1
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Barrows JM, Talavera-Figueroa BK, Payne IP, Smith EL, Goley ED. GTPase activity regulates FtsZ ring positioning in Caulobacter crescentus. Mol Biol Cell 2024; 35:ar97. [PMID: 38758654 PMCID: PMC11244171 DOI: 10.1091/mbc.e23-09-0365] [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: 09/13/2023] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/19/2024] Open
Abstract
Bacterial cell division is crucial for replication and requires careful coordination via proteins collectively called the divisome. The tubulin-like GTPase FtsZ is the master regulator of this process and serves to recruit downstream divisome proteins and regulate their activities. Upon assembling at mid-cell, FtsZ exhibits treadmilling motion driven by GTP binding and hydrolysis. Treadmilling is proposed to play roles in Z-ring condensation and in distribution and regulation of peptidoglycan (PG) cell wall enzymes. FtsZ polymer superstructure and dynamics are central to its function, yet their regulation is incompletely understood. We addressed these gaps in knowledge by evaluating the contribution of GTPase activity to FtsZ's function in vitro and in Caulobacter crescentus cells. We observed that a lethal mutation that abrogates FtsZ GTP hydrolysis impacts FtsZ dynamics and Z-ring positioning, but not constriction. Aberrant Z-ring positioning was due to insensitivity to the FtsZ regulator MipZ when GTPase activity is reduced. Z-ring mislocalization resulted in DNA damage, likely due to constriction over the nucleoid. Collectively, our results indicate that GTP hydrolysis serves primarily to position the Z-ring at mid-cell in Caulobacter. Proper Z-ring localization is required for effective coordination with chromosome segregation to prevent DNA damage and ensure successful cell division.
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Affiliation(s)
- Jordan M. Barrows
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | | | - Isaac P. Payne
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Erika L. Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Erin D. Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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2
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Santiago-Collazo G, Brown PJB, Randich AM. The divergent early divisome: is there a functional core? Trends Microbiol 2024; 32:231-240. [PMID: 37741788 DOI: 10.1016/j.tim.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/25/2023]
Abstract
The bacterial divisome is a complex nanomachine that drives cell division and separation. The essentiality of these processes leads to the assumption that proteins with core roles will be strictly conserved across all bacterial genomes. However, recent studies in diverse proteobacteria have revealed considerable variation in the early divisome compared with Escherichia coli. While some proteins are highly conserved, their specific functions and interacting partners vary. Meanwhile, different subphyla use clade-specific proteins with analogous functions. Thus, instead of focusing on gene conservation, we must also explore how key functions are maintained during early division by diverging protein networks. An enhanced awareness of these complex genetic networks will clarify the physical and evolutionary constraints of bacterial division.
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Affiliation(s)
- Gustavo Santiago-Collazo
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri-Columbia, Columbia, MO, USA
| | - Pamela J B Brown
- Division of Biological Sciences, College of Arts and Sciences, University of Missouri-Columbia, Columbia, MO, USA
| | - Amelia M Randich
- Department of Biology, College of Arts and Sciences, University of Scranton, Scranton, PA, USA.
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3
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Mahone CR, Payne IP, Lyu Z, McCausland JW, Barrows JM, Xiao J, Yang X, Goley ED. Integration of cell wall synthesis and chromosome segregation during cell division in Caulobacter. J Cell Biol 2024; 223:e202211026. [PMID: 38015166 PMCID: PMC10683668 DOI: 10.1083/jcb.202211026] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 10/17/2023] [Accepted: 11/10/2023] [Indexed: 11/29/2023] Open
Abstract
To divide, bacteria must synthesize their peptidoglycan (PG) cell wall, a protective meshwork that maintains cell shape. FtsZ, a tubulin homolog, dynamically assembles into a midcell band, recruiting division proteins, including the PG synthases FtsW and FtsI. FtsWI are activated to synthesize PG and drive constriction at the appropriate time and place. However, their activation pathway remains unresolved. In Caulobacter crescentus, FtsWI activity requires FzlA, an essential FtsZ-binding protein. Through time-lapse imaging and single-molecule tracking of Caulobacter FtsW and FzlA, we demonstrate that FzlA is a limiting constriction activation factor that signals to promote conversion of inactive FtsW to an active, slow-moving state. We find that FzlA interacts with the DNA translocase FtsK and place FtsK genetically in a pathway with FzlA and FtsWI. Misregulation of the FzlA-FtsK-FtsWI pathway leads to heightened DNA damage and cell death. We propose that FzlA integrates the FtsZ ring, chromosome segregation, and PG synthesis to ensure robust and timely constriction during Caulobacter division.
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Affiliation(s)
- Christopher R. Mahone
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Isaac P. Payne
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhixin Lyu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Joshua W. McCausland
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jordan M. Barrows
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xinxing Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Division of Life Sciences and Medicine, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Basic Medical Sciences, University of Science and Technology of China, Hefei, China
| | - Erin D. Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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4
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Cameron TA, Margolin W. Insights into the assembly and regulation of the bacterial divisome. Nat Rev Microbiol 2024; 22:33-45. [PMID: 37524757 PMCID: PMC11102604 DOI: 10.1038/s41579-023-00942-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2023] [Indexed: 08/02/2023]
Abstract
The ability to split one cell into two is fundamental to all life, and many bacteria can accomplish this feat several times per hour with high accuracy. Most bacteria call on an ancient homologue of tubulin, called FtsZ, to localize and organize the cell division machinery, the divisome, into a ring-like structure at the cell midpoint. The divisome includes numerous other proteins, often including an actin homologue (FtsA), that interact with each other at the cytoplasmic membrane. Once assembled, the protein complexes that comprise the dynamic divisome coordinate membrane constriction with synthesis of a division septum, but only after overcoming checkpoints mediated by specialized protein-protein interactions. In this Review, we summarize the most recent evidence showing how the divisome proteins of Escherichia coli assemble at the cell midpoint, interact with each other and regulate activation of septum synthesis. We also briefly discuss the potential of divisome proteins as novel antibiotic targets.
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Affiliation(s)
- Todd A Cameron
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, USA.
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5
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Naha A, Haeusser DP, Margolin W. Anchors: A way for FtsZ filaments to stay membrane bound. Mol Microbiol 2023; 120:525-538. [PMID: 37503768 PMCID: PMC10593102 DOI: 10.1111/mmi.15067] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 07/29/2023]
Abstract
Most bacteria use the tubulin homolog FtsZ to organize their cell division. FtsZ polymers initially assemble into mobile complexes that circle around a ring-like structure at the cell midpoint, followed by the recruitment of other proteins that will constrict the cytoplasmic membrane and synthesize septal peptidoglycan to divide the cell. Despite the need for FtsZ polymers to associate with the membrane, FtsZ lacks intrinsic membrane binding ability. Consequently, FtsZ polymers have evolved to interact with the membrane through adaptor proteins that both bind FtsZ and the membrane. Here, we discuss recent progress in understanding the functions of these FtsZ membrane tethers. Some, such as FtsA and SepF, are widely conserved and assemble into varied oligomeric structures bound to the membrane through an amphipathic helix. Other less-conserved proteins, such as EzrA and ZipA, have transmembrane domains, make extended structures, and seem to bind to FtsZ through two separate interactions. This review emphasizes that most FtsZs use multiple membrane tethers with overlapping functions, which not only attach FtsZ polymers to the membrane but also organize them in specific higher-order structures that can optimize cell division activity. We discuss gaps in our knowledge of these concepts and how future studies can address them.
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Affiliation(s)
- Arindam Naha
- Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, TX 77030, USA
| | - Daniel P. Haeusser
- Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, TX 77030, USA
- Department of Biology, Canisius College, Buffalo, NY 14208, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, TX 77030, USA
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6
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Alberge F, Lakey BD, Schaub RE, Dohnalkova AC, Lemmer KC, Dillard JP, Noguera DR, Donohue TJ. A previously uncharacterized divisome-associated lipoprotein, DalA, is needed for normal cell division in Rhodobacterales. mBio 2023; 14:e0120323. [PMID: 37389444 PMCID: PMC10470522 DOI: 10.1128/mbio.01203-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 07/01/2023] Open
Abstract
The bacterial cell envelope is a key subcellular compartment with important roles in antibiotic resistance, nutrient acquisition, and cell morphology. We seek to gain a better understanding of proteins that contribute to the function of the cell envelope in Alphaproteobacteria. Using Rhodobacter sphaeroides, we show that a previously uncharacterized protein, RSP_1200, is an outer membrane (OM) lipoprotein that non-covalently binds peptidoglycan (PG). Using a fluorescently tagged version of this protein, we find that RSP_1200 undergoes a dynamic repositioning during the cell cycle and is enriched at the septum during cell division. We show that the position of RSP_1200 mirrors the location of FtsZ rings, leading us to propose that RSP_1200 is a newly identified component of the R. sphaeroides' divisome. Additional support for this hypothesis includes the co-precipitation of RSP_1200 with FtsZ, the Pal protein, and several predicted PG L,D-transpeptidases. We also find that a ∆RSP_1200 mutation leads to defects in cell division, sensitivity to PG-active antibiotics, and results in the formation of OM protrusions at the septum during cell division. Based on these results, we propose to name RSP_1200 DalA (for division-associated lipoprotein A) and postulate that DalA serves as a scaffold to position or modulate the activity of PG transpeptidases that are needed to form envelope invaginations during cell division. We find that DalA homologs are present in members of the Rhodobacterales order within Alphaproteobacteria. Therefore, we propose that further analysis of this and related proteins will increase our understanding of the macromolecular machinery and proteins that participate in cell division in Gram-negative bacteria. IMPORTANCE Multi-protein complexes of the bacterial cell envelope orchestrate key processes like growth, division, biofilm formation, antimicrobial resistance, and production of valuable compounds. The subunits of these protein complexes are well studied in some bacteria, and differences in their composition and function are linked to variations in cell envelope composition, shape, and proliferation. However, some envelope protein complex subunits have no known homologs across the bacterial phylogeny. We find that Rhodobacter sphaeroides RSP_1200 is a newly identified lipoprotein (DalA) and that loss of this protein causes defects in cell division and changes the sensitivity to compounds, affecting cell envelope synthesis and function. We find that DalA forms a complex with proteins needed for cell division, binds the cell envelope polymer peptidoglycan, and colocalizes with enzymes involved in the assembly of this macromolecule. The analysis of DalA provides new information on the cell division machinery in this and possibly other Alphaproteobacteria.
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Affiliation(s)
- François Alberge
- />Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Bryan D. Lakey
- />Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ryan E. Schaub
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alice C. Dohnalkova
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, USA
| | | | - Joseph P. Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Daniel R. Noguera
- />Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Timothy J. Donohue
- />Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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7
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Shinn MK, Cohan MC, Bullock JL, Ruff KM, Levin PA, Pappu RV. Connecting sequence features within the disordered C-terminal linker of Bacillus subtilis FtsZ to functions and bacterial cell division. Proc Natl Acad Sci U S A 2022; 119:e2211178119. [PMID: 36215496 PMCID: PMC9586301 DOI: 10.1073/pnas.2211178119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/20/2022] [Indexed: 11/21/2022] Open
Abstract
Intrinsically disordered regions (IDRs) can function as autoregulators of folded enzymes to which they are tethered. One example is the bacterial cell division protein FtsZ. This includes a folded core and a C-terminal tail (CTT) that encompasses a poorly conserved, disordered C-terminal linker (CTL) and a well-conserved 17-residue C-terminal peptide (CT17). Sites for GTPase activity of FtsZs are formed at the interface between GTP binding sites and T7 loops on cores of adjacent subunits within dimers. Here, we explore the basis of autoregulatory functions of the CTT in Bacillus subtilis FtsZ (Bs-FtsZ). Molecular simulations show that the CT17 of Bs-FtsZ makes statistically significant CTL-mediated contacts with the T7 loop. Statistical coupling analysis of more than 1,000 sequences from FtsZ orthologs reveals clear covariation of the T7 loop and the CT17 with most of the core domain, whereas the CTL is under independent selection. Despite this, we discover the conservation of nonrandom sequence patterns within CTLs across orthologs. To test how the nonrandom patterns of CTLs mediate CTT-core interactions and modulate FtsZ functionalities, we designed Bs-FtsZ variants by altering the patterning of oppositely charged residues within the CTL. Such alterations disrupt the core-CTT interactions, lead to anomalous assembly and inefficient GTP hydrolysis in vitro and protein degradation, aberrant assembly, and disruption of cell division in vivo. Our findings suggest that viable CTLs in FtsZs are likely to be IDRs that encompass nonrandom, functionally relevant sequence patterns that also preserve three-way covariation of the CT17, the T7 loop, and core domain.
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Affiliation(s)
- Min Kyung Shinn
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Megan C. Cohan
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Jessie L. Bullock
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130
| | - Kiersten M. Ruff
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Petra A. Levin
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130
| | - Rohit V. Pappu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
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8
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Escherichia coli minicells with targeted enzymes as bioreactors for producing toxic compounds. Metab Eng 2022; 73:214-224. [PMID: 35970507 DOI: 10.1016/j.ymben.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/05/2022] [Accepted: 08/06/2022] [Indexed: 11/20/2022]
Abstract
Formed by aberrant cell division, minicells possess functional metabolism despite their inability to grow and divide. Minicells exhibit not only superior stability when compared with bacterial cells but also exceptional tolerance-characteristics that are essential for a de novo bioreactor platform. Accordingly, we engineered minicells to accumulate protein, ensuring sufficient production capability. When tested with chemicals regarded as toxic against cells, the engineered minicells produced titers of C6-C10 alcohols and esters, far surpassing the corresponding production from bacterial cells. Additionally, microbial autoinducer production that is limited in expanding bacterial population was conducted in the minicells. Because bacterial population growth was nonexistent, the minicells produced autoinducers in constant amounts, which allowed precise control of the bacterial population having autoinducer-responsive gene circuits. When bacterial population growth was nonexistent, the minicells produced autoinducers in constant amounts, which allowed precise control of the bacterial population having autoinducer-based gene circuits with the minicells. This study demonstrates the potential of minicells as bioreactors suitable for products with known limitations in microbial production, thus providing new possibilities for bioreactor engineering.
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9
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Zhang C, Liu W, Deng J, Ma S, Chang Z, Yang J. Structural Insights into the Interaction between Bacillus subtilis SepF Assembly and FtsZ by Solid-State NMR Spectroscopy. J Phys Chem B 2022; 126:5219-5230. [PMID: 35799411 DOI: 10.1021/acs.jpcb.2c02810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In many species of Gram-positive bacteria, SepF participated in the membrane tethering of FtsZ Z-ring during bacteria division. However, atomic-level details of interaction between SepF and FtsZ in an assembled state are lacking. Here, by combining solid-state NMR (SSNMR) with biochemical analyses, the interaction of Bacillus subtilis SepF and the C-terminal domain (CTD) of FtsZ was investigated. We obtained near complete chemical shift assignments of SepF and determined the structural model of the SepF monomer. Interaction with FtsZ-CTD caused further packing of SepF rings, and SSNMR experiments revealed the affected residues locating at α1, α2, β3, and β4 of SepF. Solution NMR experiments of dimeric SepF constructed by point mutation strategy proved a prerequisite role of α-α interface formation in SepF for FtsZ binding. Overall, our results provide structural insights into the mechanisms of SepF-FtsZ interaction for better understanding the function of SepF in bacteria.
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Affiliation(s)
- Chang Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.,National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Wenjing Liu
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China.,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jing Deng
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Shaojie Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.,National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Ziwei Chang
- National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Jun Yang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.,National Center for Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
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10
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Ramos-León F, Ramamurthi K. Cytoskeletal proteins: Lessons learned from bacteria. Phys Biol 2022; 19. [PMID: 35081523 DOI: 10.1088/1478-3975/ac4ef0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/26/2022] [Indexed: 11/11/2022]
Abstract
Cytoskeletal proteins are classified as a group that is defined functionally, whose members are capable of polymerizing into higher order structures, either dynamically or statically, to perform structural roles during a variety of cellular processes. In eukaryotes, the most well-studied cytoskeletal proteins are actin, tubulin, and intermediate filaments, and are essential for cell shape and movement, chromosome segregation, and intracellular cargo transport. Prokaryotes often harbor homologs of these proteins, but in bacterial cells, these homologs are usually not employed in roles that can be strictly defined as "cytoskeletal". However, several bacteria encode other proteins capable of polymerizing which, although they do not appear to have a eukaryotic counterpart, nonetheless appear to perform a more traditional "cytoskeletal" function. In this review, we discuss recent reports that cover the structure and functions of prokaryotic proteins that are broadly termed as cytoskeletal, either by sequence homology or by function, to highlight how the enzymatic properties of traditionally studied cytoskeletal proteins may be used for other types of cellular functions; and to demonstrate how truly "cytoskeletal" functions may be performed by uniquely bacterial proteins that do not display homology to eukaryotic proteins.
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Affiliation(s)
- Félix Ramos-León
- National Institutes of Health, 37 Convent Dr., Bldg 37, Room 5132, Bethesda, Maryland, 20892, UNITED STATES
| | - Kumaran Ramamurthi
- Laboratory of Molecular Biology, National Cancer Institute, 37 Convent Dr, Bldg 37, Room 5132, Bethesda, Maryland, 20892, UNITED STATES
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11
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The Chaperonin GroESL Facilitates Caulobacter crescentus Cell Division by Supporting the Functions of the Z-Ring Regulators FtsA and FzlA. mBio 2021; 12:mBio.03564-20. [PMID: 33947758 PMCID: PMC8262945 DOI: 10.1128/mbio.03564-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The highly conserved chaperonin GroESL performs a crucial role in protein folding; however, the essential cellular pathways that rely on this chaperone are underexplored. Loss of GroESL leads to severe septation defects in diverse bacteria, suggesting the folding function of GroESL may be integrated with the bacterial cell cycle at the point of cell division. Here, we describe new connections between GroESL and the bacterial cell cycle using the model organism Caulobacter crescentus. Using a proteomics approach, we identify candidate GroESL client proteins that become insoluble or are degraded specifically when GroESL folding is insufficient, revealing several essential proteins that participate in cell division and peptidoglycan biosynthesis. We demonstrate that other cell cycle events, such as DNA replication and chromosome segregation, are able to continue when GroESL folding is insufficient. We further find that deficiency of two FtsZ-interacting proteins, the bacterial actin homologue FtsA and the constriction regulator FzlA, mediate the GroESL-dependent block in cell division. Our data show that sufficient GroESL is required to maintain normal dynamics of the FtsZ scaffold and divisome functionality in C. crescentus. In addition to supporting divisome function, we show that GroESL is required to maintain the flow of peptidoglycan precursors into the growing cell wall. Linking a chaperone to cell division may be a conserved way to coordinate environmental and internal cues that signal when it is safe to divide.
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12
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Barrows JM, Goley ED. FtsZ dynamics in bacterial division: What, how, and why? Curr Opin Cell Biol 2021; 68:163-172. [PMID: 33220539 PMCID: PMC7925355 DOI: 10.1016/j.ceb.2020.10.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/19/2020] [Accepted: 10/21/2020] [Indexed: 01/06/2023]
Abstract
Bacterial cell division is orchestrated by the divisome, a protein complex centered on the tubulin homolog FtsZ. FtsZ polymerizes into a dynamic ring that defines the division site, recruits downstream proteins, and directs peptidoglycan synthesis to drive constriction. Recent studies have documented treadmilling of FtsZ polymer clusters both in cells and in vitro. Emerging evidence suggests that FtsZ dynamics are regulated largely by intrinsic properties of FtsZ itself and by the membrane anchoring protein FtsA. Although FtsZ dynamics are broadly required for Z-ring assembly, their role(s) during constriction may vary among bacterial species. These recent advances set the stage for future studies to investigate how FtsZ dynamics are physically and/or functionally coupled to peptidoglycan metabolic enzymes to direct efficient division.
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Affiliation(s)
- Jordan M Barrows
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Erin D Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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13
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Fu Y, Jia Y, Fan J, Yu C, Yu C, Shen C. Induction of Escherichia coli O157:H7 into a viable but non-culturable state by high temperature and its resuscitation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:568-577. [PMID: 32783384 DOI: 10.1111/1758-2229.12877] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/09/2020] [Indexed: 06/11/2023]
Abstract
Escherichia coli O157:H7, a causative agent of haemolytic uremic syndrome, can enter into a viable but non-culturable (VBNC) state in response to harsh stress. Bacteria in this state can retain membrane integrity, metabolic activity and virulence expression, which may present health risks. However, virulence expression and resuscitation ability of the VBNC state are not well understood. Here, we induced E. coli O157:H7 into a VBNC state by high temperature, which is commonly used to prevent the proliferation of pathogens in process of soil solarization, composting and anaerobic digestion of organic wastes. The virulence genes were highly expressed in the VBNC state and resuscitated daughter cells. The resuscitation of VBNC cells occurred after the removal of heat stress in Luria-Bertani medium. In addition, E. coli O157: H7 cells can leave the VBNC state and resuscitate with the clearance of protein aggregates. Notably, with the accumulation of protein aggregation and increased levels of reactive oxygen species, cells lost their ability to resuscitate. The results of this study not only can facilitate a better understanding of the health risks associated with the VBNC state but also have the potential to provide a theoretical basis for thermal disinfection processing.
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Affiliation(s)
- Yulong Fu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yangyang Jia
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jiahui Fan
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Chunna Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Chungui Yu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China
- Zhejiang Provincial Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, 310058, China
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Abstract
Bacterial cell division is initiated by the midcell assembly of polymers of the tubulin-like GTPase FtsZ. The FtsZ ring (Z-ring) is a discontinuous structure made of dynamic patches of FtsZ that undergo treadmilling motion. Roughly a dozen additional essential proteins are recruited to the division site by the dynamic Z-ring scaffold and subsequently activate cell wall synthesis to drive cell envelope constriction during division. In this Cell Science at a Glance article and the accompanying poster, we summarize our understanding of the assembly and activation of the bacterial cell division machinery. We introduce polymerization properties of FtsZ and discuss our current knowledge of divisome assembly and activation. We further highlight the intimate relationship between the structure and dynamics of FtsZ and the movement and activity of cell wall synthases at the division site, before concluding with a perspective on the most important open questions on bacterial cell division.
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Affiliation(s)
- Christopher R Mahone
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Erin D Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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