Growth factor which acts through erb b-4 rtk

Abstract

The present invention provides for isolated polypeptides capable of binding ErbB-4.

1 . A method of regulating an endogenous protein activity affecting ErbB-4 activity in a cell, the method comprising the steps of contacting the cell with an agent for regulating the endogenous protein activity, the endogenous protein being at least 95% homologous to positions 4-50 of SEQ ID NO: 15 as determined using the BestFit software of the Wisconsin sequence analysis package, utilizing the Smith and Waterman algorithm, where gap creation penalty equals 8 and gap extension penalty equals 15, said polypeptide being capable of binding ErbB-4. 
     
     
         2 . The method of  claim 1 , wherein said agent serves to upregulate the endogenous protein activity. 
     
     
         3 . The method of  claim 2 , wherein said agent is a polynucleotide at least 95% identical with SEQ ID NOs:1 or 14 as determined using the BestFit software of the Wisconsin sequence analysis package, utilizing the Smith and Waterman algorithm, where gap weight equals 50, length weight equals 3, average match equals 10 and average mismatch equals -9. 
     
     
         4 . The method of  claim 2 , wherein said agent is a polypeptide at least 95% homologous to positions 4-50 of SEQ ID NO: 15 as determined using the BestFit software of the Wisconsin sequence analysis package, utilizing the Smith and Waterman algorithm, where gap creation penalty equals 8 and gap extension penalty equals 15, said polypeptide being capable of binding ErbB-4 
     
     
         5 . The method of  claim 1 , wherein said agent serves to downregulate the endogenous protein activity. 
     
     
         6 . The method of  claim 5 , wherein said agent is an antibody that specifically recognizes a polypeptide being at least 95% homologous to positions 4-50 of SEQ ID NO: 15 as determined using the BestFit software of the Wisconsin sequence analysis package, utilizing the Smith and Waterman algorithm, where gap creation penalty equals 8 and gap extension penalty equals 15, said polypeptide being capable of binding ErbB-4. 
     
     
         7 . The method of  claim 6 , wherein the antibody is selected from the group consisting of a polyclonal antibody, a monoclonal antibody, a humanized antibody and a single chain antibody. 
     
     
         8 . The method of  claim 6 , wherein said antibody specifically recognizes positions 4-50 of SEQ ID NO:2. 
     
     
         9 . The method of  claim 5 , wherein said agent includes an expressible antisense polynucleotide at least 95% identical with SEQ ID NOs:1 or 14 as determined using the BestFit software of the Wisconsin sequence analysis package, utilizing the Smith and Waterman algorithm, where gap weight equals 50, length weight equals 3, average match equals 10 and average mismatch equals −9.