1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Henriksen C, Baek KT, Wacnik K, Gallay C, Veening JW, Foster SJ, Frees D. The ClpX chaperone and a hypermorphic FtsA variant with impaired self-interaction are mutually compensatory for coordinating Staphylococcus aureus cell division. Mol Microbiol 2024; 121:98-115. [PMID: 38041395 DOI: 10.1111/mmi.15200] [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: 08/28/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 12/03/2023]
Abstract
Bacterial cell division requires the coordinated assembly and disassembly of a large protein complex called the divisome; however, the exact role of molecular chaperones in this critical process remains unclear. We here provide genetic evidence that ClpX unfoldase activity is a determinant for proper coordination of bacterial cell division by showing the growth defect of a Staphylococcus aureus clpX mutant is rescued by a spontaneously acquired G325V substitution in the ATP-binding domain of the essential FtsA cell division protein. The polymerization state of FtsA is thought to control initiation of bacterial septum synthesis and, while restoring the aberrant FtsA dynamics in clpX cells, the FtsAG325V variant displayed reduced ability to interact with itself and other cell division proteins. In wild-type cells, the ftsAG325V allele shared phenotypes with Escherichia coli superfission ftsA mutants and accelerated the cell cycle, increased the risk of daughter cell lysis, and conferred sensitivity to heat and antibiotics inhibiting cell wall synthesis. Strikingly, lethality was mitigated by spontaneous mutations that inactivate ClpX. Taken together, our results suggest that ClpX promotes septum synthesis by antagonizing FtsA interactions and illuminates the critical role of a protein unfoldase in coordinating bacterial cell division.
Collapse
Affiliation(s)
- Camilla Henriksen
- Department of Veterinary and Animal Disease, University of Copenhagen, Frederiksberg, Denmark
| | - Kristoffer T Baek
- Department of Veterinary and Animal Disease, University of Copenhagen, Frederiksberg, Denmark
| | | | - Clement Gallay
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Simon J Foster
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Dorte Frees
- Department of Veterinary and Animal Disease, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Lamanna MM, Manzoor I, Joseph M, Ye ZA, Benedet M, Zanardi A, Ren Z, Wang X, Massidda O, Tsui HT, Winkler ME. Roles of RodZ and class A PBP1b in the assembly and regulation of the peripheral peptidoglycan elongasome in ovoid-shaped cells of Streptococcus pneumoniae D39. Mol Microbiol 2022; 118:336-368. [PMID: 36001060 PMCID: PMC9804626 DOI: 10.1111/mmi.14969] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/30/2022] [Accepted: 08/02/2022] [Indexed: 01/17/2023]
Abstract
RodZ of rod-shaped bacteria functions to link MreB filaments to the Rod peptidoglycan (PG) synthase complex that moves circumferentially perpendicular to the long cell axis, creating hoop-like sidewall PG. Ovoid-shaped bacteria, such as Streptococcus pneumoniae (pneumococcus; Spn) that lack MreB, use a different modality for peripheral PG elongation that emanates from the midcell of dividing cells. Yet, S. pneumoniae encodes a RodZ homolog similar to RodZ in rod-shaped bacteria. We show here that the helix-turn-helix and transmembrane domains of RodZ(Spn) are essential for growth at 37°C. ΔrodZ mutations are suppressed by Δpbp1a, mpgA(Y488D), and ΔkhpA mutations that suppress ΔmreC, but not ΔcozE. Consistent with a role in PG elongation, RodZ(Spn) co-localizes with MreC and aPBP1a throughout the cell cycle and forms complexes and interacts with PG elongasome proteins and regulators. Depletion of RodZ(Spn) results in aberrantly shaped, non-growing cells and mislocalization of elongasome proteins MreC, PBP2b, and RodA. Moreover, Tn-seq reveals that RodZ(Spn), but not MreCD(Spn), displays a specific synthetic-viable genetic relationship with aPBP1b, whose function is unknown. We conclude that RodZ(Spn) acts as a scaffolding protein required for elongasome assembly and function and that aPBP1b, like aPBP1a, plays a role in elongasome regulation and possibly peripheral PG synthesis.
Collapse
Affiliation(s)
- Melissa M. Lamanna
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Irfan Manzoor
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Merrin Joseph
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Ziyun A. Ye
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Mattia Benedet
- Department of Cellular, Computational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Alessia Zanardi
- Department of Cellular, Computational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Zhongqing Ren
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Xindan Wang
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology (CIBIO)University of TrentoTrentoItaly
| | - Ho‐Ching T. Tsui
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| | - Malcolm E. Winkler
- Department of BiologyIndiana University BloomingtonBloomingtonIndianaUSA
| |
Collapse
|
5
|
Alcorlo M, Martínez-Caballero S, Molina R, Hermoso JA. Regulation of Lytic Machineries by the FtsEX Complex in the Bacterial Divisome. Subcell Biochem 2022; 99:285-315. [PMID: 36151380 DOI: 10.1007/978-3-031-00793-4_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The essential membrane complex FtsE/FtsX (FtsEX), belonging to the ABC transporter superfamily and widespread among bacteria, plays a relevant function in some crucial cell wall remodeling processes such as cell division, elongation, or sporulation. FtsEX plays a double role by recruiting proteins to the divisome apparatus and by regulating lytic activity of the cell wall hydrolases required for daughter cell separation. Interestingly, FtsEX does not act as a transporter but uses the ATPase activity of FtsE to mechanically transmit a signal from the cytosol, through the membrane, to the periplasm that activates the attached hydrolases. While the complete molecular details of such mechanism are not yet known, evidence has been recently reported that clarify essential aspects of this complex system. In this chapter we will present recent structural advances on this topic. The three-dimensional structure of FtsE, FtsX, and some of the lytic enzymes or their cognate regulators revealed an unexpected scenario in which a delicate set of intermolecular interactions, conserved among different bacterial genera, could be at the core of this regulatory mechanism providing exquisite control in both space and time of this central process to assist bacterial survival.
Collapse
Affiliation(s)
- Martín Alcorlo
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain
| | - Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain
- Department of Chemistry of Biomacromolecules, Universidade Nacional Autonoma de Mexico, Ciudad de México, Mexico
| | - Rafael Molina
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, Madrid, Spain.
| |
Collapse
|
6
|
Perez AJ, Villicana JB, Tsui HCT, Danforth ML, Benedet M, Massidda O, Winkler ME. FtsZ-Ring Regulation and Cell Division Are Mediated by Essential EzrA and Accessory Proteins ZapA and ZapJ in Streptococcus pneumoniae. Front Microbiol 2021; 12:780864. [PMID: 34938281 PMCID: PMC8687745 DOI: 10.3389/fmicb.2021.780864] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 10/22/2021] [Indexed: 12/02/2022] Open
Abstract
The bacterial FtsZ-ring initiates division by recruiting a large repertoire of proteins (the divisome; Z-ring) needed for septation and separation of cells. Although FtsZ is essential and its role as the main orchestrator of cell division is conserved in most eubacteria, the regulators of Z-ring presence and positioning are not universal. This study characterizes factors that regulate divisome presence and placement in the ovoid-shaped pathogen, Streptococcus pneumoniae (Spn), focusing on FtsZ, EzrA, SepF, ZapA, and ZapJ, which is reported here as a partner of ZapA. Epi-fluorescence microscopy (EFm) and high-resolution microscopy experiments showed that FtsZ and EzrA co-localize during the entire Spn cell cycle, whereas ZapA and ZapJ are late-arriving divisome proteins. Depletion and conditional mutants demonstrate that EzrA is essential in Spn and required for normal cell growth, size, shape homeostasis, and chromosome segregation. Moreover, EzrA(Spn) is required for midcell placement of FtsZ-rings and PG synthesis. Notably, overexpression of EzrA leads to the appearance of extra Z-rings in Spn. Together, these observations support a role for EzrA as a positive regulator of FtsZ-ring formation in Spn. Conversely, FtsZ is required for EzrA recruitment to equatorial rings and for the organization of PG synthesis. In contrast to EzrA depletion, which causes a bacteriostatic phenotype in Spn, depletion of FtsZ results in enlarged spherical cells that are subject to LytA-dependent autolysis. Co-immunoprecipitation and bacterial two-hybrid assays show that EzrA(Spn) is in complexes with FtsZ, Z-ring regulators (FtsA, SepF, ZapA, MapZ), division proteins (FtsK, StkP), and proteins that mediate peptidoglycan synthesis (GpsB, aPBP1a), consistent with a role for EzrA at the interface of cell division and PG synthesis. In contrast to the essentiality of FtsZ and EzrA, ZapA and SepF have accessory roles in regulating pneumococcal physiology. We further show that ZapA interacts with a non-ZapB homolog, named here as ZapJ, which is conserved in Streptococcus species. The absence of the accessory proteins, ZapA, ZapJ, and SepF, exacerbates growth defects when EzrA is depleted or MapZ is deleted. Taken together, these results provide new information about the spatially and temporally distinct proteins that regulate FtsZ-ring organization and cell division in Spn.
Collapse
Affiliation(s)
- Amilcar J Perez
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Jesus Bazan Villicana
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Ho-Ching T Tsui
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Madeline L Danforth
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| | - Mattia Benedet
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, United States
| |
Collapse
|
7
|
Peters K, Schweizer I, Hakenbeck R, Denapaite D. New Insights into Beta-Lactam Resistance of Streptococcus pneumoniae: Serine Protease HtrA Degrades Altered Penicillin-Binding Protein 2x. Microorganisms 2021; 9:microorganisms9081685. [PMID: 34442764 PMCID: PMC8400419 DOI: 10.3390/microorganisms9081685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/02/2021] [Accepted: 08/04/2021] [Indexed: 11/18/2022] Open
Abstract
Reduced amounts of the essential penicillin-binding protein 2x (PBP2x) were detected in two cefotaxime-resistant Streptococcus pneumoniae laboratory mutants C405 and C606. These mutants contain two or four mutations in the penicillin-binding domain of PBP2x, respectively. The transcription of the pbp2x gene was not affected in both mutants; thus, the reduced PBP2x amounts were likely due to post-transcriptional regulation. The mutants carry a mutation in the histidine protein kinase gene ciaH, resulting in enhanced gene expression mediated by the cognate response regulator CiaR. Deletion of htrA, encoding a serine protease regulated by CiaR, or inactivation of HtrA proteolytic activity showed that HtrA is indeed responsible for PBP2x degradation in both mutants, and that this affects β-lactam resistance. Depletion of the PBP2xC405 in different genetic backgrounds confirmed that HtrA degrades PBP2xC405. A GFP-PBP2xC405 fusion protein still localized at the septum in the absence of HtrA. The complementation studies in HtrA deletion strains showed that HtrA can be overexpressed in pneumococcal cells to specific levels, depending on the genetic background. Quantitative Western blotting revealed that the PBP2x amount in C405 strain was less than 20% compared to parental strain, suggesting that PBP2x is an abundant protein in S. pneumoniae R6 strain.
Collapse
|
8
|
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.
Collapse
|
9
|
McCausland JW, Yang X, Squyres GR, Lyu Z, Bruce KE, Lamanna MM, Söderström B, Garner EC, Winkler ME, Xiao J, Liu J. Treadmilling FtsZ polymers drive the directional movement of sPG-synthesis enzymes via a Brownian ratchet mechanism. Nat Commun 2021; 12:609. [PMID: 33504807 PMCID: PMC7840769 DOI: 10.1038/s41467-020-20873-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/15/2020] [Indexed: 01/30/2023] Open
Abstract
The FtsZ protein is a central component of the bacterial cell division machinery. It polymerizes at mid-cell and recruits more than 30 proteins to assemble into a macromolecular complex to direct cell wall constriction. FtsZ polymers exhibit treadmilling dynamics, driving the processive movement of enzymes that synthesize septal peptidoglycan (sPG). Here, we combine theoretical modelling with single-molecule imaging of live bacterial cells to show that FtsZ's treadmilling drives the directional movement of sPG enzymes via a Brownian ratchet mechanism. The processivity of the directional movement depends on the binding potential between FtsZ and the sPG enzyme, and on a balance between the enzyme's diffusion and FtsZ's treadmilling speed. We propose that this interplay may provide a mechanism to control the spatiotemporal distribution of active sPG enzymes, explaining the distinct roles of FtsZ treadmilling in modulating cell wall constriction rate observed in different bacteria.
Collapse
Affiliation(s)
- Joshua W McCausland
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Xinxing Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Georgia R Squyres
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Zhixin Lyu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Kevin E Bruce
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Melissa M Lamanna
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Bill Söderström
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Ethan C Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
| | - Jian Liu
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
| |
Collapse
|
10
|
Singhi D, Srivastava P. How similar or dissimilar cells are produced by bacterial cell division? Biochimie 2020; 176:71-84. [DOI: 10.1016/j.biochi.2020.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 10/24/2022]
|
11
|
Silber N, Matos de Opitz CL, Mayer C, Sass P. Cell division protein FtsZ: from structure and mechanism to antibiotic target. Future Microbiol 2020; 15:801-831. [DOI: 10.2217/fmb-2019-0348] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Antimicrobial resistance to virtually all clinically applied antibiotic classes severely limits the available options to treat bacterial infections. Hence, there is an urgent need to develop and evaluate new antibiotics and targets with resistance-breaking properties. Bacterial cell division has emerged as a new antibiotic target pathway to counteract multidrug-resistant pathogens. New approaches in antibiotic discovery and bacterial cell biology helped to identify compounds that either directly interact with the major cell division protein FtsZ, thereby perturbing the function and dynamics of the cell division machinery, or affect the structural integrity of FtsZ by inducing its degradation. The impressive antimicrobial activities and resistance-breaking properties of certain compounds validate the inhibition of bacterial cell division as a promising strategy for antibiotic intervention.
Collapse
Affiliation(s)
- Nadine Silber
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | - Cruz L Matos de Opitz
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | - Christian Mayer
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
| | - Peter Sass
- Department of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology & Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, Tübingen 72076, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen 72076, Germany
| |
Collapse
|
12
|
FtsA-FtsZ interaction in Vibrio cholerae causes conformational change of FtsA resulting in inhibition of ATP hydrolysis and polymerization. Int J Biol Macromol 2019; 142:18-32. [PMID: 31790740 DOI: 10.1016/j.ijbiomac.2019.11.217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 11/26/2019] [Accepted: 11/26/2019] [Indexed: 11/23/2022]
Abstract
Proper interaction between the divisome proteins FtsA and FtsZ is important for the bacterial cell division which is not well characterized till date. In this study, the objective was to understand the mechanism of FtsA-FtsZ interaction using full-length recombinant proteins. We cloned, over-expressed, purified and subsequently characterized FtsA of Vibrio cholerae (VcFtsA). We found that VcFtsA polymerization assembly was dependent on Ca2+ ions, which is unique among FtsA proteins reported until now. VcFtsA also showed ATPase activity and its assembly was ATP dependent. Binding parameters of the interaction between the two full-length proteins, VcFtsA, and VcFtsZ determined by fluorescence spectrophotometry yielded a Kd value of around 38 μM. The Kd value of the interaction was 3 μM when VcFtsA was in ATP bound state. We found that VcFtsZ after interacting with VcFtsA causes a change of secondary structure in the later one leading to loss of its ability to hydrolyze ATP, subsequently halting the VcFtsA polymerization. On the other hand, a double-mutant of VcFtsA (VcFtsA-D242E,R300E), that does not bind to VcFtsZ, polymerized in the presence of VcFtsZ. Though FtsA proteins among different organisms show 70-80% homology in their sequences, assembly of VcFtsA showed a difference in its regulatory processes.
Collapse
|
13
|
Vollmer W, Massidda O, Tomasz A. The Cell Wall of Streptococcus pneumoniae. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0018-2018. [PMID: 31172911 PMCID: PMC11026078 DOI: 10.1128/microbiolspec.gpp3-0018-2018] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Indexed: 12/13/2022] Open
Abstract
Streptococcus pneumoniae has a complex cell wall that plays key roles in cell shape maintenance, growth and cell division, and interactions with components of the human host. The peptidoglycan has a heterogeneous composition with more than 50 subunits (muropeptides)-products of several peptidoglycan-modifying enzymes. The amidation of glutamate residues in the stem peptide is needed for efficient peptide cross-linking, and peptides with a dipeptide branch prevail in some beta-lactam-resistant strains. The glycan strands are modified by deacetylation of N-acetylglucosamine residues and O-acetylation of N-acetylmuramic acid residues, and both modifications contribute to pneumococcal resistance to lysozyme. The glycan strands carry covalently attached wall teichoic acid and capsular polysaccharide. Pneumococci are unique in that the wall teichoic acid and lipoteichoic acid contain the same unusually complex repeating units decorated with phosphoryl choline residues, which anchor the choline-binding proteins. The structures of lipoteichoic acid and the attachment site of wall teichoic acid to peptidoglycan have recently been revised. During growth, pneumococci assemble their cell walls at midcell in coordinated rounds of cell elongation and division, leading to the typical ovococcal cell shape. Cell wall growth depends on the cytoskeletal FtsA and FtsZ proteins and is regulated by several morphogenesis proteins that also show patterns of dynamic localization at midcell. Some of the key regulators are phosphorylated by StkP and dephosphorylated by PhpP to facilitate robust selection of the division site and plane and to maintain cell shape.
Collapse
Affiliation(s)
- Waldemar Vollmer
- Institute for Cell and Molecular Biosciences, The Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Orietta Massidda
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | | |
Collapse
|
14
|
Roles of the DedD Protein in Escherichia coli Cell Constriction. J Bacteriol 2019; 201:JB.00698-18. [PMID: 30692172 DOI: 10.1128/jb.00698-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/20/2019] [Indexed: 02/04/2023] Open
Abstract
Two key tasks of the bacterial septal-ring (SR) machinery during cell constriction are the generation of an inward-growing annulus of septal peptidoglycan (sPG) and the concomitant splitting of its outer edge into two layers of polar PG that will be inherited by the two new cell ends. FtsN is an essential SR protein that helps trigger the active constriction phase in Escherichia coli by inducing a self-enhancing cycle of processes that includes both sPG synthesis and splitting and that we refer to as the sPG loop. DedD is an SR protein that resembles FtsN in several ways. Both are bitopic inner membrane proteins with small N-terminal cytoplasmic parts and larger periplasmic parts that terminate with a SPOR domain. Though absence of DedD normally causes a mild cell-chaining phenotype, the protein is essential for division and survival of cells with limited FtsN activity. Here, we find that a small N-terminal portion of DedD (NDedD; DedD1-54) is required and sufficient to suppress ΔdedD-associated division phenotypes, and we identify residues within its transmembrane domain that are particularly critical to DedD function. Further analyses indicate that DedD and FtsN act in parallel to promote sPG synthesis, possibly by engaging different parts of the FtsBLQ subcomplex to induce a conformation that permits and/or stimulates the activity of sPG synthase complexes composed of FtsW, FtsI (PBP3), and associated proteins. We propose that, like FtsN, DedD promotes cell fission by stimulating sPG synthesis, as well as by providing positive feedback to the sPG loop.IMPORTANCE Cell division (cytokinesis) is a fundamental biological process that is incompletely understood for any organism. Division of bacterial cells relies on a ring-like machinery called the septal ring or divisome that assembles along the circumference of the mother cell at the site where constriction eventually occurs. In the well-studied bacterium Escherichia coli, this machinery contains over 30 distinct proteins. We identify functionally important parts of one of these proteins, DedD, and present evidence supporting a role for DedD in helping to induce and/or sustain a self-enhancing cycle of processes that are executed by fellow septal-ring proteins and that drive the active constriction phase of the cell division cycle.
Collapse
|
15
|
Direct Interaction between the Two Z Ring Membrane Anchors FtsA and ZipA. J Bacteriol 2019; 201:JB.00579-18. [PMID: 30478085 DOI: 10.1128/jb.00579-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/19/2018] [Indexed: 12/14/2022] Open
Abstract
The initiation of Escherichia coli cell division requires three proteins, FtsZ, FtsA, and ZipA, which assemble in a dynamic ring-like structure at midcell. Along with the transmembrane protein ZipA, the actin-like FtsA helps to tether treadmilling polymers of tubulin-like FtsZ to the membrane. In addition to forming homo-oligomers, FtsA and ZipA interact directly with the C-terminal conserved domain of FtsZ. Gain-of-function mutants of FtsA are deficient in forming oligomers and can bypass the need for ZipA, suggesting that ZipA may normally function to disrupt FtsA oligomers, although no direct interaction between FtsA and ZipA has been reported. Here, we use in vivo cross-linking to show that FtsA and ZipA indeed interact directly. We identify the exposed surface of FtsA helix 7, which also participates in binding to ATP through its internal surface, as a key interface needed for the interaction with ZipA. This interaction suggests that FtsZ's membrane tethers may regulate each other's activities.IMPORTANCE To divide, most bacteria first construct a protein machine at the plane of division and then recruit the machinery that will synthesize the division septum. In Escherichia coli, this first stage involves the assembly of FtsZ polymers at midcell, which directly bind to membrane-associated proteins FtsA and ZipA to form a discontinuous ring structure. Although FtsZ directly binds both FtsA and ZipA, it is unclear why FtsZ requires two separate membrane tethers. Here, we uncover a new direct interaction between the tethers, which involves a helix within FtsA that is adjacent to its ATP binding pocket. Our findings imply that in addition to their known roles as FtsZ membrane anchors, FtsA and ZipA may regulate each other's structure and function.
Collapse
|
16
|
Engholm DH, Kilian M, Goodsell DS, Andersen ES, Kjærgaard RS. A visual review of the human pathogen Streptococcus pneumoniae. FEMS Microbiol Rev 2018; 41:854-879. [PMID: 29029129 DOI: 10.1093/femsre/fux037] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 09/04/2017] [Indexed: 11/12/2022] Open
Abstract
Being the principal causative agent of bacterial pneumonia, otitis media, meningitis and septicemia, the bacterium Streptococcus pneumoniae is a major global health problem. To highlight the molecular basis of this problem, we have portrayed essential biological processes of the pneumococcal life cycle in eight watercolor paintings. The paintings are done to a consistent nanometer scale based on currently available data from structural biology and proteomics. In this review article, the paintings are used to provide a visual review of protein synthesis, carbohydrate metabolism, cell wall synthesis, cell division, teichoic acid synthesis, virulence, transformation and pilus synthesis based on the available scientific literature within the field of pneumococcal biology. Visualization of the molecular details of these processes reveals several scientific questions about how molecular components of the pneumococcal cell are organized to allow biological function to take place. By the presentation of this visual review, we intend to stimulate scientific discussion, aid in the generation of scientific hypotheses and increase public awareness. A narrated video describing the biological processes in the context of a whole-cell illustration accompany this article.
Collapse
Affiliation(s)
- Ditte Høyer Engholm
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Mogens Kilian
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - David S Goodsell
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.,Rutgers, the State University of New Jersey, NJ 08901, USA
| | - Ebbe Sloth Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark.,Interdisciplinary Nanoscience Center, Aarhus University, 8000 Aarhus, Denmark
| | | |
Collapse
|
17
|
Misra HS, Maurya GK, Chaudhary R, Misra CS. Interdependence of bacterial cell division and genome segregation and its potential in drug development. Microbiol Res 2018; 208:12-24. [DOI: 10.1016/j.micres.2017.12.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 12/05/2017] [Accepted: 12/31/2017] [Indexed: 11/28/2022]
|
18
|
Krupka M, Margolin W. Unite to divide: Oligomerization of tubulin and actin homologs regulates initiation of bacterial cell division. F1000Res 2018; 7:235. [PMID: 29560258 PMCID: PMC5832921 DOI: 10.12688/f1000research.13504.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/21/2018] [Indexed: 01/05/2023] Open
Abstract
To generate two cells from one, bacteria such as
Escherichia coli use a complex of membrane-embedded proteins called the divisome that synthesize the division septum. The initial stage of cytokinesis requires a tubulin homolog, FtsZ, which forms polymers that treadmill around the cell circumference. The attachment of these polymers to the cytoplasmic membrane requires an actin homolog, FtsA, which also forms dynamic polymers that directly bind to FtsZ. Recent evidence indicates that FtsA and FtsZ regulate each other’s oligomeric state in
E. coli to control the progression of cytokinesis, including the recruitment of septum synthesis proteins. In this review, we focus on recent advances in our understanding of protein-protein association between FtsZ and FtsA in the initial stages of divisome function, mainly in the well-characterized
E. coli system.
Collapse
Affiliation(s)
- Marcin Krupka
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, USA
| |
Collapse
|
19
|
Conti J, Viola MG, Camberg JL. FtsA reshapes membrane architecture and remodels the Z-ring in Escherichia coli. Mol Microbiol 2018; 107:558-576. [PMID: 29280220 DOI: 10.1111/mmi.13902] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 12/14/2017] [Accepted: 12/17/2017] [Indexed: 12/20/2022]
Abstract
Cell division in prokaryotes initiates with assembly of the Z-ring at midcell, which, in Escherichia coli, is tethered to the inner leaflet of the cytoplasmic membrane through a direct interaction with FtsA, a widely conserved actin homolog. The Z-ring is comprised of polymers of tubulin-like FtsZ and has been suggested to provide the force for constriction. Here, we demonstrate that FtsA exerts force on membranes causing redistribution of membrane architecture, robustly hydrolyzes ATP and directly engages FtsZ polymers in a reconstituted system. Phospholipid reorganization by FtsA occurs rapidly and is mediated by insertion of a C-terminal membrane targeting sequence (MTS) into the bilayer and further promoted by a nucleotide-dependent conformational change relayed to the MTS. FtsA also recruits FtsZ to phospholipid vesicles via a direct interaction with the FtsZ C-terminus and regulates FtsZ assembly kinetics. These results implicate the actin homolog FtsA in establishment of a Z-ring scaffold, while directly remodeling the membrane and provide mechanistic insight into localized cell wall remodeling, invagination and constriction at the onset of division.
Collapse
Affiliation(s)
| | | | - Jodi L Camberg
- Departments of Cell and Molecular Biology.,Nutrition and Food Sciences, The University of Rhode Island, Kingston, RI 02881, USA
| |
Collapse
|
20
|
Zheng JJ, Perez AJ, Tsui HCT, Massidda O, Winkler ME. Absence of the KhpA and KhpB (JAG/EloR) RNA-binding proteins suppresses the requirement for PBP2b by overproduction of FtsA in Streptococcus pneumoniae D39. Mol Microbiol 2017; 106:793-814. [PMID: 28941257 DOI: 10.1111/mmi.13847] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2017] [Indexed: 12/11/2022]
Abstract
Suppressor mutations were isolated that obviate the requirement for essential PBP2b in peripheral elongation of peptidoglycan from the midcells of dividing Streptococcus pneumoniae D39 background cells. One suppressor was in a gene encoding a single KH-domain protein (KhpA). ΔkhpA suppresses deletions in most, but not all (mltG), genes involved in peripheral PG synthesis and in the gpsB regulatory gene. ΔkhpA mutations reduce growth rate, decrease cell size, minimally affect shape and induce expression of the WalRK cell-wall stress regulon. Reciprocal co-immunoprecipitations show that KhpA forms a complex in cells with another KH-domain protein (KhpB/JAG/EloR). ΔkhpA and ΔkhpB mutants phenocopy each other exactly, consistent with a direct interaction. RNA-immunoprecipitation showed that KhpA/KhpB bind an overlapping set of RNAs in cells. Phosphorylation of KhpB reported previously does not affect KhpB function in the D39 progenitor background. A chromosome duplication implicated FtsA overproduction in Δpbp2b suppression. We show that cellular FtsA concentration is negatively regulated by KhpA/B at the post-transcriptional level and that FtsA overproduction is necessary and sufficient for suppression of Δpbp2b. However, increased FtsA only partially accounts for the phenotypes of ΔkhpA mutants. Together, these results suggest that multimeric KhpA/B may function as a pleiotropic RNA chaperone controlling pneumococcal cell division.
Collapse
Affiliation(s)
- Jiaqi J Zheng
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| | - Amilcar J Perez
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| | - Ho-Ching Tiffany Tsui
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| | - Orietta Massidda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, 09100 Cagliari, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington (IUB), Bloomington, IN 47405, USA
| |
Collapse
|
21
|
Krupka M, Rowlett VW, Morado D, Vitrac H, Schoenemann K, Liu J, Margolin W. Escherichia coli FtsA forms lipid-bound minirings that antagonize lateral interactions between FtsZ protofilaments. Nat Commun 2017; 8:15957. [PMID: 28695917 PMCID: PMC5508204 DOI: 10.1038/ncomms15957] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/15/2017] [Indexed: 01/19/2023] Open
Abstract
Most bacteria divide using a protein machine called the divisome that spans the cytoplasmic membrane. Key divisome proteins on the membrane’s cytoplasmic side include tubulin-like FtsZ, which forms GTP-dependent protofilaments, and actin-like FtsA, which tethers FtsZ to the membrane. Here we present genetic evidence that in Escherichia coli, FtsA antagonizes FtsZ protofilament bundling in vivo. We then show that purified FtsA does not form straight polymers on lipid monolayers as expected, but instead assembles into dodecameric minirings, often in hexameric arrays. When coassembled with FtsZ on lipid monolayers, these FtsA minirings appear to guide FtsZ to form long, often parallel, but unbundled protofilaments, whereas a mutant of FtsZ (FtsZ*) with stronger lateral interactions remains bundled. In contrast, a hypermorphic mutant of FtsA (FtsA*) forms mainly arcs instead of minirings and enhances lateral interactions between FtsZ protofilaments. Based on these results, we propose that FtsA antagonizes lateral interactions between FtsZ protofilaments, and that the oligomeric state of FtsA may influence FtsZ higher-order structure and divisome function. The actin-like protein FtsA and the tubulin-like protein FtsZ play crucial roles during cell division in most bacteria. Here, the authors show that FtsA forms minirings on lipid monolayers, and present evidence supporting that its oligomeric state modulates the bundling of FtsZ protofilaments.
Collapse
Affiliation(s)
- Marcin Krupka
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| | - Veronica W Rowlett
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| | - Dustin Morado
- Department of Pathology and Laboratory Medicine, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| | - Heidi Vitrac
- Department of Biochemistry and Molecular Biology, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| | - Kara Schoenemann
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| | - Jun Liu
- Department of Pathology and Laboratory Medicine, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| |
Collapse
|
22
|
Abstract
The last three decades have witnessed an explosion of discoveries about the mechanistic details of binary fission in model bacteria such as Escherichia coli, Bacillus subtilis, and Caulobacter crescentus. This was made possible not only by advances in microscopy that helped answer questions about cell biology but also by clever genetic manipulations that directly and easily tested specific hypotheses. More recently, research using understudied organisms, or nonmodel systems, has revealed several alternate mechanistic strategies that bacteria use to divide and propagate. In this review, we highlight new findings and compare these strategies to cell division mechanisms elucidated in model organisms.
Collapse
Affiliation(s)
- Prahathees J Eswara
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida 33620;
| | - Kumaran S Ramamurthi
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-5132;
| |
Collapse
|
23
|
Zou Y, Li Y, Ekanayake SB, Dillon JAR. An Escherichia coli expression model reveals the species-specific function of FtsA from Neisseria gonorrhoeae in cell division. FEMS Microbiol Lett 2017; 364:3739240. [PMID: 28431102 DOI: 10.1093/femsle/fnx078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/17/2017] [Indexed: 11/14/2022] Open
Abstract
Escherichia coli (Ec) has been used to study the function of cell division proteins from different microorganisms, especially when genetic tools are limited for studying these proteins in their native hosts. The expression of ftsA from Neisseria gonorrhoeae (Ng) disrupted cell division in E. coli resulting in a significant increase in cell length. In some cells, FtsANg localised to the division site and the poles of E. coli cells, but the majority of cells showed no specifical localisation. FtsANg did not complement an E. coli ftsA mutant strain. Bacterial two-hybrid and GST pull-down assays indicated that FtsANg interacted with FtsNEc, but no other cell division proteins from E. coli. This interaction was mediated through the 2A and 2B subdomains of FtsANg. This evidence suggests that the function of FtsANg is species specific.
Collapse
Affiliation(s)
- Yinan Zou
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan, SK S7N 5E5, Canada.,Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, SK S7N 5E5, Canada
| | - Yan Li
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, SK S7N 5E5, Canada.,Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Sanjaya B Ekanayake
- Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, SK S7N 5E5, Canada
| | - Jo-Anne R Dillon
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan, SK S7N 5E5, Canada.,Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, SK S7N 5E5, Canada.,Department of Biology, College of Arts and Science, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| |
Collapse
|
24
|
Rued BE, Zheng JJ, Mura A, Tsui HCT, Boersma MJ, Mazny JL, Corona F, Perez AJ, Fadda D, Doubravová L, Buriánková K, Branny P, Massidda O, Winkler ME. Suppression and synthetic-lethal genetic relationships of ΔgpsB mutations indicate that GpsB mediates protein phosphorylation and penicillin-binding protein interactions in Streptococcus pneumoniae D39. Mol Microbiol 2017; 103:931-957. [PMID: 28010038 DOI: 10.1111/mmi.13613] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2016] [Indexed: 01/06/2023]
Abstract
GpsB regulatory protein and StkP protein kinase have been proposed as molecular switches that balance septal and peripheral (side-wall like) peptidoglycan (PG) synthesis in Streptococcus pneumoniae (pneumococcus); yet, mechanisms of this switching remain unknown. We report that ΔdivIVA mutations are not epistatic to ΔgpsB division-protein mutations in progenitor D39 and related genetic backgrounds; nor is GpsB required for StkP localization or FDAA labeling at septal division rings. However, we confirm that reduction of GpsB amount leads to decreased protein phosphorylation by StkP and report that the essentiality of ΔgpsB mutations is suppressed by inactivation of PhpP protein phosphatase, which concomitantly restores protein phosphorylation levels. ΔgpsB mutations are also suppressed by other classes of mutations, including one that eliminates protein phosphorylation and may alter division. Moreover, ΔgpsB mutations are synthetically lethal with Δpbp1a, but not Δpbp2a or Δpbp1b mutations, suggesting GpsB activation of PBP2a activity. Consistent with this result, co-IP experiments showed that GpsB complexes with EzrA, StkP, PBP2a, PBP2b and MreC in pneumococcal cells. Furthermore, depletion of GpsB prevents PBP2x migration to septal centers. These results support a model in which GpsB negatively regulates peripheral PG synthesis by PBP2b and positively regulates septal ring closure through its interactions with StkP-PBP2x.
Collapse
Affiliation(s)
- Britta E Rued
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Jiaqi J Zheng
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Andrea Mura
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy.,Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Ho-Ching T Tsui
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Michael J Boersma
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Jeffrey L Mazny
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Federico Corona
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
| | - Amilcar J Perez
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| | - Daniela Fadda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
| | - Linda Doubravová
- Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Karolína Buriánková
- Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Pavel Branny
- Cell and Molecular Microbiology Division, Institute of Microbiology, v.v.i, Academy of Sciences of the Czech Republic, Prague 4, 142 20, Czech Republic
| | - Orietta Massidda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN 47405, USA
| |
Collapse
|
25
|
Roles of the Essential Protein FtsA in Cell Growth and Division in Streptococcus pneumoniae. J Bacteriol 2017; 199:JB.00608-16. [PMID: 27872183 DOI: 10.1128/jb.00608-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/16/2016] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is an ovoid-shaped Gram-positive bacterium that grows by carrying out peripheral and septal peptidoglycan (PG) synthesis, analogous to model bacilli, such as Escherichia coli and Bacillus subtilis In the model bacilli, FtsZ and FtsA proteins assemble into a ring at midcell and are dedicated to septal PG synthesis but not peripheral PG synthesis; hence, inactivation of FtsZ or FtsA results in long filamentous cells unable to divide. Here, we demonstrate that FtsA and FtsZ colocalize at midcell in S. pneumoniae and that partial depletion of FtsA perturbs septum synthesis, resulting in elongated cells with multiple FtsZ rings that fail to complete septation. Unexpectedly, complete depletion of FtsA resulted in the delocalization of FtsZ rings and ultimately cell ballooning and lysis. In contrast, depletion or deletion of gpsB and sepF, which in B. subtilis are synthetically lethal with ftsA, resulted in enlarged and elongated cells with multiple FtsZ rings, with deletion of sepF mimicking partial depletion of FtsA. Notably, cell ballooning was not observed, consistent with later recruitment of these proteins to midcell after Z-ring assembly. The overproduction of FtsA stimulates septation and suppresses the cell division defects caused by the deletion of sepF and gpsB under some conditions, supporting the notion that FtsA shares overlapping functions with GpsB and SepF at later steps in the division process. Our results indicate that, in S. pneumoniae, both GpsB and SepF are involved in septal PG synthesis, whereas FtsA and FtsZ coordinate both peripheral and septal PG synthesis and are codependent for localization at midcell.IMPORTANCEStreptococcus pneumoniae (pneumococcus) is a clinically important human pathogen for which more therapies against unexploited essential targets, like cell growth and division proteins, are needed. Pneumococcus is an ovoid-shaped Gram-positive bacterium with cell growth and division properties that have important distinctions from those of rod-shaped bacteria. Gaining insights into these processes can thus provide valuable information to develop novel antimicrobials. Whereas rods use distinctly localized protein machines at different cellular locations to synthesize peripheral and septal peptidoglycans, we present evidence that S. pneumoniae organizes these two machines at a single location in the middle of dividing cells. Here, we focus on the properties of the actin-like protein FtsA as an essential orchestrator of peripheral and septal growth in this bacterium.
Collapse
|
26
|
Loose M, Zieske K, Schwille P. Reconstitution of Protein Dynamics Involved in Bacterial Cell Division. Subcell Biochem 2017; 84:419-444. [PMID: 28500535 DOI: 10.1007/978-3-319-53047-5_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Even simple cells like bacteria have precisely regulated cellular anatomies, which allow them to grow, divide and to respond to internal or external cues with high fidelity. How spatial and temporal intracellular organization in prokaryotic cells is achieved and maintained on the basis of locally interacting proteins still remains largely a mystery. Bulk biochemical assays with purified components and in vivo experiments help us to approach key cellular processes from two opposite ends, in terms of minimal and maximal complexity. However, to understand how cellular phenomena emerge, that are more than the sum of their parts, we have to assemble cellular subsystems step by step from the bottom up. Here, we review recent in vitro reconstitution experiments with proteins of the bacterial cell division machinery and illustrate how they help to shed light on fundamental cellular mechanisms that constitute spatiotemporal order and regulate cell division.
Collapse
Affiliation(s)
- Martin Loose
- Institute for Science and Technology Austria (IST Austria), Klosterneuburg, Austria.
| | | | | |
Collapse
|
27
|
Abstract
A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.
Collapse
Affiliation(s)
- Thierry Izoré
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Fusinita van den Ent
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK.
| |
Collapse
|
28
|
Abstract
In bacteria and archaea, the most widespread cell division system is based on the tubulin homologue FtsZ protein, whose filaments form the cytokinetic Z-ring. FtsZ filaments are tethered to the membrane by anchors such as FtsA and SepF and are regulated by accessory proteins. One such set of proteins is responsible for Z-ring's spatiotemporal regulation, essential for the production of two equal-sized daughter cells. Here, we describe how our still partial understanding of the FtsZ-based cell division process has been progressed by visualising near-atomic structures of Z-rings and complexes that control Z-ring positioning in cells, most notably the MinCDE and Noc systems that act by negatively regulating FtsZ filaments. We summarise available data and how they inform mechanistic models for the cell division process.
Collapse
|
29
|
Abstract
Cytokinesis in E. coli is organized by a cytoskeletal element designated the Z ring. The Z ring is formed at midcell by the coalescence of FtsZ filaments tethered to the membrane by interaction of FtsZ's conserved C-terminal peptide (CCTP) with two membrane-associated proteins, FtsA and ZipA. Although interaction between an FtsZ monomer and either of these proteins is of low affinity, high affinity is achieved through avidity - polymerization linked CCTPs interacting with the membrane tethers. The placement of the Z ring at midcell is ensured by antagonists of FtsZ polymerization that are positioned within the cell and target FtsZ filaments through the CCTP. The placement of the ring is reinforced by a protein network that extends from the terminus (Ter) region of the chromosome to the Z ring. Once the Z ring is established, additional proteins are recruited through interaction with FtsA, to form the divisome. The assembled divisome is then activated by FtsN to carry out septal peptidoglycan synthesis, with a dynamic Z ring serving as a guide for septum formation. As the septum forms, the cell wall is split by spatially regulated hydrolases and the outer membrane invaginates in step with the aid of a transenvelope complex to yield progeny cells.
Collapse
Affiliation(s)
- Joe Lutkenhaus
- University of Kansas Medical Center, Kansas City, KS, USA.
| | - Shishen Du
- University of Kansas Medical Center, Kansas City, KS, USA
| |
Collapse
|
30
|
Busiek KK, Margolin W. Bacterial actin and tubulin homologs in cell growth and division. Curr Biol 2016; 25:R243-R254. [PMID: 25784047 DOI: 10.1016/j.cub.2015.01.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In contrast to the elaborate cytoskeletal machines harbored by eukaryotic cells, such as mitotic spindles, cytoskeletal structures detectable by typical negative stain electron microscopy are generally absent from bacterial cells. As a result, for decades it was thought that bacteria lacked cytoskeletal machines. Revolutions in genomics and fluorescence microscopy have confirmed the existence not only of smaller-scale cytoskeletal structures in bacteria, but also of widespread functional homologs of eukaryotic cytoskeletal proteins. The presence of actin, tubulin, and intermediate filament homologs in these relatively simple cells suggests that primitive cytoskeletons first arose in bacteria. In bacteria such as Escherichia coli, homologs of tubulin and actin directly interact with each other and are crucial for coordinating cell growth and division. The function and direct interactions between these proteins will be the focus of this review.
Collapse
Affiliation(s)
- Kimberly K Busiek
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX 77030, USA.
| |
Collapse
|
31
|
Haeusser DP, Margolin W. Splitsville: structural and functional insights into the dynamic bacterial Z ring. Nat Rev Microbiol 2016; 14:305-19. [PMID: 27040757 DOI: 10.1038/nrmicro.2016.26] [Citation(s) in RCA: 216] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Bacteria must divide to increase in number and colonize their niche. Binary fission is the most widespread means of bacterial cell division, but even this relatively simple mechanism has many variations on a theme. In most bacteria, the tubulin homologue FtsZ assembles into a ring structure, termed the Z ring, at the site of cytokinesis and recruits additional proteins to form a large protein machine - the divisome - that spans the membrane. In this Review, we discuss current insights into the regulation of the assembly of the Z ring and how the divisome drives membrane invagination and septal cell wall growth while flexibly responding to various cellular inputs.
Collapse
Affiliation(s)
- Daniel P Haeusser
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA.,Biology Department, Canisius College, 2001 Main Street, Buffalo, New York 14208, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
| |
Collapse
|
32
|
|
33
|
Ortiz C, Natale P, Cueto L, Vicente M. The keepers of the ring: regulators of FtsZ assembly. FEMS Microbiol Rev 2015; 40:57-67. [PMID: 26377318 DOI: 10.1093/femsre/fuv040] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2015] [Indexed: 11/13/2022] Open
Abstract
FtsZ, a GTPase distributed in the cytoplasm of most bacteria, is the major component of the machinery responsible for division (the divisome) in Escherichia coli. It interacts with additional proteins that contribute to its function forming a ring at the midcell that is essential to constrict the membrane. FtsZ is indirectly anchored to the membrane and it is prevented from polymerizing at locations where septation is undesired. Several properties of FtsZ are mediated by other proteins that function as keepers of the ring. ZipA and FtsA serve to anchor the ring, and together with a set of Zap proteins, they stabilize it. The MinCDE and SlmA proteins prevent the polymerization of FtsZ at sites other than the midcell. Finally, ClpP degrades FtsZ, an action prevented by ZipA. Many of the FtsZ keepers interact with FtsZ through a central hub located at its carboxy terminal end.
