Do the divisome and elongasome share a common evolutionary past?

Szwedziak, Piotr; Löwe, Jan

doi:10.1016/j.mib.2013.09.003

Cited by 92 publications

(88 citation statements)

References 63 publications

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“…(ii) The common property of all firmicutes is the formation of a thick cell wall composed of many layers of peptidoglycan. It is well established that cell wall homeostasis is subject to intricate regulation (46,47), and c-di-AMP might add another level of complexity to this control. (iii) Indeed, weak accumulation of c-di-AMP can cause resistance to ␤-lactam antibiotics that target cell wall synthesis in B. subtilis and can bypass the requirement for lipoteichoic acid in S. aureus (6,16).…”

Section: Discussionmentioning

confidence: 99%

An Essential Poison: Synthesis and Degradation of Cyclic Di-AMP in Bacillus subtilis

et al. 2015

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Gram-positive bacteria synthesize the second messenger cyclic di-AMP (c-di-AMP) to control cell wall and potassium homeostasis and to secure the integrity of their DNA. In the firmicutes, c-di-AMP is essential for growth. The model organism Bacillus subtilis encodes three diadenylate cyclases and two potential phosphodiesterases to produce and degrade c-di-AMP, respectively. Among the three cyclases, CdaA is conserved in nearly all firmicutes, and this enzyme seems to be responsible for the c-di-AMP that is required for cell wall homeostasis. Here, we demonstrate that CdaA localizes to the membrane and forms a complex with the regulatory protein CdaR and the glucosamine-6-phosphate mutase GlmM. Interestingly, cdaA, cdaR, and glmM form a gene cluster that is conserved throughout the firmicutes. This conserved arrangement and the observed interaction between the three proteins suggest a functional relationship. Our data suggest that GlmM and GlmS are involved in the control of c-di-AMP synthesis. These enzymes convert glutamine and fructose-6-phosphate to glutamate and glucosamine-1-phosphate. c-di-AMP synthesis is enhanced if the cells are grown in the presence of glutamate compared to that in glutamine-grown cells. Thus, the quality of the nitrogen source is an important signal for c-di-AMP production. In the analysis of c-di-AMP-degrading phosphodiesterases, we observed that both phosphodiesterases, GdpP and PgpH (previously known as YqfF), contribute to the degradation of the second messenger. Accumulation of c-di-AMP in a gdpP pgpH double mutant is toxic for the cells, and the cells respond to this accumulation by inactivation of the diadenylate cyclase CdaA. IMPORTANCEBacteria use second messengers for signal transduction. Cyclic di-AMP (c-di-AMP) is the only second messenger known so far that is essential for a large group of bacteria. We have studied the regulation of c-di-AMP synthesis and the role of the phosphodiesterases that degrade this second messenger. c-di-AMP synthesis strongly depends on the nitrogen source: glutamategrown cells produce more c-di-AMP than glutamine-grown cells. The accumulation of c-di-AMP in a strain lacking both phosphodiesterases is toxic and results in inactivation of the diadenylate cyclase CdaA. Our results suggest that CdaA is the critical diadenylate cyclase that produces the c-di-AMP that is both essential and toxic upon accumulation. In order to process environmental information in the cell, many organisms are capable of synthesizing so-called second messengers. These small molecules are formed in response to primary signals and perceived by cellular targets. Bacteria often use specific nucleotides as second messengers. These nucleotides include cyclic mononucleotides, such as cyclic AMP (cAMP) and cyclic GMP (cGMP), as well as cyclic dinucleotides, such as cyclic di-AMP (c-di-AMP), cyclic di-GMP (c-di-GMP), and (p) ppGpp (1-3).The investigation of c-di-AMP-mediated signaling has recently attracted much attention (2). This molecule is formed by many bacteria a...

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Section: Discussionmentioning

confidence: 99%

An Essential Poison: Synthesis and Degradation of Cyclic Di-AMP in Bacillus subtilis

et al. 2015

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“…FtsA and MreB are both structural homologs of actin (70), and both have the ability to interact with FtsZ (71). Moreover, FtsA and MreB have been proposed to share an evolutionary origin that subsequently diverged to perform parallel functions within the divisome and the elongasome, respectively (72). It is therefore tempting to speculate that in S. pneumoniae, which compared to bacilli has a different and less sophisticated elongation scheme, a single actin-like protein, FtsA, could perform both roles, taking over the functions of MreB, as seems to occur in preseptal PG synthesis in E. coli (71,(73)(74)(75).…”

