Exopolyphosphatases of the yeast

Lichko, L. P.; Andreeva, N. A.; Kulakovskaya, T. V.; Kulaev, I. S.

doi:10.1016/s1567-1356(02)00205-2

Cited by 38 publications

(37 citation statements)

References 32 publications

(50 reference statements)

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“…The labeling of rounded structures inside the nucleus decreased slightly after treatment with yeast exopolyphosphatase (scPPX1) (Online Supplementary Figure S3). The enzyme scPPX1 can be inhibited by negative-charged polymers, such as heparin 27 or RNA (results not shown). We, therefore, tested DAPI labeling of polyP in U266 permeabilized cells after treatment with scPPX1 and RNAase (Online Supplementary Figure S3).…”

Section: Polyphosphate Is Present In Myeloma Cell Linesmentioning

confidence: 97%

Myeloma cells contain high levels of inorganic polyphosphate which is associated with nucleolar transcription

Jimenez-Nuñez¹,

Moreno-Sanchez²,

Hernández-Ruiz³

et al. 2012

Haematologica

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The online version of this article has a Supplementary Appendix. BackgroundIn hematology there has recently been increasing interest in inorganic polyphosphate. This polymer accumulates in platelet granules and its functions include modulating various stages of blood coagulation, inducing angiogenesis, and provoking apoptosis of plasma cells. In this study we evaluated the characteristics of intracellular polyphosphate in myeloma cell lines, in primary myeloma cells from patients, and in other human B-cell populations from healthy donors. Design and MethodsWe have developed a novel flow cytometric method for detecting levels of polyphosphate in cell populations. We also used confocal microscopy and enzymatic analysis to study polyphosphate localization and characteristics. ResultsWe found that myeloma plasma cells contain higher levels of intracellular polyphosphate than normal plasma cells and other B-cell populations. Localization experiments indicated that high levels of polyphosphate accumulate in the nucleolus of myeloma cells. As the principal function of the nucleolus involves transcription of ribosomal DNA genes, we found changes in the cellular distribution of polyphosphate after the inhibition of nucleolar transcription. In addition, we found that RNA polymerase I activity, responsible for transcription in the nucleolus, is also modulated by polyphosphate, in a dose-dependent manner. ConclusionsOur results show an unusually high accumulation of polyphosphate in the nucleoli of myeloma cells and a functional relationship of this polymer with nucleolar transcription. Haematologica 2012;97(8):1264-1271. doi:10.3324/haematol.2011 This is an open-access paper. Myeloma cells contain high levels of inorganic polyphosphate which is associated with nucleolar transcription ABSTRACT© F e r r a t a S t o r t i F o u n d a t i o n

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Section: Polyphosphate Is Present In Myeloma Cell Linesmentioning

confidence: 97%

Myeloma cells contain high levels of inorganic polyphosphate which is associated with nucleolar transcription

Jimenez-Nuñez¹,

Moreno-Sanchez²,

Hernández-Ruiz³

et al. 2012

Haematologica

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“…Exopolyphosphatase from Escherichia coli requires divalent cations and K + for maximum activity, while exopolyphosphatase from yeast only requires divalent cations (Lichko et al, 2003). Membrane mitochondrial exopolyphosphatase activity from the hard tick R. microplus was found to be stimulated by Mg 2+ and was insensitive to K + .…”

Section: A Mitochondrial Membrane Exopolyphosphatasementioning

confidence: 96%

Role of Inorganic Polyphosphate in the Energy Metabolism of Ticks

Campos¹,

Façanha²,

Moraes³

et al. 2012

Bioenergetics

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“…Interestingly, yeast and A. aeolicus PPXs are monomeric proteins (15, 18 -20), whereas E. coli PPX is dimeric (10,16). 4 Interestingly, the yeast cell contains up to five different exopolyphosphatases in different compartments (22).…”

Section: Hismentioning

confidence: 99%

Kinetic and Mutational Analyses of the Major Cytosolic Exopolyphosphatase from Saccharomyces cerevisiae

Tammenkoski

Moiseev

Lahti

et al. 2007

Journal of Biological Chemistry

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Yeast exopolyphosphatase (scPPX) processively splits off the terminal phosphate group from linear polyphosphates longer than pyrophosphate. scPPX belongs to the DHH phosphoesterase superfamily and is evolutionarily close to the well characterized family II pyrophosphatase (PPase -bound enzyme. These results provide an initial step toward understanding the dynamics of scPPX catalysis and reveal significant functional differences between structurally similar scPPX and family II PPase. Linear inorganic polyphosphates (polyP)3 comprising chains of tens to hundreds of phosphate units are conserved in all cells, and thus are possible agents of evolution from prebiotic times (1, 2). In eukaryotes, they account for up to 20% of dry cell weight (1, 2). Recent evidence indicates that rather than simply being a store of phosphate and energy, polyP are required for bacterial responses to a variety of stress and stringency conditions, as well as for virulence of some pathogens (3-5). PolyP are additionally involved in blood clotting (6) and proliferation of mammary cancer cells (7).PolyP are synthesized by polyphosphate kinase, and hydrolyzed by exo-and endopolyphosphatases. Exopolyphosphatase (PPX) processively releases the terminal phosphate groups from polyP formed by Ն3 phosphate residues. Based on the primary structure, PPXs are classified into two types, whose prototypes are PPXs from yeast (Saccharomyces cerevisiae) cytosol and Escherichia coli. Yeast-type PPX, reported in fungi and protozoa, belongs to the superfamily of DHH phosphoesterases (named after the conserved Asp-His-His motif) (8), whereas E. coli-type PPX is present in Eubacteria and Archaea and belongs to a sugar kinase/actin/hsp-70 superfamily (9). Genes of both yeast-type PPXs (from S. cerevisiae and Leishmania major) and E. coli type PPXs (from E. coli, Aquifex aeolicus and Sulfolobus solfataricus) have been expressed in E. coli (10 -14), and the structures of S. cerevisiae (15), E. coli (16), 4 and A. aeolicus (E. coli type) (18) PPXs have been determined. The overall folds of the two PPX families are dissimilar. Specifically, the subunits comprise two domains in yeast-type PPX and four domains in E. coli-type PPX. However, in both families, the active site is located between the domains connected by a flexible linker. Interestingly, yeast and A. aeolicus PPXs are monomeric proteins (15, 18 -20), whereas E. coli PPX is dimeric (10, 16). 4 Interestingly, the yeast cell contains up to five different exopolyphosphatases in different compartments (22).The overall structure of yeast cytosolic PPX (scPPX) bears a striking similarity to that of the well characterized family II pyrophosphatase (PPase) (23, 24), a DHH phosphoesterase that catalyzes a similar reaction with pyrophosphate, the shortest polyphosphate. Despite only 12-17% sequence identity, 11 of the total 14 polar residues in the active site of family II PPase are conserved in all yeast-type PPXs, and two more are conserved in most of the enzymes (Fig. 1A), implying an evolutionary relationship. M...

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Exopolyphosphatases of the yeast

Cited by 38 publications

References 32 publications

Myeloma cells contain high levels of inorganic polyphosphate which is associated with nucleolar transcription

Myeloma cells contain high levels of inorganic polyphosphate which is associated with nucleolar transcription

Role of Inorganic Polyphosphate in the Energy Metabolism of Ticks

Kinetic and Mutational Analyses of the Major Cytosolic Exopolyphosphatase from Saccharomyces cerevisiae

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