In vivo levels of diadenosine tetraphosphate and adenosine tetraphospho-guanosine in Physarum polycephalum during the cell cycle and oxidative stress.

Garrison, Preston N.; Mathis, S. A.; Barnes, Larry D.

doi:10.1128/mcb.6.4.1179

Cited by 47 publications

(25 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reasons for this discrepancy are not quite clear, but it must be stressed that our determinations of ATP and Ap4A, for instance, are in good agreement with those reported in references 3 and 21. Our conclusions are further supported by the recent work of Garrison et al (11), who showed that no variation in the Ap4X level could be observed in the autosynchronous growth of Physarum polycephalum, in contrast to an earlier publication by Grummt and co-workers (31) According to all these data, as well as findings presented elsewhere (3, 9, 11), the concept of Ap4A as a trigger of the proliferative state of eucaryotic cells has to be seriously reexamined. We cannot, however, completely rule out participation of Ap4A in the tuning of the DNA synthesizing machinery, on the basis of in vitro experiments showing, first, that an Ap4A-binding activity is found tightly associated to DNA polymerase a (5,13,20,24,29,37).…”

Section: Discussionsupporting

confidence: 82%

“…It could be argued that our determinations, performed by the coupled luciferase-phosphodiesterase assay (18), in fact detect all dinucleoside polyphosphates (of general structure Ap,X, where X is any nucleoside and n is -4). It must be stressed, however, that Ap4A is the major component that contributes to the bioluminescence signal in cellular extracts, as shown by high-performance liquid chromatography (2,3,7,11), so that the values measured for Ap4X most likely reflect the level of Ap4A with a good accuracy.…”

Section: Discussionmentioning

confidence: 99%

“…Despite the striking convergence of all the above results, the working hypothesis that Ap4A plays an essential role in S-phase DNA replication was recently questioned (3,9,11).…”

Section: * Corresponding Authormentioning

confidence: 99%

See 2 more Smart Citations

Cell cycle variations of dinucleoside polyphosphates in synchronized cultures of mammalian cells.

Orfanoudakis¹,

Baltzinger²,

Meyer³

et al. 1987

Mol. Cell. Biol.

View full text Add to dashboard Cite

Zajdela hepatoma culture cells (ZHC) and mouse embryo fibroblasts (Swiss 3T3) were synchronized in G, or S phase by serum deprivation and aphidicolin treatment, respectively, to study the possible variations in adenylyl nucleotide (Ap4X) pool size during the progress of the cell cycle. Only minor variations, which never exceeded a factor of 2, were observed when the Ap4X concentrations were expressed on a cellular basis. The variations were found to be strictly parallel to the ATP variations. Upon release from an aphidicolin block, the minor variations of Ap4X followed DNA synthesis and preceded cytokinesis. When the nucleotide content was compared with the amount of proteins, the faint specffic cell cycle changes were almost completely damped when the cells were synchronized by serum deprivation, but remained practically unchanged in the case of aphidicolin synchronization. These results suggest that the observed variations could reflect the accumulation of some nucleotides before cell division. It is not clear yet whether the variation in Ap4X concentration is significant by itself or is simply a phenomenon resulting from changes in the ATP pool.Diadenosine 5',5' "-P1,P4-tetraphosphate (Ap4A) has been detected in almost all procaryotic and eucaryotic cells examined so far, with the possible exception of erythrocytes (10). Blood platelets, which are particularly rich in Ap4A (10), were recently shown to contain much lower amounts of this compound in Chediak-Higashi syndrome (16). This compound is produced in vitro and presumably in vivo by the back-reaction of an aminoacyl adenylate with ATP, catalyzed by some aminoacyl-tRNA synthetases (34; reviewed in reference 33).In the past few years, a collection of experimental data obtained with diverse eucaryotic systems has converged on the hypothesis that Ap4A could be a good candidate among the regulatory molecules implicated in cell growth and, more precisely, in DNA replicative machinery. This evidence can be summarized as follows: (i) intracellular levels of Ap4A were found to be inversely related to generation time, suggesting a role of Ap4A in the proliferative activity of the cell (23); (ii) the ability of Ap4A to stimulate DNA synthesis in resting permeabilized mammalian cells (12) or in Xenopus laevis oocytes injected together with DNA templates (36), and the observation of a higher number of replication forks in the DNA molecules of Ap4A-stimulated cells (12), indicated a metabolic role of Ap4A in the initiation of DNA synthesis; (iii) the binding of Ap4A to DNA polymerase a (5,13,20,24) reinforced this hypothesis by supporting a role of primer for Ap4A in in vitro DNA replication.In vivo support of the implication of Ap4A as an inducer of DNA synthesis in mammalian cells was provided by a report of specific cell cycle variations for this compound. A 1,000-fold increase of the intracellular level of Ap4A in baby hamster kidney fibroblasts and mouse 3T3 cells after mitogenic induction of the cells arrested in G1 phase was reported (30). Similarly, in the aut...

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Cell cycle variations of dinucleoside polyphosphates in synchronized cultures of mammalian cells.

Orfanoudakis¹,

Baltzinger²,

Meyer³

et al. 1987

Mol. Cell. Biol.

View full text Add to dashboard Cite

show abstract

“…dinucleoside polyphosphates (7). The dinucleoside polyphosphate Ap 4 A 1 is induced upon oxidative stress and heat shock both in prokaryotes and eukaryotes (8,9), and the Nudix enzyme subsequently degrades this signaling component to restore the intracellular balance. Experimental data indicate that an increased concentration of Ap 4 A is a signal for cell division in Escherichia coli (10).…”

mentioning

confidence: 99%

The NudA Protein in the Gastric Pathogen Helicobacter pylori Is an Ubiquitous and Constitutively Expressed Dinucleoside Polyphosphate Hydrolase

Lundin

Nilsson

Gerhard

et al. 2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

The gastric pathogen Helicobacter pylori harbors one Nudix hydrolase, NudA, that belongs to the nucleoside polyphosphate hydrolase subgroup. In this work, the enzymatic activity of purified recombinant NudA protein was analyzed on a number of nucleoside polyphosphates. This predicted 18.6-kDa protein preferably hydrolyzes diadenosine tetraphosphate, Ap 4 A at a k cat of 0.15 s ؊1 and a K m of 80 M, resulting in an asymmetrical cleavage of the molecule into ATP and AMP. To study the biological role of this enzyme in H. pylori, an insertion mutant was constructed. There was a 2-7-fold decrease in survival of the mutant as compared with the wild type after hydrogen peroxide exposure but no difference in survival after heat shock or in spontaneous mutation frequency. Western blot analyses revealed that NudA is constitutively expressed in H. pylori at different growth stages and during stress, which would indicate that this protein has a housekeeping function. Given that H. pylori is a diverse species and that all the H. pylori strains tested in this study harbor the nudA gene and show protein expression, we consider NudA to be an important enzyme in this bacterium.

show abstract

“…However, Bambara et al (5) have presented arguments against this putative function of Ap4A. The constancy of Ap4A during traverse of the cell cycle in Physarum polycephalum (16), E. coli (40), and cultured mammalian cells (35,38) also argues against the hypothesis that Ap4A is a positive regulator of DNA synthesis.…”

mentioning

confidence: 96%

Changes in diadenosine tetraphosphate levels in Physarum polycephalum with different oxygen concentrations

1989

Self Cite

View full text Add to dashboard Cite

Cellular levels of diadenosine tetraphosphate (Ap4A) were measured, by a specific high-pressure liquid chromatography method, in microplasmodia of Physarum polycephalum subjected to different degrees of hypoxia, hyperoxia, and treatment with H202. Ap,A levels increased three-to sevenfold under anaerobic conditions, and the microplasmodia remained viable after such treatment. Elevated levels of Ap4A returned to the basal level within 5 to 10 min upon reoxygenation of the microplasmodia. The increases in Ap4A levels were larger in stationary-phase or starved microplasmodia than in fed, log-phase microplasmodia. The maximal increase measured in log-phase microplasmodia was twofold. No significant changes in Ap4A levels occurred in microplasmodia subjected to mild hypoxia, hyperoxia, or treatment with 1 mM H202. These results indicate that in P. polycephalum, Ap4A may function in the metabolic response to anaerobic conditions rather than in the response to oxidative stress.

show abstract

In vivo levels of diadenosine tetraphosphate and adenosine tetraphospho-guanosine in Physarum polycephalum during the cell cycle and oxidative stress.

Cited by 47 publications

References 53 publications

Cell cycle variations of dinucleoside polyphosphates in synchronized cultures of mammalian cells.

Cell cycle variations of dinucleoside polyphosphates in synchronized cultures of mammalian cells.

The NudA Protein in the Gastric Pathogen Helicobacter pylori Is an Ubiquitous and Constitutively Expressed Dinucleoside Polyphosphate Hydrolase

Changes in diadenosine tetraphosphate levels in Physarum polycephalum with different oxygen concentrations

Contact Info

Product

Resources

About