Entelis N, Kolesnikova O, Kazakova H, Brandina I, Kamenski P, Martin R P, Tarassov I
FRE 2375 of the CNRS (MEPH), Institut de Physiologie et Chimie Biologique 21, rue René Descartes, 67084 Strasbourg, France.
Genet Eng (N Y). 2002;24:191-213. doi: 10.1007/978-1-4615-0721-5_9.
Mitochondria import from the cytoplasm the vast majority of proteins and some RNAs. Although there exists extended knowledge concerning the mechanisms of protein import, the import of RNA is poorly understood. It was almost exclusively studied on the model of tRNA import, in several protozoans, plants and yeast. Mammalian mitochondria, which do not import tRNAs naturally, are hypothesized to import other small RNA molecules from the cytoplasm. We studied tRNA import in the yeast system, both in vitro and in vivo, and applied similar approaches to study 5S rRNA import into human mitochondria. Despite the obvious divergence of RNA import systems suggested for different species, we find that in yeast and human cells this pathway involves similar mechanisms exploiting cytosolic proteins to target the RNA to the organelle and requiring the integrity of pre-protein import apparatus. The import pathway might be of interest from a biomedical point of view, to target into mitochondria RNAs that could suppress pathological mutations in mitochondrial DNA. Yeast represents a good model to elaborate such a gene therapy approach. We have described here the various approaches and protocols to study RNA import into mitochondria of yeast and human cells in vitro and in vivo.
线粒体从细胞质中导入绝大多数蛋白质和一些RNA。尽管关于蛋白质导入机制已有广泛了解，但RNA的导入却知之甚少。几乎仅在几种原生动物、植物和酵母中以tRNA导入模型对其进行了研究。哺乳动物线粒体天然不导入tRNA，据推测其从细胞质中导入其他小RNA分子。我们在酵母系统中对tRNA导入进行了体外和体内研究，并应用类似方法研究5S rRNA导入人线粒体的过程。尽管不同物种的RNA导入系统明显不同，但我们发现，在酵母和人类细胞中，该途径涉及类似机制，利用胞质蛋白将RNA靶向细胞器，并需要前体蛋白导入装置的完整性。从生物医学角度来看，导入途径可能具有重要意义，可将能够抑制线粒体DNA病理突变的RNA靶向导入线粒体。酵母是阐述这种基因治疗方法的良好模型。我们在此描述了体外和体内研究RNA导入酵母和人类细胞线粒体的各种方法和方案。
