Effect of PPX1 inactivation on exopolyphosphatases of different cell compartments of the yeast Saccharomyces cerevisiae

Inactivation of PPX1 encoding a major exopolyphosphatase (PPX1) in Saccharomyces cerevisiae results in a change of exopolyphosphatase spectra in the yeast cells. In the PPX1-deficient strain, an elimination of similar to 45 kDa enzyme is observed in cytosol and cell envelopes, and the activity of an exopolyphosphatase with a molecular mass of similar to 830 kDa increases 5-fold in the cytosol. These two enzyme activities differ greatly from each other not only in molecular masses but also in biochemical properties, Inactivation of PPX1 does not result in any changes in the content and properties of vacuolar exopolyphosphatase as compared with the wild strain of S. cerevisiae. In response to PPX1 mutation, exopolyphosphatase properties in the cell as a whole undergo modifications including the ability to hydrolyze polyphosphates with different lengths of the chain. (C) 2002 Elsevier Science B.V. All rights reserved.