG GTG GGC GCC ATC TTT GAC 1233 Val His Arg Asn Ser Ala His Ser Ala Gly Val Gly Ala He Phe Asp 340 345 350 AGG GTG CTA ACA GAG CTG GTG TCT AAG ATG CGT GAC ATG CAG ATG GAC 1281 Arg Val Leu Thr Glu Leu Val Ser Lys Het Arg Asp Het Gin Het Asp 355 360 365 AAG ACG GAG CTG GGC TGC CTG CGA GCC ATT GTC CTG TTC AAC CCT GAC 1329 Lys Thr Glu Leu Gly Cys Leu Arg Ala He Val Leu Phe Asn Pro Asp 370 375 380 TCT AAG GGG CTC TCA AAC CCT GCT GAG GTG GAG GCG TTG AGG GAG AAG 1377 Ser Lys Gly Leu Ser Asn Pro Ala Glu Val Glu Ala Leu Arg Glu Lys 385 390 395 40Q GTG TAT GCG TCA CTA GAA GCG TAC TGC AAA CAC AAG TAC CCT GAG CAG 1425 Val Tyr Ala Ser Leu Glu Ala Tyr Cys Lys His Lys Tyr Pro Glu Gin 405 410 415 CCG GGC AGG TTT GCC AAG CTG CTG CTC CGC CTG CCT GCA CTG CGT TCC 1473 Pro Gly Arg Phe Ala Lys Leu Leu Leu Arg Leu Pro Ala Leu Arg Ser 420 425 430 ATC GGG CTC AAG TGC CTG GAG CAC CTG TTC TTC TTC AAG CTC ATC GGG 1521 He Gly Leu Lys Cys Leu Glu His Leu Phe Phe Phe Lys Leu He Gly 435 440 445 GAC ACG CCC ATC GAC ACC TTC CTC ATG GAG ATG CTG GAG GCA CCA CAT 1569 Asp Thr Pro He Asp Thr Phe Leu Het Glu Het Leu Glu Ala Pro His 450 455 460 CAA GCC ACC TAGGCCCCCG CCGCCGTGTG CCGGTCCCGT GCCCTGCCTG 1618 Gin Ala Thr 465 GACACAGCTG CTCAGCTCCA GCCCTGCCCC TGCCCTTTCT GATGGCCCGT GTGGATCTTT 1678 GGGGTGCAGT GTCCTTATGG GCCCAAAAGA TGCATCACCA TCCTCGCCAT CTTTACTCAT 1738 GCTTGCCTTT GGCCCAGGGC ATAGCAGAGC TGGTGTGACA CCTGGCCAGC TCCTGCCCTA 1798 CATCAGGCTC TAAGGCTATG CTGCTGTCAC CCCGAGGGTC GTGGGGTTCG TCATGGGGCC 1858 TTCAGCACCT GGAGCTGCAA GAGCTGGGAA AAGGGCTTGT TCTGGTTGCT GGTTGCTGGT 1918 CGCTGGTTCT CGACATCCCA CATGGCACCT CTGTTTGGAG TGCCCCATCT TGGCCTGTTC 1978 AGAGTCCTGG TACCCAGTTA GGGTGGGAAT CCACCTGGGA TCAAGAAGGA GCAGGTGGGG 2038 CAGGCCGTAT CCTCCTGGGT CATAGCTAAC CTATAAAGGC GCCGCGAATT CCTCGAG 2095 SEQ ID NO:4: Het Asp Thr Lys His Phe Leu Pro Leu Asp Phe Ser Thr Gin Val Asn 1 5 10 15 Ser Ser Ser Leu Asn Ser Pro Thr Gly Arg Gly Ser Het Ala Val Pro 20 25 30 Ser Leu His Pro Ser Leu Gly Pro Gly He Gly Ser Pro Leu Gly Ser 35 40 45 Pro Gly Gin Leu His Ser Pro He Ser Thr Leu Ser Ser Pro He Asn 50 55 60 Gly Het Gly Pro Pro Phe Ser Val He Ser Ser Pro Het Gly Pro His 65 70 75 80 Ser Het Ser Val Pro Thr Thr Pro Thr Leu Gly Phe Gly Thr Gly Ser 85 90 95 Pro Gin Leu Asn Ser Pro Het Asn Pro Val Ser Ser Thr Glu Asp He 100 105 110 Lys Pro Pro Leu Gly Leu Asn Gly Val Leu Lys Val Pro Ala His Pro 115 120 125 Ser Gly Asn Het Ala Ser Phe Thr Lys His He Cys Ala He Cys Gly 130 135 140 Asp Arg Ser Ser Gly Lys His Tyr Gly Val Tyr Ser Cys Glu Gly Cys 145 150 155 160 Lys Gly Phe Phe Lys Arg Thr Val Arg Lys Asp Leu Thr Tyr Thr Cys 165 170 175 Arg Asp Asn Lys Asp Cys Leu He Asp Lys Arg Gin Arg Asn Arg Cys 180 185 190 Gin Tyr Cys Arg Tyr Gin Lys Cys Leu Ala Het Gly Het Lys Arg Glu 195 200 205 Ala Val Gin Glu Glu Arg Gin Arg Gly Lys Asp Arg Asn Glu Asn Glu 210 215 220 Val Glu Ser Thr Ser Ser Ala Asn Glu Asp Het Pro Val Glu Lys He 225 230 235 240 Leu Glu Ala Glu Leu Ala Val Glu Pro Lys Thr Glu Thr Tyr Val Glu 245 250 255 Ala Asn Het Gly Leu Asn Pro Ser Ser Pro Asn Asp Pro Val Thr Asn 260 265 270 He Cys Gin Ala Ala Asp Lys Gin Leu Phe Thr Leu Val Glu Trp Ala 275 280 285 Lys Arg He Pro His Phe Ser Glu Leu Pro Leu Asp Asp Gin Val He 290 295 300 Leu Leu Arg Ala Gly Trp Asn Glu Leu Leu He Ala Ser Phe Ser His 305 310 315 320 Arg Ser He Ala Val Lys Asp Gly He Leu Leu Ala Thr Gly Leu His 325 330 335 Val His Arg Asn Ser Ala His Ser Ala Gly Val Gly Ala He Phe Asp 340 345 350 Arg Val Leu Thr Glu Leu Val Ser Lys Het Arg Asp Het Gin Met Asp 355 360 365 Lys Thr Glu Leu Gly Cys Leu Arg Ala He Val Leu Phe Asn Pro Asp 370 375 380 Ser Lys Gly Leu Ser Asn Pro Ala Glu Val Glu Ala Leu Arg Glu Lys 385 390 395 400 Val Tyr Ala Ser Leu Glu Ala Tyr Cys Lys His Lys Tyr Pro Glu Gin 405 410 415 Pro Gly Arg Phe Ala Lys Leu Leu Leu Arg Leu Pro Ala Leu Arg Ser 420 425 430 He Gly Leu Lys Cys Leu Glu His Leu Phe Phe Phe Lys Leu He Gly 435 440 445 Asp Thr Pro He Asp Thr Phe Leu Het Glu Het Leu Glu Ala Pro His 450 455 460 Gin Ala Thr 465 SEQ ID NO:5: GAATTCGCGG CCGCGCTGTG CCTGGGAGCC GAGAGAGAGA GAGAGAGAGA GAGAGAGAGA 60 GAGAGAGAGA GAGAGGCTGT ACTCTTCAGA AGCGCACGAG AGGAATGAAC TGAGCAGCCA 120 AC ATG TAT GGA AAT TAT TCC CAC TTC ATG AAG TTT CCC ACC GGC TTT 167 Het Tyr Gly Asn Tyr Ser His Phe Het Lys Phe Pro Thr Gly Phe 1 5 ' 10 15 GGT GGC TCC CCT GGT CAC ACT GGC TCG ACG TCC ATG AGC CCT TCA GTA 215 Gly Gly Ser Pro Gly His Thr Gly Ser Thr Ser Het Ser Pro Ser Val 20 25 30 GCC TTG CCC ACG GGG AAG CCA ATG GAC AGC CAC CCC AGC TAC ACA GAC 263 Ala Leu Pro Thr Gly Lys Pro Het Asp Ser His Pro Ser Tyr Thr Asp 35 40 45 ACC CCA GTG AGT GCC CCT CGG ACG CTG AGT GCT GTG GGA ACC CCC CTC 311 Thr Pro Val Ser Ala Pro Arg Thr Leu Ser Ala Val Gly Thr Pro Leu 50 55 60 - AAT GCT CTT GGC TCT CCG TAT AGA GTC ATC ACT TCT GCC ATG GGT CCA 359 Asn Ala Leu Gly Ser Pro Tyr Arg Val He Thr Ser Ala Het Gly Pro 65 70 75 CCC TCA GGA GCA CTG GCA GCT CCT CCA GGA ATC AAC TTG GTG GCT CCA 407 Pro Ser Gly Ala Leu Ala Ala Pro Pro Gly He Asn Leu Val Ala Pro 80 85 90 95 CCC AGC TCC CAG CTA AAT GTG GTC AAC AGT GTC AGC AGC TCT GAG GAC 455 Pro Ser Ser Gin Leu Asn Val Val Asn Ser Val Ser Ser Ser Glu Asp 100 105 110 ATC AAG CCC TTA CCA GGT CTG CCT GGG ATT GGA AAT ATG AAC TAC CCA 503 He Lys Pro Leu Pro Gly Leu Pro Gly He Gly Asn Het Asn Tyr Pro 115 120 125 TCC ACC AGC CCT GGG TCT CTG GTG AAA CAC ATC TGT GCC ATC TGT GGG 551 Ser Thr Ser Pro Gly Ser Leu Val Lys His He Cys Ala He Cys Gly 130 135 140 GAC AGA TCC TCA GGG AAG CAC TAC GGT GTG TAC AGC TGT GAA GGT TGC 599 Asp Arg Ser Ser Gly Lys His Tyr Gly Val Tyr Ser Cys Glu Gly Cys 145 150 155 AAA GGC TTC TTC AAA AGG ACC ATC AGG AAA GAT CTC ATC TAC ACC TGT 647 Lys Gly Phe Phe Lys Arg Thr He Arg Lys Asp Leu He Tyr Thr Cys 160 165 170 175 CGG GAT AAC AAA GAT TGT CTC ATC GAC AAG CGC CAG CGC AAC CGC TGC 695 Arg Asp Asn Lys Asp Cys Leu He Asp Lys Arg Gin Arg Asn Arg Cys 180 185 190 CAG TAC TGT CGC TAC CAG AAG TGC CTG GTC ATG GGC ATG AAG CGG GAA 743 Gin Tyr Cys Arg Tyr Gin Lys Cys Leu Val Het Gly Het Lys Arg Glu 195 200 205 GCT GTG CAA GAA GAA AGG CAG AGG AGC