Import of carrier proteins into the mitochondrial Inner membrane mediated by Tim22
Import of carrier proteins into the mitochondrial Inner membrane mediated by Tim22
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DOI：
10.1038/384582a0
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发表时间：
1996-12-12
期刊：
影响因子：
64.8
通讯作者：
Brunner, M
中科院分区：
文献类型：
--
作者：
Sirrenberg, C;Bauer, MF;Brunner, M
线粒体前蛋白跨内膜的移位由TIM机制促进(1-8)。Tim34与基质靶向信号结合并启动膜电位依赖的导入(8)。TIM23和TIM17是跨越内膜的易位通道的组成部分(6)。Tim44在基质侧与这个通道相关(6)，Tim44招募线粒体Hsp70及其辅助伴侣Mge1，后者利用ATP作为能量来源推动蛋白质转位到基质中(9-14)。TIM22是线粒体输入机制中的一个新成员，与TIM23和TIM17具有序列相似性。在此，我们报道了线粒体ADP/ATP载体(AAC)家族的蛋白质进入内膜所需的Tim22。酵母AAC家族的成员在没有基质靶向信号(15，16)的情况下被合成。TIM22是一个高相对分子质量的组件，不同于TIM23-TIM17络合物(6)。AAC家族蛋白的导入不依赖于TIM23，而包含前蛋白的基质靶向信号的导入不依赖于Tim22。
TRANSLOCATION of mitochondrial preproteins across the inner membrane is facilitated by the TIM machinery(1-8). Tim34 binds to matrix targeting signals and initiates membrane potential-dependent import(8). Tim23 and Tim17 are constituents of a translocation channel across the inner membrane(6). Tim44 is associated with this channel at the matrix side(6), and Tim44 recruits mitochondrial Hsp70 and its co-chaperone Mge1, which drive protein translocation into the matrix using ATP as an energy source(9-14). Tim22 is a new component of the import machinery of mitochondria, which shares sequence similarity with both Tim23 and Tim17. Here we report that Tim22 is required for the import of proteins of the mitochondrial ADP/ATP carrier (AAC) family into the inner membrane. Members of the yeast AAC family are synthesized without matrix targeting signals(15,16). Tim22 is in an assembly of high relative molecular mass that is distinct from the Tim23-Tim17 complex(6). Import of proteins of the AAC family is independent of Tim23, and import of matrix targeting signals containing preproteins is independent of Tim22.