title: Mitochondrial translation: elongation factor tu is essential in fission yeast and depends on an exchange factor conserved in humans but not in budding yeast.
abstract: The translation elongation factor EF-Tu is a GTPase that delivers amino-acylated tRNAs to the ribosome during the elongation step of translation. EF-Tu/GDP is recycled by the guanine nucleotide exchange factor EF-Ts. Whereas EF-Ts is lacking in S. cerevisiae, both translation factors are found in S. pombe and H. sapiens mitochondria, consistent with the known similarity between fission yeast and human cell mitochondrial physiology. We constructed yeast mutants lacking these elongation factors. We show that mitochondrial translation is vital for S. pombe, as it is for human cells. In a genetic background allowing the loss of mitochondrial functions, a block in mitochondrial translation in S. pombe leads to a major depletion of mtDNA. The relationships between EF-Ts and EF-Tu from both yeasts and humans were investigated through functional complementation and coexpression experiments and by a search for suppressors of the absence of the S. pombe EF-Ts. We find that S. cerevisiae EF-Tu is functionally equivalent to the S. pombe EF-Tu/EF-Ts couple. Point mutations in the S. pombe EF-Tu can render it independent of its exchange factor, thereby mimicking the situation in S. cerevisiae.
authors.affiliation: Centre de Génétique Moléculaire du CNRS, Gif-sur-Yvette, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Chiron
authors.forename: Audrey
authors.initials: A
authors.lastname: Suleau
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bonnefoy
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics; D017353:Gene Deletion; D005816:Genetic Complementation Test; D005821:Genetic Techniques; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010101:Oxygen Consumption; D010444:Peptide Elongation Factor Tu / Q000502:physiology*; D010641:Phenotype; D017354:Point Mutation; D011485:Protein Binding; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D012568:Schizosaccharomyces / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014158:Transcription, Genetic
chemical_list: D004272:DNA, Mitochondrial; D010444:Peptide Elongation Factor Tu; D005947:Glucose