Cell-Free Activation of the Respiratory Burst Oxidase by Protein Kinase C

• Published in: Blood cells, molecules, & diseases Vol. 21; no. 3; pp. 201 - 206
• Main Authors: El Benna, Jamel, Park, Jeen-Woo, Ruedi, Julie M., Babior, Bernard M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 1995; Elsevier Science Ltd
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Adenosine Triphosphate - metabolism; Animals; Catalase - pharmacology; Cattle; Cell-Free System; Cytosol - enzymology; Enzyme Activation - drug effects; Enzyme Inhibitors - pharmacology; Guanosine 5'-O-(3-Thiotriphosphate) - pharmacology; Indoles - pharmacology; Isoquinolines - pharmacology; Maleimides - pharmacology; NADH, NADPH Oxidoreductases - metabolism; NADP - metabolism; NADPH Oxidases; Nerve Tissue Proteins - antagonists & inhibitors; Nerve Tissue Proteins - metabolism; Nerve Tissue Proteins - pharmacology; Phosphoproteins - metabolism; Phosphorylation - drug effects; Piperazines - pharmacology; Protein Kinase C - antagonists & inhibitors; Protein Kinase C - metabolism; Protein Kinase C - pharmacology; Protein Processing, Post-Translational - drug effects; Rats; Respiratory Burst - drug effects; Superoxide Dismutase - pharmacology
• ISSN: 1079-9796; 1096-0961
• DOI: 10.1006/bcmd.1995.0023

In intact neutrophils, phorbol ester treatment activates the respiratory burst oxidase, the enzyme responsible for O 2-production by phagocytes. This effect is thought to be dependent on protein kinase C and on the phosphorylation of p47 phox . In this paper, we report that protein kinase C activates the respiratory burst oxidase in a cell-free system consisting of isolated neutrophil cytosol and membrane. Oxidase activation required a highly active protein kinase C, recombinant p47 phox and ATP, and was inhibited by the protein kinase C inhibitors H-7 and GF-109203X. Partial depletion of cytosolic ATP by dialysis reduced oxidase activation by over 50%. In contrast, neither protein kinase C inhibitors nor ATP depletion affected oxidase activation by SDS. These findings strongly suggest that in the cell-free system, the oxidase can be activated by the phosphorylation of p47 phox .