A glycoprotein in the plasma membrane matrix as a major potential substrate of p60v-src.
A potential substrate of p60v-src in Rous sarcoma virus-transformed cells was found to be a 130-kilodalton (kDa) glycoprotein which binds to lectin-Sepharose and can be immunoprecipitated by an anti-phosphotyrosine antibody. This glycoprotein was shown to be distinct from the fibronectin receptor and a cellular protein phosphorylated in p60v-src immune complexes. The protein was a transmembrane protein localized in the plasma membrane and resistant to extraction with Triton X-100. The 130-kDa protein was also highly phosphorylated in cells transformed by Fujinami sarcoma virus or Y73 but not in cells infected with Rous sarcoma virus mutants that encode p60v-src lacking myristoylated N termini. Phosphorylation of this glycoprotein was temperature dependent in cells infected with temperature-sensitive mutants. The good correlation between its phosphorylation and morphological transformation, together with its relative abundance among phosphorylated proteins and its subcellular localization, suggests that phosphorylation of the 130-kDa glycoprotein is one of the primary events important for cell transformation by p60v-src and related oncogene products.
Hamaguchi
M
M
Rockefeller University, New York, New York 10021.
Matsuda
M
M
Hanafusa
H
H
D000818:Animals; D001358:Avian Sarcoma Viruses / Q000201:enzymology / Q000235:genetics*; D002462:Cell Membrane / Q000378:metabolism; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002642:Chick Embryo; D005347:Fibroblasts / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D009154:Mutation; D015688:Oncogene Protein pp60(v-src) / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification; D010449:Peptide Mapping; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D013379:Substrate Specificity
D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)