Verhoeven, A.J., Leusen, J.H., Kessels, G.C., Hilarius, P.M., de Bont, D.B. and Liskamp, R.M.J. (1993) Inhibition of neutrophil NADPH oxidase assembly by a myristoylated pseudosubstrate of protein kinase C. Journal of Biological Chemistry, 268(25), pp. 18593-8.
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Publisher's URL: http://www.jbc.org/content/268/25/18593.abstract
Abstract
To further define the role played by protein kinase C (PKC) in the activation of the neutrophil NADPH oxidase, we have utilized a pseudosubstrate of PKC which was myristoylated at the N terminus. In electropermeabilized neutrophils, the myristoylated pseudosubstrate Phe-Ala-Arg-Lys-Gly-Ala-Leu-Arg-Gln (myr-psi PKC) inhibited PMA-induced protein phosphorylations and activation of the NADPH oxidase, induced either by PMA or by the receptor agonist formyl-methionyl-leucyl-phenylalanine. Both the pseudosubstrate lacking the N-terminal myristate (psi PKC) and a myristoylated control peptide (Phe-Ala-Glu-Asp-Gly-Ala-Leu-Glu-Gln, myr-CP) were without effect on these responses. The myristoylated pseudosubstrate was also tested in a cell-free system, in which NADPH oxidase activation can be achieved by addition of SDS and guanosine 5'-3-O-(thio)triphosphate in a staurosporine-insensitive manner. Myr-psi PKC, but not psi PKC or myr-CP, proved to be a potent inhibitor of NADPH oxidase activity in the cell-free system, indicating that the inhibition observed in permeabilized neutrophils may have been caused by an effect other than PKC inhibition. In the presence of myr-psi PKC, translocation in the cell-free system of the cytosolic oxidase components p47-phox and p67-phox to the plasma membrane was inhibited. From these results we conclude that myristoylation profoundly increases the ability of pseudosubstrates of PKC to inhibit not only PKC-mediated phosphorylations, but also NADPH oxidase activation. The latter effect, however, is most probably not related to PKC inhibition but may indicate a critical role of the membrane surface charge in the translocation of the cytosolic oxidase components p47-phox and p67-phox.
Item Type: | Articles |
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Status: | Published |
Refereed: | Yes |
Glasgow Author(s) Enlighten ID: | Liskamp, Professor Robert |
Authors: | Verhoeven, A.J., Leusen, J.H., Kessels, G.C., Hilarius, P.M., de Bont, D.B., and Liskamp, R.M.J. |
College/School: | College of Science and Engineering > School of Chemistry |
Journal Name: | Journal of Biological Chemistry |
Publisher: | American Society for Biochemistry and Molecular Biology, Inc. |
ISSN: | 0021-9258 |
ISSN (Online): | 1083-351X |
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