Combination of arachidonic acid and guanosine 5'-O-(3-thiotriphosphate) induce translocation of rac p21s to membrane and activation of NADPH oxidase in a cell-free system.
The superoxide-generating NADPH oxidase system in phagocytes consists of membrane-associated cytochrome b558 and three cytosolic components named p67-phox, p47-phox, and rac p21s. In a cell-free system consisting of membrane and cytosol, the oxidase can be activated with guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and an unsaturated fatty acid such as arachidonic acid (AA). Incubation of cytosol and membrane with AA alone caused clear translocation of p47-phox and p67-phox to the membrane, but only slight translocation of rac p21s. GTP gamma S alone did not significantly induce the translocation of rac p21s. However, GTP gamma S in combination with AA markedly augmented rac p21s translocation to the membrane. The translocation of rac p21s is not induced by GDP or GDP beta S. These results indicate that the GTP-bound active form of rac p21s is the entity that is translocated to the membrane by the action of AA.
Department of Biochemistry, Tsukuba Research Laboratories, Eisai Co. Ltd., Ibaraki, Japan.
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T
Sawai
M
M
Asada
H
H
Nunoi
I
I
Matsuda
S
S
Ando
T
T
Sasaki
K
K
Kaibuchi
Y
Y
Takai
K
K
Katayama
D000595:Amino Acid Sequence; D016718:Arachidonic Acid / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002474:Cell-Free System; D003600:Cytosol / Q000378:metabolism; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000032:analysis / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019255:NADPH Oxidases; D009842:Oligopeptides / Q000138:chemical synthesis / Q000276:immunology; D010750:Phosphoproteins / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D013873:Thionucleotides / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D020744:rac GTP-Binding Proteins
D009842:Oligopeptides; D010750:Phosphoproteins; D013873:Thionucleotides; C079789:neutrophil cytosol factor 67K; D013481:Superoxides; D006153:Guanosine Diphosphate; D016718:Arachidonic Acid; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D009252:NADPH Dehydrogenase; D019204:GTP-Binding Proteins; D020744:rac GTP-Binding Proteins