Phosphotransferase-dependent accumulation of (p)ppGpp in response to glutamine deprivation in Caulobacter crescentus

Ronneau, Séverin; Petit, Kenny; Bolle, Xavier De; Hallez, Régis

doi:10.1038/ncomms11423

Cited by 86 publications

(149 citation statements)

References 49 publications

Supporting

Mentioning

134

Contrasting

Unclassified

Order By: Relevance

“…Alarmones have been shown to induce the stringent response upon nitrogen starvation (29). It has also been shown that (p)ppGpp production can be stimulated by the phosphotransferase (PTS) system in order to respond to metabolic cues and control cell cycle progression and cell growth in Caulobacter crescentus (30). Furthermore, elevated synthesis of the (p)ppGpp alarmone can lead to a full bypass of the D,D-transpeptidase activity of penicillin binding proteins (PBPs) and to a broad spectrum of ␤-lactam resistances (31,32).…”

mentioning

confidence: 99%

Absence of ppGpp Leads to Increased Mobilization of Intermediately Accumulated Poly(3-Hydroxybutyrate) in Ralstonia eutropha H16

Juengert

Borisova

Mayer

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

In this study, we constructed a set of Ralstonia eutropha H16 strains with single, double, or triple deletions of the (p)ppGpp synthase/hydrolase (spoT1), (p)ppGpp synthase (spoT2), and/or polyhydroxybutyrate (PHB) depolymerase (phaZa1 or phaZa3) gene, and we determined the impact on the levels of (p)ppGpp and on accumulated PHB. Mutants with deletions of both the spoT1 and spoT2 genes were unable to synthesize detectable amounts of (p)ppGpp and accumulated only minor amounts of PHB, due to PhaZa1-mediated depolymerization of PHB. In contrast, unusually high levels of PHB were found in strains in which the (p)ppGpp concentration was increased by the overexpression of (p)ppGpp synthase (SpoT2) and the absence of (p)ppGpp hydrolase. Determination of (p)ppGpp levels in wild-type R. eutropha under different growth conditions and induction of the stringent response by amino acid analogs showed that the concentrations of (p)ppGpp during the growth phase determine the amount of PHB remaining in later growth phases by influencing the efficiency of the PHB mobilization system in stationary growth. The data reported for a previously constructed ΔspoT2 strain (C. J. Brigham, D. R. Speth, C. Rha, and A. J. Sinskey, Appl Environ Microbiol 78:8033-8044, 2012, https://doi.org/ 10.1128/AEM.01693-12) were identified as due to an experimental error in strain construction, and our results are in contrast to the previous indication that the spoT2 gene product is essential for PHB accumulation in R. eutropha. IMPORTANCE Polyhydroxybutyrate (PHB) is an important intracellular carbon and energy storage compound in many prokaryotes and helps cells survive periods of starvation and other stress conditions. Research activities in several laboratories over the past 3 decades have shown that both PHB synthase and PHB depolymerase are constitutively expressed in most PHB-accumulating bacteria, such as Ralstonia eutropha. This implies that PHB synthase and depolymerase activities must be well regulated in order to avoid a futile cycle of simultaneous PHB synthesis and PHB degradation (mobilization). Previous reports suggested that the stringent response in Rhizobium etli and R. eutropha is involved in the regulation of PHB metabolism. However, the levels of (p)ppGpp and the influence of those levels on PHB accumulation and PHB mobilization have not yet been determined for any PHB-accumulating species. In this study, we optimized a (p)ppGpp extraction procedure and a highperformance liquid chromatography-mass spectrometry (HPLC-MS)-based detection method for the quantification of (p)ppGpp in R. eutropha. This enabled us to study the relationship between the concentrations of (p)ppGpp and the accumulated levels of PHB in the wild type and in several constructed mutant strains. We show that overproduction of the alarmone (p)ppGpp correlated with reduced growth and mas-

show abstract

mentioning

confidence: 99%

Absence of ppGpp Leads to Increased Mobilization of Intermediately Accumulated Poly(3-Hydroxybutyrate) in Ralstonia eutropha H16

Juengert

Borisova

Mayer

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…In a subsequent study by the same group, the authors found that when intracellular pools of glutamine drop, the (p)ppGpp hydrolysis function of SpoT becomes inhibited by the phosphorylated form of enzyme IIA (EIIA) (part of the phosphotransferase system responsible for nitrogen uptake [PTS Ntr ]). This leads to (p)ppGpp accumulation, slowed growth, and an extended G 1 phase in a proportion of synchronized cells (103). In the gdhZ mutant, the glutamate that is unable to feed into the TCA cycle may conceivably be converted to glutamine by GlnA (glutamine synthetase), also generating the preferred carbon source of C. crescentus, ammonium, as a by-product (103).…”

Section: Udp-glucose and Ugtp (B Subtilis)mentioning

confidence: 99%

“…This leads to (p)ppGpp accumulation, slowed growth, and an extended G 1 phase in a proportion of synchronized cells (103). In the gdhZ mutant, the glutamate that is unable to feed into the TCA cycle may conceivably be converted to glutamine by GlnA (glutamine synthetase), also generating the preferred carbon source of C. crescentus, ammonium, as a by-product (103). However, the glnA gene is also repressed by high levels of glutamine (103), so the balance between glutamate and glutamine may be disrupted in the gdhZ mutant, leading to elevated (p)ppGpp levels.…”

Section: Udp-glucose and Ugtp (B Subtilis)mentioning

confidence: 99%

“…In the gdhZ mutant, the glutamate that is unable to feed into the TCA cycle may conceivably be converted to glutamine by GlnA (glutamine synthetase), also generating the preferred carbon source of C. crescentus, ammonium, as a by-product (103). However, the glnA gene is also repressed by high levels of glutamine (103), so the balance between glutamate and glutamine may be disrupted in the gdhZ mutant, leading to elevated (p)ppGpp levels. This scenario would also be consistent with the authors' observation that exogenous addition of glutamine did not rescue the observed cell division defects in the gdhZ mutant.…”

Section: Udp-glucose and Ugtp (B Subtilis)mentioning

confidence: 99%

See 1 more Smart Citation

Metabolism Shapes the Cell

Sperber

Herman

2017

J Bacteriol

View full text Add to dashboard Cite

More than 5 decades of work support the idea that cell envelope synthesis, including the inward growth of cell division, is tightly coordinated with DNA replication and protein synthesis through central metabolism. Remarkably, no unifying model exists to account for how these fundamentally disparate processes are functionally coupled. Recent studies demonstrate that proteins involved in carbohydrate and nitrogen metabolism can moonlight as direct regulators of cell division, coordinate cell division and DNA replication, and even suppress defects in DNA replication. In this minireview, we focus on studies illustrating the intimate link between metabolism and regulation of peptidoglycan (PG) synthesis during growth and division, and we identify the following three recurring themes. (i) Nutrient availability, not growth rate, is the primary determinant of cell size. (ii) The degree of gluconeogenic flux is likely to have a profound impact on the metabolites available for cell envelope synthesis, so growth medium selection is a critical consideration when designing and interpreting experiments related to morphogenesis. (iii) Perturbations in pathways relying on commonly shared and limiting metabolites, like undecaprenyl phosphate (Und-P), can lead to pleotropic phenotypes in unrelated pathways.KEYWORDS FtsZ, MreB, UDP-glucose, cell division, gluconeogenesis, metabolism, morphogenesis, peptidoglycan, phosphoenolpyruvate, undecaprenyl phosphate T o accurately partition chromosomes and other cell contents during reproduction, cells must possess mechanisms to organize repeated cycles of cell growth, chromosome replication, and division. Eukaryotes orchestrate this coordination using the cell cycle and separate growth, DNA synthesis, and cytokinesis into distinct, temporally sequestered phases. Bacteria, by contrast, simultaneously increase in cell size and replicate DNA before (or concurrently with) cell division. Elucidating the molecular mechanisms prokaryotes employ to achieve spatiotemporal organization of these intertwined yet functionally disparate processes is of considerable interest to scientists seeking to understand bacterial reproduction, and many outstanding questions remain to be answered. For example, how is DNA replication kept in sync with changing growth and division rates? How are cell dimensions maintained or actively rearranged in response to environmental or developmental cues? What signals do cells sense to switch between increasing in cell size and dividing during the cell cycle? Relatedly, how are these signals transduced to activate/deactivate the distinct machineries required for each process?Perhaps one of the biggest mysteries remaining in bacterial cell biology relates to understanding the regulatory cross talk that must occur to integrate central metabolism with macromolecular biosynthesis. Nutrients are converted into stored energy and precursors used to synthesize macromolecules like DNA and peptidoglycan (PG), so it is no surprise that nutrient availability has a profound impac...

show abstract

“…Chez l'α-protéobactérie Caulobacter crescentus, c'est la stabilité de la protéine DnaA qui est placée sous contrôle du (p)ppGpp (Figure 2). En effet, une carence nutritive active la synthèse de l'alarmone par l'unique (p)ppGpp synthétase SpoT [7][8][9], ce qui stimule, entre autres, la dégradation protéolytique de DnaA par une protéase et, de ce fait, empêche d'initier la réplication d'ADN [8,10]. À ce jour, nous ne savons pas comment le (p)ppGpp module la protéolyse de DnaA.…”

Section: Contrôle Métabolique De La Réplication D'adn Initiation De Lunclassified

Métabolisme et cycle cellulaire, deux processus interconnectés chez les bactéries

Hallez

2016

Med Sci (Paris)

Self Cite

View full text Add to dashboard Cite

Afin d’optimiser les chances de survie d’une cellule dans son environnement, le métabolisme et le cycle cellulaire doivent nécessairement être interconnectés. En effet, les cellules possèdent des mécanismes leur permettant, d’une part, de vérifier leur état métabolique avant d’initier l’une ou l’autre étape du cycle cellulaire souvent énergivore et, d’autre part, d’achever certaines étapes du cycle cellulaire avant d’éventuellement modifier leur métabolisme. Parce que les bactéries ne dérogent pas à cette règle, un nombre croissant d’exemples de connexions entre le métabolisme et le cycle cellulaire a émergé ces dernières années. L’identification d’enzymes métaboliques comme messagers coordonnant métabolisme et cycle cellulaire, permet d’ajouter une nouvelle dimension aux cartes métaboliques. La très grande conservation de ces mêmes cartes métaboliques, des bactéries jusqu’à l’homme, permet également d’imaginer des recherches sur les cellules tumorales qui ont un cycle cellulaire débridé et un appétit vorace.

show abstract

Phosphotransferase-dependent accumulation of (p)ppGpp in response to glutamine deprivation in Caulobacter crescentus

Cited by 86 publications

References 49 publications

Absence of ppGpp Leads to Increased Mobilization of Intermediately Accumulated Poly(3-Hydroxybutyrate) in Ralstonia eutropha H16

Absence of ppGpp Leads to Increased Mobilization of Intermediately Accumulated Poly(3-Hydroxybutyrate) in Ralstonia eutropha H16

Metabolism Shapes the Cell

Métabolisme et cycle cellulaire, deux processus interconnectés chez les bactéries

Contact Info

Product

Resources

About