Polynucleotides encoding a class II cytokine receptor

Abstract

Novel receptor polypeptides, polynucleotides encoding the polypeptides, and related compositions and methods are disclosed. The polypeptides comprise an extracellular domain of a cell-surface receptor that is expressed in kidneys, pancreas, prostate, adrenal cortex and nervous tissue. The polypeptides may be used within methods for detecting ligands that promote the proliferation and/or differentiation of these organs.

1 . An isolated polynucleotide encoding a ligand-binding receptor polypeptide, said polypeptide comprising a sequence of amino acids selected from the group consisting of: 
 (a) residues 30 to 250 of SEQ ID NO:2;    (b) allelic variants of (a); and    (c) sequences that are at least 80% identical to (a) or (b).    
     
     
         2 . An isolated polynucleotide according to  claim 1  wherein said polypeptide further comprises a transmembrane domain.  
     
     
         3 . An isolated polynucleotide according to  claim 2  wherein said transmembrane domain comprises residues 251 to 274 of SEQ ID NO:2, or an allelic variant thereof.  
     
     
         4 . An isolated polynucleotide according to  claim 2  wherein said polypeptide further comprises an intracellular domain.  
     
     
         5 . An isolated polynucleotide according to  claim 4  wherein said intracellular domain comprises residues 275 to 553 of SEQ ID NO:2, or an allelic variant thereof.  
     
     
         6 . An isolated polynucleotide according to  claim 1  which is a DNA as shown in SEQ ID NO:1 from nucleotide 339 to nucleotide 1009.  
     
     
         7 . An isolated polynucleotide according to  claim 1  wherein said polypeptide further comprises an affinity tag.  
     
     
         8 . An isolated polynucleotide according to  claim 7  wherein said affinity tag is polyhistidine, protein A, glutathione S transferase, substance P, or an immunoglobulin heavy chain constant region.  
     
     
         9 . An isolated polynucleotide according to  claim 1  wherein said polynucleotide is DNA.  
     
     
         10 . An isolated polynucleotide encoding a polypeptide selected from a group defined SEQ ID NO:2 consisting of residues 1 to 250, residues 1 to 274, residues 1 to 553, residues 2 to 250, residues 2 to 274, residues 2 to 553, residues 251 to 274, residues 251 to 553 and residues 275 to 553.  
     
     
         11 . An expression vector comprising the following operably linked elements: 
 a transcription promoter;    a DNA segment encoding a ligand-binding receptor polypeptide, said polypeptide comprising a sequence of amino acids selected from the group consisting of: 
 (a) residues 30 to 250 of SEQ ID NO:2;  
 (b) allelic variants of (a); and  
 (c) sequences that are at least 80% identical to (a) or (b); and  
   a transcription terminator.    
     
     
         12 . An expression vector according to  claim 11  wherein said polypeptide further comprises a signal sequence.  
     
     
         13 . An expression vector according to  claim 11  wherein said polypeptide further comprises a transmembrane domain.  
     
     
         14 . An expression vector according to  claim 11  wherein said transmembrane domain comprises residues 251 to 274 of SEQ ID NO:2, or an allelic variant thereof.  
     
     
         15 . An expression vector according to  claim 13  wherein said polypeptide further comprises an intracellular domain.  
     
     
         16 . An expression vector according to  claim 15  wherein said intracellular domain comprises residues 275 to 553 of SEQ ID NO:2, or an allelic variant thereof.  
     
     
         17 . An expression vector comprising the following operably linked elements: 
 (a) a transcription promoter;    (b) a DNA segment encoding a chimeric polypeptide, wherein said chimeric polypeptide is comprised of a first portion and a second portion joined by a peptide bond, said first portion consisting essentially of a ligand binding domain of a receptor polypeptide selected from the group consisting of: 
 (i) a receptor polypeptide as shown in SEQ ID NO:2;  
 (ii) allelic variants of SEQ ID NO:2; and  
 (iii) receptor polypeptides that are at least 80% identical to (i) or (ii), and said second portion consisting essentially of an affinity tag; and  
   (c) a transcription terminator.    
     
     
         18 . An expression vector according to  claim 17  wherein said affinity tag is an immunoglobulin F c  polypeptide.  
     
     
         19 . A transformed or transfected cell into which has been introduced an expression vector according to  claim 11 , wherein said cell expresses a receptor polypeptide encoded by the DNA segment.  
     
     
         20 . The cell of  claim 19  wherein said cell is prokaryotic.  
     
     
         21 . The cell of  claim 19  wherein said cell is eukaryotic.