Missä polyfosfaattiketjut piilevät? Hiivan tumasta esimerkki

Inositolipolyfosfaatit ovat niin  selkeäkudoksinenverkosto sytosolissa että  fosfaattien  suuren nopeuden käsitely mitä esim  RNA ja DNA synteesit vaativat, ei todennäkösiesti toimi inositolifosfaatien  donoritoiminnalla. Jokin toinen tie  on olemassa. Etsin näitä polyfosfaattiketjuja tumanpuolelta. replikaatiolle saatavilla olevien  tarvittavien fosfaattien uuri imäärä on ollut joskus pohdintani kohde. Miten ne ovat järjestäytyneet että ne ovat siinä  heti paikan päällä. Ketjumainen  varallaolo tilanteen esiintymä on  tietysti järkevä. Mutta löydän tällaisen artikkelin: HIIVA-solusta.
http://www.ncbi.nlm.nih.gov/pubmed/16862600

Yeast. 2006 Jul 30;23(10):735-40.

Inorganic polyphosphate and exopolyphosphatase in the nuclei of Saccharomyces cerevisiae: dependence on the growth phase and inactivation of the PPX1 and PPN1 genes.

Lichko LP¹, Kulakovskaya TV, Kulaev IS.

Abstract

Nuclei of the yeast Saccharomyces cerevisiae possess inorganic polyphosphates (polyP) with chain lengths of ca. 10-200 phosphate residues. Subfractionation of the nuclei reveals that the most part of polyP is not associated with DNA. Transition of the yeast cells from stationary phase to active growth at orthophosphate (P(i)) excess in the medium is followed by the synthesis of the shortest polyP (<15 and="" high-molecular="" hydrolysis="" of="" phosphate="" polyp="" residues="" the="">45 phosphate residues) in the nuclei. Nuclear exopolyphosphatase (exopolyPase) activity does not depend on the growth phase. The PPX1 gene encoding the major cytosolic exopolyPase does not encode the nuclear one and its inactivation has no effect on polyP metabolism in this compartment. Under inactivation of the PPN1 gene encoding another yeast exopolyPase, elimination of the nuclear exopolyPase is observed. The effect of PPN1 inactivation on the polyP level in the nuclei is insignificant in the stationary phase, while in the exponential phase this level increases 2.3-fold as compared with the parent strain of S. cerevisiae. In the active growth phase, no hydrolysis of high-molecular polyP is detected while the synthesis of short-chain polyP is retained. The data obtained indicate substantial changes in polyP metabolism in nuclei under the renewal of active growth, which only partially depends on the genes of polyP metabolism known to date.
Copyright (c) 2006 John Wiley & Sons, Ltd.

PMID:

16862600

DOI:

10.1002/yea.1391

[PubMed - indexed for MEDLINE]

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