Mutations in C12orf65 in Patients with Encephalomyopathy and a Mitochondrial Translation Defect
详细信息 查看全文
- 作者：Hana Antonicka ; Elsebet Ø ; stergaard ; Florin Sasarman ; Woranontee Weraarpachai ; Flemming Wibr ; Anne Marie B. Pedersen ; Richard J. Rodenburg ; Marjo S. van der Knaap ; Jan A.M. Smeitink ; Zofia M. Chr
- 刊名：The American Journal of Human Genetics
- 出版年：2010
- 出版时间：9 July 2010
- 年：2010
- 卷：87
- 期：1
- 页码：115-122
- 全文大小：1036 K
文摘
We investigated the genetic basis for a global and uniform decrease in mitochondrial translation in fibroblasts from patients in two unrelated pedigrees who developed Leigh syndrome, optic atrophy, and ophthalmoplegia. Analysis of the assembly of the oxidative phosphorylation complexes showed severe decreases of complexes I, IV, and V and a smaller decrease in complex III. The steady-state levels of mitochondrial mRNAs, tRNAs, and rRNAs were not reduced, nor were those of the mitochondrial translation elongation factors or the protein components of the mitochondrial ribosome. Using homozygosity mapping, we identified a 1 bp deletion in C12orf65 in one patient, and DNA sequence analysis showed a different 1 bp deletion in the second patient. Both mutations predict the same premature stop codon. C12orf65 belongs to a family of four mitochondrial class I peptide release factors, which also includes mtRF1a, mtRF1, and Ict1, all characterized by the presence of a GGQ motif at the active site. However, C12orf65 does not exhibit peptidyl-tRNA hydrolase activity in an in vitro assay with bacterial ribosomes. We suggest that it might play a role in recycling abortive peptidyl-tRNA species, released from the ribosome during the elongation phase of translation.