Enriquez J A, Chomyn A, Attardi G
Division of Biology, California Institute of Technology, Pasadena 91125, USA.
Nat Genet. 1995 May;10(1):47-55. doi: 10.1038/ng0595-47.
We have investigated the pathogenetic mechanism of the mitochondrial tRNA(Lys) gene mutation (position 8344) associated with MERRF encephalomyopathy in several mitochondrial DNA (mtDNA)-less cell transformants carrying the mutation and in control cells. A decrease of 50-60% in the specific tRNA(Lys) aminoacylation capacity per cell was found in mutant cells. Furthermore, several lines of evidence reveal that the severe protein synthesis impairment in MERRF mutation-carrying cells is due to premature termination of translation at each or near each lysine codon, with the deficiency of aminoacylated tRNA(Lys) being the most likely cause of this phenomenon.
我们已经在几种携带该突变的线粒体DNA（mtDNA）缺失的细胞转化体以及对照细胞中，研究了与肌阵挛性癫痫伴破碎红纤维（MERRF）脑病相关的线粒体tRNA（Lys）基因突变（8344位点）的致病机制。在突变细胞中，发现每个细胞的特异性tRNA（Lys）氨酰化能力降低了50 - 60%。此外，多条证据表明，携带MERRF突变的细胞中严重的蛋白质合成障碍是由于在每个赖氨酸密码子处或其附近翻译提前终止所致，氨酰化tRNA（Lys）的缺乏是这种现象最可能的原因。
