Resolution of major protein kinase substrates in neutrophil cytosol in response to DAG/PS and arachidonic acid stimulation and the selective action of various protein kinase inhibitors.
Stimulation of human neutrophils induces phosphorylation of several cellular proteins. Human neutrophils possess calcium-dependent protein kinase C (PKC) alpha and beta isoforms and calcium-independent n isoforms. Little is known, however, of the physiological substrates of each isoform. In this study, we characterized the substrates of calcium-dependent and -independent PKC isoforms and the substrate of PKC activated by arachidonic acid. Furthermore, we found that the PKC inhibitor H-7 failed to inhibit phosphorylation of endogenous substrates of calcium-independent PKC activity. These results may help to understand the role of PKC in neutrophil activation and shed light on the different responses elicited by H-7 in intact cells.
el Benna
J
J
INSERM U.294, Service d'Hématologie et d'Immunologie Biologiques, CHU Xavier Bichat, Paris, France.
Labro
M T
MT
Hakim
J
J
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D001095:Arachidonic Acids / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D004075:Diglycerides / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D008970:Molecular Weight; D009504:Neutrophils / Q000201:enzymology*; D010718:Phosphatidylserines / Q000494:pharmacology*; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D001095:Arachidonic Acids; D004075:Diglycerides; D007546:Isoquinolines; D010718:Phosphatidylserines; D010879:Piperazines; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium