de Mendez I, Adams A G, Sokolic R A, Malech H L, Leto T L
Laboratory of Host Defenses, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892, USA.
EMBO J. 1996 Mar 15;15(6):1211-20.
Src homology 3 (SH3) domains mediate specific protein-protein interactions crucial for signal transduction and protein subcellular localization. Upon phagocyte stimulation, two SH3 domain-containing cytosolic components of the NADPH oxidase, p47phox and p67phox, are recruited to the membrane where they interact with flavocytochrome b558 to form an activated microbicidal oxidase. Deletion analysis of p47phox and p67phox in transfected K562 cells demonstrated multiple SH3-mediated interactions between p47phox and the transmembrane flavocytochrome b558 and also between the cytosolic components themselves. The core region of p47phox (residues 151-284), spanning both SH3 domains, was required for flavocytochrome-dependent translocation and oxidase activity in whole cells. Furthermore, translocation of p67phox occurred through interactions of its N-terminal domain (residues 1-246) with p47phox SH3 domains. Both of these interactions were promoted by PMA activation of cells and were influenced by the presence of other domains in both cytosolic factors. Deletion analysis also revealed a third SH3 domain-mediated interaction involving the C-termini of both cytosolic factors, which also promoted p67phox membrane translocation. These data provide evidence for a central role for p47phox in regulation of oxidase assembly through several SH3 domain interactions.
Src同源结构域3（SH3）介导特定的蛋白质-蛋白质相互作用，这对于信号转导和蛋白质亚细胞定位至关重要。在吞噬细胞受到刺激时，烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶的两个含SH3结构域的胞质成分，即p47phox和p67phox，会被招募到细胞膜，在那里它们与黄素细胞色素b558相互作用，形成一种活化的杀菌氧化酶。对转染的K562细胞中的p47phox和p67phox进行缺失分析表明，p47phox与跨膜黄素细胞色素b558之间以及胞质成分自身之间存在多种由SH3介导的相互作用。p47phox的核心区域（第151 - 284位氨基酸残基），跨越两个SH3结构域，是全细胞中黄素细胞色素依赖性易位和氧化酶活性所必需的。此外，p67phox的易位是通过其N端结构域（第1 - 246位氨基酸残基）与p47phox的SH3结构域相互作用发生的。这两种相互作用都由细胞的佛波酯（PMA）激活所促进，并且受到这两种胞质因子中其他结构域的存在的影响。缺失分析还揭示了涉及这两种胞质因子C末端的第三种由SH3结构域介导的相互作用，这种相互作用也促进了p67phox向膜的易位。这些数据为p47phox通过几种SH3结构域相互作用在氧化酶组装调节中发挥核心作用提供了证据。
