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Masser EA, Burby PE, Hawkins WD, Gustafson BR, Lenhart JS, Simmons LA. DNA damage checkpoint activation affects peptidoglycan synthesis and late divisome components in Bacillus subtilis. Mol Microbiol 2021; 116:707-722. [PMID: 34097787 DOI: 10.1111/mmi.14765] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 11/28/2022]
Abstract
During normal DNA replication, all cells encounter damage to their genetic material. As a result, organisms have developed response pathways that provide time for the cell to complete DNA repair before cell division occurs. In Bacillus subtilis, it is well established that the SOS-induced cell division inhibitor YneA blocks cell division after genotoxic stress; however, it remains unclear how YneA enforces the checkpoint. Here, we identify mutations that disrupt YneA activity and mutations that are refractory to the YneA-induced checkpoint. We find that YneA C-terminal truncation mutants and point mutants in or near the LysM peptidoglycan binding domain render YneA incapable of checkpoint enforcement. In addition, we develop a genetic method which isolated mutations in the ftsW gene that completely bypassed checkpoint enforcement while also finding that YneA interacts with late divisome components FtsL, Pbp2b, and Pbp1. Characterization of an FtsW variant resulted in considerably shorter cells during the DNA damage response indicative of hyperactive initiation of cell division and bypass of the YneA-enforced DNA damage checkpoint. With our results, we present a model where YneA inhibits septal cell wall synthesis by binding peptidoglycan and interfering with interaction between late arriving divisome components causing DNA damage checkpoint activation.
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Affiliation(s)
- Emily A Masser
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Peter E Burby
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Wayne D Hawkins
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Brooke R Gustafson
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Justin S Lenhart
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Lyle A Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
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2
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Hicks A, Escobar CA, Cross TA, Zhou HX. Fuzzy Association of an Intrinsically Disordered Protein with Acidic Membranes. JACS AU 2021; 1:66-78. [PMID: 33554215 PMCID: PMC7851954 DOI: 10.1021/jacsau.0c00039] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Indexed: 05/03/2023]
Abstract
Many physiological and pathophysiological processes, including Mycobacterium tuberculosis (Mtb) cell division, may involve fuzzy membrane association by proteins via intrinsically disordered regions. The fuzziness is extreme when the conformation and pose of the bound protein and the composition of the proximal lipids are all highly dynamic. Here, we tackled the challenge in characterizing the extreme fuzzy membrane association of the disordered, cytoplasmic N-terminal region (NT) of ChiZ, an Mtb divisome protein, by combining solution and solid-state NMR spectroscopy and molecular dynamics simulations. While membrane-associated NT does not gain any secondary structure, its interactions with lipids are not random, but formed largely by Arg residues predominantly in the second, conserved half of the NT sequence. As NT frolics on the membrane, lipids quickly redistribute, with acidic lipids, relative to zwitterionic lipids, preferentially taking up Arg-proximal positions. The asymmetric engagement of NT arises partly from competition between acidic lipids and acidic residues, all in the first half of NT, for Arg interactions. This asymmetry is accentuated by membrane insertion of the downstream transmembrane helix. This type of semispecific molecular recognition may be a general mechanism by which disordered proteins target membranes.
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Affiliation(s)
- Alan Hicks
- Institute
of Molecular Biophysics, Department of Physics, and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- Department
of Chemistry and Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Cristian A. Escobar
- Institute
of Molecular Biophysics, Department of Physics, and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Timothy A. Cross
- Institute
of Molecular Biophysics, Department of Physics, and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National
High Magnetic Field Laboratory, Florida
State University, Tallahassee, Florida 32310, United States
| | - Huan-Xiang Zhou
- Department
of Chemistry and Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, United States
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3
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Hicks A, Escobar CA, Cross TA, Zhou HX. Sequence-Dependent Correlated Segments in the Intrinsically Disordered Region of ChiZ. Biomolecules 2020; 10:biom10060946. [PMID: 32585849 PMCID: PMC7355643 DOI: 10.3390/biom10060946] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 12/12/2022] Open
Abstract
How sequences of intrinsically disordered proteins (IDPs) code for their conformational dynamics is poorly understood. Here, we combined NMR spectroscopy, small-angle X-ray scattering (SAXS), and molecular dynamics (MD) simulations to characterize the conformations and dynamics of ChiZ1-64. MD simulations, first validated by SAXS and secondary chemical shift data, found scant α-helices or β-strands but a considerable propensity for polyproline II (PPII) torsion angles. Importantly, several blocks of residues (e.g., 11–29) emerge as “correlated segments”, identified by their frequent formation of PPII stretches, salt bridges, cation-π interactions, and sidechain-backbone hydrogen bonds. NMR relaxation experiments showed non-uniform transverse relaxation rates (R2s) and nuclear Overhauser enhancements (NOEs) along the sequence (e.g., high R2s and NOEs for residues 11–14 and 23–28). MD simulations further revealed that the extent of segmental correlation is sequence-dependent; segments where internal interactions are more prevalent manifest elevated “collective” motions on the 5–10 ns timescale and suppressed local motions on the sub-ns timescale. Amide proton exchange rates provides corroboration, with residues in the most correlated segment exhibiting the highest protection factors. We propose the correlated segment as a defining feature for the conformations and dynamics of IDPs.
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Affiliation(s)
- Alan Hicks
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; (A.H.); (C.A.E.)
- Department of Physics, Florida State University, Tallahassee, FL 32306, USA
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Cristian A. Escobar
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; (A.H.); (C.A.E.)
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Timothy A. Cross
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; (A.H.); (C.A.E.)
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
- Correspondence: (T.A.C.); (H.-X.Z.)
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
- Correspondence: (T.A.C.); (H.-X.Z.)
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4
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Bojer MS, Frees D, Ingmer H. SosA in Staphylococci: an addition to the paradigm of membrane-localized, SOS-induced cell division inhibition in bacteria. Curr Genet 2020; 66:495-499. [PMID: 31925496 DOI: 10.1007/s00294-019-01052-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 12/28/2019] [Accepted: 12/31/2019] [Indexed: 12/19/2022]
Abstract
In all living organisms, genome replication and cell division must be coordinated to produce viable offspring. In the event of DNA damage, bacterial cells employ the SOS response to simultaneously express damage repair systems and halt cell division. Extensive characterization of SOS-controlled cell division inhibition in Escherichia coli has laid the ground for a long-standing paradigm where the cytosolic SulA protein inhibits polymerization of the central division protein, FtsZ, and thereby prevents recruitment of the division machinery at the future division site. Within the last decade, it has become clear that another, likely more general, paradigm exists, at least within the broad group of Gram-positive bacterial species, namely membrane-localized, SOS-induced cell division inhibition. We recently identified such an inhibitor in Staphylococci, SosA, and established a model for SosA-mediated cell division inhibition in Staphylococcus aureus in response to DNA damage. SosA arrests cell division subsequent to the septal localization of FtsZ and later membrane-bound division proteins, while preventing progression to septum closure, leading to synchronization of cells at this particular stage. A membrane-associated protease, CtpA negatively regulates SosA activity and likely allows growth to resume once conditions are favorable. Here, we provide a brief summary of our findings in the context of what already is known for other membrane cell division inhibitors and we emphasize how poorly characterized these intriguing processes are mechanistically. Furthermore, we put some perspective on the relevance of our findings and future developments within the field.
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Affiliation(s)
- Martin S Bojer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dorte Frees
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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5
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Bojer MS, Wacnik K, Kjelgaard P, Gallay C, Bottomley AL, Cohn MT, Lindahl G, Frees D, Veening JW, Foster SJ, Ingmer H. SosA inhibits cell division in Staphylococcus aureus in response to DNA damage. Mol Microbiol 2019; 112:1116-1130. [PMID: 31290194 PMCID: PMC6851548 DOI: 10.1111/mmi.14350] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2019] [Indexed: 01/10/2023]
Abstract
Inhibition of cell division is critical for viability under DNA‐damaging conditions. DNA damage induces the SOS response that in bacteria inhibits cell division while repairs are being made. In coccoids, such as the human pathogen, Staphylococcus aureus, this process remains poorly studied. Here, we identify SosA as the staphylococcal SOS‐induced cell division inhibitor. Overproduction of SosA inhibits cell division, while sosA inactivation sensitizes cells to genotoxic stress. SosA is a small, predicted membrane protein with an extracellular C‐terminal domain in which point mutation of residues that are conserved in staphylococci and major truncations abolished the inhibitory activity. In contrast, a minor truncation led to SosA accumulation and a strong cell division inhibitory activity, phenotypically similar to expression of wild‐type SosA in a CtpA membrane protease mutant. This suggests that the extracellular C‐terminus of SosA is required both for cell division inhibition and for turnover of the protein. Microscopy analysis revealed that SosA halts cell division and synchronizes the cell population at a point where division proteins such as FtsZ and EzrA are localized at midcell, and the septum formation is initiated but unable to progress to closure. Thus, our findings show that SosA is central in cell division regulation in staphylococci.
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Affiliation(s)
- Martin S Bojer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Centre for Bacterial Stress Response and Persistence, University of Copenhagen, Copenhagen, Denmark
| | - Katarzyna Wacnik
- Department of Molecular Biology and Biotechnology, The Krebs Institute, University of Sheffield, Sheffield, UK
| | - Peter Kjelgaard
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Clement Gallay
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Amy L Bottomley
- Department of Molecular Biology and Biotechnology, The Krebs Institute, University of Sheffield, Sheffield, UK
| | - Marianne T Cohn
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gunnar Lindahl
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dorte Frees
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Simon J Foster
- Department of Molecular Biology and Biotechnology, The Krebs Institute, University of Sheffield, Sheffield, UK
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Centre for Bacterial Stress Response and Persistence, University of Copenhagen, Copenhagen, Denmark
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6
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Abstract
How do mycobacteria divide? Cell division has been studied extensively in the model rod-shaped bacteria Escherichia coli and Bacillus subtilis, but much less is understood about cell division in mycobacteria, a genus that includes the major human pathogens M. tuberculosis and M. leprae. In general, bacterial cell division requires the concerted effort of many proteins in both space and time to elongate the cell, replicate and segregate the chromosome, and construct and destruct the septum - processes which result in the creation of two new daughter cells. Here, we describe these distinct stages of cell division in B. subtilis and follow with the current knowledge in mycobacteria. As will become apparent, there are many differences between mycobacteria and B. subtilis in terms of both the broad outline of cell division and the molecular details. So, while the fundamental challenge of spatially and temporally organizing cell division is shared between these rod-shaped bacteria, they have solved these challenges in often vastly different ways.
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7
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Abstract
Actinobacteria is a group of diverse bacteria. Most species in this class of bacteria are filamentous aerobes found in soil, including the genus Streptomyces perhaps best known for their fascinating capabilities of producing antibiotics. These bacteria typically have a Gram-positive cell envelope, comprised of a plasma membrane and a thick peptidoglycan layer. However, there is a notable exception of the Corynebacteriales order, which has evolved a unique type of outer membrane likely as a consequence of convergent evolution. In this chapter, we will focus on the unique cell envelope of this order. This cell envelope features the peptidoglycan layer that is covalently modified by an additional layer of arabinogalactan . Furthermore, the arabinogalactan layer provides the platform for the covalent attachment of mycolic acids , some of the longest natural fatty acids that can contain ~100 carbon atoms per molecule. Mycolic acids are thought to be the main component of the outer membrane, which is composed of many additional lipids including trehalose dimycolate, also known as the cord factor. Importantly, a subset of bacteria in the Corynebacteriales order are pathogens of human and domestic animals, including Mycobacterium tuberculosis. The surface coat of these pathogens are the first point of contact with the host immune system, and we now know a number of host receptors specific to molecular patterns exposed on the pathogen's surface, highlighting the importance of understanding how the cell envelope of Actinobacteria is structured and constructed. This chapter describes the main structural and biosynthetic features of major components found in the actinobacterial cell envelopes and highlights the key differences between them.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA.
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8
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Puffal J, García-Heredia A, Rahlwes KC, Siegrist MS, Morita YS. Spatial control of cell envelope biosynthesis in mycobacteria. Pathog Dis 2018; 76:4953754. [DOI: 10.1093/femspd/fty027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/25/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Julia Puffal
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Alam García-Heredia
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
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9
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Escobar CA, Cross TA. False positives in using the zymogram assay for identification of peptidoglycan hydrolases. Anal Biochem 2017; 543:162-166. [PMID: 29246750 DOI: 10.1016/j.ab.2017.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/07/2017] [Accepted: 12/11/2017] [Indexed: 11/17/2022]
Abstract
Zymogram assays have been used extensively to identify novel peptidoglycan hydrolases. In this study it is reported that the zymogram is susceptible to false positive results when highly positively charged proteins are assayed. As an example, we report on the case of the ChiZ membrane protein from the Mycobacterium tuberculosis divisome, which previously was described as a peptidoglycan hydrolase. Even though the full length ChiZ protein was able to produce positive assay results, other direct methods for measuring peptidoglycan hydrolysis do not provide convincing evidence that ChiZ has peptidoglycan hydrolysis activity. We show that the false positive result is produced by the highly positively charged N-terminal region of ChiZ. Thus, we developed a zymogram control that can be used to identify false positives results. This control assay lacks the refolding step in the normal zymogram assay. For lysozyme the control assay shows no activity, while the N-terminal region of ChiZ shows a false positive result. Given the limitations of the zymogram assay to reliably identify peptidoglycan hydrolases, we recommend using the zymogram control assay together with other methods to evaluate possible peptidoglycan hydrolysis activity.
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Affiliation(s)
- Cristian A Escobar
- Institute of Molecular Biophysics, and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 USA
| | - Timothy A Cross
- Department of Chemistry and Biochemistry, Institute of Molecular Biophysics, and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 USA.
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10
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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.
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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;
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11
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Kirsebom LA, Dasgupta S, Fredrik Pettersson BM. Pleiomorphism in Mycobacterium. ADVANCES IN APPLIED MICROBIOLOGY 2016; 80:81-112. [PMID: 22794145 DOI: 10.1016/b978-0-12-394381-1.00004-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Morphological variants in mycobacterial cultures under different growth conditions, including aging of the culture, have been shown to include fibrous aggregates, biofilms, coccoids, and spores. Here we discuss the diversity in shape and size changes demonstrated by bacterial cells with special reference to pleiomorphism observed in Mycobacterium spp. in response to nutritional and other environmental stresses. Inherent asymmetry in cell division and compartmentalization of cell interior under different growth conditions might contribute toward the observed pleiomorphism in mycobacteria. The regulatory genes comprising the bacterial signaling pathway responsible for initiating morphogenesis are speculated upon from bioinformatic identifications of genes for known sensors, kinases, and phosphatases existing in mycobacterial genomes as well as on the basis of what is known in other bacteria.
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12
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Abstract
The complex cell envelope is a hallmark of mycobacteria and is anchored by the peptidoglycan layer, which is similar to that of Escherichia coli and a number of other bacteria but with modifications to the monomeric units and other structural complexities that are likely related to a role for the peptidoglycan in stabilizing the mycolyl-arabinogalactan-peptidoglycan complex (MAPc). In this article, we will review the genetics of several aspects of peptidoglycan biosynthesis in mycobacteria, including the production of monomeric precursors in the cytoplasm, assembly of the monomers into the mature wall, cell wall turnover, and cell division. Finally, we will touch upon the resistance of mycobacteria to β-lactam antibiotics, an important class of drugs that, until recently, have not been extensively exploited as potential antimycobacterial agents. We will also note areas of research where there are still unanswered questions.
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13
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Gupta S, Banerjee SK, Chatterjee A, Sharma AK, Kundu M, Basu J. Essential protein SepF of mycobacteria interacts with FtsZ and MurG to regulate cell growth and division. MICROBIOLOGY-SGM 2015; 161:1627-1638. [PMID: 25971440 DOI: 10.1099/mic.0.000108] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Coordinated bacterial cell septation and cell wall biosynthesis require formation of protein complexes at the sites of division and elongation, in a temporally controlled manner. The protein players in these complexes remain incompletely understood in mycobacteria. Using in vitro and in vivo assays, we showed that Rv2147c (or SepF) of Mycobacterium tuberculosis interacts with the principal driver of cytokinesis, FtsZ. SepF also interacts with itself both in vitro and in vivo. Amino acid residues 189A, 190K and 215F are required for FtsZ-SepF interaction, and are conserved across Gram-positive bacteria. Using Mycobacterium smegmatis as a surrogate system, we confirmed that sepFMSMEG is essential. Knockdown of SepF led to cell elongation, defective growth and failure of FtsZ to localize to the site of division, suggesting that SepF assists FtsZ localization at the site of division. Furthermore, SepF interacted with MurG, a peptidoglycan-synthesizing enzyme, both in vitro and in vivo, suggesting that SepF could serve as a link between cell division and peptidoglycan synthesis. SepF emerges as a newly identified essential component of the cell division complex in mycobacteria.
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Affiliation(s)
- Shamba Gupta
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Srijon Kaushik Banerjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Ayan Chatterjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Arun Kumar Sharma
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
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14
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Sharma AK, Chatterjee A, Gupta S, Banerjee R, Mandal S, Mukhopadhyay J, Basu J, Kundu M. MtrA, an essential response regulator of the MtrAB two-component system, regulates the transcription of resuscitation-promoting factor B of Mycobacterium tuberculosis. MICROBIOLOGY-SGM 2015; 161:1271-81. [PMID: 25833257 DOI: 10.1099/mic.0.000087] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The resuscitation-promoting factors of Mycobacterium tuberculosis are hydrolytic enzymes, which are required for resuscitation of dormant cells. RpfB, a peptidoglycan remodelling enzyme similar to the lytic transglycosylase of Escherichia coli, is required for reactivation of M. tuberculosis from chronic infection in vivo, underscoring the need to understand its transcriptional regulation. Here, we identified the transcriptional and translational start points of rpfB, and suggested from rpf promoter-driven GFP expression and in vitro transcription assays that its transcription possibly occurs in a SigB-dependent manner. We further demonstrated that rpfB transcription is regulated by MtrA - the response regulator of the essential two-component system MtrAB. Association of MtrA with the rpfB promoter region in vivo was confirmed by chromatin immunoprecipitation analysis. Electrophoretic mobility shift assays (EMSAs) revealed a loose direct repeat sequence associated with MtrA binding. Binding of MtrA was enhanced upon phosphorylation. MtrA could be pulled down from lysates of M. tuberculosis using a biotinylated DNA fragment encompassing the MtrA-binding site on the rpfB promoter, confirming that MtrA binds to the rpfB promoter. Enhanced GFP fluorescence driven by the rpfB promoter, upon deletion of the MtrA-binding site, and repression of rpfB expression, upon overexpression of MtrA, suggested that MtrA functions as a repressor of rpfB transcription. This was corroborated by EMSAs showing diminished association of RNA polymerase (RNAP) with the rpfB promoter in the presence of MtrA. In vitro transcription assays confirmed that MtrA inhibits RNAP-driven rpfB transcription.
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Affiliation(s)
- Arun Kumar Sharma
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Ayan Chatterjee
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Shamba Gupta
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Rajdeep Banerjee
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Sukhendu Mandal
- 2Department of Biochemistry, Bose Institute, P-1/12 CIT Scheme VII M, Kolkata 700054, India
| | - Jayanta Mukhopadhyay
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Joyoti Basu
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manikuntala Kundu
- 1Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
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15
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Plocinski P, Martinez L, Sarva K, Plocinska R, Madiraju M, Rajagopalan M. Mycobacterium tuberculosis CwsA overproduction modulates cell division and cell wall synthesis. Tuberculosis (Edinb) 2014; 93 Suppl:S21-7. [PMID: 24388644 DOI: 10.1016/s1472-9792(13)70006-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We recently showed that two small membrane proteins of Mycobacterium tuberculosis, CwsA and CrgA, interact with each other, and that loss of CwsA in M. smegmatis is associated with defects in the cell division and cell wall synthesis processes. Here we show that CwsA overproduction also affected growth, cell division and cell shape of M. smegmatis and M. tuberculosis. CwsA overproduction in M. tuberculosis led to increased sensitivity to cefsulodin, a penicillin-binding protein (PBP) 1A/1B targeting beta (β) -lactam, but was unaffected by other β-lactams and vancomycin. A M. smegmatis cwsA overexpressing strain showed bulgy cells, increased fluorescent vancomycin staining and altered localization of Wag31-mCherry fusion protein. However, the levels of phosphorylated Wag31, important for optimal peptidoglycan synthesis and growth in mycobacteria, were not affected. Interestingly, CwsA overproduction in E. coli led to the formation of large rounded cells that eventually lysed whereas the overproduction of FtsZ along with CwsA reversed this phenotype. Together, our results emphasize that optimal levels of CwsA are required for regulated cell wall synthesis, hence maintenance of cell shape, and that CwsA likely interacts with and modulates the activities of other cell wall synthetic components including PBPs.
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Affiliation(s)
- P Plocinski
- Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA
| | - L Martinez
- Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA
| | - K Sarva
- Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA
| | - R Plocinska
- Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA
| | - M Madiraju
- Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA
| | - M Rajagopalan
- Biomedical Research, The University of Texas Health Science Center @ Tyler, Tyler, TX 75708, USA.
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Jani C, Tocheva EI, McAuley S, Craney A, Jensen GJ, Nodwell J. Streptomyces: a screening tool for bacterial cell division inhibitors. ACTA ACUST UNITED AC 2014; 20:275-84. [PMID: 25256667 DOI: 10.1177/1087057114551334] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cell division is essential for spore formation but not for viability in the filamentous streptomycetes bacteria. Failure to complete cell division instead blocks spore formation, a phenotype that can be visualized by the absence of gray (in Streptomyces coelicolor) and green (in Streptomyces venezuelae) spore-associated pigmentation. Despite the lack of essentiality, the streptomycetes divisome is similar to that of other prokaryotes. Therefore, the chemical inhibitors of sporulation in model streptomycetes may interfere with the cell division in rod-shaped bacteria as well. To test this, we investigated 196 compounds that inhibit sporulation in S. coelicolor. We show that 19 of these compounds cause filamentous growth in Bacillus subtilis, consistent with impaired cell division. One of the compounds is a DNA-damaging agent and inhibits cell division by activating the SOS response. The remaining 18 act independently of known stress responses and may therefore act on the divisome or on divisome positioning and stability. Three of the compounds (Fil-1, Fil-2, and Fil-3) confer distinct cell division defects on B. subtilis. They also block B. subtilis sporulation, which is mechanistically unrelated to the sporulation pathway of streptomycetes but is also dependent on the divisome. We discuss ways in which these differing phenotypes can be used in screens for cell division inhibitors.
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Affiliation(s)
- Charul Jani
- Department of Biochemistry and Biomedical Sciences, Michael DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, ON, Canada
| | - Elitza I Tocheva
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Scott McAuley
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Arryn Craney
- Department of Biochemistry and Biomedical Sciences, Michael DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, ON, Canada
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Justin Nodwell
- Department of Biochemistry and Biomedical Sciences, Michael DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, ON, Canada Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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Zafirlukast inhibits complexation of Lsr2 with DNA and growth of Mycobacterium tuberculosis. Antimicrob Agents Chemother 2013; 57:2134-40. [PMID: 23439641 DOI: 10.1128/aac.02407-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mycobacterial nucleoid-associated protein Lsr2 is a DNA-bridging protein that plays a role in condensation and structural organization of the genome and acts as a global repressor of gene transcription. Here we describe experiments demonstrating that zafirlukast inhibits the complexation between Lsr2 and DNA in vitro. Zafirlukast is shown to inhibit growth in two different species of mycobacteria tested but exhibits no growth inhibition of Escherichia coli. The Lsr2 inhibitory activity is reflected in vivo as determined by monitoring of transcription levels in Mycobacterium tuberculosis. These data suggest that zafirlukast inhibits Lsr2 function in vivo, promoting dysregulation of the expression of an array of genes typically bound by Lsr2 and hindering growth. Since zafirlukast likely operates by a mechanism distinct from current M. tuberculosis drugs and is currently used as a prophylactic treatment for asthma, it offers an intriguing lead for development of new treatments for tuberculosis.
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Mycobacterium tuberculosis CwsA interacts with CrgA and Wag31, and the CrgA-CwsA complex is involved in peptidoglycan synthesis and cell shape determination. J Bacteriol 2012; 194:6398-409. [PMID: 23002219 DOI: 10.1128/jb.01005-12] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial cell division and cell wall synthesis are highly coordinated processes involving multiple proteins. Here, we show that Rv0008c, a novel small membrane protein from Mycobacterium tuberculosis, localizes to the poles and on membranes and shows an overall punctate localization throughout the cell. Furthermore, Rv0008c interacts with two proteins, CrgA and Wag31, implicated in peptidoglycan (PG) synthesis in mycobacteria. Deletion of the Rv0008c homolog in M. smegmatis, MSMEG_0023, caused bulged cell poles, formation of rounded cells, and defects in polar localization of Wag31 and cell wall synthesis, with cell wall synthesis measured by the incorporation of the [(14)C]N-acetylglucosamine cell wall precursor. The M. smegmatis MSMEG_0023 crgA double mutant strain showed severe defects in growth, viability, cell wall synthesis, cell shape, and the localization of the FtsZ, FtsI, and Wag31 proteins. The double mutant strain also exhibited increased autolytic activity in the presence of detergents. Because CrgA and Wag31 proteins interact with FtsI individually, we believe that regulated cell wall synthesis and cell shape maintenance require the concerted actions of the CrgA, Rv0008c, FtsI, and Wag31 proteins. We propose that, together, CrgA and Rv0008c, renamed CwsA for cell wall synthesis and cell shape protein A, play crucial roles in septal and polar PG synthesis and help coordinate these processes with the FtsZ-ring assembly in mycobacteria.
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Endsley JJ, Actor JK. Texas Tuberculosis Research Symposium 2011: collaborative efforts within the State of Texas toward elimination of TB. Tuberculosis (Edinb) 2011; 91 Suppl 1:S1-2. [PMID: 22192869 DOI: 10.1016/j.tube.2011.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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