Binding proteins that bind to her - 3 and polynucleotides encoding the same. Also provides Expression Vectors and host cells comprising the same for the production of the binding protein of the invention.Also provides compositions and Methods for Diagnosing and Treating Diseases associated with Signal Transduction mediated by her - 3 and \/ or its ligand heregulin claim 1.- A protein that binds to her isolated Union - 3, characterized in that it comprises: an amino acid sequence of heavy chain comprising at least one of the RDFS, selected from the group consisting of (a) cdrh1s as shown in SEQ ID Nos: 2, 6, 10, 14, 18, 22, 26, 30, 34 , 36, 40, 42, 46, 50, 54, 60, 62, 66, 70, 74, 78, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120,122, 126, 130, 134, 138, 142, 146, 150, 154, 156, 162, 165, 170, 174, 176, 182, 186, 190, 194, 198, 202, 206, 210, 214, 218, 222, 226 and 230 (b), as shown in cdrh2s the SEQ ID Nos: 2, 6, 10, 14, 18, 22, 26, 30, 34, 36, 40, 42, 46, 50, 54, 60, 62, 66, 70, 74, 78, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 122, 126, 130, 134, 138, 142, 146, 150, 154, 156, 162, 165, 170, 174, 176, 178,186, 190, 194, 198, 202, 206, 210, 214, 218, 222, 226 and 230, and (c) cdrh3s as shown in SEQ ID Nos: 2, 6, 10, 14, 18, 22, 26, 30, 34, 36, 40, 42, 46, 50, 54, 60, 62, 66, 70, 74, 78, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 122, 126, 130, 134, 138, 142, 146, 150, 154, 156, 162, 16 6, 170, 174, 176, 182, 186, 190, 194, 198, 202, 206, 210, 214, 218, 222, 226 and 230.Claim in the method according to claim 46 or 47, wherein Said hiperproliferativa disease is associated with increased phosphorylation of bro - 3, increased heterodimerization of her-2 \/ her 3 or increased activity of PI3 kinase, c-jun terminal kinase, AKT, and And \/ or pyr2 RK2.Proteínas de union que se unen a HER-3 y polinucleotidos que codifican a las mismas. También se proveen los vectores de expresion y las células huésped que comprenden las mismas para la produccion de la prote
