Polyphosphatase PPN1 of Saccharomyces cerevisiae: Switching of Exopolyphosphatase and Endopolyphosphatase Activities

Abstract

The polyphosphatase PPN1 of Saccharomyces cerevisiae shows an exopolyphosphatase activity splitting phosphate from chain end and an endopolyphosphatase activity fragmenting high molecular inorganic polyphosphates into shorter polymers. We revealed the compounds switching these activities of PPN1. Phosphate release and fragmentation of high molecular polyphosphate prevailed in the presence of Co2+ and Mg2+, respectively. Phosphate release and polyphosphate chain shortening in the presence of Co2+ were inhibited by ADP but not affected by ATP and argininе. The polyphosphate chain shortening in the presence of Mg2+ was activated by ADP and arginine but inhibited by ATP.

Polyphosphatase PPX1 of <i>Saccharomyces cerevisiae</i> as a Tool for Polyphosphate Assay

“…The most high-molecular weight polyP was not hydrolyzed even after 120-min incubation. Thus, the recombinant PPX1 had no endopolyphosphatase activity, in contrast to PPN1 [33].…”

“…The yeast polyphosphatase PPN1 is inhibited by ATP and stimulated by ADP [33]. The effects of AMP, ADP and ATP on the activity of the recombinant PPX1 with polyP 15 as a substrate were insignificant ( Table 3).…”

Enzymes of yeast polyphosphate metabolism: structure, enzymology and biological roles

“…Reaction end products are P i and P 3 , whereas PP i is a potent inhibitor [42]. A recent study has revealed that, depending on the reaction conditions, Ppn1 acts preferentially as endo-or exopolyphosphatase and its endopolyphosphatase activity is inhibited by ATP, but activated by ADP [43].…”

Polyphosphatase PPN1 of <i>Saccharomyces cerevisiae</i> Is a Deoxyadenosine Triphosphate Phosphohydrolase

“…The exopolyphosphatase PPX1 of S. cerevisiae hydrolyzes adenosine-tetraphosphate phosphohydrolase and guanosine-tetraphosphate phosphorhydrolase activities [14]. The polyphosphatase PPN1 (http://www.uniprot.org/uniprot/Q04119) of S. cerevisiae degrades PolyP both by cleaving Pi from the chain end and by fragmenting long-chain polymers into shorter ones [15] [16]. Pi release was predominant in the presence of Co 2+ , while the fragmentation of high-molecular PolyP was predominant in the presence of Mg 2+ [16].…”

“…The polyphosphatase PPN1 (http://www.uniprot.org/uniprot/Q04119) of S. cerevisiae degrades PolyP both by cleaving Pi from the chain end and by fragmenting long-chain polymers into shorter ones [15] [16]. Pi release was predominant in the presence of Co 2+ , while the fragmentation of high-molecular PolyP was predominant in the presence of Mg 2+ [16]. No other substrates of this enzyme are known; the pyrophosphatase activity of PPN1 was extremely low [17].…”