Section: Discussionmentioning

confidence: 99%

Roles of the Essential Protein FtsA in Cell Growth and Division in Streptococcus pneumoniae

et al. 2017

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Streptococcus pneumoniae is an ovoid-shaped Gram-positive bacterium that grows by carrying out peripheral and septal peptidoglycan (PG) synthesis, analogous to model bacilli, such as Escherichia coli and Bacillus subtilis. In the model bacilli, FtsZ and FtsA proteins assemble into a ring at midcell and are dedicated to septal PG synthesis but not peripheral PG synthesis; hence, inactivation of FtsZ or FtsA results in long filamentous cells unable to divide. Here, we demonstrate that FtsA and FtsZ colocalize at midcell in S. pneumoniae and that partial depletion of FtsA perturbs septum synthesis, resulting in elongated cells with multiple FtsZ rings that fail to complete septation. Unexpectedly, complete depletion of FtsA resulted in the delocalization of FtsZ rings and ultimately cell ballooning and lysis. In contrast, depletion or deletion of gpsB and sepF, which in B. subtilis are synthetically lethal with ftsA, resulted in enlarged and elongated cells with multiple FtsZ rings, with deletion of sepF mimicking partial depletion of FtsA. Notably, cell ballooning was not observed, consistent with later recruitment of these proteins to midcell after Z-ring assembly. The overproduction of FtsA stimulates septation and suppresses the cell division defects caused by the deletion of sepF and gpsB under some conditions, supporting the notion that FtsA shares overlapping functions with GpsB and SepF at later steps in the division process. Our results indicate that, in S. pneumoniae, both GpsB and SepF are involved in septal PG synthesis, whereas FtsA and FtsZ coordinate both peripheral and septal PG synthesis and are codependent for localization at midcell.IMPORTANCE Streptococcus pneumoniae (pneumococcus) is a clinically important human pathogen for which more therapies against unexploited essential targets, like cell growth and division proteins, are needed. Pneumococcus is an ovoid-shaped Gram-positive bacterium with cell growth and division properties that have important distinctions from those of rod-shaped bacteria. Gaining insights into these processes can thus provide valuable information to develop novel antimicrobials. Whereas rods use distinctly localized protein machines at different cellular locations to synthesize peripheral and septal peptidoglycans, we present evidence that S. pneumoniae organizes these two machines at a single location in the middle of dividing cells. Here, we focus on the properties of the actin-like protein FtsA as an essential orchestrator of peripheral and septal growth in this bacterium.KEYWORDS FtsA, Gram-positive cocci, Streptococcus pneumoniae, cell division

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“…We first examined the role of cell wall PG synthesis activity, which takes place in two modes during the cell cycle: initially along the lateral cell body and then predominantly septum-localized during constriction (89,90). Septal cell wall synthesis is directed by the divisome, and lateral cell wall synthesis is directed by the 'elongasome' (91). These two systems may compete with each other, because they share the same precursors (92,93) and/or coordinate with each other during both cell wall elongation and constriction (94)(95)(96)(97)(98).…”

Section: Constriction Initiation and Progress Does Not Require Z-ringmentioning

confidence: 99%

Defining the rate-limiting processes of bacterial cytokinesis

Coltharp

Buss

Plumer

et al. 2016

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

161

216

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Bacterial cytokinesis is accomplished by the essential ‘divisome’ machinery. The most widely conserved divisome component, FtsZ, is a tubulin homolog that polymerizes into the ‘FtsZ-ring’ (‘Z-ring’). Previous in vitro studies suggest that Z-ring contraction serves as a major constrictive force generator to limit the progression of cytokinesis. Here, we applied quantitative superresolution imaging to examine whether and how Z-ring contraction limits the rate of septum closure during cytokinesis in Escherichia coli cells. Surprisingly, septum closure rate was robust to substantial changes in all Z-ring properties proposed to be coupled to force generation: FtsZ’s GTPase activity, Z-ring density, and the timing of Z-ring assembly and disassembly. Instead, the rate was limited by the activity of an essential cell wall synthesis enzyme and further modulated by a physical divisome–chromosome coupling. These results challenge a Z-ring–centric view of bacterial cytokinesis and identify cell wall synthesis and chromosome segregation as limiting processes of cytokinesis.

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Do the divisome and elongasome share a common evolutionary past?

Cited by 92 publications

References 63 publications

An Essential Poison: Synthesis and Degradation of Cyclic Di-AMP in Bacillus subtilis

An Essential Poison: Synthesis and Degradation of Cyclic Di-AMP in Bacillus subtilis

Roles of the Essential Protein FtsA in Cell Growth and Division in Streptococcus pneumoniae

Defining the rate-limiting processes of bacterial cytokinesis

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