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Krusenstjerna AC, Jusufovic N, Saylor TC, Stevenson B. DnaA modulates the gene expression and morphology of the Lyme disease spirochete. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.598065. [PMID: 38895450 PMCID: PMC11185795 DOI: 10.1101/2024.06.08.598065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
All bacteria encode a multifunctional DNA-binding protein, DnaA, which initiates chromosomal replication. Despite having the most complex, segmented bacterial genome, little is known about Borrelia burgdorferi DnaA and its role in maintaining the spirochete's physiology. In this work we utilized inducible CRISPR-interference and overexpression to modulate cellular levels of DnaA to better understand this essential protein. Dysregulation of DnaA, either up or down, increased or decreased cell lengths, respectively, while also significantly slowing replication rates. Using fluorescent microscopy, we found the DnaA CRISPRi mutants had increased numbers of chromosomes with irregular spacing patterns. DnaA-depleted spirochetes also exhibited a significant defect in helical morphology. RNA-seq of the conditional mutants showed significant changes in the levels of transcripts involved with flagellar synthesis, elongation, cell division, virulence, and other functions. These findings demonstrate that the DnaA plays a commanding role in maintaining borrelial growth dynamics and protein expression, which are essential for the survival of the Lyme disease spirochete. IMPORTANCE Lyme disease is the most prevalent tick-borne infection in the Northern Hemisphere. Borrelia burgdorferi , the causative spirochete bacteria, has been maintained in nature for millennia in a consistent enzootic cycle between Ixodes ticks and various small vertebrate hosts. During the tick's blood meal, B. burgdorferi substantially increases its replication rate, alters its repertoire of outer surface proteins, and disseminates into the new vertebrate host. Across eubacteria, DnaA is the master regulatory protein that initiates chromosomal replication and acts as a transcription factor to regulate specific pathways. Here, we describe the roles that B. burgdorferi DnaA has on the physiology and gene expression of this medically important pathogen.
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2
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Perkins A, Mounange-Badimi MS, Margolin W. Role of the antiparallel double-stranded filament form of FtsA in activating the Escherichia coli divisome. mBio 2024; 15:e0168724. [PMID: 39041810 PMCID: PMC11323482 DOI: 10.1128/mbio.01687-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Accepted: 06/28/2024] [Indexed: 07/24/2024] Open
Abstract
The actin-like FtsA protein is essential for function of the cell division machinery, or divisome, in many bacteria including Escherichia coli. Previous in vitro studies demonstrated that purified wild-type FtsA assembles into closed mini-rings on lipid membranes, but oligomeric variants of FtsA such as FtsAR286W and FtsAG50E can bypass certain divisome defects and form arc and double-stranded (DS) oligomeric states, respectively, which may reflect conversion of an inactive to an active form of FtsA. However, it remains unproven which oligomeric forms of FtsA are responsible for assembling and activating the divisome. Here, we used an in vivo crosslinking assay for FtsA DS filaments to show that they largely depend on proper divisome assembly and are prevalent at later stages of cell division. We also used a previously reported variant that fails to assemble DS filaments, FtsAM96E R153D, to investigate the roles of FtsA oligomeric states in divisome assembly and activation. We show that FtsAM96E R153D cannot form DS filaments in vivo, fails to replace native FtsA, and confers a dominant negative phenotype, underscoring the importance of the DS filament stage for FtsA function. Surprisingly, however, activation of the divisome through the ftsL* or ftsW* superfission alleles suppressed the dominant negative phenotype and rescued the functionality of FtsAM96E R153D. Our results suggest that FtsA DS filaments are needed for divisome activation once it is assembled, but they are not essential for divisome assembly or guiding septum synthesis.IMPORTANCECell division is fundamental for cellular duplication. In simple cells like Escherichia coli bacteria, the actin homolog FtsA is essential for cell division and assembles into a variety of protein filaments at the cytoplasmic membrane. These filaments not only help tether polymers of the tubulin-like FtsZ to the membrane at early stages of cell division but also play crucial roles in recruiting other cell division proteins to a complex called the divisome. Once assembled, the E. coli divisome subsequently activates synthesis of the division septum that splits the cell in two. One recently discovered oligomeric conformation of FtsA is an antiparallel double-stranded filament. Using a combination of in vivo crosslinking and genetics, we provide evidence suggesting that these FtsA double filaments have a crucial role in activating the septum synthesis enzymes.
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Affiliation(s)
- Abbigale Perkins
- Department of Microbiology and Molecular Genetics, UTHealth Houston McGovern Medical School, Houston, Texas, USA
| | - Mwidy Sava Mounange-Badimi
- Department of Microbiology and Molecular Genetics, UTHealth Houston McGovern Medical School, Houston, Texas, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, UTHealth Houston McGovern Medical School, Houston, Texas, USA
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3
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Perkins A, Mounange-Badimi MS, Margolin W. Role of the antiparallel double-stranded filament form of FtsA in activating the Escherichia coli divisome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.24.600433. [PMID: 38979378 PMCID: PMC11230281 DOI: 10.1101/2024.06.24.600433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The actin-like FtsA protein is essential for function of the cell division machinery, or divisome, in many bacteria including Escherichia coli. Previous in vitro studies demonstrated that purified wild-type FtsA assembles into closed mini-rings on lipid membranes, but oligomeric variants of FtsA such as FtsAR286W and FtsAG50E can bypass certain divisome defects and form arc and double-stranded (DS) oligomeric states, respectively, which may reflect conversion of an inactive to an active form of FtsA. Yet, it remains unproven which oligomeric forms of FtsA are responsible for assembling and activating the divisome. Here we used an in vivo crosslinking assay for FtsA DS filaments to show that they largely depend on proper divisome assembly and are prevalent at later stages of cell division. We also used a previously reported variant that fails to assemble DS filaments, FtsAM96E R153D, to investigate the roles of FtsA oligomeric states in divisome assembly and activation. We show that FtsAM96E R153D cannot form DS filaments in vivo, fails to replace native FtsA, and confers a dominant negative phenotype, underscoring the importance of the DS filament stage for FtsA function. Surprisingly, however, activation of the divisome through the ftsL* or ftsW* superfission alleles suppressed the dominant negative phenotype and rescued the functionallity of FtsAM96E R153D. Our results suggest that FtsA DS filaments are needed for divisome activation once it is assembled, but they are not essential for divisome assembly or guiding septum synthesis.
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Affiliation(s)
- Abbigale Perkins
- Microbiology and Molecular Genetics, UTHealth McGovern Medical School, 6431 Fannin Street, Houston, TX 77030
| | - Mwidy Sava Mounange-Badimi
- Microbiology and Molecular Genetics, UTHealth McGovern Medical School, 6431 Fannin Street, Houston, TX 77030
| | - William Margolin
- Microbiology and Molecular Genetics, UTHealth McGovern Medical School, 6431 Fannin Street, Houston, TX 77030
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4
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Radler P, Loose M. A dynamic duo: Understanding the roles of FtsZ and FtsA for Escherichia coli cell division through in vitro approaches. Eur J Cell Biol 2024; 103:151380. [PMID: 38218128 DOI: 10.1016/j.ejcb.2023.151380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/15/2024] Open
Abstract
Bacteria divide by binary fission. The protein machine responsible for this process is the divisome, a transient assembly of more than 30 proteins in and on the surface of the cytoplasmic membrane. Together, they constrict the cell envelope and remodel the peptidoglycan layer to eventually split the cell into two. For Escherichia coli, most molecular players involved in this process have probably been identified, but obtaining the quantitative information needed for a mechanistic understanding can often not be achieved from experiments in vivo alone. Since the discovery of the Z-ring more than 30 years ago, in vitro reconstitution experiments have been crucial to shed light on molecular processes normally hidden in the complex environment of the living cell. In this review, we summarize how rebuilding the divisome from purified components - or at least parts of it - have been instrumental to obtain the detailed mechanistic understanding of the bacterial cell division machinery that we have today.
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Affiliation(s)
- Philipp Radler
- Institute for Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria; University of Vienna, Djerassiplatz 1, 1030 Wien, Austria.
| | - Martin Loose
- Institute for Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria.
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5
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Santiago-Collazo G, Brown PJB, Randich AM. The divergent early divisome: is there a functional core? Trends Microbiol 2024; 32:231-240. [PMID: 37741788 DOI: 10.1016/j.tim.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/25/2023]
Abstract
The bacterial divisome is a complex nanomachine that drives cell division and separation. The essentiality of these processes leads to the assumption that proteins with core roles will be strictly conserved across all bacterial genomes. However, recent studies in diverse proteobacteria have revealed considerable variation in the early divisome compared with Escherichia coli. While some proteins are highly conserved, their specific functions and interacting partners vary. Meanwhile, different subphyla use clade-specific proteins with analogous functions. Thus, instead of focusing on gene conservation, we must also explore how key functions are maintained during early division by diverging protein networks. An enhanced awareness of these complex genetic networks will clarify the physical and evolutionary constraints of bacterial division.
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Affiliation(s)
- Gustavo Santiago-Collazo
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri-Columbia, Columbia, MO, USA
| | - Pamela J B Brown
- Division of Biological Sciences, College of Arts and Sciences, University of Missouri-Columbia, Columbia, MO, USA
| | - Amelia M Randich
- Department of Biology, College of Arts and Sciences, University of Scranton, Scranton, PA, USA.
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6
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Cramer K, Reinhardt SCM, Auer A, Shin JY, Jungmann R. Comparing divisome organization between vegetative and sporulating Bacillus subtilis at the nanoscale using DNA-PAINT. SCIENCE ADVANCES 2024; 10:eadk5847. [PMID: 38198550 PMCID: PMC10780868 DOI: 10.1126/sciadv.adk5847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/11/2023] [Indexed: 01/12/2024]
Abstract
Spore-forming bacteria have two distinct division modes: sporulation and vegetative division. The placement of the foundational division machinery component (Z-ring) within the division plane is contingent on the division mode. However, investigating if and how division is performed differently between sporulating and vegetative cells remains challenging, particularly at the nanoscale. Here, we use DNA-PAINT super-resolution microscopy to compare the 3D assembly and distribution patterns of key division proteins SepF, ZapA, DivIVA, and FtsZ. We determine that ZapA and SepF placement within the division plane mimics that of the Z-ring in vegetative and sporulating cells. We find that DivIVA assemblies differ between vegetative and sporulating cells. Furthermore, we reveal that SepF assembles into ~50-nm arcs independent of division mode. We propose a nanoscale model in which symmetric or asymmetric placement of the Z-ring and early divisome proteins is a defining characteristic of vegetative or sporulating cells, respectively, and regulation of septal thickness differs between division modes.
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Affiliation(s)
- Kimberly Cramer
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Susanne C. M. Reinhardt
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Alexander Auer
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Jae Yen Shin
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
| | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian University, Munich, Germany
- Max Planck Institute of Biochemistry, Martinsried, Germany
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7
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Morrison JJ, Camberg JL. Building the Bacterial Divisome at the Septum. Subcell Biochem 2024; 104:49-71. [PMID: 38963483 DOI: 10.1007/978-3-031-58843-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Across living organisms, division is necessary for cell survival and passing heritable information to the next generation. For this reason, cell division is highly conserved among eukaryotes and prokaryotes. Among the most highly conserved cell division proteins in eukaryotes are tubulin and actin. Tubulin polymerizes to form microtubules, which assemble into cytoskeletal structures in eukaryotes, such as the mitotic spindle that pulls chromatids apart during mitosis. Actin polymerizes to form a morphological framework for the eukaryotic cell, or cytoskeleton, that undergoes reorganization during mitosis. In prokaryotes, two of the most highly conserved cell division proteins are the tubulin homolog FtsZ and the actin homolog FtsA. In this chapter, the functions of the essential bacterial cell division proteins FtsZ and FtsA and their roles in assembly of the divisome at the septum, the site of cell division, will be discussed. In most bacteria, including Escherichia coli, the tubulin homolog FtsZ polymerizes at midcell, and this step is crucial for recruitment of many other proteins to the division site. For this reason, both FtsZ abundance and polymerization are tightly regulated by a variety of proteins. The actin-like FtsA protein polymerizes and tethers FtsZ polymers to the cytoplasmic membrane. Additionally, FtsA interacts with later stage cell division proteins, which are essential for division and for building the new cell wall at the septum. Recent studies have investigated how actin-like polymerization of FtsA on the lipid membrane may impact division, and we will discuss this and other ways that division in bacteria is regulated through FtsZ and FtsA.
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Affiliation(s)
- Josiah J Morrison
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, USA
| | - Jodi L Camberg
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, USA.
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8
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Cameron TA, Margolin W. Insights into the assembly and regulation of the bacterial divisome. Nat Rev Microbiol 2024; 22:33-45. [PMID: 37524757 PMCID: PMC11102604 DOI: 10.1038/s41579-023-00942-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2023] [Indexed: 08/02/2023]
Abstract
The ability to split one cell into two is fundamental to all life, and many bacteria can accomplish this feat several times per hour with high accuracy. Most bacteria call on an ancient homologue of tubulin, called FtsZ, to localize and organize the cell division machinery, the divisome, into a ring-like structure at the cell midpoint. The divisome includes numerous other proteins, often including an actin homologue (FtsA), that interact with each other at the cytoplasmic membrane. Once assembled, the protein complexes that comprise the dynamic divisome coordinate membrane constriction with synthesis of a division septum, but only after overcoming checkpoints mediated by specialized protein-protein interactions. In this Review, we summarize the most recent evidence showing how the divisome proteins of Escherichia coli assemble at the cell midpoint, interact with each other and regulate activation of septum synthesis. We also briefly discuss the potential of divisome proteins as novel antibiotic targets.
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Affiliation(s)
- Todd A Cameron
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, USA.
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9
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Allgood SC, Su CC, Crooks AL, Meyer CT, Zhou B, Betterton MD, Barbachyn MR, Yu EW, Detweiler CS. Bacterial efflux pump modulators prevent bacterial growth in macrophages and under broth conditions that mimic the host environment. mBio 2023; 14:e0249223. [PMID: 37921493 PMCID: PMC10746280 DOI: 10.1128/mbio.02492-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 11/04/2023] Open
Abstract
IMPORTANCE Bacterial efflux pumps are critical for resistance to antibiotics and for virulence. We previously identified small molecules that inhibit efflux pumps (efflux pump modulators, EPMs) and prevent pathogen replication in host cells. Here, we used medicinal chemistry to increase the activity of the EPMs against pathogens in cells into the nanomolar range. We show by cryo-electron microscopy that these EPMs bind an efflux pump subunit. In broth culture, the EPMs increase the potency (activity), but not the efficacy (maximum effect), of antibiotics. We also found that bacterial exposure to the EPMs appear to enable the accumulation of a toxic metabolite that would otherwise be exported by efflux pumps. Thus, inhibitors of bacterial efflux pumps could interfere with infection not only by potentiating antibiotics, but also by allowing toxic waste products to accumulate within bacteria, providing an explanation for why efflux pumps are needed for virulence in the absence of antibiotics.
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Affiliation(s)
- Samual C. Allgood
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Amy L. Crooks
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Christian T. Meyer
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
- Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado, USA
- Duet Biosystems, Nashville, Tennessee, USA
- Antimicrobial Research Consortium (ARC) Labs, Boulder, Colorado, USA
| | - Bojun Zhou
- Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Meredith D. Betterton
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Physics, University of Colorado, Boulder, Colorado, USA
- Center for Computational Biology, Flatiron Institute, New York, New York, USA
| | | | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Corrella S. Detweiler
- Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
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10
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Bohorquez LC, de Sousa J, Garcia-Garcia T, Dugar G, Wang B, Jonker MJ, Noirot-Gros MF, Lalk M, Hamoen LW. Metabolic and chromosomal changes in a Bacillus subtilis whiA mutant. Microbiol Spectr 2023; 11:e0179523. [PMID: 37916812 PMCID: PMC10714963 DOI: 10.1128/spectrum.01795-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 10/10/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE WhiA is a conserved DNA-binding protein that influences cell division in many Gram-positive bacteria and, in B. subtilis, also chromosome segregation. How WhiA works in Bacillus subtilis is unknown. Here, we tested three hypothetical mechanisms using metabolomics, fatty acid analysis, and chromosome confirmation capture experiments. This revealed that WhiA does not influence cell division and chromosome segregation by modulating either central carbon metabolism or fatty acid composition. However, the inactivation of WhiA reduces short-range chromosome interactions. These findings provide new avenues to study the molecular mechanism of WhiA in the future.
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Affiliation(s)
- Laura C. Bohorquez
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Joana de Sousa
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Transito Garcia-Garcia
- Laboratoire de Genetique Microbienne, Domaine de Vilvert, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Gaurav Dugar
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Biwen Wang
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Martijs J. Jonker
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Marie-Françoise Noirot-Gros
- Laboratoire de Genetique Microbienne, Domaine de Vilvert, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Michael Lalk
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Leendert W. Hamoen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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11
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Valladares A, Picossi S, Corrales-Guerrero L, Herrero A. The role of SepF in cell division and diazotrophic growth in the multicellular cyanobacterium Anabaena sp. strain PCC 7120. Microbiol Res 2023; 277:127489. [PMID: 37716126 DOI: 10.1016/j.micres.2023.127489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/23/2023] [Accepted: 09/09/2023] [Indexed: 09/18/2023]
Abstract
The cyanobacterium Anabaena forms filaments of cells that grow by intercalary cell division producing adjoined daughter cells connected by septal junction protein complexes that provide filament cohesion and intercellular communication, representing a genuine case of bacterial multicellularity. In spite of their diderm character, cyanobacterial genomes encode homologs of SepF, a protein normally found in Gram-positive bacteria. In Anabaena, SepF is an essential protein that localized to the cell division ring and the intercellular septa. Overexpression of sepF had detrimental effects on growth, provoking conspicuous alterations in cell morphology that resemble the phenotype of mutants impaired in cell division, and altered the localization of the division-ring. SepF interacted with FtsZ and with the essential FtsZ tether ZipN. Whereas SepF from unicellular bacteria generally induces the bundling of FtsZ filaments, Anabaena SepF inhibited FtsZ bundling, reducing the thickness of the toroidal aggregates formed by FtsZ alone and eventually preventing FtsZ polymerization. Thus, in Anabaena SepF appears to have an essential role in cell division by limiting the polymerization of FtsZ to allow the correct formation and localization of the Z-ring. Expression of sepF is downregulated during heterocyst differentiation, likely contributing to the inhibition of Z-ring formation in heterocysts. Finally, the localization of SepF in intercellular septa and its interaction with the septal-junction related proteins SepJ and SepI suggest a role of SepF in the formation or stability of the septal complexes that mediate cell-cell adhesion and communication, processes that are key for the multicellular behavior of Anabaena.
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Affiliation(s)
- A Valladares
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - S Picossi
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - L Corrales-Guerrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - A Herrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain.
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12
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Harpring M, Cox JV. Plasticity in the cell division processes of obligate intracellular bacteria. Front Cell Infect Microbiol 2023; 13:1205488. [PMID: 37876871 PMCID: PMC10591338 DOI: 10.3389/fcimb.2023.1205488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 09/07/2023] [Indexed: 10/26/2023] Open
Abstract
Most bacteria divide through a highly conserved process called binary fission, in which there is symmetric growth of daughter cells and the synthesis of peptidoglycan at the mid-cell to enable cytokinesis. During this process, the parental cell replicates its chromosomal DNA and segregates replicated chromosomes into the daughter cells. The mechanisms that regulate binary fission have been extensively studied in several model organisms, including Eschericia coli, Bacillus subtilis, and Caulobacter crescentus. These analyses have revealed that a multi-protein complex called the divisome forms at the mid-cell to enable peptidoglycan synthesis and septation during division. In addition, rod-shaped bacteria form a multi-protein complex called the elongasome that drives sidewall peptidoglycan synthesis necessary for the maintenance of rod shape and the lengthening of the cell prior to division. In adapting to their intracellular niche, the obligate intracellular bacteria discussed here have eliminated one to several of the divisome gene products essential for binary fission in E. coli. In addition, genes that encode components of the elongasome, which were mostly lost as rod-shaped bacteria evolved into coccoid organisms, have been retained during the reductive evolutionary process that some coccoid obligate intracellular bacteria have undergone. Although the precise molecular mechanisms that regulate the division of obligate intracellular bacteria remain undefined, the studies summarized here indicate that obligate intracellular bacteria exhibit remarkable plasticity in their cell division processes.
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Affiliation(s)
| | - John V. Cox
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
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13
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Naha A, Haeusser DP, Margolin W. Anchors: A way for FtsZ filaments to stay membrane bound. Mol Microbiol 2023; 120:525-538. [PMID: 37503768 PMCID: PMC10593102 DOI: 10.1111/mmi.15067] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 07/29/2023]
Abstract
Most bacteria use the tubulin homolog FtsZ to organize their cell division. FtsZ polymers initially assemble into mobile complexes that circle around a ring-like structure at the cell midpoint, followed by the recruitment of other proteins that will constrict the cytoplasmic membrane and synthesize septal peptidoglycan to divide the cell. Despite the need for FtsZ polymers to associate with the membrane, FtsZ lacks intrinsic membrane binding ability. Consequently, FtsZ polymers have evolved to interact with the membrane through adaptor proteins that both bind FtsZ and the membrane. Here, we discuss recent progress in understanding the functions of these FtsZ membrane tethers. Some, such as FtsA and SepF, are widely conserved and assemble into varied oligomeric structures bound to the membrane through an amphipathic helix. Other less-conserved proteins, such as EzrA and ZipA, have transmembrane domains, make extended structures, and seem to bind to FtsZ through two separate interactions. This review emphasizes that most FtsZs use multiple membrane tethers with overlapping functions, which not only attach FtsZ polymers to the membrane but also organize them in specific higher-order structures that can optimize cell division activity. We discuss gaps in our knowledge of these concepts and how future studies can address them.
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Affiliation(s)
- Arindam Naha
- Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, TX 77030, USA
| | - Daniel P. Haeusser
- Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, TX 77030, USA
- Department of Biology, Canisius College, Buffalo, NY 14208, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, TX 77030, USA
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14
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Allgood SC, Su CC, Crooks AL, Meyer CT, Zhou B, Betterton MD, Barbachyn MR, Yu EW, Detweiler CS. Bacterial Efflux Pump Modulators Prevent Bacterial Growth in Macrophages and Under Broth Conditions that Mimic the Host Environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.20.558466. [PMID: 37786697 PMCID: PMC10541609 DOI: 10.1101/2023.09.20.558466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
New approaches for combatting microbial infections are needed. One strategy for disrupting pathogenesis involves developing compounds that interfere with bacterial virulence. A critical molecular determinant of virulence for Gram-negative bacteria are efflux pumps of the resistance-nodulation-division (RND) family, which includes AcrAB-TolC. We previously identified small molecules that bind AcrB, inhibit AcrAB-TolC, and do not appear to damage membranes. These efflux pump modulators (EPMs) were discovered in an in-cell screening platform called SAFIRE (Screen for Anti-infectives using Fluorescence microscopy of IntracellulaR Enterobacteriaceae). SAFIRE identifies compounds that disrupt the growth of a Gram-negative human pathogen, Salmonella enterica serotype Typhimurium (S. Typhimurium) in macrophages. We used medicinal chemistry to iteratively design ~200 EPM35 analogs and test them for activity in SAFIRE, generating compounds with nanomolar potency. Analogs were demonstrated to bind AcrB in a substrate binding pocket by cryo-electron microscopy (cryo-EM). Despite having amphipathic structures, the EPM analogs do not disrupt membrane voltage, as monitored by FtsZ localization to the cell septum. The EPM analogs had little effect on bacterial growth in standard Mueller Hinton Broth. However, under broth conditions that mimic the micro-environment of the macrophage phagosome, acrAB is required for growth, the EPM analogs are bacteriostatic, and increase the potency of antibiotics. These data suggest that under macrophage-like conditions the EPM analogs prevent the export of a toxic bacterial metabolite(s) through AcrAB-TolC. Thus, compounds that bind AcrB could disrupt infection by specifically interfering with the export of bacterial toxic metabolites, host defense factors, and/or antibiotics.
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Affiliation(s)
- Samual C Allgood
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Amy L Crooks
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Christian T Meyer
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
- Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA
- Duet Biosystems, Nashville, TN, USA
- Antimicrobial Research Consortium (ARC) Labs, Boulder, CO, USA
| | - Bojun Zhou
- Department of Physics, University of Colorado, Boulder, CO, USA
| | - Meredith D Betterton
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
- Center for Computational Biology, Flatiron Institute, New York, NY, USA
| | | | - Edward W Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Corrella S Detweiler
- Molecular, Cellular Developmental Biology, University of Colorado Boulder, Boulder, CO, USA
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15
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Fujita J, Amesaka H, Yoshizawa T, Hibino K, Kamimura N, Kuroda N, Konishi T, Kato Y, Hara M, Inoue T, Namba K, Tanaka SI, Matsumura H. Structures of a FtsZ single protofilament and a double-helical tube in complex with a monobody. Nat Commun 2023; 14:4073. [PMID: 37429870 DOI: 10.1038/s41467-023-39807-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 06/27/2023] [Indexed: 07/12/2023] Open
Abstract
FtsZ polymerizes into protofilaments to form the Z-ring that acts as a scaffold for accessory proteins during cell division. Structures of FtsZ have been previously solved, but detailed mechanistic insights are lacking. Here, we determine the cryoEM structure of a single protofilament of FtsZ from Klebsiella pneumoniae (KpFtsZ) in a polymerization-preferred conformation. We also develop a monobody (Mb) that binds to KpFtsZ and FtsZ from Escherichia coli without affecting their GTPase activity. Crystal structures of the FtsZ-Mb complexes reveal the Mb binding mode, while addition of Mb in vivo inhibits cell division. A cryoEM structure of a double-helical tube of KpFtsZ-Mb at 2.7 Å resolution shows two parallel protofilaments. Our present study highlights the physiological roles of the conformational changes of FtsZ in treadmilling that regulate cell division.
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Affiliation(s)
- Junso Fujita
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hiroshi Amesaka
- Graduate School of Life and Environmental Science, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Takuya Yoshizawa
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kota Hibino
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Natsuki Kamimura
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Natsuko Kuroda
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Takamoto Konishi
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Yuki Kato
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Mizuho Hara
- Graduate School of Life and Environmental Science, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Tsuyoshi Inoue
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Open and Transdisciplinary Research Initiatives, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
- dotAqua Inc., 2-1 Yamadaoka, Suita, Osaka, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan
- RIKEN Center for Biosystems Dynamics Research and SPring-8 Center, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shun-Ichi Tanaka
- Graduate School of Life and Environmental Science, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto, 606-8522, Japan.
| | - Hiroyoshi Matsumura
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
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16
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Morrison JJ, Ferreira CN, Siler EM, Nelson K, Trebino CE, Piraino B, Camberg JL. Nucleotide-dependent activities of FtsA regulate the early establishment of a functional divisome during the Escherichia coli cell cycle. Front Microbiol 2023; 14:1171376. [PMID: 37250038 PMCID: PMC10213515 DOI: 10.3389/fmicb.2023.1171376] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
During cell division in Escherichia coli, the highly conserved tubulin homolog FtsZ polymerizes and assembles into a ring-like structure, called the Z-ring, at the site of septation. For recruitment to the membrane surface, FtsZ polymers directly interact with membrane-associated proteins, predominantly FtsA in E. coli. FtsA shares structural homology with actin and, like actin, hydrolyzes ATP. Yeast actin detects nucleotide occupancy through a sensor region adjacent to the nucleotide binding site and adopts distinct conformations in monomeric and filamentous actin. Bacterial actin homologs also display considerable conformational flexibility across different nucleotide-bound states and polymerize. Here, we show that several amino acid residues proximal to the nucleotide binding site in FtsA are critical for function in vitro and in vivo. Each of these residues are important for ATP hydrolysis, phospholipid (PL) binding, ATP-dependent vesicle remodeling, and recruitment to the divisome in vivo, to varying degrees. Notably, we observed that Ser 84 and Glu 14 are essential for ATP-dependent vesicle remodeling and magnesium-dependent membrane release of FtsA from vesicles in vitro, and these defects likely underlie the loss of function by FtsA(E14R) and FtsA(S84L) in vivo. Finally, we demonstrate that FtsA(A188V), which is associated with temperature-sensitive growth in vivo, is defective for rapid ATP hydrolysis and ATP-dependent remodeling of PL vesicles in vitro. Together, our results show that loss of nucleotide-dependent activities by FtsA, such as ATP hydrolysis, membrane binding and release, and, most importantly, ATP-dependent PL remodeling, lead to failed Z-ring assembly and division defects in cells.
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17
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Chen YW, Kong WP, Wong KY. The structural integrity of the membrane-embedded bacterial division complex FtsQBL studied with molecular dynamics simulations. Comput Struct Biotechnol J 2023; 21:2602-2612. [PMID: 37114213 PMCID: PMC10126914 DOI: 10.1016/j.csbj.2023.03.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
The FtsQBL is an essential molecular complex sitting midway through bacterial divisome assembly. To visualize and understand its structure, and the consequences of its membrane anchorage, we produced a model of the E. coli complex using the deep-learning prediction utility, AlphaFold 2. The heterotrimeric model was inserted into a 3-lipid model membrane and subjected to a 500-ns atomistic molecular dynamics simulation. The model is superb in quality and captures most experimentally derived structural features, at both the secondary structure and the side-chain levels. The model consists of a uniquely interlocking module contributed by the C-terminal regions of all three proteins. The functionally important constriction control domain residues of FtsB and FtsL are located at a fixed vertical position of ∼43-49 Å from the membrane surface. While the periplasmic domains of all three proteins are well-defined and rigid, the single transmembrane helices of each are flexible and their collective twisting and bending contribute to most structural variations, according to principal component analysis. Considering FtsQ only, the protein is more flexible in its free state relative to its complexed state-with the biggest structural changes located at the elbow between the transmembrane helix and the α-domain. The disordered N-terminal domains of FtsQ and FtsL associate with the cytoplasmic surface of the inner membrane instead of freely venturing into the solvent. Contact network analysis highlighted the formation of the interlocking trimeric module in FtsQBL as playing a central role in mediating the overall structure of the complex.
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Affiliation(s)
- Yu Wai Chen
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Wai-Po Kong
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Kwok-Yin Wong
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
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18
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Smrt ST, Escobar CA, Dey S, Cross TA, Zhou HX. An Arg/Ala-rich helix in the N-terminal region of M. tuberculosis FtsQ is a potential membrane anchor of the Z-ring. Commun Biol 2023; 6:311. [PMID: 36959324 PMCID: PMC10036325 DOI: 10.1038/s42003-023-04686-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/09/2023] [Indexed: 03/25/2023] Open
Abstract
Mtb infects a quarter of the worldwide population. Most drugs for treating tuberculosis target cell growth and division. With rising drug resistance, it becomes ever more urgent to better understand Mtb cell division. This process begins with the formation of the Z-ring via polymerization of FtsZ and anchoring of the Z-ring to the inner membrane. Here we show that the transmembrane protein FtsQ is a potential membrane anchor of the Mtb Z-ring. In the otherwise disordered cytoplasmic region of FtsQ, a 29-residue, Arg/Ala-rich α-helix is formed that interacts with upstream acidic residues in solution and with acidic lipids at the membrane surface. This helix also binds to the GTPase domain of FtsZ, with implications for drug binding and Z-ring formation.
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Affiliation(s)
- Sean T Smrt
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA
| | - Cristian A Escobar
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA
| | - Souvik Dey
- Department of Chemistry, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Timothy A Cross
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA.
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA.
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA.
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois Chicago, Chicago, IL, 60607, USA.
- Department of Physics, University of Illinois Chicago, Chicago, IL, 60607, USA.
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19
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Construction and Characterization of Functional FtsA Sandwich Fusions for Studies of FtsA Localization and Dynamics during Escherichia coli Cell Division. J Bacteriol 2023; 205:e0037322. [PMID: 36622232 PMCID: PMC9879108 DOI: 10.1128/jb.00373-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
FtsA, a homolog of actin, is essential for cell division of Escherichia coli and is widely conserved among many bacteria. FtsA helps to tether polymers of the bacterial tubulin homolog FtsZ to the cytoplasmic membrane as part of the cytokinetic Z ring. GFP fusions to FtsA have illuminated FtsA's localization in live E. coli, but these fusions have not been fully functional and required the presence of the native FtsA. Here, we characterize "sandwich" fusions of E. coli FtsA to either mCherry or msfGFP that are functional for cell division and exhibit fluorescent rings at midcell that persist throughout constriction until cell separation. FtsA within the Z ring moved circumferentially like FtsZ, and FtsA outside the rings formed highly dynamic patches at the membrane. Notably, both FtsA-mCherrysw and FtsA-msfGFPsw acted as mild hypermorphs, as they were not toxic when overproduced, bypassed the essential cell division protein ZipA, and suppressed several thermosensitive fts alleles, although not as effectively as the prototypical hypermorph FtsA*. Overall, our results indicate that fluorescent FtsA sandwich fusions can be used as the sole FtsA in E. coli and thus should shed new light on FtsA dynamics during the cell division cycle in this model system. IMPORTANCE FtsA is a key conserved cell division protein, and E. coli is the most well studied model system for bacterial cell division. One obstacle to full understanding of this process is the lack of a fully functional fluorescent reporter for FtsA in vivo. Here, we describe a fluorescent fusion to E. coli FtsA that promotes efficient cell division in the absence of the native FtsA and can be used to monitor FtsA dynamics during cell division.
