Membrane fission during bacterial spore development requires DNA-driven cellular inflation

Bacteria require membrane fission for cell division and endospore formation. FisB catalyzes membrane fission during sporulation, but the molecular basis is unclear as it cannot remodel membranes by itself. Sporulation initiates with an asymmetric division that generates a large mother cell and a smaller forespore that contains only 1/4 of its complete genome. As the mother cell membranes engulf the forespore, a DNA translocase pumps the rest of the chromosome into the small forespore compartment, inflating it due to increased turgor. When the engulfing membranes undergo fission, the forespore is released into the mother cell cytoplasm. Here we show that forespore inflation and FisB accumulation are both required for efficient membrane fission. We suggest that high membrane tension in the engulfment membrane caused by forespore inflation drives FisB-catalyzed membrane fission. Collectively our data indicate that DNA-translocation has a previously unappreciated second function in energizing FisB-mediated membrane fission under energy-limited conditions.

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Postdivisional Synthesis of the Sporosarcina ureae DNA Translocase SpoIIIE either in the Mother Cell or in the Prespore Enables Bacillus subtilis To Translocate DNA from the Mother Cell to the Prespore

Journal of Bacteriology ◽

10.1128/jb.185.3.879-886.2003 ◽

2003 ◽

Vol 185 (3) ◽

pp. 879-886 ◽

Cited By ~ 11

Author(s):

Vasant K. Chary ◽

Patrick J. Piggot

Keyword(s):

Bacillus Subtilis ◽

Cell Division ◽

Mother Cell ◽

Asymmetric Cell Division ◽

Dna Translocation ◽

Sporosarcina Ureae ◽

Correct Orientation ◽

Chromosome Partitioning ◽

Specific Synthesis ◽

Dna Translocase

ABSTRACT The differentiation of vegetative cells of Bacillus subtilis into spores involves asymmetric cell division, which precedes complete chromosome partitioning. The DNA translocase SpoIIIE is required to translocate the origin distal 70% of the chromosome from the larger mother cell into the smaller prespore, the two cells that result from the division. We have tested the effect of altering the time and location of SpoIIIE synthesis on spore formation. We have expressed the spoIIIE homologue from Sporosarcina ureae in B. subtilis under the control of different promoters. Expression from either a weak mother cell-specific (σE) promoter or a weak prespore-specific (σF) promoter partly complemented the sporulation defect of a spoIIIE36 mutant; however, expression from a strong prespore-specific (σF) promoter did not. DNA translocation from the mother cell to the prespore was assayed using spoIIQ-lacZ inserted at thrC; transcription of spoIIQ occurs only in the prespore. Translocation of thrC::spoIIQ-lacZ into the prespore occurred efficiently when spoIIIE Su was expressed from the weak σE- or σF-controlled promoters but not when it was expressed from the strong σF-controlled promoter. It is speculated that the mechanism directing SpoIIIE insertion into the septum in the correct orientation may accommodate slow postseptational, prespore-specific SpoIIIE synthesis but may be swamped by strong prespore-specific synthesis.

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Visualization and functional dissection of coaxial paired SpoIIIE channels across the sporulation septum

eLife ◽

10.7554/elife.06474 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 25

Author(s):

Jae Yen Shin ◽

Javier Lopez-Garrido ◽

Sang-Hyuk Lee ◽

Cesar Diaz-Celis ◽

Tinya Fleming ◽

...

Keyword(s):

Protein Degradation ◽

Mother Cell ◽

Chromosome Translocation ◽

Specific Protein ◽

Dna Translocation ◽

Membrane Fission ◽

Photoactivated Localization Microscopy ◽

And Function ◽

Dna Translocase

SpoIIIE is a membrane-anchored DNA translocase that localizes to the septal midpoint to mediate chromosome translocation and membrane fission during Bacillus subtilis sporulation. Here we use cell-specific protein degradation and quantitative photoactivated localization microscopy in strains with a thick sporulation septum to investigate the architecture and function of the SpoIIIE DNA translocation complex in vivo. We were able to visualize SpoIIIE complexes with approximately equal numbers of molecules in the mother cell and the forespore. Cell-specific protein degradation showed that only the mother cell complex is required to translocate DNA into the forespore, whereas degradation in either cell reverses membrane fission. Our data suggest that SpoIIIE assembles a coaxially paired channel for each chromosome arm comprised of one hexamer in each cell to maintain membrane fission during DNA translocation. We show that SpoIIIE can operate, in principle, as a bi-directional motor that exports DNA.

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FisB relies on homo-oligomerization and lipid binding to catalyze membrane fission in bacteria

PLoS Biology ◽

10.1371/journal.pbio.3001314 ◽

2021 ◽

Vol 19 (6) ◽

pp. e3001314

Author(s):

Ane Landajuela ◽

Martha Braun ◽

Christopher D. A. Rodrigues ◽

Alejandro Martínez-Calvo ◽

Thierry Doan ◽

...

Keyword(s):

Bacillus Subtilis ◽

Mother Cell ◽

Negative Curvature ◽

Lipid Binding ◽

Membrane Curvature ◽

Membrane Topology ◽

Cell Cytoplasm ◽

Curvature Sensing ◽

Membrane Fission ◽

Late Stages

Little is known about mechanisms of membrane fission in bacteria despite their requirement for cytokinesis. The only known dedicated membrane fission machinery in bacteria, fission protein B (FisB), is expressed during sporulation in Bacillus subtilis and is required to release the developing spore into the mother cell cytoplasm. Here, we characterized the requirements for FisB-mediated membrane fission. FisB forms mobile clusters of approximately 12 molecules that give way to an immobile cluster at the engulfment pole containing approximately 40 proteins at the time of membrane fission. Analysis of FisB mutants revealed that binding to acidic lipids and homo-oligomerization are both critical for targeting FisB to the engulfment pole and membrane fission. Experiments using artificial membranes and filamentous cells suggest that FisB does not have an intrinsic ability to sense or induce membrane curvature but can bridge membranes. Finally, modeling suggests that homo-oligomerization and trans-interactions with membranes are sufficient to explain FisB accumulation at the membrane neck that connects the engulfment membrane to the rest of the mother cell membrane during late stages of engulfment. Together, our results show that FisB is a robust and unusual membrane fission protein that relies on homo-oligomerization, lipid binding, and the unique membrane topology generated during engulfment for localization and membrane scission, but surprisingly, not on lipid microdomains, negative-curvature lipids, or curvature sensing.

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The bacterial membrane fission protein FisB requires homo-oligomerization and lipid-binding to catalyze membrane scission

10.1101/2020.09.25.313023 ◽

2020 ◽

Author(s):

Ane Landajuela ◽

Martha Braun ◽

Christopher D. A. Rodrigues ◽

Thierry Doan ◽

Florian Horenkamp ◽

...

Keyword(s):

Bacillus Subtilis ◽

Mother Cell ◽

Negative Curvature ◽

Lipid Binding ◽

Membrane Topology ◽

Bacterial Membrane ◽

Cell Cytoplasm ◽

Lipid Microdomains ◽

Membrane Fission ◽

Membrane Scission

ABSTRACTLittle is known about mechanisms of membrane fission in bacteria despite their requirement for cytokinesis. The only known dedicated membrane fission machinery in bacteria, FisB, is expressed during sporulation in Bacillus subtilis and is required to release the developing spore into the mother cell cytoplasm. Here we characterized the requirements for FisB-mediated membrane fission. FisB forms mobile clusters of ~12 molecules that give way to an immobile cluster at the engulfment pole containing ~40 proteins at the time of membrane fission. Function mutants revealed that binding to acidic lipids and homo-oligomerization are both critical for targeting FisB to the engulfment pole and membrane fission. Our results suggest that FisB is a robust and unusual membrane fission protein that relies on homo-oligomerization, lipid-binding and likely the unique membrane topology generated during engulfment for localization and membrane scission, but surprisingly, not on lipid microdomains or negative-curvature lipids.

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Cell grouping and primary wall generations in the cambial zone, xylem, and phloem in Pinus

Australian Journal of Botany ◽

10.1071/bt9680177 ◽

1968 ◽

Vol 16 (2) ◽

pp. 177 ◽

Cited By ~ 17

Author(s):

A Mahmood

Keyword(s):

Cell Division ◽

Mother Cell ◽

Secondary Wall ◽

Radial Direction ◽

Cell Plate ◽

Tangential Direction ◽

Primary Wall ◽

Photographic Evidence ◽

Secondary Wall Deposition ◽

Cambial Zone

The use of the term cambium, or equivalent terms, in modern literature is discussed. The term cambial zone adopted in this paper includes the cambial initial and the dividing and enlarging cells. The tissue mother cell produced at each division of the initial produces a group of four cells in xylem or two cells in phloem. Theoretical constructs have been made for xylem and phloem production by associating the concepts that xylem and phloem are produced in alternate series of initial divisions and that a new primary wall is deposited around each daughter protoplast at each cell division. Correlations are derived from the theoretical constructs for the thickness of primary wall layers lying in the tangential direction and of those lying in the radial direction at progressive histological levels. Deductions from theoretical constructs are made when the initial is producing xylem, when it changes its polarity from xylem to phloem production, and when the reverse change occurs. Most of the theoretical deductions are supported by photographic evidence. The chief point of this study is the demonstration of generations (multiplicity) of primary parental walls. The term intercellular material proposed in this paper includes the cell plate plus any remnants of ancestral primary walls between the current primary walls surrounding the adjacent protoplasts. This term is still applicable to cells where secondary wall deposition is taking place or has been completed.

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Cell-Division of the Pollen-Mother-Cell of Cobaea scandens Alba

Bulletin of the Torrey Botanical Club ◽

10.2307/2480256 ◽

1920 ◽

Vol 47 (8) ◽

pp. 325 ◽

Cited By ~ 5

Author(s):

Wanda Kirkbride Farr

Keyword(s):

Cell Division ◽

Pollen Mother Cell ◽

Mother Cell

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c-di-GMP heterogeneity is generated by the chemotaxis machinery to regulate flagellar motility

eLife ◽

10.7554/elife.01402 ◽

2013 ◽

Vol 2 ◽

Cited By ~ 68

Author(s):

Bridget R Kulasekara ◽

Cassandra Kamischke ◽

Hemantha D Kulasekara ◽

Matthias Christen ◽

Paul A Wiggins ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Cell Division ◽

Histidine Kinase ◽

Molecular Basis ◽

Individual Cell ◽

Cell Heterogeneity ◽

Flagellar Motility ◽

Bacterial Populations ◽

Phosphorylation State ◽

Asymmetric Partitioning

Individual cell heterogeneity is commonly observed within populations, although its molecular basis is largely unknown. Previously, using FRET-based microscopy, we observed heterogeneity in cellular c-di-GMP levels. In this study, we show that c-di-GMP heterogeneity in Pseudomonas aeruginosa is promoted by a specific phosphodiesterase partitioned after cell division. We found that subcellular localization and reduction of c-di-GMP levels by this phosphodiesterase is dependent on the histidine kinase component of the chemotaxis machinery, CheA, and its phosphorylation state. Therefore, individual cell heterogeneity in c-di-GMP concentrations is regulated by the activity and the asymmetrical inheritance of the chemotaxis organelle after cell division. c-di-GMP heterogeneity results in a diversity of motility behaviors. The generation of diverse intracellular concentrations of c-di-GMP by asymmetric partitioning is likely important to the success and survival of bacterial populations within the environment by allowing a variety of motility behaviors.

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Meiotic Chromosome Behavior and Capsule Setting in Doritaenopsis Hybrids

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.133.1.107 ◽

2008 ◽

Vol 133 (1) ◽

pp. 107-116 ◽

Cited By ~ 5

Author(s):

Pablo Bolaños-Villegas ◽

Shih-Wen Chin ◽

Fure-Chyi Chen

Keyword(s):

Cell Division ◽

Pollen Mother Cell ◽

Chromosome Pairing ◽

Chromosomal Aberrations ◽

High Frequency ◽

Mother Cell ◽

Seed Set ◽

Pollen Viability ◽

High Pollen ◽

Mother Cells

The development of new cultivars in Doritaenopsis Guillaum. & Lami orchids is often hindered by factors such as low seed count in hybrids. Cytological study may offer the ability to develop new hybrids by revealing cultivars with good chromosome pairing and high pollen viability, which are somewhat difficult to obtain under current breeding programs. Cross pollination, pollen viability, and chromosomal behavior during meiosis were analyzed to reveal the relation between seed fertility and capsule set in Doritaenopsis hybrids. The number of mature capsules harvested and their relative seed content were used as indices of crossing availability. The results of meiosis were evaluated according to pollen viability detected by fluorescein diacetate and quantification of sporad types by acid fuchsin staining. Chromosome number and pairing at meiosis were observed in root tips or in samples of pollen mother cells. A positive relation was found among high seed set, high frequency of viable tetrads, high degree of chromosome pairing, and low frequency of chromosomal aberrations such as inversions and translocations. On the basis of these factors, three types of hybrids could be distinguished. In type one hybrids, chromosomes paired as bivalents, pollen mother cells divided into tetrads, and capsule setting occurred after pollination of pollen acceptors. In type two hybrids, chromosomes remained mainly as univalents that developed into micromeiocytes, pollen mother cell division was disrupted, and seed recovery was low after pollination. Type three hybrids showed chromosomes paired mostly as multivalents, chromosome bridges, pollen mother cell division with massive failure, and little fertility. In Doritaenopsis orchids, high pollen viability and high fertility depends on a high frequency of normal tetrads, and low seed set in cross-pollination is predicted with micronuclei in the end products of meiosis. The occurrence of chromosomal aberrations may suggest a process of genome differentiation that could compromise breeding efforts if not taken into consideration.

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