title: Protein kinase activity associated with simian virus 40 T antigen.
abstract: Incubation of simian virus 40 (SV40) tumor (T) antigen-containing immunoprecipitates with [gamma-32P]ATP results in the incorporation of radioactive phosphate into large T antigen. Highly purified preparations of large T antigen from a SV40-transformed cell line, SV80, are able to catalyze the phosphorylation of a known phosphate acceptor, casein. The kinase activity migrates with large T antigen through multiple purification steps. Sedimentation analysis under non-T-antigen-aggregating conditions reveals that kinase activity and the immunoreactive protein comigrate as a 6S structure. The kinase activity of purified preparations of large T antigen can be specifically adsorbed to solid-phase anti-T IgG, and partially purified T antigen from a SV40 tsA transformation is thermolabile in its ability to phosphorylate casein when compared to comparably purified wild-type T antigen. These observations indicate that the SV40 large T antigen is closely associated with protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) activity.
mesh_terms: D000956:Antigens, Viral; D002460:Cell Line; D002472:Cell Transformation, Viral; D006801:Humans; D008970:Molecular Weight; D010766:Phosphorylation; D011233:Precipitin Tests; D011494:Protein Kinases / Q000032:analysis*; D013539:Simian virus 40 / Q000201:enzymology* / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D011494:Protein Kinases