In plants, as in most eukaryotic cells, import of nuclear-encoded cytosolic tRNAs is an essential process for mitochondrial biogenesis. Despite its broad occurrence, the mechanisms governing RNA transport into mitochondria are far less understood than protein import. This article demonstrates by Northwestern and gel-shift experiments that the plant mitochondrial voltage-dependent anion channel ...

A number of human diseases are caused by inherited mitochondrial DNA mutations. Two of these diseases, MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes) and MERRF (myoclonic epilepsy and ragged-red fibres), are commonly caused by point mutations to tRNA genes encoded by mitochondrial DNA. Here we report on how these mutations affect mitochondrial function ...

Bovine mitochondrial tRNA(Ser) (UCN) has been thought to have two U-U mismatches at the top of the acceptor stem, as inferred from its gene sequence. However, this unusual structure has not been confirmed at the RNA level. In the course of investigating the structure and function of mitochondrial tRNAs, we have isolated the bovine liver mitochondrial tRNA(Ser) (UCN) and determined its complete ...

Human Mitochondrial Leucyl-tRNA Synthetase Corrects Mitochondrial Dysfunctions Due to the tRNA A3243G Mutation, Associated with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Symptoms and Diabetes Ronghua Li and Min-Xin Guan* Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, and Department of Pediatrics, University of Cincinnati Coll...

Although mitochondrial import of nuclear DNA-encoded RNAs is widely occurring, their functions in the organelles are not always understood. Mitochondrial function(s) of tRNA(Lys)(CUU), tRK1, targeted into Saccharomyces cerevisiae mitochondria was mysterious, since mitochondrial DNA-encoded tRNA(Lys)(UUU), tRK3, was hypothesized to decode both lysine codons, AAA and AAG. Mitochondrial targeting ...

Import of tRNA into the mitochondrial matrix of Trypanosoma brucei was reconstituted in vitro. Efficient import required the hydrolysis of externally added ATP and was shown to be a carrier-mediated process depending on proteinaceous receptors on the surface of mitochondria. A partly synthetic tRNA(Tyr) as well as a physiological tRNA(Lys) were imported along the same pathway. Contrary to impor...

The proper function of mammalian mitochondria necessitates a coordinated expression of both nuclear and mitochondrial genes, most likely due to the co-evolution of nuclear and mitochondrial genomes. The non-protein coding regions of mitochondrial DNA (mtDNA) including the D-loop, tRNA and rRNA genes form a major component of this regulated expression unit. Here we present comparative analyses o...

the aim of current study was to investigate the nucleotide sequence of seven trna genes in mitochondrial gene of khorasan’s native chicken and identification of possible mutations in it. for performing it, this part of the gene was cloned using the specific amplification initiators and cloned in the plasmid ptg19-t vector in dh5α strain of e-coli after the sampling and extracting the dna from w...

We have studied mitochondrial gene expression and metabolic function in a human lymphoblastoid cell-line homoplasmic for the np 7445, deafness-associated mitochondrial DNA mutation. The mutation maps to the 3' termini of the oppositely oriented genes encoding cytochrome oxidase subunit I (COI) and tRNA-ser(UCN). In comparison with control lymphoblastoid cells, we detected a marked depletion (> ...

Transfer RNAs are ancient molecules whose origin goes back to the beginning of life on earth. As key partners in the ribosome-translation machinery, tRNAs read genetic information on messenger RNA and deliver codon specific amino acids for peptide bond synthesis to the ribosome. They are present in all types of cells as well as in organelles. Animal mitochondria tRNAs show a low level of primar...