The phosphotyrosine interaction domain of Shc binds an LXNPXY motif on the epidermal growth factor receptor.
Shc is an SH2 domain protein that is tyrosine phosphorylated in cells stimulated with a variety of growth factors and cytokines. Once phosphorylated, Shc binds the Grb2-Sos complex, leading to Ras activation. Shc can interact with tyrosine-phosphorylated proteins by binding to phosphotyrosine in the context of an NPXpY motif, where pY is a phosphotyrosine. This is an unusual binding site for an SH2 domain protein whose binding specificity is usually controlled by residues carboxy terminal, not amino terminal, to the phosphotyrosine. Recently we identified a second region in Shc, named the phosphotyrosine interaction (PI) domain, and we have found it to be present in a variety of other cellular proteins. In this study we used a dephosphorylation protection assay, competition analysis with phosphotyrosine-containing synthetic peptides, and epidermal growth factor receptor (EGFR) mutants to determine the binding sites of the PI domain of Shc on the EGFR. We demonstrate that the PI domain of Shc binds the LXNPXpY motif that encompasses Y-1148 of the activated EGFR. We conclude that the PI domain imparts to Shc its ability to bind the NPXpY motif.
Batzer
A G
AG
Department of Pharmacology, New York University Medical Center, New York, USA.
Blaikie
P
P
Nelson
K
K
Schlessinger
J
J
Margolis
B
B
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D051380:GRB2 Adaptor Protein; D008954:Models, Biological; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; D010446:Peptide Fragments; D011506:Proteins; D011993:Recombinant Fusion Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D066246:ErbB Receptors; D016392:Proto-Oncogene Proteins pp60(c-src)