title: Evidence that a phosphotyrosine-containing 120,000 Da protein from Rous sarcoma virus-infected cells is phosphorylated by pp60v-src.
abstract: Phosphorylation of a phosphotyrosine-containing 120,000 Da protein (pp120) in Rous sarcoma virus (RSV)-infected mammalian cells and in in vitro protein kinase reactions was examined. Phosphorylated pp120 was co-immunoprecipitated with anti-pp60v-src antibodies only from RSV-transformed or revertant vole fibroblasts which contained active pp60v-src tyrosine kinase activity or from temperature-sensitive RSV-infected vole cells grown at the permissive temperature. Pp120 was phosphorylated on tyrosine in in vitro immune complex kinase reactions containing both pp120 and enzymatically active pp60v-src. Inhibition of pp60v-src's kinase activity blocked phosphorylation of pp120 in vitro. These results support the proposal that pp120 tyrosine phosphorylation is pp60v-src-dependent and that pp120 may thus serve as a substrate of pp60v-src in RSV-transformed mammalian cells.
authors: Basic Science Program, University of Hawaii, Honolulu 96813.
authors: A F
authors: AF
authors: Lau
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002999:Clone Cells; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D015688:Oncogene Protein pp60(v-src); D010449:Peptide Mapping; D010750:Phosphoproteins / Q000096:biosynthesis*; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012191:Retroviridae Proteins / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D010750:Phosphoproteins; D012191:Retroviridae Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)