The ?polyphosphate overplus? phenomenon in myxococcus xanthus and its influence on the architecture of the cell

Voelz, Herbert; Voelz, Ursula; Ortigoza, Raoul O.

doi:10.1007/bf00409874

Cited by 56 publications

(28 citation statements)

References 34 publications

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“…In the experimental procedures employed here, however, we could not estimate the saturation level of RNA polymerase binding to poly P chains. The concentration of poly P used in this study is close to that found in the in vivo in stationary phase Myxobacteria cells (Voeltz et al 1966). Therefore, the intracellular concentration of poly P in the stationary phase cells is evidently sufficient for the modification of core RNA polymerase.…”

Section: Discussionsupporting

confidence: 81%

Functional interaction of Escherichia coli RNA polymerase with inorganic polyphosphate

Kusano

Ishihama

1997

Genes to Cells

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Section: Discussionsupporting

confidence: 81%

Functional interaction of Escherichia coli RNA polymerase with inorganic polyphosphate

Kusano

Ishihama

1997

Genes to Cells

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“…PolyP accumulation in response to nutrient deprivation has also been observed in many other microorganisms, including Pseudomonas aeruginosa, Klebsiella aerogenes, (A.K. and H.O., unpublished data), and Myxococcus xanthus (7). Important signals for nutritional stress responses in E. coli are guanosine 5Ј-triphosphate 3Ј-diphosphate (pppGpp) and guanosine 5Ј-diphosphate 3Ј-diphosphate (ppGpp), which accumulate in response to nutrient deficiencies as well as to undefined factors that operate during starvation and initiation of the stationary phase (8).…”

mentioning

confidence: 63%

Inorganic polyphosphate kinase is required to stimulate protein degradation and for adaptation to amino acid starvation in Escherichia coli

Kuroda

Tanaka²,

Ikeda³

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

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Inorganic polyphosphate (polyP) kinase was studied for its roles in physiological responses to nutritional deprivation in Escherichia coli. A mutant lacking polyP kinase exhibited an extended lag phase of growth, when shifted from a rich to a minimal medium (nutritional downshift). Supplementation of amino acids to the minimal medium abolished the extended growth lag of the mutant. Levels of the stringent response factor, guanosine 5-diphosphate 3-diphosphate, increased in response to the nutritional downshift, but, unlike in the wild type, the levels were sustained in the mutant. These results suggested that the mutant was impaired in the induction of amino acid biosynthetic enzymes. The expression of an amino acid biosynthetic gene, hisG, was examined by using a transcriptional lacZ fusion. Although the mutant did not express the fusion in response to the nutritional downshift, Northern blot analysis revealed a significant increase of hisG-lacZ mRNA. Amino acids generated by intracellular protein degradation are very important for the synthesis of enzymes at the onset of starvation. In the wild type, the rate of protein degradation increased in response to the nutritional downshift whereas it did not in the mutant. Supplementation of amino acids at low concentrations to the minimal medium enabled the mutant to express the hisG-lacZ fusion. Thus, the impaired regulation of protein degradation results in the adaptation defect, suggesting that polyP kinase is required to stimulate protein degradation.

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“…However, the glucokinase of P. shermanii, which utilizes polyP to phosphorylate glucose, is a homodimer of 33-kDa subunits (17) by either processive (polyP 700 ) or nonprocessive (polyP 30 ) mechanisms (18). In M. tuberculosis, polyP glucokinase utilizes the longchain polyP nonprocessively by an ordered Bi-Bi mechanism (13).…”

Section: Effects Of Chemical Agents On Ppk Activities-ementioning

confidence: 99%

“…In yeast, ppppG can be generated by phosphoglycerate kinase (24) and digested by an exopolyphosphatase (25); ppppG can also stimulate mammalian adenylate cyclase (26). However, unlike ppGpp for which regulatory roles are established (27)(28)(29)(30), the cellular presence of ppppG and its functions are unknown.…”

Section: Effects Of Chemical Agents On Ppk Activities-ementioning

confidence: 99%

The Multiple Activities of Polyphosphate Kinase ofEscherichia coli and Their Subunit Structure Determined by Radiation Target Analysis

Tzeng

Kornberg

2000

Journal of Biological Chemistry

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) at low ATP concentrations. Thus, the diverse functions of this enzyme involve different subunit organizations and conformations. The highly conserved homology of PPK among 18 microorganisms was used to determine important residues and conserved regions by alanine substitution, by site-directed mutagenesis, and by deletion mutagenesis. Of 46 single-site mutants, seven exhibit none of the five enzymatic activities; in one mutant, ATP synthesis from polyP is reduced relative to GTP synthesis. Among deletion mutants, some lost all five PPK activities, but others retained partial activity for some reactions but not for others.

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The ?polyphosphate overplus? phenomenon in myxococcus xanthus and its influence on the architecture of the cell

Cited by 56 publications

References 34 publications

Functional interaction of Escherichia coli RNA polymerase with inorganic polyphosphate

Functional interaction of Escherichia coli RNA polymerase with inorganic polyphosphate

Inorganic polyphosphate kinase is required to stimulate protein degradation and for adaptation to amino acid starvation in Escherichia coli

The Multiple Activities of Polyphosphate Kinase ofEscherichia coli and Their Subunit Structure Determined by Radiation Target Analysis

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