Wientjes F B, Hsuan J J, Totty N F, Segal A W
Division of Molecular Medicine, University College, London, U.K.
Biochem J. 1993 Dec 15;296 ( Pt 3)(Pt 3):557-61. doi: 10.1042/bj2960557.
The NADPH oxidase generates superoxide in phagocytic cells. It is important for immunity and its deficiency leads to chronic granulomatous disease (CGD). It consists of a membrane-bound flavocytochrome b that lies dormant until activated by the translocation to the plasma membrane of cytosolic proteins, p47phox (phox for phagocyte oxidase), p67phox and p21rac, a small GTP-binding protein. We show here that a novel component, p40phox, forms an activation complex with p47phox and p67phox with which it translocates to the membrane to associate with the flavocytochrome b. cDNA cloning and amino acid analysis revealed that p40phox has an src homology 3 (SH3) domain and a large region of sequence similarity with the N-terminus of p47phox. The primary association of p40phox appears to be with p67phox, and it is present in reduced amounts in patients with CGD lacking p67phox.
NADPH氧化酶在吞噬细胞中产生超氧化物。它对免疫很重要，其缺陷会导致慢性肉芽肿病（CGD）。它由一种膜结合的黄素细胞色素b组成，该黄素细胞色素b处于休眠状态，直到被胞质蛋白p47phox（吞噬细胞氧化酶的phox）、p67phox和小GTP结合蛋白p21rac转运到质膜而被激活。我们在此表明，一种新成分p40phox与p47phox和p67phox形成激活复合物，并与之一起转运到膜上，与黄素细胞色素b结合。cDNA克隆和氨基酸分析显示，p40phox具有一个src同源3（SH3）结构域，并且在序列上与p47phox的N端有很大的相似区域。p40phox的主要结合对象似乎是p67phox，在缺乏p67phox的CGD患者中其含量减少。
