ИСТИНА

Protein FRET-sensors of the ATeam family enable monitoring of ATP concentration in yeast in vivo. Here we used ATeam sensors to study the changes of mitochondrial and cytosolic ATP concentrations of Saccharomyces cerevisiae yeast cells under normal and mitochondrial dysfunction conditions. We found that activation of glycolysis leads to an increase in the level of ATP in the mitochondrial matrix, but not in the cytoplasm. In contrast, in yeast cells lacking mitochondrial DNA and, therefore, incapable of oxidative phosphorylation, supplementation of glycolysis induced a temporary decrease and then increase of ATP concentration in cytoplasm. Furthermore, the addition of protonophores which dissipate transmembrane potential across cellular membranes caused a temporary decrease in the level of ATP in the cytoplasm, but not in the mitochondrial matrix of wild type cells. This effect required active ATP/ADP exchange between the cytoplasm and mitochondria. When the ATP/ADP exchanger gene was repressed, protonophores did not cause a drop in cytoplasmic ATP, and activation of glycolysis resulted in an increase in the cytoplasmic ATP, but the mitochondrial ATP level remained unchanged. We conclude that mitochondria make a significant contribution to maintaining constant ATP concentration in the cytoplasm of S. cerevisiae. This study was funded by the Russian Scientific Foundation (Grant No. 20-14-00268).