Identification of c‐erbB‐3 binding sites for phosphatidylinositol 3′‐kinase and SHC using an EGF receptor/c‐erbB‐3 chimera

• Published in: The EMBO journal Vol. 13; no. 12; pp. 2831 - 2841
• Main Authors: Prigent, S.A., Gullick, W.J.
• Format: Journal Article
• Language: English
• Published: England 15.06.1994
• Subjects: Adaptor Proteins, Signal Transducing; Amino Acid Sequence; Animals; Avian Proteins; Base Sequence; Cell Adhesion; Cells, Cultured; Cytoskeletal Proteins - metabolism; ErbB Receptors - genetics; ErbB Receptors - metabolism; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; GRB2 Adaptor Protein; Molecular Sequence Data; Phosphatidylinositol 3-Kinases; Phosphopeptides - genetics; Phosphoproteins - metabolism; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor) - metabolism; Protein Binding; Proteins - genetics; Proteins - metabolism; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins - metabolism; Recombinant Fusion Proteins - metabolism; Second Messenger Systems
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1994.tb06577.x

c‐erbB‐3 is a member of the type I (EGF receptor‐related) family of growth factor receptors for which no ligand has been identified. To facilitate ligand stimulation we have constructed a chimeric receptor which possesses an activatable kinase and promotes the growth of NIH 3T3 fibroblasts. In this study we have shown that SHC and phosphatidylinositol 3′‐kinase bind to the activated EGF receptor/c‐erbB‐3 chimera. Whereas p85 is not phosphorylated to a significant extent, SHC appears to be a major substrate for phosphorylation on tyrosine. In contrast to EGF receptor and c‐erbB‐2, we were unable to detect binding of activated c‐erbB‐3 to GRB2. Using synthetic peptides corresponding to each of 13 potential phosphorylation sites on c‐erbB‐3, we have shown that tyrosine 1309 is responsible for SHC binding. Peptides containing the motif YXXM inhibit p85 association. By comparison with recently reported SHC binding sites on Middle T antigen and Trk we have identified a SHC binding motif, NPXY.