ИСТИНА

Translation in mitochondria is finely tuned to provide the efficient and correct assembly of OXPHOS complexes and supercomplexes. In baking yeasts, Saccharomyces cerevisiae, only 8 proteins are synthesized in mitochondria, and their synthesis is regulated by complex system of translational factors and translational activators. Recently we have identified previously unknown yeast mitochondrial third translation initiation factor, Aim23p. The deletion of its gene leads to imbalance in mitochondrially encoded proteins translation, and phenotypically is manifested in the lag of yeasts growth on non-fermentable carbon sources, i.e, the lag-phase is not absent in yeasts growth but is significantly delayed. In current study we decided to explore the mechanism of yeast adaptation to the mitochondrial translation imbalance. By the measurement of cell respiration, complex IV and V activities, and supercomplex formation we have clearly shown that adaptation is independent on restoration of mitochondrial function. Nevertheless, with differential proteomics technique we have found that adaptation could be linked with hyperexpression of Tma19p protein, which prevents mitochondrial degradation and apoptosis.