Cloning and recombinant production of CRF receptor(s)

Abstract

In accordance with the present invention, there are provided novel receptor proteins characterized by having the following domains, reading from the N-terminal end of said protein: an extracellular, ligand-binding domain, a hydrophobic, trans-membrane domain, and an intracellular, receptor domain having serine kinase-like activity. The invention receptors optionally further comprise a second hydrophobic domain at the amino terminus thereof. The invention receptor proteins are further characterized by having sufficient binding affinity for at least one member of the activin/TGF-β superfamily of polypeptide growth factors such that concentrations of ≦10 nM of said polypeptide growth factor occupy ≦50% of the binding sites of said receptor protein. A presently preferred member of the invention superfamily of receptors binds specifically to activins, in preference to inhibins, transforming growth factor-β, and other non-activin-like proteins. DNA sequences encoding such receptors, assays employing same, as well as antibodies derived therefrom, are also disclosed.

1 - 17 . (canceled)  
     
     
         18 . A method for enhancing the survival of neurons in a subject in need thereof, the method comprising administering to the subject an effective amount of a polypeptide selected from the group consisting of: 
 a polypeptide comprising a soluble, extracellular domain of a type II activin receptor (ActRII); and    a polypeptide comprising a soluble, extracellular domain of an activin receptor-like kinase 7 (ALK7) receptor.    
     
     
         19 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:12.  
     
     
         20 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of residues 26-113 of SEQ ID NO:12.  
     
     
         21 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having substantial sequence identity with respect to the amino acid sequence of residues 26-113 of SEQ ID NO:12.  
     
     
         22 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having the same amino acid sequence as the amino acid sequence of residues 26-113 of SEQ ID NO:12.  
     
     
         23 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:2.  
     
     
         24 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:16.  
     
     
         25 . The method of  claim 18 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:4.  
     
     
         26 . The method of  claim 18 , wherein the polypeptide has sufficient binding affinity for at least one member of the activin/TGF-β superfamily of polypeptide growth factors such that concentrations of 10 nM of said polypeptide growth factor occupy at least 50% of the binding sites on said polypeptide.  
     
     
         27 . A method for the treatment of an activin-dependent tumor in a subject in need thereof, the method comprising, administering to the subject an effective amount of a polypeptide selected from the group consisting of: 
 a polypeptide comprising a soluble, extracellular domain of a type II activin receptor (ActRII); and    a polypeptide comprising a soluble, extracellular domain of an activin receptor-like kinase 7 (ALK7) receptor.    
     
     
         28 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:12.  
     
     
         29 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of residues 26-113 of SEQ ID NO:12.  
     
     
         30 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having substantial sequence identity with respect to the amino acid sequence of residues 26-113 of SEQ ID NO:12.  
     
     
         31 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having the same amino acid sequence as the amino acid sequence of residues 26-113 of SEQ ID NO:12.  
     
     
         32 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:2.  
     
     
         33 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:16.  
     
     
         34 . The method of  claim 27 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:4.  
     
     
         35 . The method of  claim 27 , wherein the polypeptide has sufficient binding affinity for at least one member of the activin/TGF-.beta. superfamily of polypeptide growth factors such that concentrations of 10 nM of said polypeptide growth factor occupy at least 50% of the binding sites on said polypeptide.  
     
     
         36 . A method for enhancing the survival of neurons in a subject in need thereof, the method comprising administering to the subject an effective amount of an antibody, or antigen binding portion thereof, that binds selectively to a polypeptide having an amino acid sequence selected from the group consisting of: 
 residues 26-113 of SEQ ID NO:12;    residues 20-134 of SEQ ID NO:16;    residues 20-134 of SEQ ID NO:2; and    residues 21-132 of SEQ ID NO:4.    
     
     
         37 . The method of  claim 36 , wherein the antibody is a monoclonal antibody.  
     
     
         38 . A method for the treatment of an activin-dependent tumor in a subject in need thereof, the method comprising administering to the subject an effective amount of an antibody, or antigen binding portion thereof, that binds selectively to a polypeptide having an amino acid sequence selected from the group consisting of: 
 residues 26-113 of SEQ ID NO:12;    residues 20-134 of SEQ ID NO:16;    residues 20-134 of SEQ ID NO:2; and    residues 21-132 of SEQ ID NO:4.    
     
     
         39 . The method of  claim 38 , wherein the antibody is a monoclonal antibody.  
     
     
         40 . A method for inhibiting signal transduction mediated by an activin receptor-like kinase 7 (ALK7) receptor in cells, the method comprising exposing the cells to an effective amount of a polypeptide comprising a soluble extracellular domain of ALK7.  
     
     
         41 . The method of  claim 40 , wherein the cells are cultured cells.  
     
     
         42 . The method of  claim 40 , wherein the cells are situated in a subject, and wherein exposing the cells to the polypeptide comprises administering the polypeptide to the subject by a modality selected from the group consisting of: intraperitoneal injection, intramuscular injection, intravenous injection, and subcutaneous injection.  
     
     
         43 . The method of  claim 40 , wherein the cells are muscle cells.  
     
     
         44 . The method of  claim 43 , wherein exposing the cells to the polypeptide causes an increase in muscle specific actin expression in the cells.  
     
     
         45 . The method of  claim 40 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:12.  
     
     
         46 . A method for inhibiting signal transduction mediated by a type II activin receptor (ActRII) in cells, the method comprising exposing the cells to an effective amount of a polypeptide comprising a soluble extracellular domain of an ActRII.  
     
     
         47 . The method of  claim 46 , wherein the cells are cultured cells.  
     
     
         48 . The method of  claim 46 , wherein the cells are situated in a subject, and wherein exposing the cells to the polypeptide comprises administering the polypeptide to the subject by a modality selected from the group consisting of: intraperitoneal injection, intramuscular injection, intravenous injection, and subcutaneous injection.  
     
     
         49 . The method of  claim 46 , wherein the cells are muscle cells.  
     
     
         50 . The method of  claim 49 , wherein exposing the cells to the polypeptide causes an increase in muscle specific actin expression.  
     
     
         51 . The method of  claim 46 , wherein the polypeptide comprises an amino acid sequence having at least 80% identity with respect to the amino acid sequence of an extracellular domain as set forth in SEQ ID NO:16, SEQ ID NO:2 or SEQ ID NO:4.