Phorbol ester-induced activation of protein kinase C leads to increased formation of diacylglycerol in human neutrophils.
Human neutrophils stimulated with a phorbol ester (phorbol 12-myristrate 13-acetate or phorbol 12,13-dibutyrate) responded with an increase in diacylglycerol, considered the natural activator of protein kinase C. The amounts of diacylglycerol formed were considerable, reaching 700-900% of basal after 20 min. In contrast, 4-alpha-phorbol 12-myristate 13-acetate did not induce any detectable formation of diacylglycerol. Simultaneously, phorbol 12-myristate 13-acetate exposure caused increased breakdown of both phosphatidylcholine and phosphatidylinositol 4,5-bisphosphate. These results suggest that once activated, protein kinase C can positively modulate its own activity by inducing additional formation of diacylglycerol from at least two different sources.
Fällman
M
M
Department of Cell Biology, University of Linköping, Sweden.
Stendahl
O
O
Andersson
T
T
D002118:Calcium / Q000378:metabolism; D004075:Diglycerides / Q000096:biosynthesis*; D004789:Enzyme Activation; D005989:Glycerides / Q000096:biosynthesis*; D006801:Humans; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology*; D010713:Phosphatidylcholines / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
C011439:1,2-diacylglycerol; D004075:Diglycerides; D005989:Glycerides; D010713:Phosphatidylcholines; D010716:Phosphatidylinositols; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium