scholarly journals Treadmilling by FtsZ filaments drives peptidoglycan synthesis and bacterial cell division

2016 ◽  
Author(s):  
Alexandre W. Bisson Filho ◽  
Yen-Pang Hsu ◽  
Georgia R. Squyres ◽  
Erkin Kuru ◽  
Fabai Wu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Division ◽  
Division Ring ◽  
Bacterial Cell ◽  
Cytoplasmic Membrane ◽  
Bacterial Cell Division ◽  
Cell Wall Synthesis ◽  
Division Plane ◽  
Peptidoglycan Synthesis

AbstractHow bacteria produce a septum to divide in two is not well understood. This process is mediated by periplasmic cell-wall producing enzymes that are positioned by filaments of the cytoplasmic membrane-associated actin FtsA and the tubulin FtsZ (FtsAZ). To understand how these components act in concert to divide cells, we visualized their movements relative to the dynamics of cell wall synthesis during cytokinesis. We find that the division septum is built at discrete sites that move around the division plane. Furthermore, FtsAZ filaments treadmill in circumferential paths around the division ring, pulling along the associated cell-wall-synthesizing enzymes. We show that the rate of FtsZ treadmilling controls both the rate of cell wall synthesis and cell division. The coupling of both the position and activity of the cell wall synthases to FtsAZ treadmilling guides the progressive insertion of new cell wall, synthesizing increasingly small concentric rings to divide the cell.One-sentence summaryBacterial cytokinesis is controlled by circumferential treadmilling of FtsAZ filaments that drives the insertion of new cell wall.

scholarly journals Asymmetric localization of the cell division machinery during Bacillus subtilis sporulation

2020 ◽  
Author(s):  
Kanika Khanna ◽  
Javier López-Garrido ◽  
Joseph Sugie ◽  
Kit Pogliano ◽  
Elizabeth Villa
Keyword(s):  
Bacillus Subtilis ◽  
Cell Division ◽  
Vegetative Growth ◽  
Bacterial Cell ◽  
Mother Cell ◽  
Electron Tomography ◽  
Leading Edge ◽  
Specific Protein ◽  
Bacterial Cell Division ◽  
Division Plane

The mechanistic details of bacterial cell division are poorly understood. The Gram-positive bacterium Bacillus subtilis can divide via two modes. During vegetative growth, the division septum is formed at the mid cell to produce two equal daughter cells. However, during sporulation, the division septum is formed closer to one pole to yield a smaller forespore and a larger mother cell. We use cryo-electron tomography to visualize the architectural differences in the organization of FtsAZ filaments, the major orchestrators of bacterial cell division during these conditions. We demonstrate that during vegetative growth, FtsAZ filaments are present uniformly around the leading edge of the invaginating septum but during sporulation, they are only present on the mother cell side. Our data show that the sporulation septum is thinner than the vegetative septum during constriction, and that this correlates with half as many FtsZ filaments tracking the division plane during sporulation as compared to vegetative growth. We further find that a sporulation-specific protein, SpoIIE, regulates divisome localization and septal thickness during sporulation. Our data provide first evidence of asymmetric localization of the cell division machinery, and not just septum formation, to produce different cell types with diverse fates in bacteria.

scholarly journals DivIVA Is Required for Polar Growth in the MreB-Lacking Rod-Shaped Actinomycete Corynebacterium glutamicum

2008 ◽  
Vol 190 (9) ◽  
pp. 3283-3292 ◽  
Author(s):  
Michal Letek ◽  
Efrén Ordóñez ◽  
José Vaquera ◽  
William Margolin ◽  
Klas Flärdh ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Division ◽  
Streptococcus Pneumoniae ◽  
Corynebacterium Glutamicum ◽  
Chromosome Segregation ◽  
Polar Growth ◽  
Cell Wall Synthesis ◽  
Peptidoglycan Synthesis ◽  
Polarized Cell Growth

ABSTRACT The actinomycete Corynebacterium glutamicum grows as rod-shaped cells by zonal peptidoglycan synthesis at the cell poles. In this bacterium, experimental depletion of the polar DivIVA protein (DivIVACg) resulted in the inhibition of polar growth; consequently, these cells exhibited a coccoid morphology. This result demonstrated that DivIVA is required for cell elongation and the acquisition of a rod shape. DivIVA from Streptomyces or Mycobacterium localized to the cell poles of DivIVACg-depleted C. glutamicum and restored polar peptidoglycan synthesis, in contrast to DivIVA proteins from Bacillus subtilis or Streptococcus pneumoniae, which localized at the septum of C. glutamicum. This confirmed that DivIVAs from actinomycetes are involved in polarized cell growth. DivIVACg localized at the septum after cell wall synthesis had started and the nucleoids had already segregated, suggesting that in C. glutamicum DivIVA is not involved in cell division or chromosome segregation.

scholarly journals A conserved subcomplex within the bacterial cytokinetic ring activates cell wall synthesis by the FtsW-FtsI synthase

2020 ◽  
Vol 117 (38) ◽  
pp. 23879-23885 ◽  
Author(s):  
Lindsey S. Marmont ◽  
Thomas G. Bernhardt
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Wall ◽  
Cell Division ◽  
Polymerase Activity ◽  
Bacterial Cell Division ◽  
Cell Wall Synthesis ◽  
Negative Regulators ◽  
Major Function ◽  
Osmotic Lysis ◽  
Direct Activator