Collapse
Affiliation(s)
- Cristina Ortiz
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC), C/ Darwin 3, Madrid 28049, Spain
| | - Paolo Natale
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC), C/ Darwin 3, Madrid 28049, Spain
| | - Laura Cueto
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC), C/ Darwin 3, Madrid 28049, Spain
| | - Miguel Vicente
- Centro Nacional de Biotecnología - Consejo Superior de Investigaciones Científicas (CNB-CSIC), C/ Darwin 3, Madrid 28049, Spain
| |
Collapse
|
34
|
Salvarelli E, Krupka M, Rivas G, Mingorance J, Gómez-Puertas P, Alfonso C, Rico AI. The Cell Division Protein FtsZ from Streptococcus pneumoniae Exhibits a GTPase Activity Delay. J Biol Chem 2015; 290:25081-9. [PMID: 26330552 DOI: 10.1074/jbc.m115.650077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Indexed: 11/06/2022] Open
Abstract
The cell division protein FtsZ assembles in vitro by a mechanism of cooperative association dependent on GTP, monovalent cations, and Mg(2+). We have analyzed the GTPase activity and assembly dynamics of Streptococcus pneumoniae FtsZ (SpnFtsZ). SpnFtsZ assembled in an apparently cooperative process, with a higher critical concentration than values reported for other FtsZ proteins. It sedimented in the presence of GTP as a high molecular mass polymer with a well defined size and tended to form double-stranded filaments in electron microscope preparations. GTPase activity depended on K(+) and Mg(2+) and was inhibited by Na(+). GTP hydrolysis exhibited a delay that included a lag phase followed by a GTP hydrolysis activation step, until reaction reached the GTPase rate. The lag phase was not found in polymer assembly, suggesting a transition from an initial non-GTP-hydrolyzing polymer that switches to a GTP-hydrolyzing polymer, supporting models that explain FtsZ polymer cooperativity.
Collapse
Affiliation(s)
- Estefanía Salvarelli
- From the Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid, Spain, Biomol-Informatics S.L., Universidad Autónoma, 28049 Madrid, Spain,
| | | | - Germán Rivas
- the Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain
| | - Jesus Mingorance
- From the Servicio de Microbiología, Hospital Universitario La Paz, IdiPAZ, 28046 Madrid, Spain
| | - Paulino Gómez-Puertas
- Biomol-Informatics S.L., Universidad Autónoma, 28049 Madrid, Spain, the Molecular Modelling Group, Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain, and
| | - Carlos Alfonso
- the Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28040 Madrid, Spain
| | | |
Collapse
|
35
|
Remodeling of the Z-Ring Nanostructure during the Streptococcus pneumoniae Cell Cycle Revealed by Photoactivated Localization Microscopy. mBio 2015; 6:mBio.01108-15. [PMID: 26286692 PMCID: PMC4542196 DOI: 10.1128/mbio.01108-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ovococci form a morphological group that includes several human pathogens (enterococci and streptococci). Their shape results from two modes of cell wall insertion, one allowing division and one allowing elongation. Both cell wall synthesis modes rely on a single cytoskeletal protein, FtsZ. Despite the central role of FtsZ in ovococci, a detailed view of the in vivo nanostructure of ovococcal Z-rings has been lacking thus far, limiting our understanding of their assembly and architecture. We have developed the use of photoactivated localization microscopy (PALM) in the ovococcus human pathogen Streptococcus pneumoniae by engineering spDendra2, a photoconvertible fluorescent protein optimized for this bacterium. Labeling of endogenously expressed FtsZ with spDendra2 revealed the remodeling of the Z-ring’s morphology during the division cycle at the nanoscale level. We show that changes in the ring’s axial thickness and in the clustering propensity of FtsZ correlate with the advancement of the cell cycle. In addition, we observe double-ring substructures suggestive of short-lived intermediates that may form upon initiation of septal cell wall synthesis. These data are integrated into a model describing the architecture and the remodeling of the Z-ring during the cell cycle of ovococci. The Gram-positive human pathogen S. pneumoniae is responsible for 1.6 million deaths per year worldwide and is increasingly resistant to various antibiotics. FtsZ is a cytoskeletal protein polymerizing at midcell into a ring-like structure called the Z-ring. FtsZ is a promising new antimicrobial target, as its inhibition leads to cell death. A precise view of the Z-ring architecture in vivo is essential to understand the mode of action of inhibitory drugs (see T. den Blaauwen, J. M. Andreu, and O. Monasterio, Bioorg Chem 55:27–38, 2014, doi:10.1016/j.bioorg.2014.03.007, for a review on FtsZ inhibitors). This is notably true in ovococcoid bacteria like S. pneumoniae, in which FtsZ is the only known cytoskeletal protein. We have used superresolution microscopy to obtain molecular details of the pneumococcus Z-ring that have so far been inaccessible with conventional microscopy. This study provides a nanoscale description of the Z-ring architecture and remodeling during the division of ovococci.
Collapse
|
36
|
Abstract
It is now well established that prokaryotic cells assemble diverse proteins into dynamic cytoskeletal filaments that perform essential cellular functions. Although most of the filaments assemble on their own to form higher order structures, growing evidence suggests that there are a number of prokaryotic proteins that polymerise only in the presence of a matrix such as DNA, lipid membrane or even another filament. Matrix-assisted filament systems are frequently nucleotide dependent and cytomotive but rarely considered as part of the bacterial cytoskeleton. Here, we categorise this family of filament-forming systems as collaborative filaments and introduce a simple nomenclature. Collaborative filaments are frequent in both eukaryotes and prokaryotes and are involved in vital cellular processes including chromosome segregation, DNA repair and maintenance, gene silencing and cytokinesis to mention a few. In this review, we highlight common principles underlying collaborative filaments and correlate these with known functions.
Collapse
Affiliation(s)
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Cambridge, UK
| |
Collapse
|
37
|
Terrasse R, Amoroso A, Vernet T, Di Guilmi AM. Streptococcus pneumoniae GAPDH Is Released by Cell Lysis and Interacts with Peptidoglycan. PLoS One 2015; 10:e0125377. [PMID: 25927608 PMCID: PMC4415926 DOI: 10.1371/journal.pone.0125377] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/23/2015] [Indexed: 11/26/2022] Open
Abstract
Release of conserved cytoplasmic proteins is widely spread among Gram-positive and Gram-negative bacteria. Because these proteins display additional functions when located at the bacterial surface, they have been qualified as moonlighting proteins. The GAPDH is a glycolytic enzyme which plays an important role in the virulence processes of pathogenic microorganisms like bacterial invasion and host immune system modulation. However, GAPDH, like other moonlighting proteins, cannot be secreted through active secretion systems since they do not contain an N-terminal predicted signal peptide. In this work, we investigated the mechanism of GAPDH export and surface retention in Streptococcus pneumoniae, a major human pathogen. We addressed the role of the major autolysin LytA in the delivery process of GAPDH to the cell surface. Pneumococcal lysis is abolished in the ΔlytA mutant strain or when 1% choline chloride is added in the culture media. We showed that these conditions induce a marked reduction in the amount of surface-associated GAPDH. These data suggest that the presence of GAPDH at the surface of pneumococcal cells depends on the LytA-mediated lysis of a fraction of the cell population. Moreover, we demonstrated that pneumococcal GAPDH binds to the bacterial cell wall independently of the presence of the teichoic acids component, supporting peptidoglycan as a ligand to surface GAPDH. Finally, we showed that peptidoglycan-associated GAPDH recruits C1q from human serum but does not activate the complement pathway.
Collapse
Affiliation(s)
- Rémi Terrasse
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 71 Avenue des Martyrs, F-38044 Grenoble, France
- CNRS UMR5075, IBS, F-38044 Grenoble, France
- CEA, DSV, IBS, F-38044 Grenoble, France
| | - Ana Amoroso
- Centre for Protein Engineering, Department of Life Sciences, University of Liege, Liege, Belgium
| | - Thierry Vernet
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 71 Avenue des Martyrs, F-38044 Grenoble, France
- CNRS UMR5075, IBS, F-38044 Grenoble, France
- CEA, DSV, IBS, F-38044 Grenoble, France
| | - Anne Marie Di Guilmi
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 71 Avenue des Martyrs, F-38044 Grenoble, France
- CNRS UMR5075, IBS, F-38044 Grenoble, France
- CEA, DSV, IBS, F-38044 Grenoble, France
- * E-mail:
| |
Collapse
|
38
|
Liu B, Persons L, Lee L, de Boer PAJ. Roles for both FtsA and the FtsBLQ subcomplex in FtsN-stimulated cell constriction in Escherichia coli. Mol Microbiol 2015; 95:945-70. [PMID: 25496160 DOI: 10.1111/mmi.12906] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2014] [Indexed: 12/18/2022]
Abstract
Escherichia coli FtsN is a bitopic membrane protein that is essential for triggering active cell constriction. A small periplasmic subdomain ((E) FtsN) is required and sufficient for function, but its mechanism of action is unclear. We isolated extragenic (E) FtsN*-suppressing mutations that restore division in cells producing otherwise non-functional variants of FtsN. These mapped to the IC domain of FtsA in the cytoplasm and to small subdomains of the FtsB and FtsL proteins in the periplasm. All FtsB and FtsL variants allowed survival without (E) FtsN, but many then imposed a new requirement for interaction between the cytoplasmic domain of FtsN ((N) FtsN) and FtsA. Alternatively, variants of FtsA, FtsB or FtsL acted synergistically to allow cell division in the complete absence of FtsN. Strikingly, moreover, substitution of a single residue in FtsB (E56) proved sufficient to rescue ΔftsN cells as well. In FtsN(+) cells, (E) FtsN*-suppressing mutations promoted cell fission at an abnormally small cell size, and caused cell shape and integrity defects under certain conditions. This and additional evidence support a model in which FtsN acts on either side of the membrane to induce a conformational switch in both FtsA and the FtsBLQ subcomplex to de-repress septal peptidoglycan synthesis and membrane invagination.
