14273 receptor, a novel G-protein coupled receptor

Abstract

The present invention relates to a newly identified receptor belonging to the superfamily of G-protein-coupled receptors. The invention also relates to polynucleotides encoding the receptor. The invention further relates to methods using the receptor polypeptides and polynucleotides as a target for diagnosis and treatment in receptor-mediated disorders, specifically, cardiovascular diseases, including congestive heart failure. The invention further relates to drug-screening methods using the receptor polypeptides and polynucleotides to identify agonists and antagonists for diagnosis and treatment. The invention further encompasses agonists and antagonists based on the receptor polypeptides and polynucleotides. The invention further relates to procedures for producing the receptor polypeptides and polynucleotides.

1 . A method for identifying a compound capable of modulating an activity of a polypeptide selected from the group consisting of:
 (a) an isolated polypeptide comprising the amino acid sequence shown in SEQ ID NO:1 or SEQ ID NO:4;   (b) an isolated polypeptide comprising the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:2, SEQ ID NO:5, or the cDNA contained in ATCC Deposit No. PTA-1143; and   (c) an isolated polypeptide comprising an amino acid sequence that is at least 95% identical to the amino acid sequence shown in SEQ ID NO:1 or SEQ ID NO:4; the method comprising:   i) contacting the polypeptide, or a cell expressing the polypeptide with a test compound under conditions that allow the compound to modulate the activity of the polypeptide,   ii) determining the effect of the test compound on activity of the polypeptide, wherein the activity is selected from the group consisting of:
 1) binding to a G protein in response to ligand binding; 
 2) receptor protein phosphorylation in response to ligand binding; 
 3) binding to a ligand; 
 4) stimulation or inhibition of intracellular calcium concentration; 
 5) stimulation or inhibition of intracellular cAMP concentration; 
 6) stimulation or inhibition of adenylate cyclase activity; and 
 7) stimulation or inhibition of phospholipase C activity; 
   
       thereby identifying a compound capable of modulating the activity of the polypeptide. 
     
     
         2 . The method of  claim 1 , wherein the compound is selected from the group consisting of a peptide, phosphopeptide, antibody, and a small molecule. 
     
     
         3 . A method for identifying a compound which binds to a polypeptide selected from the group consisting of:
 (a) an isolated polypeptide comprising the amino acid sequence shown in SEQ ID NO:1 or SEQ ID NO:4;   (b) an isolated polypeptide comprising the amino acid sequence encoded by the nucleotide sequence of SEQ ID. NO:2, SEQ ID NO:5, or the cDNA contained in ATCC Deposit No. PTA-1143; and   (c) an isolated polypeptide comprising an amino acid sequence that is at least 95% identical to the amino acid sequence shown in SEQ ID NO:1 or SEQ ID NO:4, the method comprising:   i) contacting the polypeptide, or a cell expressing the polypeptide with a test compound under conditions that allow the compound to bind the polypeptide,   ii) detecting the binding of the test compound to the polypeptide, thereby identifying a compound which binds the polypeptide.   
     
     
         4 . The method of  claim 3 , wherein the binding of the test compound to the polypeptide is detected by a method selected from the group consisting of:
 a) direct detection of test compound/polypeptide binding;   b) a competition binding assay; and   c) an immunoassay;   
     
     
         5 . The method of  claim 3 , wherein the test compound is selected from the group consisting of a peptide, phosphopeptide, antibody, and a small molecule. 
     
     
         6 . The method of  claim 3 , wherein the test compound is labeled. 
     
     
         7 . An isolated antibody or fragment thereof which specifically binds to a polypeptide selected from the group consisting of:
 (a) an isolated polypeptide comprising the amino acid sequence shown in SEQ ID NO:1 or SEQ ID NO:4;   (b) an isolated polypeptide comprising the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:2, SEQ ID NO:5, or the cDNA contained in ATCC Deposit No. PTA-1143;   (c) an isolated polypeptide comprising an amino acid sequence that is at least 95% identical to the amino acid sequence shown in SEQ ID NO:1 or SEQ ID NO:4; and   (d) an isolated polypeptide comprising a fragment of at least 6 consecutive amino acids of the amino acid sequence of SEQ ID NO:1, SEQ ID NO:4, or a fragment of at least 6 consecutive amino acids of the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:2, SEQ ID NO:5, or the cDNA contained in ATCC Deposit No. PTA-1143.   
     
     
         8 . The antibody or fragment thereof of  claim 7 , wherein the antibody is detectably labeled. 
     
     
         9 . The antibody or fragment thereof of  claim 8 , wherein the detectable label is selected from the group consisting of:
 a) enzymes;   b) prosthetic groups;   c) fluorescent materials;   d) luminescent materials;   e) bioluminescent materials; and   f) radioactive materials.   
     
     
         10 . The antibody or fragment thereof of  claim 7 , wherein the antibody or fragment thereof is selected from the group consisting of:
 a) monoclonal antibody;   b) polyclonal antibody;   c) Fab fragment; and   d) F(ab′) 2  fragment.   
     
     
         11 . The antibody or fragment thereof of  claim 7 , wherein the antibody or fragment thereof specifically binds to amino acids 348-361 of SEQ ID NO:1, or to amino acids 348-361 of the amino acid sequence encoded by the nucleotide sequence of SEQ ID NO:2, SEQ ID NO:5, or the cDNA contained in ATCC Deposit No. PTA-1143.