1
|
Kandari D, Joshi H. PerR: A Peroxide Sensor Eliciting Metal Ion-dependent Regulation in Various Bacteria. Mol Biotechnol 2024:10.1007/s12033-024-01266-8. [PMID: 39294512 DOI: 10.1007/s12033-024-01266-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Accepted: 08/20/2024] [Indexed: 09/20/2024]
Abstract
Bacteria have to thrive in difficult conditions wherein their competitors generate partially reduced forms of oxygen, like hydrogen peroxide and superoxides. These oxidative stress molecules can also arise from within via the autoxidation of redox enzymes. To adapt to such conditions, bacteria express detox enzymes as well as repair proteins. Transcription factors regulate these defenses, and PerR is one of them. PerR is a Fur family transcriptional regulator that senses peroxide stress. Metal-bound PerR (either Mn2+ or Fe2+) can repress transcription of its regulon, but only the Fe2+-bound form of PerR can sense H2O2. This review describes different aspects of PerR and its varied roles, specifically in bacterial pathogens. Despite having roles beyond sensing peroxides, it is an underrated regulator that needs to be explored more deeply in pathogens.
Collapse
Affiliation(s)
- Divya Kandari
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Hemant Joshi
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
- Division of Experimental Medicine, University of California, San Francisco, CA, 94107, USA.
| |
Collapse
|
2
|
Jiang Q, Hu R, Liu F, Huang F, Zhang L, Zhang H. Characterization of a Novel Oxidative Stress Responsive Transcription Regulator in Mycobacterium bovis. Biomedicines 2024; 12:1872. [PMID: 39200336 PMCID: PMC11351531 DOI: 10.3390/biomedicines12081872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2024] [Accepted: 08/14/2024] [Indexed: 09/02/2024] Open
Abstract
The antioxidant defense is critical for the survival of intracellular pathogens such as Mycobacterium tuberculosis complex (MTBC) species, including Mycobacterium bovis, which are often exposed to an oxidative environment caused by reactive oxygen species (ROS) in hosts. However, the signaling pathway in mycobacteria for sensing and responding to oxidative stress remains largely unclear. In this study, we characterize a TetR-type transcription regulator BCG_3893c, designated AotM, as a novel redox sensor in Mycobacterium bovis that increases mycobacterial tolerance to oxidative stress. AotM is required for the growth of M. bovis in the presence of 1 mM hydrogen peroxide. Loss of the aotM gene leads to altered transcriptional profiles with 352 genes significantly up-regulated and 25 genes significantly down-regulated. AotM recognizes a 14-bp palindrome sequence motif and negatively regulates the expression of a FAD-dependent oxidoreductase encoded by bcg_3892c. Overexpression of BCG_3892c increases intracellular ROS production and reduces the growth of M. bovis. In summary, we propose that AotM enhances the mycobacterial resistance against oxidative stress probably by inhibiting intracellular ROS production. Our findings reveal a novel underlying regulatory mechanism behind mycobacterial oxidative stress adaptation.
Collapse
Affiliation(s)
- Qiang Jiang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Q.J.)
| | - Rong Hu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Q.J.)
| | - Feng Liu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Q.J.)
| | - Feng Huang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Q.J.)
| | - Lei Zhang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Hua Zhang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; (Q.J.)
| |
Collapse
|
3
|
Savin A, Anderson EE, Dyzenhaus S, Podkowik M, Shopsin B, Pironti A, Torres VJ. Staphylococcus aureus senses human neutrophils via PerR to coordinate the expression of the toxin LukAB. Infect Immun 2024; 92:e0052623. [PMID: 38235972 PMCID: PMC10863418 DOI: 10.1128/iai.00526-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/19/2024] Open
Abstract
Staphylococcus aureus is a gram-positive pathogen that poses a major health concern, in part due to its large array of virulence factors that allow infection and evasion of the immune system. One of these virulence factors is the bicomponent pore-forming leukocidin LukAB. The regulation of lukAB expression is not completely understood, especially in the presence of immune cells such as human polymorphonuclear neutrophils (hPMNs). Here, we screened for transcriptional regulators of lukAB during the infection of primary hPMNs. We uncovered that PerR, a peroxide sensor, is vital for hPMN-mediated induction of lukAB and that PerR upregulates cytotoxicity during the infection of hPMNs. Exposure of S. aureus to hydrogen peroxide (H2O2) alone also results in increased lukAB promoter activity, a phenotype dependent on PerR. Collectively, our data suggest that S. aureus uses PerR to sense the H2O2 produced by hPMNs to stimulate the expression of lukAB, allowing the bacteria to withstand these critical innate immune cells.IMPORTANCEStaphylococcus aureus utilizes a diverse set of virulence factors, such as leukocidins, to subvert human neutrophils, but how these toxins are regulated is incompletely defined. Here, we identified the peroxide-sensitive repressor, PerR, as a required protein involved in the induction of lukAB in the presence of primary human neutrophils, a phenotype directly linked to the ability of PerR to sense H2O2. Thus, we show that S. aureus coordinates sensing and resistance to oxidative stress with toxin production to promote pathogen survival.
Collapse
Affiliation(s)
- Avital Savin
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biology, New York University, New York, New York, USA
| | - Exene E. Anderson
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sophie Dyzenhaus
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Magdalena Podkowik
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
- Division of Infectious Diseases, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
- Division of Infectious Diseases, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Department of Host-Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| |
Collapse
|
4
|
Abstract
Oxidative stress is an important and pervasive physical stress encountered by all kingdoms of life, including bacteria. In this review, we briefly describe the nature of oxidative stress, highlight well-characterized protein-based sensors (transcription factors) of reactive oxygen species that serve as standards for molecular sensors in oxidative stress, and describe molecular studies that have explored the potential of direct RNA sensitivity to oxidative stress. Finally, we describe the gaps in knowledge of RNA sensors-particularly regarding the chemical modification of RNA nucleobases. RNA sensors are poised to emerge as an essential layer of understanding and regulating dynamic biological pathways in oxidative stress responses in bacteria and, thus, also represent an important frontier of synthetic biology.
Collapse
Affiliation(s)
- Ryan Buchser
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Phillip Sweet
- Integrative Life Sciences Program, University of Texas at Austin, Austin, Texas, USA
| | - Aparna Anantharaman
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Lydia Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
- Integrative Life Sciences Program, University of Texas at Austin, Austin, Texas, USA
| |
Collapse
|
5
|
Sun H, Si F, Zhao X, Li F, Qi G. The cellular redox state in Bacillus amyloliquefaciens WH1 affects biofilm formation indirectly in a surfactant direct manner. J Basic Microbiol 2023. [PMID: 37189223 DOI: 10.1002/jobm.202300064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/30/2023] [Accepted: 04/27/2023] [Indexed: 05/17/2023]
Abstract
Surfactin is a signal to trigger biofilm formation against harsh environments. Generally, harsh environments can result in change of the cellular redox state to induce biofilm formation, but we know little about whether the cellular redox state influences biofilm formation via surfactin. Here, the reductant glucose could reduce surfactin and enhance biofilm formation by a surfactin-indirect way. The oxidant H2 O2 led to a decrease of surfactin accompanying with weakened biofilm formation. Spx and PerR were both necessary for surfactin production and biofilm formation. H2 O2 improved surfactin production but inhibited biofilm formation by a surfactin-indirect manner in Δspx, while it reduced surfactin production without obvious influence on biofilm formation in ΔperR. The ability against H2 O2 stress was enhanced in Δspx, but weakened in ΔperR. Thereby, PerR was favorable for resisting oxidative stress, while Spx played a negative role in this action. Knockout and compensation of rex also supported that the cells could form biofilm by a surfactin-indirect way. Collectively, surfactin is not a unique signal to trigger biofilm formation, and the cellular redox state can influence biofilm formation by a surfactin-direct or -indirect way in Bacillus amyloliquefaciens WH1.
Collapse
Affiliation(s)
- Huiwan Sun
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fengmei Si
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xiuyun Zhao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Feng Li
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Gaofu Qi
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| |
Collapse
|
6
|
Meireles DA, da Silva Neto JF, Domingos RM, Alegria TGP, Santos LCM, Netto LES. Ohr - OhrR, a neglected and highly efficient antioxidant system: Structure, catalysis, phylogeny, regulation, and physiological roles. Free Radic Biol Med 2022; 185:6-24. [PMID: 35452809 DOI: 10.1016/j.freeradbiomed.2022.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/09/2022] [Accepted: 04/02/2022] [Indexed: 12/24/2022]
Abstract
Ohrs (organic hydroperoxide resistance proteins) are antioxidant enzymes that play central roles in the response of microorganisms to organic peroxides. Here, we describe recent advances in the structure, catalysis, phylogeny, regulation, and physiological roles of Ohr proteins and of its transcriptional regulator, OhrR, highlighting their unique features. Ohr is extremely efficient in reducing fatty acid peroxides and peroxynitrite, two oxidants relevant in host-pathogen interactions. The highly reactive Cys residue of Ohr, named peroxidatic Cys (Cp), composes together with an arginine and a glutamate the catalytic triad. The catalytic cycle of Ohrs involves a condensation between a sulfenic acid (Cp-SOH) and the thiol of the second conserved Cys, leading to the formation of an intra-subunit disulfide bond, which is then reduced by dihydrolipoamide or lipoylated proteins. A structural switch takes place during catalysis, with the opening and closure of the active site by the so-called Arg-loop. Ohr is part of the Ohr/OsmC super-family that also comprises OsmC and Ohr-like proteins. Members of the Ohr, OsmC and Ohr-like subgroups present low sequence similarities among themselves, but share a high structural conservation, presenting two Cys residues in their active site. The pattern of gene expression is also distinct among members of the Ohr/OsmC subfamilies. The expression of ohr genes increases upon organic hydroperoxides treatment, whereas the signals for the upregulation of osmC are entry into the stationary phase and/or osmotic stress. For many ohr genes, the upregulation by organic hydroperoxides is mediated by OhrR, a Cys-based transcriptional regulator that only binds to its target DNAs in its reduced state. Since Ohrs and OhrRs are involved in virulence of some microorganisms and are absent in vertebrate and vascular plants, they may represent targets for novel therapeutic approaches based on the disruption of this key bacterial organic peroxide defense system.
Collapse
Affiliation(s)
- Diogo A Meireles
- Laboratório de Fisiologia e Bioquímica de Microrganismos (LFBM) da Universidade Estadual do Norte Fluminense Darcy Ribeiro, Brazil
| | - José F da Silva Neto
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (FMRP-USP), Brazil
| | | | - Thiago G P Alegria
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Lene Clara M Santos
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Luis Eduardo S Netto
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, Brazil.
| |
Collapse
|
7
|
Redirected Stress Responses in a Genome-Minimized 'midi Bacillus' Strain with Enhanced Capacity for Protein Secretion. mSystems 2021; 6:e0065521. [PMID: 34904864 PMCID: PMC8670375 DOI: 10.1128/msystems.00655-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Genome engineering offers the possibility to create completely novel cell factories with enhanced properties for biotechnological applications. In recent years, genome minimization was extensively explored in the Gram-positive bacterial cell factory Bacillus subtilis, where up to 42% of the genome encoding dispensable functions was removed. Such studies showed that some strains with minimized genomes gained beneficial features, especially for secretory protein production. However, strains with the most minimal genomes displayed growth defects. This focused our attention on strains with less extensive genomic deletions that display close-to-wild-type growth properties while retaining the acquired beneficial traits in secretory protein production. A strain of this category is B. subtilis IIG-Bs27-47-24, here referred to as midiBacillus, which lacks 30.95% of the parental genome. To date, it was unknown how the altered genomic configuration of midiBacillus impacts cell physiology in general, and protein secretion in particular. The present study bridges this knowledge gap through comparative quantitative proteome analyses with focus on protein secretion. Interestingly, the results show that the secretion stress responses of midiBacillus, as elicited by high-level expression of the immunodominant staphylococcal antigen A, are completely different from secretion stress responses that occur in the parental strain 168. We further show that midiBacillus has an increased capacity for translation and that a variety of critical Sec secretion machinery components is present at elevated levels. Altogether, our observations demonstrate that high-level protein secretion has different consequences for wild-type and genome-engineered Bacillus strains, dictated by the altered genomic and proteomic configurations. IMPORTANCE Our present study showcases a genome-minimized nonpathogenic bacterium, the so-called midiBacillus, as a chassis for the development of future industrial strains that serve in the production of high-value difficult-to-produce proteins. In particular, we explain how midiBacillus, which lacks about one-third of the original genome, effectively secretes a protein of the major human pathogen Staphylococcus aureus that cannot be produced by the parental Bacillus subtilis strain. This is important, because the secreted S. aureus protein is exemplary for a range of targets that can be implemented in future antistaphylococcal immunotherapies. Accordingly, we anticipate that midiBacillus chassis will contribute to the development of vaccines that protect both humans and livestock against diseases caused by S. aureus, a bacterial pathogen that is increasingly difficult to fight with antibiotics, because it has accumulated resistances to essentially all antibiotics that are currently in clinical practice.
Collapse
|
8
|
Microbial Lipopeptide-Producing Strains and Their Metabolic Roles under Anaerobic Conditions. Microorganisms 2021; 9:microorganisms9102030. [PMID: 34683351 PMCID: PMC8540375 DOI: 10.3390/microorganisms9102030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 01/17/2023] Open
Abstract
The lipopeptide produced by microorganisms is one of the representative biosurfactants and is characterized as a series of structural analogues of different families. Thirty-four families covering about 300 lipopeptide compounds have been reported in the last decades, and most of the reported lipopeptides produced by microorganisms were under aerobic conditions. The lipopeptide-producing strains under anaerobic conditions have attracted much attention from both the academic and industrial communities, due to the needs and the challenge of their applications in anaerobic environments, such as in oil reservoirs and in microbial enhanced oil recovery (MEOR). In this review, the fifty-eight reported bacterial strains, mostly isolated from oil reservoirs and dominated by the species Bacillus subtilis, producing lipopeptide biosurfactants, and the species Pseudomonas aeruginosa, producing glycolipid biosurfactants under anaerobic conditions were summarized. The metabolic pathway and the non-ribosomal peptide synthetases (NRPSs) of the strain Bacillus subtilis under anaerobic conditions were analyzed, which is expected to better understand the key mechanisms of the growth and production of lipopeptide biosurfactants of such kind of bacteria under anaerobic conditions, and to expand the industrial application of anaerobic biosurfactant-producing bacteria.
Collapse
|
9
|
Fassler R, Zuily L, Lahrach N, Ilbert M, Reichmann D. The Central Role of Redox-Regulated Switch Proteins in Bacteria. Front Mol Biosci 2021; 8:706039. [PMID: 34277710 PMCID: PMC8282892 DOI: 10.3389/fmolb.2021.706039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/18/2021] [Indexed: 01/11/2023] Open
Abstract
Bacteria possess the ability to adapt to changing environments. To enable this, cells use reversible post-translational modifications on key proteins to modulate their behavior, metabolism, defense mechanisms and adaptation of bacteria to stress. In this review, we focus on bacterial protein switches that are activated during exposure to oxidative stress. Such protein switches are triggered by either exogenous reactive oxygen species (ROS) or endogenous ROS generated as by-products of the aerobic lifestyle. Both thiol switches and metal centers have been shown to be the primary targets of ROS. Cells take advantage of such reactivity to use these reactive sites as redox sensors to detect and combat oxidative stress conditions. This in turn may induce expression of genes involved in antioxidant strategies and thus protect the proteome against stress conditions. We further describe the well-characterized mechanism of selected proteins that are regulated by redox switches. We highlight the diversity of mechanisms and functions (as well as common features) across different switches, while also presenting integrative methodologies used in discovering new members of this family. Finally, we point to future challenges in this field, both in uncovering new types of switches, as well as defining novel additional functions.
Collapse
Affiliation(s)
- Rosi Fassler
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lisa Zuily
- Aix-Marseille University, CNRS, BIP, UMR 7281, IMM, Marseille, France
| | - Nora Lahrach
- Aix-Marseille University, CNRS, BIP, UMR 7281, IMM, Marseille, France
| | - Marianne Ilbert
- Aix-Marseille University, CNRS, BIP, UMR 7281, IMM, Marseille, France
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
10
|
Linzner N, Loi VV, Fritsch VN, Antelmann H. Thiol-based redox switches in the major pathogen Staphylococcus aureus. Biol Chem 2020; 402:333-361. [PMID: 33544504 DOI: 10.1515/hsz-2020-0272] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/05/2020] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus is a major human pathogen, which encounters reactive oxygen, nitrogen, chlorine, electrophile and sulfur species (ROS, RNS, RCS, RES and RSS) by the host immune system, during cellular metabolism or antibiotics treatments. To defend against redox active species and antibiotics, S. aureus is equipped with redox sensing regulators that often use thiol switches to control the expression of specific detoxification pathways. In addition, the maintenance of the redox balance is crucial for survival of S. aureus under redox stress during infections, which is accomplished by the low molecular weight (LMW) thiol bacillithiol (BSH) and the associated bacilliredoxin (Brx)/BSH/bacillithiol disulfide reductase (YpdA)/NADPH pathway. Here, we present an overview of thiol-based redox sensors, its associated enzymatic detoxification systems and BSH-related regulatory mechanisms in S. aureus, which are important for the defense under redox stress conditions. Application of the novel Brx-roGFP2 biosensor provides new insights on the impact of these systems on the BSH redox potential. These thiol switches of S. aureus function in protection against redox active desinfectants and antimicrobials, including HOCl, the AGXX® antimicrobial surface coating, allicin from garlic and the naphthoquinone lapachol. Thus, thiol switches could be novel drug targets for the development of alternative redox-based therapies to combat multi-drug resistant S. aureus isolates.
Collapse
Affiliation(s)
- Nico Linzner
- Freie Universität Berlin, Institute of Biology-Microbiology, Königin-Luise-Straße 12-16, D-14195Berlin, Germany
| | - Vu Van Loi
- Freie Universität Berlin, Institute of Biology-Microbiology, Königin-Luise-Straße 12-16, D-14195Berlin, Germany
| | - Verena Nadin Fritsch
- Freie Universität Berlin, Institute of Biology-Microbiology, Königin-Luise-Straße 12-16, D-14195Berlin, Germany
| | - Haike Antelmann
- Freie Universität Berlin, Institute of Biology-Microbiology, Königin-Luise-Straße 12-16, D-14195Berlin, Germany
| |
Collapse
|
11
|
Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci. Microbiol Mol Biol Rev 2019; 83:83/3/e00008-19. [PMID: 31315902 DOI: 10.1128/mmbr.00008-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
Collapse
|
12
|
Abstract
SIGNIFICANCE Iron is required for growth and is often redox active under cytosolic conditions. As a result of its facile redox chemistry, iron homeostasis is intricately involved with oxidative stress. Bacterial adaptation to iron limitation and oxidative stress often involves ferric uptake regulator (Fur) proteins: a diverse set of divalent cation-dependent, DNA-binding proteins that vary widely in both metal selectivity and sensitivity to metal-catalyzed oxidation. Recent Advances: Bacteria contain two Fur family metalloregulators that use ferrous iron (Fe2+) as their cofactor, Fur and PerR. Fur functions to regulate iron homeostasis in response to changes in intracellular levels of Fe2+. PerR also binds Fe2+, which enables metal-catalyzed protein oxidation as a mechanism for sensing hydrogen peroxide (H2O2). CRITICAL ISSUES To effectively regulate iron homeostasis, Fur has an Fe2+ affinity tuned to monitor the labile iron pool of the cell and may be under selective pressure to minimize iron oxidation, which would otherwise lead to an inappropriate increase in iron uptake under oxidative stress conditions. Conversely, Fe2+ is bound more tightly to PerR but exhibits high H2O2 reactivity, which enables a rapid induction of peroxide stress genes. FUTURE DIRECTIONS The features that determine the disparate reactivity of these proteins with oxidants are still poorly understood. A controlled, comparative analysis of the affinities of Fur/PerR proteins for their metal cofactors and their rate of reactivity with H2O2, combined with structure/function analyses, will be needed to define the molecular mechanisms that have facilitated this divergence of function between these two paralogous regulators.
Collapse
Affiliation(s)
| | - John D Helmann
- Department of Microbiology, Cornell University , Ithaca, New York
| |
Collapse
|
13
|
Sarvan S, Butcher J, Stintzi A, Couture JF. Variation on a theme: investigating the structural repertoires used by ferric uptake regulators to control gene expression. Biometals 2018; 31:681-704. [DOI: 10.1007/s10534-018-0120-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 06/12/2018] [Indexed: 11/29/2022]
|
14
|
Anti-σ factor YlaD regulates transcriptional activity of σ factor YlaC and sporulation via manganese-dependent redox-sensing molecular switch in Bacillus subtilis. Biochem J 2018; 475:2127-2151. [PMID: 29760236 DOI: 10.1042/bcj20170911] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 04/29/2018] [Accepted: 05/14/2018] [Indexed: 02/01/2023]
Abstract
YlaD, a membrane-anchored anti-sigma (σ) factor of Bacillus subtilis, contains a HX3CXXC motif that functions as a redox-sensing domain and belongs to one of the zinc (Zn)-co-ordinated anti-σ factor families. Despite previously showing that the YlaC transcription is controlled by YlaD, experimental evidence of how the YlaC-YlaD interaction is affected by active cysteines and/or metal ions is lacking. Here, we showed that the P yla promoter is autoregulated solely by YlaC. Moreover, reduced YlaD contained Zn and iron, while oxidized YlaD did not. Cysteine substitution in YlaD led to changes in its secondary structure; Cys3 had important structural functions in YlaD, and its mutation caused dissociation from YlaC, indicating the essential requirement of a HX3CXXC motif for regulating interactions of YlaC with YlaD. Analyses of the far-UV CD spectrum and metal content revealed that the addition of Mn ions to Zn-YlaD changed its secondary structure and that iron was substituted for manganese (Mn). The ylaC gene expression using βGlu activity from P yla :gusA was observed at the late-exponential and early-stationary phase, and the ylaC-overexpressing mutant constitutively expressed gene transcripts of clpP and sigH, an important alternative σ factor regulated by ClpXP. Collectively, our data demonstrated that YlaD senses redox changes and elicits increase in Mn ion concentrations and that, in turn, YlaD-mediated transcriptional activity of YlaC regulates sporulation initiation under oxidative stress and Mn-substituted conditions by regulating clpP gene transcripts. This is the first report of the involvement of oxidative stress-responsive B. subtilis extracytoplasmic function σ factors during sporulation via a Mn-dependent redox-sensing molecular switch.
Collapse
|
15
|
Liu G, Liu X, Xu H, Liu X, Zhou H, Huang Z, Gan J, Chen H, Lan L, Yang CG. Structural Insights into the Redox-Sensing Mechanism of MarR-Type Regulator AbfR. J Am Chem Soc 2017; 139:1598-1608. [PMID: 28086264 DOI: 10.1021/jacs.6b11438] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
As a master redox-sensing MarR-family transcriptional regulator, AbfR participates in oxidative stress responses and virulence regulations in Staphylococcus epidermidis. Here, we present structural insights into the DNA-binding mechanism of AbfR in different oxidation states by determining the X-ray crystal structures of a reduced-AbfR/DNA complex, an overoxidized (Cys13-SO2H and Cys13-SO3H) AbfR/DNA, and 2-disulfide cross-linked AbfR dimer. Together with biochemical analyses, our results suggest that the redox regulation of AbfR-sensing displays two novel features: (i) the reversible disulfide modification, but not the irreversible overoxidation, significantly abolishes the DNA-binding ability of the AbfR repressor; (ii) either 1-disulfide cross-linked or 2-disulfide cross-linked AbfR dimer is biologically significant. The overoxidized species of AbfR, resembling the reduced AbfR in conformation and retaining the DNA-binding ability, does not exist in biologically significant concentrations, however. The 1-disulfide cross-linked modification endows AbfR with significantly weakened capability for DNA-binding. The 2-disulfide cross-linked AbfR adopts a very "open" conformation that is incompatible with DNA-binding. Overall, the concise oxidation chemistry of the redox-active cysteine allows AbfR to sense and respond to oxidative stress correctly and efficiently.
Collapse
Affiliation(s)
- Guijie Liu
- Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China.,University of Chinese Academy of Sciences , Beijing 100049, China
| | - Xing Liu
- Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China.,CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China
| | - Hongjiao Xu
- Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China.,University of Chinese Academy of Sciences , Beijing 100049, China
| | - Xichun Liu
- Coordination Chemistry Institute and State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China
| | - Hu Zhou
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China
| | - Zhen Huang
- Department of Chemistry, Georgia State University , Atlanta, Georgia 30303, United States
| | - Jianhua Gan
- School of Life Sciences, Fudan University , Shanghai 200433, China
| | - Hao Chen
- Coordination Chemistry Institute and State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, China
| | - Lefu Lan
- Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China
| | - Cai-Guang Yang
- Laboratory of Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China
| |
Collapse
|
16
|
Sethu R, Gouré E, Signor L, Caux-Thang C, Clémancey M, Duarte V, Latour JM. Reaction of PerR with Molecular Oxygen May Assist H2O2 Sensing in Anaerobes. ACS Chem Biol 2016; 11:1438-44. [PMID: 26963368 DOI: 10.1021/acschembio.5b01054] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PerR is the peroxide resistance regulator found in several pathogenic bacteria and governs their resistance to peroxide stress by inducing enzymes that destroy peroxides. However, it has recently been implicated as a key component of the aerotolerance in several facultative or strict anaerobes, including the highly pathogenic Staphylococcus aureus. By combining (18)O labeling studies to ESI- and MALDI-TOF MS detection and EMSA experiments, we demonstrate that the active form of PerR reacts with dioxygen, which leads ultimately to disruption of the PerR/DNA complex and is thus physiologically meaningful. Moreover, we show that the presence of O2 assists PerR sensing of H2O2, another feature likely to be important for anaerobic organisms. These results allow one to envisage different scenarios for the response of anaerobes to air exposure.
Collapse
Affiliation(s)
- Ramakrishnan Sethu
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
- CEA, DSV, BIG, LCBM, PMB, F-38054 Grenoble, France
- CNRS UMR 5249, LCBM, F-38054 Grenoble, France
| | - Eric Gouré
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
- CEA, DSV, BIG, LCBM, PMB, F-38054 Grenoble, France
- CNRS UMR 5249, LCBM, F-38054 Grenoble, France
| | - Luca Signor
- Université Grenoble Alpes, IBS, F-38044 Grenoble, France
- CNRS, IBS, F-38044 Grenoble, France
- CEA, IBS, F-38044 Grenoble, France
| | - Christelle Caux-Thang
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
- CEA, DSV, BIG, LCBM, PMB, F-38054 Grenoble, France
- CNRS UMR 5249, LCBM, F-38054 Grenoble, France
| | - Martin Clémancey
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
- CEA, DSV, BIG, LCBM, PMB, F-38054 Grenoble, France
- CNRS UMR 5249, LCBM, F-38054 Grenoble, France
| | - Victor Duarte
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
- CEA, DSV, BIG, LCBM, PMB, F-38054 Grenoble, France
- CNRS UMR 5249, LCBM, F-38054 Grenoble, France
| | - Jean-Marc Latour
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
- CEA, DSV, BIG, LCBM, PMB, F-38054 Grenoble, France
- CNRS UMR 5249, LCBM, F-38054 Grenoble, France
| |
Collapse
|
17
|
Hillion M, Antelmann H. Thiol-based redox switches in prokaryotes. Biol Chem 2016; 396:415-44. [PMID: 25720121 DOI: 10.1515/hsz-2015-0102] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/05/2015] [Indexed: 12/12/2022]
Abstract
Bacteria encounter reactive oxygen species (ROS) as a consequence of the aerobic life or as an oxidative burst of activated neutrophils during infections. In addition, bacteria are exposed to other redox-active compounds, including hypochloric acid (HOCl) and reactive electrophilic species (RES) such as quinones and aldehydes. These reactive species often target the thiol groups of cysteines in proteins and lead to thiol-disulfide switches in redox-sensing regulators to activate specific detoxification pathways and to restore the redox balance. Here, we review bacterial thiol-based redox sensors that specifically sense ROS, RES and HOCl via thiol-based mechanisms and regulate gene transcription in Gram-positive model bacteria and in human pathogens, such as Staphylococcus aureus and Mycobacterium tuberculosis. We also pay particular attention to emerging widely conserved HOCl-specific redox regulators that have been recently characterized in Escherichia coli. Different mechanisms are used to sense and respond to ROS, RES and HOCl by 1-Cys-type and 2-Cys-type thiol-based redox sensors that include versatile thiol-disulfide switches (OxyR, OhrR, HypR, YodB, NemR, RclR, Spx, RsrA/RshA) or alternative Cys phosphorylations (SarZ, MgrA, SarA), thiol-S-alkylation (QsrR), His-oxidation (PerR) and methionine oxidation (HypT). In pathogenic bacteria, these redox-sensing regulators are often important virulence regulators and required for adapation to the host immune defense.
Collapse
|
18
|
Guan G, Pinochet-Barros A, Gaballa A, Patel SJ, Argüello JM, Helmann JD. PfeT, a P1B4 -type ATPase, effluxes ferrous iron and protects Bacillus subtilis against iron intoxication. Mol Microbiol 2015; 98:787-803. [PMID: 26261021 DOI: 10.1111/mmi.13158] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2015] [Indexed: 11/30/2022]
Abstract
Iron is an essential element for nearly all cells and limited iron availability often restricts growth. However, excess iron can also be deleterious, particularly when cells expressing high affinity iron uptake systems transition to iron rich environments. Bacillus subtilis expresses numerous iron importers, but iron efflux has not been reported. Here, we describe the B. subtilis PfeT protein (formerly YkvW/ZosA) as a P1B4 -type ATPase in the PerR regulon that serves as an Fe(II) efflux pump and protects cells against iron intoxication. Iron and manganese homeostasis in B. subtilis are closely intertwined: a pfeT mutant is iron sensitive, and this sensitivity can be suppressed by low levels of Mn(II). Conversely, a pfeT mutant is more resistant to Mn(II) overload. In vitro, the PfeT ATPase is activated by both Fe(II) and Co(II), although only Fe(II) efflux is physiologically relevant in wild-type cells, and null mutants accumulate elevated levels of intracellular iron. Genetic studies indicate that PfeT together with the ferric uptake repressor (Fur) cooperate to prevent iron intoxication, with iron sequestration by the MrgA mini-ferritin playing a secondary role. Protection against iron toxicity may also be a key role for related P1B4 -type ATPases previously implicated in bacterial pathogenesis.
Collapse
Affiliation(s)
- Guohua Guan
- Department of Microbiology, Cornell University, Ithaca, NY, 14853, USA.,State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | | | - Ahmed Gaballa
- Department of Microbiology, Cornell University, Ithaca, NY, 14853, USA
| | - Sarju J Patel
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA, 01609, USA
| | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, 14853, USA
| |
Collapse
|
19
|
Caux-Thang C, Parent A, Sethu R, Maïga A, Blondin G, Latour JM, Duarte V. Single asparagine to arginine mutation allows PerR to switch from PerR box to fur box. ACS Chem Biol 2015; 10:682-6. [PMID: 25486128 DOI: 10.1021/cb500783g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fur family proteins, ubiquitous in prokaryotes, play a pivotal role in microbial survival and virulence in most pathogens. Metalloregulators, such as Fur and PerR, regulate the transcription of genes connected to iron homeostasis and response to oxidative stress, respectively. In Bacillus subtilis, Fur and PerR bind with high affinity to DNA sequences differing at only two nucleotides. In addition to these differences in the PerR and Fur boxes, we identify in this study a residue located on the DNA binding motif of the Fur protein that is critical to discrimination between the two close DNA sequences. Interestingly, when this residue is introduced into PerR, it lowers the affinity of PerR for its own DNA target but confers to the protein the ability to interact strongly with the Fur DNA binding sequence. The present data show how two closely related proteins have distinct biological properties just by changing a single residue.
Collapse
Affiliation(s)
| | - Aubérie Parent
- Université Grenoble Alpes, LCBM, F-38054 Grenoble, France
| | | | | | | | | | | |
Collapse
|
20
|
|
21
|
Helmann JD. Specificity of metal sensing: iron and manganese homeostasis in Bacillus subtilis. J Biol Chem 2014; 289:28112-20. [PMID: 25160631 DOI: 10.1074/jbc.r114.587071] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Metalloregulatory proteins allow cells to sense metal ions and appropriately adjust the expression of metal uptake, storage, and efflux pathways. Bacillus subtilis provides a model for the coordinate regulation of iron and manganese homeostasis that involves three key regulators: Fur senses iron sufficiency, MntR senses manganese sufficiency, and PerR senses the intracellular Fe/Mn ratio. Here, I review the structural and physiological bases of selective metal perception, the effects of non-cognate metals, and mechanisms that may serve to coordinate iron and manganese homeostasis.
Collapse
Affiliation(s)
- John D Helmann
- From the Department of Microbiology, Cornell University, Ithaca, New York 14853-8101
| |
Collapse
|
22
|
Ouyang Z, Zhou J, Brautigam CA, Deka R, Norgard MV. Identification of a core sequence for the binding of BosR to the rpoS promoter region in Borrelia burgdorferi. MICROBIOLOGY-SGM 2014; 160:851-862. [PMID: 24608174 DOI: 10.1099/mic.0.075655-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The alternative sigma factor RpoS in Borrelia burgdorferi plays a central role in modulating host adaptive responses when spirochaetes cycle between ticks and mammals. The transcriptional activation of σ(54)-dependent rpoS requires a Fur homologue designated BosR. Previously, BosR was shown to directly activate rpoS transcription by binding to the rpoS promoter. However, many other DNA binding features of BosR have remained obscure. In particular, the precise DNA sequence targeted by BosR has not yet been completely elucidated. The prediction of a putative Per box within the rpoS promoter region has further confounded the identification of the BosR binding sequence. Herein, by using electrophoretic mobility shift assays, we demonstrate that the putative Per box predicted in the rpoS promoter region is not involved in the binding of BosR. Rather, a 13 bp palindromic sequence (ATTTAANTTAAAT) with dyad symmetry, which we denote as the 'BosR box', functions as the core sequence recognized by BosR in the rpoS promoter region of Borrelia burgdorferi. Similar to a Fur box and a Per box, the BosR box probably comprises a 6-1-6 inverted repeat composed of two hexamers (ATTTAA) in a head-to-tail orientation. Selected mutations in the BosR box prevented recombinant BosR from binding to rpoS. In addition, we found that sequences neighbouring the BosR box also are required for the formation of BosR-DNA complexes. Identification of the BosR box advances our understanding of how BosR recognizes its DNA target(s), and provides new insight into the mechanistic details behind the unique regulatory function of BosR.
Collapse
Affiliation(s)
- Zhiming Ouyang
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jianli Zhou
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chad A Brautigam
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ranjit Deka
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael V Norgard
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
23
|
Lin CSH, Chao SY, Hammel M, Nix JC, Tseng HL, Tsou CC, Fei CH, Chiou HS, Jeng US, Lin YS, Chuang WJ, Wu JJ, Wang S. Distinct structural features of the peroxide response regulator from group A Streptococcus drive DNA binding. PLoS One 2014; 9:e89027. [PMID: 24586487 PMCID: PMC3931707 DOI: 10.1371/journal.pone.0089027] [Citation(s) in RCA: 13] [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: 07/15/2013] [Accepted: 01/19/2014] [Indexed: 11/23/2022] Open
Abstract
Group A streptococcus (GAS, Streptococcus pyogenes) is a strict human pathogen that causes severe, invasive diseases. GAS does not produce catalase, but has an ability to resist killing by reactive oxygen species (ROS) through novel mechanisms. The peroxide response regulator (PerR), a member of ferric uptake regulator (Fur) family, plays a key role for GAS to cope with oxidative stress by regulating the expression of multiple genes. Our previous studies have found that expression of an iron-binding protein, Dpr, is under the direct control of PerR. To elucidate the molecular interactions of PerR with its cognate promoter, we have carried out structural studies on PerR and PerR-DNA complex. By combining crystallography and small-angle X-ray scattering (SAXS), we confirmed that the determined PerR crystal structure reflects its conformation in solution. Through mutagenesis and biochemical analysis, we have identified DNA-binding residues suggesting that PerR binds to the dpr promoter at the per box through a winged-helix motif. Furthermore, we have performed SAXS analysis and resolved the molecular architecture of PerR-DNA complex, in which two 30 bp DNA fragments wrap around two PerR homodimers by interacting with the adjacent positively-charged winged-helix motifs. Overall, we provide structural insights into molecular recognition of DNA by PerR and define the hollow structural arrangement of PerR-30bpDNA complex, which displays a unique topology distinct from currently proposed DNA-binding models for Fur family regulators.
