title: Serine/threonine-specific protein kinase activity associated with viral pp60src protein.
abstract: Three different types of experiments are presented in this paper, the results of which converge to indicate that the viral src protein associates with and modulates the activity and/or the specificity of a serine/threonine protein kinase. Firstly, a 60-kDa protein from extracts of FR3T3 rat fibroblasts transformed by wild-type Rous sarcoma virus (SRD-FR3T3) is shown to be immunoprecipitated with a monoclonal antibody (mAb) raised against bacterially produced pp60v-src, the mAb327 [Lipsich, L. A., Lewis, A. J. & Brugge, J. S. (1983) J. Virol. 48, 352-360] and to be phosphorylated in vitro at serine/threonine/tyrosine residues, in the ratio 25:53:22. Under the same experimental conditions, the pp60c-src protein immunoprecipitated with mAb327 from extracts of NIH c-src overexpresser cells is phosphorylated exclusively on tyrosine residues. Secondly, the results of immunoprecipitation experiments using a tumor-bearing rabbit (TBR) serum and reported in an earlier work [David-Pfeuty, T. & Hovanessian, A. (1984) Eur. J. Biochem. 140, 325-342], together with those reported here, suggest that the TBR-immunoprecipitated pp60v-src coprecipitates with a cellular protein related to the 60-kDa subunit of the Ca2+/calmodulin protein kinase II from brain. Finally, partially purified preparations of pp60v-src, but not of pp60c-src, are shown to contain a Ca2+/calmodulin-dependent protein kinase activity that phosphorylates a 52-kDa protein substrate.
authors.affiliation: Institut Curie-Biologie, Centre Universitaire, Orsay, France.
authors.forename: T
authors.initials: T
authors.lastname: David-Pfeuty
authors.forename: Y
authors.initials: Y
authors.lastname: Nouvian-Dooghe
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001921:Brain / Q000201:enzymology; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002642:Chick Embryo; D009206:Myocardium / Q000201:enzymology; D015688:Oncogene Protein pp60(v-src) / Q000378:metabolism*; D010449:Peptide Mapping; D010766:Phosphorylation; D011233:Precipitin Tests / Q000379:methods; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D051381:Rats; D013379:Substrate Specificity; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D014764:Viral Proteins; D011494:Protein Kinases; D015688:Oncogene Protein pp60(v-src); D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases