Patent ID: 7067260

Claim:
A method for identifying a binding analog for a morphogen receptor, said morphogen sharing at least 60% amino acid sequence identity or at least 70% amino acid sequence homology with the sequence of the C-terminal 102 amino acid of SEQ ID NO: 7, and being able to substitute for OP-1 in binding to a protein comprising SEQ ID NOs. 4, 6, or 8, said binding analog having substantially the same binding affinity for said morphogen receptor as said morphogen, the method comprising: (a) providing a sample without a Type II serine/threonine kinase morphogen receptor but containing a protein selected from: (i) a polypeptide comprising an amino acid sequence defined by residues 16-123 of SEQ ID NO: 4 (ALK-2); (ii) a polypeptide comprising an amino acid sequence defined by residues 24-152 of SEQ ID NO: 6 (ALK-3); (iii) a polypeptide comprising an amino acid sequence defined by residues 23-122 of SEQ ID NO: 8 (ALK-6); or (iv) a polypeptide having binding affinity for OP-1 and encoded by a first nucleic acid capable of hybridizing under stringent conditions with a second nucleic acid comprising the sequence defined by nucleotides 256-552 of SEQ ID NO: 7 (ALK-6), the stringent conditions being hybridization in 40% formamide 5×SSPE, 5×Denhardt's Solution, 0.1% SDS at 37° C. overnight, then washing in 0.1×SSPE, 0.1% SDS at 50° C.; (b) contacting said sample with a candidate morphogen receptor-binding analog; and (c) detecting specific binding between said candidate morphogen receptor-binding analog and said protein; wherein binding of said candidate morphogen receptor-binding analog to said protein is indicative that said candidate analog is a morphogen receptor-binding analog.