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Key role for the alternative sigma factor, SigH, in the intracellular life of Mycobacterium avium subsp. paratuberculosis during macrophage stress. Infect Immun 2013; 81:2242-57. [PMID: 23569115 DOI: 10.1128/iai.01273-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium avium subsp. paratuberculosis causes Johne's disease, an enteric infection in cattle and other ruminants, greatly afflicting the dairy industry worldwide. Once inside the cell, M. avium subsp. paratuberculosis is known to survive harsh microenvironments, especially those inside activated macrophages. To improve our understanding of M. avium subsp. paratuberculosis pathogenesis, we examined phagosome maturation associated with transcriptional responses of M. avium subsp. paratuberculosis during macrophage infection. Monitoring cellular markers, only live M. avium subsp. paratuberculosis bacilli were able to prevent phagosome maturation and reduce its acidification. On the transcriptional level, over 300 M. avium subsp. paratuberculosis genes were significantly and differentially regulated in both naive and IFN-γ-activated macrophages. These genes include the sigma factor H (sigH) that was shown to be important for M. avium subsp. paratuberculosis survival inside gamma interferon (IFN-γ)-activated bovine macrophages. Interestingly, an sigH-knockout mutant showed increased sensitivity to a sustained level of thiol-specific oxidative stress. Large-scale RNA sequence analysis revealed that a large number of genes belong to the sigH regulon, especially following diamide stress. Genes involved in oxidative stress and virulence were among the induced genes in the sigH regulon with a putative consensus sequence for SigH binding that was recognized in a subset of these genes (n = 30), suggesting direct regulation by SigH. Finally, mice infections showed a significant attenuation of the ΔsigH mutant compared to its parental strain, suggesting a role for sigH in M. avium subsp. paratuberculosis virulence. Such analysis could identify potential targets for further testing as vaccine candidates against Johne's disease.
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Nambu T, Yamane K, Yamanaka T, Mashimo C, Maruyama H, Yoshida M, Hayashi H, Leung KP, Fukushima H. Identification of disulphide stress-responsive extracytoplasmic function sigma factors in Rothia mucilaginosa. Arch Oral Biol 2013; 58:681-9. [PMID: 23399044 DOI: 10.1016/j.archoralbio.2012.10.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 08/21/2012] [Accepted: 10/23/2012] [Indexed: 11/17/2022]
Abstract
Rothia mucilaginosa is known as a member of commensal bacterial flora in the oral cavity and has received attention as a potential opportunistic pathogen. We previously determined the genomic sequence of R. mucilaginosa DY-18, a clinical strain with biofilm-like structures isolated from an infected root canal of a tooth with persistent apical periodontitis. We found that the DY-18 genome had only two sigma factor genes that encoded the primary and extracytoplasmic function (ECF) sigma factors. Genomic analysis on the available database of R. mucilaginosa ATCC 25296 (a type strain for R. mucilaginosa) revealed that ATCC 25296 has three sigma factors: one primary sigma factor and two ECF sigma factors, one of which was highly homologous to that of DY-18. ECF sigma factors play an important role in the response to environmental stress and to the production of virulence factors. Therefore, we first examined gene-encoding sigma factors on R. mucilaginosa genome in silico. The homologous ECF sigma factors found in strains DY-18 and ATCC 25296 formed a distinct SigH (SigR) clade in a phylogenetic tree and their cognate anti-sigma factor has a HXXXCXXC motif known to respond against disulphide stress. Quantitative reverse transcription polymerase chain reaction (PCR) and microarray analysis showed that the transcriptional levels of sigH were markedly up-regulated under disulphide stress in both strains. Microarray data also demonstrated that several oxidative-stress-related genes (thioredoxin, mycothione reductase, reductase and oxidoreductase) were significantly up-regulated under the diamide stress. On the basis of these results, we conclude that the alternative sigma factor SigH of R. mucilaginosa is a candidate regulator in the redox state.
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Affiliation(s)
- Takayuki Nambu
- Department of Bacteriology, Osaka Dental University, 8-1 Kuzuha-Hanazono, Hirakata, 573-1121 Japan.
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Dharmaraja AT, Alvala M, Sriram D, Yogeeswari P, Chakrapani H. Design, synthesis and evaluation of small molecule reactive oxygen species generators as selective Mycobacterium tuberculosis inhibitors. Chem Commun (Camb) 2013; 48:10325-7. [PMID: 22977884 DOI: 10.1039/c2cc35343a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Here, we report 5-hydroxy-1,2,3,4,4a,9a-hexahydro-1,4-ethano-9,10-anthraquinone (13), a small molecule generating reactive oxygen species (ROS) in pH 7.4 buffer under ambient aerobic conditions that has selective and potent Mycobacterium tuberculosis growth inhibitory activity.
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Affiliation(s)
- Allimuthu T Dharmaraja
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Pune 411 008, Maharashtra, India
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54
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Diversity of Frankia Strains, Actinobacterial Symbionts of Actinorhizal Plants. SOIL BIOLOGY 2013. [DOI: 10.1007/978-3-642-39317-4_7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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55
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Strakova E, Bobek J, Zikova A, Rehulka P, Benada O, Rehulkova H, Kofronova O, Vohradsky J. Systems insight into the spore germination of Streptomyces coelicolor. J Proteome Res 2012. [PMID: 23181467 DOI: 10.1021/pr300980v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An example of bacterium, which undergoes a complex development, is the genus of Streptomyces whose importance lies in their wide capacity to produce secondary metabolites, including antibiotics. In this work, a proteomic approach was applied to the systems study of germination as a transition from dormancy to the metabolically active stage. The protein expression levels were examined throughout the germination time course, the kinetics of the accumulated and newly synthesized proteins were clustered, and proteins detected in each group were identified. Altogether, 104 2DE gel images at 13 time points, from dormant state until 5.5 h of growth, were analyzed. The mass spectrometry identified proteins were separated into functional groups and their potential roles during germination were further assessed. The results showed that the full competence of spores to effectively undergo active metabolism is derived from the sporulation step, which facilitates the rapid initiation of global protein expression during the first 10 min of cultivation. Within the first hour, the majority of proteins were synthesized. From this stage, the full capability of regulatory mechanisms to respond to environmental cues is presumed. The obtained results might also provide a data source for further investigations of the process of germination.
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Affiliation(s)
- Eva Strakova
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Bioinformatics, Vídeňská 1083, 142 20 Prague 4, Czech Republic
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Brugarolas P, Movahedzadeh F, Wang Y, Zhang N, Bartek IL, Gao YN, Voskuil MI, Franzblau SG, He C. The oxidation-sensing regulator (MosR) is a new redox-dependent transcription factor in Mycobacterium tuberculosis. J Biol Chem 2012; 287:37703-12. [PMID: 22992749 DOI: 10.1074/jbc.m112.388611] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mycobacterium tuberculosis thrives in oxidative environments such as the macrophage. To survive, the bacterium must sense and adapt to the oxidative conditions. Several antioxidant defenses including a thick cell wall, millimolar concentrations of small molecule thiols, and protective enzymes are known to help the bacterium withstand the oxidative stress. However, oxidation-sensing regulators that control these defenses have remained elusive. In this study, we report a new oxidation-sensing regulator, Rv1049 or MosR (M. tuberculosis oxidation-sensing regulator). MosR is a transcriptional repressor of the MarR family, which, similarly to Bacillus subtilis OhrR and Staphylococcus aureus MgrA, dissociates from DNA in the presence of oxidants, enabling transcription. MosR senses oxidation through a pair of cysteines near the N terminus (Cys-10 and Cys-12) that upon oxidation forms a disulfide bond. Disulfide formation rearranges a network of hydrogen bonds, which leads to a large conformational change of the protein and dissociation from DNA. MosR has been shown previously to play an important role in survival of the bacterium in the macrophage. In this study, we show that the main role of MosR is to up-regulate expression of rv1050 (a putative exported oxidoreductase that has not yet been characterized) in response to oxidants and propose that it is through this role that MosR contributes to the bacterium survival in the macrophage.
