NCF4, SH3PXD4, Neutrophil cytosol factor 4, NCF-4, Neutrophil NADPH oxidase factor 4, SH3 and PX domain-containing protein 4, p40-phox, p40phox
The protein encoded by this gene is a cytosolic regulatory component of the superoxide-producing phagocyte NADPH-oxidase, a multicomponent enzyme system important for host defense. This protein is preferentially expressed in cells of myeloid lineage. It interacts primarily with neutrophil cytosolic factor 2 (NCF2/p67-phox) to form a complex with neutrophil cytosolic factor 1 (NCF1/p47-phox), which further interacts with the small G protein RAC1 and translocates to the membrane upon cell stimulation. This complex then activates flavocytochrome b, the membrane-integrated catalytic core of the enzyme system. The PX domain of this protein can bind phospholipid products of the PI(3) kinase, which suggests its role in PI(3) kinase-mediated signaling events. The phosphorylation of this protein was found to negatively regulate the enzyme activity. Alternatively spliced transcript variants encoding dfunction:Component of the NADPH-oxidase, a multicomponent enzyme system responsible for the oxidative burst in which electrons are transported from NADPH to molecular oxygen, generating reactive oxidant intermediates. It may be important for the assembly and/or activation of the NADPH-oxidase complex.,similarity:Contains 1 PX (phox homology) domain.,similarity:Contains 1 SH3 domain.,subunit:p40-PHOX associates primarily with p67-PHOX to form a complex with p47-PHOX.,tissue specificity:Expression is restricted to hematopoietic cells.,
