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Dergham Y, Le Coq D, Bridier A, Sanchez-Vizuete P, Jbara H, Deschamps J, Hamze K, Yoshida KI, Noirot-Gros MF, Briandet R. Bacillus subtilis NDmed, a model strain for biofilm genetic studies. Biofilm 2023; 6:100152. [PMID: 37694162 PMCID: PMC10485040 DOI: 10.1016/j.bioflm.2023.100152] [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: 03/27/2023] [Revised: 06/20/2023] [Accepted: 08/27/2023] [Indexed: 09/12/2023] Open
Abstract
The Bacillus subtilis strain NDmed was isolated from an endoscope washer-disinfector in a medical environment. NDmed can form complex macrocolonies with highly wrinkled architectural structures on solid medium. In static liquid culture, it produces thick pellicles at the interface with air as well as remarkable highly protruding ''beanstalk-like'' submerged biofilm structures at the solid surface. Since these mucoid submerged structures are hyper-resistant to biocides, NDmed has the ability to protect pathogens embedded in mixed-species biofilms by sheltering them from the action of these agents. Additionally, this non-domesticated and highly biofilm forming strain has the propensity of being genetically manipulated. Due to all these properties, the NDmed strain becomes a valuable model for the study of B. subtilis biofilms. This review focuses on several studies performed with NDmed that have highlighted the sophisticated genetic dynamics at play during B. subtilis biofilm formation. Further studies in project using modern molecular tools of advanced technologies with this strain, will allow to deepen our knowledge on the emerging properties of multicellular bacterial life.
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Affiliation(s)
- Yasmine Dergham
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
- Lebanese University, Faculty of Science, 1003 Beirut, Lebanon
| | - Dominique Le Coq
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
- Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Arnaud Bridier
- Fougères Laboratory, Antibiotics, Biocides, Residues and Resistance Unit, Anses, 35300, Fougères, France
| | - Pilar Sanchez-Vizuete
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Hadi Jbara
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Julien Deschamps
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | - Kassem Hamze
- Lebanese University, Faculty of Science, 1003 Beirut, Lebanon
| | - Ken-ichi Yoshida
- Department of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | | | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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2
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Masters EA, Muthukrishnan G, Ho L, Gill AL, de Mesy Bentley KL, Galloway CA, McGrath JL, Awad HA, Gill SR, Schwarz EM. Staphylococcus aureus Cell Wall Biosynthesis Modulates Bone Invasion and Osteomyelitis Pathogenesis. Front Microbiol 2021; 12:723498. [PMID: 34484165 PMCID: PMC8415456 DOI: 10.3389/fmicb.2021.723498] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/15/2021] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus invasion of the osteocyte lacuno-canalicular network (OLCN) is a novel mechanism of bacterial persistence and immune evasion in chronic osteomyelitis. Previous work highlighted S. aureus cell wall transpeptidase, penicillin binding protein 4 (PBP4), and surface adhesin, S. aureus surface protein C (SasC), as critical factors for bacterial deformation and propagation through nanopores in vitro, representative of the confined canaliculi in vivo. Given these findings, we hypothesized that cell wall synthesis machinery and surface adhesins enable durotaxis- and haptotaxis-guided invasion of the OLCN, respectively. Here, we investigated select S. aureus cell wall synthesis mutants (Δpbp3, Δatl, and ΔmreC) and surface adhesin mutants (ΔclfA and ΔsasC) for nanopore propagation in vitro and osteomyelitis pathogenesis in vivo. In vitro evaluation in the microfluidic silicon membrane-canalicular array (μSiM-CA) showed pbp3, atl, clfA, and sasC deletion reduced nanopore propagation. Using a murine model for implant-associated osteomyelitis, S. aureus cell wall synthesis proteins were found to be key modulators of S. aureus osteomyelitis pathogenesis, while surface adhesins had minimal effects. Specifically, deletion of pbp3 and atl decreased septic implant loosening and S. aureus abscess formation in the medullary cavity, while deletion of surface adhesins showed no significant differences. Further, peri-implant osteolysis, osteoclast activity, and receptor activator of nuclear factor kappa-B ligand (RANKL) production were decreased following pbp3 deletion. Most notably, transmission electron microscopy (TEM) imaging of infected bone showed that pbp3 was the only gene herein associated with decreased submicron invasion of canaliculi in vivo. Together, these results demonstrate that S. aureus cell wall synthesis enzymes are critical for OLCN invasion and osteomyelitis pathogenesis in vivo.
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Affiliation(s)
- Elysia A Masters
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States
| | - Gowrishankar Muthukrishnan
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States
| | - Lananh Ho
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States
| | - Ann Lindley Gill
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States
| | - Karen L de Mesy Bentley
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States.,Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Chad A Galloway
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - James L McGrath
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States
| | - Hani A Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States
| | - Steven R Gill
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States
| | - Edward M Schwarz
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States.,Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States.,Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States.,Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States
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3
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Sharma K, Sultana T, Dahms TES, Dillon JAR. CcpN: a moonlighting protein regulating catabolite repression of gluconeogenic genes in Bacillus subtilis also affects cell length and interacts with DivIVA. Can J Microbiol 2020; 66:723-732. [PMID: 32762636 DOI: 10.1139/cjm-2020-0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CcpN is a transcriptional repressor in Bacillus subtilis that binds to the promoter region of gapB and pckA, downregulating their expression in the presence of glucose. CcpN also represses sr1, which encodes a small noncoding regulatory RNA that suppresses the arginine biosynthesis gene cluster. CcpN has homologues in other Gram-positive bacteria, including Enterococcus faecalis. We report the interaction of CcpN with DivIVA of B. subtilis as determined using bacterial two-hybrid and glutathione S-transferase pull-down assays. Insertional inactivation of CcpN leads to cell elongation and formation of straight chains of cells. These findings suggest that CcpN is a moonlighting protein involved in both gluconeogenesis and cell elongation.
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Affiliation(s)
- Kusum Sharma
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.,Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK S7N 5E3, Canada
| | - Taranum Sultana
- Department of Chemistry and Biochemistry, 3737 Wascana Parkway, University of Regina, Regina, SK S4S 0A2, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, 3737 Wascana Parkway, University of Regina, Regina, SK S4S 0A2, Canada
| | - Jo-Anne R Dillon
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.,Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK S7N 5E3, Canada
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Rismondo J, Halbedel S, Gründling A. Cell Shape and Antibiotic Resistance Are Maintained by the Activity of Multiple FtsW and RodA Enzymes in Listeria monocytogenes. mBio 2019; 10:e01448-19. [PMID: 31387909 PMCID: PMC6686043 DOI: 10.1128/mbio.01448-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022] Open
Abstract
Rod-shaped bacteria have two modes of peptidoglycan synthesis: lateral synthesis and synthesis at the cell division site. These two processes are controlled by two macromolecular protein complexes, the elongasome and divisome. Recently, it has been shown that the Bacillus subtilis RodA protein, which forms part of the elongasome, has peptidoglycan glycosyltransferase activity. The cell division-specific RodA homolog FtsW fulfils a similar role at the divisome. The human pathogen Listeria monocytogenes carries genes that encode up to six FtsW/RodA homologs; however, their functions have not yet been investigated. Analysis of deletion and depletion strains led to the identification of the essential cell division-specific FtsW protein, FtsW1. Interestingly, L. monocytogenes carries a gene that encodes a second FtsW protein, FtsW2, which can compensate for the lack of FtsW1, when expressed from an inducible promoter. L. monocytogenes also possesses three RodA homologs, RodA1, RodA2, and RodA3, and their combined absence is lethal. Cells of a rodA1 rodA3 double mutant are shorter and have increased antibiotic and lysozyme sensitivity, probably due to a weakened cell wall. Results from promoter activity assays revealed that expression of rodA3 and ftsW2 is induced in the presence of antibiotics targeting penicillin binding proteins. Consistent with this, a rodA3 mutant was more susceptible to the β-lactam antibiotic cefuroxime. Interestingly, overexpression of RodA3 also led to increased cefuroxime sensitivity. Our study highlights that L. monocytogenes genes encode a multitude of functional FtsW and RodA enzymes to produce its rigid cell wall and that their expression needs to be tightly regulated to maintain growth, cell division, and antibiotic resistance.IMPORTANCE The human pathogen Listeria monocytogenes is usually treated with high doses of β-lactam antibiotics, often combined with gentamicin. However, these antibiotics only act bacteriostatically on L. monocytogenes, and the immune system is needed to clear the infection. Therefore, individuals with a compromised immune system are at risk to develop a severe form of Listeria infection, which can be fatal in up to 30% of cases. The development of new strategies to treat Listeria infections is necessary. Here we show that the expression of some of the FtsW and RodA enzymes of L. monocytogenes is induced by the presence of β-lactam antibiotics, and the combined absence of these enzymes makes bacteria more susceptible to this class of antibiotics. The development of antimicrobial agents that inhibit the activity or production of FtsW and RodA enzymes might therefore help to improve the treatment of Listeria infections and thereby lead to a reduction in mortality.
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Affiliation(s)
- Jeanine Rismondo
- Section of Microbiology, Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Sven Halbedel
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Angelika Gründling
- Section of Microbiology, Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
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5
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Yamaguchi T, Ando R, Matsumoto T, Ishii Y, Tateda K. Association between cell growth and vancomycin resistance in clinical community-associated methicillin-resistant Staphylococcus aureus. Infect Drug Resist 2019; 12:2379-2390. [PMID: 31534353 PMCID: PMC6682180 DOI: 10.2147/idr.s209591] [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: 03/21/2019] [Accepted: 06/21/2019] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES We investigated the association between the rate of cell growth and vancomycin (VAN) resistance by comparing the genomic and phenotypic characteristics of different sized colonies isolated from a single origin. METHODS Vancomycin-intermediate Staphylococcus aureus (VISA) strain TMUS2136 was isolated from the pus of a patient with a brain abscess and a chronic subdural abscess. This strain grew slowly and formed colonies poorly on agar plates within 24 h of incubation. However, variously sized colonies were observed after 48 h of incubation. We isolated five strains from different sized colonies and compared their VAN susceptibility and genomic sequences using next-generation sequencing. RESULTS The five strains showed different rates of growth and susceptibilities to VAN (range of MIC after 48 h of incubation; 3-5 mg/L), and slower growing strains tended to be more VAN resistant. Deletion of the spdC gene and SNPs in the sarA gene was confirmed in all five strains and six SNPs in other genes (including mreC, hssS, prs, SA2339, sun, and SA1132) were confirmed when comparing the five strains. CONCLUSIONS Deletion of the spdC gene, a novel virulence factor of S. aureus, and SNPs in the sarA gene may be associated with VAN resistance. It was hypothesized that any of the six genes in which SNPs were detected could affect cell growth rate and VAN resistance in slow-VISA strains.
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Affiliation(s)
- Tetsuo Yamaguchi
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
- Department of Microbiology, Tokyo Medical University, Tokyo, Japan
| | - Rina Ando
- Department of Microbiology, Tokyo Medical University, Tokyo, Japan
| | | | - Yoshikazu Ishii
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
| | - Kazuhiro Tateda
- Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan
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Omardien S, Drijfhout JW, Zaat SA, Brul S. Cationic Amphipathic Antimicrobial Peptides Perturb the Inner Membrane of Germinated Spores Thus Inhibiting Their Outgrowth. Front Microbiol 2018; 9:2277. [PMID: 30319583 PMCID: PMC6168669 DOI: 10.3389/fmicb.2018.02277] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/06/2018] [Indexed: 11/13/2022] Open
Abstract
The mode of action of four cationic amphipathic antimicrobial peptides (AMPs) was evaluated against the non-pathogenic, Gram-positive, spore-forming bacterium, Bacillus subtilis. The AMPs were TC19, TC84, BP2, and the lantibiotic Nisin A. TC19 and TC84 were derived from the human thrombocidin-1. Bactericidal peptide 2 (BP2) was derived from the human bactericidal permeability increasing protein (BPI). We employed structured illumination microscopy (SIM), fluorescence microscopy, Alexa 488-labeled TC84, B. subtilis mutants producing proteins fused to the green fluorescent protein (GFP) and single-cell live imaging to determine the effects of the peptides against spores. TC19, TC84, BP2, and Nisin A showed to be bactericidal against germinated spores by perturbing the inner membrane, thus preventing outgrowth to vegetative cells. Single cell live imaging showed that the AMPs do not affect the germination process, but the burst time and subsequent generation time of vegetative cells. Alexa 488-labeled TC84 suggested that the TC84 might be binding to the dormant spore-coat. Therefore, dormant spores were also pre-coated with the AMPs and cultured on AMP-free culture medium during single-cell live imaging. Pre-coating of the spores with TC19, TC84, and BP2 had no effect on the germination process, and variably affected the burst time and generation time. However, the percentage of spores that burst and grew out into vegetative cells was drastically lower when pre-coated with Nisin A, suggesting a novel application potential of this lantibiotic peptide against spores. Our findings contribute to the understanding of AMPs and show the potential of AMPs as eventual therapeutic agents against spore-forming bacteria.
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Affiliation(s)
- Soraya Omardien
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Amsterdam, Netherlands
| | | | - Sebastian A Zaat
- Department of Medical Microbiology, Centre for Infection and Immunity Amsterdam (CINIMA), Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Stanley Brul
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Amsterdam, Netherlands
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7
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Danchin A, Sekowska A, Noria S. Functional Requirements in the Program and the Cell Chassis for Next-Generation Synthetic Biology. Synth Biol (Oxf) 2018. [DOI: 10.1002/9783527688104.ch5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Antoine Danchin
- Institute of Cardiometabolism and Nutrition; 47 boulevard de l'Hôpital Paris 75013 France
| | - Agnieszka Sekowska
- Institute of Cardiometabolism and Nutrition; 47 boulevard de l'Hôpital Paris 75013 France
| | - Stanislas Noria
- Fondation Fourmentin-Guilbert; 2 avenue du Pavé Neuf Noisy le Grand 93160 France
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8
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Shin SM, Song SH, Lee JW, Kwak MK, Kang SO. Methylglyoxal synthase regulates cell elongation via alterations of cellular methylglyoxal and spermidine content in Bacillus subtilis. Int J Biochem Cell Biol 2017; 91:14-28. [PMID: 28807600 DOI: 10.1016/j.biocel.2017.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/14/2017] [Accepted: 08/08/2017] [Indexed: 01/03/2023]
Abstract
Methylglyoxal regulates cell division and differentiation through its interaction with polyamines. Loss of their biosynthesizing enzyme causes physiological impairment and cell elongation in eukaryotes. However, the reciprocal effects of methylglyoxal and polyamine production and its regulatory metabolic switches on morphological changes in prokaryotes have not been addressed. Here, Bacillus subtilis methylglyoxal synthase (mgsA) and polyamine biosynthesizing genes encoding arginine decarboxylase (SpeA), agmatinase (SpeB), and spermidine synthase (SpeE), were disrupted or overexpressed. Treatment of 0.2mM methylglyoxal and 1mM spermidine led to the elongation and shortening of B. subtilis wild-type cells to 12.38±3.21μm (P<0.05) and 3.24±0.73μm (P<0.01), respectively, compared to untreated cells (5.72±0.68μm). mgsA-deficient (mgsA-) and -overexpressing (mgsAOE) mutants also demonstrated cell shortening and elongation, similar to speB- and speE-deficient (speB- and speE-) and -overexpressing (speBOE and speEOE) mutants. Importantly, both mgsA-depleted speBOE and speEOE mutants (speBOE/mgsA- and speEOE/mgsA-) were drastically shortened to 24.5% and 23.8% of parental speBOE and speEOE mutants, respectively. These phenotypes were associated with reciprocal alterations of mgsA and polyamine transcripts governed by the contents of methylglyoxal and spermidine, which are involved in enzymatic or genetic metabolite-control mechanisms. Additionally, biophysically detected methylglyoxal-spermidine Schiff bases did not affect morphogenesis. Taken together, the findings indicate that methylglyoxal triggers cell elongation. Furthermore, cells with methylglyoxal accumulation commonly exhibit an elongated rod-shaped morphology through upregulation of mgsA, polyamine genes, and the global regulator spx, as well as repression of the cell division and shape regulator, FtsZ.
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Affiliation(s)
- Sang-Min Shin
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Sung-Hyun Song
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Jin-Woo Lee
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Min-Kyu Kwak
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
| | - Sa-Ouk Kang
- Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
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Roles of the Essential Protein FtsA in Cell Growth and Division in Streptococcus pneumoniae. J Bacteriol 2017; 199:JB.00608-16. [PMID: 27872183 DOI: 10.1128/jb.00608-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/16/2016] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is an ovoid-shaped Gram-positive bacterium that grows by carrying out peripheral and septal peptidoglycan (PG) synthesis, analogous to model bacilli, such as Escherichia coli and Bacillus subtilis In the model bacilli, FtsZ and FtsA proteins assemble into a ring at midcell and are dedicated to septal PG synthesis but not peripheral PG synthesis; hence, inactivation of FtsZ or FtsA results in long filamentous cells unable to divide. Here, we demonstrate that FtsA and FtsZ colocalize at midcell in S. pneumoniae and that partial depletion of FtsA perturbs septum synthesis, resulting in elongated cells with multiple FtsZ rings that fail to complete septation. Unexpectedly, complete depletion of FtsA resulted in the delocalization of FtsZ rings and ultimately cell ballooning and lysis. In contrast, depletion or deletion of gpsB and sepF, which in B. subtilis are synthetically lethal with ftsA, resulted in enlarged and elongated cells with multiple FtsZ rings, with deletion of sepF mimicking partial depletion of FtsA. Notably, cell ballooning was not observed, consistent with later recruitment of these proteins to midcell after Z-ring assembly. The overproduction of FtsA stimulates septation and suppresses the cell division defects caused by the deletion of sepF and gpsB under some conditions, supporting the notion that FtsA shares overlapping functions with GpsB and SepF at later steps in the division process. Our results indicate that, in S. pneumoniae, both GpsB and SepF are involved in septal PG synthesis, whereas FtsA and FtsZ coordinate both peripheral and septal PG synthesis and are codependent for localization at midcell.IMPORTANCEStreptococcus pneumoniae (pneumococcus) is a clinically important human pathogen for which more therapies against unexploited essential targets, like cell growth and division proteins, are needed. Pneumococcus is an ovoid-shaped Gram-positive bacterium with cell growth and division properties that have important distinctions from those of rod-shaped bacteria. Gaining insights into these processes can thus provide valuable information to develop novel antimicrobials. Whereas rods use distinctly localized protein machines at different cellular locations to synthesize peripheral and septal peptidoglycans, we present evidence that S. pneumoniae organizes these two machines at a single location in the middle of dividing cells. Here, we focus on the properties of the actin-like protein FtsA as an essential orchestrator of peripheral and septal growth in this bacterium.
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10
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Muchová K, Chromiková Z, Bradshaw N, Wilkinson AJ, Barák I. Morphogenic Protein RodZ Interacts with Sporulation Specific SpoIIE in Bacillus subtilis. PLoS One 2016; 11:e0159076. [PMID: 27415800 PMCID: PMC4945075 DOI: 10.1371/journal.pone.0159076] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/27/2016] [Indexed: 12/02/2022] Open
Abstract
The first landmark in sporulation of Bacillus subtilis is the formation of an asymmetric septum followed by selective activation of the transcription factor σF in the resulting smaller cell. How the morphological transformations that occur during sporulation are coupled to cell-specific activation of transcription is largely unknown. The membrane protein SpoIIE is a constituent of the asymmetric sporulation septum and is a crucial determinant of σF activation. Here we report that the morphogenic protein, RodZ, which is essential for cell shape determination, is additionally required for asymmetric septum formation and sporulation. In cells depleted of RodZ, formation of asymmetric septa is disturbed and σF activation is perturbed. During sporulation, we found that SpoIIE recruits RodZ to the asymmetric septum. Moreover, we detected a direct interaction between SpoIIE and RodZ in vitro and in vivo, indicating that SpoIIE-RodZ may form a complex to coordinate asymmetric septum formation and σF activation. We propose that RodZ could provide a link between the cell shape machinery and the coordinated morphological and developmental transitions required to form a resistant spore.
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Affiliation(s)
- Katarína Muchová
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Zuzana Chromiková
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Niels Bradshaw
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Anthony J. Wilkinson
- Structural Biology Laboratory, Department of Chemistry, University of York, York, United Kingdom
| | - Imrich Barák
- Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
- * E-mail:
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11
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Abstract
Disulfide bonds are important for the stability and function of many secreted proteins. In Gram-negative bacteria, these linkages are catalyzed by thiol-disulfide oxidoreductases (Dsb) in the periplasm. Protein oxidation has been well studied in these organisms, but it has not fully been explored in Gram-positive bacteria, which lack traditional periplasmic compartments. Recent bioinformatics analyses have suggested that the high-GC-content bacteria (i.e., actinobacteria) rely on disulfide-bond-forming pathways. In support of this, Dsb-like proteins have been identified in Mycobacterium tuberculosis, but their functions are not known. Actinomyces oris and Corynebacterium diphtheriae have recently emerged as models to study disulfide bond formation in actinobacteria. In both organisms, disulfide bonds are catalyzed by the membrane-bound oxidoreductase MdbA. Remarkably, unlike known Dsb proteins, MdbA is important for pathogenesis and growth, which makes it a potential target for new antibacterial drugs. This review will discuss disulfide-bond-forming pathways in bacteria, with a special focus on Gram-positive bacteria.
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Abstract
All life demands the temporal and spatial control of essential biological functions. In bacteria, the recent discovery of coordinating elements provides a framework to begin to explain cell growth and division. Here we present the discovery of a supramolecular structure in the membrane of the coccal bacterium Staphylococcus aureus, which leads to the formation of a large-scale pattern across the entire cell body; this has been unveiled by studying the distribution of essential proteins involved in lipid metabolism (PlsY and CdsA). The organization is found to require MreD, which determines morphology in rod-shaped cells. The distribution of protein complexes can be explained as a spontaneous pattern formation arising from the competition between the energy cost of bending that they impose on the membrane, their entropy of mixing, and the geometric constraints in the system. Our results provide evidence for the existence of a self-organized and nonpercolating molecular scaffold involving MreD as an organizer for optimal cell function and growth based on the intrinsic self-assembling properties of biological molecules.
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13
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Tavares AC, Fernandes PB, Carballido-López R, Pinho MG. MreC and MreD Proteins Are Not Required for Growth of Staphylococcus aureus. PLoS One 2015; 10:e0140523. [PMID: 26470021 PMCID: PMC4607420 DOI: 10.1371/journal.pone.0140523] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
The transmembrane proteins MreC and MreD are present in a wide variety of bacteria and are thought to be involved in cell shape determination. Together with the actin homologue MreB and other morphological elements, they play an essential role in the synthesis of the lateral cell wall in rod-shaped bacteria. In ovococcus, which lack MreB homologues, mreCD are also essential and have been implicated in peripheral cell wall synthesis. In this work we addressed the possible roles of MreC and MreD in the spherical pathogen Staphylococcus aureus. We show that MreC and MreD are not essential for cell viability and do not seem to affect cell morphology, cell volume or cell cycle control. MreC and MreD localize preferentially to the division septa, but do not appear to influence peptidoglycan composition, nor the susceptibility to different antibiotics and to oxidative and osmotic stress agents. Our results suggest that the function of MreCD in S. aureus is not critical for cell division and cell shape determination.
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Affiliation(s)
- Andreia C. Tavares
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Pedro B. Fernandes
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Rut Carballido-López
- INRA, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France
- AgroParisTech, UMR Micalis, F-78350, Jouy-en-Josas, France
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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14
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Manzoor I, Shafeeq S, Kloosterman TG, Kuipers OP. Co(2+)-dependent gene expression in Streptococcus pneumoniae: opposite effect of Mn(2+) and Co(2+) on the expression of the virulence genes psaBCA, pcpA, and prtA. Front Microbiol 2015; 6:748. [PMID: 26257722 PMCID: PMC4513243 DOI: 10.3389/fmicb.2015.00748] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/08/2015] [Indexed: 11/13/2022] Open
Abstract
Manganese (Mn(2+))-, zinc (Zn(2+))- and copper (Cu(2+)) play significant roles in transcriptional gene regulation, physiology, and virulence of Streptococcus pneumoniae. So far, the effect of the important transition metal ion cobalt (Co(2+)) on gene expression of S. pneumoniae has not yet been explored. Here, we study the impact of Co(2+) stress on the transcriptome of S. pneumoniae strain D39. BLAST searches revealed that the genome of S. pneumoniae encodes a putative Co(2+)-transport operon (cbi operon), the expression of which we show here to be induced by a high Co(2+) concentration. Furthermore, we found that Co(2+), as has been shown previously for Zn(2+), can cause derepression of the genes of the PsaR virulence regulon, encoding the Mn(2+)-uptake system PsaBCA, the choline binding protein PcpA and the cell-wall associated serine protease PrtA. Interestingly, although Mn(2+) represses expression of the PsaR regulon and Co(2+) leads to derepression, both metal ions stimulate interaction of PsaR with its target promoters. These data will be discussed in the light of previous studies on similar metal-responsive transcriptional regulators.
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Affiliation(s)
- Irfan Manzoor
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands ; Department of Bioinformatics and Biotechnology, Government College University Faisalabad, Pakistan
| | - Sulman Shafeeq
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands ; Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm Sweden
| | - Tomas G Kloosterman
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
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15
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Donovan C, Heyer A, Pfeifer E, Polen T, Wittmann A, Krämer R, Frunzke J, Bramkamp M. A prophage-encoded actin-like protein required for efficient viral DNA replication in bacteria. Nucleic Acids Res 2015; 43:5002-16. [PMID: 25916847 PMCID: PMC4446434 DOI: 10.1093/nar/gkv374] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/09/2015] [Indexed: 12/31/2022] Open
Abstract
In host cells, viral replication is localized at specific subcellular sites. Viruses that infect eukaryotic and prokaryotic cells often use host-derived cytoskeletal structures, such as the actin skeleton, for intracellular positioning. Here, we describe that a prophage, CGP3, integrated into the genome of Corynebacterium glutamicum encodes an actin-like protein, AlpC. Biochemical characterization confirms that AlpC is a bona fide actin-like protein and cell biological analysis shows that AlpC forms filamentous structures upon prophage induction. The co-transcribed adaptor protein, AlpA, binds to a consensus sequence in the upstream promoter region of the alpAC operon and also interacts with AlpC, thus connecting circular phage DNA to the actin-like filaments. Transcriptome analysis revealed that alpA and alpC are among the early induced genes upon excision of the CGP3 prophage. Furthermore, qPCR analysis of mutant strains revealed that both AlpA and AlpC are required for efficient phage replication. Altogether, these data emphasize that AlpAC are crucial for the spatio-temporal organization of efficient viral replication. This is remarkably similar to actin-assisted membrane localization of eukaryotic viruses that use the actin cytoskeleton to concentrate virus particles at the egress sites and provides a link of evolutionary conserved interactions between intracellular virus transport and actin.
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Affiliation(s)
- Catriona Donovan
- Department of Biology I, Ludwig-Maximilians-University Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany Institute for Biochemistry, University of Cologne, Zülpicherstr. 47, 50674 Cologne, Germany
| | - Antonia Heyer
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Eugen Pfeifer
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Tino Polen
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Anja Wittmann
- Institute for Biochemistry, University of Cologne, Zülpicherstr. 47, 50674 Cologne, Germany
| | - Reinhard Krämer
- Institute for Biochemistry, University of Cologne, Zülpicherstr. 47, 50674 Cologne, Germany
| | - Julia Frunzke
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Marc Bramkamp
- Department of Biology I, Ludwig-Maximilians-University Munich, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany Institute for Biochemistry, University of Cologne, Zülpicherstr. 47, 50674 Cologne, Germany
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16
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Schirner K, Eun YJ, Dion M, Luo Y, Helmann JD, Garner EC, Walker S. Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB. Nat Chem Biol 2015; 11:38-45. [PMID: 25402772 PMCID: PMC4270829 DOI: 10.1038/nchembio.1689] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/11/2014] [Indexed: 12/14/2022]
Abstract
The bacterial actin homolog MreB, which is crucial for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of lipid-linked peptidoglycan precursors. When precursors are depleted, MreB filaments disassemble into the cytoplasm, and peptidoglycan synthesis becomes disorganized. In cells that lack wall teichoic acids but continue to make peptidoglycan, dynamic MreB filaments are observed, although their presence is not sufficient to establish a rod shape. We propose that the cell regulates MreB filament association with the membrane, allowing rapid and reversible inactivation of cell wall enzyme complexes in response to the inhibition of cell wall synthesis.
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Affiliation(s)
- Kathrin Schirner
- Department of Microbiology and Immunobiology, Harvard Medical School,
Boston, MA 02115, USA
| | - Ye-Jin Eun
- Department of Molecular and Cellular Biology, Harvard University, Cambridge,
MA 02138, USA
| | - Mike Dion
- Department of Molecular and Cellular Biology, Harvard University, Cambridge,
MA 02138, USA
| | - Yun Luo
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - John D. Helmann
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Ethan C. Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge,
MA 02138, USA
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard Medical School,
Boston, MA 02115, USA
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17
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Fritz G, Mascher T. A balancing act times two: sensing and regulating cell envelope homeostasis inBacillus subtilis. Mol Microbiol 2014; 94:1201-7. [DOI: 10.1111/mmi.12848] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2014] [Indexed: 01/09/2023]
Affiliation(s)
- Georg Fritz
- LOEWE Center for Synthetic MicrobiologyPhilipps‐University Marburg 35043 Marburg Germany
| | - Thorsten Mascher
- Department Biology I, MicrobiologyLudwig‐Maximilians‐Universität München Großhaderner Str. 2‐4 82152 Planegg‐Martinsried Germany
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18
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Takada H, Fukushima-Tanaka S, Morita M, Kasahara Y, Watanabe S, Chibazakura T, Hara H, Matsumoto K, Yoshikawa H. An essential enzyme for phospholipid synthesis associates with theBacillus subtilisdivisome. Mol Microbiol 2013; 91:242-55. [DOI: 10.1111/mmi.12457] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Hiraku Takada
- Department of Bioscience; Tokyo University of Agriculture; 1-1-1 Sakuragaoka Setagaya-ku Tokyo 156-8502 Japan
| | - Sanae Fukushima-Tanaka
- Department of Bioscience; Tokyo University of Agriculture; 1-1-1 Sakuragaoka Setagaya-ku Tokyo 156-8502 Japan
| | - Masato Morita
- Department of Bioscience; Tokyo University of Agriculture; 1-1-1 Sakuragaoka Setagaya-ku Tokyo 156-8502 Japan
| | - Yasuhiro Kasahara
- Institute of Low Temperature Science; Hokkaido University; Kita 19 Nishi 8 Kita-ku Sapporo Hokkaido Japan
| | - Satoru Watanabe
- Department of Bioscience; Tokyo University of Agriculture; 1-1-1 Sakuragaoka Setagaya-ku Tokyo 156-8502 Japan
| | - Taku Chibazakura
- Department of Bioscience; Tokyo University of Agriculture; 1-1-1 Sakuragaoka Setagaya-ku Tokyo 156-8502 Japan
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology; Graduate School of Science and Engineering; Saitama University; 255 Shimo-ohkubo Sakura Saitama 338-8570 Japan
| | - Kouji Matsumoto
- Department of Biochemistry and Molecular Biology; Graduate School of Science and Engineering; Saitama University; 255 Shimo-ohkubo Sakura Saitama 338-8570 Japan
| | - Hirofumi Yoshikawa
- Department of Bioscience; Tokyo University of Agriculture; 1-1-1 Sakuragaoka Setagaya-ku Tokyo 156-8502 Japan
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19
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Huang WZ, Wang JJ, Chen HJ, Chen JT, Shaw GC. The heat-inducible essential response regulator WalR positively regulates transcription of sigI, mreBH and lytE in Bacillus subtilis under heat stress. Res Microbiol 2013; 164:998-1008. [DOI: 10.1016/j.resmic.2013.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 09/16/2013] [Indexed: 01/15/2023]
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20
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Domínguez-Cuevas P, Porcelli I, Daniel RA, Errington J. Differentiated roles for MreB-actin isologues and autolytic enzymes in Bacillus subtilis morphogenesis. Mol Microbiol 2013; 89:1084-98. [PMID: 23869552 PMCID: PMC3817527 DOI: 10.1111/mmi.12335] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2013] [Indexed: 12/20/2022]
Abstract
Cell morphogenesis in most bacteria is governed by spatiotemporal growth regulation of the peptidoglycan cell wall layer. Much is known about peptidoglycan synthesis but regulation of its turnover by hydrolytic enzymes is much less well understood. Bacillus subtilis has a multitude of such enzymes. Two of the best characterized are CwlO and LytE: cells lacking both enzymes have a lethal block in cell elongation. Here we show that activity of CwlO is regulated by an ABC transporter, FtsEX, which is required for cell elongation, unlike cell division as in Escherichia coli. Actin-like MreB proteins are thought to play a key role in orchestrating cell wall morphogenesis. B. subtilis has three MreB isologues with partially differentiated functions. We now show that the three MreB isologues have differential roles in regulation of the CwlO and LytE systems and that autolysins control different aspects of cell morphogenesis. The results add major autolytic activities to the growing list of functions controlled by MreB isologues in bacteria and provide new insights into the different specialized functions of essential cell wall autolysins.
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Affiliation(s)
- Patricia Domínguez-Cuevas
- Centre for Bacterial Cell Biology, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
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21
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Massidda O, Nováková L, Vollmer W. From models to pathogens: how much have we learned about Streptococcus pneumoniae cell division? Environ Microbiol 2013; 15:3133-57. [PMID: 23848140 DOI: 10.1111/1462-2920.12189] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/08/2013] [Accepted: 06/09/2013] [Indexed: 12/22/2022]
Abstract
Streptococcus pneumoniae is an oval-shaped Gram-positive coccus that lives in intimate association with its human host, both as a commensal and pathogen. The seriousness of pneumococcal infections and the spread of multi-drug resistant strains call for new lines of intervention. Bacterial cell division is an attractive target to develop antimicrobial drugs. This review discusses the recent advances in understanding S. pneumoniae growth and division, in comparison with the best studied rod-shaped models, Escherichia coli and Bacillus subtilis. To maintain their shape, these bacteria propagate by peripheral and septal peptidoglycan synthesis, involving proteins that assemble into distinct complexes called the elongasome and the divisome, respectively. Many of these proteins are conserved in S. pneumoniae, supporting the notion that the ovococcal shape is also achieved by rounds of elongation and division. Importantly, S. pneumoniae and close relatives with similar morphology differ in several aspects from the model rods. Overall, the data support a model in which a single large machinery, containing both the peripheral and septal peptidoglycan synthesis complexes, assembles at midcell and governs growth and division. The mechanisms generating the ovococcal or coccal shape in lactic-acid bacteria have likely evolved by gene reduction from a rod-shaped ancestor of the same group.
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Affiliation(s)
- Orietta Massidda
- Department of Surgical Sciences, University of Cagliari, Via Porcell, 4, 09100, Cagliari, Italy
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22
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Salzberg LI, Powell L, Hokamp K, Botella E, Noone D, Devine KM. The WalRK (YycFG) and σ(I) RsgI regulators cooperate to control CwlO and LytE expression in exponentially growing and stressed Bacillus subtilis cells. Mol Microbiol 2012. [PMID: 23199363 DOI: 10.1111/mmi.12092] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The WalRK (YycFG) two-component system co-ordinates cell wall metabolism with growth by regulating expression of autolysins and proteins that modulate autolysin activity. Here we extend its role in cell wall metabolism by showing that WalR binds to 22 chromosomal loci in vivo. Among the newly identified genes of the WalRK bindome are those that encode the wall-associated protein WapA, the penicillin binding proteins PbpH and Pbp5, the minor teichoic acid synthetic enzymes GgaAB and the regulators σ(I) RsgI. The putative WalR binding sequence at many newly identified binding loci deviates from the previously defined consensus. Moreover, expression of many newly identified operons is controlled by multiple regulators. An unusual feature is that WalR binds to an extended DNA region spanning multiple open reading frames at some loci. WalRK directly activates expression of the sigIrsgI operon from a newly identified σ(A) promoter and represses expression from the previously identified σ(I) promoter. We propose that this regulatory link between WalRK and σ(I) RsgI expression ensures that the endopeptidase requirement (CwlO or LytE) for cell viability is fulfilled during growth and under stress conditions. Thus the WalRK and σ(I) RsgI regulatory systems cooperate to control cell wall metabolism in growing and stressed cells.
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Affiliation(s)
- Letal I Salzberg
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2. Ireland
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23
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Tuson HH, Auer GK, Renner LD, Hasebe M, Tropini C, Salick M, Crone WC, Gopinathan A, Huang KC, Weibel DB. Measuring the stiffness of bacterial cells from growth rates in hydrogels of tunable elasticity. Mol Microbiol 2012; 84:874-91. [PMID: 22548341 DOI: 10.1111/j.1365-2958.2012.08063.x] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although bacterial cells are known to experience large forces from osmotic pressure differences and their local microenvironment, quantitative measurements of the mechanical properties of growing bacterial cells have been limited. We provide an experimental approach and theoretical framework for measuring the mechanical properties of live bacteria. We encapsulated bacteria in agarose with a user-defined stiffness, measured the growth rate of individual cells and fit data to a thin-shell mechanical model to extract the effective longitudinal Young's modulus of the cell envelope of Escherichia coli (50-150 MPa), Bacillus subtilis (100-200 MPa) and Pseudomonas aeruginosa (100-200 MPa). Our data provide estimates of cell wall stiffness similar to values obtained via the more labour-intensive technique of atomic force microscopy. To address physiological perturbations that produce changes in cellular mechanical properties, we tested the effect of A22-induced MreB depolymerization on the stiffness of E. coli. The effective longitudinal Young's modulus was not significantly affected by A22 treatment at short time scales, supporting a model in which the interactions between MreB and the cell wall persist on the same time scale as growth. Our technique therefore enables the rapid determination of how changes in genotype and biochemistry affect the mechanical properties of the bacterial envelope.
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Affiliation(s)
- Hannah H Tuson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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24
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Luo Y, Helmann JD. Analysis of the role of Bacillus subtilis σ(M) in β-lactam resistance reveals an essential role for c-di-AMP in peptidoglycan homeostasis. Mol Microbiol 2012; 83:623-39. [PMID: 22211522 DOI: 10.1111/j.1365-2958.2011.07953.x] [Citation(s) in RCA: 186] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Bacillus subtilis extracytoplasmic function (ECF) σ factor σ(M) is inducible by, and confers resistance to, several cell envelope-acting antibiotics. Here, we demonstrate that σ(M) is responsible for intrinsic β-lactam resistance, with σ(X) playing a secondary role. Activation of σ(M) upregulates several cell wall biosynthetic enzymes including one, PBP1, shown here to be a target for the beta-lactam cefuroxime. However, σ(M) still plays a major role in cefuroxime resistance even in cells lacking PBP1. To better define the role of σ(M) in β-lactam resistance, we characterized suppressor mutations that restore cefuroxime resistance to a sigM null mutant. The most frequent suppressors inactivated gdpP (yybT) which encodes a cyclic-di-AMP phosphodiesterase (PDE). Intriguingly, σ(M) is a known activator of disA encoding one of three paralogous diadenylate cyclases (DAC). Overproduction of the GdpP PDE greatly sensitized cells to β-lactam antibiotics. Conversely, genetic studies indicate that at least one DAC is required for growth with depletion leading to cell lysis. These findings support a model in which c-di-AMP is an essential signal molecule required for cell wall homeostasis. Other suppressors highlight the roles of ECF σ factors in counteracting the deleterious effects of autolysins and reactive oxygen species in β-lactam-treated cells.
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Affiliation(s)
- Yun Luo
- Department of Microbiology, Cornell University, Ithaca, NY 14853-8101, USA
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25
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Pinto E, Marques N, W. Andrew P, Leonor Faleiro M. Over-Production of P60 Family Proteins, Glycolytic and Stress Response Proteins Characterizes the Autolytic Profile of <i>Listeria monocytogenes</i>. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/aim.2012.22023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Abstract
Leptospira spp. are thin, highly motile, slow-growing spirochetes that can be distinguished from other bacteria on the basis of their unique helical shape. Defining the mechanisms by which these bacteria generate and maintain this atypical morphology should greatly enhance our understanding of the fundamental physiology of these pathogens. In this study, we showed that peptidoglycan sacculi from Leptospira spp. retain the helical shape of intact cells. Interestingly, the distribution of muropeptides was different from that in the Escherichia coli model, indicating that specific enzymes might be active on the peptidoglycan macromolecule. We could alter the shape of Leptospira biflexa with the broad-spectrum β-lactam antibiotic penicillin G and with amdinocillin and aztreonam, which are β-lactams that preferentially target penicillin-binding protein 2 (PBP2) and PBP3, respectively, in some species. Although genetic manipulations of Leptospira spp. are scarce, we were able to obtain mutants with alterations in genes encoding PBPs, including PBP3. Loss of this protein resulted in cell elongation. We also generated an L. biflexa strain that conditionally expresses MreB. Loss of the MreB function was correlated with morphological abnormalities such as a localized increased diameter and heterogeneous length. A prolonged depletion of MreB resulted in cell lysis, suggesting that this protein is essential. These findings indicate that important aspects of leptospiral cell morphology are determined by the cytoskeleton and the murein layer, thus providing a starting point for a better understanding of the morphogenesis in these atypical bacteria.
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El Ghachi M, Matteï PJ, Ecobichon C, Martins A, Hoos S, Schmitt C, Colland F, Ebel C, Prévost MC, Gabel F, England P, Dessen A, Boneca IG. Characterization of the elongasome core PBP2 : MreC complex of Helicobacter pylori. Mol Microbiol 2011; 82:68-86. [PMID: 21801243 DOI: 10.1111/j.1365-2958.2011.07791.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The definition of bacterial cell shape is a complex process requiring the participation of multiple components of an intricate macromolecular machinery. We aimed at characterizing the determinants involved in cell shape of the helical bacterium Helicobacter pylori. Using a yeast two-hybrid screen with the key cell elongation protein PBP2 as bait, we identified an interaction between PBP2 and MreC. The minimal region of MreC required for this interaction ranges from amino acids 116 to 226. Using recombinant proteins, we showed by affinity and size exclusion chromatographies and surface plasmon resonance that PBP2 and MreC form a stable complex. In vivo, the two proteins display a similar spatial localization and their complex has an apparent 1:1 stoichiometry; these results were confirmed in vitro by analytical ultracentrifugation and chemical cross-linking. Small angle X-ray scattering analyses of the PBP2 : MreC complex suggest that MreC interacts directly with the C-terminal region of PBP2. Depletion of either PBP2 or MreC leads to transition into spherical cells that lose viability. Finally, the specific expression in trans of the minimal interacting domain of MreC with PBP2 in the periplasmic space leads to cell rounding, suggesting that the PBP2/MreC complex formation in vivo is essential for cell morphology.
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Affiliation(s)
- Meriem El Ghachi
- Institut Pasteur, Group Biology and Genetics of the Bacterial Cell Wall, F-75015 Paris, France
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28
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Corrigan RM, Abbott JC, Burhenne H, Kaever V, Gründling A. c-di-AMP is a new second messenger in Staphylococcus aureus with a role in controlling cell size and envelope stress. PLoS Pathog 2011; 7:e1002217. [PMID: 21909268 PMCID: PMC3164647 DOI: 10.1371/journal.ppat.1002217] [Citation(s) in RCA: 331] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 07/08/2011] [Indexed: 01/20/2023] Open
Abstract
The cell wall is a vital and multi-functional part of bacterial cells. For Staphylococcus aureus, an important human bacterial pathogen, surface proteins and cell wall polymers are essential for adhesion, colonization and during the infection process. One such cell wall polymer, lipoteichoic acid (LTA), is crucial for normal bacterial growth and cell division. Upon depletion of this polymer bacteria increase in size and a misplacement of division septa and eventual cell lysis is observed. In this work, we describe the isolation and characterization of LTA-deficient S. aureus suppressor strains that regained the ability to grow almost normally in the absence of this cell wall polymer. Using a whole genome sequencing approach, compensatory mutations were identified and revealed that mutations within one gene, gdpP (GGDEF domain protein containing phosphodiesterase), allow both laboratory and clinical isolates of S. aureus to grow without LTA. It was determined that GdpP has phosphodiesterase activity in vitro and uses the cyclic dinucleotide c-di-AMP as a substrate. Furthermore, we show for the first time that c-di-AMP is produced in S. aureus presumably by the S. aureus DacA protein, which has diadenylate cyclase activity. We also demonstrate that GdpP functions in vivo as a c-di-AMP-specific phosphodiesterase, as intracellular c-di-AMP levels increase drastically in gdpP deletion strains and in an LTA-deficient suppressor strain. An increased amount of cross-linked peptidoglycan was observed in the gdpP mutant strain, a cell wall alteration that could help bacteria compensate for the lack of LTA. Lastly, microscopic analysis of wild-type and gdpP mutant strains revealed a 13–22% reduction in the cell size of bacteria with increased c-di-AMP levels. Taken together, these data suggest a function for this novel secondary messenger in controlling cell size of S. aureus and in helping bacteria to cope with extreme membrane and cell wall stress. Staphylococcus aureus is an important human pathogen that colonizes the nares and skin of both sick and healthy individuals and causes a variety of infections ranging from superficial skin to invasive infections. The ability of this bacterium to cause disease depends on many factors and is, in part, due to multi-functional cell surface structures. One such structure is lipoteichoic acid (LTA), which is crucial for bacterial growth. In this study we show that LTA is also important for growth of a clinically relevant community-acquired methicillin resistant S. aureus (CA-MRSA) strain and not only for laboratory strains as previously described. We set out to investigate if S. aureus can find a way to survive without LTA and identified strains that can grow and divide almost normally in its absence. Using a whole genome sequencing approach, we found that alterations in one gene, gdpP, allow these strains to grow in the absence of LTA. We show that this mutation causes an increase in the recently identified signaling molecule, c-di-AMP, within the cell. Therefore, with this study we provide information on one of the first functions of this novel secondary messenger, which is in helping bacteria to cope with extreme cell wall stress.
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Affiliation(s)
| | - James C. Abbott
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Heike Burhenne
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Volkhard Kaever
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Angelika Gründling
- Section of Microbiology, Imperial College London, London, United Kingdom
- * E-mail:
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Fujinami S, Sato T, Ito M. The relationship between a coiled morphology and Mbl in alkaliphilic Bacillus halodurans C-125 at neutral pH values. Extremophiles 2011; 15:587-96. [PMID: 21786127 DOI: 10.1007/s00792-011-0389-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 07/04/2011] [Indexed: 11/30/2022]
Abstract
The facultative alkaliphilic Bacillus halodurans C-125 can grow in a pH range from 6.8 to 10.8. The morphology of the cells grown at pH values above 7.5 is rod shaped, whereas, that gown at pH values less than 7.5 is coiled. Cytoplasmic membrane staining revealed that this coiled morphology was formed not by one filamentous cell, but by many chained bent/non-bent cells. Prokaryotic actin and tubulin homologs (MreB, Mbl MreBH, and FtsZ, respectively) are known to function as bacterial cytoskeleton proteins. The transcription levels of ftsZ, mreB, and mreBH genes were hardly affected by growth pH. However, the level of the mbl gene was significantly decreased at neutral pH values. Moreover, the expression level of the Mbl protein at pH 7.0 was about one-fourth of that at pH 10. Immunofluorescence microscopy (IFM) showed that the Mbl protein was localized as a helical structure in the rod-shaped cell grown at pH 10, whereas a helical structure was not observed in the cells grown at pH 7.0. Fluorescent vancomycin staining showed insertion of new peptidoglycan strands of sidewalls occurred in the cells grown at pH 7.0. These data suggested that a decrease in the expression level of the Mbl protein can influence the morphology of B. halodurans C-125 grown at pH 7.0 without influencing insertion of new peptidoglycan strands.
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Affiliation(s)
- Shun Fujinami
- Bio-Nano Electronics Research Centre, Toyo University, Kawagoe, Saitama, Japan.
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30
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The requirement for pneumococcal MreC and MreD is relieved by inactivation of the gene encoding PBP1a. J Bacteriol 2011; 193:4166-79. [PMID: 21685290 DOI: 10.1128/jb.05245-11] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
MreC and MreD, along with the actin homologue MreB, are required to maintain the shape of rod-shaped bacteria. The depletion of MreCD in rod-shaped bacteria leads to the formation of spherical cells and the accumulation of suppressor mutations. Ovococcus bacteria, such as Streptococcus pneumoniae, lack MreB homologues, and the functions of the S. pneumoniae MreCD (MreCD(Spn)) proteins are unknown. mreCD are located upstream from the pcsB cell division gene in most Streptococcus species, but we found that mreCD and pcsB are transcribed independently. Similarly to rod-shaped bacteria, we show that mreCD are essential in the virulent serotype 2 D39 strain of S. pneumoniae, and the depletion of MreCD results in cell rounding and lysis. In contrast, laboratory strain R6 contains suppressors that allow the growth of ΔmreCD mutants, and bypass suppressors accumulate in D39 ΔmreCD mutants. One class of suppressors eliminates the function of class A penicillin binding protein 1a (PBP1a). Unencapsulated Δpbp1a D39 mutants have smaller diameters than their pbp1a(+) parent or Δpbp2a and Δpbp1b mutants, which lack other class A PBPs and do not show the suppression of ΔmreCD mutations. Suppressed ΔmreCD Δpbp1a double mutants form aberrantly shaped cells, some with misplaced peptidoglycan (PG) biosynthesis compared to that of single Δpbp1a mutants. Quantitative Western blotting showed that MreC(Spn) is abundant (≈8,500 dimers per cell), and immunofluorescent microscopy (IFM) located MreCD(Spn) to the equators and septa of dividing cells, similarly to the PBPs and PG pentapeptides indicative of PG synthesis. These combined results are consistent with a model in which MreCD(Spn) direct peripheral PG synthesis and control PBP1a localization or activity.
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31
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Botella E, Hübner S, Hokamp K, Hansen A, Bisicchia P, Noone D, Powell L, Salzberg LI, Devine KM. Cell envelope gene expression in phosphate-limited Bacillus subtilis cells. MICROBIOLOGY-SGM 2011; 157:2470-2484. [PMID: 21636651 DOI: 10.1099/mic.0.049205-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The high phosphate content of Bacillus subtilis cell walls dictates that cell wall metabolism is an important feature of the PhoPR-mediated phosphate limitation response. Here we report the expression profiles of cell-envelope-associated and PhoPR regulon genes, determined by live cell array and transcriptome analysis, in exponentially growing and phosphate-limited B. subtilis cells. Control by the WalRK two-component system confers a unique expression profile and high level of promoter activity on the genes of its regulon with yocH and cwlO expression differing both qualitatively and quantitatively from all other autolysin-encoding genes examined. The activity of the PhoPR two-component system is restricted to the phosphate-limited state, being rapidly induced in response to the cognate stimulus, and can be sustained for an extended phosphate limitation period. Constituent promoters of the PhoPR regulon show heterogeneous induction profiles and very high promoter activities. Phosphate-limited cells also show elevated expression of the actin-like protein MreBH and reduced expression of the WapA cell wall protein and WprA cell wall protease indicating that cell wall metabolism in this state is distinct from that of exponentially growing and stationary-phase cells. The PhoPR response is very rapidly deactivated upon removal of the phosphate limitation stimulus with concomitant increased expression of cell wall metabolic genes. Moreover expression of genes encoding enzymes involved in sulphur metabolism is significantly altered in the phosphate-limited state with distinct perturbations being observed in wild-type 168 and AH024 (ΔphoPR) cells.
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Affiliation(s)
- Eric Botella
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Sebastian Hübner
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Karsten Hokamp
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Annette Hansen
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Paola Bisicchia
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - David Noone
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Leagh Powell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Letal I Salzberg
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Kevin M Devine
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
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Dominguez-Escobar J, Chastanet A, Crevenna AH, Fromion V, Wedlich-Soldner R, Carballido-Lopez R. Processive Movement of MreB-Associated Cell Wall Biosynthetic Complexes in Bacteria. Science 2011; 333:225-8. [DOI: 10.1126/science.1203466] [Citation(s) in RCA: 410] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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33
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Determining cell shape: adaptive regulation of cyanobacterial cellular differentiation and morphology. Trends Microbiol 2011; 19:278-85. [PMID: 21458273 DOI: 10.1016/j.tim.2011.03.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 02/23/2011] [Accepted: 03/02/2011] [Indexed: 02/04/2023]
Abstract
Similar to other bacteria, cyanobacteria exist in a wide-ranging diversity of shapes and sizes. However, three general shapes are observed most frequently: spherical, rod and spiral. Bacteria can also grow as filaments of cells. Some filamentous cyanobacteria have differentiated cell types that exhibit distinct morphologies: motile hormogonia, nitrogen-fixing heterocysts, and spore-like akinetes. Cyanobacterial cell shapes, which are largely controlled by the cell wall, can be regulated by developmental and/or environmental cues, although the mechanisms of regulation and the selective advantage(s) of regulating cellular shape are still being elucidated. In this review, recent insights into developmental and environmental regulation of cell shape in cyanobacteria and the relationship(s) of cell shape and differentiation to organismal fitness are discussed.
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Kleinschnitz EM, Heichlinger A, Schirner K, Winkler J, Latus A, Maldener I, Wohlleben W, Muth G. Proteins encoded by the mre gene cluster in Streptomyces coelicolor A3(2) cooperate in spore wall synthesis. Mol Microbiol 2011; 79:1367-79. [PMID: 21244527 DOI: 10.1111/j.1365-2958.2010.07529.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is still an open question how an intracellular cytoskeleton directs the synthesis of the peptidoglycan exoskeleton. In contrast to MreB of rod-shaped bacteria, which is essential for lateral cell wall synthesis, MreB of Streptomyces coelicolor has a role in sporulation. To study the function of the S. coelicolor mre gene cluster consisting of mreB, mreC, mreD, pbp2 and sfr, we generated non-polar replacement mutants. The individual mutants were viable and growth of substrate mycelium was not affected. However, all mutants produced enlarged spores, which frequently germinated prematurely and were sensitive to heat, high osmolarity and cell wall damaging agents. Protein-protein interaction assays by bacterial two-hybrid analyses indicated that the S. coelicolor Mre proteins form a spore wall synthesizing complex, which closely resembles the lateral wall synthesizing complex of rod-shaped bacteria. Screening of a genomic library identified several novel putative components of this complex. One of them (sco2097) was deleted. The Δsco2097 mutant formed sensitive spores with an aberrant morphology, demonstrating that SCO2097 is a new player in cell morphogenesis of Streptomyces. Our results suggest that all Mre proteins cooperate with the newly identified proteins in the synthesis of the thickened spore wall required to resist detrimental environmental conditions.
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Affiliation(s)
- Eva-Maria Kleinschnitz
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin Tübingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Deutschland
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Pérez-Núñez D, Briandet R, David B, Gautier C, Renault P, Hallet B, Hols P, Carballido-López R, Guédon E. A new morphogenesis pathway in bacteria: unbalanced activity of cell wall synthesis machineries leads to coccus-to-rod transition and filamentation in ovococci. Mol Microbiol 2010; 79:759-71. [PMID: 21255117 DOI: 10.1111/j.1365-2958.2010.07483.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacteria display a variety of shapes, which have biological relevance. In most eubacteria, cell shape is maintained by the tough peptidoglycan (PG) layer of the cell wall, the sacculus. The organization of PG synthesis machineries, orchestrated by different cytoskeletal elements, determines the specific shapes of sacculi. In rod-shaped bacteria, the actin-like (MreB) and the tubuline-like (FtsZ) cytoskeletons control synthesis of the sidewall (elongation) and the crosswall (septation) respectively. Much less is known concerning cell morphogenesis in cocci, which lack MreB proteins. While spherical cocci exclusively display septal growth, ovococci additionally display peripheral growth, which is responsible of the slight longitudinal expansion that generates their ovoid shape. Here, we report that the ovococcus Lactococcus lactis has the ability to become rod-shaped. L. lactis IL1403 wild-type cells form long aseptate filaments during both biofilm and planktonic growth in a synthetic medium. Nascent PG insertion and the division protein FtsK localize in multiple peripheral rings regularly spaced along the filaments. We show that filamentation results from septation inhibition, and that penicillin-binding proteins PBP2x and PBP2b play a direct role in this process. We propose a model for filament formation in L. lactis, and discuss the possible biological role of such morphological differentiation.
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Affiliation(s)
- Daniel Pérez-Núñez
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352 Jouy-en-Josas, France
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Abstract
Events in the past decade have made it both possible and interesting to ask how bacteria create cells of defined length, diameter, and morphology. The current consensus is that bacterial shape is determined by the coordinated activities of cytoskeleton complexes that drive cell elongation and division. Cell length is most easily explained by the timing of cell division, principally by regulating the activity of the FtsZ protein. However, the question of how cells establish and maintain a specific and uniform diameter is, by far, much more difficult to answer. Mutations associated with the elongation complex often alter cell width, though it is not clear how. Some evidence suggests that diameter is strongly influenced by events during cell division. In addition, surprising new observations show that the bacterial cell wall is more highly malleable than previously believed and that cells can alter and restore their shapes by relying only on internal mechanisms.
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Affiliation(s)
- Kevin D Young
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205-7199, USA.
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Makarova KS, Yutin N, Bell SD, Koonin EV. Evolution of diverse cell division and vesicle formation systems in Archaea. Nat Rev Microbiol 2010; 8:731-41. [PMID: 20818414 DOI: 10.1038/nrmicro2406] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recently a novel cell division system comprised of homologues of eukaryotic ESCRT-III (endosomal sorting complex required for transport III) proteins was discovered in the hyperthermophilic crenarchaeote Sulfolobus acidocaldarius. On the basis of this discovery, we undertook a comparative genomic analysis of the machineries for cell division and vesicle formation in Archaea. Archaea possess at least three distinct membrane remodelling systems: the FtsZ-based bacterial-type system, the ESCRT-III-based eukaryote-like system and a putative novel system that uses an archaeal actin-related protein. Many archaeal genomes encode assortments of components from different systems. Evolutionary reconstruction from these findings suggests that the last common ancestor of the extant Archaea possessed a complex membrane remodelling apparatus, different components of which were lost during subsequent evolution of archaeal lineages. By contrast, eukaryotes seem to have inherited all three ancestral systems.
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Affiliation(s)
- Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
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Bisicchia P, Lioliou E, Noone D, Salzberg LI, Botella E, Hübner S, Devine KM. Peptidoglycan metabolism is controlled by the WalRK (YycFG) and PhoPR two-component systems in phosphate-limited Bacillus subtilis cells. Mol Microbiol 2010; 75:972-89. [PMID: 20487291 DOI: 10.1111/j.1365-2958.2009.07036.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In Bacillus subtilis, the WalRK (YycFG) two-component system controls peptidoglycan metabolism in exponentially growing cells while PhoPR controls the response to phosphate limitation. Here we examine the roles of WalRK and PhoPR in peptidoglycan metabolism in phosphate-limited cells. We show that B. subtilis cells remain viable in a phosphate-limited state for an extended period and resume growth rapidly upon phosphate addition, even in the absence of a PhoPR-mediated response. Peptidoglycan synthesis occurs in phosphate-limited wild-type cells at approximately 27% the rate of exponentially growing cells, and at approximately 18% the rate of exponentially growing cells in the absence of PhoPR. In phosphate-limited cells, the WalRK regulon genes yocH, cwlO(yvcE), lytE and ydjM are expressed in a manner that is dependent on the WalR recognition sequence and deleting these genes individually reduces the rate of peptidoglycan synthesis. We show that ydjM expression can be activated by PhoP approximately P in vitro and that PhoP occupies its promoter in phosphate-limited cells. However, iseA(yoeB) expression cannot be repressed by PhoP approximately P in vitro, but can be repressed by non-phosphorylated WalR in vitro. Therefore, we conclude that peptidoglycan metabolism is controlled by both WalRK and PhoPR in phosphate-limited B. subtilis cells.
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Affiliation(s)
- Paola Bisicchia
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
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39
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Abstract
We describe a primary high-throughput screen that uses the reporter strain Bacillus subtilis BAU-102 to identify antibiotics that induce autolysis. The screen measures autolysis in terms of the incipient release of recombinant Escherichia coli beta-galactosidase (beta-Gal) from the periplasmic space of B. subtilis owing to a loss of integrity of the cell wall. In a model screen, beta-Gal release values for 79 members of a library consisting of antibiotics and related compounds were collected, sorted, and plotted as a function of rank. Inducers of autolysis, which included compounds that inhibit cell wall synthesis and those that do not, were readily differentiated from other members of the library on the basis of their elevated beta-galactosidase release responses. The results of the BAU-102 model screen called attention to the antibacterial activity of drugs normally used in other applications, describable as "repurposed." Thus, the screen independently identified the potential antibacterial properties of the antifungal drug miconazole and of the antileishmaniasis drug miltefosine. Daptomycin-induced release of beta-Gal was also detected and occurred in a Ca(2+)-dependent manner.
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Deghorain M, Fontaine L, David B, Mainardi JL, Courtin P, Daniel R, Errington J, Sorokin A, Bolotin A, Chapot-Chartier MP, Hallet B, Hols P. Functional and morphological adaptation to peptidoglycan precursor alteration in Lactococcus lactis. J Biol Chem 2010; 285:24003-13. [PMID: 20525686 DOI: 10.1074/jbc.m110.143636] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cell wall peptidoglycan assembly is a tightly regulated process requiring the combined action of multienzyme complexes. In this study we provide direct evidence showing that substrate transformations occurring at the different stages of this process play a crucial role in the spatial and temporal coordination of the cell wall synthesis machinery. Peptidoglycan substrate alteration was investigated in the Gram-positive bacterium Lactococcus lactis by substituting the peptidoglycan precursor biosynthesis genes of this bacterium for those of the vancomycin-resistant bacterium Lactobacillus plantarum. A set of L. lactis mutant strains in which the normal d-Ala-ended precursors were partially or totally replaced by d-Lac-ended precursors was generated. Incorporation of the altered precursor into the cell wall induced morphological changes arising from a defect in cell elongation and cell separation. Structural analysis of the muropeptides confirmed that the activity of multiple enzymes involved in peptidoglycan synthesis was altered. Optimization of this altered pathway was necessary to increase the level of vancomycin resistance conferred by the utilization of d-Lac-ended peptidoglycan precursors in the mutant strains. The implications of these findings on the control of bacterial cell morphogenesis and the mechanisms of vancomycin resistance are discussed.
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Affiliation(s)
- Marie Deghorain
- Biochimie et Génétique Moléculaire Bactérienne, Institut des Sciences de la Vie, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
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Mutations in the Lipopolysaccharide biosynthesis pathway interfere with crescentin-mediated cell curvature in Caulobacter crescentus. J Bacteriol 2010; 192:3368-78. [PMID: 20435724 DOI: 10.1128/jb.01371-09] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial cell morphogenesis requires coordination among multiple cellular systems, including the bacterial cytoskeleton and the cell wall. In the vibrioid bacterium Caulobacter crescentus, the intermediate filament-like protein crescentin forms a cell envelope-associated cytoskeletal structure that controls cell wall growth to generate cell curvature. We undertook a genetic screen to find other cellular components important for cell curvature. Here we report that deletion of a gene (wbqL) involved in the lipopolysaccharide (LPS) biosynthesis pathway abolishes cell curvature. Loss of WbqL function leads to the accumulation of an aberrant O-polysaccharide species and to the release of the S layer in the culture medium. Epistasis and microscopy experiments show that neither S-layer nor O-polysaccharide production is required for curved cell morphology per se but that production of the altered O-polysaccharide species abolishes cell curvature by apparently interfering with the ability of the crescentin structure to associate with the cell envelope. Our data suggest that perturbations in a cellular pathway that is itself fully dispensable for cell curvature can cause a disruption of cell morphogenesis, highlighting the delicate harmony among unrelated cellular systems. Using the wbqL mutant, we also show that the normal assembly and growth properties of the crescentin structure are independent of its association with the cell envelope. However, this envelope association is important for facilitating the local disruption of the stable crescentin structure at the division site during cytokinesis.
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Pedersen MB, Zhou X, Larsen EKU, Sørensen US, Kjems J, Nygaard JV, Nyengaard JR, Meyer RL, Boesen T, Vorup-Jensen T. Curvature of synthetic and natural surfaces is an important target feature in classical pathway complement activation. THE JOURNAL OF IMMUNOLOGY 2010; 184:1931-45. [PMID: 20053940 DOI: 10.4049/jimmunol.0902214] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The binding of Abs to microbial surfaces followed by complement activation constitutes an important line of defense against infections. In this study, we have investigated the relationship between complement activation and the binding of human IgM Abs to surfaces with different curvatures. IgM Abs to dextran were shown to activate complement potently on dextran-coated particles having a diameter around 250 nm, whereas larger (600 nm) particles were less potent activators. This selectivity regarding particle dimension was also found for complement activation by colloidal substances of microbial origin. Peptidoglycan (PGN) is the major chemical component in the cell wall of Gram-positive bacteria. Fragments of purified PGN with sizes of approximately 100 nm promoted complement activation effectively through the classical pathway. By contrast, larger or smaller fragments of PGN did not activate complement strongly. A careful analysis of PGN fragments released during planctonic growth of Staphylococcus aureus showed that these include curvatures that would permit strong IgM-mediated complement activation, whereas the curvature of intact cells would be less effective for such activation. Consistently, we found that the suspended PGN fragments were strong activators of complement through the classical pathway. We suggest that these fragments act as decoy targets for complement activation, providing protection for S. aureus against the host immune response to infection.
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43
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Bramkamp M. The putative Bacillus subtilis L,D-transpeptidase YciB is a lipoprotein that localizes to the cell poles in a divisome-dependent manner. Arch Microbiol 2009; 192:57-68. [PMID: 20013255 DOI: 10.1007/s00203-009-0532-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/20/2009] [Accepted: 12/01/2009] [Indexed: 11/25/2022]
Abstract
Cell wall synthesis in bacteria is spatially organized by cytoskeletal structures. Common to all cell wall-bearing bacteria, the cytokinetic machinery localizes the cell wall synthesis to the site of septation. Recently, MinJ, a new component of the cytokinetic machinery, or divisome, of Bacillus subtilis has been described. MinJ is part of the division site selection system but also essential for correct assembly of the divisome. Here, I used the isolated PDZ domain of MinJ for co-elution experiments. One of the proteins that co-eluted was the so far uncharacterized, putative L,D-transpeptidase protein YciB. Evidence is shown that YciB localizes to the cell poles. YciB localization depends on the existence of a mature divisome, suggesting that L,D-transpeptidases are, like penicillin-binding proteins, part of the divisome.
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Affiliation(s)
- Marc Bramkamp
- Institute for Biochemistry, University of Cologne, Zülpicher Strasse 47, Cologne, Germany.
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44
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Kapoor S, Panda D. Targeting FtsZ for antibacterial therapy: a promising avenue. Expert Opin Ther Targets 2009; 13:1037-51. [DOI: 10.1517/14728220903173257] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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45
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Derman AI, Becker EC, Truong BD, Fujioka A, Tucey TM, Erb ML, Patterson PC, Pogliano J. Phylogenetic analysis identifies many uncharacterized actin-like proteins (Alps) in bacteria: regulated polymerization, dynamic instability and treadmilling in Alp7A. Mol Microbiol 2009; 73:534-52. [PMID: 19602153 DOI: 10.1111/j.1365-2958.2009.06771.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Actin, one of the most abundant proteins in the eukaryotic cell, also has an abundance of relatives in the eukaryotic proteome. To date though, only five families of actins have been characterized in bacteria. We have conducted a phylogenetic search and uncovered more than 35 highly divergent families of actin-like proteins (Alps) in bacteria. Their genes are found primarily on phage genomes, on plasmids and on integrating conjugative elements, and are likely to be involved in a variety of functions. We characterize three Alps and find that all form filaments in the cell. The filaments of Alp7A, a plasmid partitioning protein and one of the most divergent of the Alps, display dynamic instability and also treadmill. Alp7A requires other elements from the plasmid to assemble into dynamic polymers in the cell. Our findings suggest that most if not all of the Alps are indeed actin relatives, and that actin is very well represented in bacteria.
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Affiliation(s)
- Alan I Derman
- Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093-0377, USA
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Donovan C, Bramkamp M. Characterization and subcellular localization of a bacterial flotillin homologue. MICROBIOLOGY-SGM 2009; 155:1786-1799. [PMID: 19383680 DOI: 10.1099/mic.0.025312-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The process of endospore formation in Bacillus subtilis is complex, requiring the generation of two distinct cell types, a forespore and larger mother cell. The development of these cell types is controlled and regulated by cell type-specific gene expression, activated by a sigma-factor cascade. Activation of these cell type-specific sigma factors is coupled with the completion of polar septation. Here, we describe a novel protein, YuaG, a eukaryotic reggie/flotillin homologue that is involved in the early stages of sporulation of the Gram-positive model organism B. subtilis. YuaG localizes in discrete foci in the membrane and is highly dynamic. Purification of detergent-resistant membranes revealed that YuaG is associated with negatively charged phospholipids, e.g. phosphatidylglycerol (PG) or cardiolipin (CL). However, localization of YuaG is not always dependent on PG/CL in vivo. A yuaG disruption strain shows a delay in the onset of sporulation along with reduced sporulation efficiency, where the spores develop to a certain stage and then appear to be trapped at this stage. Our results indicate that YuaG is involved in the early stage of spore development, probably playing a role in the signalling cascade at the onset of sporulation.
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Affiliation(s)
- Catriona Donovan
- Institut für Biochemie, Universität zu Köln, Zülpicher Str. 47, D-50674 Köln, Germany
| | - Marc Bramkamp
- Institut für Biochemie, Universität zu Köln, Zülpicher Str. 47, D-50674 Köln, Germany
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Shiomi D, Sakai M, Niki H. Determination of bacterial rod shape by a novel cytoskeletal membrane protein. EMBO J 2008; 27:3081-91. [PMID: 19008860 DOI: 10.1038/emboj.2008.234] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Accepted: 10/15/2008] [Indexed: 11/09/2022] Open
Abstract
Cell shape is critical for growth, and some genes are involved in bacterial cell morphogenesis. Here, we report a novel gene, rodZ, required for the determination of rod shape in Escherichia coli. Cells lacking rodZ no longer had rod shape but rather were round or oval. These round cells were smaller than known round mutant cells, including mreB and pbpA mutants; both are known to lose rod shape. Morphogenesis from rod cells to round cells and vice versa, caused by depletion and overproduction of RodZ, respectively, revealed that RodZ could regulate the length of the long axis of the cell. RodZ is a membrane protein with bitopic topology such that the N-terminal region including a helix-turn-helix motif is in the cytoplasm, whereas the C-terminal region is exposed in the periplasm. GFP-RodZ forms spirals along the lateral axis of the cell beneath the cell membrane, similar to the MreB bacterial actin. Thus, RodZ may mediate spatial information from cytoskeletal proteins in the cytoplasm to a peptidoglycan synthesis machinery in the periplasm.
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Affiliation(s)
- Daisuke Shiomi
- Microbial Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, Mishima, Japan
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