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Chen Y, Zhang J, Zhu X, Wang Y, Chen J, Sui B, Teng HH. Unraveling the complexities of Cd-aniline composite pollution: Insights from standalone and joint toxicity assessments in a bacterial community. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 265:115509. [PMID: 37742573 DOI: 10.1016/j.ecoenv.2023.115509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 09/05/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023]
Abstract
Cadmium (Cd) and aniline frequently co-occur in industrial settings but have rarely been addressed as composite toxicants in terms of the overall toxicity despite extensive knowledge of the environmental impact of each individual pollutant. In this study, we attempt to assess the relation of individual and combined toxic effects of Cd and aniline using a bacterial consortium cultured from soils as a model system. Results showed that the consortial bacteria exhibited drastically stronger tolerance to stand-alone Cd and aniline in comparison to literature data acquired from single species studies. When occurring simultaneously, the joint toxicity displayed a concentration-dependent behavior that wasn't anticipated based on individual chemical tests. Specifically, additive effects manifested with Cd and aniline at their IC10s, but changed to synergistic when the concentrations increased to IC20, and finally transitioned into antagonistic at IC30s and beyond. In addition, co-occurring aniline appeared to have retarded the cellular accumulation of Cd while increasing the enzymatic activities of superoxide dismutase and catalase relative to that in Cd-alone treatments. Finally, the bacterial community experienced distinct compositional changes under solo and combined toxicities with several genera exhibiting inconsistent behavior between treatments of single and composite toxicants. Findings from this study highlight the complexity of bacterial response to composite pollutions and point to the need for more comprehensive references in risk and toxicology assessment at multi-chemical contamination sites.
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Affiliation(s)
- Yuxuan Chen
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 30072, China
| | - Jianchao Zhang
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 30072, China.
| | - Xiangyu Zhu
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 30072, China
| | - Yuebo Wang
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 30072, China
| | - Jiubin Chen
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 30072, China
| | - Biao Sui
- College of Resources and Environment, Jilin Agricultural University, Changchun 130118, China
| | - H Henry Teng
- School of Earth System Science, Institute of Surface-Earth System Science, Tianjin University, Tianjin 30072, China.
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2
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DivIVA Regulates Its Expression and the Orientation of New Septum Growth in Deinococcus radiodurans. J Bacteriol 2021; 203:e0016321. [PMID: 34031039 DOI: 10.1128/jb.00163-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In rod-shaped Gram-negative bacteria, FtsZ localization at midcell position is regulated by the gradient of MinCDE complex across the poles. In round-shaped bacteria, which lack predefined poles, the next plane of cell division is perpendicular to the previous plane, and determination of the FtsZ assembly site is still intriguing. Deinococcus radiodurans, a coccus bacterium, is characterized by its extraordinary resistance to DNA damage. DivIVA, a putative component of the Min system in this bacterium, interacts with cognate cell division and genome segregation proteins. Here, we report that deletion of a chromosomal copy of DivIVA was possible only when the wild-type copy of DivIVA was expressed in trans on a plasmid. However, deletion of the C-terminal domain (CTD) of DivIVA (CTD mutant) was possible but produced distinguishable phenotypes, like smaller cells, slower growth, and tilted septum orientation, in D. radiodurans. In trans expression of DivIVA in the CTD mutant could restore these features of the wild type. Interestingly, the overexpression of DivIVA led to delayed separation of tetrads from an octet state in both trans-complemented divIVA-mutant and wild-type cells. The CTD mutant showed upregulation of the yggS-divIVAN operon. Both the wild type and CTD mutant formed FtsZ foci; however, unlike wild type, the position of foci in the mutant cells was found to be away from conjectural midcell position in cocci. Notably, DivIVA-red fluorescent protein (DivIVA-RFP) localizes to the septum during cell division at the new division site. These results suggested that DivIVA is an essential protein in D. radiodurans, and its C-terminal domain plays an important role in the regulation of its expression and orientation of new septal growth in this bacterium. IMPORTANCE In rod-shaped Gram-negative bacteria, the midcell position for binary fission is relatively easy to model. In cocci that do not have predefined poles, the plane of next cell division is shown to be perpendicular to the previous plane. However, the molecular basis of perpendicularity is not known in cocci. The DivIVA protein of Deinococcus radiodurans, a coccus bacterium, physically interacts with the septum and establishes macromolecular interactions with genome segregation proteins through its N-terminal domain and with MinC through the C-terminal domain. Here, we have brought forth some evidence to suggest that DivIVA is essential for growth and plays an important role in cell polarity determination, and its C-terminal domain plays a crucial role in the growth of new septa in the correct orientation as well as in the regulation of DivIVA expression.
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Multiplex CRISPRi System Enables the Study of Stage-Specific Biofilm Genetic Requirements in Enterococcus faecalis. mBio 2020; 11:mBio.01101-20. [PMID: 33082254 PMCID: PMC7587440 DOI: 10.1128/mbio.01101-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Enterococcus faecalis causes multidrug-resistant life-threatening infections and is often coisolated with other pathogenic bacteria from polymicrobial biofilm-associated infections. Genetic tools to dissect complex interactions in mixed microbial communities are largely limited to transposon mutagenesis and traditional time- and labor-intensive allelic-exchange methods. Built upon streptococcal dCas9, we developed an easily modifiable, inducible CRISPRi system for E. faecalis that can efficiently silence single and multiple genes. This system can silence genes involved in biofilm formation and antibiotic resistance and can be used to interrogate gene essentiality. Uniquely, this tool is optimized to study genes important for biofilm initiation, maturation, and maintenance and can be used to perturb preformed biofilms. This system will be valuable to rapidly and efficiently investigate a wide range of aspects of complex enterococcal biology. Enterococcus faecalis is an opportunistic pathogen, which can cause multidrug-resistant life-threatening infections. Gaining a complete understanding of enterococcal pathogenesis is a crucial step in identifying a strategy to effectively treat enterococcal infections. However, bacterial pathogenesis is a complex process often involving a combination of genes and multilevel regulation. Compared to established knockout methodologies, CRISPR interference (CRISPRi) approaches enable the rapid and efficient silencing of genes to interrogate gene products and pathways involved in pathogenesis. As opposed to traditional gene inactivation approaches, CRISPRi can also be quickly repurposed for multiplexing or used to study essential genes. Here, we have developed a novel dual-vector nisin-inducible CRISPRi system in E. faecalis that can efficiently silence via both nontemplate and template strand targeting. Since the nisin-controlled gene expression system is functional in various Gram-positive bacteria, the developed CRISPRi tool can be extended to other genera. This system can be applied to study essential genes, genes involved in antimicrobial resistance, and genes involved in biofilm formation and persistence. The system is robust and can be scaled up for high-throughput screens or combinatorial targeting. This tool substantially enhances our ability to study enterococcal biology and pathogenesis, host-bacterium interactions, and interspecies communication.
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Induction of Daptomycin Tolerance in Enterococcus faecalis by Fatty Acid Combinations. Appl Environ Microbiol 2020; 86:AEM.01178-20. [PMID: 32801181 PMCID: PMC7531955 DOI: 10.1128/aem.01178-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/08/2020] [Indexed: 12/14/2022] Open
Abstract
With an increasing prevalence of antibiotic resistance in the clinic, we strive to understand more about microbial defensive mechanisms. A nongenetic tolerance to the antibiotic daptomycin was discovered in Enterococcus faecalis that results in the increased survival of bacterial populations after treatment with the drug. This tolerance mechanism likely synergizes with antibiotic resistance in the clinic. Given that this tolerance phenotype is induced by incorporation of fatty acids present in the host, it can be assumed that infections by this organism require a higher dose of antibiotic for successful eradication. The mixture of fatty acids in human fluids is quite diverse, with little understanding between the interplay of fatty acid combinations and the tolerance phenotype we observe. It is crucial to understand the effects of fatty acid combinations on E. faecalis physiology if we are to suppress the tolerance physiology in the clinic. Enterococcus faecalis is a Gram-positive bacterium that normally exists as an intestinal commensal in humans but is also a leading cause of nosocomial infections. Previous work noted that growth supplementation with serum induced tolerance to membrane-damaging agents, including the antibiotic daptomycin. Specific fatty acids found within serum could independently provide tolerance to daptomycin (protective fatty acids), yet some fatty acids found in serum did not and had negative effects on enterococcal physiology (nonprotective fatty acids). Here, we measured a wide array of physiological responses after supplementation with combinations of protective and nonprotective fatty acids to better understand how serum induces daptomycin tolerance. When cells were supplemented with either nonprotective fatty acid, palmitic acid, or stearic acid, there were marked defects in growth and morphology, but these defects were rescued upon supplementation with either protective fatty acid, oleic acid, or linoleic acid. Membrane fluidity decreased with growth in either palmitic or stearic acid alone but returned to basal levels when a protective fatty acid was supplied. Daptomycin tolerance could be induced if a protective fatty acid was provided with a nonprotective fatty acid, and some specific combinations protected as well as serum supplementation. While cell envelope charge has been associated with tolerance to daptomycin in other Gram-positive bacteria, we concluded that it does not correlate with the fatty acid-induced protection we observed. Based on these observations, we conclude that daptomycin tolerance by serum is driven by specific, protective fatty acids found within the fluid. IMPORTANCE With an increasing prevalence of antibiotic resistance in the clinic, we strive to understand more about microbial defensive mechanisms. A nongenetic tolerance to the antibiotic daptomycin was discovered in Enterococcus faecalis that results in the increased survival of bacterial populations after treatment with the drug. This tolerance mechanism likely synergizes with antibiotic resistance in the clinic. Given that this tolerance phenotype is induced by incorporation of fatty acids present in the host, it can be assumed that infections by this organism require a higher dose of antibiotic for successful eradication. The mixture of fatty acids in human fluids is quite diverse, with little understanding between the interplay of fatty acid combinations and the tolerance phenotype we observe. It is crucial to understand the effects of fatty acid combinations on E. faecalis physiology if we are to suppress the tolerance physiology in the clinic.
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5
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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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6
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Milner DS, Ray LJ, Saxon EB, Lambert C, Till R, Fenton AK, Sockett RE. DivIVA Controls Progeny Morphology and Diverse ParA Proteins Regulate Cell Division or Gliding Motility in Bdellovibrio bacteriovorus. Front Microbiol 2020; 11:542. [PMID: 32373080 PMCID: PMC7186360 DOI: 10.3389/fmicb.2020.00542] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/12/2020] [Indexed: 01/12/2023] Open
Abstract
The predatory bacterium B. bacteriovorus grows and divides inside the periplasm of Gram-negative bacteria, forming a structure known as a bdelloplast. Cell division of predators inside the dead prey cell is not by binary fission but instead by synchronous division of a single elongated filamentous cell into odd or even numbers of progeny cells. Bdellovibrio replication and cell division processes are dependent on the finite level of nutrients available from inside the prey bacterium. The filamentous growth and division process of the predator maximizes the number of progeny produced by the finite nutrients in a way that binary fission could not. To learn more about such an unusual growth profile, we studied the role of DivIVA in the growing Bdellovibrio cell. This protein is well known for its link to polar cell growth and spore formation in Gram-positive bacteria, but little is known about its function in a predatory growth context. We show that DivIVA is expressed in the growing B. bacteriovorus cell and controls cell morphology during filamentous cell division, but not the number of progeny produced. Bacterial Two Hybrid (BTH) analysis shows DivIVA may interact with proteins that respond to metabolic indicators of amino-acid biosynthesis or changes in redox state. Such changes may be relevant signals to the predator, indicating the consumption of prey nutrients within the sealed bdelloplast environment. ParA, a chromosome segregation protein, also contributes to bacterial septation in many species. The B. bacteriovorus genome contains three ParA homologs; we identify a canonical ParAB pair required for predatory cell division and show a BTH interaction between a gene product encoded from the same operon as DivIVA with the canonical ParA. The remaining ParA proteins are both expressed in Bdellovibrio but are not required for predator cell division. Instead, one of these ParA proteins coordinates gliding motility, changing the frequency at which the cells reverse direction. Our work will prime further studies into how one bacterium can co-ordinate its cell division with the destruction of another bacterium that it dwells within.
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Affiliation(s)
- David S Milner
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Luke J Ray
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Emma B Saxon
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Carey Lambert
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Rob Till
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Andrew K Fenton
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Renee Elizabeth Sockett
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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7
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Dehbashi S, Tahmasebi H, Sedighi P, Davarian F, Arabestani MR. Development of high-resolution melting curve analysis in rapid detection of vanA gene, Enterococcus faecalis, and Enterococcus faecium from clinical isolates. Trop Med Health 2020; 48:8. [PMID: 32099522 PMCID: PMC7027104 DOI: 10.1186/s41182-020-00197-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/10/2020] [Indexed: 12/18/2022] Open
Abstract
Background High-resolution melting analysis (HRMA) is a novel molecular technique based on the real-time PCR that can be used to detect vancomycin resistance Enterococcus (VRE). The purpose of this study was to identify VRE species with HRMA in clinical isolates. Results Out of 49 Enterococcus isolates, 11 (22.44%) E. faecium isolates and 19 (38.77%) E. faecalis isolates were detected. Average melting temperatures for divIVA in E.faecalis, alanine racemase in E.faecium, and vanA in VRE strains were obtained as 79.9 ± 0.5 °C, 85.4 ± 0.5 °C, and 82.99 ± 0.5 °C, respectively. Furthermore, the data showed that the HRMA method was sensitive to detect 100 CFU/ml for the divIVA, alanine racemase, and vanA genes. Also, out of 49 Enterococcus spp., which were isolated by HRMA assay, 8 isolates (16.32%) of E. faecium and 18 isolates (36.73%) of E. faecalis were detected. The vanA gene was reported in 2 isolates (25%) of E. faecium and 9 isolates (50%) of E. faecalis. Conclusions This study demonstrated that using the HRMA method, we can detect E. faecium, E. faecalis, and the vanA gene with high sensitivity and specificity.
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Affiliation(s)
- Sanaz Dehbashi
- 1Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Pajoohesh junction, Hamadan, Iran
| | - Hamed Tahmasebi
- 2Department of Microbiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | | | - Faeze Davarian
- 4School of Paramedical, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Reza Arabestani
- 1Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Pajoohesh junction, Hamadan, Iran.,5Nutritious Research Center, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
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Sharma K, Sultana T, Liao M, Dahms TES, Dillon JAR. EF1025, a Hypothetical Protein From Enterococcus faecalis, Interacts With DivIVA and Affects Cell Length and Cell Shape. Front Microbiol 2020; 11:83. [PMID: 32117116 PMCID: PMC7028823 DOI: 10.3389/fmicb.2020.00083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/15/2020] [Indexed: 01/22/2023] Open
Abstract
DivIVA plays multifaceted roles in Gram-positive organisms through its association with various cell division and non-cell division proteins. We report a novel DivIVA interacting protein in Enterococcus faecalis, named EF1025 (encoded by EF1025), which is conserved in Gram-positive bacteria. The interaction of EF1025 with DivIVAEf was confirmed by Bacterial Two-Hybrid, Glutathione S-Transferase pull-down, and co-immunoprecipitation assays. EF1025, which contains a DNA binding domain and two Cystathionine β-Synthase (CBS) domains, forms a decamer mediated by the two CBS domains. Viable cells were recovered after insertional inactivation or deletion of EF1025 only through complementation of EF1025 in trans. These cells were longer than the average length of E. faecalis cells and had distorted shapes. Overexpression of EF1025 also resulted in cell elongation. Immuno-staining revealed comparable localization patterns of EF1025 and DivIVAEf in the later stages of division in E. faecalis cells. In summary, EF1025 is a novel DivIVA interacting protein influencing cell length and morphology in E. faecalis.
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Affiliation(s)
- Kusum Sharma
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Taranum Sultana
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Mingmin Liao
- Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Jo-Anne R Dillon
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization - International Vaccine Centre, University of Saskatchewan, Saskatoon, SK, Canada
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Abstract
Reproduction in the bacterial kingdom predominantly occurs through binary fission-a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped Escherichia coli and Bacillus subtilis, which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.
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10
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Chaudhary R, Gupta A, Kota S, Misra HS. N-terminal domain of DivIVA contributes to its dimerization and interaction with genome segregation proteins in a radioresistant bacterium Deinococcus radiodurans. Int J Biol Macromol 2019; 128:12-21. [PMID: 30682467 DOI: 10.1016/j.ijbiomac.2019.01.085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/13/2019] [Accepted: 01/19/2019] [Indexed: 01/27/2023]
Abstract
Unlike in rod-shaped bacteria, cell polarity is not well defined in cocci and possibly gets marked during molecular events around cytokinesis. DivIVA is a member of Min system that is involved in spatial regulation of septum formation in bacteria. Recently, we showed that DivIVA of Deinococcus radiodurans (drDivIVA) interacts with proteins involved in cell division and genome segregation (segrosome). To map drDivIVA domain (s) that interact with these proteins, the N-terminal (DivIVA-N), C-terminal (DivIVA-C) and a middle (DivIVA-M) region/section of drDivIVA were generated. Circular Dichroism (CD) studies suggested that all three variants of drDivIVA fold properly, but they appeared different under transmission electron microscopy (TEM). Full length drDivIVA showed bundles under TEM whereas variants did not. Both full length drDivIVA and N-terminal domain showed repeats of heptad motifs, a characteristic of alpha-helical coiled-coil proteins. DivIVA-N showed dimerization and interaction with segrosome while DivIVA-M interacted with MinC, a cell division regulatory protein. Further, the C-terminal region seems to be crucial for the structural and functional integrity of drDivIVA. These results suggested that drDivIVA dimerizes through its N-terminal domain while both segrosome and MinC interact through different regions of this protein.
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Affiliation(s)
- Reema Chaudhary
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Life Sciences, Homi Bhabha National Institute, Mumbai 400094, India
| | - Alka Gupta
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Swathi Kota
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Life Sciences, Homi Bhabha National Institute, Mumbai 400094, India
| | - H S Misra
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Life Sciences, Homi Bhabha National Institute, Mumbai 400094, India.
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Tharsius Raja WR, Antony S, Pachaiyappan S, Amalraj J, Narasimhan P, Keduki B, Veeramuthu D, Perumal P, Savarimuthu I. Antibacterial Activity study of Musizin isolated from Rhamnus wightii Wight and Arn. Bioinformation 2018; 14:511-520. [PMID: 31223211 PMCID: PMC6563663 DOI: 10.6026/97320630014511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/03/2018] [Accepted: 12/03/2018] [Indexed: 11/27/2022] Open
Abstract
The crude extracts and the compounds isolated from traditional medicinal plants are used to treat infectious diseases caused by bacteria,
fungi, and viruses. An attempt has been made in the present investigation to evaluate the antibacterial activity of musizin isolated from
Rhamnus wightii, (Family: Rhamnaceae) against Gram-positive (Bacillus cereus, Staphylococcus aureus, Streptococcus faecalis), and Gramnegative
(Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa) bacteria. The tested compound showed more pronounced
antibacterial activity against the tested pathogens than the standard antibiotics like streptomycin and gentamycin with the lowest
minimum inhibitory concentration (MIC). Molecular docking analysis was performed to study the effectiveness of musizin compared to
the standard antibiotics; it showed a significant interaction with the target proteins such asalgR (P. arginosa), divIVA (E. faecalis), icaA (S.
aureus), plcR(B. cereus), treC (K. pneumonia) and ftsl (E. coli) and found that musizin showed higher potential with least binding energy. It has
also been found that musizin had better ADMET properties than the standard drugs. Thus,musizin acts as an inhibitor of bacterial growth
for consideration as a drug to treat bacterial infections.
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Affiliation(s)
| | - Stalin Antony
- 2Division of Bioinformatics,Entomology Research Institute, Loyola College, Chennai.,Centre of Advanced Studies in Botany and Centre for Herbal Sciences,University of Madras, Guindy Campus, Chennai 600 025, India
| | | | - Jackson Amalraj
- Division of Microbiology, Entomology Research Institute, LoyolaCollege, Chennai - Chennai
| | - Poorva Narasimhan
- Centre of Advanced Studies in Botany and Centre for Herbal Sciences,University of Madras, Guindy Campus, Chennai 600 025, India
| | - Balakrishna Keduki
- Division of Ethnopharmacology, Entomology Research Institute, Loyola College, Chennai
| | - Duraipandiyan Veeramuthu
- Division of Microbiology, Entomology Research Institute, LoyolaCollege, Chennai - Chennai.,Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies Collegeof Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Palani Perumal
- Centre of Advanced Studies in Botany and Centre for Herbal Sciences,University of Madras, Guindy Campus, Chennai 600 025, India
| | - Ignacimuthu Savarimuthu
- Division of Ethnopharmacology, Entomology Research Institute, Loyola College, Chennai.,International Scientific Partnership Program, King Saud University, PostBox 2455, Riyadh 1011 11451, Kingdom of Saudi Arabia
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12
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Melzer ES, Sein CE, Chambers JJ, Siegrist MS. DivIVA concentrates mycobacterial cell envelope assembly for initiation and stabilization of polar growth. Cytoskeleton (Hoboken) 2018; 75:498-507. [PMID: 30160378 PMCID: PMC6644302 DOI: 10.1002/cm.21490] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/07/2018] [Accepted: 06/27/2018] [Indexed: 12/31/2022]
Abstract
In many model organisms, diffuse patterning of cell wall peptidoglycan synthesis by the actin homolog MreB enables the bacteria to maintain their characteristic rod shape. In Caulobacter crescentus and Escherichia coli, MreB is also required to sculpt this morphology de novo. Mycobacteria are rod-shaped but expand their cell wall from discrete polar or subpolar zones. In this genus, the tropomyosin-like protein DivIVA is required for the maintenance of cell morphology. DivIVA has also been proposed to direct peptidoglycan synthesis to the tips of the mycobacterial cell. The precise nature of this regulation is unclear, as is its role in creating rod shape from scratch. We find that DivIVA localizes nascent cell wall and covalently associated mycomembrane but is dispensable for the assembly process itself. Mycobacterium smegmatis rendered spherical by peptidoglycan digestion or by DivIVA depletion are able to regain rod shape at the population level in the presence of DivIVA. At the single cell level, there is a close spatiotemporal correlation between DivIVA foci, rod extrusion and concentrated cell wall synthesis. Thus, although the precise mechanistic details differ from other organisms, M. smegmatis also establish and propagate rod shape by cytoskeleton-controlled patterning of peptidoglycan. Our data further support the emerging notion that morphology is a hardwired trait of bacterial cells.
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Affiliation(s)
- Emily S Melzer
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
| | - Caralyn E Sein
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
| | - James J Chambers
- Institute for Applied Life Sciences, University of Massachusetts, Amherst, Massachusetts
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts.,Molecular and Cellular Biology, University of Massachusetts, Amherst, Massachusetts
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13
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Sharma D, Khan AU. Role of cell division protein divIVA in Enterococcus faecalis pathogenesis, biofilm and drug resistance: A future perspective by in silico approaches. Microb Pathog 2018; 125:361-365. [PMID: 30290265 DOI: 10.1016/j.micpath.2018.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/01/2018] [Accepted: 10/01/2018] [Indexed: 12/18/2022]
Abstract
Antibiotics resistance is the major problem in clinical settings which leads to the emergence of drug resistant bacteria. Biofilm formation is one of the grounds for the emergence of antibiotics resistant strains of Enterococcus faecalis. Our group previously reported in a comparative proteomic study of biofilm and planktonic state of E. faecalis that cell division protein divIVA was two folds overexpressed in biofilm state as compared to planktonic one and suggested its involvement in biofilm formation and antibiotics resistance. In this in silico study molecular docking showed that DNA bind to the conserved amino acid residues of divIVA domain and suggested that divIVA possibly secretes DNA into extra polymeric substance (EPS) which is the part of biofilm. We also performed the STRING analysis of cell division protein divIVA and predicted their interactive partners {cell division proteins/divisome complex (ftsZ, ftsA, divIV, ftsL, & gpsB), hypothetical proteins (sepF, EF_0261, EF_1000, EF_0998, EF_1006 & EF_1040), isoleucyl-tRNA synthetase (ileS), septation ring formation regulator (ezrA), S4 domain-containing protein (EF_1001), rod shape-determining protein (mreC), UDP-N-acetylmuramoyl-L-alanyl-d-glutamate synthetase (murD), UDP-diphospho-muramoyl-pentapeptide beta-N- acetylglucosaminyltransferase (murG), Lipoprotein signal peptidase (lspA), adenylate kinase (adk) and DNA-binding response regulator (vicR)}. We suggest that cumulatively divIVA and its interactive partners might be directly or indirectly involved in E. faecalis cell division, growth, biofilm formation, virulence and resistance.
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Affiliation(s)
- Divakar Sharma
- Medical Microbiology and Molecular Biology Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India
| | - Asad U Khan
- Medical Microbiology and Molecular Biology Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India.
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14
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Ni H, Fan W, Li C, Wu Q, Hou H, Hu D, Zheng F, Zhu X, Wang C, Cao X, Shao ZQ, Pan X. Streptococcus suis DivIVA Protein Is a Substrate of Ser/Thr Kinase STK and Involved in Cell Division Regulation. Front Cell Infect Microbiol 2018; 8:85. [PMID: 29616196 PMCID: PMC5869912 DOI: 10.3389/fcimb.2018.00085] [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: 12/01/2017] [Accepted: 03/02/2018] [Indexed: 12/14/2022] Open
Abstract
Streptococcus suis serotype 2 is an important swine pathogen and an emerging zoonotic agent that causes severe infections. Recent studies have reported a eukaryotic-like Ser/Thr protein kinase (STK) gene and characterized its role in the growth and virulence of different S. suis 2 strains. In the present study, phosphoproteomic analysis was adopted to identify substrates of the STK protein. Seven proteins that were annotated to participate in different cell processes were identified as potential substrates, which suggests the pleiotropic effects of stk on S. suis 2 by targeting multiple pathways. Among them, a protein characterized as cell division initiation protein (DivIVA) was further investigated. In vitro analysis demonstrated that the recombinant STK protein directly phosphorylates threonine at amino acid position 199 (Thr-199) of DivIVA. This effect could be completely abolished by the T199A mutation. To determine the specific role of DivIVA in growth and division, a divIVA mutant was constructed. The ΔdivIVA strain exhibited impaired growth and division, including lower viability, enlarged cell mass, asymmetrical division caused by aberrant septum, and extremely weak pathogenicity in a mouse infection model. Collectively, our results reveal that STK regulates the cell growth and virulence of S. suis 2 by targeting substrates that are involved in different biological pathways. The inactivation of DivIVA leads to severe defects in cell division and strongly attenuates pathogenicity, thereby indicating its potential as a molecular drug target against S. suis.
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Affiliation(s)
- Hua Ni
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China.,School of Life Sciences, Nanjing Normal University, Nanjing, China.,The Key Laboratory of Ecology and Biological Resources in Yarkand Oasis at Colleges and Universities Under the Department of Education of Xinjiang Uygur Autonomous Region, Kashgar University, Kashgar, China
| | - Weiwei Fan
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China.,Department of Pharmacy, Changzhou Wujin People's Hospital, Changzhou, China
| | - Chaolong Li
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China.,School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qianqian Wu
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China
| | - Hongfen Hou
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China.,School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Dan Hu
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China
| | - Feng Zheng
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China
| | - Xuhui Zhu
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China
| | - Changjun Wang
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China
| | - Xiangrong Cao
- School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Zhu-Qing Shao
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China.,State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Xiuzhen Pan
- Department of Microbiology, Hua Dong Research Institute for Medicine and Biotechnics, Nanjing, China.,School of Life Sciences, Nanjing Normal University, Nanjing, China
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15
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Misra HS, Maurya GK, Chaudhary R, Misra CS. Interdependence of bacterial cell division and genome segregation and its potential in drug development. Microbiol Res 2018; 208:12-24. [DOI: 10.1016/j.micres.2017.12.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 12/05/2017] [Accepted: 12/31/2017] [Indexed: 11/28/2022]
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16
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Enterococcus faecalis Responds to Individual Exogenous Fatty Acids Independently of Their Degree of Saturation or Chain Length. Appl Environ Microbiol 2017; 84:AEM.01633-17. [PMID: 29079613 PMCID: PMC5734047 DOI: 10.1128/aem.01633-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/18/2017] [Indexed: 12/15/2022] Open
Abstract
Enterococcus faecalis is a commensal of the human gastrointestinal tract that can persist in the external environment and is a leading cause of hospital-acquired infections. Given its diverse habitats, the organism has developed numerous strategies to survive a multitude of environmental conditions. Previous studies have demonstrated that E. faecalis will incorporate fatty acids from bile and serum into its membrane, resulting in an induced tolerance to membrane-damaging agents. To discern whether all fatty acids induce membrane stress protection, we examined how E. faecalis responded to individually supplied fatty acids. E. faecalis readily incorporated fatty acids 14 to 18 carbons in length into its membrane but poorly incorporated fatty acids shorter or longer than this length. Supplementation with saturated fatty acids tended to increase generation time and lead to altered cellular morphology in most cases. Further, exogenously supplied saturated fatty acids did not induce tolerance to the membrane-damaging antibiotic daptomycin. Supplementation with unsaturated fatty acids produced variable growth effects, with some impacting generation time and morphology. Exogenously supplied unsaturated fatty acids that are normally produced by E. faecalis and those that are found in bile or serum could restore growth in the presence of a fatty acid biosynthetic inhibitor. However, only the eukaryote-derived fatty acids oleic acid and linoleic acid provided protection from daptomycin. Thus, exogenous fatty acids do not lead to a common physiological effect on E. faecalis. The organism responds uniquely to each, and only host-derived fatty acids induce membrane protection. IMPORTANCEEnterococcus faecalis is a commonly acquired hospital infectious agent with resistance to many antibiotics, including those that target its cellular membrane. We previously demonstrated that E. faecalis will incorporate fatty acids found in human fluids, like serum, into its cellular membrane, thereby altering its membrane composition. In turn, the organism is better able to survive membrane-damaging agents, including the antibiotic daptomycin. We examined fatty acids commonly found in serum and those normally produced by E. faecalis to determine which fatty acids can induce protection from membrane damage. Supplementation with individual fatty acids produced a myriad of different effects on cellular growth, morphology, and stress response. However, only host-derived unsaturated fatty acids provided stress protection. Future studies are aimed at understanding how these specific fatty acids induce protection from membrane damage.
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17
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Bottomley AL, Liew ATF, Kusuma KD, Peterson E, Seidel L, Foster SJ, Harry EJ. Coordination of Chromosome Segregation and Cell Division in Staphylococcus aureus. Front Microbiol 2017; 8:1575. [PMID: 28878745 PMCID: PMC5572376 DOI: 10.3389/fmicb.2017.01575] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 08/03/2017] [Indexed: 12/03/2022] Open
Abstract
Productive bacterial cell division and survival of progeny requires tight coordination between chromosome segregation and cell division to ensure equal partitioning of DNA. Unlike rod-shaped bacteria that undergo division in one plane, the coccoid human pathogen Staphylococcus aureus divides in three successive orthogonal planes, which requires a different spatial control compared to rod-shaped cells. To gain a better understanding of how this coordination between chromosome segregation and cell division is regulated in S. aureus, we investigated proteins that associate with FtsZ and the divisome. We found that DnaK, a well-known chaperone, interacts with FtsZ, EzrA and DivIVA, and is required for DivIVA stability. Unlike in several rod shaped organisms, DivIVA in S. aureus associates with several components of the divisome, as well as the chromosome segregation protein, SMC. This data, combined with phenotypic analysis of mutants, suggests a novel role for S. aureus DivIVA in ensuring cell division and chromosome segregation are coordinated.
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Affiliation(s)
- Amy L Bottomley
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Andrew T F Liew
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Kennardy D Kusuma
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Elizabeth Peterson
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Lisa Seidel
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
| | - Simon J Foster
- Department of Molecular Biology and Biotechnology, Krebs Institute, University of SheffieldSheffield, United Kingdom
| | - Elizabeth J Harry
- The ithree Institute, University of Technology Sydney, SydneyNSW, Australia
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18
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Qayyum S, Sharma D, Bisht D, Khan AU. Protein translation machinery holds a key for transition of planktonic cells to biofilm state in Enterococcus faecalis : A proteomic approach. Biochem Biophys Res Commun 2016; 474:652-659. [DOI: 10.1016/j.bbrc.2016.04.145] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 04/30/2016] [Indexed: 11/26/2022]
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19
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Rismondo J, Cleverley RM, Lane HV, Großhennig S, Steglich A, Möller L, Mannala GK, Hain T, Lewis RJ, Halbedel S. Structure of the bacterial cell division determinant GpsB and its interaction with penicillin-binding proteins. Mol Microbiol 2015; 99:978-98. [PMID: 26575090 DOI: 10.1111/mmi.13279] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2015] [Indexed: 01/05/2023]
Abstract
Each bacterium has to co-ordinate its growth with division to ensure genetic stability of the population. Consequently, cell division and growth are tightly regulated phenomena, albeit different bacteria utilise one of several alternative regulatory mechanisms to maintain control. Here we consider GpsB, which is linked to cell growth and division in Gram-positive bacteria. ΔgpsB mutants of the human pathogen Listeria monocytogenes show severe lysis, division and growth defects due to distortions of cell wall biosynthesis. Consistent with this premise, GpsB interacts both in vitro and in vivo with the major bi-functional penicillin-binding protein. We solved the crystal structure of GpsB and the interaction interfaces in both proteins are identified and validated. The inactivation of gpsB results in strongly attenuated virulence in animal experiments, comparable in degree to classical listerial virulence factor mutants. Therefore, GpsB is essential for in vitro and in vivo growth of a highly virulent food-borne pathogen, suggesting that GpsB could be a target for the future design of novel antibacterials.
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Affiliation(s)
- Jeanine Rismondo
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Robert M Cleverley
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Harriet V Lane
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Stephanie Großhennig
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany.,Department of General Microbiology, Institute of Microbiology and Genetics, Georg-August University, Göttingen, Germany
| | - Anne Steglich
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Lars Möller
- ZBS 4 - Advanced Light and Electron Microscopy, Robert Koch Institute, Berlin, Germany
| | | | - Torsten Hain
- Institute of Medical Microbiology, University of Gießen, Gießen, Germany
| | - Richard J Lewis
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, UK
| | - Sven Halbedel
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
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20
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Castellen P, Sforça ML, Gueiros-Filho FJ, de Mattos Zeri AC. Backbone and side chain NMR assignments for the N-terminal domain of the cell division regulator MinC from Bacillus subtilis. BIOMOLECULAR NMR ASSIGNMENTS 2015; 9:1-5. [PMID: 24366721 DOI: 10.1007/s12104-013-9534-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 12/12/2013] [Indexed: 06/03/2023]
Abstract
Bacterial cell division proteins must assemble at the middle of the cell to ensure the viability of both daughter cells. The first step in the assembly of the cell division apparatus is the polymerization of the tubulin-like protein FtsZ into a ring-shaped scaffold, the Z-ring. The Min system contributes to the spatial precision of division by inhibiting FtsZ polymerization at the cell poles. The component of this system that interacts with FtsZ is MinC, a 25 kDa protein that has two domains. The N-terminal domain of MinC is the main responsible for FtsZ inhibition, being sufficient to block Z-ring assembly when overexpressed in vivo, and to inhibit FtsZ polymerization in vitro. Despite intensive studies, little is known about the MinC binding site for FtsZ. We have assigned the backbone and side chain resonances of the MinC N-terminal domain of Bacillus subtilis through NMR spectroscopy. These assignments provide the basis to characterize the interaction between the N-terminal domain of MinC and FtsZ by NMR methods.
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Affiliation(s)
- Patricia Castellen
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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21
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How to get (a)round: mechanisms controlling growth and division of coccoid bacteria. Nat Rev Microbiol 2013; 11:601-14. [PMID: 23949602 DOI: 10.1038/nrmicro3088] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Bacteria come in a range of shapes, including round, rod-shaped, curved and spiral cells. This morphological diversity implies that different mechanisms exist to guide proper cell growth, division and chromosome segregation. Although the majority of studies on cell division have focused on rod-shaped cells, the development of new genetic and cell biology tools has provided mechanistic insight into the cell cycles of bacteria with different shapes, allowing us to appreciate the underlying molecular basis for their morphological diversity. In this Review, we discuss recent progress that has advanced our knowledge of the complex mechanisms for chromosome segregation and cell division in bacteria which have, deceptively, the simplest possible shape: the cocci.
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22
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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: 114] [Impact Index Per Article: 10.4] [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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23
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Blasios V, Bisson-Filho AW, Castellen P, Nogueira MLC, Bettini J, Portugal RV, Zeri ACM, Gueiros-Filho FJ. Genetic and biochemical characterization of the MinC-FtsZ interaction in Bacillus subtilis. PLoS One 2013; 8:e60690. [PMID: 23577149 PMCID: PMC3618327 DOI: 10.1371/journal.pone.0060690] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 03/01/2013] [Indexed: 11/22/2022] Open
Abstract
Cell division in bacteria is regulated by proteins that interact with FtsZ and modulate its ability to polymerize into the Z ring structure. The best studied of these regulators is MinC, an inhibitor of FtsZ polymerization that plays a crucial role in the spatial control of Z ring formation. Recent work established that E. coli MinC interacts with two regions of FtsZ, the bottom face of the H10 helix and the extreme C-terminal peptide (CTP). Here we determined the binding site for MinC on Bacillus subtilis FtsZ. Selection of a library of FtsZ mutants for survival in the presence of Min overexpression resulted in the isolation of 13 Min-resistant mutants. Most of the substitutions that gave rise to Min resistance clustered around the H9 and H10 helices in the C-terminal domain of FtsZ. In addition, a mutation in the CTP of B. subtilis FtsZ also produced MinC resistance. Biochemical characterization of some of the mutant proteins showed that they exhibited normal polymerization properties but reduced interaction with MinC, as expected for binding site mutations. Thus, our study shows that the overall architecture of the MinC-FtsZ interaction is conserved in E. coli and B. subtilis. Nevertheless, there was a clear difference in the mutations that conferred Min resistance, with those in B. subtilis FtsZ pointing to the side of the molecule rather than to its polymerization interface. This observation suggests that the mechanism of Z ring inhibition by MinC differs in both species.
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Affiliation(s)
- Valdir Blasios
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | | | - Patricia Castellen
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
- Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Maria Luiza C. Nogueira
- Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Jefferson Bettini
- Nanotechnology National Laboratory (LNNano), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Rodrigo V. Portugal
- Nanotechnology National Laboratory (LNNano), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
| | - Ana Carolina M. Zeri
- Brazilian Biosciences National Laboratory (LNBio), Centro Nacional de Pesquisas em Energia e Materiais (CNPEM), Campinas, Brasil
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25
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Massier S, Bouffartigues E, Rincé A, Maillot O, Feuilloley MGJ, Orange N, Chevalier S. Effects of a pulsed light-induced stress on Enterococcus faecalis. J Appl Microbiol 2012; 114:186-95. [PMID: 23035907 DOI: 10.1111/jam.12029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 09/16/2012] [Accepted: 09/25/2012] [Indexed: 01/28/2023]
Abstract
AIMS Pulsed light (PL) technology is a surface decontamination process that can be used on food, packaging or water. PL efficiency may be limited by its low degree of penetration or because of a shadow effect. In these cases, surviving bacteria will be able to perceive PL as a stress. Such a stress was mimicked using low transmitted energy conditions, and its effects were investigated on the highly environmental adaptable bacterium Enterococcus faecalis V583. METHODS AND RESULTS In these laboratory conditions, a complete decontamination of the artificially inoculated medium was performed using energy doses as low as 1.8 J cm(-2) , while a treatment of 0.5, 1 and 1.2 J cm(-2) led to a 2.2, 6 and 7-log(10) CFU ml(-1) reduction in the initial bacterial population, respectively. Application of a 0.5 J cm(-2) pretreatment allowed the bacteria to resist more efficiently a 1.2 J cm(-2) subsequent PL dose. This 0.5 J cm(-2) treatment increased the bacterial mutation frequency and affected the abundance of 19 proteins as revealed by a global proteome analysis. CONCLUSIONS Enterococcus faecalis is able to adapt to a PL treatment, providing a molecular response to low-energy PL dose, leading to enhanced resistance to a subsequent treatment and increasing the mutation frequency. SIGNIFICANCE AND IMPACT OF THE STUDY This study gives further insights on Ent. faecalis capacities to adapt and to resist to stress.
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Affiliation(s)
- S Massier
- LMSM, Laboratoire de Microbiologie-Signaux et Microenvironnement, EA 4312, Université de Rouen, Evreux, France
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26
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SalB inactivation modulates culture supernatant exoproteins and affects autolysis and viability in Enterococcus faecalis OG1RF. J Bacteriol 2012; 194:3569-78. [PMID: 22563054 DOI: 10.1128/jb.00376-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The culture supernatant fraction of an Enterococcus faecalis gelE mutant of strain OG1RF contained elevated levels of the secreted antigen SalB. Using differential fluorescence gel electrophoresis (DIGE) the salB mutant was shown to possess a unique complement of exoproteins. Differentially abundant exoproteins were identified using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Stress-related proteins including DnaK, Dps family protein, SOD, and NADH peroxidase were present in greater quantity in the OG1RF salB mutant culture supernatant. Moreover, several proteins involved in cell wall synthesis and cell division, including d-Ala-d-Lac ligase and EzrA, were present in reduced quantity in OG1RF salB relative to the parent strain. The salB mutant displayed reduced viability and anomalous cell division, and these phenotypes were exacerbated in a gelE salB double mutant. An epistatic relationship between gelE and salB was not identified with respect to increased autolysis and cell morphological changes observed in the salB mutant. SalB was purified as a six-histidine-tagged protein to investigate peptidoglycan hydrolytic activity; however, activity was not evident. High-pressure liquid chromatography (HPLC) analysis of reduced muropeptides from peptidoglycan digested with mutanolysin revealed that the salB mutant and OG1RF were indistinguishable.
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27
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Raz A, Talay SR, Fischetti VA. Cellular aspects of the distinct M protein and SfbI anchoring pathways in Streptococcus pyogenes. Mol Microbiol 2012; 84:631-47. [PMID: 22512736 DOI: 10.1111/j.1365-2958.2012.08047.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Wall-anchored surface proteins are critical for the in vivo survival of Streptococcus pyogenes. Cues in the signal sequence direct the membrane translocation of surface proteins: M protein to the septum, and SfbI to the poles. Both proteins are subsequently anchored to the wall by the membrane bound enzyme sortase A. However, the cellular features of these pathways are not fully understood. Here we show that M protein and SfbI are anchored simultaneously throughout the cell cycle. M protein is rapidly anchored at the septum, and in part of the cell cycle, is anchored simultaneously at the mother and daughter septa. Conversely, SfbI accumulates gradually on peripheral peptidoglycan, resulting in a polar distribution. Sortase is not required for translocation of M protein or SfbI at their respective locations. Methicillin-induced unbalanced peptidoglycan synthesis diminishes surface M protein but not SfbI. Furthermore, overexpression of the division regulator DivIVA also diminishes surface M protein but increases SfbI. These results demonstrate a close connection between the regulation of cell division and protein anchoring. Better understanding of the spatial regulation of surface anchoring may lead to the identification of novel targets for the development of anti-infective agents, given the importance of surface molecules for pathogenesis.
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Affiliation(s)
- Assaf Raz
- Bacterial Pathogenesis and Immunology, Rockefeller University, New York, USA.
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28
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Shankar J, Walker RG, Ward D, Horsburgh MJ. The Enterococcus faecalis exoproteome: identification and temporal regulation by Fsr. PLoS One 2012; 7:e33450. [PMID: 22428053 PMCID: PMC3299793 DOI: 10.1371/journal.pone.0033450] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/13/2012] [Indexed: 01/18/2023] Open
Abstract
Analysis of the culture supernatant exoproteins produced by two PFGE clusters of high-level gentamicin and ciprofloxacin-resistant clinical isolates of Enterococcus faecalis from the UK and Ireland revealed two distinct protein profiles. This grouping distinguished OG1RF and GelE metalloprotease-expressing isolates from JH2-2 and other GelE-negative isolates. The integrity of the fsrABDC operon was found to determine the exoproteome composition, since an fsrB mutant of strain OG1RF appeared very similar to that of strain JH2-2, and complementation of the latter with the fsrABDC operon produced an OG1RF-like exoproteome. The proteins present in the supernatant fraction of OG1RF were separated using 2D gels and identified by mass spectrometry and comprised many mass and pI variants of the GelE and SprE proteases. In addition cell wall synthesis and cell division proteins were identified. An OG1RF fsrB mutant had a distinct exoprotein fraction with an absence of the Fsr-regulated proteases and was characterised by general stress and glycolytic proteins. The exoproteome of the OG1RF fsrB mutant resembles that of a divIVA mutant of E. faecalis, suggestive of a stress phenotype.
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Affiliation(s)
| | | | | | - Malcolm J. Horsburgh
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
- * E-mail:
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Donovan C, Sieger B, Krämer R, Bramkamp M. A synthetic Escherichia coli system identifies a conserved origin tethering factor in Actinobacteria. Mol Microbiol 2012; 84:105-16. [DOI: 10.1111/j.1365-2958.2012.08011.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Halbedel S, Hahn B, Daniel RA, Flieger A. DivIVA affects secretion of virulence-related autolysins in Listeria monocytogenes. Mol Microbiol 2012; 83:821-39. [PMID: 22353466 DOI: 10.1111/j.1365-2958.2012.07969.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DivIVA is a well-conserved coiled-coil protein present in most Gram-positive bacteria and has been implicated in division site selection, peptidoglycan biosynthesis and sporulation. DivIVA proteins bind lipid membranes and characteristically accumulate at curved membrane areas, i.e. the cell poles and the division site, to which they recruit various interaction partners. We have studied the role of this morphogen in the human pathogen Listeria monocytogenes and our results suggest a novel mechanism by which DivIVA contributes to cell division. Contrary to expectation a ΔdivIVA mutant exhibited a pronounced chaining phenotype rather than a defect in cell division which we attributed to reduced extracellular levels of the autolytic enzymes p60 and MurA. We demonstrate that this is due to a malfunction in secretion of these autolysins and phenotypic comparison of the ΔdivIVA strain with a ΔsecA2 mutant suggests that DivIVA influences the activity of the SecA2 secretion route in L. monocytogenes. Also from the phenotypic analysis it was clear that divIVA affected swarming motility, biofilm formation, invasiveness and cell-to-cell spread in cell culture infection models. Thus, our experiments show that DivIVA is an important factor for various listerial traits that are essential for the pathogenicity of this organism.
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Affiliation(s)
- Sven Halbedel
- Robert Koch Institute, FG11 - Division of Bacterial Infections, Burgstrasse 37, 38855 Wernigerode, Germany.
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Transcriptome, proteome, and metabolite analyses of a lactate dehydrogenase-negative mutant of Enterococcus faecalis V583. Appl Environ Microbiol 2011; 77:2406-13. [PMID: 21296946 DOI: 10.1128/aem.02485-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A constructed lactate dehydrogenase (LDH)-negative mutant of Enterococcus faecalis V583 grows at the same rate as the wild type but ferments glucose to ethanol, formate, and acetoin. Microarray analysis showed that LDH deficiency had profound transcriptional effects: 43 genes in the mutant were found to be upregulated, and 45 were found to be downregulated. Most of the upregulated genes encode enzymes of energy metabolism or transport. By two-dimensional (2D) gel analysis, 45 differentially expressed proteins were identified. A comparison of transcriptomic and proteomic data suggested that for several proteins the level of expression is regulated beyond the level of transcription. Pyruvate catabolic genes, including the truncated ldh gene, showed highly increased transcription in the mutant. These genes, along with a number of other differentially expressed genes, are preceded by sequences with homology to binding sites for the global redox-sensing repressor, Rex, of Staphylococcus aureus. The data indicate that the genes are transcriptionally regulated by the NADH/NAD ratio and that this ratio plays an important role in the regulatory network controlling energy metabolism in E. faecalis.
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Bøhle LA, Færgestad EM, Veiseth-Kent E, Steinmoen H, Nes IF, Eijsink VG, Mathiesen G. Identification of proteins related to the stress response in Enterococcus faecalis V583 caused by bovine bile. Proteome Sci 2010; 8:37. [PMID: 20579342 PMCID: PMC2907315 DOI: 10.1186/1477-5956-8-37] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 06/25/2010] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Enterococcus faecalis is an opportunistic pathogen and one of the most important causes of hospital infections. Bile acids are a major stress factor bacteria have to cope with in order to colonize and survive in the gastro-intestinal tract. The aim of this study was to investigate the effects of bile acids on the intracellular proteome of E. faecalis V583. RESULTS The proteomes of cells challenged with 1% bile were analyzed after 20 - 120 minutes exposure, using 2D gel electrophoresis and mass spectrometry. Among the approximately 500 observed proteins, 53 unique proteins were found to be regulated in response to bile and were identified with mass spectrometry. The identified proteins belonged to nine different functional classes, including fatty acid- and phospholipid-biosynthesis, energy metabolism, and transport and binding. Proteins involved in fatty acid and phospholipid biosynthesis pathways were clearly overrepresented among the identified proteins and all were down-regulated upon exposure to bile. The proteome data correlated reasonably well with data from previous transcriptome experiments done under the same conditions, but several differences were observed. CONCLUSION The results provide an overview of potentially important proteins that E. faecalis V583 needs to regulate in order to survive and adapt to a bile-rich environment, among which are several proteins involved in fatty acid and phospholipid biosynthesis pathways. In addition, this study reveals several hypothetical proteins, which are both abundant and clearly regulated and thus stand out as targets for future studies on bile stress.
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Affiliation(s)
- Liv Anette Bøhle
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Chr, M, Falsensvei 1, N-1432 As, Norway.
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Letek M, Fiuza M, Ordóñez E, Villadangos AF, Flärdh K, Mateos LM, Gil JA. DivIVA uses an N-terminal conserved region and two coiled-coil domains to localize and sustain the polar growth inCorynebacterium glutamicum. FEMS Microbiol Lett 2009; 297:110-6. [DOI: 10.1111/j.1574-6968.2009.01679.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Wang SB, Cantlay S, Nordberg N, Letek M, Gil JA, Flärdh K. Domains involved in the in vivo function and oligomerization of apical growth determinant DivIVA in Streptomyces coelicolor. FEMS Microbiol Lett 2009; 297:101-9. [PMID: 19552710 DOI: 10.1111/j.1574-6968.2009.01678.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The coiled-coil protein DivIVA is a determinant of apical growth and hyphal branching in Streptomyces coelicolor. We have investigated the properties of this protein and the involvement of different domains in its essential function and subcellular targeting. In S. coelicolor cell extracts, DivIVA was present as large oligomeric complexes that were not strongly membrane associated. The purified protein could self-assemble into extensive protein filaments in vitro. Two large and conspicuous segments in the amino acid sequence of streptomycete DivIVAs not present in other homologs, an internal PQG-rich segment and a carboxy-terminal extension, are shown to be dispensable for the essential function in S. coelicolor. Instead, the highly conserved amino-terminal of 22 amino acids was required and affected establishment of new DivIVA foci and hyphal branches, and an essential coiled-coil domain affected oligomerization of the protein.
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Affiliation(s)
- Sheng-Bing Wang
- Department of Cell and Organism Biology, Lund University, Lund, Sweden
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Silvestroni A, Jewell KA, Lin WJ, Connelly JE, Ivancic MM, Tao WA, Rajagopal L. Identification of serine/threonine kinase substrates in the human pathogen group B streptococcus. J Proteome Res 2009; 8:2563-74. [PMID: 19309132 PMCID: PMC2863997 DOI: 10.1021/pr900069n] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
All living organisms respond to changes in their internal and external environment for their survival and existence. Signaling is primarily achieved through reversible phosphorylation of proteins in both prokaryotes and eukaryotes. A change in the phosphorylation state of a protein alters its function to enable the control of cellular responses. A number of serine/threonine kinases regulate the cellular responses of eukaryotes. Although common in eukaryotes, serine/threonine kinases have only recently been identified in prokaryotes. We have described that the human pathogen Group B Streptococcus (GBS, Streptococcus agalactiae) encodes a single membrane-associated, serine/threonine kinase (Stk1) that is important for virulence of this bacterium. In this study, we used a combination of phosphopeptide enrichment and mass spectrometry to enrich and identify serine (S) and threonine (T) phosphopeptides of GBS. A comparison of S/T phosphopeptides identified from the Stk1 expressing strains to the isogenic stk1 mutant indicates that 10 proteins are potential substrates of the GBS Stk1 enzyme. Some of these proteins are phosphorylated by Stk1 in vitro and a site-directed substitution of the phosphorylated threonine to an alanine abolished phosphorylation of an Stk1 substrate. Collectively, these studies provide a novel approach to identify serine/threonine kinase substrates for insight into their signaling in human pathogens like GBS.
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Affiliation(s)
| | | | | | | | | | | | - Lakshmi Rajagopal
- Corresponding author. Mailing address: Seattle Children’s Hospital Research Institute, 1900 Ninth Ave., Seattle, WA 98101-1304. Phone: (206) 884-7336. Fax: (206) 884-7311.
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Pavlendová N, Muchová K, Barák I. Chromosome segregation in Bacillus subtilis. Folia Microbiol (Praha) 2008; 52:563-72. [PMID: 18450217 DOI: 10.1007/bf02932184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacillus subtilis, a Gram-positive bacterium commonly found in soil, is an excellent model organism for the study of basic cell processes, such as cell division and cell differentiation, called sporulation. In B. subtilis the essential genetic information is carried on a single circular chromosome, the correct segregation of which is crucial for both vegetative growth and sporulation. The proper completion of life cycle requires each daughter cell to obtain identical genetic information. The consequences of inaccurate chromosome segregation can lead to formation of anucleate cells, cells with two chromosomes, or cells with incomplete chromosomes. Although bacteria miss the classical eukaryotic mitotic apparatus, the chromosome segregation is undeniably an active process tightly connected to other cell processes as DNA replication and compaction. To fully understand the chromosome segregation, it is necessary to study this process in a wider context and to examine the role of different proteins at various cell life cycle stages. The life cycle of B. subtilis is characteristic by its specific cell differentiation process where, two slightly different segregation mechanisms exist, specialized in vegetative growth and in sporulation.
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Affiliation(s)
- N Pavlendová
- Institute of Molecular Biology, Slovak Academy of Sciences, 845 51 Bratislava, Slovakia.
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Kang CM, Nyayapathy S, Lee JY, Suh JW, Husson RN. Wag31, a homologue of the cell division protein DivIVA, regulates growth, morphology and polar cell wall synthesis in mycobacteria. MICROBIOLOGY-SGM 2008; 154:725-735. [PMID: 18310019 DOI: 10.1099/mic.0.2007/014076-0] [Citation(s) in RCA: 198] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Mycobacterium tuberculosis genome contains 11 serine/threonine kinase genes, and the products of two of these, PknA and PknB, are key components of a signal transduction pathway that regulates cell division and/or morphology. Previously, we have shown that one substrate of these kinases is Wag31, a homologue of the cell division protein DivIVA that is present, but not known to be phosphorylated, in other Gram-positive bacteria. Here, we investigate the localization and function of Wag31 and its phosphorylation. We demonstrate that Wag31 is localized to the cell poles. We further show that wag31 is an essential gene and that depletion of its product causes a dramatic morphological change in which one end of the cell becomes round rather than rod-shaped. This abnormal morphology appears to be caused by a defect in polar peptidoglycan synthesis. Finally, expression of M. tuberculosis wag31 in the wag31 conditional mutant of Mycobacterium smegmatis altered the growth rate in a manner that depended on the phospho-acceptor residue encoded by the allele being expressed. Taken together, these results indicate that Wag31 regulates cell shape and cell wall synthesis in M. tuberculosis through a molecular mechanism by which the activity of Wag31 can be modulated in response to environmental signals.
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Affiliation(s)
- Choong-Min Kang
- Department of Biological Science, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
| | - Seeta Nyayapathy
- Department of Biological Science, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
| | - Jung-Yeon Lee
- Department of Biological Science, Myongji University, San 38-2, Namdong, Yongin, Republic of Korea
| | - Joo-Won Suh
- Department of Biological Science, Myongji University, San 38-2, Namdong, Yongin, Republic of Korea
| | - Robert N Husson
- Division of Infectious Diseases, Children's Hospital Boston, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
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Rigden MD, Baier C, Ramirez-Arcos S, Liao M, Wang M, Dillon JAR. Identification of the coiled-coil domains of Enterococcus faecalis DivIVA that mediate oligomerization and their importance for biological function. J Biochem 2008; 144:63-76. [PMID: 18388125 DOI: 10.1093/jb/mvn044] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bacillus subtilis (Bs) DivIVA comprises coiled-coil structures and self-associates forming a 10-12 mer complex in vitro. Using bioinformatic approaches, we determined that Enterococcus faecalis (Ef) DivIVA comprises four coiled-coil domains, one at the N-terminus, the second and the third in the central region of the protein and the fourth at the C-terminus. We determined that DivIVA(Ef) self-interacts and forms a 10-12 multimeric complex. Point mutations or deletions of the central regions predicted bioinformatically to disrupt the coiled-coil structures either eliminated or weakened DivIVA(Ef) self-interaction and reduced oligomerization. Mutations disrupting the N- and C-terminal coiled-coils of DivIVA(Ef) did not affect DivIVA(Ef) oligomerization. The introduction of DivIVA(Ef) mutations to both the N-terminal and the central coiled-coil domains were lethal unless rescued by expressing wild-type DivIVA(Ef) in trans. E. faecalis cells expressing these mutations displayed aberrant cell morphology, indicating disruption of the normal cell division phenotype. The results in E. faecalis also indicate that both the N-terminal and the central coiled-coil structures of DivIVA(Ef) are indispensable for proper biological function. Overexpression of wild-type DivIVA(Ef) in both rod-shaped and round Escherichia coli cells resulted in morphological changes, while the overexpression of DivIVA(Ef) mutations failed to induce such alterations.
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Affiliation(s)
- Marc D Rigden
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario K1H 8M5, Canada
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Greco C, Mastronardi C, Pagotto F, Mack D, Ramirez-Arcos S. Assessment of biofilm-forming ability of coagulase-negative staphylococci isolated from contaminated platelet preparations in Canada. Transfusion 2008; 48:969-77. [PMID: 18346023 DOI: 10.1111/j.1537-2995.2007.01631.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Coagulase-negative staphylococci (CoNS) are the most prevalent bacterial contaminants of platelet (PLT) preparations and have been implicated in adverse transfusion reactions worldwide. The most frequently identified contaminant is Staphylococcus epidermidis, which is noted for its ability to maintain chronic hospital-acquired infections by forming biofilms as a chief virulence mechanism. STUDY DESIGN AND METHODS Strains of S. epidermidis isolated from contaminated PLT preparations in Canada were distinguished via gene-specific polymerase chain reaction (PCR) with divIVA as a marker. Biofilm-forming ability was assessed by the presence of the gene icaD, slime production on Congo red agar, and biofilm formation on polystyrene surfaces. Production of polysaccharide intercellular adhesin (PIA) was resolved by immunofluorescence. RESULTS Eight of the 13 (62%) CoNS isolates under study were identified as S. epidermidis. Of these, four strains (50%) were classified as strong biofilm producers. Three of the four biofilm-positive strains (75%) produced slime, harbored the icaD gene, and had positive expression of PIA. CONCLUSIONS Despite the presumable commensal origin of the CoNS isolates, a large proportion of S. epidermidis strains demonstrated a potential for enhanced virulence. Identification of contaminant staphylococci as biofilm producers is thus relevant and informative with regard to treatment approach in the circumstance of inadvertent infection of a PLT recipient.
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Affiliation(s)
- Carey Greco
- Canadian Blood Services, Ottawa, Ontario, Canada
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Greco C, Mastronardi C, Pagotto F, Mack D, Ramirez-Arcos S. Assessment of biofilm-forming ability of coagulase-negative staphylococci isolated from contaminated platelet preparations in Canada. Transfusion 2008. [DOI: 10.1111/j.1537-2995.2007.01631.x-i2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Letek M, Fiuza M, Ordóñez E, Villadangos AF, Ramos A, Mateos LM, Gil JA. Cell growth and cell division in the rod-shaped actinomycete Corynebacterium glutamicum. Antonie van Leeuwenhoek 2008; 94:99-109. [PMID: 18283557 DOI: 10.1007/s10482-008-9224-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 01/29/2008] [Indexed: 10/22/2022]
Abstract
Bacterial cell growth and cell division are highly complicated and diversified biological processes. In most rod-shaped bacteria, actin-like MreB homologues produce helicoidal structures along the cell that support elongation of the lateral cell wall. An exception to this rule is peptidoglycan synthesis in the rod-shaped actinomycete Corynebacterium glutamicum, which is MreB-independent. Instead, during cell elongation this bacterium synthesizes new cell-wall material at the cell poles whereas the lateral wall remains inert. Thus, the strategy employed by C. glutamicum to acquire a rod-shaped morphology is completely different from that of Escherichia coli or Bacillus subtilis. Cell division in C. glutamicum also differs profoundly by the apparent absence in its genome of homologues of spatial or temporal regulators of cell division, and its cell division apparatus seems to be simpler than those of other bacteria. Here we review recent advances in our knowledge of the C. glutamicum cell cycle in order to further understand this very different model of rod-shape acquisition.
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Affiliation(s)
- Michal Letek
- Departamento de Biología Molecular. Area de Microbiología. Facultad de Biología, Universidad de León, Leon 24071, Spain
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Mastronardi CC, Ramírez-Arcos S. Quantitative PCR for detection and discrimination of the bloodborne pathogen Staphylococcus epidermidis in platelet preparations using divIVA and icaA as target genes. Can J Microbiol 2007; 53:1222-31. [DOI: 10.1139/w07-091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bacterial contamination of blood components is the major microbiological cause of transfusion-associated morbidity, with Staphylococcus epidermidis being the most frequently isolated organism from contaminated platelet preparations (PPs). We have recently shown that S. epidermidis forms biofilms during platelet storage, which might account for reported missed detection during routine screening. In this study, we developed a highly sensitive and specific multiplex quantitative PCR (QPCR) assay to detect S. epidermidis in PPs at levels of 102–103 cfu/mL. A specific primer pair and hydrolysis probe were designed to amplify an internal region of the cell division divIVA gene that is unique to S. epidermidis. In addition, an internal sequence of the virulence gene icaA, which is involved in the synthesis of the S. epidermidis biofilm matrix, was selected to allow for differentiation of potentially biofilm-forming S. epidermidis isolates. A conserved region of the 8 alleles of the HLA-DQα1 locus present in residual white blood cells in PPs was selected as an internal control for the assay. The specificity of this assay was confirmed, as other staphylococcal species that were tested with the optimized parameters were not detected. This QPCR assay could be adaptable for the detection of other bloodborne bacterial pathogens.
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Nguyen L, Scherr N, Gatfield J, Walburger A, Pieters J, Thompson CJ. Antigen 84, an effector of pleiomorphism in Mycobacterium smegmatis. J Bacteriol 2007; 189:7896-910. [PMID: 17766411 PMCID: PMC2168712 DOI: 10.1128/jb.00726-07] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
While in most rod-shaped bacteria, morphology is based on MreB-like proteins that form an actin-like cytoskeletal scaffold for cell wall biosynthesis, the factors that determine the more flexible rod-like shape in actinobacteria such as Mycobacterium species are unknown. Here we show that a Mycobacterium smegmatis protein homologous to eubacterial DivIVA-like proteins, including M. tuberculosis antigen 84 (Ag84), localized symmetrically to centers of peptidoglycan biosynthesis at the poles and septa. Controlled gene disruption experiments indicated that the gene encoding Ag84, wag31, was essential; when overexpressed, cells became longer and wider, with Ag84 asymmetrically distributed at one pole. Many became grossly enlarged, bowling-pin-shaped cells having up to 80-fold-increased volume. In these cells, Ag84 accumulated predominantly at a bulbous pole that was apparently generated by uncontrolled cell wall expansion. In some cells, Ag84 was associated with exceptional sites of cell wall expansion (buds) that evolved into branches. M. bovis BCG Ag84 was able to form oligomers in vitro, perhaps reflecting its superstructure in vivo. These data suggested a role for Ag84 in cell division and modulating cell shape in pleiomorphic actinobacteria.
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Affiliation(s)
- Liem Nguyen
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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Kim JH, Mills DA. Improvement of a nisin-inducible expression vector for use in lactic acid bacteria. Plasmid 2007; 58:275-83. [PMID: 17624430 DOI: 10.1016/j.plasmid.2007.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2007] [Revised: 04/28/2007] [Accepted: 05/12/2007] [Indexed: 11/20/2022]
Abstract
The plasmid pMSP3535 is a popular vector for nisin-inducible expression of heterologous genes in lactic acid bacteria. However, the maximum protein expression level achievable with pMSP3535 is relatively low. In an effort to increase expression we modified pMSP3535 to create a high expression variant termed pMSP3535H2. Modifications included removal of a small NisA peptide fragment from the P nisA promoter and addition of a bidirectional transcription terminator. In addition the plasmid copy number was increased by replacing the pMSP3535 copy number control region with that of a high copy variant of the same replicon. As a result of these modifications, expression of two target proteins, the green fluorescent protein and the Escherichia coli antigen intimin, increased 5.0- and 7.5-fold, respectively. The increased range of inducible expression achieved with pMSP3535H2 will facilitate molecular studies in a range of lactic acid bacteria.
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Affiliation(s)
- Jae-Han Kim
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
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Vicente M, García-Ovalle M. Making a point: the role of DivIVA in streptococcal polar anatomy. J Bacteriol 2006; 189:1185-8. [PMID: 17114258 PMCID: PMC1797335 DOI: 10.1128/jb.01710-06] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Miguel Vicente
- Centro Nacional de Biotecnología, CSIC Campus de Cantoblanco, 28049 Madrid, Spain.
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Fadda D, Santona A, D'Ulisse V, Ghelardini P, Ennas MG, Whalen MB, Massidda O. Streptococcus pneumoniae DivIVA: localization and interactions in a MinCD-free context. J Bacteriol 2006; 189:1288-98. [PMID: 17098892 PMCID: PMC1797354 DOI: 10.1128/jb.01168-06] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To clarify the function of DivIVA in Streptococcus pneumoniae, we localized this protein in exponentially growing cells by both immunofluorescence microscopy and immunoelectron microscopy and found that S. pneumoniae DivIVA (DivIVA(SPN)) had a unique localization profile: it was present simultaneously both as a ring at the division septum and as dots at the cell poles. Double-immunofluorescence analysis suggested that DivIVA is recruited to the septum at a later stage than FtsZ and is retained at the poles after cell separation. All the other cell division proteins that we tested were localized in the divIVA null mutant, although the percentage of cells having constricted Z rings was significantly reduced. In agreement with its localization profile and consistent with its coiled-coil nature, DivIVA interacted with itself and with a number of known or putative S. pneumoniae cell division proteins. Finally, a missense divIVA mutant, obtained by allelic replacement, allowed us to correlate, at the molecular level, the specific interactions and some of the facets of the divIVA mutant phenotype. Taken together, the results suggest that although the possibility of a direct role in chromosome segregation cannot be ruled out, DivIVA in S. pneumoniae seems to be primarily involved in the formation and maturation of the cell poles. The localization and the interaction properties of DivIVA(SPN) raise the intriguing possibility that a common, MinCD-independent function evolved differently in the various host backgrounds.
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Affiliation(s)
- Daniela Fadda
- Dipartimento di Scienze e Tecnologie Biomediche, Sez. Microbiologia Medica, Via Porcell, 4, 09100 Cagliari, Italy
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Perry SE, Edwards DH. The Bacillus subtilis DivIVA protein has a sporulation-specific proximity to Spo0J. J Bacteriol 2006; 188:6039-43. [PMID: 16885474 PMCID: PMC1540055 DOI: 10.1128/jb.01750-05] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bacillus subtilis DivIVA protein controls the positioning of the division site and the relocation of the chromosome during sporulation. By performing coimmunoprecipitation experiments, we demonstrated that a myc-DivIVA protein is in proximity to FtsZ and MinD during vegetative growth and Spo0J during the first 120 min of sporulation.
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Affiliation(s)
- S E Perry
- Division of Pathology and Neuroscience, University of Dundee, Ninewells Medical School, Dundee, DD19SY, United Kingdom
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Nallapareddy SR, Singh KV, Murray BE. Construction of improved temperature-sensitive and mobilizable vectors and their use for constructing mutations in the adhesin-encoding acm gene of poorly transformable clinical Enterococcus faecium strains. Appl Environ Microbiol 2006; 72:334-45. [PMID: 16391062 PMCID: PMC1352270 DOI: 10.1128/aem.72.1.334-345.2006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inactivation by allelic exchange in clinical isolates of the emerging nosocomial pathogen Enterococcus faecium has been hindered by lack of efficient tools, and, in this study, transformation of clinical isolates was found to be particularly problematic. For this reason, a vector for allelic replacement (pTEX5500ts) was constructed that includes (i) the pWV01-based gram-positive repAts replication region, which is known to confer a high degree of temperature intolerance, (ii) Escherichia coli oriR from pUC18, (iii) two extended multiple-cloning sites located upstream and downstream of one of the marker genes for efficient cloning of flanking regions for double-crossover mutagenesis, (iv) transcriptional terminator sites to terminate undesired readthrough, and (v) a synthetic extended promoter region containing the cat gene for allelic exchange and a high-level gentamicin resistance gene, aph(2'')-Id, to distinguish double-crossover recombination, both of which are functional in gram-positive and gram-negative backgrounds. To demonstrate the functionality of this vector, the vector was used to construct an acm (encoding an adhesin to collagen from E. faecium) deletion mutant of a poorly transformable multidrug-resistant E. faecium endocarditis isolate, TX0082. The acm-deleted strain, TX6051 (TX0082Deltaacm), was shown to lack Acm on its surface, which resulted in the abolishment of the collagen adherence phenotype observed in TX0082. A mobilizable derivative (pTEX5501ts) that contains oriT of Tn916 to facilitate conjugative transfer from the transformable E. faecalis strain JH2Sm::Tn916 to E. faecium was also constructed. Using this vector, the acm gene of a nonelectroporable E. faecium wound isolate was successfully interrupted. Thus, pTEX5500ts and its mobilizable derivative demonstrated their roles as important tools by helping to create the first reported allelic replacement in E. faecium; the constructed this acm deletion mutant will be useful for assessing the role of acm in E. faecium pathogenesis using animal models.
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Affiliation(s)
- Sreedhar R Nallapareddy
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School at Houston, 6431 Fannin St., MSB 2.112, Houston, TX 77030, USA
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