Omura T
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka, Fukuoka, 812-8582, Japan.
J Biochem. 1998 Jun;123(6):1010-6. doi: 10.1093/oxfordjournals.jbchem.a022036.
The intracellular sorting of newly synthesized precursor proteins (preproteins) to mitochondria depends on the "mitochondria-targeting sequence" (MTS), which is located at the amino termini of the preproteins. MTS is required, however, not only for targeting newly synthesized preproteins to mitochondria, but also for all the following steps along the mitochondrial protein import pathway. MTS of nascent preproteins is first recognized by a cytoplasmic molecular chaperone, MSF, and then by Tom70 and Tom20 of the mitochondrial outer membrane receptor complex, Tom5 and Tom40 of the outer membrane protein translocation machinery, Tim23 of the inner membrane protein translocation machinery, and finally the processing peptidase, MPP, in the matrix. MTS is a multi-role sorting sequence which specifically interacts with various components along the mitochondrial protein import pathway. Recognition of MTS at multiple steps during the import of preproteins may contribute to the strict sorting of proteins destined for mitochondria.
新合成的前体蛋白（前蛋白）向线粒体的细胞内分选取决于位于前蛋白氨基末端的“线粒体靶向序列”（MTS）。然而，MTS不仅是将新合成的前蛋白靶向线粒体所必需的，而且对于线粒体蛋白导入途径中的所有后续步骤也是必需的。新生前蛋白的MTS首先被细胞质分子伴侣MSF识别，然后被线粒体外膜受体复合物的Tom70和Tom20、外膜蛋白转运机制的Tom5和Tom40、内膜蛋白转运机制的Tim23识别，最后被基质中的加工肽酶MPP识别。MTS是一个具有多种作用的分选序列，它与线粒体蛋白导入途径中的各种成分特异性相互作用。在前蛋白导入过程中的多个步骤对MTS的识别可能有助于严格分选注定进入线粒体的蛋白。
