In this report, we investigated the pathophysiology of a novel hypertension-associated mitochondrial tRNA(Ala) 5655A → G (m.5655A → G) mutation. The destabilization of a highly conserved base pairing (A1-U72) at the aminoacyl acceptor stem by an m.5655A → G mutation altered the tRNA(Ala) function. An in vitro processing analysis showed that the m.5655A → G mutation reduced the efficiency of tRN...

Transcription of the mitochondrial genome results in polycistronic precursors, which are processed mainly by the release of tRNAs interspersed between rRNAs and mRNAs. In many metazoan mitochondrial genomes some tRNA genes overlap with downstream genes; in the case of human mitochondria the genes for tRNA(Tyr) and tRNA(Cys) overlap by one nucleotide. It has previously been shown that processing...

Two mutations (G8363A and A8296G) in the mtDNA (mitochondrial DNA) tRNA(Lys) gene have been associated with severe mitochondrial diseases in a number of reports. Their functional significance, however, remains unknown. We have already shown that homoplasmic cybrids harbouring the A8296G mutation display normal oxidative phosphorylation, although the possibility of a subtle change in mitochondri...

In bean, potato, and Oenothera plants, the C encoded at position 4 (C4) in the mitochondrial tRNA Phe GAA gene is converted into a U in the mature tRNA. This nucleotide change corrects a mismatched C4-A69 base pair which appears when the gene sequence is folded into the cloverleaf structure. C-to-U conversions constitute the most common editing events occurring in plant mitochondrial mRNAs. Whi...

The intracellular distribution of glutaminyl-tRNA synthetases and their role in mitochondrial tRNA import were evaluated in the ancient eukaryote Leishmania tarentolae. The following results were obtained: (i) Glutaminyl-tRNA synthetase was detected in leishmanial mitochondria. This was unexpected because it has been postulated that, in organelles, Gln-tRNAGln is not formed by direct acylation ...

Background Atherosclerosis is a disease that affects large and medium size arteries in the body that underlies coronary heart disease. Several nucleotide changes in mitochondrial tRNA genes have been reported in various diseases. The purpose of the study was to identify hotspot mitochondrial tRNA mutations in atherosclerotic patients. Methods In this case-control study, the variations of ten ...

The 16,775 base-pair mitochondrial genome of the white Leghorn chicken has been cloned and sequenced. The avian genome encodes the same set of genes (13 proteins, 2 rRNAs and 22 tRNAs) as do other vertebrate mitochondrial DNAs and is organized in a very similar economical fashion. There are very few intergenic nucleotides and several instances of overlaps between protein or tRNA genes. The prot...

MTU1 (TRMU) is a mitochondrial enzyme responsible for the 2-thiolation of the wobble U in tRNA(Lys), tRNA(Glu) and tRNA(Gln), a post-transcriptional modification believed to be important for accurate and efficient synthesis of the 13 respiratory chain subunits encoded by mtDNA. Mutations in MTU1 are associated with acute infantile liver failure, and this has been ascribed to a transient lack of...

Mutations in mitochondrial DNA-encoded tRNA genes are associated with many human diseases. Activation of peroxisome proliferator-activated receptors (PPARs) by synthetic agonists stimulates oxidative metabolism, induces an increase in mitochondrial mass and partially compensates for oxidative phosphorylation system (OXPHOS) defects caused by single OXPHOS enzyme deficiencies in vitro and in viv...

BACKGROUND Animal mitochondrial genomes typically encode one tRNA for each synonymous codon family, so that each tRNA anticodon essentially has to wobble to recognize two or four synonymous codons. Several factors have been hypothesized to determine the nucleotide at the wobble site of a tRNA anticodon in mitochondrial genomes, such as the codon-anticodon adaptation hypothesis, the wobble versa...