Ahmed Afsar U, Fisher Paul R
Department of Microbiology, La Trobe University, Victoria, Australia.
Int Rev Cell Mol Biol. 2009;273:49-68. doi: 10.1016/S1937-6448(08)01802-9.
A growing amount of evidence suggests that the cytosolic translation of nuclear-encoded mitochondrial proteins and their subsequent import into mitochondria are tightly coupled in a process termed cotranslational import. In addition to the original posttranslational view of mitochondrial protein import, early literature also provides both in vitro and in vivo experimental evidence supporting the simultaneous existence of a cotranslational protein-import mechanism in mitochondria. Recent investigations have started to reveal the cotranslational import mechanism which is initiated by transporting either a translation complex or a translationally competent mRNA encoding a mitochondrial protein to the mitochondrial surface. The intracellular localization of mRNA to the mitochondrial surface has emerged as the latest addition to our understanding of mitochondrial biogenesis. It is mediated by targeting elements within the mRNA molecule in association with potential mRNA-binding proteins.
越来越多的证据表明，核编码线粒体蛋白的胞质翻译及其随后导入线粒体的过程在一个称为共翻译导入的过程中紧密耦合。除了最初的线粒体蛋白导入的翻译后观点外，早期文献还提供了体外和体内实验证据，支持线粒体中共翻译蛋白导入机制的同时存在。最近的研究开始揭示共翻译导入机制，该机制是通过将翻译复合物或编码线粒体蛋白的具有翻译能力的mRNA转运到线粒体表面而启动的。mRNA在线粒体表面的细胞内定位已成为我们对线粒体生物发生理解的最新补充。它是由mRNA分子内的靶向元件与潜在的mRNA结合蛋白共同介导的。
