Enhancement of cellular src gene product associated tyrosyl kinase activity following polyoma virus infection and transformation.
We examine the interaction between polyoma-virus-encoded middle tumor antigen and the cellular src gene product, pp60c-src, using a series of monoclonal antibodies that recognize mammalian pp60c-src. Our results show that infection of mouse cells with transformation-competent strains of polyoma virus results in the stimulation of pp60c-src kinase activity severalfold over that observed in uninfected mouse cells and mouse cells infected with transformation-deficient polyoma virus. A similar degree of enhancement of pp60c-src kinase activity was found in polyoma-virus-transformed rodent cells. No differences were detected in the level of pp60c-src synthesis in polyoma-virus-infected and uninfected mouse cells or polyoma-virus-transformed and normal rodent cells. These studies demonstrate that polyoma-virus-encoded middle tumor antigen is associated with pp60c-src in lysates of polyoma-virus-infected and polyoma-virus-transformed cells and suggest a novel mechanism for the functional activation of a cellular proto-oncogene product, namely, that the interaction between middle tumor antigen and pp60c-src leads to a stimulation of pp60c-src tyrosyl kinase activity.
D000818:Animals; D000911:Antibodies, Monoclonal; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D005796:Genes; D005814:Genes, Viral; D051379:Mice; D015688:Oncogene Protein pp60(v-src); D010766:Phosphorylation; D011120:Polyomavirus / Q000201:enzymology / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics* / Q000302:isolation & purification; D011505:Protein-Tyrosine Kinases; D014764:Viral Proteins / Q000235:genetics* / Q000302:isolation & purification
D000911:Antibodies, Monoclonal; D014764:Viral Proteins; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D015688:Oncogene Protein pp60(v-src)