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Affiliation(s)
- Pedro Brugarolas
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
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57
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Busche T, Silar R, Pičmanová M, Pátek M, Kalinowski J. Transcriptional regulation of the operon encoding stress-responsive ECF sigma factor SigH and its anti-sigma factor RshA, and control of its regulatory network in Corynebacterium glutamicum. BMC Genomics 2012; 13:445. [PMID: 22943411 PMCID: PMC3489674 DOI: 10.1186/1471-2164-13-445] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 08/22/2012] [Indexed: 02/02/2023] Open
Abstract
Background The expression of genes in Corynebacterium glutamicum, a Gram-positive non-pathogenic bacterium used mainly for the industrial production of amino acids, is regulated by seven different sigma factors of RNA polymerase, including the stress-responsive ECF-sigma factor SigH. The sigH gene is located in a gene cluster together with the rshA gene, putatively encoding an anti-sigma factor. The aim of this study was to analyze the transcriptional regulation of the sigH and rshA gene cluster and the effects of RshA on the SigH regulon, in order to refine the model describing the role of SigH and RshA during stress response. Results Transcription analyses revealed that the sigH gene and rshA gene are cotranscribed from four sigH housekeeping promoters in C. glutamicum. In addition, a SigH-controlled rshA promoter was found to only drive the transcription of the rshA gene. To test the role of the putative anti-sigma factor gene rshA under normal growth conditions, a C. glutamicum rshA deletion strain was constructed and used for genome-wide transcription profiling with DNA microarrays. In total, 83 genes organized in 61 putative transcriptional units, including those previously detected using sigH mutant strains, exhibited increased transcript levels in the rshA deletion mutant compared to its parental strain. The genes encoding proteins related to disulphide stress response, heat stress proteins, components of the SOS-response to DNA damage and proteasome components were the most markedly upregulated gene groups. Altogether six SigH-dependent promoters upstream of the identified genes were determined by primer extension and a refined consensus promoter consisting of 45 original promoter sequences was constructed. Conclusions The rshA gene codes for an anti-sigma factor controlling the function of the stress-responsive sigma factor SigH in C. glutamicum. Transcription of rshA from a SigH-dependent promoter may serve to quickly shutdown the SigH-dependent stress response after the cells have overcome the stress condition. Here we propose a model of the regulation of oxidative and heat stress response including redox homeostasis by SigH, RshA and the thioredoxin system.
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Affiliation(s)
- Tobias Busche
- Centrum für Biotechnologie, Universität Bielefeld, 33594, Bielefeld, Germany
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Casonato S, Cervantes Sánchez A, Haruki H, Rengifo González M, Provvedi R, Dainese E, Jaouen T, Gola S, Bini E, Vicente M, Johnsson K, Ghisotti D, Palù G, Hernández-Pando R, Manganelli R. WhiB5, a transcriptional regulator that contributes to Mycobacterium tuberculosis virulence and reactivation. Infect Immun 2012; 80:3132-44. [PMID: 22733573 PMCID: PMC3418748 DOI: 10.1128/iai.06328-11] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 06/05/2012] [Indexed: 11/20/2022] Open
Abstract
The proteins belonging to the WhiB superfamily are small global transcriptional regulators typical of actinomycetes. In this paper, we characterize the role of WhiB5, a Mycobacterium tuberculosis protein belonging to this superfamily. A null mutant was constructed in M. tuberculosis H37Rv and was shown to be attenuated during both progressive and chronic mouse infections. Mice infected with the mutant had smaller bacillary burdens in the lungs but a larger inflammatory response, suggesting a role of WhiB5 in immunomodulation. Most interestingly, the whiB5 mutant was not able to resume growth after reactivation from chronic infection, suggesting that WhiB5 controls the expression of genes involved in this process. The mutant was also more sensitive than the wild-type parental strain to S-nitrosoglutathione (GSNO) and was less metabolically active following prolonged starvation, underscoring the importance of GSNO and starvation in development and maintenance of chronic infection. DNA microarray analysis identified 58 genes whose expression is influenced by WhiB5, including sigM, encoding an alternative sigma factor, and genes encoding the constituents of two type VII secretion systems, namely, ESX-2 and ESX-4.
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Affiliation(s)
- Stefano Casonato
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Padua, Italy
| | - Axel Cervantes Sánchez
- Experimental Pathology Section, Department of Pathology, National Institute of Medical Sciences and Nutrition Salvador Zubiràn, Mexico City, Mexico
| | - Hirohito Haruki
- Institute of Chemical Sciences and Engineering, Laboratory of Protein Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Monica Rengifo González
- Institute of Chemical Sciences and Engineering, Laboratory of Protein Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Elisa Dainese
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Padua, Italy
| | - Thomas Jaouen
- Department of Biomolecular Sciences and Biotechnologies, University of Milan, Milan, Italy
| | - Susanne Gola
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Estela Bini
- Experimental Pathology Section, Department of Pathology, National Institute of Medical Sciences and Nutrition Salvador Zubiràn, Mexico City, Mexico
| | - Miguel Vicente
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Kai Johnsson
- Institute of Chemical Sciences and Engineering, Laboratory of Protein Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Daniela Ghisotti
- Department of Biomolecular Sciences and Biotechnologies, University of Milan, Milan, Italy
| | - Giorgio Palù
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Padua, Italy
| | - Rogelio Hernández-Pando
- Experimental Pathology Section, Department of Pathology, National Institute of Medical Sciences and Nutrition Salvador Zubiràn, Mexico City, Mexico
| | - Riccardo Manganelli
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Padua, Italy
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Averina OV, Zakharevich NV, Danilenko VN. Identification and characterization of WhiB-like family proteins of the Bifidobacterium genus. Anaerobe 2012; 18:421-9. [DOI: 10.1016/j.anaerobe.2012.04.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 04/23/2012] [Accepted: 04/27/2012] [Indexed: 11/30/2022]
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Chawla M, Parikh P, Saxena A, Munshi M, Mehta M, Mai D, Srivastava AK, Narasimhulu KV, Redding KE, Vashi N, Kumar D, Steyn AJC, Singh A. Mycobacterium tuberculosis WhiB4 regulates oxidative stress response to modulate survival and dissemination in vivo. Mol Microbiol 2012; 85:1148-65. [PMID: 22780904 PMCID: PMC3438311 DOI: 10.1111/j.1365-2958.2012.08165.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Host-generated oxidative stress is considered one of the main mechanisms constraining Mycobacterium tuberculosis (Mtb) growth. The redox-sensing mechanisms in Mtb are not completely understood. Here we show that WhiB4 responds to oxygen (O2) and nitric oxide (NO) via its 4Fe-4S cluster and controls the oxidative stress response in Mtb. The WhiB4 mutant (MtbΔwhiB4) displayed an altered redox balance and a reduced membrane potential. Microarray analysis demonstrated that MtbΔwhiB4 overexpresses the antioxidant systems including alkyl hydroperoxidase (ahpC-ahpD) and rubredoxins (rubA-rubB). DNA binding assays showed that WhiB4 [4Fe-4S] cluster is dispensable for DNA binding. However, oxidation of the apo-WhiB4 Cys thiols induced disulphide-linked oligomerization, DNA binding and transcriptional repression, whereas reduction reversed the effect. Furthermore, WhiB4 binds DNA with a preference for GC-rich sequences. Expression analysis showed that oxidative stress repressed whiB4 and induced antioxidants in Mtb, while their hyper-induction was observed in MtbΔwhiB4. MtbΔwhiB4 showed increased resistance to oxidative stress in vitro and enhanced survival inside the macrophages. Lastly, MtbΔwhiB4 displayed hypervirulence in the lungs of guinea pigs, but showed a defect in dissemination to their spleen. These findings suggest that WhiB4 systematically calibrates the activation of oxidative stress response in Mtb to maintain redox balance, and to modulate virulence.
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Affiliation(s)
- Manbeena Chawla
- Immunology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
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61
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Smith LJ, Stapleton MR, Buxton RS, Green J. Structure-function relationships of the Mycobacterium tuberculosis transcription factor WhiB1. PLoS One 2012; 7:e40407. [PMID: 22792304 PMCID: PMC3390391 DOI: 10.1371/journal.pone.0040407] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 06/06/2012] [Indexed: 11/30/2022] Open
Abstract
Background Members of the WhiB-like (Wbl) protein family possess iron-sulfur clusters and are implicated in the regulation of developmental processes in Actinomycetes. Mycobacterium tuberculosis possesses seven Wbl proteins. The [4Fe-4S] cluster of M. tuberculosis WhiB1 is relatively insensitive to O2 but very sensitive to nitric oxide (NO). Nitric oxide nitrosylates the WhiB1 iron-sulfur cluster and promotes DNA-binding; the apo-forms of WhiB1 also bind DNA. However, the molecular requirements for iron-sulfur cluster acquisition and for DNA-binding by WhiB1 are poorly characterized. Methods and Findings WhiB1 variants were created by site-directed mutagenesis and the abilities of the corresponding proteins to acquire an iron-sulfur cluster and/or bind to whiB1 promoter DNA were assessed. All four Cys residues (Cys9, 37, 40, and 46) in the N-terminal region of WhiB1 were required for incorporation of a [4Fe-4S] cluster, whereas a possible alternative cluster ligand Asp13 (by analogy with M. smegmatis WhiB2) was not. The C-terminal region of WhiB1 is predicted to house the DNA-binding domain of the protein consisting of a predicted β-turn (58GVWGG62) followed by two amino acid motifs (72KRRN75 and 78TKAR81) that are conserved in WhiB1 proteins. Gly residues (Gly58, 61 and 62) in the β-turn and positively-charged residues (Lys72, Arg73, Arg74, Lys79 and Arg81) in the downstream conserved regions were required for binding of WhiB1 DNA. Conclusions Site-directed mutagenesis of M. tuberculosis whiB1 and characterization of the corresponding proteins has been used to explore structure-function relationships of the NO-responsive transcription factor WhiB1. This showed that all four conserved Cys residues in the N-terminal region are required for incorporation of iron-sulfur clusters but not for DNA-binding. Analysis of variants with amino acid substitutions in the C-terminal region revealed the crucial roles played by a predicted β-turn and two conserved positively-charged motifs in facilitating DNA-binding, but not iron-sulfur cluster acquisition, by WhiB1.
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Affiliation(s)
- Laura J Smith
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.
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Kim MS, Dufour YS, Yoo JS, Cho YB, Park JH, Nam GB, Kim HM, Lee KL, Donohue TJ, Roe JH. Conservation of thiol-oxidative stress responses regulated by SigR orthologues in actinomycetes. Mol Microbiol 2012; 85:326-44. [PMID: 22651816 DOI: 10.1111/j.1365-2958.2012.08115.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Numerous thiol-reactive compounds cause oxidative stress where cells counteract by activation of survival strategies regulated by thiol-based sensors. In Streptomyces coelicolor, a model actinomycete, a sigma/antisigma pair SigR/RsrA controls the response to thiol-oxidative stress. To unravel its full physiological functions, chromatin immuno-precipitation combined with sequence and transcript analyses were employed to identify 108 SigR target genes in S. coelicolor and to predict orthologous regulons across actinomycetes. In addition to reported genes for thiol homeostasis, protein degradation and ribosome modulation, 64 additional operons were identified suggesting new functions of this global regulator. We demonstrate that SigR maintains the level and activity of the housekeeping sigma factor HrdB during thiol-oxidative stress, a novel strategy for stress responses. We also found that SigR defends cells against UV and thiol-reactive damages, in which repair UvrA takes a part. Using a refined SigR-binding sequence model, SigR orthologues and their targets were predicted in 42 actinomycetes. This revealed a conserved core set of SigR targets to function for thiol homeostasis, protein quality control, possible modulation of transcription and translation, flavin-mediated redox reactions, and Fe-S delivery. The composition of the SigR regulon reveals a robust conserved physiological mechanism to deal with thiol-oxidative stress from bacteria to human.
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Affiliation(s)
- Min-Sik Kim
- Laboratory of Molecular Microbiology, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Korea
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63
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Barzantny H, Schröder J, Strotmeier J, Fredrich E, Brune I, Tauch A. The transcriptional regulatory network of Corynebacterium jeikeium K411 and its interaction with metabolic routes contributing to human body odor formation. J Biotechnol 2012; 159:235-48. [DOI: 10.1016/j.jbiotec.2012.01.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 01/12/2012] [Accepted: 01/17/2012] [Indexed: 01/08/2023]
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64
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Bibb MJ, Domonkos A, Chandra G, Buttner MJ. Expression of the chaplin and rodlin hydrophobic sheath proteins in Streptomyces venezuelae is controlled by σ(BldN) and a cognate anti-sigma factor, RsbN. Mol Microbiol 2012; 84:1033-49. [PMID: 22582857 DOI: 10.1111/j.1365-2958.2012.08070.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The chaplin and rodlin proteins together constitute the major components of the hydrophobic sheath that coats the aerial hyphae and spores in Streptomyces, and mutants lacking the chaplins are unable to erect aerial hyphae and differentiate on minimal media. We have gained insight into the developmental regulation of the chaplin (chp) and rodlin (rdl) genes by exploiting a new model species, Streptomyces venezuelae, which sporulates in liquid culture. Using microarrays, the chaplin and rodlin genes were found to be highly induced during submerged sporulation in a bldN-dependent manner. Using σ(BldN) ChIP-chip, we show that this dependence arises because the chaplin and rodlin genes are direct biochemical targets of σ(BldN) . sven3186 (here named rsbN for regulator of sigma BldN), the gene lying immediately downstream of bldN, was also identified as a target of σ(BldN) . Disruption of rsbN causes precocious sporulation and biochemical experiments demonstrate that RsbN functions as a σ(BldN) -specific anti-sigma factor.
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Affiliation(s)
- Maureen J Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich NR4 7UH, UK.
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65
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Park JS, Lee JY, Kim HJ, Kim ES, Kim P, Kim Y, Lee HS. The role of Corynebacterium glutamicum spiA gene in whcA-mediated oxidative stress gene regulation. FEMS Microbiol Lett 2012; 331:63-9. [DOI: 10.1111/j.1574-6968.2012.02554.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 03/17/2012] [Accepted: 03/18/2012] [Indexed: 11/26/2022] Open
Affiliation(s)
- Joon-Song Park
- Department of Biotechnology and Bioinformatics; Korea University; Jochiwon; Chungnam; Korea
| | - Joo-Young Lee
- Department of Biotechnology and Bioinformatics; Korea University; Jochiwon; Chungnam; Korea
| | - Hyung-Joon Kim
- CJ Research Institute of Biotechnology; CJ Cheiljedang Corporation; Seoul; Korea
| | - Eung-Soo Kim
- Department of Biological Engineering; Inha University; Incheon; Korea
| | - Pil Kim
- Department of Biotechnology; Catholic University of Korea; Bucheon; Gyeonggi; Korea
| | - Younhee Kim
- Department of Oriental Medicine; Semyung University; Checheon; Chungbuk; Korea
| | - Heung-Shick Lee
- Department of Biotechnology and Bioinformatics; Korea University; Jochiwon; Chungnam; Korea
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Darbon E, Martel C, Nowacka A, Pegot S, Moreau PL, Virolle MJ. Transcriptional and preliminary functional analysis of the six genes located in divergence of phoR/phoP in Streptomyces lividans. Appl Microbiol Biotechnol 2012; 95:1553-66. [DOI: 10.1007/s00253-012-3995-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 01/14/2023]
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67
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Chi HW, Huang CC, Chin DH. Thiols Screened by the Neocarzinostatin Protein for Preserving or Detoxifying its Bound Enediyne Antibiotic. Chemistry 2012; 18:6238-49. [DOI: 10.1002/chem.201102825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 01/12/2012] [Indexed: 12/28/2022]
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68
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Stapleton MR, Smith LJ, Hunt DM, Buxton RS, Green J. Mycobacterium tuberculosis WhiB1 represses transcription of the essential chaperonin GroEL2. Tuberculosis (Edinb) 2012; 92:328-32. [PMID: 22464736 PMCID: PMC3430963 DOI: 10.1016/j.tube.2012.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 02/22/2012] [Accepted: 03/05/2012] [Indexed: 11/29/2022]
Abstract
A central feature of TB pathogenesis is the formation of Mycobacterium tuberculosis latent infections that can persist for decades. Nitric oxide produced by infected lung macrophages promotes expression of genes associated with dormancy, and impaired nitric oxide production can lead to reactivation of latent disease. Recently, WhiB1 was identified as a nitric oxide-responsive transcription factor. Here it is shown that apo-WhiB1 binds to groEL2 (Rv0440) promoter DNA. Apo-WhiB1 inhibited transcription from the groEL2 promoter in vitro and the transcript start was located ∼181 bases upstream of the groEL2 start codon. Electrophoretic mobility shift assays with sub-fragments of the groEL2 promoter indicated that the complete Rv0439c-Rv0440 intergenic region was required for WhiB1 binding, suggesting that this region possessed more than one WhiB1-binding site. DNase I footprinting identified a WhiB1-binding region that overlapped the −35 element of the groEL2 promoter. The CRP-family transcription factor Cmr (Rv1675c) was shown to bind the groEL2 promoter and activate transcription in vitro in the presence or absence of cAMP. Therefore, it is suggested that WhiB1 acts to oppose Cmr-mediated cAMP-independent activation of groEL2 expression in the presence of nitric oxide by promoter occlusion.
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Affiliation(s)
- Melanie R Stapleton
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
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69
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Zheng F, Long Q, Xie J. The Function and Regulatory Network of WhiB and WhiB-Like Protein from Comparative Genomics and Systems Biology Perspectives. Cell Biochem Biophys 2012; 63:103-8. [DOI: 10.1007/s12013-012-9348-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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70
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McCormick JR, Flärdh K. Signals and regulators that govern Streptomyces development. FEMS Microbiol Rev 2012; 36:206-31. [PMID: 22092088 PMCID: PMC3285474 DOI: 10.1111/j.1574-6976.2011.00317.x] [Citation(s) in RCA: 192] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2011] [Revised: 10/29/2011] [Accepted: 10/30/2011] [Indexed: 12/16/2022] Open
Abstract
Streptomyces coelicolor is the genetically best characterized species of a populous genus belonging to the gram-positive Actinobacteria. Streptomycetes are filamentous soil organisms, well known for the production of a plethora of biologically active secondary metabolic compounds. The Streptomyces developmental life cycle is uniquely complex and involves coordinated multicellular development with both physiological and morphological differentiation of several cell types, culminating in the production of secondary metabolites and dispersal of mature spores. This review presents a current appreciation of the signaling mechanisms used to orchestrate the decision to undergo morphological differentiation, and the regulators and regulatory networks that direct the intriguing development of multigenomic hyphae first to form specialized aerial hyphae and then to convert them into chains of dormant spores. This current view of S. coelicolor development is destined for rapid evolution as data from '-omics' studies shed light on gene regulatory networks, new genetic screens identify hitherto unknown players, and the resolution of our insights into the underlying cell biological processes steadily improve.
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Affiliation(s)
| | - Klas Flärdh
- Department of Biology, Lund University, Lund, Sweden
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71
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Abstract
Mycobacterium tuberculosis (Mtb) is a metabolically flexible pathogen
that has the extraordinary ability to sense and adapt to the continuously changing host
environment experienced during decades of persistent infection. Mtb is
continually exposed to endogenous reactive oxygen species (ROS) as part of normal aerobic
respiration, as well as exogenous ROS and reactive nitrogen species (RNS) generated by the
host immune system in response to infection. The magnitude of tuberculosis (TB) disease is
further amplified by exposure to xenobiotics from the environment such as cigarette smoke
and air pollution, causing disruption of the intracellular
prooxidant–antioxidant balance. Both oxidative and reductive stresses induce
redox cascades that alter Mtb signal transduction, DNA and RNA synthesis,
protein synthesis and antimycobacterial drug resistance. As reviewed in this article,
Mtb has evolved specific mechanisms to protect itself against
endogenously produced oxidants, as well as defend against host and environmental oxidants
and reductants found specifically within the microenvironments of the lung. Maintaining an
appropriate redox balance is critical to the clinical outcome because several
antimycobacterial prodrugs are only effective upon bioreductive activation. Proper
homeostasis of oxido-reductive systems is essential for Mtb survival,
persistence and subsequent reactivation. The progress and remaining deficiencies in
understanding Mtb redox homeostasis are also discussed.
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72
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Rabyk M, Ostash B, Rebets Y, Walker S, Fedorenko V. Streptomyces ghanaensis pleiotropic regulatory gene wblA(gh) influences morphogenesis and moenomycin production. Biotechnol Lett 2011; 33:2481-6. [PMID: 21858667 DOI: 10.1007/s10529-011-0728-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 08/02/2011] [Indexed: 10/17/2022]
Abstract
The wblA(gh) gene, encoding a homologue of the WhiB-family of proteins, was identified in the sequenced genome of moenomycin producer Streptomyces ghanaensis. Deletion of the gene blocked aerial mycelium sporulation and caused a 230% increase in moenomycins production. S. ghanaensis overexpressing SSFG-01620: a homologue of extracellular protease inhibitor SCO0762, whose expression in Streptomyces coelicolor is down-regulated by wblA: showed deficiencies in sporulation similar to that of wblA(gh) knockout strain. The wblA(gh) gene of S. ghanaensis appears to play a negative role in the control of moenomycin biosynthesis and is essential for sporulation.
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Affiliation(s)
- Mariia Rabyk
- Department of Genetic and Biotechnology, Ivan Franko National University of Lviv, Grushevskogo St. 4, Lviv 79005, Ukraine.
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73
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Abstract
In recent studies of human bacterial pathogens, oxidation sensing and regulation have been shown to impact very diverse pathways that extend beyond inducing antioxidant genes in the bacteria. In fact, some redox-sensitive regulatory proteins act as major regulators of bacteria's adaptability to oxidative stress, an ability that originates from immune host response as well as antibiotic stress. Such proteins play particularly important roles in pathogenic bacteria S. aureus, P. aeruginosa, and M. tuberculosis in part because reactive oxygen species and reactive nitrogen species present significant challenges for pathogens during infection. Herein, we review recent progress toward the identification and understanding of oxidation sensing and regulation in human pathogens. The newly identified redox switches in pathogens are a focus of this review. We will cover several reactive oxygen species-sensing global regulators in both gram-positive and gram-negative pathogenic bacteria in detail. The following discussion of the mechanisms that these proteins employ to sense redox signals through covalent modification of redox active amino acid residues or associated metalloprotein centers will provide further understanding of bacteria pathogenesis, antibiotic resistance, and host-pathogen interaction.
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Affiliation(s)
- Peng R Chen
- Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
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74
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Farhana A, Guidry L, Srivastava A, Singh A, Hondalus MK, Steyn AJC. Reductive stress in microbes: implications for understanding Mycobacterium tuberculosis disease and persistence. Adv Microb Physiol 2011; 57:43-117. [PMID: 21078441 DOI: 10.1016/b978-0-12-381045-8.00002-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is a remarkably successful pathogen that is capable of persisting in host tissues for decades without causing disease. Years after initial infection, the bacilli may resume growth, the outcome of which is active tuberculosis (TB). In order to establish infection, resist host defences and re-emerge, Mtb must coordinate its metabolism with the in vivo environmental conditions and nutrient availability within the primary site of infection, the lung. Maintaining metabolic homeostasis for an intracellular pathogen such as Mtb requires a carefully orchestrated series of oxidation-reduction reactions, which, if unbalanced, generate oxidative or reductive stress. The importance of oxidative stress in microbial pathogenesis has been appreciated and well studied over the past several decades. However, the role of its counterpart, reductive stress, has been largely ignored. Reductive stress is defined as an aberrant increase in reducing equivalents, the magnitude and identity of which is determined by host carbon source utilisation and influenced by the presence of host-generated gases (e.g. NO, CO, O(2) and CO(2)). This increased reductive power must be dissipated for bacterial survival. To recycle reducing equivalents, microbes have evolved unique electron 'sinks' that are distinct for their particular environmental niche. In this review, we describe the specific mechanisms that some microbes have evolved to dispel reductive stress. The intention of this review is to introduce the concept of reductive stress, in tuberculosis research in particular, in the hope of stimulating new avenues of investigation.
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Affiliation(s)
- Aisha Farhana
- Department of Microbiology, University of Alabama at Birmingham, AL, USA
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75
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Fowler-Goldsworthy K, Gust B, Mouz S, Chandra G, Findlay KC, Chater KF. The actinobacteria-specific gene wblA controls major developmental transitions in Streptomyces coelicolor A3(2). MICROBIOLOGY-SGM 2011; 157:1312-1328. [PMID: 21330440 DOI: 10.1099/mic.0.047555-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Streptomyces coelicolor A3(2) sporulation gene whiB is the paradigm of a family of genes (wbl, whiB-like) that are confined to actinobacteria. The chromosome of S. coelicolor contains 11 wbl genes, among which five are conserved in many actinobacteria: whiB itself; whiD, a sporulation gene; wblC, which is required for multi-drug resistance; and wblA and wblE, whose roles had previously been little studied. We succeeded in disrupting wblA and the six non-conserved genes, but could not disrupt wblE. Although mutations in the six non-conserved wbl genes (including some multiple wbl mutants) produced no readily detectable phenotype, mutations in wblA had novel and complex effects. The aerial mycelium of wblA mutants was coloured red, because of the ectopic presence of pigmented antibiotics (actinorhodin and undecylprodigiosin) normally confined to lower parts of wild-type colonies, and consisted almost entirely of non-sporulating, thin, straight filaments, often bundled together in a fibrillar matrix. Rare spore chains were also formed, which exhibited wild-type properties but were genetically still wblA mutants. A wblA mutant achieved higher biomass than the wild-type. Microarray analysis indicated major transcriptional changes in a wblA mutant: using a relatively stringent cut-off, 183 genes were overexpressed, including genes for assimilative primary metabolism and actinorhodin biosynthesis, and 103 were underexpressed, including genes associated with stages of aerial hyphal growth. We suggest that WblA is important in both the slow-down of biomass accumulation and the change from aerial hyphal initial cells to the subapical stem and apical compartments that precede sporulation; and that the mutant aerial mycelium consists of recapitulated defective aerial hyphal initial cells.
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Affiliation(s)
- Kay Fowler-Goldsworthy
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Bertolt Gust
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Sébastien Mouz
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Kim C Findlay
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
| | - Keith F Chater
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK
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76
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Crack JC, Smith LJ, Stapleton MR, Peck J, Watmough NJ, Buttner MJ, Buxton RS, Green J, Oganesyan VS, Thomson AJ, Le Brun NE. Mechanistic insight into the nitrosylation of the [4Fe-4S] cluster of WhiB-like proteins. J Am Chem Soc 2010; 133:1112-21. [PMID: 21182249 PMCID: PMC3117330 DOI: 10.1021/ja109581t] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
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The reactivity of protein bound iron−sulfur clusters with nitric oxide (NO) is well documented, but little is known about the actual mechanism of cluster nitrosylation. Here, we report studies of members of the Wbl family of [4Fe−4S] containing proteins, which play key roles in regulating developmental processes in actinomycetes, including Streptomyces and Mycobacteria, and have been shown to be NO responsive. Streptomyces coelicolor WhiD and Mycobacterium tuberculosis WhiB1 react extremely rapidly with NO in a multiphasic reaction involving, remarkably, 8 NO molecules per [4Fe−4S] cluster. The reaction is 104-fold faster than that observed with O2 and is by far the most rapid iron−sulfur cluster nitrosylation reaction reported to date. An overall stoichiometry of [Fe4S4(Cys)4]2− + 8NO → 2[FeI2(NO)4(Cys)2]0 + S2− + 3S0 has been established by determination of the sulfur products and their oxidation states. Kinetic analysis leads to a four-step mechanism that accounts for the observed NO dependence. DFT calculations suggest the possibility that the nitrosylation product is a novel cluster [FeI4(NO)8(Cys)4]0 derived by dimerization of a pair of Roussin’s red ester (RRE) complexes.
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Affiliation(s)
- Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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77
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Smith LJ, Stapleton MR, Fullstone GJM, Crack JC, Thomson AJ, Le Brun NE, Hunt DM, Harvey E, Adinolfi S, Buxton RS, Green J. Mycobacterium tuberculosis WhiB1 is an essential DNA-binding protein with a nitric oxide-sensitive iron-sulfur cluster. Biochem J 2010; 432:417-27. [PMID: 20929442 PMCID: PMC2992795 DOI: 10.1042/bj20101440] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mycobacterium tuberculosis is a major pathogen that has the ability to establish, and emerge from, a persistent state. Wbl family proteins are associated with developmental processes in actinomycetes, and M. tuberculosis has seven such proteins. In the present study it is shown that the M. tuberculosis H37Rv whiB1 gene is essential. The WhiB1 protein possesses a [4Fe-4S]2+ cluster that is stable in air but reacts rapidly with eight equivalents of nitric oxide to yield two dinuclear dinitrosyl-iron thiol complexes. The [4Fe-4S] form of WhiB1 did not bind whiB1 promoter DNA, but the reduced and oxidized apo-WhiB1, and nitric oxide-treated holo-WhiB1 did bind to DNA. Mycobacterium smegmatis RNA polymerase induced transcription of whiB1 in vitro; however, in the presence of apo-WhiB1, transcription was severely inhibited, irrespective of the presence or absence of the CRP (cAMP receptor protein) Rv3676, which is known to activate whiB1 expression. Footprinting suggested that autorepression of whiB1 is achieved by apo-WhiB1 binding at a region that overlaps the core promoter elements. A model incorporating regulation of whiB1 expression in response to nitric oxide and cAMP is discussed with implications for sensing two important signals in establishing M. tuberculosis infections.
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Affiliation(s)
- Laura J. Smith
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Melanie R. Stapleton
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Gavin J. M. Fullstone
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Jason C. Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Andrew J. Thomson
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Nick E. Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Debbie M. Hunt
- Division of Mycobacterial Research, MRC National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
| | - Evelyn Harvey
- Division of Mycobacterial Research, MRC National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
| | - Salvatore Adinolfi
- Division of Molecular Structure, MRC National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
| | - Roger S. Buxton
- Division of Mycobacterial Research, MRC National Institute for Medical Research, Mill Hill, London, NW7 1AA, UK
| | - Jeffrey Green
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
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78
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Identification and quantification of mycothiol in Actinobacteria by a novel enzymatic method. Appl Microbiol Biotechnol 2010; 88:1393-401. [DOI: 10.1007/s00253-010-2918-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2010] [Revised: 09/06/2010] [Accepted: 09/08/2010] [Indexed: 10/19/2022]
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79
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Bussmann M, Baumgart M, Bott M. RosR (Cg1324), a hydrogen peroxide-sensitive MarR-type transcriptional regulator of Corynebacterium glutamicum. J Biol Chem 2010; 285:29305-18. [PMID: 20643656 PMCID: PMC2937963 DOI: 10.1074/jbc.m110.156372] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Revised: 07/14/2010] [Indexed: 11/06/2022] Open
Abstract
The cg1324 gene (rosR) of Corynebacterium glutamicum encodes a MarR-type transcriptional regulator. By a comparative transcriptome analysis with DNA microarrays of a ΔrosR mutant and the wild type and subsequent EMSAs with purified RosR protein, direct target genes of RosR were identified. The narKGHJI operon, which encodes a nitrate/nitrite transporter and the dissimilatory nitrate reductase complex, was activated by RosR. All other target genes were repressed by RosR. They encode four putative monooxygenases, two putative FMN reductases, a protein of the glutathione S-transferase family, a putative polyisoprenoid-binding protein, and RosR itself. The DNA binding site of RosR was characterized as an 18-bp inverted repeat with the consensus sequence TTGTTGAYRYRTCAACWA. The in vitro DNA binding activity of RosR was reversibly inhibited by the oxidant H(2)O(2). Mutational analysis of the three cysteine residues present in RosR (Cys-64, Cys-92, and Cys-151) showed that these are responsible for the inhibition of DNA binding by H(2)O(2). A deletion mutant (Δcg1322) lacking the putative polyisoprenoid-binding protein showed an increased sensitivity to H(2)O(2), supporting the role of RosR in the oxidative stress response of C. glutamicum.
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Affiliation(s)
- Michael Bussmann
- From the Institut für Biotechnologie 1, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Meike Baumgart
- From the Institut für Biotechnologie 1, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Michael Bott
- From the Institut für Biotechnologie 1, Forschungszentrum Jülich, D-52425 Jülich, Germany
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80
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Den Hengst CD, Tran NT, Bibb MJ, Chandra G, Leskiw BK, Buttner MJ. Genes essential for morphological development and antibiotic production in Streptomyces coelicolor are targets of BldD during vegetative growth. Mol Microbiol 2010; 78:361-79. [DOI: 10.1111/j.1365-2958.2010.07338.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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81
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Schröder J, Tauch A. Transcriptional regulation of gene expression inCorynebacterium glutamicum: the role of global, master and local regulators in the modular and hierarchical gene regulatory network. FEMS Microbiol Rev 2010; 34:685-737. [DOI: 10.1111/j.1574-6976.2010.00228.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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82
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Ehira S, Teramoto H, Inui M, Yukawa H. A novel redox-sensing transcriptional regulator CyeR controls expression of an Old Yellow Enzyme family protein in Corynebacterium glutamicum. MICROBIOLOGY-SGM 2010; 156:1335-1341. [PMID: 20110293 DOI: 10.1099/mic.0.036913-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Corynebacterium glutamicum cgR_2930 (cyeR) encodes a transcriptional regulator of the ArsR family. Its gene product, CyeR, was shown here to repress the expression of cyeR and the cgR_2931 (cye1)-cgR_2932 operon, which is located upstream of cyeR in the opposite orientation. The cye1 gene encodes an Old Yellow Enzyme family protein, members of which have been implicated in the oxidative stress response. CyeR binds to the intergenic region between cyeR and cye1. Expression of cyeR and cye1 is induced by oxidative stress, and the DNA-binding activity of CyeR is impaired by oxidants such as diamide and H(2)O(2). CyeR contains two cysteine residues, Cys-36 and Cys-43. Whereas mutation of the former (C36A) has no effect on the redox regulation of CyeR activity, mutating the latter (C43A, C43S) abolishes the DNA-binding activity of CyeR. Cys-43 of CyeR and its C36A derivative are modified upon treatment with diamide, suggesting an important role for Cys-43 in the redox regulation of CyeR activity. It is concluded that CyeR is a redox-sensing transcriptional regulator that controls cye1 expression.
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Affiliation(s)
- Shigeki Ehira
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Haruhiko Teramoto
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Masayuki Inui
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
| | - Hideaki Yukawa
- Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
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83
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Crack JC, den Hengst CD, Jakimowicz P, Subramanian S, Johnson MK, Buttner MJ, Thomson AJ, Le Brun NE. Characterization of [4Fe-4S]-containing and cluster-free forms of Streptomyces WhiD. Biochemistry 2009; 48:12252-64. [PMID: 19954209 PMCID: PMC2815329 DOI: 10.1021/bi901498v] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
WhiD, a member of the WhiB-like (Wbl) family of iron-sulfur proteins found exclusively within the actinomycetes, is required for the late stages of sporulation in Streptomyces coelicolor. Like all other Wbl proteins, WhiD has not so far been purified in a soluble form that contains a significant amount of cluster, and characterization has relied on cluster-reconstituted protein. Thus, a major goal in Wbl research is to obtain and characterize native protein containing iron-sulfur clusters. Here we report the analysis of S. coelicolor WhiD purified anaerobically from Escherichia coli as a soluble protein containing a single [4Fe-4S](2+) cluster ligated by four cysteines. Upon exposure to oxygen, spectral features associated with the [4Fe-4S] cluster were lost in a slow reaction that unusually yielded apo-WhiD directly without significant concentrations of cluster intermediates. This process was found to be highly pH dependent with an optimal stability observed between pH 7.0 and pH 8.0. Low molecular weight thiols, including a mycothiol analogue and thioredoxin, exerted a small but significant protective effect against WhiD cluster loss, an activity that could be of physiological importance. [4Fe-4S](2+) WhiD was found to react much more rapidly with superoxide than with either oxygen or hydrogen peroxide, which may also be of physiological significance. Loss of the [4Fe-4S] cluster to form apoprotein destabilized the protein fold significantly but did not lead to complete unfolding. Finally, apo-WhiD exhibited negligible activity in an insulin-based disulfide reductase assay, demonstrating that it does not function as a general protein disulfide reductase.
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Affiliation(s)
- Jason C. Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Chris D. den Hengst
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Piotr Jakimowicz
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Sowmya Subramanian
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, GA, 30602-2556
| | - Michael K. Johnson
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia, Athens, GA, 30602-2556
| | - Mark J. Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, UK
| | - Andrew J. Thomson
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Nick E. Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
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84
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Stapleton M, Haq I, Hunt DM, Arnvig KB, Artymiuk PJ, Buxton RS, Green J. Mycobacterium tuberculosis cAMP receptor protein (Rv3676) differs from the Escherichia coli paradigm in its cAMP binding and DNA binding properties and transcription activation properties. J Biol Chem 2009; 285:7016-27. [PMID: 20028978 PMCID: PMC2844151 DOI: 10.1074/jbc.m109.047720] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pathogen Mycobacterium tuberculosis produces a burst of cAMP upon infection of macrophages. Bacterial cyclic AMP receptor proteins (CRP) are transcription factors that respond to cAMP by binding at target promoters when cAMP concentrations increase. Rv3676 (CRP(Mt)) is a CRP family protein that regulates expression of genes (rpfA and whiB1) that are potentially involved in M. tuberculosis persistence and/or emergence from the dormant state. Here, the CRP(Mt) homodimer is shown to bind two molecules of cAMP (one per protomer) at noninteracting sites. Furthermore, cAMP binding by CRP(Mt) was relatively weak, entropy driven, and resulted in a relatively small enhancement in DNA binding. Tandem CRP(Mt)-binding sites (CRP1 at -58.5 and CRP2 at -37.5) were identified at the whiB1 promoter (PwhiB1). In vitro transcription reactions showed that CRP1 is an activating site and that CRP2, which was only occupied in the presence of cAMP or at high CRP(Mt) concentrations in the absence of cAMP, is a repressing site. Binding of CRP(Mt) to CRP1 was not essential for open complex formation but was required for transcription activation. Thus, these data suggest that binding of CRP(Mt) to the PwhiB1 CRP1 site activates transcription at a step after open complex formation. In contrast, high cAMP concentrations allowed occupation of both CRP1 and CRP2 sites, resulting in inhibition of open complex formation. Thus, M. tuberculosis CRP has evolved several distinct characteristics, compared with the Escherichia coli CRP paradigm, to allow it to regulate gene expression against a background of high concentrations of cAMP.
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Affiliation(s)
- Melanie Stapleton
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
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85
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Hugo M, Turell L, Manta B, Botti H, Monteiro G, Netto LES, Alvarez B, Radi R, Trujillo M. Thiol and sulfenic acid oxidation of AhpE, the one-cysteine peroxiredoxin from Mycobacterium tuberculosis: kinetics, acidity constants, and conformational dynamics. Biochemistry 2009; 48:9416-26. [PMID: 19737009 DOI: 10.1021/bi901221s] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Drug resistance and virulence of Mycobacterium tuberculosis are partially related to the pathogen's antioxidant systems. Peroxide detoxification in this bacterium is achieved by the heme-containing catalase peroxidase and different two-cysteine peroxiredoxins. M. tuberculosis genome also codifies for a putative one-cysteine peroxiredoxin, alkyl hydroperoxide reductase E (MtAhpE). Its expression was previously demonstrated at a transcriptional level, and the crystallographic structure of the recombinant protein was resolved under reduced and oxidized states. Herein, we report that the conformation of MtAhpE changed depending on its single cysteine redox state, as reflected by different tryptophan fluorescence properties and changes in quaternary structure. Dynamics of fluorescence changes, complemented by competition kinetic assays, were used to perform protein functional studies. MtAhpE reduced peroxynitrite 2 orders of magnitude faster than hydrogen peroxide (1.9 x 10(7) M(-1) s(-1) vs 8.2 x 10(4) M(-1) s(-1) at pH 7.4 and 25 degrees C, respectively). The latter also caused cysteine overoxidation to sulfinic acid, but at much slower rate constant (40 M(-1) s(-1)). The pK(a) of the thiol in the reduced enzyme was 5.2, more than one unit lower than that of the sulfenic acid in the oxidized enzyme. The pH profile of hydrogen peroxide-mediated thiol and sulfenic acid oxidations indicated thiolate and sulfenate as the reacting species. The formation of sulfenic acid as well as the catalytic peroxidase activity of MtAhpE was demonstrated using the artificial reducing substrate thionitrobenzoate. Taken together, our results indicate that MtAhpE is a relevant component in the antioxidant repertoire of M. tuberculosis probably involved in peroxide and specially peroxynitrite detoxification.
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Affiliation(s)
- Martín Hugo
- Departamento de Bioqumica, Facultad de Medicina, Center for Free Radical and Biomedical Research, Universidad de la República, Montevideo, Uruguay
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86
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Mycobacterium tuberculosis WhiB3 maintains redox homeostasis by regulating virulence lipid anabolism to modulate macrophage response. PLoS Pathog 2009; 5:e1000545. [PMID: 19680450 PMCID: PMC2718811 DOI: 10.1371/journal.ppat.1000545] [Citation(s) in RCA: 222] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 07/16/2009] [Indexed: 11/30/2022] Open
Abstract
The metabolic events associated with maintaining redox homeostasis in Mycobacterium tuberculosis (Mtb) during infection are poorly understood. Here, we discovered a novel redox switching mechanism by which Mtb WhiB3 under defined oxidizing and reducing conditions differentially modulates the assimilation of propionate into the complex virulence polyketides polyacyltrehaloses (PAT), sulfolipids (SL-1), phthiocerol dimycocerosates (PDIM), and the storage lipid triacylglycerol (TAG) that is under control of the DosR/S/T dormancy system. We developed an in vivo radio-labeling technique and demonstrated for the first time the lipid profile changes of Mtb residing in macrophages, and identified WhiB3 as a physiological regulator of virulence lipid anabolism. Importantly, MtbΔwhiB3 shows enhanced growth on medium containing toxic levels of propionate, thereby implicating WhiB3 in detoxifying excess propionate. Strikingly, the accumulation of reducing equivalents in MtbΔwhiB3 isolated from macrophages suggests that WhiB3 maintains intracellular redox homeostasis upon infection, and that intrabacterial lipid anabolism functions as a reductant sink. MtbΔwhiB3 infected macrophages produce higher levels of pro- and anti-inflammatory cytokines, indicating that WhiB3-mediated regulation of lipids is required for controlling the innate immune response. Lastly, WhiB3 binds to pks2 and pks3 promoter DNA independent of the presence or redox state of its [4Fe-4S] cluster. Interestingly, reduction of the apo-WhiB3 Cys thiols abolished DNA binding, whereas oxidation stimulated DNA binding. These results confirmed that WhiB3 DNA binding is reversibly regulated by a thiol-disulfide redox switch. These results introduce a new paradigmatic mechanism that describes how WhiB3 facilitates metabolic switching to fatty acids by regulating Mtb lipid anabolism in response to oxido-reductive stress associated with infection, for maintaining redox balance. The link between the WhiB3 virulence pathway and DosR/S/T signaling pathway conceptually advances our understanding of the metabolic adaptation and redox-based signaling events exploited by Mtb to maintain long-term persistence. Currently, approximately one-third of the world's population is latently infected with Mycobacterium tuberculosis (Mtb), the bacterium that causes tuberculosis (TB). A central question in TB research is to identify the mechanisms that allow the organism to persist for long periods of time in humans. The mycobacterial cell wall has a high lipid content and contains several important lipid groups, including poly- and di-acyltrehaloses (PAT/DAT), sulfolipids (SL-1), and phthiocerol dimycocerosates (PDIM). These lipids are produced and actively secreted during infection to subvert the host immune system, eventually leading to Mtb persistence. We have discovered that the regulatory protein WhiB3 controls the differential production of PAT, DAT, SL-1, and PDIM and the storage lipid triacylglycerol (TAG) in response to fluctuations in the intracellular redox environment. We demonstrated that WhiB3 directly regulates lipid production by binding to the promoter regions of lipid biosynthetic genes in a redox-dependent manner. We also discovered that through this regulatory process, WhiB3 controls fatty acid metabolism and maintains intracellular redox homeostasis by channeling toxic reducing equivalents into lipid anabolism. Thus, our results suggest that Mtb lipid anabolism functions as a reductant sink to neutralize the reductive stress associated with the catabolism of host lipids during infection. These findings may serve as a model foundation for how pathogens adjust their metabolism to cope with stresses encountered during infection.
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87
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Ehira S, Teramoto H, Inui M, Yukawa H. Regulation of Corynebacterium glutamicum heat shock response by the extracytoplasmic-function sigma factor SigH and transcriptional regulators HspR and HrcA. J Bacteriol 2009; 191:2964-72. [PMID: 19270092 PMCID: PMC2681815 DOI: 10.1128/jb.00112-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 02/24/2009] [Indexed: 11/20/2022] Open
Abstract
Heat shock response in Corynebacterium glutamicum was characterized by whole-genome expression analysis using a DNA microarray. It was indicated that heat shock response of C. glutamicum included not only upregulation of heat shock protein (HSP) genes encoding molecular chaperones and ATP-dependent proteases, but it also increased and decreased expression of more than 300 genes related to disparate physiological functions. An extracytoplasmic-function sigma factor, SigH, was upregulated by heat shock. The SigH regulon was defined by gene expression profiling using sigH-disrupted and overexpressing strains in conjunction with mapping of transcription initiation sites. A total of 45 genes, including HSP genes and genes involved in oxidative stress response, were identified as the SigH regulon. Expression of some HSP genes was also upregulated by deletion of the transcriptional regulators HspR and HrcA. HspR represses expression of the clpB and dnaK operons, and HrcA represses expression of groESL1 and groEL2. SigH was shown to play an important role in regulation of heat shock response in concert with HspR and HrcA, but its role is likely restricted to only a part of the regulation of C. glutamicum heat shock response. Upregulation of 18 genes encoding transcriptional regulators by heat shock suggests a complex regulatory network of heat shock response in C. glutamicum.
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Affiliation(s)
- Shigeki Ehira
- Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan
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88
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Ordóñez E, Van Belle K, Roos G, De Galan S, Letek M, Gil JA, Wyns L, Mateos LM, Messens J. Arsenate reductase, mycothiol, and mycoredoxin concert thiol/disulfide exchange. J Biol Chem 2009; 284:15107-16. [PMID: 19286650 DOI: 10.1074/jbc.m900877200] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We identified the first enzymes that use mycothiol and mycoredoxin in a thiol/disulfide redox cascade. The enzymes are two arsenate reductases from Corynebacterium glutamicum (Cg_ArsC1 and Cg_ArsC2), which play a key role in the defense against arsenate. In vivo knockouts showed that the genes for Cg_ArsC1 and Cg_ArsC2 and those of the enzymes of the mycothiol biosynthesis pathway confer arsenate resistance. With steady-state kinetics, arsenite analysis, and theoretical reactivity analysis, we unraveled the catalytic mechanism for the reduction of arsenate to arsenite in C. glutamicum. The active site thiolate in Cg_ArsCs facilitates adduct formation between arsenate and mycothiol. Mycoredoxin, a redox enzyme for which the function was never shown before, reduces the thiol-arseno bond and forms arsenite and a mycothiol-mycoredoxin mixed disulfide. A second molecule of mycothiol recycles mycoredoxin and forms mycothione that, in its turn, is reduced by the NADPH-dependent mycothione reductase. Cg_ArsCs show a low specificity constant of approximately 5 m(-1) s(-1), typically for a thiol/disulfide cascade with nucleophiles on three different molecules. With the in vitro reconstitution of this novel electron transfer pathway, we have paved the way for the study of redox mechanisms in actinobacteria.
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Affiliation(s)
- Efrén Ordóñez
- Department of Molecular Biology, Area of Microbiology, University of León, 24071 León, Spain
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89
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Streptomyces morphogenetics: dissecting differentiation in a filamentous bacterium. Nat Rev Microbiol 2009; 7:36-49. [DOI: 10.1038/nrmicro1968] [Citation(s) in RCA: 465] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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90
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Biosynthesis and functions of mycothiol, the unique protective thiol of Actinobacteria. Microbiol Mol Biol Rev 2008; 72:471-94. [PMID: 18772286 DOI: 10.1128/mmbr.00008-08] [Citation(s) in RCA: 262] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycothiol (MSH; AcCys-GlcN-Ins) is the major thiol found in Actinobacteria and has many of the functions of glutathione, which is the dominant thiol in other bacteria and eukaryotes but is absent in Actinobacteria. MSH functions as a protected reserve of cysteine and in the detoxification of alkylating agents, reactive oxygen and nitrogen species, and antibiotics. MSH also acts as a thiol buffer which is important in maintaining the highly reducing environment within the cell and protecting against disulfide stress. The pathway of MSH biosynthesis involves production of GlcNAc-Ins-P by MSH glycosyltransferase (MshA), dephosphorylation by the MSH phosphatase MshA2 (not yet identified), deacetylation by MshB to produce GlcN-Ins, linkage to Cys by the MSH ligase MshC, and acetylation by MSH synthase (MshD), yielding MSH. Studies of MSH mutants have shown that the MSH glycosyltransferase MshA and the MSH ligase MshC are required for MSH production, whereas mutants in the MSH deacetylase MshB and the acetyltransferase (MSH synthase) MshD produce some MSH and/or a closely related thiol. Current evidence indicates that MSH biosynthesis is controlled by transcriptional regulation mediated by sigma(B) and sigma(R) in Streptomyces coelicolor. Identified enzymes of MSH metabolism include mycothione reductase (disulfide reductase; Mtr), the S-nitrosomycothiol reductase MscR, the MSH S-conjugate amidase Mca, and an MSH-dependent maleylpyruvate isomerase. Mca cleaves MSH S-conjugates to generate mercapturic acids (AcCySR), excreted from the cell, and GlcN-Ins, used for resynthesis of MSH. The phenotypes of MSH-deficient mutants indicate the occurrence of one or more MSH-dependent S-transferases, peroxidases, and mycoredoxins, which are important targets for future studies. Current evidence suggests that several MSH biosynthetic and metabolic enzymes are potential targets for drugs against tuberculosis. The functions of MSH in antibiotic-producing streptomycetes and in bioremediation are areas for future study.
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91
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Jothivasan VK, Hamilton CJ. Mycothiol: synthesis, biosynthesis and biological functions of the major low molecular weight thiol in actinomycetes. Nat Prod Rep 2008; 25:1091-117. [PMID: 19030604 DOI: 10.1039/b616489g] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Actinomycetes produce mycothiol as their major low molecular weight thiol, which parallels the functions of glutathione found in prokaryotes and most Gram-negative bacteria. This review covers progress that has so far been made in terms of its distribution, biosynthesis and metabolic functions, as well as chemical syntheses of mycothiol and alternative substrates and inhibitors of mycothiol biosynthesis and mycothiol-dependent enzymes. 152 references are cited.
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