Search for difference in aminoacylation of mitochondrial DNA-encoded wild-type and mutant human tRNALeu (UUR).
The pathogenetic mechanism of the most extensively investigated A3243G mutated tRNALeu(UUR) gene, which causes the MELAS encephalomyopathy, maternally inherited diabetes, or chronic progressive external ophlthalmoplegia, is still unresolved, despite the numerous investigations on the topic. Previous evidences presented in published work suggested that the mitochondrial DNA harboring A3243G mutation result decreases in the rates of mitochondrial protein synthesis. To search for differences in aminoacylation of mitochondrial DNA-encoded wild-type and mutant human tRNALeu(UUR), we have expressed and purified the two kinds of tRNAsLeu(UUR), and have expressed human mitochondrial leucyl-tRNA synthetase for in vitro assays of aminoacylation of wild-type and mutant human tRNALeu(UUR). The results indicate human mitochondrial tRNALeu(UUR) gene A3243G point mutant can remarkably reduce its aminoacylation, suggesting it could be one of the mechanisms that the mutation can produce in such clinical phenotypes.
Wang
Zhen-Cheng
ZC
State Key Laboratory of Molecular Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, People's Republic of China.
Wang
Xue-Min
XM
Jin
You-Xin
YX
Jiao
Bing-Hua
BH
Xu
Feng
F
Miao
Ming-Yong
MY
Zhu
Ke-Jun
KJ
D000215:Acylation; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D017354:Point Mutation; D012356:RNA, Transfer, Leu / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004272:DNA, Mitochondrial; D012356:RNA, Transfer, Leu