The yeast counterparts of human 'MELAS' mutations cause mitochondrial dysfunction that can be rescued by overexpression of the mitochondrial translation factor EF-Tu
The yeast counterparts of human 'MELAS' mutations cause mitochondrial dysfunction that can be rescued by overexpression of the mitochondrial translation factor EF-Tu
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DOI：
10.1038/sj.embor.embor713
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发表时间：
2003-01-01
期刊：
影响因子：
7.7
通讯作者：
Bolotin-Fukuhara, M
中科院分区：
文献类型：
--
作者：
Feuermann, M;Francisci, S;Bolotin-Fukuhara, M
我们利用了人类和酵母菌的相似性（酿酒酵母）线粒体tRNA（Leu）（UUR），以及转化酵母线粒体的可能性，以构建编码tRNA（Leu）（UUR）的基因中的酵母线粒体突变，其等同于已在患有神经变性疾病MELAS的患者中发现的人A3243 G、C3256 T和T3291 C突变（用于线粒体“肌病、脑病、乳酸性酸中毒和中风样发作”）。所得的酵母细胞（携带等同突变A14 G、C26 T和T69 C）在呼吸底物上生长有缺陷，表现出异常的线粒体形态，并且以非常高的速率积累线粒体DNA缺失，这是蛋白质合成中严重线粒体缺陷的特征。这种效应至少在致病突变T69 C中是特异性的，因为当我们引入A或G而不是C时，呼吸缺陷不存在或非常轻微。当突变细胞被携带编码线粒体延伸因子EF-Tu的基因的多拷贝质粒转化时，所有缺陷表型恢复正常。创建和分析这样的突变菌株，并选择正确的基因的能力应该使酵母的一个很好的模型研究的tRNA及其相互作用的合作伙伴和一个实用的工具，用于研究病理突变和tRNA序列多态性。
We have taken advantage of the similarity between human and yeast (Saccharomyces cerevisiae) mitochondrial tRNA(Leu)(UUR), and of the possibility of transforming yeast mitochondria, to construct yeast mitochondrial mutations in the gene encoding tRNA(Leu)(UUR) equivalent to the human A3243G, C3256T and T3291C mutations that have been found in patients with the neurodegenerative disease MELAS (for mitochondrial 'myopathy, encephalopathy, lactic acidosis and stroke-like episodes'). The resulting yeast cells (bearing the equivalent mutations A14G, C26T and T69C) were defective for growth on respiratory substrates, exhibited an abnormal mitochondrial morphology, and accumulated mitochondrial DNA deletions at a very high rate, a trait characteristic of severe mitochondrial defects in protein synthesis. This effect was specific at least in the pathogenic mutation T69C, because when we introduced A or G instead of C, the respiratory defect was absent or very mild. All defective phenotypes returned to normal when the mutant cells were transformed by multicopy plasmids carrying the gene encoding the mitochondrial elongation factor EF-Tu. The ability to create and analyse such mutated strains and to select correcting genes should make yeast a good model for the study of tRNAs and their interacting partners and a practical tool for the study of pathological mutations and of tRNA sequence polymorphisms.