Vasoactive intestinal peptide (VIP) activation of nuclear protein kinase C in purified nuclei of rat splenocytes.
We have examined the actions of vasoactive intestinal peptide (VIP) and certain other known immune modulators on a nuclear pool(s) of protein kinase C (PKC) in isolated rat splenocyte nuclei. Rat splenocyte nuclei pure by enzymatic and electron microscope criteria demonstrated a time- and concentration-dependent activation of nuclear PKC (nPKC) by VIP. A biphasic pattern of three bell-shaped curves was observed with peak phosphorylation at 10(-15), 10(-9) and 10(-6)M VIP. The phosphorylation of endogenous nuclear substrates was characterized as a PKC-mediated event by use of three known PKC inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), sphingosine, and staurosporine, which produced similar phosphate incorporation measurements. Also, this activity was blocked with the addition of a monoclonal antibody to PKC. Inhibitors of the ability of VIP to activate nPKC included somatostatin, 8-bromo-cAMP, peripheral benzodiazepine receptor modulators, and the PKC inhibitors, sphingosine and staurosporine. These data have direct relevance to our knowledge of cell-mediated immunity.
Zorn
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Department of Pharmacology and Therapeutics, University of South Florida College of Medicine, Tampa 33612.
Russell
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D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D001570:Benzodiazepinones / Q000494:pharmacology; D002467:Cell Nucleus / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000494:pharmacology; D013110:Sphingosine / Q000494:pharmacology; D013154:Spleen / Q000378:metabolism / Q000648:ultrastructure; D019311:Staurosporine; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D000470:Alkaloids; D001570:Benzodiazepinones; D007546:Isoquinolines; D009687:Nuclear Proteins; D010750:Phosphoproteins; D015124:8-Bromo Cyclic Adenosine Monophosphate; C028513:4'-chlorodiazepam; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D007334:Insulin-Like Growth Factor I; D011493:Protein Kinase C; D019311:Staurosporine; D013110:Sphingosine; C037850:PK 11195