哺乳动物细胞中异位表达线粒体基因MT-ND3

Allotopic Expression of Mitochondrial Gene MT-ND3 in Mammalian Cells

线粒体DNA(mitochondrial DNA,mtDNA)突变是导致线粒体疾病的重要因素,目前针对这一类疾病还没有有效的治疗方案。在细胞质中表达线粒体基因称为线粒体基因的异位表达,被认为是一种潜在的治疗mtDNA疾病的方法,但并没有一种统一的信号肽能够将所有线粒体基因导入至线粒体中。本研究探讨了利用异位表达将线粒体蛋白ND3定位至线粒体的可行性,主要发现:(1)在无信号肽的情况下,ND3蛋白自身并不能定位至线粒体,而是定位在内质网上;(2)Rg9mtd1的信号肽可以将ND3蛋白成功导入线粒体中;(3)定位至线粒体的ND3蛋白对线粒体膜电位、活性氧的产生以及细胞增殖均无显著影响,但对线粒体基因的表达方式有调整作用。以上结果表明,异位表达ND3质粒能正确表达和定位,并具有一定的功能性,这为MT-ND3异位表达治疗相关疾病提供了理论支持和技术方案。

Mitochondrial DNA(mtDNA)mutations are the main causes for mitochondrial diseases,for which effective treatment is still missing.Mitochondrial gene expression in cytoplasm is termed as allotopic expression,which is thought to be the potential treatment for mtDNA-related diseases.However,there is no one single signal peptide for all the various mitochondrial proteins which are guided to the mitochondria.In this study,we investigated the feasibility that using allotopic expression introduces the mitochondrial protein ND3 into mitochondria.Some results were obtained as below:firstly,without signal peptide,ND3 itself localized to endoplasmic reticulum(ER)instead of mitochondria;secondly,signal peptide from Rg9mtd1 could successfully target ND3 to mitochondria;thirdly,ND3 localized to mitochondria had no effect on mitochondrial membrane potential,reactive oxygen species and cell proliferation,but regulated the expression pattern of mitochondrial genes.All the results indicated allotopic expression plasmid for ND3 could express the correct protein which can localize exactly to mitochondria and perform some functions.Our study will provide the theoretical basis and guidance for the treatment of related diseases by using allotopic expression of MT-ND3.