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Joe Lutkenhaus - One of the best experts on this subject based on the ideXlab platform.
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Minc Mind copolymers are not required for Min Function
Molecular Microbiology, 2015Co-Authors: Kyungtae Park, Shishen Du, Joe LutkenhausAbstract:: In Escherichia coli, precise placement of the cytokinetic Z ring at midcell requires the concerted action of the three Min proteins. MinD activates MinC, an inhibitor of FtsZ, at least in part, by recruiting it to the membrane and targeting it to the Z ring, while MinE stimulates the MinD ATPase inducing an oscillation that directs MinC/MinD activity away from midcell. Recently, MinC and MinD were shown to form copolymers of alternating dimers of MinC and MinD, and it was suggested that these copolymers are the active form of MinC/MinD. Here, we use MinD mutants defective in binding MinC to generate heterodimers with wild-type MinD that are unable to form MinC/MinD copolymers. Similarly, MinC mutants defective in binding to MinD were used to generate heterodimers with wild-type MinC that are unable to form copolymers. Such heterodimers are active and in the case of MinC were shown to mediate spatial regulation of the Z ring demonstrating that MinC/MinD copolymer formation is not required. Our results are consistent with a model in which a membrane anchored MinC/MinD complex is targeted to the Z ring through the conserved carboxy tail of FtsZ leading to breakage of FtsZ filaments.
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analysis of Minc reveals two independent domains involved in interaction with Mind and ftsz
Journal of Bacteriology, 2000Co-Authors: Zonglin Hu, Joe LutkenhausAbstract:In Escherichia coli FtsZ assembles into a Z ring at midcell while assembly at polar sites is prevented by the Min system. MinC, a component of this system, is an inhibitor of FtsZ assembly that is positioned within the cell by interaction with MinDE. In this study we found that MinC consists of two Functional domains connected by a short linker. When fused to MalE the N-terMinal domain is able to inhibit cell division and prevent FtsZ assembly in vitro. The C-terMinal domain interacts with MinD, and expression in wild-type cells as a MalE fusion disrupts Min Function, resulting in a Minicell phenotype. We also find that MinC is an oligomer, probably a dimer. Although the C-terMinal domain is clearly sufficient for oligomerization, the N-terMinal domain also promotes oligomerization. These results demonstrate that MinC consists of two independently Functioning domains: an N-terMinal domain capable of inhibiting FtsZ assembly and a C-terMinal domain responsible for localization of MinC through interaction with MinD. The fusion of these two independent domains is required to achieve topological regulation of Z ring assembly.
Jeff Errington - One of the best experts on this subject based on the ideXlab platform.
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a novel component of the division site selection system of bacillus subtilis and a new mode of action for the division inhibitor Mincd
Molecular Microbiology, 2008Co-Authors: Marc Bramkamp, Robyn Emmins, Louise Weston, Catriona Donovan, Richard A Daniel, Jeff ErringtonAbstract:Cell division in bacteria is governed by a complex cytokinetic machinery in which the key player is a tubulin homologue, FtsZ. Most rod-shaped bacteria divide precisely at mid-cell between segregated sister chromosomes. Selection of the correct site for cell division is thought to be deterMined by two negative regulatory systems: the nucleoid occlusion system, which prevents division in the vicinity of the chromosomes, and the Min system, which prevents inappropriate division at the cell poles. In Bacillus subtilis recruitment of the division inhibitor MinCD to cell poles depends on DivIVA, and these proteins were thought to be sufficient for Min Function. We have now identified a novel component of the division-site selection system, MinJ, which bridges DivIVA and MinD. MinJ mutants are impaired in division because MinCD activity is no longer restricted to cell poles. Although MinCD was thought to act specifically on FtsZ assembly, analysis of MinJ and divIVA mutants showed that their block in division occurs downstream of FtsZ. The results support a model in which the main Function of the Min system lies in allowing only a single round of division per cell cycle, and that MinCD acts at multiple levels to prevent inappropriate division.
Marc Bramkamp - One of the best experts on this subject based on the ideXlab platform.
