Mitochondrial diseases: Yeast as a model for the study of suppressors

摘要

Mitochondrial (mt) tRNA gene mutations are an important cause of human morbidity and are associated with different syndromes. We have previously shown that the mitochondrial protein synthesis elongation factor EFTu and isolated sequences from the carboxy-terminal domain of yeast and human mt leucyl-tRNA synthetases (LeuRS), have a wide range of suppression capability among different yeast mt tRNA mutants having defective respiratory phenotype. Here we show that the rescuing capability can be restricted to a specific sequence of six amino acids from the carboxy-terminal domain of mt LeuRS. On the other hand by overexpressing a mutated version of mt EF-Tu in a yeast strain deleted for the endogenous nuclear gene we identified the specific region involved in suppression.