Essential role of Mia40 in import and assembly of mitochondrial intermembrane space proteins
Essential role of Mia40 in import and assembly of mitochondrial intermembrane space proteins
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DOI：
10.1038/sj.emboj.7600389
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发表时间：
2004-09-29
期刊：
影响因子：
11.4
通讯作者：
Pfanner, N
中科院分区：
文献类型：
--
作者：
Chacinska, A;Pfannschmidt, S;Pfanner, N
线粒体将核编码的前体蛋白输入到四个不同的亚区室。已经确定了特定的输入机制，将前体蛋白分别引导至线粒体外膜、内膜或基质。然而，一个专门用于进口的线粒体膜间空间（IMS）蛋白的机器迄今尚未发现。我们已经鉴定了必需的IMS蛋白Mia 40（由酿酒酵母开放阅读框架YKL 195 w编码）。具有Mia40突变形式的线粒体在几种小IMS蛋白的输入中被选择性地抑制，包括必需蛋白Tim9和Tim10。蛋白质的进口到其他线粒体亚区室不依赖于功能Mia40。小Tim蛋白与Mia40的结合对于它们跨外膜的运输至关重要，并且代表了它们组装成IMS复合物的初始步骤。我们的结论是，Mia40是一个核心组成部分的蛋白质进口和组装机械的线粒体IMS。
Mitochondria import nuclear-encoded precursor proteins to four different subcompartments. Specific import machineries have been identified that direct the precursor proteins to the mitochondrial outer membrane, inner membrane or matrix, respectively. However, a machinery dedicated to the import of mitochondrial intermembrane space (IMS) proteins has not been found so far. We have identified the essential IMS protein Mia40 (encoded by the Saccharomyces cerevisiae open reading frame YKL195w). Mitochondria with a mutant form of Mia40 are selectively inhibited in the import of several small IMS proteins, including the essential proteins Tim9 and Tim10. The import of proteins to the other mitochondrial subcompartments does not depend on functional Mia40. The binding of small Tim proteins to Mia40 is crucial for their transport across the outer membrane and represents an initial step in their assembly into IMS complexes. We conclude that Mia40 is a central component of the protein import and assembly machinery of the mitochondrial IMS.