Analysis of middle tumor antigen and pp60c-src interactions in polyomavirus-transformed rat cells.
The relative abundance of pp60c-src molecules associated with polyomavirus (Py) middle tumor antigen (MTAg) and the relative abundance of MTAg associated with pp60c-src in a variety of Py-transformed rat cells was determined by quantitative immunoblot analyses which detect pp60c-src or Py MTAg. The results demonstrate that approximately 5 to 10% of the total immunoprecipitable pp60c-src molecules in Py-transformed rat cells are stably associated with MTAg and have elevated protein kinase activities. In these same cells, it was found that approximately 10 to 15% of the detectable MTAg molecules are stably associated with pp60c-src. Other results presented in this report demonstrate that approximately 50 to 75% of the total MTAg-associated cellular tyrosine kinase activity potentially represents the enzymatic activity of pp60c-src, while the remaining 25 to 50% represents the activity of other cellular tyrosine kinases. Our results also show that most pp60c-src molecules associated with Py MTAg do not possess electrophoretic mobilities that are altered from those of pp60c-src molecules not associated with MTAg or pp60c-src molecules obtained from normal rodent cells.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000957:Antigens, Viral, Tumor / Q000032:analysis*; D002460:Cell Line; D002472:Cell Transformation, Viral; D007118:Immunoassay; D011120:Polyomavirus / Q000032:analysis* / Q000201:enzymology / Q000276:immunology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D016392:Proto-Oncogene Proteins pp60(c-src); D051381:Rats; D014764:Viral Proteins / Q000032:analysis*
D000911:Antibodies, Monoclonal; D000957:Antigens, Viral, Tumor; D011518:Proto-Oncogene Proteins; D014764:Viral Proteins; D011505:Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src)