A Novel Cytosolic Component, p40 phox, of Respiratory Burst Oxidase Associates with p67 phox and Is Absent in Patients with Chronic Granulomatous Disease Who Lack p67 phox

Abstract

Cytosolic components of human neutrophils, p47 phox and p67 phox , deficiencies of which lead to chronic granulomatous disease (CGD), potentiate respiratory burst oxidase translocating from cytosol to membrane upon cell stimulation. In this report we describe a novel cytosolic component, p40 phox , which consistently behaves with p67 phox through immunoprecipitation and column works, and is missing in patients with CGD who lack p67 phox . Although actin has been reported to be involved in O 2 − generation, the p40 phox profile did not correspond to that of actin. The tight association between p40 phox and p67 phox was not affected by treatment with a mixture of deoxycholate and Nonidet P-40, until subjected to SDS-PAGE. Addition of recombinant p67 phox to cytosol did not produce any additional p40 phox in the immunoprecipitate, unlike the additive increment in the band of p67 phox . These results suggest that p40 phox forms a complex with p67 phox in a molar ratio of 1:1, without any free p40 phox in the cytosol.