A POINT MUTATION IN GP91-PHOX OF CYTOCHROME B(558) OF THE HUMAN NADPH OXIDASE LEADING TO DEFECTIVE TRANSLOCATION OF THE CYTOSOLIC PROTEINS P47-PHOX AND P67-PHOX
A POINT MUTATION IN GP91-PHOX OF CYTOCHROME B(558) OF THE HUMAN NADPH OXIDASE LEADING TO DEFECTIVE TRANSLOCATION OF THE CYTOSOLIC PROTEINS P47-PHOX AND P67-PHOX
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DOI：
10.1172/jci117207
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发表时间：
1994-05-01
影响因子：
15.9
通讯作者：
VERHOEVEN, AJ
中科院分区：
文献类型：
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作者：
LEUSEN, JHW;DEBOER, M;VERHOEVEN, AJ
人吞噬细胞的超氧化物形成NADPH氧化酶由膜结合蛋白和胞质蛋白组成，在细胞活化时，其在质膜上组装以形成活性酶。慢性肉芽肿病（CGD）患者存在以下组分之一缺陷：p47-phox和p67-phox，存在于静息吞噬细胞的胞质溶胶中; gp 91-phox和p22-phox，构成膜结合细胞色素B（558）。在一个X连锁CGD患者中，我们发现了一个新的错义突变，预测在gp 91-phox的残基500处的Asp -> Gly取代，与患者中性粒细胞中正常量的无功能细胞色素B（558）相关。在PMA刺激的中性粒细胞和中性粒细胞膜和胞浆中的无细胞易位试验中，胞浆蛋白p47-phox和p67-phox与患者的膜部分的关联受到强烈干扰。此外，在无细胞测定中，gp 91-phox的合成肽模拟结构域491-504抑制NADPH氧化酶活性（IC 50约10 μ M），并且在无细胞易位测定中抑制p47-phox和p67-phox的易位。我们的结论是，残基500的gp 91-phox驻留在一个区域的p47-phox和p67-phox的稳定结合的关键。
The superoxide-forming NADPH oxidase of human phagocytes is composed of membrane-bound and cytosolic proteins which, upon cell activation, assemble on the plasma membrane to form the active enzyme. Patients suffering from chronic granulomatous disease (CGD) are defective in one of the following components: p47-phox and p67-phox, residing in the cytosol of resting phagocytes, and gp91-phox and p22-phox, constituting the membrane-bound cytochrome b(558). In an X-linked CGD patient we identified a novel missense mutation predicting an Asp --> Gly substitution at residue 500 of gp91-phox, associated with normal amounts of nonfunctional cytochrome b(558) in the patient's neutrophils. In PMA-stimulated neutrophils and in a cell-free translocation assay with neutrophil membranes and cytosol, the association of the cytosolic proteins p47-phox and p67-phox with the membrane fraction of the patient was strongly disturbed. Furthermore, a synthetic peptide mimicking domain 491-504 of gp91-phox inhibited NADPH oxidase activity in the cell-free assay (IC50 about 10 mu M), and the translocation of p47-phox and p67-phox in the cell-free translocation assay. We conclude that residue 500 of gp91-phox resides in a region critical for stable binding of p47-phox and p67-phox.