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20
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Du RL, Chow HY, Chen YW, Chan PH, Daniel RA, Wong KY. Gossypol acetate: A natural polyphenol derivative with antimicrobial activities against the essential cell division protein FtsZ. Front Microbiol 2023; 13:1080308. [PMID: 36713210 PMCID: PMC9878342 DOI: 10.3389/fmicb.2022.1080308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/28/2022] [Indexed: 01/14/2023] Open
Abstract
Antimicrobial resistance has attracted worldwide attention and remains an urgent issue to resolve. Discovery of novel compounds is regarded as one way to circumvent the development of resistance and increase the available treatment options. Gossypol is a natural polyphenolic aldehyde, and it has attracted increasing attention as a possible antibacterial drug. In this paper, we studied the antimicrobial properties (minimum inhibitory concentrations) of gossypol acetate against both Gram-positive and Gram-negative bacteria strains and dig up targets of gossypol acetate using in vitro assays, including studying its effects on functions (GTPase activity and polymerization) of Filamenting temperature sensitive mutant Z (FtsZ) and its interactions with FtsZ using isothermal titration calorimetry (ITC), and in vivo assays, including visualization of cell morphologies and proteins localizations using a microscope. Lastly, Bacterial membrane permeability changes were studied, and the cytotoxicity of gossypol acetate was determined. We also estimated the interactions of gossypol acetate with the promising target. We found that gossypol acetate can inhibit the growth of Gram-positive bacteria such as the model organism Bacillus subtilis and the pathogen Staphylococcus aureus [both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA)]. In addition, gossypol acetate can also inhibit the growth of Gram-negative bacteria when the outer membrane is permeabilized by Polymyxin B nonapeptide (PMBN). Using a cell biological approach, we show that gossypol acetate affects cell division in bacteria by interfering with the assembly of the cell division FtsZ ring. Biochemical analysis shows that the GTPase activity of FtsZ was inhibited and polymerization of FtsZ was enhanced in vitro, consistent with the block to cell division in the bacteria tested. The binding mode of gossypol acetate in FtsZ was modeled using molecular docking and provides an understanding of the compound mode of action. The results point to gossypol (S2303) as a promising antimicrobial compound that inhibits cell division by affecting FtsZ polymerization and has potential to be developed into an effective antimicrobial drug by chemical modification to minimize its cytotoxic effects in eukaryotic cells that were identified in this work.
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Affiliation(s)
- Ruo-Lan Du
- Department of Applied Biology and Chemical Technology and the State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Ho-Yin Chow
- Department of Applied Biology and Chemical Technology and the State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Yu Wei Chen
- Department of Applied Biology and Chemical Technology and the State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Pak-Ho Chan
- Department of Applied Biology and Chemical Technology and the State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Richard A. Daniel
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom,Richard A. Daniel,
| | - Kwok-Yin Wong
- Department of Applied Biology and Chemical Technology and the State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China,*Correspondence: Kwok-Yin Wong,
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21
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Dey S, Zhou HX. Membrane Tethering of SepF, a Membrane Anchor for the Mycobacterium tuberculosis Z-ring. J Mol Biol 2022; 434:167817. [PMID: 36087777 PMCID: PMC9992448 DOI: 10.1016/j.jmb.2022.167817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/30/2022] [Accepted: 08/31/2022] [Indexed: 11/23/2022]
Abstract
Bacterial cell division begins with the formation of the Z-ring via polymerization of FtsZ and the localization of Z-ring beneath the inner membrane through membrane anchors. In Mycobacterium tuberculosis (Mtb), SepF is one such membrane anchor, but our understanding of the underlying mechanism is very limited. Here we used molecular dynamics simulations to characterize how SepF itself, a water-soluble protein, tethers to acidic membranes that mimic the Mtb inner membrane. In addition to an amphipathic helix (residues 1-12) at the N-terminus, membrane binding also occurs through two stretches of positively charged residues (Arg27-Arg37 and Arg95-Arg107) in the long linker preceding the FtsZ-binding core domain (residues 128-218). The additional interactions via the disordered linker stabilize the membrane tethering of SepF, and keep the core domain of SepF and hence the attached Z-ring close to the membrane. The resulting membrane proximity of the Z-ring in turn enables its interactions with and thus recruitment of two membrane proteins, FtsW and CrgA, at the late stage of cell division.
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Affiliation(s)
- Souvik Dey
- Department of Chemistry, University of Illinois at Chicago, IL 60607, USA
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois at Chicago, IL 60607, USA; Department of Physics, University of Illinois at Chicago, IL 60607, USA.
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22
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Herianto S, Chien PJ, Ho JAA, Tu HL. Liposome-based artificial cells: From gene expression to reconstitution of cellular functions and phenotypes. BIOMATERIALS ADVANCES 2022; 142:213156. [PMID: 36302330 DOI: 10.1016/j.bioadv.2022.213156] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
Bottom-up approaches in creating artificial cells that can mimic natural cells have significant implications for both basic research and translational application. Among various artificial cell models, liposome is one of the most sophisticated systems. By encapsulating proteins and associated biomolecules, they can functionally reconstitute foundational features of biological cells, such as the ability to divide, communicate, and undergo shape deformation. Yet constructing liposome artificial cells from the genetic level, which is central to generate self-sustained systems remains highly challenging. Indeed, many studies have successfully established the expression of gene-coded proteins inside liposomes. Further, recent endeavors to build a direct integration of gene-expressed proteins for reconstituting molecular functions and phenotypes in liposomes have also significantly increased. Thus, this review presents the development of liposome-based artificial cells to demonstrate the process of gene-expressed proteins and their reconstitution to perform desired molecular and cell-like functions. The molecular and cellular phenotypes discussed here include the self-production of membrane phospholipids, division, shape deformation, self-DNA/RNA replication, fusion, and intercellular communication. Together, this review gives a comprehensive overview of gene-expressing liposomes that can stimulate further research of this technology and achieve artificial cells with superior properties in the future.
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Affiliation(s)
- Samuel Herianto
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan; Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan; Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Po-Jen Chien
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Ja-An Annie Ho
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan; BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan; Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan.
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23
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Babl L, Merino-Salomón A, Kanwa N, Schwille P. Membrane mediated phase separation of the bacterial nucleoid occlusion protein Noc. Sci Rep 2022; 12:17949. [PMID: 36289351 PMCID: PMC9606368 DOI: 10.1038/s41598-022-22680-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/18/2022] [Indexed: 01/24/2023] Open
Abstract
Liquid-liquid phase separation is a fundamental biophysical process to organize eukaryotic and prokaryotic cytosols. While many biomolecular condensates are formed in the vicinity of, or even on lipid membranes, little is known about the interaction of protein condensates and lipid bilayers. In this study, we characterize the recently unknown phase behavior of the bacterial nucleoid occlusion protein Noc. We find that, similarly to other ParB-like proteins, CTP binding tightly regulates Noc's propensity to phase separate. As CTP-binding and hydrolysis also allows Noc to bind and spread on membranes, we furthermore establish Noc condensates as model system to investigate how lipid membranes can influence protein condensation and vice versa. Last, we show that Noc condensates can recruit FtsZ to the membrane, while this does not happen in the non-phase separated state. These findings suggest a new model of Noc mediated nucleoid occlusion, with membrane-mediated liquid-liquid phase separation as underlying principle of complex formation and regulation thereof.
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Affiliation(s)
- Leon Babl
- grid.418615.f0000 0004 0491 845XMax Planck Institute for Biochemistry, Am Klopferspitz 18, 82152 Planegg, Germany
| | - Adrián Merino-Salomón
- grid.418615.f0000 0004 0491 845XMax Planck Institute for Biochemistry, Am Klopferspitz 18, 82152 Planegg, Germany
| | - Nishu Kanwa
- grid.418615.f0000 0004 0491 845XMax Planck Institute for Biochemistry, Am Klopferspitz 18, 82152 Planegg, Germany
| | - Petra Schwille
- grid.418615.f0000 0004 0491 845XMax Planck Institute for Biochemistry, Am Klopferspitz 18, 82152 Planegg, Germany
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24
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Nierhaus T, McLaughlin SH, Bürmann F, Kureisaite-Ciziene D, Maslen SL, Skehel JM, Yu CWH, Freund SMV, Funke LFH, Chin JW, Löwe J. Bacterial divisome protein FtsA forms curved antiparallel double filaments when binding to FtsN. Nat Microbiol 2022; 7:1686-1701. [PMID: 36123441 PMCID: PMC7613929 DOI: 10.1038/s41564-022-01206-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 07/19/2022] [Indexed: 11/08/2022]
Abstract
During bacterial cell division, filaments of tubulin-like FtsZ form the Z-ring, which is the cytoplasmic scaffold for divisome assembly. In Escherichia coli, the actin homologue FtsA anchors the Z-ring to the membrane and recruits divisome components, including bitopic FtsN. FtsN regulates the periplasmic peptidoglycan synthase FtsWI. To characterize how FtsA regulates FtsN, we applied electron microscopy to show that E. coli FtsA forms antiparallel double filaments on lipid monolayers when bound to the cytoplasmic tail of FtsN. Using X-ray crystallography, we demonstrate that Vibrio maritimus FtsA crystallizes as an equivalent double filament. We identified an FtsA-FtsN interaction site in the IA-IC interdomain cleft of FtsA using X-ray crystallography and confirmed that FtsA forms double filaments in vivo by site-specific cysteine cross-linking. FtsA-FtsN double filaments reconstituted in or on liposomes prefer negative Gaussian curvature, like those of MreB, the actin-like protein of the elongasome. We propose that curved antiparallel FtsA double filaments together with treadmilling FtsZ filaments organize septal peptidoglycan synthesis in the division plane.
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Affiliation(s)
- Tim Nierhaus
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | | | | | - Sarah L Maslen
- MRC Laboratory of Molecular Biology, Cambridge, UK
- The Francis Crick Institute, London, UK
| | - J Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge, UK
- The Francis Crick Institute, London, UK
| | - Conny W H Yu
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | | | - Jason W Chin
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Cambridge, UK.
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Lyu Z, Yahashiri A, Yang X, McCausland JW, Kaus GM, McQuillen R, Weiss DS, Xiao J. FtsN maintains active septal cell wall synthesis by forming a processive complex with the septum-specific peptidoglycan synthases in E. coli. Nat Commun 2022; 13:5751. [PMID: 36180460 PMCID: PMC9525312 DOI: 10.1038/s41467-022-33404-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 09/16/2022] [Indexed: 01/06/2023] Open
Abstract
FtsN plays an essential role in promoting the inward synthesis of septal peptidoglycan (sPG) by the FtsWI complex during bacterial cell division. How it achieves this role is unclear. Here we use single-molecule tracking to investigate FtsN's dynamics during sPG synthesis in E. coli. We show that septal FtsN molecules move processively at ~9 nm s-1, the same as FtsWI molecules engaged in sPG synthesis (termed sPG-track), but much slower than the ~30 nm s-1 speed of inactive FtsWI molecules coupled to FtsZ's treadmilling dynamics (termed FtsZ-track). Importantly, processive movement of FtsN is exclusively coupled to sPG synthesis and is required to maintain active sPG synthesis by FtsWI. Our findings indicate that FtsN is part of the FtsWI sPG synthesis complex, and that while FtsN is often described as a "trigger" for the initiation for cell wall constriction, it must remain part of the processive FtsWI complex to maintain sPG synthesis activity.
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Affiliation(s)
- Zhixin Lyu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Atsushi Yahashiri
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Xinxing Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Joshua W McCausland
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Gabriela M Kaus
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Ryan McQuillen
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - David S Weiss
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
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26
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Männik J, Pichoff S, Lutkenhaus J, Männik J. Cell Cycle-Dependent Recruitment of FtsN to the Divisome in Escherichia coli. mBio 2022; 13:e0201722. [PMID: 35968943 PMCID: PMC9426451 DOI: 10.1128/mbio.02017-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 12/13/2022] Open
Abstract
Cell division in Escherichia coli starts with the formation of an FtsZ protofilament network at midcell, the Z ring. However, only after a considerable lag period does the cell start to form a midcell constriction. The onset of constriction depends upon the arrival of so-called late divisome proteins, among which, FtsN is the last essential one. The timing and dependency of FtsN arrival to the divisome, along with genetic evidence, suggests it triggers cell division. In this study, we used high-throughput fluorescence microscopy to determine the arrival of FtsN and the early divisome protein ZapA to midcell at a single-cell level during the cell cycle. Our data show while the recruitment of ZapA/FtsZ is gradual in the cell cycle, recruitment of FtsN is rapid and begins at about the onset of constriction. At this time, the fraction of ZapA/FtsZ in the Z ring approaches its peak value. We also find a second increase in FtsN recruitment to the divisome, which begins once the amount of ZapA/FtsZ at midcell starts decreasing. Increasing hypermorphic FtsA* (FtsA R286W), but not FtsA, accelerates FtsN recruitment but not constriction. This finding is consistent with FtsA* recruiting FtsN with some other divisome component being rate-limiting for constriction under these conditions. Finally, our data support the recently proposed idea that ZapA/FtsZ and FtsN are part of physically separate complexes in midcell throughout the whole septation process. IMPORTANCE Cell division in most bacteria starts with the formation of an FtsZ protofilament network at midcell, the Z ring. However, cells only start to constrict after a considerable lag. A factor thought to trigger the onset of constriction in Escherichia coli is FtsN, which is the last essential protein to be recruited to the Z ring. Using a high-throughput quantitative fluorescence microscopy, we determine the cell cycle-dependent recruitment of FtsN to the Z ring. Our data show rapid accumulation of FtsN to the Z ring about a quarter of the cell cycle after the formation of the Z ring. This initial wave is followed by another increase in FtsN recruitment once the FtsZ protofilament network starts to disassemble. The presence of FtsA* accelerates FtsN recruitment to the Z ring but does not lead to earlier constrictions. Our data furthermore suggest FtsZ and FtsN are part of physically separate complexes throughout the division process.
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Affiliation(s)
- Jaana Männik
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, USA
| | - Sebastien Pichoff
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Joe Lutkenhaus
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jaan Männik
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, USA
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Godino E, Doerr A, Danelon C. Min waves without MinC can pattern FtsA-anchored FtsZ filaments on model membranes. Commun Biol 2022; 5:675. [PMID: 35798943 PMCID: PMC9262947 DOI: 10.1038/s42003-022-03640-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/28/2022] [Indexed: 11/14/2022] Open
Abstract
Although the essential proteins that drive bacterial cytokinesis have been identified, the precise mechanisms by which they dynamically interact to enable symmetrical division are largely unknown. In Escherichia coli, cell division begins with the formation of a proto-ring composed of FtsZ and its membrane-tethering proteins FtsA and ZipA. In the broadly proposed molecular scenario for ring positioning, Min waves composed of MinD and MinE distribute the FtsZ-polymerization inhibitor MinC away from mid-cell, where the Z-ring can form. Therefore, MinC is believed to be an essential element connecting the Min and FtsZ subsystems. Here, by combining cell-free protein synthesis with planar lipid membranes and microdroplets, we demonstrate that MinDE drive the formation of dynamic, antiphase patterns of FtsA-anchored FtsZ filaments even in the absence of MinC. These results suggest that Z-ring positioning may be achieved with a more minimal set of proteins than previously envisaged, providing a fresh perspective about synthetic cell division. Cell-free protein synthesis of bacterial cytokinesis factors reveals that MinDE surface waves regulate FtsA-anchored FtsZ filaments in time and space independently of MinC.
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Affiliation(s)
- Elisa Godino
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629HZ, The Netherlands
| | - Anne Doerr
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629HZ, The Netherlands
| | - Christophe Danelon
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629HZ, The Netherlands.
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28
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Wang S, Zhao X, Sun K, Bateer H, Wang W. The Genome Sequence of Brucella abortus vaccine strain A19 provides insights on its virulence attenuation compared to Brucella abortus strain 9-941. Gene 2022; 830:146521. [PMID: 35447245 DOI: 10.1016/j.gene.2022.146521] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/20/2021] [Accepted: 04/15/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Brucellosis is a widespread disease that affects animals and humans. The live attenuated Brucella abortus A19 strain is used for vaccination against brucellosis in China. In addition, the main mechanisms supporting the residual toxicity of A19 have not been elucidated. Here, we performed a comprehensive comparative analysis of the genome-wide sequence of A19 against the whole genome sequences of the published virulent reference strain 9-941. The primary objective of this study was to identify candidate virulence genes by systematically comparing the genomic sequences between the two genomes. RESULTS This analysis revealed two deletion regions in the A19 genome, in which all included large fragments of 63 bp, and one of their gene function is related to ABC transporter permease protein. In addition, we have identified minor mutations in important virulence-related genes that can be used to determine the underlying mechanisms of virulence attenuation. The function of its virulence gene covers LysR family transcriptional regulator, outer membrane, MFS transporter and oxidoreductase etc. At the same time, a PCR differential diagnosis method was constructed, which can distinguish A19, S19 and most other commonly used Brucella viruent strains and vaccine strains. CONCLUSION The data may help to provide resources for further detailed analysis of mechanisms for other Brucella vaccines. It laid the foundation for further distinguishing between vaccine immunity and virulent strains infection.
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Affiliation(s)
- Shuyi Wang
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture/College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China; Inner Mongolia Autonomous Region Comprehensive Center for Disease Control and Prevention, Hohhot, Inner Mongolia 010031, China
| | - Xueliang Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling 712100, China
| | - Ke Sun
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture/College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China
| | - Huhe Bateer
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture/College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China
| | - Wenlong Wang
- Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture/College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China.
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Shi M, Li M, Yang A, Miao X, Yang L, Pandhal J, Zou H. Class I Polyhydroxyalkanoate (PHA) Synthase Increased Polylactic Acid Production in Engineered Escherichia Coli. Front Bioeng Biotechnol 2022; 10:919969. [PMID: 35814019 PMCID: PMC9261260 DOI: 10.3389/fbioe.2022.919969] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/09/2022] [Indexed: 11/24/2022] Open
Abstract
Polylactic acid (PLA), a homopolymer of lactic acid (LA), is a bio-derived, biocompatible, and biodegradable polyester. The evolved class II PHA synthase (PhaC1Ps6-19) was commonly utilized in the de novo biosynthesis of PLA from biomass. This study tested alternative class I PHA synthase (PhaCCs) from Chromobacterium sp. USM2 in engineered Escherichia coli for the de novo biosynthesis of PLA from glucose. The results indicated that PhaCCs had better performance in PLA production than that of class II synthase PhaC1Ps6-19. In addition, the sulA gene was engineered in PLA-producing strains for morphological engineering. The morphologically engineered strains present increased PLA production. This study also tested fused propionyl-CoA transferase and lactate dehydrogenase A (fused PctCp/LdhA) in engineered E. coli and found that fused PctCp/LdhA did not apparently improve the PLA production. After systematic engineering, the highest PLA production was achieved by E. coli MS6 (with PhaCCs and sulA), which could produce up to 955.0 mg/L of PLA in fed-batch fermentation with the cell dry weights of 2.23%, and the average molecular weight of produced PLA could reach 21,000 Da.
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Affiliation(s)
- Mengxun Shi
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
- Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield, United Kingdom
| | - Mengdi Li
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Anran Yang
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Xue Miao
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Liu Yang
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Jagroop Pandhal
- Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield, United Kingdom
| | - Huibin Zou
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, China
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
- *Correspondence: Huibin Zou, ,
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30
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RefZ and Noc Act Synthetically to Prevent Aberrant Divisions during Bacillus subtilis Sporulation. J Bacteriol 2022; 204:e0002322. [PMID: 35506695 DOI: 10.1128/jb.00023-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During sporulation, Bacillus subtilis undergoes an atypical cell division that requires overriding mechanisms that protect chromosomes from damage and ensure inheritance by daughter cells. Instead of assembling between segregated chromosomes at midcell, the FtsZ-ring coalesces polarly, directing division over one chromosome. The DNA-binding protein RefZ facilitates the timely assembly of polar Z-rings and partially defines the region of chromosome initially captured in the forespore. RefZ binds to motifs (RBMs) located proximal to the origin of replication (oriC). Although refZ and the RBMs are conserved across the Bacillus genus, a refZ deletion mutant sporulates with wild-type efficiency, so the functional significance of RefZ during sporulation remains unclear. To further investigate RefZ function, we performed a candidate-based screen for synthetic sporulation defects by combining ΔrefZ with deletions of genes previously implicated in FtsZ regulation and/or chromosome capture. Combining ΔrefZ with deletions of ezrA, sepF, parA, or minD did not detectably affect sporulation. In contrast, a ΔrefZ Δnoc mutant exhibited a sporulation defect, revealing a genetic interaction between RefZ and Noc. Using reporters of sporulation progression, we determined the ΔrefZ Δnoc mutant exhibited sporulation delays after Spo0A activation but prior to late sporulation, with a subset of cells failing to divide polarly or activate the first forespore-specific sigma factor, SigF. The ΔrefZ Δnoc mutant also exhibited extensive dysregulation of cell division, producing cells with extra, misplaced, or otherwise aberrant septa. Our results reveal a previously unknown epistatic relationship that suggests refZ and noc contribute synthetically to regulating cell division and supporting spore development. IMPORTANCE The DNA-binding protein RefZ and its binding sites (RBMs) are conserved in sequence and location on the chromosome across the Bacillus genus and contribute to the timing of polar FtsZ-ring assembly during sporulation. Only a small number of noncoding and nonregulatory DNA motifs are known to be conserved in chromosomal position in bacteria, suggesting there is strong selective pressure for their maintenance; however, a refZ deletion mutant sporulates efficiently, providing no clues as to their functional significance. Here, we find that in the absence of the nucleoid occlusion factor Noc, deletion of refZ results in a sporulation defect characterized by developmental delays and aberrant divisions.
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31
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Saaki TNV, Teng Z, Wenzel M, Ventroux M, Carballido-Lόpez R, Noirot-Gros MF, Hamoen LW. SepF supports the recruitment of the DNA translocase SftA to the Z-ring. Mol Microbiol 2022; 117:1263-1274. [PMID: 35411648 PMCID: PMC9320952 DOI: 10.1111/mmi.14906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/07/2022] [Accepted: 04/09/2022] [Indexed: 11/28/2022]
Abstract
In many bacteria, cell division begins before the sister chromosomes are fully segregated. Specific DNA translocases ensure that the chromosome is removed from the closing septum, such as the transmembrane protein FtsK in Escherichia coli. Bacillus subtilis contains two FtsK homologues, SpoIIIE and SftA. SftA is active during vegetative growth whereas SpoIIIE is primarily active during sporulation and pumps the chromosome into the spore compartment. FtsK and SpoIIIE contain several transmembrane helices, however SftA is assumed to be a cytoplasmic protein. It is unknown how SftA is recruited to the cell division site. Here we show that SftA is a peripheral membrane protein, containing an N-terminal amphipathic helix that reversibly anchors the protein to the cell membrane. Using a yeast two-hybrid screen we found that SftA interacts with the conserved cell division protein SepF. Based on extensive genetic analyses and previous data we propose that the septal localization of SftA depends on either SepF or the cell division protein FtsA. Since SftA seems to interfere with the activity of SepF, and since inactivation of SepF mitigates the sensitivity of a ∆sftA mutant for ciprofloxacin, we speculate that SftA might delay septum synthesis when chromosomal DNA is in the vicinity.
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Affiliation(s)
- Terrens N V Saaki
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Zihao Teng
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
| | - Michaela Wenzel
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands.,current address: Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Magali Ventroux
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay Jouy-en-Josas, France
| | - Rut Carballido-Lόpez
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay Jouy-en-Josas, France
| | | | - Leendert W Hamoen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, The Netherlands
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32
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Wang J, Bulgheresi S, den Blaauwen T. The Longitudinal Dividing Bacterium Candidatus Thiosymbion Oneisti Has a Natural Temperature-Sensitive FtsZ Protein with Low GTPase Activity. Int J Mol Sci 2022; 23:3016. [PMID: 35328438 PMCID: PMC8953583 DOI: 10.3390/ijms23063016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 02/01/2023] Open
Abstract
FtsZ, the bacterial tubulin-homolog, plays a central role in cell division and polymerizes into a ring-like structure at midcell to coordinate other cell division proteins. The rod-shaped gamma-proteobacterium Candidatus Thiosymbion oneisti has a medial discontinuous ellipsoidal "Z-ring." Ca. T. oneisti FtsZ shows temperature-sensitive characteristics when it is expressed in Escherichia coli, where it localizes at midcell. The overexpression of Ca. T. oneisti FtsZ interferes with cell division and results in filamentous cells. In addition, it forms ring- and barrel-like structures independently of E. coli FtsZ, which suggests that the difference in shape and size of the Ca. T. oneisti FtsZ ring is likely the result of its interaction with Z-ring organizing proteins. Similar to some temperature-sensitive alleles of E. coli FtsZ, Ca. T. oneisti FtsZ has a weak GTPase and does not polymerize in vitro. The temperature sensitivity of Ca. Thiosymbion oneisti FtsZ is likely an adaptation to the preferred temperature of less than 30 °C of its host, the nematode Laxus oneistus.
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Affiliation(s)
- Jinglan Wang
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
| | - Silvia Bulgheresi
- Environmental Cell Biology, Department of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria;
| | - Tanneke den Blaauwen
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
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33
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Morrison JJ, Conti J, Camberg JL. Assembly and architecture of Escherichia coli divisome proteins FtsA and FtsZ. J Biol Chem 2022; 298:101663. [PMID: 35104502 PMCID: PMC8897712 DOI: 10.1016/j.jbc.2022.101663] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 11/30/2022] Open
Abstract
During Escherichia coli cell division, an intracellular complex of cell division proteins known as the Z-ring assembles at midcell during early division and serves as the site of constriction. While the predominant protein in the Z-ring is the widely conserved tubulin homolog FtsZ, the actin homolog FtsA tethers the Z-ring scaffold to the cytoplasmic membrane by binding to FtsZ. While FtsZ is known to function as a dynamic, polymerized GTPase, the assembly state of its partner, FtsA, and the role of ATP are still unclear. We report that a substitution mutation in the FtsA ATP-binding site impairs ATP hydrolysis, phospholipid vesicle remodeling in vitro, and Z-ring assembly in vivo. We demonstrate by transmission electron microscopy and Förster Resonance Energy Transfer that a truncated FtsA variant, FtsA(ΔMTS) lacking a C-terminal membrane targeting sequence, self assembles into ATP-dependent filaments. These filaments coassemble with FtsZ polymers but are destabilized by unassembled FtsZ. These findings suggest a model wherein ATP binding drives FtsA polymerization and membrane remodeling at the lipid surface, and FtsA polymerization is coregulated with FtsZ polymerization. We conclude that the coordinated assembly of FtsZ and FtsA polymers may serve as a key checkpoint in division that triggers cell wall synthesis and division progression.
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Affiliation(s)
- Josiah J Morrison
- Department of Cell & Molecular Biology, The University of Rhode Island, Kingston, Rhode Island, USA
| | - Joseph Conti
- Department of Cell & Molecular Biology, The University of Rhode Island, Kingston, Rhode Island, USA
| | - Jodi L Camberg
- Department of Cell & Molecular Biology, The University of Rhode Island, Kingston, Rhode Island, USA.
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Ramos-León F, Ramamurthi K. Cytoskeletal proteins: Lessons learned from bacteria. Phys Biol 2022; 19. [PMID: 35081523 DOI: 10.1088/1478-3975/ac4ef0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/26/2022] [Indexed: 11/11/2022]
Abstract
Cytoskeletal proteins are classified as a group that is defined functionally, whose members are capable of polymerizing into higher order structures, either dynamically or statically, to perform structural roles during a variety of cellular processes. In eukaryotes, the most well-studied cytoskeletal proteins are actin, tubulin, and intermediate filaments, and are essential for cell shape and movement, chromosome segregation, and intracellular cargo transport. Prokaryotes often harbor homologs of these proteins, but in bacterial cells, these homologs are usually not employed in roles that can be strictly defined as "cytoskeletal". However, several bacteria encode other proteins capable of polymerizing which, although they do not appear to have a eukaryotic counterpart, nonetheless appear to perform a more traditional "cytoskeletal" function. In this review, we discuss recent reports that cover the structure and functions of prokaryotic proteins that are broadly termed as cytoskeletal, either by sequence homology or by function, to highlight how the enzymatic properties of traditionally studied cytoskeletal proteins may be used for other types of cellular functions; and to demonstrate how truly "cytoskeletal" functions may be performed by uniquely bacterial proteins that do not display homology to eukaryotic proteins.
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Affiliation(s)
- Félix Ramos-León
- National Institutes of Health, 37 Convent Dr., Bldg 37, Room 5132, Bethesda, Maryland, 20892, UNITED STATES
| | - Kumaran Ramamurthi
- Laboratory of Molecular Biology, National Cancer Institute, 37 Convent Dr, Bldg 37, Room 5132, Bethesda, Maryland, 20892, UNITED STATES
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35
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Abstract
In most bacteria, cell division is centrally organized by the FtsZ protein, which assembles into dynamic filaments at the division site along the cell membrane that interact with other key cell division proteins. In gammaproteobacteria such as Escherichia coli, FtsZ filaments are anchored to the cell membrane by two essential proteins, FtsA and ZipA. Canonically, this interaction was believed to be mediated solely by the FtsZ C-terminal peptide (CTP) domain that interacts with these and several other regulatory proteins. However, we now provide evidence of a second interaction between FtsZ and ZipA. Using site-specific photoactivated cross-linking, we identified a noncanonical FtsZ-binding site on ZipA on the opposite side from the FtsZ CTP-binding pocket. Cross-linking at this site was unaffected by the truncation of the FtsZ linker and CTP domains, indicating that this noncanonical site must interact directly with the globular core domain of FtsZ. Mutations introduced into either the canonical or noncanonical binding sites on ZipA disrupted photo-cross-linking with FtsZ and normal ZipA function in cell division, suggesting that both binding modes are important for normal cell growth and division. One mutation at the noncanonical face was also found to suppress defects of several other canonical and noncanonical site mutations in ZipA, suggesting there is some interdependence between the two sites. Taken together, these results suggest that ZipA employs a two-pronged FtsZ-binding mechanism. IMPORTANCE The tubulin homolog FtsZ plays a central early role in organizing bacterial cell division proteins at the cytoplasmic membrane. However, FtsZ does not directly interact with the membrane itself, instead relying on proteins such as FtsA to tether it to the membrane. In gammaproteobacteria, ZipA serves as a second essential membrane anchor along with FtsA. Although FtsA has a unique role in activating synthesis of the cell division septum, and ZipA may in turn activate FtsA, it was thought that both proteins interacted only with the conserved C terminus of FtsZ and were essentially interchangeable in their ability to tether FtsZ to the membrane. Here we challenge this view, providing evidence that ZipA directly contacts both the C terminus and the core domain of FtsZ. Such a two-pronged interaction between ZipA and FtsZ suggests that ZipA and FtsA may serve distinct membrane-anchoring roles for FtsZ.
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36
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Briggs NS, Bruce KE, Naskar S, Winkler ME, Roper DI. The Pneumococcal Divisome: Dynamic Control of Streptococcus pneumoniae Cell Division. Front Microbiol 2021; 12:737396. [PMID: 34737730 PMCID: PMC8563077 DOI: 10.3389/fmicb.2021.737396] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 09/15/2021] [Indexed: 12/14/2022] Open
Abstract
Cell division in Streptococcus pneumoniae (pneumococcus) is performed and regulated by a protein complex consisting of at least 14 different protein elements; known as the divisome. Recent findings have advanced our understanding of the molecular events surrounding this process and have provided new understanding of the mechanisms that occur during the division of pneumococcus. This review will provide an overview of the key protein complexes and how they are involved in cell division. We will discuss the interaction of proteins in the divisome complex that underpin the control mechanisms for cell division and cell wall synthesis and remodelling that are required in S. pneumoniae, including the involvement of virulence factors and capsular polysaccharides.
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Affiliation(s)
- Nicholas S. Briggs
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Kevin E. Bruce
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Souvik Naskar
- Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Malcolm E. Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - David I. Roper
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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Phillips DA, Zacharoff LA, Hampton CM, Chong GW, Malanoski AP, Metskas LA, Xu S, Bird LJ, Eddie BJ, Miklos AE, Jensen GJ, Drummy LF, El-Naggar MY, Glaven SM. A bacterial membrane sculpting protein with BAR domain-like activity. eLife 2021; 10:60049. [PMID: 34643180 PMCID: PMC8687657 DOI: 10.7554/elife.60049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Abstract
Bin/Amphiphysin/RVS (BAR) domain proteins belong to a superfamily of coiled-coil proteins influencing membrane curvature in eukaryotes and are associated with vesicle biogenesis, vesicle-mediated protein trafficking, and intracellular signaling. Here, we report a bacterial protein with BAR domain-like activity, BdpA, from Shewanella oneidensis MR-1, known to produce redox-active membrane vesicles and micrometer-scale outer membrane extensions (OMEs). BdpA is required for uniform size distribution of membrane vesicles and influences scaffolding of OMEs into a consistent diameter and curvature. Cryo-TEM reveals that a strain lacking BdpA produces lobed, disordered OMEs rather than membrane tubules or narrow chains produced by the wild-type strain. Overexpression of BdpA promotes OME formation during planktonic growth of S. oneidensis where they are not typically observed. Heterologous expression results in OME production in Marinobacter atlanticus and Escherichia coli. Based on the ability of BdpA to alter membrane architecture in vivo, we propose that BdpA and its homologs comprise a newly identified class of bacterial BAR domain-like proteins.
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Affiliation(s)
- Daniel A Phillips
- Oak Ridge Institute for Science and Education / US Army DEVCOM Chemical Biological Center, Aberdeen Proving Grounds, United States
| | - Lori A Zacharoff
- Department of Physics and Astronomy, University of Southern California, Los Angeles, United States
| | - Cheri M Hampton
- Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, United States
| | - Grace W Chong
- Department of Biological Sciences, University of Southern California, Los Angeles, United States
| | - Anthony P Malanoski
- Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, United States
| | - Lauren Ann Metskas
- Biological Sciences, Chemistry, California Institute of Technology, Pasadena, United States
| | - Shuai Xu
- Department of Physics and Astronomy, University of Southern California, Los Angeles, United States
| | - Lina J Bird
- Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, United States
| | - Brian J Eddie
- Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, United States
| | - Aleksandr E Miklos
- BioSciences Division, BioChemistry Branch, US Army DEVCOM Chemical Biological Center, Aberdeen Proving Ground, United States
| | - Grant J Jensen
- Biology and Bioengineering, California Institute of Technology, Pasadena, United States
| | - Lawrence F Drummy
- Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, United States
| | - Mohamed Y El-Naggar
- Department of Physics and Astronomy, Biological Sciences, and Chemistry, University of Southern California, Los Angeles, United States
| | - Sarah M Glaven
- Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, United States
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The archaeal protein SepF is essential for cell division in Haloferax volcanii. Nat Commun 2021; 12:3469. [PMID: 34103513 PMCID: PMC8187382 DOI: 10.1038/s41467-021-23686-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 05/07/2021] [Indexed: 02/05/2023] Open
Abstract
In most bacteria, cell division depends on the tubulin homolog FtsZ and other proteins, such as SepF, that form a complex termed the divisome. Cell division also depends on FtsZ in many archaea, but other components of the divisome are unknown. Here, we demonstrate that a SepF homolog plays important roles in cell division in Haloferax volcanii, a halophilic archaeon that is known to have two FtsZ homologs with slightly different functions (FtsZ1 and FtsZ2). SepF co-localizes with both FtsZ1 and FtsZ2 at midcell. Attempts to generate a sepF deletion mutant were unsuccessful, suggesting an essential role. Indeed, SepF depletion leads to severe cell division defects and formation of large cells. Overexpression of FtsZ1-GFP or FtsZ2-GFP in SepF-depleted cells results in formation of filamentous cells with a high number of FtsZ1 rings, while the number of FtsZ2 rings is not affected. Pull-down assays support that SepF interacts with FtsZ2 but not with FtsZ1, although SepF appears delocalized in the absence of FtsZ1. Archaeal SepF homologs lack a glycine residue known to be important for polymerization and function in bacteria, and purified H. volcanii SepF forms dimers, suggesting that polymerization might not be important for the function of archaeal SepF.