Collapse
Affiliation(s)
- Chang Sheng-Huei Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shi-Yu Chao
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Michal Hammel
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Jay C. Nix
- Molecular Biology Consortium, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Hsiao-Ling Tseng
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| | - Chih-Cheng Tsou
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| | - Chun-Hsien Fei
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Huo-Sheng Chiou
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Yee-Shin Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| | - Woei-Jer Chuang
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jiunn-Jong Wu
- Molecular Biology Consortium, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shuying Wang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
24
|
|
25
|
Lee C, Shin J, Park C. Novel regulatory systemnemRA-gloAfor electrophile reduction inEscherichia coli K-12. Mol Microbiol 2013; 88:395-412. [DOI: 10.1111/mmi.12192] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2013] [Indexed: 01/05/2023]
Affiliation(s)
- Changhan Lee
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology; Yuseong-gu; Daejeon; 305-701; Korea
| | - Jongcheol Shin
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology; Yuseong-gu; Daejeon; 305-701; Korea
| | - Chankyu Park
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology; Yuseong-gu; Daejeon; 305-701; Korea
| |
Collapse
|
26
|
Jacques A, Mettra B, Lebrun V, Latour JM, Sénèque O. On the design of zinc-finger models with cyclic peptides bearing a linear tail. Chemistry 2013; 19:3921-31. [PMID: 23436718 DOI: 10.1002/chem.201204167] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Indexed: 11/07/2022]
Abstract
Cyclic peptides with a linear tail (CPLT) have been successfully used to model two zinc fingers (ZFs) adopting the treble-clef- and loosened zinc-ribbon folds. In this article, we examine the factors that may influence the design of such ZF models: mutations in the sequence, size of the cycle, and size of the tail. For this purpose, several peptides derived from the CPLT-based models of the treble-clef- and loosened zinc-ribbon ZF were synthesized and studied. CPLT-based models appear to be robust toward mutations, accommodate various cycle sizes, and are sensible to the size of the linking region of the tail located between the cycle and the coordinating amino acids. Based on these criteria, we describe the design of a new CPLT-based model for the zinc-ribbon ZFs, LZR , and compare it to a linear analogue, LZR(lin) . The model complex Zn⋅LZR is able to fold correctly around the metal ion contrary to Zn⋅LZR(lin) , suggesting that CPLT-based models are more likely to yield structurally meaningful models of ZF sites than linear peptide models. Finally, we draw some rules that could allow the design of new CPLT-based metallopeptides with a controlled fold.
Collapse
Affiliation(s)
- Aurélie Jacques
- Laboratoire de Chimie et Biologie des Métaux, Equipe de Physicochimie des Métaux en Biologie, UMR 5249 CNRS/CEA-DSV-iRTSV/, Université Joseph Fourier, 17 rue des Martyrs, Grenoble 38054, France
| | | | | | | | | |
Collapse
|
27
|
Liu X, Sun X, Wu Y, Xie C, Zhang W, Wang D, Chen X, Qu D, Gan J, Chen H, Jiang H, Lan L, Yang CG. Oxidation-sensing regulator AbfR regulates oxidative stress responses, bacterial aggregation, and biofilm formation in Staphylococcus epidermidis. J Biol Chem 2013; 288:3739-52. [PMID: 23271738 PMCID: PMC3567629 DOI: 10.1074/jbc.m112.426205] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus epidermidis is a notorious human pathogen that is the major cause of infections related to implanted medical devices. Although redox regulation involving reactive oxygen species is now recognized as a critical component of bacterial signaling and regulation, the mechanism by which S. epidermidis senses and responds to oxidative stress remains largely unknown. Here, we report a new oxidation-sensing regulator, AbfR (aggregation and biofilm formation regulator) in S. epidermidis. An environment of oxidative stress mediated by H(2)O(2) or cumene hydroperoxide markedly up-regulates the expression of abfR gene. Similar to Pseudomonas aeruginosa OspR, AbfR is negatively autoregulated and dissociates from promoter DNA in the presence of oxidants. In vivo and in vitro analyses indicate that Cys-13 and Cys-116 are the key functional residues to form an intersubunit disulfide bond upon oxidation in AbfR. We further show that deletion of abfR leads to a significant induction in H(2)O(2) or cumene hydroperoxide resistance, enhanced bacterial aggregation, and reduced biofilm formation. These effects are mediated by derepression of SERP2195 and gpxA-2 that lie immediately downstream of the abfR gene in the same operon. Thus, oxidative stress likely acts as a signal to modulate S. epidermidis key virulence properties through AbfR.
Collapse
Affiliation(s)
- Xing Liu
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Xiaoxu Sun
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Youcong Wu
- the Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institute of Biomedical Sciences, Shanghai Medical School of Fudan University, Shanghai 200032, China
| | - Cen Xie
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Wenru Zhang
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Dan Wang
- the Coordination Chemistry Institute and the State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and
| | - Xiaoyan Chen
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Di Qu
- the Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Institute of Medical Microbiology and Institute of Biomedical Sciences, Shanghai Medical School of Fudan University, Shanghai 200032, China
| | - Jianhua Gan
- the School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Hao Chen
- the Coordination Chemistry Institute and the State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China, and
| | - Hualiang Jiang
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Lefu Lan
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China, , To whom correspondence may be addressed. Tel.: 86-21-50803109; Fax: 86-21-50807088; E-mail:
| | - Cai-Guang Yang
- From the State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China, , To whom correspondence may be addressed. Tel.: 86-21-50806029; Fax: 86-21-50807088; E-mail:
| |
Collapse
|
28
|
Andrews S, Norton I, Salunkhe AS, Goodluck H, Aly WSM, Mourad-Agha H, Cornelis P. Control of iron metabolism in bacteria. Met Ions Life Sci 2013; 12:203-39. [PMID: 23595674 DOI: 10.1007/978-94-007-5561-1_7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Bacteria depend upon iron as a vital cofactor that enables a wide range of key metabolic activities. Bacteria must therefore ensure a balanced supply of this essential metal. To do so, they invest considerable resourse into its acquisition and employ elaborate control mechanisms to eleviate both iron-induced toxitiy as well as iron deficiency. This chapter describes the processes that bacteria engage in maintaining iron homeostasis. The focus is Escherichia coli, as this bacterium provides a well studied example. A summary of the current status of understanding of iron management at the 'omics' level is also presented.
Collapse
Affiliation(s)
- Simon Andrews
- The School of Biological Sciences, The University of Reading, Whiteknights, Reading, RG6 6AJ, UK,
| | | | | | | | | | | | | |
Collapse
|
29
|
Bhat SA, Singh N, Trivedi A, Kansal P, Gupta P, Kumar A. The mechanism of redox sensing in Mycobacterium tuberculosis. Free Radic Biol Med 2012; 53:1625-41. [PMID: 22921590 DOI: 10.1016/j.freeradbiomed.2012.08.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 08/03/2012] [Accepted: 08/03/2012] [Indexed: 12/25/2022]
Abstract
Tuberculosis epidemics have defied constraint despite the availability of effective treatment for the past half-century. Mycobacterium tuberculosis, the causative agent of TB, is continually exposed to a number of redox stressors during its pathogenic cycle. The mechanisms used by Mtb to sense redox stress and to maintain redox homeostasis are central to the success of Mtb as a pathogen. Careful analysis of the Mtb genome has revealed that Mtb lacks classical redox sensors such as FNR, FixL, and OxyR. Recent studies, however, have established that Mtb is equipped with various sophisticated redox sensors that can detect diverse types of redox stress, including hypoxia, nitric oxide, carbon monoxide, and the intracellular redox environment. Some of these sensors, such as heme-based DosS and DosT, are unique to mycobacteria, whereas others, such as the WhiB proteins and anti-σ factor RsrA, are unique to actinobacteria. This article provides a comprehensive review of the literature on these redox-sensory modules in the context of TB pathogenesis.