CGA GAG CGA GCA GAG AGT GAG 791 Ala Val Gin Glu Glu Arg Gin Arg Ser Arg. Glu Arg Ala Glu Ser Glu 210 215 220 GCA GAA TGT GCC AGT AGT AGC CAC GAA GAC ATG CCC GTG GAG AGG ATT 839 Ala Glu Cys Ala Ser Ser Ser His Glu Asp Het Pro Val Glu Arg He 225 230 235 CTA GAA GCC GAA CTT GCT GTG GAA CCA AAG ACA GAA TCC TAC GGT GAC 887 Leu Glu Ala Glu Leu Ala Val Glu Pro Lys Thr Glu Ser Tyr Gly Asp 240 245 250 255 ATG AAC GTG GAG AAC TCA ACA AAT GAC CCT GTT ACC AAC ATA TGC CAT 935 Met Asn Val Glu Asn Ser Thr Asn Asp Pro Val Thr Asn He Cys His 260 265 270 GCT GCA GAT AAG CAA CTT TTC ACC CTC GTT GAG TGG GCC AAA CGC ATC 983 Ala Ala Asp Lys Gin Leu Phe Thr Leu Val Glu Trp Ala Lys Arg He 275 280 285 CCC CAC TTC TCA GAT CTC ACC TTG GAG GAC CAG GTC ATT CTA CTC CGG 1031 Pro His Phe Ser Asp Leu Thr Leu Glu Asp Gin Val He Leu Leu Arg 290 295 300 GCA GGG TGG AAT GAA CTG CTC ATT GCC TCC TTC TCC CAC CGC TCG GTT 1079 Ala Gly Trp Asn Glu Leu Leu He Ala Ser Phe Ser His Arg Ser Val 305 310 315 TCC GTC CAG GAT GGC ATC CTG CTG GCC ACG GGC CTC CAC GTG CAC AGG 1127 Ser Val Gin Asp Gly He Leu Leu Ala Thr Gly Leu His Val His Arg 320 325 330 335 AGC AGC GCT CAC AGC CGG GGA GTC GGC TCC ATC TTC GAC AGA GTC CTT 1175 Ser Ser Ala His Ser Arg Gly Val Gly Ser He Phe Asp Arg Val Leu 340 345 350 ACA GAG TTG GTG TCC AAG ATG AAA GAC ATG CAG ATG GAT AAG TCA GAG 1223 Thr Glu Leu Val Ser Lys Het Lys Asp Het Gin Het Asp Lys Ser Glu 355 360 365 CTG GGG TGC CTA CGG GCC ATC GTG CTG TTT AAC CCA GAT GCC AAG GGT 1271 Leu Gly Cys Leu Arg Ala He Val Leu Phe Asn Pro Asp Ala Lys Gly 370 375 380 TTA TCC AAC CCC TCT GAG GTG GAG ACT CTT CGA GAG AAG GTT TAT GCC 1319 Leu Ser Asn Pro Ser Glu Val Glu Thr Leu Arg Glu Lys Val Tyr Ala 385 390 395 ACC CTG GAG GCC TAT ACC AAG CAG AAG TAT CCG GAA CAG CCA GGC AGG 1367 Thr Leu Glu Ala Tyr Thr Lys Gin Lys Tyr Pro Glu Gin Pro Gly Arg 400 405 410 415 TTT GCC AAG CTT CTG CTG CGT CTC CCT GCT CTG CGC TCC ATC GGC TTG 1415 Phe Ala Lys Leu Leu Leu Arg Leu Pro Ala Leu Arg Ser He Gly Leu 420 425 430 AAA TGC CTG GAA CAC CTC TTC TTC TTC AAG CTC ATT GGA GAC ACT CCC 1463 Lys Cys Leu Glu His Leu Phe Phe Phe Lys Leu He Gly Asp Thr Pro 435 440 445 ATC GAC AGC TTC CTC ATG GAG ATG TTG GAG ACC CCA CTG CAG ATC ACC 1511 He Asp Ser Phe Leu Het Glu Het Leu Glu Thr Pro Leu Gin He Thr 450 455 460 TGAACCTCCT CAGCTGCAGC TTCCCCACCC AGGGTGACCC TTGGGCGGGT GTGTGTGTGT 1571 GGCCCTACCC TGCACACTCT CCCCCATCTT CCACTCTGGC CTCCCTTCCT GTCCCCAAAA 1631 TGTGATGCTT GTAATAAGCG GCCGCGAATT C 1662 SEQ ID 110:6: Het Tyr Gly Asn Tyr Ser His Phe Het Lys Phe Pro Thr Gly Phe Gly 1 5 \0> 15 Gly Ser Pro Gly His Thr Gly Ser Thr Ser Het Ser Pro Ser Val Ala 20 25 30 Leu Pro Thr Gly Lys Pro Het Asp Ser His Pro Ser Tyr Thr Asp Thr 35 40 45 Pro Val Ser Ala Pro Arg Thr Leu Ser Ala Val Gly Thr Pro Leu Asn 50 55 60 Ala Leu Gly Ser Pro Tyr Arg Val He Thr Ser Ala Met Gly Pro Pro 65 70 75 80 Ser Gly Ala Leu Ala Ala Pro Pro Gly He Asn Leu Val Ala Pro Pro 85 90 95 Ser Ser Gin Leu Asn Val Val Asn Ser Val Ser Ser Ser Glu Asp He 100 105 110 Lys Pro Leu Pro