title: Indication of a protein kinase C-independent pathway for NADPH oxidase activation in human neutrophils.
abstract: A potent tyrosine phosphatase inhibitor, pervanadate, induced (i) translocation of the cytosolic NADPH oxidase factors, p47-phox and p67-phox, to the plasma membrane; and (ii) O2- production in human neutrophils. However, the translocation of p47-phox and p67-phox was inhibited by H-7, a protein kinase C (PKC) inhibitor without markedly affecting O2- production in whole neutrophils. Results from the plasma membrane fraction showed that NADPH oxidase activity in neutrophils treated with pervanadate did not vary in the presence or absence of H-7, despite a lower content of p47-phox and p67-phox in H-7-treated neutrophils. These findings suggest that in addition to the well-known PKC-dependent pathway, there may exist another PKC-independent pathway to activate NADPH oxidase in human neutrophils. This pathway involves protein tyrosine phosphorylation but does not seem to necessitate translocation of p47-phox and p67-phox to the plasma membrane.
authors.affiliation: Department of Environmental Biochemistry, Kyoto Pharmaceutical University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kawakami
authors.forename: H
authors.initials: H
authors.lastname: Takemasa
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: S
authors.initials: S
authors.lastname: Shimohama
authors.forename: S
authors.initials: S
authors.lastname: Fujimoto
mesh_terms: D004789:Enzyme Activation; D006801:Humans; D019255:NADPH Oxidases / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology*; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D019255:NADPH Oxidases; D011493:Protein Kinase C