Human mitochondrial leucyl-tRNA synthetase corrects mitochondrial dysfunctions due to the tRNALeu(UUR) A3243G mutation, associated with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like symptoms and diabetes.
نویسندگان
چکیده
Mutations in mitochondrial tRNA genes are associated with a wide spectrum of human diseases. In particular, the tRNA(Leu(UUR)) A3243G mutation causes mitochondrial encephalomyopathy, lactic acidosis, and stroke-like symptoms (MELAS) and 2% of cases of type 2 diabetes. The primary defect in this mutation was an inefficient aminoacylation of the tRNA(Leu(UUR)). In the present study, we have investigated the molecular mechanism of the A3243G mutation and whether the overexpression of human mitochondrial leucyl-tRNA synthetase (LARS2) in the cytoplasmic hybrid (cybrid) cells carrying the A3243G mutation corrects the mitochondrial dysfunctions. Human LARS2 localizes exclusively to mitochondria, and LARS2 is expressed ubiquitously but most abundantly in tissues with high metabolic rates. We showed that the alteration of aminoacylation tRNA(Leu(UUR)) caused by the A3243G mutation led to mitochondrial translational defects and thereby reduced the aminoacylated efficiencies of tRNA(Leu(UUR)) as well as tRNA(Ala) and tRNA(Met). We demonstrated that the transfer of human mitochondrial leucyl-tRNA synthetase into the cybrid cells carrying the A3243G mutation improved the efficiency of aminoacylation and stability of mitochondrial tRNAs and then increased the rates of mitochondrial translation and respiration, consequently correcting the mitochondrial dysfunction. These findings provide new insights into the molecular mechanism of maternally inherited diseases and a step toward therapeutic interventions for these disorders.
منابع مشابه
Human Mitochondrial Leucyl-tRNA Synthetase Corrects Mitochondrial Dysfunctions Due to the tRNA A3243G Mutation, Associated with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Symptoms and Diabetes
Human Mitochondrial Leucyl-tRNA Synthetase Corrects Mitochondrial Dysfunctions Due to the tRNA A3243G Mutation, Associated with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Symptoms and Diabetes Ronghua Li and Min-Xin Guan* Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, and Department of Pediatrics, University of Cincinnati Coll...
متن کاملLack of Association of Mitochondrial A3243G tRNALeu Mutation in Iranian Patients with Type 2 Diabetes
Many kinds of mutations in mitochondrial (mt) DNA have been reported to be related to the development of Diabetes Mellitus (DM), this type of diabetes has also been shown to be influenced by other genetic factors and/or environmental factors. Among them, tRNALeu(UUR) and its adjacent mtDNA NADH dehydrogenase subunit 1(ND1) region within the mt genome are linked to high susceptibility to DM. A p...
متن کاملThe A to G transition at nt 3243 of the mitochondrial tRNALeu(UUR) may cause an MERRF syndrome.
OBJECTIVE To verify the phenotype to genotype correlations of mitochondrial DNA (mtDNA) related disorders in an atypical maternally inherited encephalomyopathy. METHODS Neuroradiological, morphological, biochemical, and molecular genetic analyses were performed on the affected members of a pedigree harbouring the heteroplasmic A to G transition at nucleotide 3243 of the mitochondrial tRNALeu(...
متن کاملThe A to G transition at nt 3243 of the mitochondrial tRNALeu ( uuR ) may cause an MERRF syndrome Gian
Received 31 October 1995 and in final revised form 19 February 1996 Accepted 23 February 1996 Abstract Objective-To verify the phenotype to genotype correlations of mitochondrial DNA (mtDNA) related disorders in an atypical maternally inherited encephalomyopathy. Methods-Neuroradiological, morphological, biochemical, and molecular genetic analyses were performed on the affected members of a ped...
متن کاملAcquisition of the wobble modification in mitochondrial tRNALeu(CUN) bearing the G12300A mutation suppresses the MELAS molecular defect.
The A3243G mutation in the mitochondrial gene for human mitochondrial (mt) tRNA(Leu(UUR)), responsible for decoding of UUR codons, is associated with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). We previously demonstrated that this mutation causes defects in 5-taurinomethyluridine (taum(5)U) modification at the anticodon first (wobble) position of th...
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ورودعنوان ژورنال:
- Molecular and cellular biology
دوره 30 9 شماره
صفحات -
تاریخ انتشار 2010