Immunochemical evidence that three protein kinase C isozymes increase in abundance during HL-60 differentiation induced by dimethyl sulfoxide and retinoic acid.
Activity of the Ca2+/phospholipid-dependent protein kinase C has been shown to increase during differentiation of the human promyelocytic leukemia cell line HL-60 by dimethyl sulfoxide and retinoic acid (Zylber-Katz, E., and Glazer, R. I. (1985) Cancer Res. 45, 5159-5164). Antipeptide antibodies were prepared that specifically recognize the alpha, beta, and gamma isozymes of protein kinase C in rat brain cytosol and HL-60 cell extracts. The three isozymes do not share a common tissue distribution pattern. The gamma enzyme is abundant in brain but a relatively minor component in HL-60 cells; the opposite is true for the alpha enzyme. All three isozymes increase at least 2-fold in abundance in HL-60 cells exposed to 1.2% dimethyl sulfoxide for 48 h. The increase in abundance of the alpha and beta isoforms reaches 7- and 5-fold, respectively, by 96 h without further increase in the abundance of the gamma isozyme. Similarly, all three isozymes increase at least 1.5-fold in abundance after 48 h and 3-fold after 96 h with 1 microM retinoic acid. No further increase in the abundance of any of the isozymes is seen between 96 and 144 h of incubation with retinoic acid. The increase in protein kinase C activity is not limited to the cytosolic forms of the enzyme; a parallel increase in membrane-associated protein kinase C is also observed during differentiation. Approximately 10% of total protein kinase C activity is membrane-associated in both control and differentiating cells. These studies provide the first immunochemical evidence that all three protein kinase C isozymes increase during HL-60 cell differentiation, and they suggest that the increase in the isozyme levels may be coordinately regulated.
Program in Molecular Biology, Memorial Sloan-Kettering Cancer Research Center, New York, New York 10021.
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Makowske
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Ballester
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Rosen
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D003600:Cytosol / Q000201:enzymology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D007951:Leukemia, Myeloid / Q000201:enzymology*; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014018:Tissue Distribution; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D007527:Isoenzymes; D014212:Tretinoin; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D004121:Dimethyl Sulfoxide