REVIEW: Inorganic Polyphosphates and Exopolyphosphatases in Different Cell Compartments of Saccharomyces cerevisiae

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L. P. Lichko^*, T. V. Kulakovskaya, and I. S. Kulaev

Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; fax: (495) 956-3370; E-mail: alla@ibpm.pushchino.ru

^* To whom correspondence should be addressed.

Received June 27, 2006

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The cytosol, nuclei, vacuoles, and mitochondria of the yeast Saccharomyces cerevisiae possess inorganic polyphosphates (polyPs). PolyP levels, spectra of polyP chain lengths, and their dependence on the growth phase are distinguished in the mentioned compartments. Inactivation of the PPX1 gene has no effect on the polyP metabolism under cultivation of the yeast in medium with glucose and 5-7 mM P_i. Inactivation of the PPN1 gene results in elimination of the high-molecular-mass exopolyphosphatases (~120 to 830 kD) of the cytosol, nuclei, vacuoles, and mitochondria of S. cerevisiae suggesting that it is just PPN1 that encodes these enzymes. Expression of the low-molecular-mass exopolyphosphatase of ~45 kD encoded by the PPX1 gene decreases under PPN1 inactivation as well. While PPN1 inactivation has negligible effect on polyP levels, it results in increase in the long-chain polyPs in all the compartments under study.

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KEY WORDS: polyphosphate, exopolyphosphatase, cytosol, nuclei, vacuoles, mitochondria, Saccharomyces cerevisiae, PPX1 and PPN1 genes, growth phase

DOI: 10.1134/S0006297906110010

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