Collapse
Affiliation(s)
- Shabir Ahmad Bhat
- Council of Scientific and Industrial Research, Institute of Microbial Technology, Chandigarh 160036, India
| | | | | | | | | | | |
Collapse
|
30
|
Analysis of the organic hydroperoxide response of Chromobacterium violaceum reveals that OhrR is a cys-based redox sensor regulated by thioredoxin. PLoS One 2012; 7:e47090. [PMID: 23071722 PMCID: PMC3469484 DOI: 10.1371/journal.pone.0047090] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 09/10/2012] [Indexed: 12/17/2022] Open
Abstract
Organic hydroperoxides are oxidants generated during bacterial-host interactions. Here, we demonstrate that the peroxidase OhrA and its negative regulator OhrR comprise a major pathway for sensing and detoxifying organic hydroperoxides in the opportunistic pathogen Chromobacterium violaceum. Initially, we found that an ohrA mutant was hypersensitive to organic hydroperoxides and that it displayed a low efficiency for decomposing these molecules. Expression of ohrA and ohrR was specifically induced by organic hydroperoxides. These genes were expressed as monocistronic transcripts and also as a bicistronic ohrR-ohrA mRNA, generating the abundantly detected ohrA mRNA and the barely detected ohrR transcript. The bicistronic transcript appears to be processed. OhrR repressed both the ohrA and ohrR genes by binding directly to inverted repeat sequences within their promoters in a redox-dependent manner. Site-directed mutagenesis of each of the four OhrR cysteine residues indicated that the conserved Cys21 is critical to organic hydroperoxide sensing, whereas Cys126 is required for disulfide bond formation. Taken together, these phenotypic, genetic and biochemical data indicate that the response of C. violaceum to organic hydroperoxides is mediated by OhrA and OhrR. Finally, we demonstrated that oxidized OhrR, inactivated by intermolecular disulfide bond formation, is specifically regenerated via thiol-disulfide exchange by thioredoxin (but not other thiol reducing agents such as glutaredoxin, glutathione and lipoamide), providing a physiological reducing system for this thiol-based redox switch.
Collapse
|
31
|
Garcin P, Delalande O, Zhang JY, Cassier-Chauvat C, Chauvat F, Boulard Y. A transcriptional-switch model for Slr1738-controlled gene expression in the cyanobacterium Synechocystis. BMC STRUCTURAL BIOLOGY 2012; 12:1. [PMID: 22289274 PMCID: PMC3293774 DOI: 10.1186/1472-6807-12-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 01/30/2012] [Indexed: 12/13/2022]
Abstract
BACKGROUND Protein-DNA interactions play a crucial role in the life of biological organisms in controlling transcription, regulation, as well as DNA recombination and repair. The deep understanding of these processes, which requires the atomic description of the interactions occurring between the proteins and their DNA partners is often limited by the absence of a 3D structure of such complexes. RESULTS In this study, using a method combining sequence homology, structural analogy modeling and biochemical data, we first build the 3D structure of the complex between the poorly-characterized PerR-like regulator Slr1738 and its target DNA, which controls the defences against metal and oxidative stresses in Synechocystis. In a second step, we propose an expanded version of the Slr1738-DNA structure, which accommodates the DNA binding of Slr1738 multimers, a feature likely operating in the complex Slr1738-mediated regulation of stress responses. Finally, in agreement with experimental data we present a 3D-structure of the Slr1738-DNA complex resulting from the binding of multimers of the FUR-like regulator onto its target DNA that possesses internal repeats. CONCLUSION Using a combination of different types of data, we build and validate a relevant model of the tridimensional structure of a biologically important protein-DNA complex. Then, based on published observations, we propose more elaborated multimeric models that may be biologically important to understand molecular mechanisms.
Collapse
Affiliation(s)
- Paul Garcin
- CEA, Institut de Biologie et de Technologies de Saclay, Service de Biologie Intégrative et Génétique Moléculaire, LBI, CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
| | - Olivier Delalande
- CEA, Institut de Biologie et de Technologies de Saclay, Service de Biologie Intégrative et Génétique Moléculaire, LBI, CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
| | - Ju-Yuan Zhang
- CEA, Institut de Biologie et de Technologies de Saclay, Service de Biologie Intégrative et Génétique Moléculaire, LBI, CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
| | - Corinne Cassier-Chauvat
- CEA, Institut de Biologie et de Technologies de Saclay, Service de Biologie Intégrative et Génétique Moléculaire, LBI, CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
- CNRS, URA 2096, F-91191 Gif sur Yvette CEDEX, France
| | - Franck Chauvat
- CEA, Institut de Biologie et de Technologies de Saclay, Service de Biologie Intégrative et Génétique Moléculaire, LBI, CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
| | - Yves Boulard
- CEA, Institut de Biologie et de Technologies de Saclay, Service de Biologie Intégrative et Génétique Moléculaire, LBI, CEA-Saclay, F-91191 Gif sur Yvette CEDEX, France
| |
Collapse
|
32
|
Clair G, Armengaud J, Duport C. Restricting fermentative potential by proteome remodeling: an adaptive strategy evidenced in Bacillus cereus. Mol Cell Proteomics 2012; 11:M111.013102. [PMID: 22232490 DOI: 10.1074/mcp.m111.013102] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Pathogenesis hinges on successful colonization of the gastrointestinal (GI) tract by pathogenic facultative anaerobes. The GI tract is a carbohydrate-limited environment with varying oxygen availability and oxidoreduction potential (ORP). How pathogenic bacteria are able to adapt and grow in these varying conditions remains a key fundamental question. Here, we designed a system biology-inspired approach to pinpoint the key regulators allowing Bacillus cereus to survive and grow efficiently under low ORP anoxic conditions mimicking those encountered in the intestinal lumen. We assessed the proteome components using high throughput nanoLC-MS/MS techniques, reconstituted the main metabolic circuits, constructed ΔohrA and ΔohrR mutants, and analyzed the impacts of ohrA and ohrR disruptions by a novel round of shotgun proteomics. Our study revealed that OhrR and OhrA are crucial to the successful adaptation of B. cereus to the GI tract environment. Specifically, we showed that B. cereus restricts its fermentative growth under low ORP anaerobiosis and sustains efficient aerobic respiratory metabolism, motility, and stress response via OhrRA-dependent proteome remodeling. Finally, our results introduced a new adaptive strategy where facultative anaerobes prefer to restrict their fermentative potential for a long term benefit.
