Identification of c-erbB-3 binding sites for phosphatidylinositol 3'-kinase and SHC using an EGF receptor/c-erbB-3 chimera.
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.
Molecular Oncology Laboratory, Hammersmith Hospital, London, UK.
S A
SA
Prigent
W J
WJ
Gullick
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D002448:Cell Adhesion; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D051380:GRB2 Adaptor Protein; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D019869:Phosphatidylinositol 3-Kinases; D010748:Phosphopeptides / Q000235:genetics; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015290:Second Messenger Systems
D048868:Adaptor Proteins, Signal Transducing; D030161:Avian Proteins; D003598:Cytoskeletal Proteins; D051380:GRB2 Adaptor Protein; D010748:Phosphopeptides; D010750:Phosphoproteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; C071033:cytoskeletal p85 protein, chicken; D005982:Glutathione Transferase; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D066246:ErbB Receptors