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

2020 ◽  
Author(s):  
Dominik Schumacher ◽  
Andrea Harms ◽  
Silke Bergeler ◽  
Erwin Frey ◽  
Lotte Søgaard-Andersen
Keyword(s):  
Cell Division ◽  
Myxococcus Xanthus ◽  
Dependent Manner ◽  
Ftsz Ring ◽  
Daughter Cells ◽  
Terminal Domain ◽  
Division Site ◽  
The Social ◽  
Interaction Interaction ◽  
Positively Charged

SummaryCell division is precisely regulated to generate daughter cells of correct size and shape. In the social bacterium Myxococcus xanthus, the tripartite PomX/Y/Z complex directly stimulates positioning of the cytokinetic FtsZ-ring at midcell to mark the division site. The ∼15 MDa PomX/Y/Z complex associates with the nucleoid in a PomZ-dependent manner, translocates to midcell to stimulate FtsZ-ring formation, and undergoes fission during division. We demonstrate that PomX consists of two functionally distinct domains and has three functions. The N-terminal domain interacts with the ParA/MinD ATPase PomZ and stimulates PomZ ATPase activity. The C-terminal domain mediates PomX self-interaction, interaction to PomY, and serves as a scaffold for PomX/Y/Z complex formation. Moreover, the PomX/PomZ interaction is important for fission. 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 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 Changes in the Min Oscillation Pattern before and after Cell Birth

2010 ◽  
Vol 192 (16) ◽  
pp. 4134-4142 ◽  
Author(s):  
Jennifer R. Juarez ◽  
William Margolin
Keyword(s):  
Cell Division ◽  
Fluorescent Protein ◽  
Time Lapse ◽  
The Other ◽  
Cell Pole ◽  
Daughter Cells ◽  
Division Site ◽  
Before And After ◽  
Dividing Cells ◽  
Green Fluorescent

ABSTRACT The Min system regulates the positioning of the cell division site in many bacteria. In Escherichia coli, MinD migrates rapidly from one cell pole to the other. In conjunction with MinC, MinD helps to prevent unwanted FtsZ rings from assembling at the poles and to stabilize their positioning at midcell. Using time-lapse microscopy of growing and dividing cells expressing a gfp-minD fusion, we show that green fluorescent protein (GFP)-MinD often paused at midcell in addition to at the poles, and the frequency of midcell pausing increased as cells grew longer and cell division approached. At later stages of septum formation, GFP-MinD often paused specifically on only one side of the septum, followed by migration to the other side of the septum or to a cell pole. About the time of septum closure, this irregular pattern often switched to a transient double pole-to-pole oscillation in the daughter cells, which ultimately became a stable double oscillation. The splitting of a single MinD zone into two depends on the developing septum and is a potential mechanism to explain how MinD is distributed equitably to both daughter cells. Septal pausing of GFP-MinD did not require MinC, suggesting that MinC-FtsZ interactions do not drive MinD-septal interactions, and instead MinD recognizes a specific geometric, lipid, and/or protein target at the developing septum. Finally, we observed regular end-to-end oscillation over very short distances along the long axes of minicells, supporting the importance of geometry in MinD localization.

scholarly journals Characterization of YmgF, a 72-Residue Inner Membrane Protein That Associates with the Escherichia coli Cell Division Machinery

2008 ◽  
Vol 191 (1) ◽  
pp. 333-346 ◽  
Author(s):  
Gouzel Karimova ◽  
Carine Robichon ◽  
Daniel Ladant
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Membrane Protein ◽  
Integral Membrane Protein ◽  
Dependent Manner ◽  
E Coli ◽  
Division Site ◽  
Inner Membrane Protein ◽  
Two Hybrid

ABSTRACT Formation of the Escherichia coli division septum is catalyzed by a number of essential proteins (named Fts) that assemble into a ring-like structure at the future division site. Many of these Fts proteins are intrinsic transmembrane proteins whose functions are largely unknown. In the present study, we attempted to identify a novel putative component(s) of the E. coli cell division machinery by searching for proteins that could interact with known Fts proteins. To do that, we used a bacterial two-hybrid system based on interaction-mediated reconstitution of a cyclic AMP (cAMP) signaling cascade to perform a library screening in order to find putative partners of E. coli cell division protein FtsL. Here we report the characterization of YmgF, a 72-residue integral membrane protein of unknown function that was found to associate with many E. coli cell division proteins and to localize to the E. coli division septum in an FtsZ-, FtsA-, FtsQ-, and FtsN-dependent manner. Although YmgF was previously shown to be not essential for cell viability, we found that when overexpressed, YmgF was able to overcome the thermosensitive phenotype of the ftsQ1(Ts) mutation and restore its viability under low-osmolarity conditions. Our results suggest that YmgF might be a novel component of the E. coli cell division machinery.

scholarly journals TTK/hMps1 Mediates the p53-Dependent Postmitotic Checkpoint by Phosphorylating p53 at Thr18

2009 ◽  
Vol 29 (11) ◽  
pp. 2935-2944 ◽  
Author(s):  
Yi-Fu Huang ◽  
Margaret Dah-Tsyr Chang ◽  
Sheau-Yann Shieh
Keyword(s):  
Cell Division ◽  
Genome Stability ◽  
Spindle Checkpoint ◽  
Underlying Mechanism ◽  
Dependent Manner ◽  
Deficient Mutant ◽  
Present Evidence ◽  
Checkpoint Kinase ◽  
Terminal Domain

ABSTRACT Upon prolonged arrest in mitosis, cells undergo adaptation and exit mitosis without cell division. These tetraploid cells are either eliminated by apoptosis or arrested in the subsequent G1 phase in a spindle checkpoint- and p53-dependent manner. p53 has long been known to be activated by spindle poisons, such as nocodazole and Taxol, although the underlying mechanism remains elusive. Here we present evidence that stabilization and activation of p53 by spindle disruption requires the spindle checkpoint kinase TTK/hMps1. TTK/hMps1 phoshorylates the N-terminal domain of p53 at Thr18, and this phosphorylation disrupts the interaction with MDM2 and abrogates MDM2-mediated p53 ubiquitination. Phosphorylation at Thr18 enhances p53-dependent activation of not only p21 but also Lats2, two mediators of the postmitotic checkpoint. Furthermore, a phospho-mimicking substitution at Thr18 (T18D) is more competent than the phospho-deficient mutant (T18A) in rescuing the tetraploid checkpoint defect of p53-depleted cells. Our findings therefore provide a mechanism connecting the spindle checkpoint with p53 in the maintenance of genome stability.

scholarly journals Positioning the Flagellum at the Center of a Dividing Cell To Combine Bacterial Division with Magnetic Polarity

mBio ◽  
2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Christopher T. Lefèvre ◽  
Mathieu Bennet ◽  
Stefan Klumpp ◽  
Damien Faivre
Keyword(s):  
Cell Division ◽  
Magnetic Dipole ◽  
Molecular Mechanisms ◽  
Magnetotactic Bacteria ◽  
Structural Features ◽  
Magnetic Polarity ◽  
Cellular Division ◽  
Daughter Cells ◽  
Division Site ◽  
The Moment

ABSTRACTFaithful replication of all structural features is asine qua noncondition for the success of bacterial reproduction by binary fission. For some species, a key challenge is to replicate and organize structures with multiple polarities. Polarly flagellated magnetotactic bacteria are the prime example of organisms dealing with such a dichotomy; they have the challenge of bequeathing two types of polarities to their daughter cells: magnetic and flagellar polarities. Indeed, these microorganisms align and move in the Earth's magnetic field using an intracellular chain of nano-magnets that imparts a magnetic dipole to the cell. The paradox is that, after division occurs in cells, if the new flagellum is positioned opposite to the old pole devoid of a flagellum during cell division, the two daughter cells will have opposite magnetic polarities with respect to the positions of their flagella. Here we show that magnetotactic bacteria of the classGammaproteobacteriapragmatically solve this problem by synthesizing a new flagellum at the division site. In addition, we model this particular structural inheritance during cell division. This finding opens up new questions regarding the molecular aspects of the new division mechanism, the way other polarly flagellated magnetotactic bacteria control the rotational direction of their flagella, and the positioning of organelles.IMPORTANCEMagnetotactic bacteria produce chains of magnetic nanoparticles that endow the cells with a magnetic dipole, a “compass” used for navigation. This feature, however, also drastically complicates cellular division in the case of polarly flagellated bacteria. In this case, the bacteria have to pass on to their daughter cells two types of cellular polarities simultaneously, their magnetic polarity and the polarity of their motility apparatus. We show here that magnetotactic bacteria of theGammaproteobacteriaclass pragmatically solve this problem by synthesizing the new flagellum at the division site, a division scheme never observed so far in bacteria. Even though the molecular mechanisms behind this scheme cannot be resolved at the moment due to the lack of genetic tools, this discovery provides a new window into the organizational complexity of simple organisms.

scholarly journals LocZ Is a New Cell Division Protein Involved in Proper Septum Placement in Streptococcus pneumoniae

mBio ◽  
2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Nela Holečková ◽  
Linda Doubravová ◽  
Orietta Massidda ◽  
Virginie Molle ◽  
Karolína Buriánková ◽  
...  
Keyword(s):  
Cell Division ◽  
Streptococcus Pneumoniae ◽  
Protein Kinase ◽  
Bacterial Cell Division ◽  
Content Type ◽  
Daughter Cells ◽  
Division Site ◽  
Z Ring ◽  
Specific Shape ◽  
Cell Division Protein

ABSTRACTHow bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement inStreptococcus pneumoniae. We show thatlocZis not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division.IMPORTANCEBacterial cell division is a highly ordered process regulated in time and space. Recently, we reported that the Ser/Thr protein kinase StkP regulates cell division in Streptococcus pneumoniae, through phosphorylation of several key proteins. Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ. We show that LocZ is a new cell division protein important for proper septum placement and likely functions as a marker of the cell division site. Consistently, LocZ supports proper Z-ring positioning at midcell. LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.

