scholarly journals ARC3 Activation by PARC6 Promotes FtsZ-Ring Remodeling at the Chloroplast Division Site

2019 ◽  
Vol 31 (4) ◽  
pp. 862-885
Author(s):  
Cheng Chen ◽  
Lingyan Cao ◽  
Yue Yang ◽  
Katie J. Porter ◽  
Katherine W. Osteryoung
Keyword(s):  
Chloroplast Division ◽  
Ftsz Ring ◽  
Division Site

scholarly journals The Assembly of the FtsZ Ring at the Mid-Chloroplast Division Site Depends on a Balance Between the Activities of AtMinE1 and ARC11/AtMinD1

2008 ◽  
Vol 49 (3) ◽  
pp. 345-361 ◽  
Author(s):  
Makoto T. Fujiwara ◽  
Haruki Hashimoto ◽  
Yusuke Kazama ◽  
Tomoko Abe ◽  
Shigeo Yoshida ◽  
...  
Keyword(s):  
Chloroplast Division ◽  
Ftsz Ring ◽  
Division Site

scholarly journals Effects of Perturbing Nucleoid Structure on Nucleoid Occlusion-Mediated Toporegulation of FtsZ Ring Assembly

2004 ◽  
Vol 186 (12) ◽  
pp. 3951-3959 ◽  
Author(s):  
Qin Sun ◽  
William Margolin
Keyword(s):  
Chromosome Segregation ◽  
Potential Role ◽  
Membrane Insertion ◽  
Translation Inhibition ◽  
Ftsz Ring ◽  
Division Site ◽  
Ring Assembly ◽  
Z Ring ◽  
Nucleoid Structure

ABSTRACT In Escherichia coli, assembly of the FtsZ ring (Z ring) at the cell division site is negatively regulated by the nucleoid in a phenomenon called nucleoid occlusion (NO). Previous studies have indicated that chromosome packing plays a role in NO, as mukB mutants grown in rich medium often exhibit FtsZ rings on top of diffuse, unsegregated nucleoids. To address the potential role of overall nucleoid structure on NO, we investigated the effects of disrupting chromosome structure on Z-ring positioning. We found that NO was mostly normal in cells with inactivated DNA gyrase or in mukB-null mutants lacking topA, although some suppression of NO was evident in the latter case. Previous reports suggesting that transcription, translation, and membrane insertion of proteins (“transertion”) influence nucleoid structure prompted us to investigate whether disruption of these activities had effects on NO. Blocking transcription caused nucleoids to become diffuse, and FtsZ relocalized to multiple bands on top of these nucleoids, biased towards midcell. This suggested that these diffuse nucleoids were defective in NO. Blocking translation with chloramphenicol caused characteristic nucleoid compaction, but FtsZ rarely assembled on top of these centrally positioned nucleoids. This suggested that NO remained active upon translation inhibition. Blocking protein secretion by thermoinduction of a secA(Ts) strain caused a chromosome segregation defect similar to that in parC mutants, and NO was active. Although indirect effects are certainly possible with these experiments, the above data suggest that optimum NO activity may require specific organization and structure of the nucleoid.

scholarly journals Chloroplast division checkpoint in eukaryotic algae

2016 ◽  
Vol 113 (47) ◽  
pp. E7629-E7638 ◽  
Author(s):  
Nobuko Sumiya ◽  
Takayuki Fujiwara ◽  
Atsuko Era ◽  
Shin-ya Miyagishima
Keyword(s):  
Cell Cycle ◽  
Host Cell ◽  
Cell Cycle Progression ◽  
Chloroplast Division ◽  
Dominant Negative ◽  
Cyanidioschyzon Merolae ◽  
Temperature Sensitive ◽  
Specific Expression ◽  
Cycle Progression ◽  
Division Site

Chloroplasts evolved from a cyanobacterial endosymbiont. It is believed that the synchronization of endosymbiotic and host cell division, as is commonly seen in existing algae, was a critical step in establishing the permanent organelle. Algal cells typically contain one or only a small number of chloroplasts that divide once per host cell cycle. This division is based partly on the S-phase–specific expression of nucleus-encoded proteins that constitute the chloroplast-division machinery. In this study, using the red alga Cyanidioschyzon merolae, we show that cell-cycle progression is arrested at the prophase when chloroplast division is blocked before the formation of the chloroplast-division machinery by the overexpression of Filamenting temperature-sensitive (Fts) Z2-1 (Fts72-1), but the cell cycle progresses when chloroplast division is blocked during division-site constriction by the overexpression of either FtsZ2-1 or a dominant-negative form of dynamin-related protein 5B (DRP5B). In the cells arrested in the prophase, the increase in the cyclin B level and the migration of cyclin-dependent kinase B (CDKB) were blocked. These results suggest that chloroplast division restricts host cell-cycle progression so that the cell cycle progresses to the metaphase only when chloroplast division has commenced. Thus, chloroplast division and host cell-cycle progression are synchronized by an interactive restriction that takes place between the nucleus and the chloroplast. In addition, we observed a similar pattern of cell-cycle arrest upon the blockage of chloroplast division in the glaucophyte alga Cyanophora paradoxa, raising the possibility that the chloroplast division checkpoint contributed to the establishment of the permanent organelle.