Collapse
Affiliation(s)
- Gérémy Clair
- Université d'Avignon et des Pays de Vaucluse, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France
| | | | | |
Collapse
|
33
|
Derepression of the Bacillus subtilis PerR peroxide stress response leads to iron deficiency. J Bacteriol 2011; 194:1226-35. [PMID: 22194458 DOI: 10.1128/jb.06566-11] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The Bacillus subtilis PerR repressor regulates the adaptive response to peroxide stress. The PerR regulon includes the major vegetative catalase (katA), an iron storage protein (mrgA), an alkylhydroperoxide reductase (ahpCF), a zinc uptake system (zosA), heme biosynthesis enzymes (hemAXCDBL), the iron uptake repressor (fur), and perR itself. A perR null strain is resistant to hydrogen peroxide, accumulates a porphyrin-like compound, and grows very slowly. The poor growth of the perR mutant can be largely accounted for by the elevated expression of two proteins: the KatA catalase and Fur. Genetic studies support a model in which poor growth of the perR null mutant is due to elevated repression of iron uptake by Fur, exacerbated by heme sequestration by the abundant catalase protein. Analysis of the altered-function allele perR991 further supports a link between PerR and iron homeostasis. Strains containing perR991 are peroxide resistant but grow nearly as well as the wild type. Unlike a perR null allele, the perR991 allele (F51S) derepresses KatA, but not Fur, which likely accounts for its comparatively rapid growth.
Collapse
|
34
|
ROS-Mediated Signalling in Bacteria: Zinc-Containing Cys-X-X-Cys Redox Centres and Iron-Based Oxidative Stress. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2012:605905. [PMID: 21977318 PMCID: PMC3184428 DOI: 10.1155/2012/605905] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 07/15/2011] [Accepted: 07/20/2011] [Indexed: 01/26/2023]
Abstract
Bacteria are permanently in contact with reactive oxygen species (ROS), both over the course of their life cycle as well that present in their environment. These species cause damage to proteins, lipids, and nucleotides, negatively impacting the organism. To detect these ROS molecules and to stimulate the expression of proteins involved in antioxidative stress response, bacteria use a number of different protein-based regulatory and sensory systems. ROS-based stress detection mechanisms induce posttranslational modifications, resulting in overall conformational and structural changes within sensory proteins. The subsequent structural rearrangements result in changes of protein activity, which lead to regulated and appropriate response on the transcriptional level. Many bacterial enzymes and regulatory proteins possess a conserved signature, the zinc-containing redox centre Cys-X-X-Cys in which a disulfide bridge is formed upon oxidative stress. Other metal-dependent oxidative modifications of amino acid side-chains (dityrosines, 2-oxo-histidines, or carbonylation) also modulate the activity of redox-sensitive proteins. Using molecular biology, biochemistry, biophysical, and structure biology tools, molecular mechanisms involved in sensing and response to oxidative stress have been elucidated in detail. In this review, we analyze some examples of bacterial redox-sensing proteins involved in antioxidative stress response and focus further on the currently known molecular mechanism of function.
Collapse
|
35
|
Winter T, Winter J, Polak M, Kusch K, Mäder U, Sietmann R, Ehlbeck J, van Hijum S, Weltmann KD, Hecker M, Kusch H. Characterization of the global impact of low temperature gas plasma on vegetative microorganisms. Proteomics 2011; 11:3518-30. [DOI: 10.1002/pmic.201000637] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 04/29/2011] [Accepted: 06/08/2011] [Indexed: 01/19/2023]
|
36
|
Abstract
Exposure to hydrogen peroxide (H(2)O(2)) and other reactive oxygen species is a universal feature of life in an aerobic environment. Bacteria express enzymes to detoxify H(2)O(2) and to repair the resulting damage, and their synthesis is typically regulated by redox-sensing transcription factors. The best characterized bacterial peroxide-sensors are Escherichia coli OxyR and Bacillus subtilis PerR. Analysis of their regulons has revealed that, in addition to inducible detoxification enzymes, adaptation to H(2)O(2) is mediated by modifications of metal ion homeostasis. Analogous adaptations appear to be present in other bacteria as here reviewed for Deinococcus radiodurans, Neisseria gonorrhoeae, Streptococcus pyogenes, and Bradyrhizobium japonicum. As a general theme, peroxide stress elicits changes in cytosolic metal distribution with the net effect of reducing the damage caused by reactive ferrous iron. Iron levels are reduced by repression of uptake, sequestration in storage proteins, and incorporation into metalloenzymes. In addition, peroxide-inducible transporters elevate cytosolic levels of Mn(II) and/or Zn(II) that can displace ferrous iron from sensitive targets. Although bacteria differ significantly in the detailed mechanisms employed to modulate cytosolic metal levels, a high Mn:Fe ratio has emerged as one key correlate of reactive oxygen species resistance.
Collapse
Affiliation(s)
- Melinda J Faulkner
- Department of Microbiology, Cornell University, Ithaca, New York 14853-8101, USA
| | | |
Collapse
|
37
|
Cornelis P, Wei Q, Andrews SC, Vinckx T. Iron homeostasis and management of oxidative stress response in bacteria. Metallomics 2011; 3:540-9. [PMID: 21566833 DOI: 10.1039/c1mt00022e] [Citation(s) in RCA: 200] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Iron is both an essential nutrient for the growth of microorganisms, as well as a dangerous metal due to its capacity to generate reactive oxygen species (ROS) via the Fenton reaction. For these reasons, bacteria must tightly control the uptake and storage of iron in a manner that restricts the build-up of ROS. Therefore, it is not surprising to find that the control of iron homeostasis and responses to oxidative stress are coordinated. The mechanisms concerned with these processes, and the interactions involved, are the subject of this review.
Collapse
Affiliation(s)
- Pierre Cornelis
- Microbial Interactions, Department of Molecular and Cellular Interactions, VIB and Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium.
| | | | | | | |
Collapse
|
38
|
Abstract
Diverse mechanisms for pH sensing and cytoplasmic pH homeostasis enable most bacteria to tolerate or grow at external pH values that are outside the cytoplasmic pH range they must maintain for growth. The most extreme cases are exemplified by the extremophiles that inhabit environments with a pH of below 3 or above 11. Here, we describe how recent insights into the structure and function of key molecules and their regulators reveal novel strategies of bacterial pH homeostasis. These insights may help us to target certain pathogens more accurately and to harness the capacities of environmental bacteria more efficiently.
Collapse
Affiliation(s)
- Terry A. Krulwich
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, Box 1603, 1 Gustave L. Levy Place, New York, NY 10029, USA; Tel. 212-241-7280; Fax. 212-996-7214
| | - George Sachs
- Departments of Physiology and Medicine, David Geffen School of Medicine at UCLA, 405 Hilgard Ave., Los Angeles, California 90024, USA Tel. 310-268-3923, Fax 310-312-9478
| | - Etana Padan
- Alexander Silberman Institute of Life Sciences, Hebrew University, Jerusalem 91904, Israel, Tel. 972 2 6585094, Fax 972 2 658947
| |
Collapse
|
39
|
Abstract
Coping with oxidative stress originating from oxidizing compounds or reactive oxygen species (ROS), associated with the exposure to agents that cause environmental stresses, is one of the prerequisites for an aerobic lifestyle of Bacillus spp. such as B. subtilis, B. cereus and B. anthracis. This minireview highlights novel insights in the primary oxidative stress response caused by oxidizing compounds including hydrogen peroxide and the secondary oxidative stress responses apparent upon exposure to a range of agents and conditions leading to environmental stresses such as antibiotics, heat and acid. Insights in the pathways and damaging radicals involved have been compiled based among others on transcriptome studies, network analyses and fluorescence techniques for detection of ROS at single cell level. Exploitation of the current knowledge for the control of spoilage and pathogenic bacteria is discussed.
Collapse
Affiliation(s)
- Maarten Mols
- Laboratory of Food Microbiology, Wageningen University, Wageningen, The Netherlands.
| | | |
Collapse
|