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Khanna K, Lopez-Garrido J, Sugie J, Pogliano K, Villa E. Asymmetric localization of the cell division machinery during Bacillus subtilis sporulation. eLife 2021; 10:62204. [PMID: 34018921 PMCID: PMC8192124 DOI: 10.7554/elife.62204] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 05/10/2021] [Indexed: 12/15/2022] Open
Abstract
The Gram-positive bacterium Bacillus subtilis can divide via two modes. During vegetative growth, the division septum is formed at the midcell 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. Using cryo-electron tomography, genetics and fluorescence microscopy, we found that the organization of the division machinery is different in the two septa. While FtsAZ filaments, the major orchestrators of bacterial cell division, are present uniformly around the leading edge of the invaginating vegetative septa, they are only present on the mother cell side of the invaginating sporulation septa. We provide evidence suggesting that the different distribution and number of FtsAZ filaments impact septal thickness, causing vegetative septa to be thicker than sporulation septa already during constriction. Finally, we show that a sporulation-specific protein, SpoIIE, regulates asymmetric divisome localization and septal thickness during sporulation.
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Affiliation(s)
- Kanika Khanna
- Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Javier Lopez-Garrido
- Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Joseph Sugie
- Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Kit Pogliano
- Division of Biological Sciences, University of California San Diego, La Jolla, United States
| | - Elizabeth Villa
- Division of Biological Sciences, University of California San Diego, La Jolla, United States
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40
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Chlebicka K, Bonar E, Suder P, Ostyn E, Felden B, Wladyka B, Pinel-Marie ML. Impacts of the Type I Toxin-Antitoxin System, SprG1/SprF1, on Staphylococcus aureus Gene Expression. Genes (Basel) 2021; 12:genes12050770. [PMID: 34070083 PMCID: PMC8158120 DOI: 10.3390/genes12050770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 11/16/2022] Open
Abstract
Type I toxin-antitoxin (TA) systems are widespread genetic modules in bacterial genomes. They express toxic peptides whose overexpression leads to growth arrest or cell death, whereas antitoxins regulate the expression of toxins, acting as labile antisense RNAs. The Staphylococcus aureus (S. aureus) genome contains and expresses several functional type I TA systems, but their biological functions remain unclear. Here, we addressed and challenged experimentally, by proteomics, if the type I TA system, the SprG1/SprF1 pair, influences the overall gene expression in S. aureus. Deleted and complemented S. aureus strains were analyzed for their proteomes, both intracellular and extracellular, during growth. Comparison of intracellular proteomes among the strains points to the SprF1 antitoxin as moderately downregulating protein expression. In the strain naturally expressing the SprG1 toxin, cytoplasmic proteins are excreted into the medium, but this is not due to unspecific cell leakages. Such a toxin-driven release of the cytoplasmic proteins may modulate the host inflammatory response that, in turn, could amplify the S. aureus infection spread.
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Affiliation(s)
- Kinga Chlebicka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
| | - Emilia Bonar
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
| | - Piotr Suder
- Department of Analytical Chemistry and Biochemistry, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 31-007 Krakow, Poland;
| | - Emeline Ostyn
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
| | - Brice Felden
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
| | - Benedykt Wladyka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
- Correspondence: (B.W.); (M.-L.P.-M.); Tel.: +48-126646511 (B.W.); +33-223234850 (M.-L.P.-M.)
| | - Marie-Laure Pinel-Marie
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
- Correspondence: (B.W.); (M.-L.P.-M.); Tel.: +48-126646511 (B.W.); +33-223234850 (M.-L.P.-M.)
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The Chaperonin GroESL Facilitates Caulobacter crescentus Cell Division by Supporting the Functions of the Z-Ring Regulators FtsA and FzlA. mBio 2021; 12:mBio.03564-20. [PMID: 33947758 PMCID: PMC8262945 DOI: 10.1128/mbio.03564-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The highly conserved chaperonin GroESL performs a crucial role in protein folding; however, the essential cellular pathways that rely on this chaperone are underexplored. Loss of GroESL leads to severe septation defects in diverse bacteria, suggesting the folding function of GroESL may be integrated with the bacterial cell cycle at the point of cell division. Here, we describe new connections between GroESL and the bacterial cell cycle using the model organism Caulobacter crescentus. Using a proteomics approach, we identify candidate GroESL client proteins that become insoluble or are degraded specifically when GroESL folding is insufficient, revealing several essential proteins that participate in cell division and peptidoglycan biosynthesis. We demonstrate that other cell cycle events, such as DNA replication and chromosome segregation, are able to continue when GroESL folding is insufficient. We further find that deficiency of two FtsZ-interacting proteins, the bacterial actin homologue FtsA and the constriction regulator FzlA, mediate the GroESL-dependent block in cell division. Our data show that sufficient GroESL is required to maintain normal dynamics of the FtsZ scaffold and divisome functionality in C. crescentus. In addition to supporting divisome function, we show that GroESL is required to maintain the flow of peptidoglycan precursors into the growing cell wall. Linking a chaperone to cell division may be a conserved way to coordinate environmental and internal cues that signal when it is safe to divide.
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42
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Single-molecule imaging reveals that Z-ring condensation is essential for cell division in Bacillus subtilis. Nat Microbiol 2021; 6:553-562. [PMID: 33737746 PMCID: PMC8085161 DOI: 10.1038/s41564-021-00878-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 02/11/2021] [Indexed: 01/31/2023]
Abstract
Although many components of the cell division machinery in bacteria have been identified1,2, the mechanisms by which they work together to divide the cell remain poorly understood. Key among these components is the tubulin FtsZ, which forms a Z ring at the midcell. FtsZ recruits the other cell division proteins, collectively called the divisome, and the Z ring constricts as the cell divides. We applied live-cell single-molecule imaging to describe the dynamics of the divisome in detail, and to evaluate the individual roles of FtsZ-binding proteins (ZBPs), specifically FtsA and the ZBPs EzrA, SepF and ZapA, in cytokinesis. We show that the divisome comprises two subcomplexes that move differently: stationary ZBPs that transiently bind to treadmilling FtsZ filaments, and a moving complex that includes cell wall synthases. Our imaging analyses reveal that ZBPs bundle FtsZ filaments together and condense them into Z rings, and that this condensation is necessary for cytokinesis.
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43
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Zorrilla S, Monterroso B, Robles-Ramos MÁ, Margolin W, Rivas G. FtsZ Interactions and Biomolecular Condensates as Potential Targets for New Antibiotics. Antibiotics (Basel) 2021; 10:antibiotics10030254. [PMID: 33806332 PMCID: PMC7999717 DOI: 10.3390/antibiotics10030254] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/18/2022] Open
Abstract
FtsZ is an essential and central protein for cell division in most bacteria. Because of its ability to organize into dynamic polymers at the cell membrane and recruit other protein partners to form a “divisome”, FtsZ is a leading target in the quest for new antibacterial compounds. Strategies to potentially arrest the essential and tightly regulated cell division process include perturbing FtsZ’s ability to interact with itself and other divisome proteins. Here, we discuss the available methodologies to screen for and characterize those interactions. In addition to assays that measure protein-ligand interactions in solution, we also discuss the use of minimal membrane systems and cell-like compartments to better approximate the native bacterial cell environment and hence provide a more accurate assessment of a candidate compound’s potential in vivo effect. We particularly focus on ways to measure and inhibit under-explored interactions between FtsZ and partner proteins. Finally, we discuss recent evidence that FtsZ forms biomolecular condensates in vitro, and the potential implications of these assemblies in bacterial resistance to antibiotic treatment.
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Affiliation(s)
- Silvia Zorrilla
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
- Correspondence: (S.Z.); (B.M.); Tel.: +34-91-837-3112 (S.Z. & B.M.)
| | - Begoña Monterroso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
- Correspondence: (S.Z.); (B.M.); Tel.: +34-91-837-3112 (S.Z. & B.M.)
| | - Miguel-Ángel Robles-Ramos
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston, TX 77030, USA;
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain; (M.-Á.R.-R.); (G.R.)
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44
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Xiao X, Willemse J, Voskamp P, Li X, Prota AE, Lamers M, Pannu N, Abrahams JP, van Wezel GP. Ectopic positioning of the cell division plane is associated with single amino acid substitutions in the FtsZ-recruiting SsgB in Streptomyces. Open Biol 2021; 11:200409. [PMID: 33622102 PMCID: PMC8061694 DOI: 10.1098/rsob.200409] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In most bacteria, cell division begins with the polymerization of the GTPase FtsZ at mid-cell, which recruits the division machinery to initiate cell constriction. In the filamentous bacterium Streptomyces, cell division is positively controlled by SsgB, which recruits FtsZ to the future septum sites and promotes Z-ring formation. Here, we show that various amino acid (aa) substitutions in the highly conserved SsgB protein result in ectopically placed septa that sever spores diagonally or along the long axis, perpendicular to the division plane. Fluorescence microscopy revealed that between 3.3% and 9.8% of the spores of strains expressing SsgB E120 variants were severed ectopically. Biochemical analysis of SsgB variant E120G revealed that its interaction with FtsZ had been maintained. The crystal structure of Streptomyces coelicolor SsgB was resolved and the key residues were mapped on the structure. Notably, residue substitutions (V115G, G118V, E120G) that are associated with septum misplacement localize in the α2-α3 loop region that links the final helix and the rest of the protein. Structural analyses and molecular simulation revealed that these residues are essential for maintaining the proper angle of helix α3. Our data suggest that besides altering FtsZ, aa substitutions in the FtsZ-recruiting protein SsgB also lead to diagonally or longitudinally divided cells in Streptomyces.
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Affiliation(s)
- Xiansha Xiao
- Molecular Biotechnology, Leiden University, PO Box 9505, 2300RA Leiden, The Netherlands
| | - Joost Willemse
- Molecular Biotechnology, Leiden University, PO Box 9505, 2300RA Leiden, The Netherlands
| | - Patrick Voskamp
- Biophysical Structural Chemistry, Leiden University, PO Box 9502, 2300RA Leiden, The Netherlands
| | - Xinmeng Li
- LIC/Energy and Sustainability, Leiden University, PO Box 9502, 2300RA Leiden, The Netherlands
| | | | - Meindert Lamers
- Leiden University Medical Center, PO Box 9600, 2300RC Leiden, The Netherlands
| | - Navraj Pannu
- Biophysical Structural Chemistry, Leiden University, PO Box 9502, 2300RA Leiden, The Netherlands
| | - Jan Pieter Abrahams
- Molecular Biotechnology, Leiden University, PO Box 9505, 2300RA Leiden, The Netherlands.,Paul Scherrer Institute, CH-5232 Villigen, Switzerland.,Biozentrum, University of Basel, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | - Gilles P van Wezel
- Molecular Biotechnology, Leiden University, PO Box 9505, 2300RA Leiden, The Netherlands
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Fujita J, Sugiyama S, Terakado H, Miyazaki M, Ozawa M, Ueda N, Kuroda N, Tanaka SI, Yoshizawa T, Uchihashi T, Matsumura H. Dynamic Assembly/Disassembly of Staphylococcus aureus FtsZ Visualized by High-Speed Atomic Force Microscopy. Int J Mol Sci 2021; 22:ijms22041697. [PMID: 33567659 PMCID: PMC7914567 DOI: 10.3390/ijms22041697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 02/04/2021] [Indexed: 12/24/2022] Open
Abstract
FtsZ is a key protein in bacterial cell division and is assembled into filamentous architectures. FtsZ filaments are thought to regulate bacterial cell division and have been investigated using many types of imaging techniques such as atomic force microscopy (AFM), but the time scale of the method was too long to trace the filament formation process. Development of high-speed AFM enables us to achieve sub-second time resolution and visualize the formation and dissociation process of FtsZ filaments. The analysis of the growth and dissociation rates of the C-terminal truncated FtsZ (FtsZt) filaments indicate the net growth and dissociation of FtsZt filaments in the growth and dissociation conditions, respectively. We also analyzed the curvatures of the full-length FtsZ (FtsZf) and FtsZt filaments, and the comparative analysis indicated the straight-shape preference of the FtsZt filaments than those of FtsZf. These findings provide insights into the fundamental dynamic behavior of FtsZ protofilaments and bacterial cell division.
