Leusen J H, Bolscher B G, Hilarius P M, Weening R S, Kaulfersch W, Seger R A, Roos D, Verhoeven A J
Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
J Exp Med. 1994 Dec 1;180(6):2329-34. doi: 10.1084/jem.180.6.2329.
Src homology 3 (SH3) domains have been suggested to play an important role in the assembly of the superoxide-forming nicotinamide adenine dinucleotide phosphate (NADPH) oxidase upon activation of phagocytes, which involves the association of membrane-bound and cytosolic components. We studied the translocation of the cytosolic proteins to the plasma membrane in neutrophils of a patient with a point mutation in the gene encoding the light chain of cytochrome b558. This mutation leads to a substitution at residue 156 of a proline into a glutamine in a putative SH3 binding domain of p22-phox (Dinauer, M., E. A. Pierce, R. W. Erickson, T. Muhlebach, H. Messner, R. A. Seger, S. H. Orkin, and J. T. Curnutte. 1991. Proc. Natl. Acad. Sci. 88:11231). In PMA-stimulated neutrophils and in a cell-free translocation assay with neutrophil membranes and cytosol, association of the cytosolic proteins p47-phox and p67-phox with the membrane fraction of the patient's neutrophils was virtually absent. In contrast, when solubilized membranes of the patient's neutrophils were activated with phospholipids in the absence of cytosol (Koshkin, V., and E. Pick. 1993. FEBS [Fed. Eur. Biochem. Soc.] Lett. 327:57), the rate of NADPH-dependent oxygen uptake was observed at a rate similar to that of control membranes. We suggest that the binding of an SH3 domain of p47-phox to p22-phox, and thus activation of the oxidase, does not occur in the neutrophils of this patient, although under artificial conditions, electron flow from NADPH to oxygen in cytochrome b558 is possible.
Src同源结构域3（SH3）被认为在吞噬细胞激活后形成超氧化物的烟酰胺腺嘌呤二核苷酸磷酸（NADPH）氧化酶组装过程中发挥重要作用，这一过程涉及膜结合成分和胞质成分的结合。我们研究了细胞色素b558轻链编码基因发生点突变的患者中性粒细胞中胞质蛋白向质膜的转位情况。该突变导致p22 - phox假定的SH3结合结构域中第156位的脯氨酸被谷氨酰胺取代（迪瑙尔，M.，E. A. 皮尔斯，R. W. 埃里克森，T. 米尔巴赫，H. 梅斯纳，R. A. 塞格，S. H. 奥金，以及J. T. 库尔努特。1991年。《美国国家科学院院刊》88:11231）。在佛波酯（PMA）刺激的中性粒细胞以及中性粒细胞膜和胞质的无细胞转位实验中，患者中性粒细胞的膜部分几乎不存在胞质蛋白p47 - phox和p67 - phox的结合。相比之下，当在无胞质的情况下用磷脂激活患者中性粒细胞的溶解膜时（科什金，V.，以及E. 皮克。1993年。《欧洲生物化学学会联合会快报》327:57），观察到NADPH依赖性氧摄取速率与对照膜相似。我们认为，该患者的中性粒细胞中不存在p47 - phox的SH3结构域与p22 - phox的结合，因此氧化酶未被激活，尽管在人工条件下，细胞色素b558中从NADPH到氧的电子流是可能的。