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a novel component of the division site selection system of bacillus subtilis and a new mode of action for the division inhibitor Mincd
Molecular Microbiology, 2008Co-Authors: Marc Bramkamp, Robyn Emmins, Louise Weston, Catriona Donovan, Richard A Daniel, Jeff ErringtonAbstract:Cell division in bacteria is governed by a complex cytokinetic machinery in which the key player is a tubulin homologue, FtsZ. Most rod-shaped bacteria divide precisely at mid-cell between segregated sister chromosomes. Selection of the correct site for cell division is thought to be deterMined by two negative regulatory systems: the nucleoid occlusion system, which prevents division in the vicinity of the chromosomes, and the Min system, which prevents inappropriate division at the cell poles. In Bacillus subtilis recruitment of the division inhibitor MinCD to cell poles depends on DivIVA, and these proteins were thought to be sufficient for Min Function. We have now identified a novel component of the division-site selection system, MinJ, which bridges DivIVA and MinD. MinJ mutants are impaired in division because MinCD activity is no longer restricted to cell poles. Although MinCD was thought to act specifically on FtsZ assembly, analysis of MinJ and divIVA mutants showed that their block in division occurs downstream of FtsZ. The results support a model in which the main Function of the Min system lies in allowing only a single round of division per cell cycle, and that MinCD acts at multiple levels to prevent inappropriate division.
Kyungtae Park - One of the best experts on this subject based on the ideXlab platform.
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Minc Mind copolymers are not required for Min Function
Molecular Microbiology, 2015Co-Authors: Kyungtae Park, Shishen Du, Joe LutkenhausAbstract:: In Escherichia coli, precise placement of the cytokinetic Z ring at midcell requires the concerted action of the three Min proteins. MinD activates MinC, an inhibitor of FtsZ, at least in part, by recruiting it to the membrane and targeting it to the Z ring, while MinE stimulates the MinD ATPase inducing an oscillation that directs MinC/MinD activity away from midcell. Recently, MinC and MinD were shown to form copolymers of alternating dimers of MinC and MinD, and it was suggested that these copolymers are the active form of MinC/MinD. Here, we use MinD mutants defective in binding MinC to generate heterodimers with wild-type MinD that are unable to form MinC/MinD copolymers. Similarly, MinC mutants defective in binding to MinD were used to generate heterodimers with wild-type MinC that are unable to form copolymers. Such heterodimers are active and in the case of MinC were shown to mediate spatial regulation of the Z ring demonstrating that MinC/MinD copolymer formation is not required. Our results are consistent with a model in which a membrane anchored MinC/MinD complex is targeted to the Z ring through the conserved carboxy tail of FtsZ leading to breakage of FtsZ filaments.
Richard A Daniel - One of the best experts on this subject based on the ideXlab platform.
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a novel component of the division site selection system of bacillus subtilis and a new mode of action for the division inhibitor Mincd
Molecular Microbiology, 2008Co-Authors: Marc Bramkamp, Robyn Emmins, Louise Weston, Catriona Donovan, Richard A Daniel, Jeff ErringtonAbstract:Cell division in bacteria is governed by a complex cytokinetic machinery in which the key player is a tubulin homologue, FtsZ. Most rod-shaped bacteria divide precisely at mid-cell between segregated sister chromosomes. Selection of the correct site for cell division is thought to be deterMined by two negative regulatory systems: the nucleoid occlusion system, which prevents division in the vicinity of the chromosomes, and the Min system, which prevents inappropriate division at the cell poles. In Bacillus subtilis recruitment of the division inhibitor MinCD to cell poles depends on DivIVA, and these proteins were thought to be sufficient for Min Function. We have now identified a novel component of the division-site selection system, MinJ, which bridges DivIVA and MinD. MinJ mutants are impaired in division because MinCD activity is no longer restricted to cell poles. Although MinCD was thought to act specifically on FtsZ assembly, analysis of MinJ and divIVA mutants showed that their block in division occurs downstream of FtsZ. The results support a model in which the main Function of the Min system lies in allowing only a single round of division per cell cycle, and that MinCD acts at multiple levels to prevent inappropriate division.