title: Tyrosine phosphorylation of a 22-kDa protein is correlated with transformation by Rous sarcoma virus.
abstract: Recent studies from this laboratory have identified novel cytoskeletal proteins that are phosphorylated on tyrosine in vivo in Rous sarcoma virus-transformed chick fibroblasts (Glenney, J. R., Jr., and Zokas, L. (1989) J. Cell Biol. 108, 2401-2408). In the present report, the phosphorylation of these proteins was examined in cells expressing the nonmyristylated mutants of src that are not transformed. A good correlation was found between transformation and the tyrosine phosphorylation of a 22-kDa protein. Tyrosine phosphorylation of the 22-kDa protein was reduced more than 95% in cells expressing the nonmyristylated mutants of src. Size fractionation revealed that the 22-kDa phosphoprotein in transformed chick fibroblasts is found in a Mr 150,000 complex. Monoclonal antibodies were used to screen various chicken tissues where the 22-kDa protein was found at high levels in muscle and lung with low levels in epithelial cells and brain. The 22-kDa protein becomes an excellent candidate for a mediator of transformation by the tyrosine kinase class of oncogenes.
authors: Lucille P. Markey Cancer Center, Department of Biochemistry, University of Kentucky College of Medicine, Lexington 40536-0093.
authors: J R
authors: JR
authors: Glenney
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002471:Cell Transformation, Neoplastic; D002642:Chick Embryo; D005347:Fibroblasts / Q000378:metabolism; D008970:Molecular Weight; D009154:Mutation; D019814:Myristic Acid; D009227:Myristic Acids / Q000032:analysis; D010750:Phosphoproteins / Q000302:isolation & purification; D010766:Phosphorylation; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000032:analysis; D011518:Proto-Oncogene Proteins / Q000032:analysis; D016392:Proto-Oncogene Proteins pp60(c-src); D014443:Tyrosine / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D009227:Myristic Acids; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D019814:Myristic Acid; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)