Gly Leu Pro Gly He Gly Asn Het Asn Tyr Pro Ser 115 120 125 Thr Ser Pro Gly Ser Leu Val Lys His lie Cys Ala He Cys Gly Asp liu !._>:_> ι<ιu Arg Ser Ser Gly Lys His Tyr Gly Val Tyr Ser Cys Glu Gly Cys Lys 145 150 155 160 Gly Phe Phe Lys Arg Thr He Arg Lys Asp Leu He Tyr Thr Cys Arg 165 170 175 Asp Asn Lys Asp Cys Leu He Asp Lys Arg Gin Arg Asn Arg Cys Gin 180 185 190 Tyr Cys Arg Tyr Gin Lys Cys Leu Val Het Gly Met Lys Arg Glu Ala 195 200 205 Val Gin Glu Glu Arg Gin Arg Ser Arg Glu Arg Ala Glu Ser Glu Ala 210 215 220 Glu Cys Ala Ser Ser Ser His Glu Asp Met Pro Val Glu Arg He Leu 225 230 235 240 Glu Ala Glu Leu Ala Val Glu Pro Lys Thr Glu Ser Tyr Gly Asp Het 245 250 255 Asn Val Glu Asn Ser Thr Asn Asp Pro Val Thr Asn He Cys His Ala 260 265 270 Ala Asp Lys Gin Leu Phe Thr Leu Val Glu Trp Ala Lys Arg He Pro 275 280 285 His Phe Ser Asp Leu Thr Leu Glu Asp Gin Val He Leu Leu Arg Ala 290 295 300 Gly Trp Asn Glu Leu Leu He Ala Ser Phe Ser His Arg Ser Val Ser 305 310 315 320 Val Gin Asp Gly He Leu Leu Ala Thr Gly Leu His Val His Arg Ser 325 330 335 Ser Ala His Ser Arg Gly Val Gly Ser He Phe Asp Arg Val Leu Thr 340 345 350 Glu Leu Val Ser Lys Het Lys Asp Het Gin Het Asp Lys Ser Glu Leu 355 360 365 Gly Cys Leu Arg Ala He Val Leu Phe Asn Pro Asp Ala Lys Gly Leu 370 375 380 Ser Asn Pro Ser Glu Val Glu Thr Leu Arg Glu Lys Val Tyr Ala Thr 385 390 395 400 Leu Glu Ala Tyr Thr Lys Gin Lys Tyr Pro Glu Gin Pro Gly Arg Phe 405 410 415 Ala Lys Leu Leu Leu Arg Leu Pro Ala Leu Arg Ser He Gly Leu Lys 420 425 430 Cys Leu Glu His Leu Phe Phe Phe Lys Leu He Gly Asp Thr Pro He 435 440 445 Asp Ser Phe Leu Het Glu Met Leu Glu Thr Pro Leu Gin He Thr 450 455 460 SEQ ID H0:7: GAATTCCCCC GAAGCCCAGA CAGCTCCTCC CCAAATCCCC TTTCTCAGGG GATCCGTCCG 60 TCTTCTCCTC CTGGCCCACC TCTTACCCCT TCAGCACCTC CACCTCCA ATG CCA CCC 117 Hpt Pro Pro 1 CCG CCA CTG GGC TCC CCC TTC CCA GTC ATC AGT TCT TCC ATG GGG TCC 165 Pro Pro Leu Gly Ser Pro Phe Pro Val He Ser Ser Ser Met Gly Ser 5 10 15 CCT GGT CTG CCC CCT CCG GCT CCC CCA GGA TTC TCC GGG CCT GTC AGC 213 Pro Gly Leu Pro Pro Pro Ala Pro Pro Gly Phe Ser Gly Pro Val Ser 20 25 30 35 AGC CCT CAG ATC AAC TCC ACA GTG TCG CTC CCT GGG GGT GGG TCT GGC 261 Ser Pro Gin He Asn Ser Thr Val Ser Leu Pro Gly Gly Gly Ser Gly 40 45 50 CCC CCT GAA GAT GTG AAG CCA CCG GTC TTλ GGG GTC CGG GGC CTG CAC 309 Pro Pro Glu Asp Val Lys Pro Pro Val Leu Gly Val Arg Gly Leu His 55 60 65 TGT CCA CCC CCT CCA GGT GGT CCT GGG GCT GGC AAA CGG CTC TGT GCA 357 Cys Pro Pro Pro Pro Gly Gly Pro Gly Ala Gly Lys Arg Leu Cys Ala 70 75 80 ATC TGC GGG GAC CGA AGC TCA GGC AAG CAC TAT GGG GTT TAC AGC TGC 405 He Cys Gly Asp Arg Ser Ser Gly Lys His Tyr Gly Val Tyr Ser Cys 85 90 95 GAG GGC TGC AAG GGT TTC TTC AAG CGC ACC ATT CGG AAG GAC CTG ACC 453 Glu Gly Cys Lys Gly Phe Phe Lys Arg Thr He Arg Lys Asp Leu Thr 100 105 110 115 TAC TCG TGT CGT GAT AAC AAA GAC TGT ACA GTG GAC AAG CGC CAG CGG 501 Tyr Ser Cys Arg Asp Asn Lys Asp Cys Thr Val Asp Lys Arg Gin Arg 120 125 130 AAT CGC TGT CAG TAC TGT CGC TAT CAG AAG TGC CTG