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Nucleic Acids Res. 2014 Jul;42(12):8039-48. doi: 10.1093/nar/gku466. Epub 2014 Jun 11.

A deafness-associated tRNAHis mutation alters the mitochondrial function, ROS production and membrane potential.

Author information

1
Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058.
2
Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058 Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229.
3
Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229.
4
Department of Otology and Skull Base Surgery, Eye and ENT Hospital, Fudan University, Shanghai, China 200031.
5
Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China 310058 Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA 45229 gminxin88@zju.edu.cn Min-Xin.Guan@cchmc.org lihw@yahoo.com.cn.

Abstract

In this report, we investigated the molecular genetic mechanism underlying the deafness-associated mitochondrial tRNAHis 12201T>C mutation. The destabilization of a highly conserved base-pairing (5A-68U) by the m.12201T>C mutation alters structure and function of tRNAHis. Using cybrids constructed by transferring mitochondria from lymphoblastoid cell lines derived from a Chinese family into mtDNA-less (ρo) cells, we showed ∼70% decrease in the steady-state level of tRNAHis in mutant cybrids, compared with control cybrids. The mutation changed the conformation of tRNAHis, as suggested by slower electrophoretic mobility of mutated tRNA with respect to the wild-type molecule. However, ∼60% increase in aminoacylated level of tRNAHis was observed in mutant cells. The failure in tRNAHis metabolism was responsible for the variable reductions in seven mtDNA-encoded polypeptides in mutant cells, ranging from 37 to 81%, with the average of ∼46% reduction, as compared with those of control cells. The impaired mitochondrial translation caused defects in respiratory capacity in mutant cells. Furthermore, marked decreases in the levels of mitochondrial ATP and membrane potential were observed in mutant cells. These mitochondrial dysfunctions caused an increase in the production of reactive oxygen species in the mutant cells. The data provide the evidence for a mitochondrial tRNAHis mutation leading to deafness.

PMID:
24920829
PMCID:
PMC4081083
DOI:
10.1093/nar/gku466
[Indexed for MEDLINE]
Free PMC Article

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