Pharmacological evidence for system-dependent involvement of protein kinase C isoenzymes in phorbol ester-suppressed gap junctional communication.
Several phorbol esters are potent activators of protein kinase C. They down-regulate gap junctional intercellular communication and induce phosphorylation of connexin43, but the sensitivity and extent of responses vary much between systems. We asked whether the total protein kinase C enzyme activity or the protein kinase C isoenzyme constitution was of importance for such variations. Some fibroblastic culture systems were compared. It was concluded that the total protein kinase C enzyme activity did not determine the sensitivity to phorbol esters. Furthermore, the use of isotype-specific inhibitors of protein kinase C indicated that protein kinase C alpha, delta, and epsilon may be involved to different extents in different fibroblastic systems in the response to phorbol esters.
Cruciani
V
V
Department of Environmental and Occupational Cancer, Institute for Cancer Research, The Norwegian Radium Hospital, N-0310 Oslo, Norway.
Husøy
T
T
Mikalsen
S O
SO
D002227:Carbazoles / Q000494:pharmacology; D002450:Cell Communication / Q000187:drug effects; D002478:Cells, Cultured; D018031:Connexin 43 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D017629:Gap Junctions / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D002227:Carbazoles; D018031:Connexin 43; D007211:Indoles; D007527:Isoenzymes; D008301:Maleimides; C081021:Go 6976; C089212:protein kinase D; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon; C070515:bisindolylmaleimide I; D013755:Tetradecanoylphorbol Acetate