GCC ACT GGC ATG 549 Asn Arg Cys Gin Tyr Cys Arg Tyr Gin Lys Cys Leu Ala Thr Gly Met 135 140 145 AAA AGG GAG GCG GTT CAG GAG GAG CGT CAA CGG GGG AAG GAC AAA GAC 597 Lys Arg Glu Ala Val Gin Glu Glu Arg Gin Arg Gly Lys Asp Lys Asp 150 155 160 GGG GAT GGA GAT GGG GCT GGG GGA GCC CCT GAG GAG ATG CCT GTG GAC 645 Gly Asp Gly Asp Gly Ala Gly Gly Ala Pro Glu Glu Met Pro Val Asp 165 170 175 AGG ATC CTG GAG GCA GAG CTT GCT GTG GAG CAG AAG AGT GAC CAA GGC 693 Arg He Leu Glu Ala Glu Leu Ala Val Glu Gin Lys Ser Asp Gin Gly 180 1B5 190 195 GTT GAG GGT CCT GGG GCC ACC GGG GGT GGT GGC AGC AGC CCA AAT GAC 741 Val Glu Gly Pro Gly Ala Thr Gly Gly Gly Gly Ser Ser Pro Asn Asp 200 " 205 210 CCA GTG ACT AAC ATC TGC CAG GCA GCT GAC AAA CAG CTG TTC ACA CTC 789 Pro Val Thr Asn He Cys Gin Ala Ala Asp Lys Gin Leu Phe Thr Leu 215 220 225 GTT GAG TGG GCA AAG AGG ATC CCG CAC TTC TCC TCC CTA CCT CTG GAC 837 Val Glu Trp Ala Lys Arg He Pro His Phe Ser Ser Leu Pro Leu Asp 230 235 240 GAT CAG GTC ATA CTG CTG CGG GCA GGC TGG AAC GAG CTC CTC ATT GCG 885 Asp Gin Val He Leu Leu Arg Ala Gly Trp Asn Glu Leu Leu He Ala 245 250 255 TCC TTC TCC CAT CGG TCC ATT GAT GTC CGA GAT GGC ATC CTC CTG GCC 933 Ser Phe Ser His Arg Ser He Asp Val Arg Asp Gly He Leu Leu Ala 260 265 270 275 ACG GGT CTT CAT GTG CAC AGA AAC TCA GCC CAT TCC GCA GGC GTG GGA 981 Thr Gly Leu His Val His Arg Asn Ser Ala His Ser Ala Gly Val Gly 280 285 290 GCC ATC TTT GAT CGG GTG CTG ACA GAG CTA GTG TCC AAA ATG CGT GAC 1029 Ala He Phe Asp Arg Val Leu Thr Glu Leu Val Ser Lys Het Arg Asp 295 300 305 ATG AGG ATG GAC AAG ACA GAG CTT GGC TGC CTG CGG GCA ATC ATA CTG 1077 Met Arg Met Asp Lys Thr Glu Leu Gly Cys Leu Arg Ala He He Leu 310 315 320 TTT AAT CCA GAC GCC AAG GGC CTC TCC AAC CCT GGA GAG GTG GAG ATC 1125 Phe Asn Pro Asp Ala Lys Gly Leu Ser Asn Pro Gly Glu Val Glu He 325 330 335 CTT CGG GAG AAG GTG TAC GCC TCA CTG GAG ACC TAT TGC AAG CAG AAG 1173 Leu Arg Glu Lys Val Tyr Ala Ser Leu Glu Thr Tyr Cys Lys Gin Lys 340 345 350 355 TAC CCT GAG CAG CAG GGC CGG TTT GCC AAG CTG CTG TTA CGT CTT CCT 1221 Tyr Pro Glu Gin Gin Gly Arg Phe Ala Lys Leu Leu Leu Arg Leu Pro 360 365 370 GCC CTC CGC TCC ATC GGC CTC AAG TGT CTG GAG CAC CTG TTC TTC TTC 1269 Ala Leu Arg Ser He Gly Leu Lys Cys Leu Glu His Leu Phe Phe Phe 375 380 385 AAG CTC ATT GGC GAC ACC CCC ATT GAC ACC TTC CTC ATG GAG ATG CTT 1317 Lys Leu He Gly Asp Thr Pro He Asp Thr Phe Leu Het Glu Het Leu 390 395 400 GAG GCT CCC CAC CAG CTA GCC TGAGCCCAGA TGCACACCGA GTGTCACTGA 1368 Glu Ala Pro His Gin Leu Ala 405 410 GGAGGACTTG AGCCTGGGCA GGGGGCAGAG CCATGGGACA GGTGCAGAGC AGGAGGGGAC 1428 TTGCCCAGCC TGCCAGGGAT CTGGCAACAC TTAGCAGGGT TCGCTTGGTC TCCAAGTCGA 1488 AGGGGACCCC AGATCCCTGT GAGGACTTTA TGTCTACCTT CAGTGGCCTT GAGTCTCTGA 1548 ATTTGTCGGG GTCTCCCATG GTGCAGGTGA TTCTTCATCC TGGCTCCCCA GCACAAAGCA 1608 CTGCCCTGCT TCCTTCTCAT TTGGCCTCAC TCCCTTCTGA AGAGTGGAAC AGAGCTCCCC 1668 CAGAAAGGGG TGTTGTGGGG CAGGCCCCCC AAGCTGATGA TCATGGGAGC AGGGCTCTGA 1728 CAGCCTTTAT CCTCTCAGAC TTGACAGATG GGGGCAGAGG AGGGACCTGC CTCTGTCTCC 17B8 TGTCAGCCCC ATTTCCACAG TCCCTCCTGC AGTCAGACTG AAGAATAAAG GGGTAGTGAA 1848 GGGGCTGCTG GAGGTGGAGG AACCCATTGC TCTTTTAATT TCCTGTGAGG AGAGACTGGG 1908 AGTTAGACTC AAAGAAGTAC TGTACATCCC CAGGTTGACT TAAATGTCAG GGCTGGAGAT 1968 GGCATGTGGG CAAGGAGGCC CCTCAGGTGG GCTGTCCCAA AGCTCCCTGG GCTCTGCCTC 2028 GGGTGGCCCT ACAGCTCTTC CCTAGTCTTA AGCACAGCTA GGCTGGGAGC AAGTGGGGAC 2088 ATTGATGGGG GTGGCCAGCC TGCAGAGTTG GGTGCTGGGC TGCATGGTTT TTGCCCTGGA 2148 CCTCTTTTGG GGGTTCCCTC CCATCTTTCA CTTGCACATA AAGTTGCTTT CCAGTTAAAA 2208 AAAAAAAAAA A 2219

Claims: CLAIMS That which is claimed is: 1. A substantially pure DNA sequence which encodes a polypeptide, wherein said polypeptide is characterized by: (1) being responsive to the presence of retinoid(s) to regulate the transcription of associated gene(ε) ; (2) having a DNA binding domain of about 66 amino acids with 9 Cys residues, wherein said DNA binding domain has: (a) less than about 65 % amino acid identity with the DNA binding domain of hRAR-alpha, (b) less than about 55 % amino acid identity with the DNA binding domain of hTR-beta, and (c) less than about 55 % amino acid identity with the DNA binding domain of hGR; and (3) not including the sequence set forth in Sequence ID No 7. 2. A DNA sequence- according to Claim 1 wherein said polypeptide is encoded by a continuous sequence which encodes substantially the same sequence as that of: amino acids 1 - 462 shown in Sequence ID No. 2 [hRXR-α], amino acids 1 - 467 shown in Sequence ID No. 4 [mRXR-α], or amino acids 1 - 463 shown in Sequence ID No. 6 [mRXR-γ] . 3. A DNA sequence according to Claim 1 wherein said polypeptide is encoded by a continuous sequence which encodes substantially the same sequence as that of: amino acids 135 - 200 shown in Sequence ID No. 2 [hRXR-α] , amino acids 140 - 205 shown in Sequence ID No. 4 [mRXR-α] , or amino acids 139 - 204 shown in Sequence ID No. 6 [mRXR-γ] . 4. A DNA sequence according to Claim 1 which comprises a segment having a continuous nucleotide sequence which is substantially the same as: nucleotides 76 - 1464 shown in Sequence ID No. 1 [hRXR-α] , nucleotides 181 - 1581 shown in Sequence ID No. 2 [mRXR-α] , or nucleotides 123 - 1514 shown in Sequence ID No. 3 [mRXR-γ] . 5. A DNA sequence according to Claim 4 which is pSK(hRXR-alpha) , pSK(mRXR-alpha) , or pSK(mRXR-gamma) . 6. A substantially pure DNA construct comprising: (i) the DNA sequence of Claim 1 operatively linked to (ii) regulatory element(s) operative for transcription of said DNA sequence and expression of said polypeptide in an animal cell in culture. 7. A DNA construct according to Claim 6 which is selected from A5C-hRXR-alpha, A5C-mRXR-alpha, A5C-mRXR-gamma, RS-hRXR-alpha, RS-mRXR-alpha, or RS-mRXR-gamma. 8. An animal cell in culture which is transformed with a DNA construct according to Claim 6. 9. A cell according to Claim 8 wherein said cell is an insect cell or a mammalian cell. 10. A cell according to Claim 9 wherein the DNA construct is selected from A5C-hRXR-alpha, A5C-mRXR- alpha, A5C-mRXR-gamma, RS-hRXR-alpha, RS-mRXR-alpha, or RS-mRXR-gamma. 