Protein kinase C increases the activity of the polyoma virus middle T antigen-associated phosphatidylinositol kinase.
Exposure of polyoma virus-transformed fibroblasts to the protein kinase C-stimulating phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) is known to increase the transforming potential of the virus's middle T antigen. Here it is shown that this TPA treatment also stimulates an 85 kDa phosphatidylinositol kinase associated with the middle T antigen. Since activation of this kinase is known to be necessary, although not by itself sufficient for the transformation of cells by polyoma virus, bursts of protein kinase C activity, triggered by TPA or various cellular receptors, might enhance the oncogenicity of polyoma virus by stimulating this middle T antigen-associated phosphatidylinositol kinase.
Raptis
L
L
Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada.
Bell
J
J
Whitfield
J F
JF
D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism*; D002461:Cell Line, Transformed; D004789:Enzyme Activation; D007700:Kinetics; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000952:Antigens, Polyomavirus Transforming; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate