Preferential cytoplasmic location of FtsZ, a protein essential for <i>Escherichia coli</i> septation

Pla, Jesús; Sánchez, M. Calderón De La Barca; Palacios, Pilar; Vicente, Miguel; Aldea, Martí

doi:10.1111/j.1365-2958.1991.tb01915.x

Cited by 81 publications

(73 citation statements)

References 20 publications

(16 reference statements)

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“…Using immunoblotting we found that on average the strain expresses 4100±1700 FtsZ molecules/cell under the same growth condition used for PALM imaging. This average expression level is consistent with previous reports (3000–5000 molecules/cell) [32], [33], but lower than the 10,000–15,000 molecules/cell reported by Lu et al [34]. The fusion protein FtsZ-mEos2 was expressed at approximately 25% of total cellular FtsZ (wt FtsZ + FtsZ-mEos2) at the induction level used for PALM imaging (Figure 1A).…”

Section: Resultssupporting

confidence: 91%

In Vivo Structure of the E. coli FtsZ-ring Revealed by Photoactivated Localization Microscopy (PALM)

et al. 2010

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The FtsZ protein, a tubulin-like GTPase, plays a pivotal role in prokaryotic cell division. In vivo it localizes to the midcell and assembles into a ring-like structure-the Z-ring. The Z-ring serves as an essential scaffold to recruit all other division proteins and generates contractile force for cytokinesis, but its supramolecular structure remains unknown. Electron microscopy (EM) has been unsuccessful in detecting the Z-ring due to the dense cytoplasm of bacterial cells, and conventional fluorescence light microscopy (FLM) has only provided images with limited spatial resolution (200–300 nm) due to the diffraction of light. Hence, given the small sizes of bacteria cells, identifying the in vivo structure of the Z-ring presents a substantial challenge. Here, we used photoactivated localization microscopy (PALM), a single molecule-based super-resolution imaging technique, to characterize the in vivo structure of the Z-ring in E. coli. We achieved a spatial resolution of ∼35 nm and discovered that in addition to the expected ring-like conformation, the Z-ring of E. coli adopts a novel compressed helical conformation with variable helical length and pitch. We measured the thickness of the Z-ring to be ∼110 nm and the packing density of FtsZ molecules inside the Z-ring to be greater than what is expected for a single-layered flat ribbon configuration. Our results strongly suggest that the Z-ring is composed of a loose bundle of FtsZ protofilaments that randomly overlap with each other in both longitudinal and radial directions of the cell. Our results provide significant insight into the spatial organization of the Z-ring and open the door for further investigations of structure-function relationships and cell cycle-dependent regulation of the Z-ring.

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Section: Resultssupporting

confidence: 91%

In Vivo Structure of the E. coli FtsZ-ring Revealed by Photoactivated Localization Microscopy (PALM)

et al. 2010

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“…It has been suggested that the function of the min locus is to prevent division from occurring at old sites (the cell poles) (24) and that this occurs through the action of an inhibitor, MinCD, and a topological specificity factor, MinE (9). The present results, as well as previous results (5) An underlying assumption of the hypothesis for min function is that the process leading to minicell formation is a normal septation event that is just abnormally located.…”

Section: Discussionsupporting

confidence: 78%

“…Previous results have shown that FtsZ, an essential cell division protein (8,24,26), is localized in a ring-like structure at the future division site immediately before division occurs (5). In this study, we have found that two inhibitors of cell division, SulA and the bipartite MinCD inhibitor, block the formation of the FtsZ ring at potential division sites.…”

Section: Discussionmentioning

confidence: 50%

Cell division inhibitors SulA and MinCD prevent formation of the FtsZ ring

1993

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Immunoelectron microscopy was used to assess the effects of inhibitors of cell division on formation of the FtsZ ring in Eschlerichia coli. Induction of the cell division inhibitor SulA, a component of the SOS response, or the inhibitor MinCD, a component of the min system, blocked formation of the FtsZ ring and led to filamentation. Reversal of SulA inhibition by blocking protein synthesis in SulA-induced filaments led to a resumption of FtsZ ring formation and division. These results suggested that these inhibitors block cell division by preventing FtsZ localization into the ring structure. In addition, analysis of min mutants demonstrated that FtsZ ring formation was also associated with minicell formation, indicating that all septation events in E. coli involve the FtsZ ring.In Escherichia coli, cell division occurs near the midpoint of the long axis of the cell shortly after completion of chromosome replication (11). This temporal and spatial regulation of the cell division event is responsible for the narrow cell length distribution observed with exponentially growing cultures. In addition, the coordination of the cell division event with DNA segregation is responsible for the virtual absence of DNA-less cells in cultures. Under some conditions, however, this coordination between these two events is altered, leading to either inhibition of division or misplacement of the division event. Such disturbances of the coordination between the division event and DNA segregation lead to filamentation and/or production of anucleate cells, including minicells.Inhibition of cell division following interruption of DNA replication is due in part to the induction of sulA, a member of the SOS regulon (13, 14). SulA is thought to inhibit division by direct interaction with FtsZ, inhibiting its essential division activity (3,16,18). The inhibition is readily reversible, and division activity is restored as soon as SulA is removed, even without additional FtsZ synthesis (20).Proper placement of the division event is in part due to the min system, which is thought to prevent old sites (the cell poles) from being reused (25). In the absence of the min system, the poles become accessible to the division machinery, resulting in minicell production. The min system utilizes a bipartite division inhibitor, MinCD, and an additional gene product, MinE, that appears to confer topological specificity to the inhibitor (9). MATERIALS AND METHODS Bacterial strains, plasmids, and phage. The E. coli K-12 bacterial strains used in this study were derivatives of MC4100 (5) and BS100 (19). For examination of the effect of sulA, an MC4100 derivative containing plasmids pJF118EH (12) and pUGM470 (obtained from S. Gottesman) was used. The pJF118EH provides the lac repressor, and the pUGM470 has the sulA gene downstream of the lac promoter. BEF51 is an MC4100 derivative carrying a min deletion P1 transduced from PB114 (9). To examine the effects of minCD induction, BS100 containing XDB173, a transducing phage containing the minCD genes downstream ...

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“…More recently this designation was confirmed when it was shown that the ftsZ gene was essential and that reducing expression of the gene led to inhibition of division (6,18,24). Surprisingly, however, the ftsZ84(Ts) mutation remains the only conditional lethal mutation in theftsZ gene, as no additional alleles were found among cell division mutants selected on the basis of a filamenting phenotype (9).…”

mentioning

confidence: 76%

Isolation and characterization of ftsZ alleles that affect septal morphology

Lutkenhaus

1992

J Bacteriol

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TheftsZ gene encodes an essential cell division protein that specifically localizes to the septum of dividing cells. In this study we characterized the effects of theftsZ2(Rsa) mutation on cell physiology. We found that this mutation caused an altered cell morphology that included minicell formation and an increased average cell length. In addition, this mutation caused a temperature-dependent effect on cell lysis. During this investigation we fortuitously isolated a novel temperature-sensitiveftsZ mutation that consisted of a 6-codon insertion near the 5' end of the gene. This mutation, designated ftsZ26(Ts), caused an altered polar morphology at the permissive temperature and blocked cell division at the nonpermissive temperature. The altered polar morphology resulted from cell division and correlated with an altered geometry of the FtsZ ring. An intragenic cold-sensitive suppressor of ftsZ26(Ts) that caused cell lysis at the nonpermissive temperature was isolated.These results support the hypothesis that the FtsZ ring determines the division site and interacts with the septal biosynthetic machinery.The ftsZ gene was classified as a cell division gene on the basis of the filamentous phenotype conferred by the conditional lethal ftsZ84(Ts) mutation at the nonpermissive temperature (16). More recently this designation was confirmed when it was shown that the ftsZ gene was essential and that reducing expression of the gene led to inhibition of division (6,18,24). Surprisingly, however, the ftsZ84(Ts) mutation remains the only conditional lethal mutation in theftsZ gene, as no additional alleles were found among cell division mutants selected on the basis of a filamenting phenotype (9). In contrast, numerous conditional lethal mutations have been found in the ftsA and ftsI genes.In the absence of ftsZ function, observed in strains that conditionally express ftsZ or express the ftsZ84(Ts) mutation, cells form smooth filaments with no sign of constriction (6). Such morphology suggests that FtsZ acts earlier in cell division than other knownfts genes, since mutations in these genes result in filaments with indentations at regular intervals that may be aborted or stalled division attempts (9). In contrast to the effect of reducing ftsZ expression, slight overexpression offtsZ results in hyperdivision activity in the form of a minicell phenotype, although further overexpression also inhibits division (1,25 have been designated ftsZ(Rsa) (2). These mutations appear to alter the ftsZ gene product such that it is resistant to SulA (14, 15). These same mutations also confer increased resistance to the cell division inhibitor MinCD, which is part of the min system (3). Although these mutations are not conditional lethals, at least some of these ftsZ(Rsa) mutations confer a slightly temperature-sensitive cell division phenotype, especially at low salt concentrations (10,12,13). Most of these ftsZ(Rsa) mutations were isolated at the chromosomal locus; however, ftsZl(Rsa), ftsZ2(Rsa), and ftsZ3(Rsa) were obtained on a low-copy...

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Preferential cytoplasmic location of FtsZ, a protein essential for Escherichia coli septation

Cited by 81 publications

References 20 publications

In Vivo Structure of the E. coli FtsZ-ring Revealed by Photoactivated Localization Microscopy (PALM)

In Vivo Structure of the E. coli FtsZ-ring Revealed by Photoactivated Localization Microscopy (PALM)

Cell division inhibitors SulA and MinCD prevent formation of the FtsZ ring

Isolation and characterization of ftsZ alleles that affect septal morphology

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