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Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency
Mitochondrial tRNA 3’-end metabolism is critical for the formation of functional tRNAs. Deficient mitochondrial tRNA 3’-end metabolism is linked to an array of human diseases, including optic neuropathy, but their pathophysiology remains poorly understood. In this report, we investigated the molecul...
Autores principales: | , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Society for Biochemistry and Molecular Biology
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8212662/ https://www.ncbi.nlm.nih.gov/pubmed/34023389 http://dx.doi.org/10.1016/j.jbc.2021.100816 |
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author | Ji, Yanchun Nie, Zhipeng Meng, Feilong Hu, Cuifang Chen, Hui Jin, Lihao Chen, Mengquan Zhang, Minglian Zhang, Juanjuan Liang, Min Wang, Meng Guan, Min-Xin |
author_facet | Ji, Yanchun Nie, Zhipeng Meng, Feilong Hu, Cuifang Chen, Hui Jin, Lihao Chen, Mengquan Zhang, Minglian Zhang, Juanjuan Liang, Min Wang, Meng Guan, Min-Xin |
author_sort | Ji, Yanchun |
collection | PubMed |
description | Mitochondrial tRNA 3’-end metabolism is critical for the formation of functional tRNAs. Deficient mitochondrial tRNA 3’-end metabolism is linked to an array of human diseases, including optic neuropathy, but their pathophysiology remains poorly understood. In this report, we investigated the molecular mechanism underlying the Leber’s hereditary optic neuropathy (LHON)-associated tRNA(Ala) 5587A>G mutation, which changes a highly conserved adenosine at position 73 (A73) to guanine (G73) on the 3’-end of the tRNA acceptor stem. The m.5587A>G mutation was identified in three Han Chinese families with suggested maternal inheritance of LHON. We hypothesized that the m.5587A>G mutation altered tRNA(Ala) 3’-end metabolism and mitochondrial function. In vitro processing experiments showed that the m.5587A>G mutation impaired the 3’-end processing of tRNA(Ala) precursors by RNase Z and inhibited the addition of CCA by tRNA nucleotidyltransferase (TRNT1). Northern blot analysis revealed that the m.5587A>G mutation perturbed tRNA(Ala) aminoacylation, as evidenced by decreased efficiency of aminoacylation and faster electrophoretic mobility of mutated tRNA(Ala) in these cells. The impact of m.5587A>G mutation on tRNA(Ala) function was further supported by increased melting temperature, conformational changes, and reduced levels of this tRNA. Failures in tRNA(Ala) metabolism impaired mitochondrial translation, perturbed assembly and activity of oxidative phosphorylation complexes, diminished ATP production and membrane potential, and increased production of reactive oxygen species. These pleiotropic defects elevated apoptotic cell death and promoted mitophagy in cells carrying the m.5587A>G mutation, thereby contributing to visual impairment. Our findings may provide new insights into the pathophysiology of LHON arising from mitochondrial tRNA 3’-end metabolism deficiency. |
format | Online Article Text |
id | pubmed-8212662 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | American Society for Biochemistry and Molecular Biology |
record_format | MEDLINE/PubMed |
spelling | pubmed-82126622021-06-25 Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency Ji, Yanchun Nie, Zhipeng Meng, Feilong Hu, Cuifang Chen, Hui Jin, Lihao Chen, Mengquan Zhang, Minglian Zhang, Juanjuan Liang, Min Wang, Meng Guan, Min-Xin J Biol Chem Research Article Mitochondrial tRNA 3’-end metabolism is critical for the formation of functional tRNAs. Deficient mitochondrial tRNA 3’-end metabolism is linked to an array of human diseases, including optic neuropathy, but their pathophysiology remains poorly understood. In this report, we investigated the molecular mechanism underlying the Leber’s hereditary optic neuropathy (LHON)-associated tRNA(Ala) 5587A>G mutation, which changes a highly conserved adenosine at position 73 (A73) to guanine (G73) on the 3’-end of the tRNA acceptor stem. The m.5587A>G mutation was identified in three Han Chinese families with suggested maternal inheritance of LHON. We hypothesized that the m.5587A>G mutation altered tRNA(Ala) 3’-end metabolism and mitochondrial function. In vitro processing experiments showed that the m.5587A>G mutation impaired the 3’-end processing of tRNA(Ala) precursors by RNase Z and inhibited the addition of CCA by tRNA nucleotidyltransferase (TRNT1). Northern blot analysis revealed that the m.5587A>G mutation perturbed tRNA(Ala) aminoacylation, as evidenced by decreased efficiency of aminoacylation and faster electrophoretic mobility of mutated tRNA(Ala) in these cells. The impact of m.5587A>G mutation on tRNA(Ala) function was further supported by increased melting temperature, conformational changes, and reduced levels of this tRNA. Failures in tRNA(Ala) metabolism impaired mitochondrial translation, perturbed assembly and activity of oxidative phosphorylation complexes, diminished ATP production and membrane potential, and increased production of reactive oxygen species. These pleiotropic defects elevated apoptotic cell death and promoted mitophagy in cells carrying the m.5587A>G mutation, thereby contributing to visual impairment. Our findings may provide new insights into the pathophysiology of LHON arising from mitochondrial tRNA 3’-end metabolism deficiency. American Society for Biochemistry and Molecular Biology 2021-05-21 /pmc/articles/PMC8212662/ /pubmed/34023389 http://dx.doi.org/10.1016/j.jbc.2021.100816 Text en © 2021 The Authors https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
spellingShingle | Research Article Ji, Yanchun Nie, Zhipeng Meng, Feilong Hu, Cuifang Chen, Hui Jin, Lihao Chen, Mengquan Zhang, Minglian Zhang, Juanjuan Liang, Min Wang, Meng Guan, Min-Xin Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency |
title | Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency |
title_full | Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency |
title_fullStr | Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency |
title_full_unstemmed | Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency |
title_short | Mechanistic insights into mitochondrial tRNA(Ala) 3’-end metabolism deficiency |
title_sort | mechanistic insights into mitochondrial trna(ala) 3’-end metabolism deficiency |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8212662/ https://www.ncbi.nlm.nih.gov/pubmed/34023389 http://dx.doi.org/10.1016/j.jbc.2021.100816 |
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