Cell division in bacteria is mediated by a multiprotein assembly called the divisome. A major function of this machinery is the synthesis of the peptidoglycan (PG) cell wall that caps the daughter poles and prevents osmotic lysis of the newborn cells. Recent studies have implicated a complex of FtsW and FtsI (FtsWI) as the essential PG synthase within the divisome; however, how PG polymerization by this synthase is regulated and coordinated with other activities within the machinery is not well understood. Previous results have implicated a conserved subcomplex of division proteins composed of FtsQ, FtsL, and FtsB (FtsQLB) in the regulation of FtsWI, but whether these proteins act directly as positive or negative regulators of the synthase has been unclear. To address this question, we purified a five-memberPseudomonas aeruginosadivision complex consisting of FtsQLB-FtsWI. The PG polymerase activity of this complex was found to be greatly stimulated relative to FtsWI alone. Purification of complexes lacking individual components indicated that FtsL and FtsB are sufficient for FtsW activation. Furthermore, support for this activity being important for the cellular function of FtsQLB was provided by the identification of two division-defective variants of FtsL that still form normal FtsQLB-FtsWI complexes but fail to activate PG synthesis. Thus, our results indicate that the conserved FtsQLB complex is a direct activator of PG polymerization by the FtsWI synthase and thereby define an essential regulatory step in the process of bacterial cell division.

scholarly journals Treadmilling by FtsZ filaments drives peptidoglycan synthesis and bacterial cell division

Science ◽  
2017 ◽  
Vol 355 (6326) ◽  
pp. 739-743 ◽  
Author(s):  
Alexandre W. Bisson-Filho ◽  
Yen-Pang Hsu ◽  
Georgia R. Squyres ◽  
Erkin Kuru ◽  
Fabai Wu ◽  
...  
Keyword(s):  
Cell Division ◽  
Bacterial Cell ◽  
Bacterial Cell Division ◽  
Peptidoglycan Synthesis

Aerosol survival of Serratia marcescens as a function of oxygen concentration, relative humidity, and time

1974 ◽  
Vol 20 (11) ◽  
pp. 1529-1534 ◽  
Author(s):  
C. S. Cox ◽  
S. J. Gagen ◽  
Jean Baxter
Keyword(s):  
Cell Wall ◽  
Cell Division ◽  
Relative Humidity ◽  
Serratia Marcescens ◽  
Oxygen Concentration ◽  
Freeze Drying ◽  
Cytoplasmic Membrane ◽  
Cell Wall Synthesis ◽  
Freeze Dried ◽  
Kinetics Of

Previously the kinetics of loss of viability of freeze-dried Serratia marcescens 8UK were determined by Cox and Heckly as a function of oxygen concentration and time. Results are presented here when dehydration is brought about by aerosolization into atmospheres of low relative humidity (RH) rather than by freeze-drying. As for freeze-dried S. marcescens, oxygen was toxic and viable decay followed the same kinetics with respect to oxygen concentration and time. The influence of RH upon viable decay (which was not studied in the previous report) was that above 65% RH oxygen was not toxic but was progressively more toxic as the humidity was further reduced. Kinetic analyses of the results indicate that the site for the toxic action of oxygen lies in the interspace between the cytoplasmic membrane and the cell wall. Such a finding is consistent with other data which suggest that cell division and (or) cell wall synthesis in bacteria are inhibited by oxygen.

scholarly journals SmdA is a novel cell morphology determinant in Staphylococcus aureus

2021 ◽  
Author(s):  
Ine Storaker Myrbråten ◽  
Gro A. Stamsås ◽  
Helena Chan ◽  
Danae Morales Angeles ◽  
Tiril Mathiesen Knutsen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Division ◽  
Cell Morphology ◽  
Spherical Shape ◽  
Major Influence ◽  
Cell Wall Synthesis ◽  
Division Plane ◽  
Microscopy Techniques ◽  
Two Hybrid

Cell division and cell wall synthesis in staphylococci need to be precisely coordinated and controlled to allow the cell to multiply while maintaining their nearly spherical shape. The mechanisms ensuring correct placement of the division plane and synthesis of new cell wall have been studied intensively, however, hitherto unknown factors and proteins are likely to play key roles in this complex interplay. Starting from a subcellular localization- and gene knockdown screen of essential genes with unknown functions in Staphylococcus aureus, we identified a protein with major influence on cell morphology in S. aureus. The protein, here named SmdA (for staphylococcal morphology determinant A), is a membrane-protein with septum-enriched localization. By smdA silencing and overexpression, we have used different microscopy techniques to show that SmdA is critical for cell division, including septum formation and cell splitting. We also identified conserved residues in SmdA that are critical for functionality. Pulldown- and bacterial two-hybrid interaction experiments showed that SmdA interacts with several known cell division- and cell wall synthesis proteins, including penicillin binding proteins (PBPs) and EzrA. Notably, SmdA also affects susceptibility to cell wall targeting antibiotics, particularly in methicillin-resistant S. aureus (MRSA). Together, our results show that S. aureus is dependent on balanced amounts of membrane-attached SmdA in order to carry out proper cell division.

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