The effect of inactivation of the exo-and endopolyphosphatase genes PPX1 and PPN1 on the level of different polyphosphates in the yeast Saccharomyces cerevisiae

The inactivation of the PPX1 and PPN1 genes, which encode the major enzymes of polyphosphate degradation (exopolyphosphatase and endopolyphosphatase, respectively), was found to exert different effects on the content of different polyphosphates in the yeast Saccharomyces cerevisiae. The content of relatively low-molecular-weight acid-soluble polyphosphates in mutant yeast strains is inversely proportional to the exopolyphosphatase activity of the cytosol. At the same time, the mutation of these genes exerts no effect on salt-soluble polyphosphates. The content of high-molecular-weight alkali-soluble polyphosphates increases twofold in a mutant with inactivated genes of both exopolyphosphatase and endopolyphosphatase. The data obtained confirm the earlier suggestion that the metabolic pathways of particular polyphosphates in yeasts are different.