11. A cell according to Claim 8, wherein said cell is further transformed with a reporter vector which comprises: (a) a promoter that is operable in said cell, (b) a hormone response element, and (c) a DNA segment encoding & reporter protein, wherein said reporter protein-encoding DNA segment is operatively linked to said promoter for transcription of said DNA segment, and wherein said hormone response element is operatively linked to said promoter for activation thereof. 12. A cell according to Claim 11 wherein: the promoter is the 5'-LTR promoter of a mouse mammary tumor virus, the hormone response element is selected from TRE or beta-RARE, and the reporter protein is selected from chloramphenicol acetyltransferase, luciferase, or beta-galactosidase. 13. A cell according to Claim 12 wherein the reporter vector is selected from delta-MTV-TRE -CAT, delta-TK-TRE P-CAT,' delta-SV-TREP-CAT,' delta-MTV-TREP-LUC,' delta-TK-TREp-LUC, or delta-SV-TREp-LUC. 14. A cell according to Claim 12 wherein the reporter vector is selected from ADH-TRE -CAT, ADH-TRE - LUC,' TK-TREP-CAT, or TK-TREP-LUC. 15. A cell according to Claim 14 which is a Drosophila melanogaster Schneider line 2 cell. 16. A method of testing a compound for its ability to regulate transcription-activating effects of a receptor polypeptide, said method comprising assaying for the presence or absence of reporter protein upon contacting of cells containing a receptor polypeptide and reporter vector with said compound; wherein said receptor polypeptide is characterized by: (1) being responsive to the presence of retinoid(s) to regulate the transcription of associated gene(s) ; and (2) having a DNA binding domain of about 66 amino acids with 9 Cys residues, wherein said DNA binding domain has: (a) less than about 65 % amino acid identity with the DNA binding domain of hRAR-alpha, (b) less than about 55 % amino acid identity with the DNA binding domain of hTR-beta, and (c) less than about 55 % amino acid identity with the DNA binding domain of hGR, and wherein said reporter vector comprises: (a) a promoter that is operable in said cell, (b) a hormone response element, and (c) a DNA segment encoding a reporter protein, wherein said reporter protein-encoding DNA seqπient is operatively linked to said promoter for transcription of said DNA segment, and wherein said hormone response element is operatively linked to said promoter for activation thereof. 17. A method according to Claim 16 wherein said contacting is carried out in the further presence of at least one retinoid species. 