scholarly journals Cell-free biogenesis of bacterial division proto-rings that can constrict liposomes

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Elisa Godino ◽  
Jonás Noguera López ◽  
Ilias Zarguit ◽  
Anne Doerr ◽  
Mercedes Jimenez ◽  
...  
Keyword(s):  
Cytoskeletal Proteins ◽  
Ftsz Ring ◽  
Division Site ◽  
Artificial Cell ◽  
Bacterial Division ◽  
Synthetic Cell ◽  
Free Gene ◽  
Bacterial Cell Cycle ◽  
Planar Membranes ◽  
Genetic Programme

AbstractA major challenge towards the realization of an autonomous synthetic cell resides in the encoding of a division machinery in a genetic programme. In the bacterial cell cycle, the assembly of cytoskeletal proteins into a ring defines the division site. At the onset of the formation of the Escherichia coli divisome, a proto-ring consisting of FtsZ and its membrane-recruiting proteins takes place. Here, we show that FtsA-FtsZ ring-like structures driven by cell-free gene expression can be reconstituted on planar membranes and inside liposome compartments. Such cytoskeletal structures are found to constrict the liposome, generating elongated membrane necks and budding vesicles. Additional expression of the FtsZ cross-linker protein ZapA yields more rigid FtsZ bundles that attach to the membrane but fail to produce budding spots or necks in liposomes. These results demonstrate that gene-directed protein synthesis and assembly of membrane-constricting FtsZ-rings can be combined in a liposome-based artificial cell.

scholarly journals Cell Cycle-regulated, Microtubule-independent Organelle Division in Cyanidioschyzon merolae

2005 ◽  
Vol 16 (5) ◽  
pp. 2493-2502 ◽  
Author(s):  
Keiji Nishida ◽  
Fumi Yagisawa ◽  
Haruko Kuroiwa ◽  
Toshiyuki Nagata ◽  
Tsuneyoshi Kuroiwa
Keyword(s):  
Cell Cycle ◽  
Spindle Pole ◽  
Chloroplast Division ◽  
Mitochondrial Morphology ◽  
Cyanidioschyzon Merolae ◽  
Microtubule Organization ◽  
Mitochondrial Division ◽  
Protein Levels ◽  
Division Site ◽  
Organelle Division

Mitochondrial and chloroplast division controls the number and morphology of organelles, but how cells regulate organelle division remains to be clarified. Here, we show that each step of mitochondrial and chloroplast division is closely associated with the cell cycle in Cyanidioschyzon merolae. Electron microscopy revealed direct associations between the spindle pole bodies and mitochondria, suggesting that mitochondrial distribution is physically coupled with mitosis. Interconnected organelles were fractionated under microtubule-stabilizing condition. Immunoblotting analysis revealed that the protein levels required for organelle division increased before microtubule changes upon cell division, indicating that regulation of protein expression for organelle division is distinct from that of cytokinesis. At the mitochondrial division site, dynamin stuck to one of the divided mitochondria and was spatially associated with the tip of a microtubule stretching from the other one. Inhibition of microtubule organization, proteasome activity or DNA synthesis, respectively, induced arrested cells with divided but shrunk mitochondria, with divided and segregated mitochondria, or with incomplete mitochondrial division restrained at the final severance, and repetitive chloroplast division. The results indicated that mitochondrial morphology and segregation but not division depend on microtubules and implied that the division processes of the two organelles are regulated at distinct checkpoints.

scholarly journals MapZ forms a stable ring structure that acts as a nano-track for FtsZ treadmilling inStreptococcus mutans

2017 ◽  
Author(s):  
Yongliang Li ◽  
Shipeng Shao ◽  
Xiao Xu ◽  
Xiaodong Su ◽  
Yujie Sun ◽  
...  
Keyword(s):  
Single Molecule ◽  
Super Resolution ◽  
Ring Structure ◽  
Antibacterial Drug ◽  
Ftsz Ring ◽  
Division Site ◽  
Binary Division ◽  
Z Ring ◽  
Vital Component ◽  
Stable Ring

