Mutations in mitochondrial DNA (mtDNA) tRNA genes can be considered functionally recessive because they result in a clinical or biochemical phenotype only when the percentage of mutant molecules exceeds a critical threshold value, in the range of 70-90%. We report a novel mtDNA mutation that contradicts this rule, since it caused a severe multisystem disorder and respiratory chain (RC) deficien...

An A to G transition at nucleotide 3,243 in the tRNA(Leu)(UUR) gene of mitochondrial DNA has recently been identified as a pathogenic point mutation which is associated with diabetes mellitus and sensorineural deafness in several pedigrees. We have also reported a family showing the association of deafness and diabetes mellitus as the predominant clinical features with this mutation. Audiologic...

Mitochondrial DNA (mtDNA) mutations are an important cause of human disease for which there is no efficient treatment. Our aim was to determine whether the A8344G mitochondrial tRNA(Lys) mutation, which can cause the MERRF (myoclonic epilepsy with ragged-red fibers) syndrome, could be complemented by targeting tRNAs into mitochondria from the cytosol. Import of small RNAs into mitochondria has ...

Sensory ataxic neuropathy (SAN) is a recently identified neurological disorder in golden retrievers. Pedigree analysis revealed that all affected dogs belong to one maternal lineage, and a statistical analysis showed that the disorder has a mitochondrial origin. A one base pair deletion in the mitochondrial tRNA(Tyr) gene was identified at position 5304 in affected dogs after re-sequencing the ...

It was recently reported that Duchenne muscular dystrophy (DMD) patients and mdx mice have elevated levels of caveolin-3 expression in their skeletal muscles. However, it remains unknown whether this increased caveolin-3 levels contribute to the pathogenesis of DMD. Also mitochondrial DNA mutation in the tRNA methionin (tRNA Met) gene has been shown to be associated with muscle weakness, severe...

Background: Pregnancy is the process from the fertilized ovum to the fetus with capability of extra uterine survival. Pregnancy loss is the most common complication of pregnancies. Advances in the detection of early pregnancy revealed that about 70% of human conceptions fail to achieve viability but clinically recognized pregnancies terminate as a miscarriage in about 15% of cases. About 1 in 3...

It was recently reported that Duchenne muscular dystrophy (DMD) patients and mdx mice have elevated levels of caveolin-3 expression in their skeletal muscles. However, it remains unknown whether this increased caveolin-3 levels contribute to the pathogenesis of DMD. Also mitochondrial DNA mutation in the tRNA methionin (tRNA Met) gene has been shown to be associated with muscle weakness, severe...

A 27-year-old woman with short stature, sensorineural deafness, and renal dysfunction was hospitalized for evaluation. The serum lactate and pyruvate concentrations were elevated. The analysis of her mitochondrial DNA revealed an A-to-G mutation of the tRNA(Leu (UUR)) gene at the 3243 position. Renal biopsy revealed many sclerotic glomeruli, advanced tubulointerstitial changes, and numerous swo...

Recognition sites of bovine mitochondrial serine tRNA specific for condons AGY [tRNA(Ser) (AGY)] by the cognate mitochondrial seryl-tRNA synthetase were studied using a range of tRNA(Ser)(AGY) variants which were obtained by the in vitro transcription of synthetic tRNA genes with T7 RNA polymerase. Base replacements in the anticodon and discriminator sites did not affect serine acceptance. Howe...