18. A method according to Claim 16 wherein the cells employed are CV-1 cells co-trsnsforτr'<?d wi th e vector capable of expressing said receptor polypeptide, wherein said vector is selected from RS-hRXR-alpha, RS- mRXR-alpha, or RS-mRXR-gamma and a reporter vector selected from delta-MTV-TRE p -CAT, delta-TK-TRE p -CAT, delta-SV-TRE P-CAT, delta-MTV-TREP-LUC,' delta-TK-TREP-LUC,' or delta-SV-TRE p -LUC. 19. A method according to Claim 16 wherein the cells employed are Drosophila melanogaster Schneider line 2 cells co-transformed with a vector capable of expressing said receptor polypeptide, wherein said vector is selected from A5C-hRXR-alpha, A5C-mRXR-alpha, or A5C- mRXR-gamma, and a reporter vector selected from ADH-TRE - CAT, i ADH-TREP-LUC,' TK-TREP-CAT, or TK-TREP-LUC. 20. A labeled single-stranded nucleic acid sequence, comprising at least 20 contiguous bases in length having substantially the same sequence as any 20 or more contiguous bases selected from: (i) bases 2 - 1861, inclusive, of the DNA illustrated in Sequence ID No. 1 [hRXR-α], or (ii) bases 20 - 2095, inclusive, of the DNA illustrated in Sequence ID No. 2 [mRXR-α] , or (iii) bases 15 - 1653, inclusive, of the DNA illustrated in Sequence ID No. 3 [mRXR-γ] , or (iv) the complement of any one of the sequences according to (i) , (ii) , or (iii) . 21. A nucleic acid according to Claim 20 which is labelled with 32 P. 22. A method of making a receptor polypeptide, wherein said polypeptide is characterized by: (1) being responsive to the presence of retinoid(s) to regulate the transcription of associated „ „ f m. \ . -, > ,_^ (2) having a DNA binding domain of about 66 amino acids with 9 Cys residues, wherein said DNA binding domain has: (a) less than about 65 % amino acid identity with the DNA binding domain of hRAR-alpha, (b) less than about 55 % amino acid identity with the DNA binding domain of hTR-beta, and (c) less than about 55 % amino acid identity with the DNA binding domain of hGR; said method comprising culturing cells containing an expression vector operable in said cells to express a DNA sequence encoding said polypeptide. 23. A method according to Claim 22 wherein said receptor polypeptide has substantially the same sequence as that of: amino acids 1 - 462 shown in Sequence ID No. 2 [hRXR-α] , amino acids 1 - 467 shown in Sequence ID No. 4 [mRXR-α] , or amino acids 1 - 463 shown in Sequence ID No. 6 [mRXR-γ] . 24. A method according to Claim 22 wherein said receptor polypeptide comprises a DNA binding domain with substantially the same sequence as that of: amino acids 135 - 200 shown in Sequence ID No. 2 [hRXR-α] , amino acids 140 - 205 shown in Sequence ID No. 4 [mRXR-α], or amino acids 139 - 204 shown in Sequence ID No. 6 [mRXR-γ]. 25. A method according to Claim 22 wherein said DNA sequence comprises a segment with substantially the same nucleotide sequence as that of: nucleotides 76 - 1464 shown in Sequence ID No. 1 [hRXR-α], nucleotides 181 - 1581 shown in Sequence ID No. 2 [mRXR-α], or nucleotides 123 - 1514 shown in Sequence ID No. 3 [mRXR-γ].

Inventors: EVANS RONALD MARK, MANGELSDORF DAVID JOHN, EVANS, RONALD, MARK, MANGELSDORF, DAVID, JOHN
Applicants: SALK INST FOR BIOLOGICAL STUDI, THE SALK INSTITUTE FOR BIOLOGICAL STUDIES
Application year: 1991
Main classification: C07K3
IPC codes: C07H21, C07K14, C12N5, C12N15, C12P21, C12Q1, C12R1