AbstractBacterial binary division requires the accurate placement of the division machinery. FtsZ, the vital component of the division machinery, can assemble into filaments and self-organize into a ring structure (Z-ring) at the proper site for cell division. Thus, understanding how bacteria control the spatiotemporal formation of the FtsZ ring is crucial for small molecule and nanoparticle antibacterial drug discovery. MapZ, a recently identified FtsZ regulator inStreptococcaceae,has been found to localize at the mid-cell and position the FtsZ ring. However, the mechanism is still unclear. Here, by using total internal reflection fluorescence microscopy, super-resolution imaging, and single molecule tracking, we investigated the mechanism by which MapZ regulates the FtsZ ring position. The results show that FtsZ exhibites dynamic treadmilling motion in S.mutans.Importantly, depletion of MapZ leads to an unconstrained movement of treadmilling FtsZ filaments and a shorter lifetime of the constricting FtsZ ring. Furthermore, by revealing that MapZ forms an immobile ring-like nanostructure at the division site, our study suggests that MapZ forms a stable ring that acts as a nanotrack to guide and restrict treadmilling FtsZ filaments in S.mutans, representing a novel way in which bacteria control the division.

scholarly journals PomX, a ParA/MinD ATPase activating protein, is a triple regulator of cell division in Myxococcus xanthus

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Dominik Schumacher ◽  
Andrea Harms ◽  
Silke Bergeler ◽  
Erwin Frey ◽  
Lotte Sogaard-Andersen
Keyword(s):  
Cell Division ◽  
Myxococcus Xanthus ◽  
Dependent Manner ◽  
Ftsz Ring ◽  
Work Support ◽  
Terminal Domain ◽  
Division Site ◽  
The Social ◽  
Underlying Mechanisms ◽  
Positively Charged

Cell division site positioning is precisely regulated but the underlying mechanisms are incompletely understood. In the social bacterium Myxococcus xanthus, the ~15 MDa tripartite PomX/Y/Z complex associates with and translocates across the nucleoid in a PomZ ATPase-dependent manner to directly position and stimulate formation of the cytokinetic FtsZ-ring at midcell, and then undergoes fission during division. Here, we demonstrate that PomX consists of two functionally distinct domains and has three functions. The N-terminal domain stimulates ATPase activity of the ParA/MinD ATPase PomZ. The C-terminal domain interacts with PomY and forms polymers, which serve as a scaffold for PomX/Y/Z complex formation. Moreover, the PomX/PomZ interaction is important for fission of the PomX/Y/Z complex. These observations together with previous work support that the architecturally diverse ATPase activating proteins of ParA/MinD ATPases are highly modular and use the same mechanism to activate their cognate ATPase via a short positively charged N-terminal extension.

scholarly journals Growth Rate-Dependent Regulation of Medial FtsZ Ring Formation

2003 ◽  
Vol 185 (9) ◽  
pp. 2826-2834 ◽  
Author(s):  
Richard B. Weart ◽  
Petra Anne Levin
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Transcriptional Control ◽  
Doubling Time ◽  
Ring Formation ◽  
Intracellular Concentration ◽  
Dependent Manner ◽  
Ftsz Ring ◽  
Division Site ◽  
Rate Dependent

ABSTRACT FtsZ is an essential cell division protein conserved throughout the bacteria and archaea. In response to an unknown cell cycle signal, FtsZ polymerizes into a ring that establishes the future division site. We conducted a series of experiments examining the link between growth rate, medial FtsZ ring formation, and the intracellular concentration of FtsZ in the gram-positive bacterium Bacillus subtilis. We found that, although the frequency of cells with FtsZ rings varies as much as threefold in a growth rate-dependent manner, the average intracellular concentration of FtsZ remains constant irrespective of doubling time. Additionally, expressing ftsZ solely from a constitutive promoter, thereby eliminating normal transcriptional control, did not alter the growth rate regulation of medial FtsZ ring formation. Finally, our data indicate that overexpressing FtsZ does not dramatically increase the frequency of cells with medial FtsZ rings, suggesting that the mechanisms governing ring formation are refractile to increases in FtsZ concentration. These results support a model in which the timing of FtsZ assembly is governed primarily through cell cycle-dependent changes in FtsZ polymerization kinetics and not simply via oscillations in the intracellular concentration of FtsZ. Importantly, this model can be extended to the gram-negative bacterium Escherichia coli. Our data show that, like those in B. subtilis, average FtsZ levels in E. coli are constant irrespective of doubling time.

scholarly journals CDP1, a novel component of chloroplast division site positioning system in Arabidopsis

Cell Research ◽  
2009 ◽  
Vol 19 (7) ◽  
pp. 877-886 ◽  
Author(s):  
Min Zhang ◽  
Yong Hu ◽  
Jingjing Jia ◽  
Dapeng Li ◽  
Runjie Zhang ◽  
...  
Keyword(s):  
Chloroplast Division ◽  
Positioning System ◽  
Division Site
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