1. Overexpression of mitochondrial histidyl-tRNA synthetase restores mitochondrial dysfunction caused by a deafness-associated tRNA
- Author
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Feilong Meng, Zhiyi Cai, Jun Qin Mo, Min-Xin Guan, Qiuzi Yi, Limei Cui, Xiaohui Cang, Shasha Gong, Qiong Zhao, Xiaoqiong Wang, and Yong Liang
- Subjects
Mitochondrial translation ,Mitochondrial disease ,RNA Stability ,Cell Respiration ,Aminoacylation ,Oxidative phosphorylation ,Deafness ,Molecular Dynamics Simulation ,medicine.disease_cause ,Nucleic Acid Denaturation ,RNA, Transfer, His ,Biochemistry ,Cytoplasmic hybrid ,DNA, Mitochondrial ,Cell Line ,Amino Acyl-tRNA Synthetases ,Electron Transport ,Mitochondrial Proteins ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Adenosine Triphosphate ,medicine ,Humans ,RNA, Messenger ,Molecular Biology ,030304 developmental biology ,Membrane Potential, Mitochondrial ,0303 health sciences ,Mutation ,Aminoacyl tRNA synthetase ,Cell Biology ,medicine.disease ,Cell biology ,Mitochondria ,chemistry ,RNA, Ribosomal ,Transfer RNA ,Nucleic Acid Conformation ,RNA ,Reactive Oxygen Species ,030217 neurology & neurosurgery ,Subcellular Fractions - Abstract
The deafness-associated m.12201T>C mutation affects the A5-U68 base-pairing within the acceptor stem of mitochondrial tRNAHis. The primary defect in this mutation is an alteration in tRNAHisaminoacylation. Here, we further investigate the molecular mechanism of the deafness-associated tRNAHis12201T>C mutation and test whether the overexpression of the human mitochondrial histidyl-tRNA synthetase gene (HARS2) in cytoplasmic hybrid (cybrid) cells carrying the m.12201T>C mutation reverses mitochondrial dysfunctions. Using molecular dynamics simulations, we demonstrate that the m.12201T>C mutation perturbs the tRNAHisstructure and function, supported by decreased melting temperature, conformational changes, and instability of mutated tRNA. We show that the m.12201T>C mutation-induced alteration of aminoacylation tRNAHiscauses mitochondrial translational defects and respiratory deficiency. We found that the transfer ofHARS2into the cybrids carrying the m.12201T>C mutation raises the levels of aminoacylated tRNAHisfrom 56.3 to 75.0% but does not change the aminoacylation of other tRNAs. Strikingly,HARS2overexpression increased the steady-state levels of tRNAHisand of noncognate tRNAs, including tRNAAla, tRNAGln, tRNAGlu, tRNALeu(UUR), tRNALys, and tRNAMet, in cells bearing the m.12201T>C mutation. This improved tRNA metabolism elevated the efficiency of mitochondrial translation, activities of oxidative phosphorylation complexes, and respiration capacity. Furthermore,HARS2overexpression markedly increased mitochondrial ATP levels and membrane potential and reduced production of reactive oxygen species in cells carrying the m.12201T>C mutation. These results indicate thatHARS2overexpression corrects the mitochondrial dysfunction caused by the tRNAHismutation. These findings provide critical insights into the pathophysiology of mitochondrial disease and represent a step toward improved therapeutic interventions for mitochondrial disorders.
- Published
- 2019