Identification of an actin-binding site in p47phox an organizer protein of NADPH oxidase
Identification of an actin-binding site in p47phox an organizer protein of NADPH oxidase
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DOI：
10.1016/j.febslet.2005.11.080
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发表时间：
2006-01-09
期刊：
影响因子：
3.5
通讯作者：
Oku, S
中科院分区：
文献类型：
--
作者：
Tamura, M;Itoh, K;Oku, S
肌动蛋白能增强中性粒细胞NADPH氧化酶在无细胞体系中产生超氧化物的活性，并与氧化酶的调节亚基p47（phox）相互作用。在本研究中，我们寻找肌动蛋白结合位点的p47（phox）的远蛋白印迹和印迹结合试验使用截短形式的p47（phox）。氨基酸序列319-337被鉴定为肌动蛋白结合位点，并且该序列的合成肽与肌动蛋白结合。该序列与其他已知的肌动蛋白结合基序没有同源性。它位于p47（phox）的自抑制区，包括Ser-328，一个对解蔽至关重要的磷酸化位点。虽然磷酸化模拟p47（phox）突变体绑定到肌动蛋白的亲和力比野生型低，相同的突变体与丝状肌动蛋白的相互作用比野生型更有效。突变肽p47（phox）（319-337，Ser 328 Glu）与丝状肌动蛋白的结合比与单体肌动蛋白的结合更紧密。这些结果表明，p47（phox）移动到皮质肌动蛋白时，它成为在细胞中的解蔽。(c)2005年欧洲生物化学学会联合会。Elsevier B. V.出版，保留所有权利。
Actin has been reported to enhance the superoxidegenerating activity of neutrophil NADPH oxidase in a cell-free system and to interact with p47(phox), a regulatory subunit of the oxidase. In the present study, we searched for an actin-binding site in p47(phox) by far-western blotting and blot-binding assays using truncated forms of p47(phox). The amino-acid sequence 319-337 was identified as an actin-binding site, and a synthetic peptide of this sequence bound to actin. The sequence shows no homology to other known actin-binding motifs. It is located in the autoinhibitory region of p47(phox) and includes Ser-328, a phosphorylation site essential for unmasking. Although a phosphorylation-mimetic p47(phox) mutant bound to actin with a lower affinity than the wild type, the same mutant interacted with filamentous actin more efficiently than the wild type. A mutant peptide p47(phox) (319-337, Ser328Glu) bound to filamentous actin more tightly than to monomer actin. These results suggest that p47(phox) Moves to cortical actin when it becomes unmasked in the cells. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.