Translocation of Rac Correlates with NADPH Oxidase Activation EVIDENCE FOR EQUIMOLAR TRANSLOCATION OF OXIDASE COMPONENTS

摘要: Activation of the superoxide-generating NADPH oxidase system human neutrophils involves assembly several neutrophil components, some located on plasma membrane and others in cytosol. It has recently been established that one required components for activity is GTP-binding protein Rac. To further investigate role Rac system, studies were carried out to determine its subcellular distribution resting activated neutrophils. In cells, an associated guanine nucleotide regulatory factor, GDP dissociation inhibitor (GDI), only cytosol, along with other known factors, p47-phox p67-phox. After activation phorbol 12-myristate 13-acetate or formyl-methionyl-leucyl-phenylalanine, was translocated from cytosol membrane, this translocation corresponded temporally p67-phox generation superoxide. GDI remained localized suggesting involved Rac-GDI complex prior translocation. Determination quantities cytosolic factors indicated Rac, p47-phox, are simultaneously equimolar amounts, but membrane-associated cytochrome b present at 3-4-fold molar excess. These findings suggest may play a active complex.