Altered kinase C function in transformed BALB/c3T3 cells.
Comparative studies of kinase C function were performed in an untransformed (A31) and the benzo[a]pyrene (BPA31), dimethylbenz[a]anthracene (DA31), and Kirsten sarcoma virus (KA31) transformed BALB/c 3T3 mouse fibroblast cell lines. The 80-kDa kinase C dependent phosphoprotein (pp80), an in vivo marker of kinase C activity, was markedly decreased in the transformed cells although the amount of the 80-kDa substrate protein in the BPA31 cells was similar to that in the untransformed A31 cells. Total cell lysate kinase C levels were lower in the transformed cells but this difference could not account for the reduced pp80 phosphorylation. Increased affinity of kinase C for the membrane fraction in the BPA31 cells may account for decreased phosphorylation of pp80.
Yang
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Division of Medical Oncology, Harbor-UCLA Medical Center, Torrance 90509.
D000818:Animals; D002461:Cell Line, Transformed; D005347:Fibroblasts / Q000378:metabolism / Q000503:physiopathology*; D007118:Immunoassay; D051379:Mice; D008807:Mice, Inbred BALB C; D008938:Mitosis / Q000187:drug effects; D009363:Neoplasm Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism / Q000502:physiology*; D013574:Synaptosomes / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000503:physiopathology
D009363:Neoplasm Proteins; D010750:Phosphoproteins; C036987:protein p80; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate