Contribution of the tRNAIle 4317A→G mutation to the phenotypic manifestation of the deafness-associated mitochondrial 12S rRNA 1555A→G mutation
| Autor: | Jun Qin Mo, Mi Zhou, Zheyun He, Feilong Meng, Xiaofen Jin, Xiaoyan Ren, Xiaowen Tang, Qiang Shu, Meng Wang, Shasha Gong, Min-Xin Guan, Jing Zheng, Yi Zhu |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Genetics Non-Mendelian inheritance Mitochondrial translation Mitochondrial disease Respiratory chain Cell Biology Mitochondrion Biology medicine.disease Biochemistry Penetrance 03 medical and health sciences 030104 developmental biology Mutation (genetic algorithm) medicine Allele Molecular Biology |
| Zdroj: | Journal of Biological Chemistry. 293:3321-3334 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.ra117.000530 |
| Popis: | The 1555A→G mutation in mitochondrial 12S rRNA has been associated with aminoglycoside-induced and non-syndromic deafness in many individuals worldwide. Mitochondrial genetic modifiers are proposed to influence the phenotypic expression of m.1555A→G mutation. Here, we report that a deafness-susceptibility allele (m.4317A→G) in the tRNAIle gene modulates the phenotype expression of m.1555A→G mutation. Strikingly, a large Han Chinese pedigree carrying both m.4317A→G and m.1555A→G mutations exhibited much higher penetrance of deafness than those carrying only the m.1555A→G mutation. The m.4317A→G mutation affected a highly conserved adenine at position 59 in the T-loop of tRNAIle. We therefore hypothesized that the m.4317A→G mutation alters both structure and function of tRNAIle. Using lymphoblastoid cell lines derived from members of Chinese families (three carrying both m.1555A→G and m.4317A→G mutations, three harboring only m.1555A→G mutation, and three controls lacking these mutations), we found that the cell lines bearing both m.4317A→G and m.1555A→G mutations exhibited more severe mitochondrial dysfunctions than those carrying only the m.1555A→G mutation. We also found that the m.4317A→G mutation perturbed the conformation, stability, and aminoacylation efficiency of tRNAIle. These m.4317A→G mutation-induced alterations in tRNAIle structure and function aggravated the defective mitochondrial translation and respiratory phenotypes associated with the m.1555A→G mutation. Furthermore, mutant cell lines bearing both m.4317A→G and m.1555A→G mutations exhibited greater reductions in the mitochondrial ATP levels and membrane potentials and increasing production of reactive oxygen species than those carrying only the m.1555A→G mutation. Our findings provide new insights into the pathophysiology of maternally inherited deafness arising from the synergy between mitochondrial 12S rRNA and tRNA mutations. |
| Databáze: | OpenAIRE |
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