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Affiliation(s)
- Junso Fujita
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan;
| | - Shogo Sugiyama
- Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan;
| | - Haruna Terakado
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
| | - Maho Miyazaki
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
| | - Mayuki Ozawa
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
| | - Nanami Ueda
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
| | - Natsuko Kuroda
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
| | - Shun-ichi Tanaka
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Hangi-cho, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan
| | - Takuya Yoshizawa
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
| | - Takayuki Uchihashi
- Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan;
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan
- Correspondence: (T.U.); (H.M.); Tel.: +81-52-789-2885 (T.U.); +81-77-561-4809 (H.M.)
| | - Hiroyoshi Matsumura
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan; (H.T.); (M.M.); (M.O.); (N.U.); (N.K.); (S.-i.T.); (T.Y.)
- Correspondence: (T.U.); (H.M.); Tel.: +81-52-789-2885 (T.U.); +81-77-561-4809 (H.M.)
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Wenzel M, Celik Gulsoy IN, Gao Y, Teng Z, Willemse J, Middelkamp M, van Rosmalen MGM, Larsen PWB, van der Wel NN, Wuite GJL, Roos WH, Hamoen LW. Control of septum thickness by the curvature of SepF polymers. Proc Natl Acad Sci U S A 2021; 118:e2002635118. [PMID: 33443155 PMCID: PMC7812789 DOI: 10.1073/pnas.2002635118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Gram-positive bacteria divide by forming a thick cross wall. How the thickness of this septal wall is controlled is unknown. In this type of bacteria, the key cell division protein FtsZ is anchored to the cell membrane by two proteins, FtsA and/or SepF. We have isolated SepF homologs from different bacterial species and found that they all polymerize into large protein rings with diameters varying from 19 to 44 nm. Interestingly, these values correlated well with the thickness of their septa. To test whether ring diameter determines septal thickness, we tried to construct different SepF chimeras with the purpose to manipulate the diameter of the SepF protein ring. This was indeed possible and confirmed that the conserved core domain of SepF regulates ring diameter. Importantly, when SepF chimeras with different diameters were expressed in the bacterial host Bacillus subtilis, the thickness of its septa changed accordingly. These results strongly support a model in which septal thickness is controlled by curved molecular clamps formed by SepF polymers attached to the leading edge of nascent septa. This also implies that the intrinsic shape of a protein polymer can function as a mold to shape the cell wall.
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Affiliation(s)
- Michaela Wenzel
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Ilkay N Celik Gulsoy
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Yongqiang Gao
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Zihao Teng
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Joost Willemse
- Molecular Biotechnology, Institute of Biology, Leiden University, 2333 BE, Leiden, The Netherlands
| | - Martijn Middelkamp
- Molecular Biophysics, Zernike Institute, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Mariska G M van Rosmalen
- Department of Physics and Astronomy and Laser Lab, Free University of Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Per W B Larsen
- Department of Medical Biology, Electron Microscopy Center Amsterdam, Amsterdam UMC, 1105 AZ Amsterdam, The Netherlands
| | - Nicole N van der Wel
- Department of Medical Biology, Electron Microscopy Center Amsterdam, Amsterdam UMC, 1105 AZ Amsterdam, The Netherlands
| | - Gijs J L Wuite
- Department of Physics and Astronomy and Laser Lab, Free University of Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Wouter H Roos
- Molecular Biophysics, Zernike Institute, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Leendert W Hamoen
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
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47
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Mishra D, Pahujani S, Mitra N, Srivastava A, Srinivasan R. Identification of a Potential Membrane-Targeting Sequence in the C-Terminus of the F Plasmid Segregation Protein SopA. J Membr Biol 2021; 254:243-257. [PMID: 33427942 DOI: 10.1007/s00232-020-00157-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 11/11/2020] [Indexed: 10/22/2022]
Abstract
Stable maintenance and partitioning of the 'Fertility' plasmid or the F plasmid in its host Escherichia coli require the function of a ParA superfamily of proteins known as SopA. The mechanism by which SopA mediates plasmid segregation is well studied. SopA is a nucleoid-binding protein and binds DNA in an ATP-dependent but sequence non-specific manner. ATP hydrolysis stimulated by the binding of the SopBC complex mediates the release of SopA from the nucleoid. Cycles of ATP-binding and hydrolysis generate an ATPase gradient that moves the plasmid through a chemophoresis force. Nucleoid binding of SopA thus assumes a central role in its plasmid-partitioning function. However, earlier work also suggests that the F plasmid can be partitioned into anucleate cells, thus implicating nucleoid independent partitioning. Interestingly, SopA is also reported to be associated with the inner membrane of the bacteria. Here, we report the identification of a possible membrane-targeting sequence, a predicted amphipathic helix, at the C-terminus of SopA. Molecular dynamics simulations indicate that the predicted amphipathic helical motif of SopA has weak affinity for membranes. Moreover, we experimentally show that SopA can associate with bacterial membranes, is detectable in the membrane fractions of bacterial lysates, and is sensitive to the membrane potential. Further, unlike the wild-type SopA, a deletion of the C-terminal 29 amino acids results in the loss of F plasmids from bacterial cells.
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Affiliation(s)
- Dipika Mishra
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India
| | - Sakshi Pahujani
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India.,Molecular Biophysics Unit, Indian Institute of Science-Bangalore, C. V. Raman Road, Bangalore, Karnataka, 560012, India
| | - Nivedita Mitra
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India
| | - Anand Srivastava
- Molecular Biophysics Unit, Indian Institute of Science-Bangalore, C. V. Raman Road, Bangalore, Karnataka, 560012, India.
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institutes, Bhubaneswar, Odisha, 752050, India.
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48
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Abstract
The division and cell wall (dcw) cluster is a highly conserved region of the bacterial genome consisting of genes that encode several cell division and cell wall synthesis factors, including the central division protein FtsZ. The region immediately downstream of ftsZ encodes the ylm genes and is conserved across diverse lineages of Gram-positive bacteria and Cyanobacteria In some organisms, this region remains part of the dcw cluster, but in others, it appears as an independent operon. A well-studied protein coded from this region is the positive FtsZ regulator SepF (YlmF), which anchors FtsZ to the membrane. Recent developments have shed light on the importance of SepF in a range of species. Additionally, new studies are highlighting the importance of the other conserved genes in this neighborhood. In this minireview, we aim to bring together the current research linking the ylm region to cell division and highlight further questions surrounding these conserved genes.
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49
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Simulations of Proposed Mechanisms of FtsZ-Driven Cell Constriction. J Bacteriol 2021; 203:JB.00576-20. [PMID: 33199285 PMCID: PMC7811198 DOI: 10.1128/jb.00576-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 10/26/2020] [Indexed: 01/24/2023] Open
Abstract
FtsZ is thought to generate constrictive force to divide the cell, possibly via one of two predominant models in the field. In one, FtsZ filaments overlap to form complete rings which constrict as filaments slide past each other to maximize lateral contact. To divide, bacteria must constrict their membranes against significant force from turgor pressure. A tubulin homolog, FtsZ, is thought to drive constriction, but how FtsZ filaments might generate constrictive force in the absence of motor proteins is not well understood. There are two predominant models in the field. In one, FtsZ filaments overlap to form complete rings around the circumference of the cell, and attractive forces cause filaments to slide past each other to maximize lateral contact. In the other, filaments exert force on the membrane by a GTP-hydrolysis-induced switch in conformation from straight to bent. Here, we developed software, ZCONSTRICT, for quantitative three-dimensional (3D) simulations of Gram-negative bacterial cell division to test these two models and identify critical conditions required for them to work. We find that the avidity of any kind of lateral interactions quickly halts the sliding of filaments, so a mechanism such as depolymerization or treadmilling is required to sustain constriction by filament sliding. For filament bending, we find that a mechanism such as the presence of a rigid linker is required to constrain bending to within the division plane and maintain the distance observed in vivo between the filaments and the membrane. Of these two models, only the filament bending model is consistent with our lab’s recent observation of constriction associated with a single, short FtsZ filament. IMPORTANCE FtsZ is thought to generate constrictive force to divide the cell, possibly via one of two predominant models in the field. In one, FtsZ filaments overlap to form complete rings which constrict as filaments slide past each other to maximize lateral contact. In the other, filaments exert force on the membrane by switching conformation from straight to bent. Here, we developed software, ZCONSTRICT, for three-dimensional (3D) simulations to test these two models. We find that a mechanism such as depolymerization or treadmilling are required to sustain constriction by filament sliding. For filament bending, we find that a mechanism that constrains bending to within the division plane is required to maintain the distance observed in vivo between the filaments and the membrane.
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50
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Isolation of a member of the candidate phylum 'Atribacteria' reveals a unique cell membrane structure. Nat Commun 2020; 11:6381. [PMID: 33318506 PMCID: PMC7736352 DOI: 10.1038/s41467-020-20149-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/04/2020] [Indexed: 11/11/2022] Open
Abstract
A key feature that differentiates prokaryotic cells from eukaryotes is the absence of an intracellular membrane surrounding the chromosomal DNA. Here, we isolate a member of the ubiquitous, yet-to-be-cultivated phylum ‘Candidatus Atribacteria’ (also known as OP9) that has an intracytoplasmic membrane apparently surrounding the nucleoid. The isolate, RT761, is a subsurface-derived anaerobic bacterium that appears to have three lipid membrane-like layers, as shown by cryo-electron tomography. Our observations are consistent with a classical gram-negative structure with an additional intracytoplasmic membrane. However, further studies are needed to provide conclusive evidence for this unique intracellular structure. The RT761 genome encodes proteins with features that might be related to the complex cellular structure, including: N-terminal extensions in proteins involved in important processes (such as cell-division protein FtsZ); one of the highest percentages of transmembrane proteins among gram-negative bacteria; and predicted Sec-secreted proteins with unique signal peptides. Physiologically, RT761 primarily produces hydrogen for electron disposal during sugar degradation, and co-cultivation with a hydrogen-scavenging methanogen improves growth. We propose RT761 as a new species, Atribacter laminatus gen. nov. sp. nov. and a new phylum, Atribacterota phy. nov. A key feature that differentiates prokaryotic cells from eukaryotes is the absence of an intracellular membrane surrounding the chromosomal DNA. Here, the authors isolate a member of the ubiquitous, yet-to-be-cultivated bacterial phylum ‘Candidatus Atribacteria’ that has an intracytoplasmic membrane apparently surrounding the nucleoid.
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