DNA and origin region segregation are not affected by the transition from rod to sphere after inhibition of <i>Escherichia coli</i> MreB by A22

Karczmarek, Aneta; Martínez-Arteaga, Rocío; Alexeeva, Svetlana; Hansen, Flemming; Vicente, Miguel; Nanninga, N.; Blaauwen, T. den

doi:10.1111/j.1365-2958.2007.05855.x

Cited by 41 publications

(63 citation statements)

References 2 publications

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“…Furthermore, these same authors noted that cells expressing a mutant MreB protein failed to segregate their chromosomes normally (32). However, it has also been reported that A22 does not prevent chromosome segregation in E. coli (29). In an attempt to address this inconsistency, we used A22 to study the effect of MreB dynamics on origin segregation in our strain and under our experimental conditions.…”

Section: Vol 192 2010 E Coli Origin Segregation 6147mentioning

confidence: 90%

“…Several studies have demonstrated that inhibition of MreB polymerization does not perturb initiation and progression of DNA synthesis but does apparently block segregation of newly replicated origins, but not bulk DNA (20,31). Nevertheless, since MreB can serve as a cytoskeletal track for other proteins, its apparent role in origin segregation could be indirect, as supported by a reexamination of the role of MreB in E. coli DNA segregation (29).…”

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confidence: 99%

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Independent Segregation of the Two Arms of theEscherichia coli oriRegion Requires neither RNA Synthesis nor MreB Dynamics

Wang

Sherratt

2010

J Bacteriol

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The mechanism of Escherichia coli chromosome segregation remains elusive. We present results on the simultaneous tracking of segregation of multiple loci in the ori region of the chromosome in cells growing under conditions in which a single round of replication is initiated and completed in the same generation. Loci segregated as expected for progressive replication-segregation from oriC, with markers placed symmetrically on either side of oriC segregating to opposite cell halves at the same time, showing that sister locus cohesion in the origin region is local rather than extensive. We were unable to observe any influence on segregation of the proposed centromeric site, migS, or indeed any other potential cis-acting element on either replication arm (replichore) in the AB1157 genetic background. Site-specific inhibition of replication close to oriC on one replichore did not prevent segregation of loci on the other replichore. Inhibition of RNA synthesis and inhibition of the dynamic polymerization of the actin homolog MreB did not affect ori and bulk chromosome segregation.The chromosome of the extensively studied bacterium Escherichia coli undergoes simultaneous replication and segregation and has no apparent mitotic apparatus for chromosome segregation, a situation very different from that of eukaryotes, where replication and segregation occur in temporally separate periods of the cell cycle. An unsolved mystery of the bacterial cell cycle is how chromosome segregation takes place. Several mechanisms have been proposed to drive the segregation of origin and bulk DNA after replication. In one model, cell elongation is proposed to be a crucial factor, in which the two newly replicated origins are attached to the inner membrane and separated by cell growth between them along the long axis of the cell (25). However, it is now clear that elongation occurs throughout the cell and the movement of the origins is much faster than the rate of cell elongation, indicating that cell elongation alone is not responsible for segregation (55,60).Active partitioning systems were first found in low-copynumber plasmids, where they are required for stable inheritance by distributing the daughter plasmids to both daughter cells (reviewed in reference 14). These systems fall into two families; one uses the ParM actin and its associated protein and binding sites to drive newly replicated sister plasmids apart during cycles of actin polymerization and depolymerization (4, 19). The second parABS family is less well understood mechanistically, although ATP hydrolysis-dependent cycles of ParA movement appear to play a key role in the segregation process (48).Later, it was found that many bacterial chromosomes also utilize parABS systems for their segregation, for example, Bacillus subtilis (23, 37), Caulobacter crescentus (41), and both chromosomes of Vibrio cholerae (22). The typical chromosomal par locus consists of two genes, parA and parB (soj and spo0J in B. subtilis), and a cis-acting parS DNA element. ParB is a DNA-binding prote...

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Section: Vol 192 2010 E Coli Origin Segregation 6147mentioning

confidence: 90%

mentioning

confidence: 99%

Independent Segregation of the Two Arms of theEscherichia coli oriRegion Requires neither RNA Synthesis nor MreB Dynamics

Wang

Sherratt

2010

J Bacteriol

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“…This was confirmed by covisualizing CFP-RodZ and YFP-MreB ( Examining localization of RodZ in MreB-depleted cells or vice versa was not particularly informative (not shown) because of the poor health and the severe cell shape defect of these cells, conditions which affect FtsZ ring formation and likely cause other secondary effects. The drug A22 rapidly disrupts MreB localization (7), but the disruption is incomplete (20,25). Therefore, the maintenance of some GFP-RodZ medial localization in A22-treated cells (not shown) was inconclusive.…”

Section: Identification Of a Gene With An Essential Role In Cell Morpmentioning

confidence: 99%

RodZ, a component of the bacterial core morphogenic apparatus

Alyahya

Alexander

Costa

et al. 2009

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

162

219

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“…The long cell was generated by depletion of FtsZ in PYE glucose liquid medium for 150 min prior to induction of GFP-crescentin synthesis on the agarose-padded slide containing vanillic acid and lacking xylose. A22 is a drug that disrupts the MreB cytoskeleton , though this disruption is partial (Aaron et al 2007;Karczmarek et al 2007). Nevertheless, treatment of cells with A22 for 3 h resulted in cell widening and detachment of crescentin structures (Fig.…”

Section: Mreb Plays a Critical Role In Crescentin-mediated Cell Curvamentioning

confidence: 99%

Bacterial intermediate filaments: in vivo assembly, organization, and dynamics of crescentin

Charbon

Cabeen²,

Jacobs‐Wagner³

2009

Genes Dev.

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Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin also shares in vivo properties of assembly and dynamics with IF proteins by forming stable filamentous structures that continuously incorporate subunits along their length and that grow in a nonpolar fashion. De novo assembly of crescentin is biphasic and involves a cell size-dependent mechanism that controls the length of the structure by favoring lateral insertion of crescentin subunits over bipolar longitudinal extension when the structure ends reach the cell poles. The crescentin structure is stably anchored to the cell envelope, and this cellular organization requires MreB function, identifying a new function for MreB and providing a parallel to the role of actin in IF assembly and organization in metazoan cells. Additionally, analysis of an MreB localization mutant suggests that cell wall insertion during cell elongation normally occurs along two helices of opposite handedness, each counterbalancing the other's torque.[Keywords: Crescentin; Caulobacter crescentus; intermediate filament; MreB; in vivo assembly; dynamics] Supplemental material is available at http://www.genesdev.org.

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DNA and origin region segregation are not affected by the transition from rod to sphere after inhibition of Escherichia coli MreB by A22

Cited by 41 publications

References 2 publications

Independent Segregation of the Two Arms of theEscherichia coli oriRegion Requires neither RNA Synthesis nor MreB Dynamics

Independent Segregation of the Two Arms of theEscherichia coli oriRegion Requires neither RNA Synthesis nor MreB Dynamics

RodZ, a component of the bacterial core morphogenic apparatus

Bacterial intermediate filaments: in vivo assembly, organization, and dynamics of crescentin

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