scholarly journals Role of the α-Glucanase Agn1p in Fission-Yeast Cell Separation

2004 ◽  
Vol 15 (8) ◽  
pp. 3903-3914 ◽  
Author(s):  
Nick Dekker ◽  
Dave Speijer ◽  
Christian H. Grün ◽  
Marlene van den Berg ◽  
Annett de Haan ◽  
...  
Keyword(s):  
Cell Division ◽  
Fission Yeast ◽  
Cell Separation ◽  
Wall Material ◽  
Dependent Manner ◽  
Cellular Functions ◽  
Daughter Cells ◽  
Primary Septum ◽  
Cycle Dependent ◽  
Division Cell

Cell division in the fission yeast Schizosaccharomyces pombe yields two equal-sized daughter cells. Medial fission is achieved by deposition of a primary septum flanked by two secondary septa within the dividing cell. During the final step of cell division, cell separation, the primary septum is hydrolyzed by an endo-(1,3)-β-glucanase, Eng1p. We reasoned that the cell wall material surrounding the septum, referred to here as the septum edging, also must be hydrolyzed before full separation of the daughter cells can occur. Because the septum edging contains (1,3)-α-glucan, we investigated the cellular functions of the putative (1,3)-α-glucanases Agn1p and Agn2p. Whereas agn2 deletion results in a defect in endolysis of the ascus wall, deletion of agn1 leads to clumped cells that remained attached to each other by septum-edging material. Purified Agn1p hydrolyzes (1,3)-α-glucan predominantly into pentasaccharides, indicating an endo-catalytic mode of hydrolysis. Furthermore, we show that the transcription factors Sep1p and Ace2p regulate both eng1 and agn1 expression in a cell cycle-dependent manner. We propose that Agn1p acts in concert with Eng1p to achieve efficient cell separation, thereby exposing the secondary septa as the new ends of the daughter cells.

scholarly journals Chromosome segregation drives division site selection inStreptococcus pneumoniae

2016 ◽  
Author(s):  
Renske van Raaphorst ◽  
Morten Kjos ◽  
Jan-Willem Veening
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Site Selection ◽  
Bacterial Cell Division ◽  
Division Plane ◽  
Canonical Systems ◽  
Daughter Cells ◽  
Division Site ◽  
Additional Protein ◽  
Site Control

AbstractAccurate spatial and temporal positioning of the tubulin-like protein FtsZ is key for proper bacterial cell division.Streptococcus pneumoniae(pneumococcus) is an oval-shaped, symmetrically dividing human pathogen lacking the canonical systems for division site control (nucleoid occlusion and the Min-system). Recently, the early division protein MapZ was identified and implicated in pneumococcal division site selection. We show that MapZ is important for proper division plane selection; thus the question remains what drives pneumococcal division site selection. By mapping the cell cycle in detail, we show that directly after replication both chromosomal origin regions localize to the future cell division sites, prior to FtsZ. Perturbing the longitudinal chromosomal organization by mutating the condensin SMC, by CRISPR/Cas9-mediated chromosome cutting or by poisoning DNA decatenation resulted in mistiming of MapZ and FtsZ positioning and subsequent cell elongation. Together, we demonstrate an intimate relationship between DNA replication, chromosome segregation and division site selection in the pneumococcus, providing a simple way to ensure equally sized daughter cells without the necessity for additional protein factors.

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 Chromokinesin KIF4A teams up with stathmin 1 to regulate abscission in a SUMO-dependent manner

2020 ◽  
Vol 133 (14) ◽  
pp. jcs248591
Author(s):  
Sabine A. G. Cuijpers ◽  
Edwin Willemstein ◽  
Jan G. Ruppert ◽  
Daphne M. van Elsland ◽  
William C. Earnshaw ◽  
...  
Keyword(s):  
Cell Division ◽  
Acceptor Site ◽  
Dependent Manner ◽  
Intercellular Bridge ◽  
Dynamic Interactions ◽  
Post Translational Modifications ◽  
Sumo Modification ◽  
Daughter Cells ◽  
Sumo Conjugation ◽  
Stathmin 1

ABSTRACTCell division ends when two daughter cells physically separate via abscission, the cleavage of the intercellular bridge. It is not clear how the anti-parallel microtubule bundles bridging daughter cells are severed. Here, we present a novel abscission mechanism. We identified chromokinesin KIF4A, which is adjacent to the midbody during cytokinesis, as being required for efficient abscission. KIF4A is regulated by post-translational modifications. We evaluated modification of KIF4A by the ubiquitin-like protein SUMO. We mapped lysine 460 in KIF4A as the SUMO acceptor site and employed CRISPR-Cas9-mediated genome editing to block SUMO conjugation of endogenous KIF4A. Failure to SUMOylate this site in KIF4A delayed cytokinesis. SUMOylation of KIF4A enhanced the affinity for the microtubule destabilizer stathmin 1 (STMN1). We here present a new level of abscission regulation through the dynamic interactions between KIF4A and STMN1 as controlled by SUMO modification of KIF4A.

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