1
|
Muchová K, Pospíšil J, Kalocsaiová E, Chromiková Z, Žarnovičanová S, Šanderová H, Krásný L, Barák I. Spatio-temporal control of asymmetric septum positioning during sporulation in Bacillus subtilis. J Biol Chem 2024; 300:107339. [PMID: 38705388 PMCID: PMC11154705 DOI: 10.1016/j.jbc.2024.107339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/07/2024] Open
Abstract
During sporulation, Bacillus subtilis forms an asymmetric septum, dividing the cell into two compartments, a mother cell and a forespore. The site of asymmetric septation is linked to the membrane where FtsZ and SpoIIE initiate the formation of the Z-ring and the E-ring, respectively. These rings then serve as a scaffold for the other cell division and peptidoglycan synthesizing proteins needed to build the septum. However, despite decades of research, not enough is known about how the asymmetric septation site is determined. Here, we identified and characterized the interaction between SpoIIE and RefZ. We show that these two proteins transiently colocalize during the early stages of asymmetric septum formation when RefZ localizes primarily from the mother cell side of the septum. We propose that these proteins and their interplay with the spatial organization of the chromosome play a role in controlling asymmetric septum positioning.
Collapse
Affiliation(s)
- Katarína Muchová
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jiří Pospíšil
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Evelína Kalocsaiová
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Zuzana Chromiková
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Silvia Žarnovičanová
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Hana Šanderová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Libor Krásný
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic.
| | - Imrich Barák
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia.
| |
Collapse
|
2
|
Letzkus M, Trela C, Mera PE. Three factors ParA, TipN, and DnaA-mediated chromosome replication initiation are contributors of centromere segregation in Caulobacter crescentus. Mol Biol Cell 2024; 35:ar68. [PMID: 38568781 PMCID: PMC11151105 DOI: 10.1091/mbc.e23-12-0503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/05/2024] [Accepted: 03/25/2024] [Indexed: 04/05/2024] Open
Abstract
The ability of bacteria to maintain chromosomal integrity throughout their life cycle is crucial for survival. In Caulobacter crescentus, the polar factor TipN has been proposed to be involved with the partitioning system ParABS. Cells with tipN knocked out display subtle segregation defects of the centromere-like region parS. We hypothesized that TipN's role with parS segregation is obscured by other forces that are ParABS-independent. To test our hypothesis, we removed one of those forces - chromosome replication - and analyzed the role of TipN with ParA. We first confirm that ParA retains its ability to transport the centromeric region parS from the stalked pole to the opposite pole in the absence of chromosome replication. Our data revealed that in the absence of chromosome replication, TipN becomes essential for ParA's ability to transport parS. Furthermore, we identify a potential connection between the replication initiator DnaA and TipN. Although TipN is not essential for viability, tipN knockout cells lose viability when the regulation of DnaA levels is altered. Our data suggest that the DnaA-dependent susceptibility of tipN knockout cells is connected to parS segregation. Collectively, this work provides insights into the complex regulation involved in the coordination of chromosome replication and segregation in bacteria.
Collapse
Affiliation(s)
- Morgan Letzkus
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Corey Trela
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Paola E. Mera
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| |
Collapse
|
3
|
Chareyre S, Li X, Anjuwon-Foster BR, Updegrove TB, Clifford S, Brogan AP, Su Y, Zhang L, Chen J, Shroff H, Ramamurthi KS. Cell division machinery drives cell-specific gene activation during differentiation in Bacillus subtilis. Proc Natl Acad Sci U S A 2024; 121:e2400584121. [PMID: 38502707 PMCID: PMC10990147 DOI: 10.1073/pnas.2400584121] [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: 01/10/2024] [Accepted: 02/22/2024] [Indexed: 03/21/2024] Open
Abstract
When faced with starvation, the bacterium Bacillus subtilis transforms itself into a dormant cell type called a "spore". Sporulation initiates with an asymmetric division event, which requires the relocation of the core divisome components FtsA and FtsZ, after which the sigma factor σF is exclusively activated in the smaller daughter cell. Compartment-specific activation of σF requires the SpoIIE phosphatase, which displays a biased localization on one side of the asymmetric division septum and associates with the structural protein DivIVA, but the mechanism by which this preferential localization is achieved is unclear. Here, we isolated a variant of DivIVA that indiscriminately activates σF in both daughter cells due to promiscuous localization of SpoIIE, which was corrected by overproduction of FtsA and FtsZ. We propose that the core components of the redeployed cell division machinery drive the asymmetric localization of DivIVA and SpoIIE to trigger the initiation of the sporulation program.
Collapse
Affiliation(s)
- Sylvia Chareyre
- Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD20892
| | - Xuesong Li
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD20892
- HHMI, Ashburn, VA20147
| | | | - Taylor B. Updegrove
- Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD20892
| | - Sarah Clifford
- Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD20892
| | - Anna P. Brogan
- Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, MD20892
| | - Yijun Su
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD20892
- HHMI, Ashburn, VA20147
| | - Lixia Zhang
- Advanced Imaging and Microscopy Resource, NIH, Bethesda, MD20892
| | - Jiji Chen
- Advanced Imaging and Microscopy Resource, NIH, Bethesda, MD20892
| | - Hari Shroff
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD20892
- HHMI, Ashburn, VA20147
| | | |
Collapse
|
4
|
Letzkus M, Trela C, Mera PE. TipN's involvement with centromere segregation in Caulobacter crescentus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572679. [PMID: 38187783 PMCID: PMC10769339 DOI: 10.1101/2023.12.20.572679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Bacteria's ability to maintain chromosomal integrity throughout their life cycle is crucial for their survival. In Caulobacter crescentus, the polar factor TipN has been proposed to be involved with the partitioning system ParABS. However, cells with tipN knocked out display subtle parS segregation defects. We hypothesized that TipN's role with parS segregation is obscured by other forces that are ParABS-independent. To test our hypothesis, we removed one of those forces - chromosome replication - and analyzed the role of TipN with ParA. We first demonstrate that ParA retains its ability to transport the centromeric region parS from the stalked pole to the opposite pole in the absence of chromosome replication. Our data revealed that in the absence of chromosome replication, TipN becomes essential for ParA's ability to transport parS. Furthermore, we identify a potential connection between the replication initiator DnaA and TipN. Although TipN is not essential for viability, tipN knockout cells lose viability when the regulation of DnaA levels is altered. Our data suggest that the DnaA-dependent susceptibility of tipN knockout cells is connected to parS segregation. Collectively, this work provides insights into the complex regulation involved in the coordination of chromosome replication and segregation in bacteria.
Collapse
Affiliation(s)
- Morgan Letzkus
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Corey Trela
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Paola E. Mera
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| |
Collapse
|
5
|
Sutton JAF, Cooke M, Tinajero-Trejo M, Wacnik K, Salamaga B, Portman-Ross C, Lund VA, Hobbs JK, Foster SJ. The roles of GpsB and DivIVA in Staphylococcus aureus growth and division. Front Microbiol 2023; 14:1241249. [PMID: 37711690 PMCID: PMC10498921 DOI: 10.3389/fmicb.2023.1241249] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/04/2023] [Indexed: 09/16/2023] Open
Abstract
The spheroid bacterium Staphylococcus aureus is often used as a model of morphogenesis due to its apparently simple cell cycle. S. aureus has many cell division proteins that are conserved across bacteria alluding to common functions. However, despite intensive study, we still do not know the roles of many of these components. Here, we have examined the functions of the paralogues DivIVA and GpsB in the S. aureus cell cycle. Cells lacking gpsB display a more spherical phenotype than the wild-type cells, which is associated with a decrease in peripheral cell wall peptidoglycan synthesis. This correlates with increased localization of penicillin-binding proteins at the developing septum, notably PBPs 2 and 3. Our results highlight the role of GpsB as an apparent regulator of cell morphogenesis in S. aureus.
Collapse
Affiliation(s)
- Joshua A. F. Sutton
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Mark Cooke
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Mariana Tinajero-Trejo
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Katarzyna Wacnik
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Bartłomiej Salamaga
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Callum Portman-Ross
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Victoria A. Lund
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Jamie K. Hobbs
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
- Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom
| | - Simon J. Foster
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| |
Collapse
|
6
|
Roberts DM. A new role for monomeric ParA/Soj in chromosome dynamics in Bacillus subtilis. Microbiologyopen 2023; 12:e1344. [PMID: 36825885 PMCID: PMC9841721 DOI: 10.1002/mbo3.1344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/17/2023] Open
Abstract
ParABS (Soj-Spo0J) systems were initially implicated in plasmid and chromosome segregation in bacteria. However, it is now increasingly understood that they play multiple roles in cell cycle events in Bacillus subtilis, and possibly other bacteria. In a recent study, monomeric forms of ParA/Soj have been implicated in regulating aspects of chromosome dynamics during B. subtilis sporulation. In this commentary, I will discuss the known roles of ParABS systems, explore why sporulation is a valuable model for studying these proteins, and the new insights into the role of monomeric ParA/Soj. Finally, I will touch upon some of the future work that remains.
Collapse
|
7
|
Roberts DM, Anchimiuk A, Kloosterman TG, Murray H, Wu LJ, Gruber S, Errington J. Chromosome remodelling by SMC/Condensin in B. subtilis is regulated by monomeric Soj/ParA during growth and sporulation. Proc Natl Acad Sci U S A 2022; 119:e2204042119. [PMID: 36206370 PMCID: PMC9564211 DOI: 10.1073/pnas.2204042119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022] Open
Abstract
SMC complexes, loaded at ParB-parS sites, are key mediators of chromosome organization in bacteria. ParA/Soj proteins interact with ParB/Spo0J in a pathway involving adenosine triphosphate (ATP)-dependent dimerization and DNA binding, facilitating chromosome segregation in bacteria. In Bacillus subtilis, ParA/Soj also regulates DNA replication initiation and along with ParB/Spo0J is involved in cell cycle changes during endospore formation. The first morphological stage in sporulation is the formation of an elongated chromosome structure called an axial filament. Here, we show that a major redistribution of SMC complexes drives axial filament formation in a process regulated by ParA/Soj. Furthermore, and unexpectedly, this regulation is dependent on monomeric forms of ParA/Soj that cannot bind DNA or hydrolyze ATP. These results reveal additional roles for ParA/Soj proteins in the regulation of SMC dynamics in bacteria and yet further complexity in the web of interactions involving chromosome replication, segregation and organization, controlled by ParAB and SMC.
Collapse
Affiliation(s)
- David M. Roberts
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Anna Anchimiuk
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore, 015 Lausanne, Switzerland
| | - Tomas G. Kloosterman
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Heath Murray
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Ling Juan Wu
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| | - Stephan Gruber
- Department of Fundamental Microbiology, University of Lausanne, Bâtiment Biophore, 015 Lausanne, Switzerland
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, United Kingdom
| |
Collapse
|
8
|
RefZ and Noc Act Synthetically to Prevent Aberrant Divisions during Bacillus subtilis Sporulation. J Bacteriol 2022; 204:e0002322. [PMID: 35506695 DOI: 10.1128/jb.00023-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During sporulation, Bacillus subtilis undergoes an atypical cell division that requires overriding mechanisms that protect chromosomes from damage and ensure inheritance by daughter cells. Instead of assembling between segregated chromosomes at midcell, the FtsZ-ring coalesces polarly, directing division over one chromosome. The DNA-binding protein RefZ facilitates the timely assembly of polar Z-rings and partially defines the region of chromosome initially captured in the forespore. RefZ binds to motifs (RBMs) located proximal to the origin of replication (oriC). Although refZ and the RBMs are conserved across the Bacillus genus, a refZ deletion mutant sporulates with wild-type efficiency, so the functional significance of RefZ during sporulation remains unclear. To further investigate RefZ function, we performed a candidate-based screen for synthetic sporulation defects by combining ΔrefZ with deletions of genes previously implicated in FtsZ regulation and/or chromosome capture. Combining ΔrefZ with deletions of ezrA, sepF, parA, or minD did not detectably affect sporulation. In contrast, a ΔrefZ Δnoc mutant exhibited a sporulation defect, revealing a genetic interaction between RefZ and Noc. Using reporters of sporulation progression, we determined the ΔrefZ Δnoc mutant exhibited sporulation delays after Spo0A activation but prior to late sporulation, with a subset of cells failing to divide polarly or activate the first forespore-specific sigma factor, SigF. The ΔrefZ Δnoc mutant also exhibited extensive dysregulation of cell division, producing cells with extra, misplaced, or otherwise aberrant septa. Our results reveal a previously unknown epistatic relationship that suggests refZ and noc contribute synthetically to regulating cell division and supporting spore development. IMPORTANCE The DNA-binding protein RefZ and its binding sites (RBMs) are conserved in sequence and location on the chromosome across the Bacillus genus and contribute to the timing of polar FtsZ-ring assembly during sporulation. Only a small number of noncoding and nonregulatory DNA motifs are known to be conserved in chromosomal position in bacteria, suggesting there is strong selective pressure for their maintenance; however, a refZ deletion mutant sporulates efficiently, providing no clues as to their functional significance. Here, we find that in the absence of the nucleoid occlusion factor Noc, deletion of refZ results in a sporulation defect characterized by developmental delays and aberrant divisions.
Collapse
|
9
|
Tn
FLXopen
: Markerless Transposons for Functional Fluorescent Fusion Proteins and Protein Interaction Prediction. Microbiol Spectr 2022; 10:e0242821. [PMID: 35499319 PMCID: PMC9241775 DOI: 10.1128/spectrum.02428-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fluorescence microscopy of cells expressing proteins translationally linked to a fluorophore can be a powerful tool to investigate protein localization dynamics in vivo. One major obstacle to reliably analyze biologically relevant localization is the construction of a fusion protein that is both fluorescent and functional. Here, we develop a strategy to construct fluorescent fusions at theoretically any location in the protein by using TnFLXopen random transposon mutagenesis to randomly insert a gene encoding a fluorescent protein. Moreover, insertions within a target gene are enriched by an inducible gene-trap strategy and selection by fluorescence activated cell sorting. Using this approach, we isolate a variety of fluorescent fusions to FtsZ that exhibit ring-like localization and a fusion to the flagellar stator protein that both is functional for supporting motility and localizes as fluorescent puncta. Finally, we further modify TnFLXopen to insert the coding sequence for the C-terminal half of mVenus for use in bimolecular fluorescence complementation (BiFC) and the in vivo detection of protein-protein interaction candidates. As proof-of-concept, the DivIVA polar scaffolding protein was fused to the N terminus of mVenus, the C terminus of mVenus was delivered by transposition, and a combination of fluorescence activated cell sorter (FACS) sorting and whole-genome sequencing identified the known self-interaction of DivIVA as well as other possible candidate interactors. We suggest that the FACS selection is a viable alternative to antibiotic selection in transposon mutagenesis that can generate new fluorescent tools for in vivo protein characterization. IMPORTANCE Transposon mutagenesis is a powerful tool for random mutagenesis, as insertion of a transposon and accompanying antibiotic resistance cassette often disrupt gene function. Here, we present a series of transposons with fluorescent protein genes which, when integrated in frame, may be selected with a fluorescence activated cell sorter (FACS). An open reading frame runs continuously through the transposon such that fluorescent protein fusions may be inserted theoretically anywhere in the primary sequence and potentially preserve function of the target protein. Finally, the transposons were further modified to randomly insert a partial fluorescent protein compatible with bimolecular fluorescence complementation (BiFC) to identify protein interaction candidates.
Collapse
|
10
|
Labana P, Dornan MH, Lafrenière M, Czarny TL, Brown ED, Pezacki JP, Boddy CN. Armeniaspirols inhibit the AAA+ proteases ClpXP and ClpYQ leading to cell division arrest in Gram-positive bacteria. Cell Chem Biol 2021; 28:1703-1715.e11. [PMID: 34293284 DOI: 10.1016/j.chembiol.2021.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 04/22/2021] [Accepted: 06/29/2021] [Indexed: 01/16/2023]
Abstract
Multi-drug-resistant bacteria present an urgent threat to modern medicine, creating a desperate need for antibiotics with new modes of action. As natural products remain an unsurpassed source for clinically viable antibiotic compounds, we investigate the mechanism of action of armeniaspirol. The armeniaspirols are a structurally unique class of Gram-positive antibiotic discovered from Streptomyces armeniacus for which resistance cannot be readily obtained. We show that armeniaspirol inhibits the ATP-dependent proteases ClpXP and ClpYQ in vitro and in the model Gram-positive Bacillus subtilis. This inhibition dysregulates the divisome and elongasome supported by an upregulation of key proteins FtsZ, DivIVA, and MreB inducing cell division arrest. The inhibition of ClpXP and ClpYQ to dysregulate cell division represents a unique antibiotic mechanism of action and armeniaspirol is the only known natural product inhibitor of the coveted anti-virulence target ClpP. Thus, armeniaspirol possesses a promising lead scaffold for antibiotic development with unique pharmacology.
Collapse
Affiliation(s)
- Puneet Labana
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Mark H Dornan
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Matthew Lafrenière
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Tomasz L Czarny
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - John P Pezacki
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Christopher N Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| |
Collapse
|
11
|
Meunier A, Cornet F, Campos M. Bacterial cell proliferation: from molecules to cells. FEMS Microbiol Rev 2021; 45:fuaa046. [PMID: 32990752 PMCID: PMC7794046 DOI: 10.1093/femsre/fuaa046] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 09/10/2020] [Indexed: 12/11/2022] Open
Abstract
Bacterial cell proliferation is highly efficient, both because bacteria grow fast and multiply with a low failure rate. This efficiency is underpinned by the robustness of the cell cycle and its synchronization with cell growth and cytokinesis. Recent advances in bacterial cell biology brought about by single-cell physiology in microfluidic chambers suggest a series of simple phenomenological models at the cellular scale, coupling cell size and growth with the cell cycle. We contrast the apparent simplicity of these mechanisms based on the addition of a constant size between cell cycle events (e.g. two consecutive initiation of DNA replication or cell division) with the complexity of the underlying regulatory networks. Beyond the paradigm of cell cycle checkpoints, the coordination between the DNA and division cycles and cell growth is largely mediated by a wealth of other mechanisms. We propose our perspective on these mechanisms, through the prism of the known crosstalk between DNA replication and segregation, cell division and cell growth or size. We argue that the precise knowledge of these molecular mechanisms is critical to integrate the diverse layers of controls at different time and space scales into synthetic and verifiable models.
Collapse
Affiliation(s)
- Alix Meunier
- Centre de Biologie Intégrative de Toulouse (CBI Toulouse), Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Université de Toulouse, UPS, CNRS, IBCG, 165 rue Marianne Grunberg-Manago, 31062 Toulouse, France
| | - François Cornet
- Centre de Biologie Intégrative de Toulouse (CBI Toulouse), Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Université de Toulouse, UPS, CNRS, IBCG, 165 rue Marianne Grunberg-Manago, 31062 Toulouse, France
| | - Manuel Campos
- Centre de Biologie Intégrative de Toulouse (CBI Toulouse), Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Université de Toulouse, UPS, CNRS, IBCG, 165 rue Marianne Grunberg-Manago, 31062 Toulouse, France
| |
Collapse
|
12
|
Nordyke CT, Ahmed YM, Puterbaugh RZ, Bowman GR, Varga K. Intrinsically Disordered Bacterial Polar Organizing Protein Z, PopZ, Interacts with Protein Binding Partners Through an N-terminal Molecular Recognition Feature. J Mol Biol 2020; 432:6092-6107. [PMID: 33058876 DOI: 10.1016/j.jmb.2020.09.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/18/2020] [Accepted: 09/25/2020] [Indexed: 11/15/2022]
Abstract
The polar organizing protein Z (PopZ) is necessary for the formation of three-dimensional microdomains at the cell poles in Caulobacter crescentus, where it functions as a hub protein that recruits multiple regulatory proteins from the cytoplasm. Although a large portion of the protein is predicted to be natively unstructured, in reconstituted systems PopZ can self-assemble into a macromolecular scaffold that directly binds to at least ten different proteins. Here we report the solution NMR structure of PopZΔ134-177, a truncated form of PopZ that does not self-assemble but retains the ability to interact with heterologous proteins. We show that the unbound form of PopZΔ134-177 is unstructured in solution, with the exception of a small amphipathic α-helix in residues M10-I17, which is included within a highly conserved region near the N-terminal. In applying NMR techniques to map the interactions between PopZΔ134-177 and one of its binding partners, RcdA, we find evidence that the α-helix and adjoining amino acids extending to position E23 serve as the core of the binding motif. Consistent with this, a point mutation at position I17 severely compromises binding. Our results show that a partially structured Molecular Recognition Feature (MoRF) within an intrinsically disordered domain of PopZ contributes to the assembly of polar microdomains, revealing a structural basis for complex network assembly in Alphaproteobacteria that is analogous to those formed by intrinsically disordered hub proteins in other kingdoms.
Collapse
Affiliation(s)
- Christopher T Nordyke
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, United States
| | - Yasin M Ahmed
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, United States
| | - Ryan Z Puterbaugh
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, United States
| | - Grant R Bowman
- Department of Molecular Biology, University of Wyoming, Laramie, WY 82071, United States.
| | - Krisztina Varga
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, United States.
| |
Collapse
|
13
|
Cohesion of Sister Chromosome Termini during the Early Stages of Sporulation in Bacillus subtilis. J Bacteriol 2020; 202:JB.00296-20. [PMID: 32778559 PMCID: PMC7515245 DOI: 10.1128/jb.00296-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/31/2020] [Indexed: 11/28/2022] Open
Abstract
During sporulation of Bacillus subtilis, the cell cycle is reorganized to generate separated prespore and mother cell compartments, each containing a single fully replicated chromosome. The process begins with reorganization of the nucleoid to form an elongated structure, the axial filament, in which the two chromosome origins are attached to opposite cell poles, with the remainder of the DNA stretched between these sites. When the cell then divides asymmetrically, the division septum closes around the chromosome destined for the smaller prespore, trapping the origin-proximal third of the chromosome in the prespore. A translocation pore is assembled through which a DNA transporter, SpoIIIE/FtsK, transfers the bulk of the chromosome to complete the segregation process. Although the mechanisms involved in attaching origin regions to the cell poles are quite well understood, little is known about other aspects of axial filament morphology. We have studied the behavior of the terminus region of the chromosome during sporulation using time-lapse imaging of wild-type and mutant cells. The results suggest that the elongated structure involves cohesion of the terminus regions of the sister chromosomes and that this cohesion is resolved when the termini reach the asymmetric septum or translocation pore. Possible mechanisms and roles of cohesion and resolution are discussed.IMPORTANCE Endospore formation in Firmicutes bacteria provides one of the most highly resistant life forms on earth. During the early stages of endospore formation, the cell cycle is reorganized so that exactly two fully replicated chromosomes are generated, before the cell divides asymmetrically to generate the prespore and mother cell compartments that are critical for the developmental process. Decades ago, it was discovered that just prior to asymmetrical division the two chromosomes enter an unusual elongated configuration called the axial filament. This paper provides new insights into the nature of the axial filament structure and suggests that cohesion of the normally separated sister chromosome termini plays an important role in axial filament formation.
Collapse
|
14
|
Wu LJ, Lee S, Park S, Eland LE, Wipat A, Holden S, Errington J. Geometric principles underlying the proliferation of a model cell system. Nat Commun 2020; 11:4149. [PMID: 32811832 PMCID: PMC7434903 DOI: 10.1038/s41467-020-17988-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/24/2020] [Indexed: 02/07/2023] Open
Abstract
Many bacteria can form wall-deficient variants, or L-forms, that divide by a simple mechanism that does not require the FtsZ-based cell division machinery. Here, we use microfluidic systems to probe the growth, chromosome cycle and division mechanism of Bacillus subtilis L-forms. We find that forcing cells into a narrow linear configuration greatly improves the efficiency of cell growth and chromosome segregation. This reinforces the view that L-form division is driven by an excess accumulation of surface area over volume. Cell geometry also plays a dominant role in controlling the relative positions and movement of segregating chromosomes. Furthermore, the presence of the nucleoid appears to influence division both via a cell volume effect and by nucleoid occlusion, even in the absence of FtsZ. Our results emphasise the importance of geometric effects for a range of crucial cell functions, and are of relevance for efforts to develop artificial or minimal cell systems.
Collapse
Affiliation(s)
- Ling Juan Wu
- Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| | - Seoungjun Lee
- grid.1006.70000 0001 0462 7212Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX UK ,grid.13097.3c0000 0001 2322 6764Present Address: Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, SE5 9RX UK
| | - Sungshic Park
- grid.1006.70000 0001 0462 7212Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX UK ,grid.1006.70000 0001 0462 7212Interdisciplinary Computing and Complex BioSystems research group, School of Computing, Newcastle University, Newcastle upon Tyne, NE4 5TG UK
| | - Lucy E. Eland
- grid.1006.70000 0001 0462 7212Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX UK ,grid.1006.70000 0001 0462 7212Interdisciplinary Computing and Complex BioSystems research group, School of Computing, Newcastle University, Newcastle upon Tyne, NE4 5TG UK
| | - Anil Wipat
- grid.1006.70000 0001 0462 7212Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX UK ,grid.1006.70000 0001 0462 7212Interdisciplinary Computing and Complex BioSystems research group, School of Computing, Newcastle University, Newcastle upon Tyne, NE4 5TG UK
| | - Séamus Holden
- grid.1006.70000 0001 0462 7212Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX UK
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Biosciences Institute, Medical School, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
| |
Collapse
|
15
|
Pióro M, Jakimowicz D. Chromosome Segregation Proteins as Coordinators of Cell Cycle in Response to Environmental Conditions. Front Microbiol 2020; 11:588. [PMID: 32351468 PMCID: PMC7174722 DOI: 10.3389/fmicb.2020.00588] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/18/2020] [Indexed: 12/11/2022] Open
Abstract
Chromosome segregation is a crucial stage of the cell cycle. In general, proteins involved in this process are DNA-binding proteins, and in most bacteria, ParA and ParB are the main players; however, some bacteria manage this process by employing other proteins, such as condensins. The dynamic interaction between ParA and ParB drives movement and exerts positioning of the chromosomal origin of replication (oriC) within the cell. In addition, both ParA and ParB were shown to interact with the other proteins, including those involved in cell division or cell elongation. The significance of these interactions for the progression of the cell cycle is currently under investigation. Remarkably, DNA binding by ParA and ParB as well as their interactions with protein partners conceivably may be modulated by intra- and extracellular conditions. This notion provokes the question of whether chromosome segregation can be regarded as a regulatory stage of the cell cycle. To address this question, we discuss how environmental conditions affect chromosome segregation and how segregation proteins influence other cell cycle processes.
Collapse
Affiliation(s)
- Monika Pióro
- Department of Molecular Microbiology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Dagmara Jakimowicz
- Department of Molecular Microbiology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| |
Collapse
|
16
|
Ramm B, Heermann T, Schwille P. The E. coli MinCDE system in the regulation of protein patterns and gradients. Cell Mol Life Sci 2019; 76:4245-4273. [PMID: 31317204 PMCID: PMC6803595 DOI: 10.1007/s00018-019-03218-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/27/2019] [Accepted: 07/02/2019] [Indexed: 12/22/2022]
Abstract
Molecular self-organziation, also regarded as pattern formation, is crucial for the correct distribution of cellular content. The processes leading to spatiotemporal patterns often involve a multitude of molecules interacting in complex networks, so that only very few cellular pattern-forming systems can be regarded as well understood. Due to its compositional simplicity, the Escherichia coli MinCDE system has, thus, become a paradigm for protein pattern formation. This biological reaction diffusion system spatiotemporally positions the division machinery in E. coli and is closely related to ParA-type ATPases involved in most aspects of spatiotemporal organization in bacteria. The ATPase MinD and the ATPase-activating protein MinE self-organize on the membrane as a reaction matrix. In vivo, these two proteins typically oscillate from pole-to-pole, while in vitro they can form a variety of distinct patterns. MinC is a passenger protein supposedly operating as a downstream cue of the system, coupling it to the division machinery. The MinCDE system has helped to extract not only the principles underlying intracellular patterns, but also how they are shaped by cellular boundaries. Moreover, it serves as a model to investigate how patterns can confer information through specific and non-specific interactions with other molecules. Here, we review how the three Min proteins self-organize to form patterns, their response to geometric boundaries, and how these patterns can in turn induce patterns of other molecules, focusing primarily on experimental approaches and developments.
Collapse
Affiliation(s)
- Beatrice Ramm
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Tamara Heermann
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Petra Schwille
- Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany.
| |
Collapse
|
17
|
Abstract
Reproduction in the bacterial kingdom predominantly occurs through binary fission-a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped Escherichia coli and Bacillus subtilis, which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.
Collapse
|
18
|
A DNA-Binding Protein Tunes Septum Placement during Bacillus subtilis Sporulation. J Bacteriol 2019; 201:JB.00287-19. [PMID: 31160399 PMCID: PMC6657595 DOI: 10.1128/jb.00287-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 05/15/2019] [Indexed: 01/07/2023] Open
Abstract
Bacillus subtilis is a bacterium capable of differentiating into a spore form more resistant to environmental stress. Early in sporulation, each cell possesses two copies of a circular chromosome. A polar FtsZ ring (Z ring) directs septation over one of the chromosomes, generating two cell compartments. The smaller "forespore" compartment initially contains only 25 to 30% of one chromosome, and this transient genetic asymmetry is required for differentiation. Timely assembly of polar Z rings and precise capture of the chromosome in the forespore both require the DNA-binding protein RefZ. To mediate its role in chromosome capture, RefZ must bind to specific DNA motifs (RBMs) that localize near the poles at the time of septation. Cells artificially induced to express RefZ during vegetative growth cannot assemble Z rings, an effect that also requires DNA binding. We hypothesized that RefZ-RBM complexes mediate precise chromosome capture by modulating FtsZ function. To investigate, we isolated 10 RefZ loss-of-function (rLOF) variants unable to inhibit cell division yet still capable of binding RBMs. Sporulating cells expressing the rLOF variants in place of wild-type RefZ phenocopied a ΔrefZ mutant, suggesting that RefZ acts through an FtsZ-dependent mechanism. The crystal structure of RefZ was solved, and wild-type RefZ and the rLOF variants were further characterized. Our data suggest that RefZ's oligomerization state and specificity for the RBMs are critical determinants influencing RefZ's ability to affect FtsZ dynamics. We propose that RBM-bound RefZ complexes function as a developmentally regulated nucleoid occlusion system for fine-tuning the position of the septum relative to the chromosome during sporulation.IMPORTANCE The bacterial nucleoid forms a large, highly organized structure. Thus, in addition to storing the genetic code, the nucleoid harbors positional information that can be leveraged by DNA-binding proteins to spatially constrain cellular activities. During B. subtilis sporulation, the nucleoid undergoes reorganization, and the cell division protein FtsZ assembles polarly to direct septation over one chromosome. The TetR family protein RefZ binds DNA motifs (RBMs) localized near the poles at the time of division and is required for both timely FtsZ assembly and precise capture of DNA in the future spore compartment. Our data suggest that RefZ exploits nucleoid organization by associating with polarly localized RBMs to modulate the positioning of FtsZ relative to the chromosome during sporulation.
Collapse
|
19
|
DNA-Membrane Anchor Facilitates Efficient Chromosome Translocation at a Distance in Bacillus subtilis. mBio 2019; 10:mBio.01117-19. [PMID: 31239381 PMCID: PMC6593407 DOI: 10.1128/mbio.01117-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
To properly segregate their chromosomes, organisms tightly regulate the organization and dynamics of their DNA. Aspects of the process by which DNA is translocated during sporulation are not yet fully understood, such as what factors indirectly influence the activity of the motor protein SpoIIIE. In this work, we have shown that a DNA-membrane tether mediated by RacA contributes to the activity of SpoIIIE. Loss of RacA nearly doubles the time of translocation, despite the physically distinct locations these proteins and their activities occupy within the cell. This is a rare example of an explicit effect that DNA-membrane connections can have on cell physiology and demonstrates that distant changes to the state of the chromosome can influence motor proteins which act upon it. Chromosome segregation in sporulating Bacillus subtilis involves the tethering of sister chromosomes at opposite cell poles. RacA is known to mediate chromosome tethering by interacting with both centromere-like elements in the DNA and with DivIVA, a membrane protein which localizes to the cell poles. RacA has a secondary function in which it assists in nucleoid condensation. Here we demonstrate that, in addition to positioning and condensing the chromosome, RacA contributes to efficient transport of DNA by the chromosome segregation motor SpoIIIE. When RacA is deleted, one-quarter of cells fail to capture DNA in the nascent spore, yet 70% of cells fail to form viable spores without RacA. This discrepancy indicates that RacA possesses a role in sporulation beyond DNA capture and condensation. We observed that the mutant cells had reduced chromosome translocation into the forespore across the entire length of the chromosome, requiring nearly twice as much time to move a given DNA locus. Additionally, functional abolition of the RacA-DivIVA interaction reduced translocation to a similar degree as in a racA deletion strain, demonstrating the importance of the RacA-mediated tether in translocation and chromosome packaging during sporulation. We propose that the DNA-membrane anchor facilitates efficient translocation by SpoIIIE, not through direct protein-protein contacts but by virtue of physical effects on the chromosome that arise from anchoring DNA at a distance.
Collapse
|
20
|
Random Chromosome Partitioning in the Polyploid Bacterium Thermus thermophilus HB27. G3-GENES GENOMES GENETICS 2019; 9:1249-1261. [PMID: 30792193 PMCID: PMC6469415 DOI: 10.1534/g3.119.400086] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Little is known about chromosome segregation in polyploid prokaryotes. In this study, whether stringent or variable chromosome segregation occurs in polyploid thermophilic bacterium Thermus thermophilus was analyzed. A stable heterozygous strain (HL01) containing two antibiotic resistance markers at one gene locus was generated. The inheritance of the two alleles in the progeny of the heterozygous strain was then followed. During incubation without selection pressure, the fraction of heterozygous cells decreased and that of homozygous cells increased, while the relative abundance of each allele in the whole population remained constant, suggesting chromosome segregation had experienced random event. Consistently, in comparison with Bacillus subtilis in which the sister chromosomes were segregated equally, the ratios of DNA content in two daughter cells of T. thermophilus had a broader distribution and a larger standard deviation, indicating that the DNA content in the two daughter cells was not always identical. Further, the protein homologs (i.e., ParA and MreB) which have been suggested to be involved in bacterial chromosome partitioning did not actively participate in the chromosome segregation in T. thermophilus. Therefore, it seems that protein-based chromosome segregation machineries are less critical for the polyploid T. thermophilus, and chromosome segregation in this bacterium are not stringently controlled but tend to be variable, and random segregation can occur.
Collapse
|
21
|
Barák I, Muchová K, Labajová N. Asymmetric cell division during Bacillus subtilis sporulation. Future Microbiol 2019; 14:353-363. [PMID: 30855188 DOI: 10.2217/fmb-2018-0338] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacillus subtilis is a rod-shaped bacterium which divides precisely at mid-cell during vegetative growth. Unlike Escherichia coli, another model organism used for studying cell division, B. subtilis can also divide asymmetrically during sporulation, the simplest cell differentiation process. The asymmetrically positioned sporulation septum serves as a morphological foundation for establishing differential gene expression in the smaller forespore and larger mother cell. Both vegetative and sporulation septation events are fine-tuned with cell cycle, and placement of both septa are highly precise. We understand in some detail how this is achieved during vegetative growth but have limited information about how the asymmetric septation site is determined during sporulation.
Collapse
Affiliation(s)
- Imrich Barák
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarína Muchová
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Naďa Labajová
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| |
Collapse
|
22
|
Affiliation(s)
- Ashoka Chary Taviti
- Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, India
- Manipal Academy of Higher Education, Manipal, India
| | - Tushar Kant Beuria
- Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, India
| |
Collapse
|
23
|
Pióro M, Małecki T, Portas M, Magierowska I, Trojanowski D, Sherratt D, Zakrzewska-Czerwińska J, Ginda K, Jakimowicz D. Competition between DivIVA and the nucleoid for ParA binding promotes segrosome separation and modulates mycobacterial cell elongation. Mol Microbiol 2018; 111:204-220. [PMID: 30318635 PMCID: PMC7379644 DOI: 10.1111/mmi.14149] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2018] [Indexed: 01/03/2023]
Abstract
Although mycobacteria are rod shaped and divide by simple binary fission, their cell cycle exhibits unusual features: unequal cell division producing daughter cells that elongate with different velocities, as well as asymmetric chromosome segregation and positioning throughout the cell cycle. As in other bacteria, mycobacterial chromosomes are segregated by pair of proteins, ParA and ParB. ParA is an ATPase that interacts with nucleoprotein ParB complexes – segrosomes and non‐specifically binds the nucleoid. Uniquely in mycobacteria, ParA interacts with a polar protein DivIVA (Wag31), responsible for asymmetric cell elongation, however the biological role of this interaction remained unknown. We hypothesised that this interaction plays a critical role in coordinating chromosome segregation with cell elongation. Using a set of ParA mutants, we determined that disruption of ParA‐DNA binding enhanced the interaction between ParA and DivIVA, indicating a competition between the nucleoid and DivIVA for ParA binding. Having identified the ParA mutation that disrupts its recruitment to DivIVA, we found that it led to inefficient segrosomes separation and increased the cell elongation rate. Our results suggest that ParA modulates DivIVA activity. Thus, we demonstrate that the ParA‐DivIVA interaction facilitates chromosome segregation and modulates cell elongation.
Collapse
Affiliation(s)
- Monika Pióro
- Laboratory of Molecular Biology of Microorganisms, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Tomasz Małecki
- Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Magda Portas
- Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Izabela Magierowska
- Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Damian Trojanowski
- Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - David Sherratt
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Jolanta Zakrzewska-Czerwińska
- Laboratory of Molecular Biology of Microorganisms, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland.,Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Katarzyna Ginda
- Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland.,Department of Biochemistry, University of Oxford, Oxford, UK
| | - Dagmara Jakimowicz
- Laboratory of Molecular Biology of Microorganisms, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland.,Faculty of Biotechnology, Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| |
Collapse
|
24
|
Barák I, Muchová K. The positioning of the asymmetric septum during sporulation in Bacillus subtilis. PLoS One 2018; 13:e0201979. [PMID: 30092000 PMCID: PMC6084994 DOI: 10.1371/journal.pone.0201979] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/25/2018] [Indexed: 11/28/2022] Open
Abstract
Probably one of the most controversial questions about the cell division of Bacillus subtilis, a rod-shaped bacterium, concerns the mechanism that ensures correct division septum placement-at mid-cell during vegetative growth but closer to one end during sporulation. In general, bacteria multiply by binary fission, in which the division septum forms almost exactly at the cell centre. How the division machinery achieves such accuracy is a question of continuing interest. We understand in some detail how this is achieved during vegetative growth in Escherichia coli and B. subtilis, where two main negative regulators, nucleoid occlusion and the Min system, help to determine the division site, but we still do not know exactly how the asymmetric septation site is determined during sporulation in B. subtilis. Clearly, the inhibitory effects of the nucleoid occlusion and Min system on polar division have to be overcome. We evaluated the positioning of the asymmetric septum and its accuracy by statistical analysis of the site of septation. We also clarified the role of SpoIIE, RefZ and MinCD on the accuracy of this process. We determined that the sporulation septum forms approximately 1/6 of a cell length from one of the cell poles with high precision and that SpoIIE, RefZ and MinCD have a crucial role in precisely localizing the sporulation septum. Our results strongly support the idea that asymmetric septum formation is a very precise and highly controlled process regulated by a still unknown mechanism.
Collapse
Affiliation(s)
- Imrich Barák
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarína Muchová
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| |
Collapse
|
25
|
Valenčíková R, Krascsenitsová E, Labajová N, Makroczyová J, Barák I. Clostridial DivIVA and MinD interact in the absence of MinJ. Anaerobe 2018; 50:22-31. [PMID: 29408597 DOI: 10.1016/j.anaerobe.2018.01.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/04/2018] [Accepted: 01/29/2018] [Indexed: 11/25/2022]
Abstract
One of the key regulators ensuring proper Z-ring placement in rod-shaped bacteria is the Min system. It does so by creating a concentration gradient of the MinC septation inhibitor along the cell axis. In Escherichia coli, this gradient is established by a MinE-mediated pole-to-pole oscillation of the MinCDE complex. In Bacillus subtilis, the creation of an inhibitory gradient relies on the MinJ and DivIVA pair of topological determinants, which target MinCD to the newly formed cell poles. Introducing the E. coli oscillating Min system into B. subtilis leads to a sporulation defect, suggesting that oscillation is incompatible with sporulation. However, Clostridia, close endospore-forming relatives of Bacilli, do encode oscillating Min homologues in various combinations together with homologues from the less dynamic B. subtilis Min system. Here we address the questions of how these two systems could exist side-by-side and how they influence one another by studying the Clostridium beijerinckii and Clostridium difficile Min systems. The toolbox of genetic manipulations and fluorescent protein fusions in Clostridia is limited, therefore B. subtilis and E. coli were chosen as heterologous systems for studying these proteins. In B. subtilis, MinD and DivIVA interact through MinJ; here, however, we discovered that the MinD and DivIVA proteins of both C. difficile, and C. beijerinckii, interact directly, which is surprising in the latter case, since that organism also encodes a MinJ homologue. We confirm this interaction using both in vitro and in vivo methods. We also show that C. beijerinckii MinJ is probably not in direct contact with DivIVACb and, unlike B. subtilis MinJ, does not mediate the MinDCb and DivIVACb interaction. Our results suggest that the Clostridia Min system uses a new mechanism of function.
Collapse
Affiliation(s)
- Romana Valenčíková
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Eva Krascsenitsová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Naďa Labajová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Jana Makroczyová
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Imrich Barák
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia.
| |
Collapse
|
26
|
Genetic Dissection of DivIVA Functions in Listeria monocytogenes. J Bacteriol 2017; 199:JB.00421-17. [PMID: 28972021 DOI: 10.1128/jb.00421-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 09/22/2017] [Indexed: 12/30/2022] Open
Abstract
DivIVA is a membrane binding protein that clusters at curved membrane regions, such as the cell poles and the membrane invaginations occurring during cell division. DivIVA proteins recruit many other proteins to these subcellular sites through direct protein-protein interactions. DivIVA-dependent functions are typically associated with cell growth and division, even though species-specific differences in the spectrum of DivIVA functions and their causative interaction partners exist. DivIVA from the Gram-positive human pathogen Listeria monocytogenes has at least three different functions. In this bacterium, DivIVA is required for precise positioning of the septum at midcell, it contributes to the secretion of autolysins required for the breakdown of peptidoglycan at the septum after the completion of cell division, and it is essential for flagellar motility. While the DivIVA interaction partners for control of division site selection are well established, the proteins connecting DivIVA with autolysin secretion or swarming motility are completely unknown. We set out to identify divIVA alleles in which these three DivIVA functions could be separated, since the question of the degree to which the three functions of L. monocytogenes DivIVA are interlinked could not be answered before. Here, we identify such alleles, and our results show that division site selection, autolysin secretion, and swarming represent three discrete pathways that are independently influenced by DivIVA. These findings provide the required basis for the identification of DivIVA interaction partners controlling autolysin secretion and swarming in the future.IMPORTANCE DivIVA of the pathogenic bacterium Listeria monocytogenes is a central scaffold protein that influences at least three different cellular processes, namely, cell division, protein secretion, and bacterial motility. How DivIVA coordinates these rather unrelated processes is not known. We here identify variants of L. monocytogenes DivIVA, in which these functions are separated from each other. These results have important implications for the models explaining how DivIVA interacts with other proteins.
Collapse
|
27
|
Bottomley AL, Liew ATF, Kusuma KD, Peterson E, Seidel L, Foster SJ, Harry EJ. Coordination of Chromosome Segregation and Cell Division in Staphylococcus aureus. Front Microbiol 2017; 8:1575. [PMID: 28878745 PMCID: PMC5572376 DOI: 10.3389/fmicb.2017.01575] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/03/2017] [Indexed: 12/03/2022] Open
Abstract
Productive bacterial cell division and survival of progeny requires tight coordination between chromosome segregation and cell division to ensure equal partitioning of DNA. Unlike rod-shaped bacteria that undergo division in one plane, the coccoid human pathogen Staphylococcus aureus divides in three successive orthogonal planes, which requires a different spatial control compared to rod-shaped cells. To gain a better understanding of how this coordination between chromosome segregation and cell division is regulated in S. aureus, we investigated proteins that associate with FtsZ and the divisome. We found that DnaK, a well-known chaperone, interacts with FtsZ, EzrA and DivIVA, and is required for DivIVA stability. Unlike in several rod shaped organisms, DivIVA in S. aureus associates with several components of the divisome, as well as the chromosome segregation protein, SMC. This data, combined with phenotypic analysis of mutants, suggests a novel role for S. aureus DivIVA in ensuring cell division and chromosome segregation are coordinated.
Collapse
Affiliation(s)
- Amy L Bottomley
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Andrew T F Liew
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Kennardy D Kusuma
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Elizabeth Peterson
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Lisa Seidel
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Simon J Foster
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of SheffieldSheffield, United Kingdom
| | - Elizabeth J Harry
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| |
Collapse
|
28
|
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
|
29
|
Vega-Cabrera LA, Wood CD, Pardo-López L. Spo0M: structure and function beyond regulation of sporulation. Curr Genet 2017; 64:17-23. [PMID: 28577219 DOI: 10.1007/s00294-017-0718-3] [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: 05/11/2017] [Revised: 05/23/2017] [Accepted: 05/27/2017] [Indexed: 11/29/2022]
Abstract
In this mini-review, we present a perspective on the recent findings relating Spo0M structure and function that will stimulate and guide further studies in the characterization of this interesting protein. Cell division and sporulation constitute two of the best studied processes in the model organism Bacillus subtilis; however, there are many missing pieces in the giant regulatory puzzle that governs the independent and shared networks between them. Spo0M is a little studied protein that has been related to both, cell division and sporulation, but its biochemical function and its direct interactions have not been yet defined. Structural analysis of Spo0M revealed the presence of an arrestin-like domain and an FP domain (a dimerization domain present in proteasome elements), motifs more commonly found in eukaryotic proteins. The aim of this perspective is to present open questions regarding the functional and structural features of Spo0M that make this protein a good candidate for the ancestor of arrestins in bacteria and an important element in developmental and differentiation processes of Bacillus subtilis.
Collapse
Affiliation(s)
- Luz Adriana Vega-Cabrera
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad #2001, Apdo. Postal 510-3, 62250, Cuernavaca, Morelos, Mexico
| | - Christopher D Wood
- Laboratorio Nacional de Microscopía Avanzada, Universidad Nacional Autónoma de México, Av. Universidad #2001, Apdo. Postal 510-3, 62250, Cuernavaca, Morelos, Mexico
| | - Liliana Pardo-López
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad #2001, Apdo. Postal 510-3, 62250, Cuernavaca, Morelos, Mexico.
| |
Collapse
|
30
|
Abstract
Bacillus subtilis is the best described member of the Gram positive bacteria. It is a typical rod shaped bacterium and grows by elongation in its long axis, before dividing at mid cell to generate two similar daughter cells. B. subtilis is a particularly interesting model for cell cycle studies because it also carries out a modified, asymmetrical division during endospore formation, which can be simply induced by starvation. Cell growth occurs strictly by elongation of the rod, which maintains a constant diameter at all growth rates. This process involves expansion of the cell wall, requiring intercalation of new peptidoglycan and teichoic acid material, as well as controlled hydrolysis of existing wall material. Actin-like MreB proteins are the key spatial regulators that orchestrate the plethora of enzymes needed for cell elongation, many of which are thought to assemble into functional complexes called elongasomes. Cell division requires a switch in the orientation of cell wall synthesis and is organised by a tubulin-like protein FtsZ. FtsZ forms a ring-like structure at the site of impending division, which is specified by a range of mainly negative regulators. There it recruits a set of dedicated division proteins to form a structure called the divisome, which brings about the process of division. During sporulation, both the positioning and fine structure of the division septum are altered, and again, several dedicated proteins that contribute specifically to this process have been identified. This chapter summarises our current understanding of elongation and division in B. subtilis, with particular emphasis on the cytoskeletal proteins MreB and FtsZ, and highlights where the major gaps in our understanding remain.
Collapse
|
31
|
Koo BM, Kritikos G, Farelli JD, Todor H, Tong K, Kimsey H, Wapinski I, Galardini M, Cabal A, Peters JM, Hachmann AB, Rudner DZ, Allen KN, Typas A, Gross CA. Construction and Analysis of Two Genome-Scale Deletion Libraries for Bacillus subtilis. Cell Syst 2017; 4:291-305.e7. [PMID: 28189581 DOI: 10.1016/j.cels.2016.12.013] [Citation(s) in RCA: 348] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 11/19/2016] [Accepted: 12/21/2016] [Indexed: 12/16/2022]
Abstract
A systems-level understanding of Gram-positive bacteria is important from both an environmental and health perspective and is most easily obtained when high-quality, validated genomic resources are available. To this end, we constructed two ordered, barcoded, erythromycin-resistance- and kanamycin-resistance-marked single-gene deletion libraries of the Gram-positive model organism, Bacillus subtilis. The libraries comprise 3,968 and 3,970 genes, respectively, and overlap in all but four genes. Using these libraries, we update the set of essential genes known for this organism, provide a comprehensive compendium of B. subtilis auxotrophic genes, and identify genes required for utilizing specific carbon and nitrogen sources, as well as those required for growth at low temperature. We report the identification of enzymes catalyzing several missing steps in amino acid biosynthesis. Finally, we describe a suite of high-throughput phenotyping methodologies and apply them to provide a genome-wide analysis of competence and sporulation. Altogether, we provide versatile resources for studying gene function and pathway and network architecture in Gram-positive bacteria.
Collapse
Affiliation(s)
- Byoung-Mo Koo
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - George Kritikos
- European Molecular Biology Laboratory, Genome Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | | | - Horia Todor
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kenneth Tong
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Harvey Kimsey
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Ilan Wapinski
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Marco Galardini
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Angelo Cabal
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jason M Peters
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Anna-Barbara Hachmann
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - David Z Rudner
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Karen N Allen
- Department of Chemistry, Boston University, Boston, MA 02215, USA
| | - Athanasios Typas
- European Molecular Biology Laboratory, Genome Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute of Quantitative Biology, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
32
|
Kois-Ostrowska A, Strzałka A, Lipietta N, Tilley E, Zakrzewska-Czerwińska J, Herron P, Jakimowicz D. Unique Function of the Bacterial Chromosome Segregation Machinery in Apically Growing Streptomyces - Targeting the Chromosome to New Hyphal Tubes and its Anchorage at the Tips. PLoS Genet 2016; 12:e1006488. [PMID: 27977672 PMCID: PMC5157956 DOI: 10.1371/journal.pgen.1006488] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/16/2016] [Indexed: 01/26/2023] Open
Abstract
The coordination of chromosome segregation with cell growth is fundamental to the proliferation of any organism. In most unicellular bacteria, chromosome segregation is strictly coordinated with cell division and involves ParA that moves the ParB nucleoprotein complexes bi- or unidirectionally toward the cell pole(s). However, the chromosome organization in multiploid, apically extending and branching Streptomyces hyphae challenges the known mechanisms of bacterial chromosome segregation. The complex Streptomyces life cycle involves two stages: vegetative growth and sporulation. In the latter stage, multiple cell divisions accompanied by chromosome compaction and ParAB assisted segregation turn multigenomic hyphal cell into a chain of unigenomic spores. However, the requirement for active chromosome segregation is unclear in the absence of canonical cell division during vegetative growth except in the process of branch formation. The mechanism by which chromosomes are targeted to new hyphae in streptomycete vegetative growth has remained unknown until now. Here, we address the question of whether active chromosome segregation occurs at this stage. Applied for the first time in Streptomyces, labelling of the chromosomal replication initiation region (oriC) and time-lapse microscopy, revealed that in vegetative hyphae every copy of the chromosome is complexed with ParB, whereas ParA, through interaction with the apical protein complex (polarisome), tightly anchors only one chromosome at the hyphal tip. The anchor is maintained during replication, when ParA captures one of the daughter oriCs. During spore germination and branching, ParA targets one of the multiple chromosomal copies to the new hyphal tip, enabling efficient elongation of hyphal tube. Thus, our studies reveal a novel role for ParAB proteins during hyphal tip establishment and extension. To proliferate, cells synchronize growth and division with chromosome segregation. In unicellular bacteria, chromosomes segregate during replication by active movement of nucleoprotein complexes toward the cell pole(s). Here, we asked the question how active chromosome segregation occurs in the absence of cell division, during hyphal growth and branching of the filamentous bacterium, Streptomyces coelicolor. We show that in multigenomic Streptomyces hyphae, the bacterial segregation machinery anchors a single chromosome at the hyphal tip. Through chromosomal anchorage, segregation proteins facilitate chromosome targeting to the newly formed germ tubes or branches. Thus, being adapted for apical growth, in Streptomyces hyphae the bacterial segregation machinery imposes a chromosome distribution that is reminiscent of nuclear distribution in apically growing eukaryotic cells such as filamentous fungi.
Collapse
Affiliation(s)
| | | | | | - Emma Tilley
- Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Jolanta Zakrzewska-Czerwińska
- Faculty of Biotechnology, University of Wroclaw, Poland
- Institute of Immunology and Experimental Therapy, Wroclaw, Poland
| | - Paul Herron
- Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Dagmara Jakimowicz
- Faculty of Biotechnology, University of Wroclaw, Poland
- Institute of Immunology and Experimental Therapy, Wroclaw, Poland
- * E-mail:
| |
Collapse
|
33
|
Duan Y, Huey JD, Herman JK. The DnaA inhibitor SirA acts in the same pathway as Soj (ParA) to facilitateoriCsegregation duringBacillus subtilissporulation. Mol Microbiol 2016; 102:530-544. [DOI: 10.1111/mmi.13477] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2016] [Indexed: 01/18/2023]
Affiliation(s)
- Yi Duan
- Department of Biochemistry and Biophysics; Texas A&M University; College Station TX USA
| | - Jack D. Huey
- Department of Biochemistry and Biophysics; Texas A&M University; College Station TX USA
| | - Jennifer K. Herman
- Department of Biochemistry and Biophysics; Texas A&M University; College Station TX USA
| |
Collapse
|