Collapse
Affiliation(s)
- Bing Liu
- Department of Molecular Biology & Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106-4960, USA
| | | | | | | |
Collapse
|
39
|
Broughton CE, Roper DI, Van Den Berg HA, Rodger A. Bacterial cell division: experimental and theoretical approaches to the divisome. Sci Prog 2015; 98:313-45. [PMID: 26790174 PMCID: PMC10365498 DOI: 10.3184/003685015x14461391862881] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cell division is a key event in the bacterial life cycle. It involves constriction at the midcell, so that one cell can give rise to two daughter cells. This constriction is mediated by a ring composed offibrous multimers of the protein FtsZ. However a host of additional factors is involved in the formation and dynamics of this "Z-ring" and this complicated apparatus is collectively known as the "divisome". We review the literature, with an emphasis on mathematical modelling, and show how such theoretical efforts have helped experimentalists to make sense of the at times bewildering data, and plan further experiments.
Collapse
|
40
|
Modi K, Misra HS. Dr-FtsA, an actin homologue in Deinococcus radiodurans differentially affects Dr-FtsZ and Ec-FtsZ functions in vitro. PLoS One 2014; 9:e115918. [PMID: 25551229 PMCID: PMC4281207 DOI: 10.1371/journal.pone.0115918] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/29/2014] [Indexed: 11/24/2022] Open
Abstract
The Deinococcus radiodurans genome encodes homologues of divisome proteins including FtsZ and FtsA. FtsZ of this bacterium (Dr-FtsZ) has been recently characterized. In this paper, we study FtsA of D. radiodurans (Dr-FtsA) and its involvement in regulation of FtsZ function. Recombinant Dr-FtsA showed neither ATPase nor GTPase activity and its polymerization was ATP dependent. Interestingly, we observed that Dr-FtsA, when compared with E. coli FtsA (Ec-FtsA), has lower affinity for both Dr-FtsZ and Ec-FtsZ. Also, Dr-FtsA showed differential effects on GTPase activity and sedimentation characteristics of Dr-FtsZ and Ec-FtsZ. For instance, Dr-FtsA stimulated GTPase activity of Dr-FtsZ while GTPase activity of Ec-FtsZ was reduced in the presence of Dr-FtsA. Stimulation of GTPase activity of Dr-FtsZ by Dr-FtsA resulted in depolymerization of Dr-FtsZ. Dr-FtsA effects on GTPase activity and polymerization/depolymerisation characteristics of Dr-FtsZ did not change significantly in the presence of ATP. Recombinant E. coli expressing Dr-FtsA showed cell division inhibition in spite of in trans expression of Dr-FtsZ in these cells. These results suggested that Dr-FtsA, although it lacks ATPase activity, is still functional and differentially affects Dr-FtsZ and Ec-FtsZ function in vitro.
Collapse
Affiliation(s)
- Kruti Modi
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India
| | - Hari S. Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, 400 085, India
- * E-mail:
| |
Collapse
|
41
|
LocZ is a new cell division protein involved in proper septum placement in Streptococcus pneumoniae. mBio 2014; 6:e01700-14. [PMID: 25550321 PMCID: PMC4281919 DOI: 10.1128/mbio.01700-14] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED How bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement in Streptococcus pneumoniae. We show that locZ is not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division. IMPORTANCE Bacterial cell division is a highly ordered process regulated in time and space. Recently, we reported that the Ser/Thr protein kinase StkP regulates cell division in Streptococcus pneumoniae, through phosphorylation of several key proteins. Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ. We show that LocZ is a new cell division protein important for proper septum placement and likely functions as a marker of the cell division site. Consistently, LocZ supports proper Z-ring positioning at midcell. LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.
Collapse
|
42
|
Szwedziak P, Wang Q, Bharat TAM, Tsim M, Löwe J. Architecture of the ring formed by the tubulin homologue FtsZ in bacterial cell division. eLife 2014; 3:e04601. [PMID: 25490152 PMCID: PMC4383033 DOI: 10.7554/elife.04601] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/08/2014] [Indexed: 12/16/2022] Open
Abstract
Membrane constriction is a prerequisite for cell division. The most common membrane
constriction system in prokaryotes is based on the tubulin homologue FtsZ, whose
filaments in E. coli are anchored to the membrane by FtsA and enable
the formation of the Z-ring and divisome. The precise architecture of the FtsZ ring
has remained enigmatic. In this study, we report three-dimensional arrangements of
FtsZ and FtsA filaments in C. crescentus and E.
coli cells and inside constricting liposomes by means of electron
cryomicroscopy and cryotomography. In vivo and in vitro, the Z-ring is composed of a
small, single-layered band of filaments parallel to the membrane, creating a
continuous ring through lateral filament contacts. Visualisation of the in vitro
reconstituted constrictions as well as a complete tracing of the helical paths of the
filaments with a molecular model favour a mechanism of FtsZ-based membrane
constriction that is likely to be accompanied by filament sliding. DOI:http://dx.doi.org/10.7554/eLife.04601.001 Cell division is the process by which new cells are made. It is therefore vital for
the growth and development, and the regeneration and repair of damaged tissues. When
bacterial and animal cells divide, they must constrict their membrane inwards to
split a single cell into two. In most bacteria, this constriction is guided by a
ring-like structure that contains filaments of a protein called FtsZ. During cell
division, this structure forms around the inside edge of the cell and when it
contracts, it pulls the membrane inwards and causes the cell to constrict and
eventually divide. In recent years, this arrangement of FtsZ filaments has been intensively
investigated, giving rise to various theories about how it is made and how it works:
for example, some recent studies suggested that FtsZ does not form a continuous ring.
Nevertheless, many details about the cell division process remain unknown. Szwedziak, Wang et al. have now investigated this protein ring in two species of
bacteria by turning to advanced forms of microscopy to closely observe its structure
and how it works. This included mapping the ring in three dimensions. Contrary to
earlier reports that the FtsZ ring is discontinuous, in both a bacterium called
Caulobacter crescentus and another called Escherichia
coli, the ring forms a continuous shape made up of overlapping
filaments. Szwedziak, Wang et al. then increased the levels of two of the ring's main
components: the FtsZ protein that forms the filaments and a protein that anchors
these filaments to the cell membrane. This caused the modified cells to constrict and
divide at extra sites, which resulted in the formation of abnormally small cells.
These findings suggest that these two ring components by themselves are able to
generate both the structures and force required for cell constriction. This is
supported by the fact that when they were introduced into artificial cell-like
structures, these proteins spontaneously self-organised into rings and triggered
constriction where they formed. Szwedziak, Wang et al. propose that constriction only starts once the FtsZ protein
forms a closed ring and that the ring's overlapping filaments slide along each other
to further decrease its diameter and constrict the cell. The degree of filament
overlap likely also increases with constriction, requiring filaments to be shortened
to maintain sliding. This shortening, along with sliding, could provide a mechanism
by which to drive the constriction process. This work will be followed by even more detailed studies in order to understand the
process of bacterial cell division at the atomic scale and how the cell's wall is
reshaped during the process. In the long run, intricate knowledge of how a bacterial
cell divides might enable the design of new classes of antibiotics targeting the
molecular machinery involved. DOI:http://dx.doi.org/10.7554/eLife.04601.002
Collapse
Affiliation(s)
- Piotr Szwedziak
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Qing Wang
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Tanmay A M Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Matthew Tsim
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Jan Löwe
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| |
Collapse
|
43
|
Abstract
UNLABELLED Together with ATP, the C-terminal region of the essential streptococcal FtsA protein acts as an intramolecular switch to promote its polymerization and attachment to the membrane. During septation, FtsA is known to anchor the constricting FtsZ ring and, subsequently, the divisome to the membrane. Truncation of the C terminus of the streptococcal FtsA (FtsAΔCt) facilitates a more rapid ATP-dependent polymerization in solution than is seen with the full-length protein (FtsA(+)). The FtsAΔCt polymers are more organized and compact than those formed in solution by FtsA(+), resembling the shape of the membrane-associated FtsA(+) polymers. We find that ATP, besides being needed for polymerization, is required for the attachment of FtsA(+) to lipid monolayers and to vesicle membranes. We propose a model in which the binding of ATP activates a switch favoring the polymerization of FtsA and at the same time driving the amphipathic helix at its C terminus to become attached to the membrane. Conversely, when FtsA is in the cytoplasm, the C terminus is not engaged in the attachment to the membrane, and it obstructs polymerization. ATP-dependent polymerization of FtsA inside membrane vesicles causes vesicle shrinkage, suggesting that, besides providing a membrane attachment for FtsZ, the FtsA C terminus may also introduce local alterations in the membrane to facilitate septation. IMPORTANCE FtsA is a protein needed in many bacteria to construct a septum that divides one fully grown cell, producing two daughters. We show that the region located at the C-terminal end of the Streptococcus pneumoniae FtsA protein works as a switch triggered by ATP, a molecule that stores energy. This region contains an amphipathic helix that obstructs the assembly of FtsA into polymers in the cytoplasm. In the presence of ATP, the obstruction is removed by switching the position of the helix. The switch directs the helix to the membrane and simultaneously facilitates the polymerization of the protein. The accumulation of FtsA molecules at the membrane causes distortions, an effect produced also by proteins such as MinD, MreB, and SepF that also contain amphipathic helixes as membrane attachment devices. In the case of FtsA, these distortions may also facilitate the initial events that lead to the division of bacteria.
Collapse
|
44
|
Interplay between two bacterial actin homologs, MamK and MamK-Like, is required for the alignment of magnetosome organelles in Magnetospirillum magneticum AMB-1. J Bacteriol 2014; 196:3111-21. [PMID: 24957623 DOI: 10.1128/jb.01674-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Many bacterial species contain multiple actin-like proteins tasked with the execution of crucial cell biological functions. MamK, an actin-like protein found in magnetotactic bacteria, is important in organizing magnetosome organelles into chains that are used for navigation along geomagnetic fields. MamK and numerous other magnetosome formation factors are encoded by a genetic island termed the magnetosome island. Unlike most magnetotactic bacteria, Magnetospirillum magneticum AMB-1 (AMB-1) contains a second island of magnetosome-related genes that was named the magnetosome islet. A homologous copy of mamK, mamK-like, resides within this islet and encodes a protein capable of filament formation in vitro. Previous work had shown that mamK-like is expressed in vivo, but its function, if any, had remained unknown. Though MamK-like is highly similar to MamK, it contains a mutation that in MamK and other actins blocks ATPase activity in vitro and filament dynamics in vivo. Here, using genetic analysis, we demonstrate that mamK-like has an in vivo role in assisting organelle alignment. In addition, MamK-like forms filaments in vivo in a manner that is dependent on the presence of MamK and the two proteins interact in a yeast two-hybrid assay. Surprisingly, despite the ATPase active-site mutation, MamK-like is capable of ATP hydrolysis in vitro and promotes MamK filament turnover in vivo. Taken together, these experiments suggest that direct interactions between MamK and MamK-like contribute to magnetosome alignment in AMB-1.
Collapse
|
45
|
Crystal structure of FtsA fromStaphylococcus aureus. FEBS Lett 2014; 588:1879-85. [DOI: 10.1016/j.febslet.2014.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 04/02/2014] [Accepted: 04/02/2014] [Indexed: 11/22/2022]
|
46
|
Interplay of the serine/threonine-kinase StkP and the paralogs DivIVA and GpsB in pneumococcal cell elongation and division. PLoS Genet 2014; 10:e1004275. [PMID: 24722178 PMCID: PMC3983041 DOI: 10.1371/journal.pgen.1004275] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 02/16/2014] [Indexed: 01/17/2023] Open
Abstract
Despite years of intensive research, much remains to be discovered to understand the regulatory networks coordinating bacterial cell growth and division. The mechanisms by which Streptococcus pneumoniae achieves its characteristic ellipsoid-cell shape remain largely unknown. In this study, we analyzed the interplay of the cell division paralogs DivIVA and GpsB with the ser/thr kinase StkP. We observed that the deletion of divIVA hindered cell elongation and resulted in cell shortening and rounding. By contrast, the absence of GpsB resulted in hampered cell division and triggered cell elongation. Remarkably, ΔgpsB elongated cells exhibited a helical FtsZ pattern instead of a Z-ring, accompanied by helical patterns for DivIVA and peptidoglycan synthesis. Strikingly, divIVA deletion suppressed the elongated phenotype of ΔgpsB cells. These data suggest that DivIVA promotes cell elongation and that GpsB counteracts it. Analysis of protein-protein interactions revealed that GpsB and DivIVA do not interact with FtsZ but with the cell division protein EzrA, which itself interacts with FtsZ. In addition, GpsB interacts directly with DivIVA. These results are consistent with DivIVA and GpsB acting as a molecular switch to orchestrate peripheral and septal PG synthesis and connecting them with the Z-ring via EzrA. The cellular co-localization of the transpeptidases PBP2x and PBP2b as well as the lipid-flippases FtsW and RodA in ΔgpsB cells further suggest the existence of a single large PG assembly complex. Finally, we show that GpsB is required for septal localization and kinase activity of StkP, and therefore for StkP-dependent phosphorylation of DivIVA. Altogether, we propose that the StkP/DivIVA/GpsB triad finely tunes the two modes of peptidoglycan (peripheral and septal) synthesis responsible for the pneumococcal ellipsoid cell shape. Over the last decade, bacterial genomics have revealed the presence of eukaryotic-type serine/threonine protein kinases (STKPs) in many bacteria. However, their role and mode of action is still elusive. Recent studies have suggested that STKPs could play an important role in regulating cell division of some bacterial species but the underlying regulatory mechanisms are largely unknown. Considering that much remains to be discovered about the mechanisms by which the cell division machinery is assembled at the cell center and how the diversity of bacterial cell shapes is achieved and maintained, studying the role of STKPs represents a promising approach to decipher the inner workings of bacterial cell division. In this article, we show that the ser/thr-kinase StkP and the two cell division paralogs GpsB and DivIVA of Streptococcus pneumoniae (the pneumococcus) work together to finely tune peptidoglycan synthesis and achieve proper cell shape and division. We discuss the likelihood that similar mechanisms occur in other bacteria requiring protein-kinases for the cell division process. We propose that the interplay between protein-kinases and cell-division proteins like GpsB or DivIVA is of crucial importance to satisfy the modes of cell division and the cell shape displayed by streptococci and other bacteria.
Collapse
|
47
|
Bacterial cell division proteins as antibiotic targets. Bioorg Chem 2014; 55:27-38. [PMID: 24755375 DOI: 10.1016/j.bioorg.2014.03.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 11/21/2022]
Abstract
Proteins involved in bacterial cell division often do not have a counterpart in eukaryotic cells and they are essential for the survival of the bacteria. The genetic accessibility of many bacterial species in combination with the Green Fluorescence Protein revolution to study localization of proteins and the availability of crystal structures has increased our knowledge on bacterial cell division considerably in this century. Consequently, bacterial cell division proteins are more and more recognized as potential new antibiotic targets. An international effort to find small molecules that inhibit the cell division initiating protein FtsZ has yielded many compounds of which some are promising as leads for preclinical use. The essential transglycosylase activity of peptidoglycan synthases has recently become accessible to inhibitor screening. Enzymatic assays for and structural information on essential integral membrane proteins such as MraY and FtsW involved in lipid II (the peptidoglycan building block precursor) biosynthesis have put these proteins on the list of potential new targets. This review summarises and discusses the results and approaches to the development of lead compounds that inhibit bacterial cell division.
Collapse
|
48
|
Evans K, Stone V, Chen L, Ge X, Xu P. Systematic study of genes influencing cellular chain length in Streptococcus sanguinis. MICROBIOLOGY-SGM 2013; 160:307-315. [PMID: 24295823 PMCID: PMC3919539 DOI: 10.1099/mic.0.071688-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Streptococcus sanguinis is a Gram-positive bacterium that is indigenous to the oral cavity. S. sanguinis, a primary colonizer of the oral cavity, serves as a tether for the attachment of other oral pathogens. The colonization of microbes on the tooth surface forms dental plaque, which can lead to the onset of periodontal disease. We examined a comprehensive mutant library to identify genes related to cellular chain length and morphology using phase-contrast microscopy. A number of hypothetical genes related to the cellular chain length were identified in this study. Genes related to the cellular chain length were analysed along with clusters of orthologous groups (COG) for gene functions. It was discovered that the highest proportion of COG functions related to cellular chain length was 'cell division and chromosome separation'. However, different COG functions were also found to be related with altered cellular chain length. This suggested that different genes related with multiple mechanisms contribute to the cellular chain length in S. sanguinis SK36.
Collapse
Affiliation(s)
- Karra Evans
- VCU Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA
| | - Victoria Stone
- VCU Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA
| | - Lei Chen
- VCU Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA
| | - Xiuchun Ge
- VCU Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA
| | - Ping Xu
- VCU Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA
- Center for the Study of Biological Complexity of Virginia Commonwealth University, Richmond, VA, USA
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| |
Collapse
|
49
|
Do the divisome and elongasome share a common evolutionary past? Curr Opin Microbiol 2013; 16:745-51. [DOI: 10.1016/j.mib.2013.09.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 08/20/2013] [Accepted: 09/06/2013] [Indexed: 01/05/2023]
|
50
|
Abstract
For many years, bacteria were considered rather simple organisms, but the dogmatic notion that subcellular organization is a eukaryotic trait has been overthrown for more than a decade. The discovery of homologues of the eukaryotic cytoskeletal proteins actin, tubulin, and intermediate filaments in bacteria has been instrumental in changing this view. Over the past few years, we have gained an incredible level of insight into the diverse family of bacterial actins and their molecular workings. Here we review the functional, biochemical, and structural features of the most well-studied bacterial actins.
Collapse
Affiliation(s)
- Ertan Ozyamak
- Department of Plant and Microbial Biology, University of California , Berkeley, California 94720, United States
| | | | | |
Collapse
|