The C-terminal region of TIM17 links the outer and inner mitochondrial membranes in Arabidopsis and is essential for protein import
The C-terminal region of TIM17 links the outer and inner mitochondrial membranes in Arabidopsis and is essential for protein import
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DOI：
10.1074/jbc.m413299200
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发表时间：
2005-04-22
影响因子：
4.8
通讯作者：
Whelan, J
中科院分区：
文献类型：
--
作者：
Murcha, MW;Elhafez, D;Whelan, J
来自拟南芥的内膜转位酶17（AtTIM 17 -2）蛋白已被证明连接线粒体外膜和内膜。这一点通过几种方法得到了证明：（i）体外细胞器导入测定表明，导入的AtTIM 17 -2蛋白在插入内膜时仍然可以在外膜中被蛋白酶接近。(ii)N-末端和C-末端标记表明C-末端区域位于外膜。(iii)抗体的C-末端100个氨基酸识别纯化的线粒体的31 kDa的蛋白质，但交叉反应性被废除时，线粒体蛋白酶处理，以去除外膜暴露的蛋白质。AtTIM 17 -2的抗体抑制蛋白质通过一般进口途径进入外膜破裂的线粒体，但不抑制蛋白质通过载体进口途径进口。这些结果共同表明AtTIM 17 -2的C-末端区域暴露在外膜的外表面上，并且C-末端区域对于蛋白质输入到线粒体中是必需的。
The translocase of the inner membrane 17 (AtTIM17-2) protein from Arabidopsis has been shown to link the outer and inner mitochondrial membranes. This was demonstrated by several approaches: (i) In vitro organelle import assays indicated the imported AtTIM17-2 protein remained protease accessible in the outer membrane when inserted into the inner membrane. (ii) N-terminal and C-terminal tagging indicated that it was the C-terminal region that was located in the outer membrane. (iii) Antibodies raised to the C-terminal 100 amino acids recognize a 31-kDa protein from purified mitochondria, but cross-reactivity was abolished when mitochondria were protease-treated to remove outer membrane-exposed proteins. Antibodies to AtTIM17-2 inhibited import of proteins via the general import pathway into outer membrane-ruptured mitochondria, but did not inhibit protein import via the carrier import pathway. Together these results indicate that the C-terminal region of AtTIM17-2 is exposed on the outer surface of the outer membrane, and the C-terminal region is essential for protein import into mitochondria.