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Vauclare P, Wulffelé J, Lacroix F, Servant P, Confalonieri F, Kleman JP, Bourgeois D, Timmins J. Stress-induced nucleoid remodeling in Deinococcus radiodurans is associated with major changes in Heat Unstable (HU) protein dynamics. Nucleic Acids Res 2024:gkae379. [PMID: 38742631 DOI: 10.1093/nar/gkae379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 05/16/2024] Open
Abstract
Bacteria have developed a wide range of strategies to respond to stress, one of which is the rapid large-scale reorganization of their nucleoid. Nucleoid associated proteins (NAPs) are believed to be major actors in nucleoid remodeling, but the details of this process remain poorly understood. Here, using the radiation resistant bacterium D. radiodurans as a model, and advanced fluorescence microscopy, we examined the changes in nucleoid morphology and volume induced by either entry into stationary phase or exposure to UV-C light, and characterized the associated changes in mobility of the major NAP in D. radiodurans, the heat-unstable (HU) protein. While both types of stress induced nucleoid compaction, HU diffusion was reduced in stationary phase cells, but was instead increased following exposure to UV-C, suggesting distinct underlying mechanisms. Furthermore, we show that UV-C-induced nucleoid remodeling involves a rapid nucleoid condensation step associated with increased HU diffusion, followed by a slower decompaction phase to restore normal nucleoid morphology and HU dynamics, before cell division can resume. These findings shed light on the diversity of nucleoid remodeling processes in bacteria and underline the key role of HU in regulating this process through changes in its mode of assembly on DNA.
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Affiliation(s)
- Pierre Vauclare
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
| | - Jip Wulffelé
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
| | | | - Pascale Servant
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Fabrice Confalonieri
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | | | | | - Joanna Timmins
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France
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2
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Shee S, Veetil RT, Mohanraj K, Das M, Malhotra N, Bandopadhyay D, Beig H, Birua S, Niphadkar S, Nagarajan SN, Sinha VK, Thakur C, Rajmani RS, Chandra N, Laxman S, Singh M, Samal A, Seshasayee AN, Singh A. Biosensor-integrated transposon mutagenesis reveals rv0158 as a coordinator of redox homeostasis in Mycobacterium tuberculosis. eLife 2023; 12:e80218. [PMID: 37642294 PMCID: PMC10501769 DOI: 10.7554/elife.80218] [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: 05/12/2022] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is evolutionarily equipped to resist exogenous reactive oxygen species (ROS) but shows vulnerability to an increase in endogenous ROS (eROS). Since eROS is an unavoidable consequence of aerobic metabolism, understanding how Mtb manages eROS levels is essential yet needs to be characterized. By combining the Mrx1-roGFP2 redox biosensor with transposon mutagenesis, we identified 368 genes (redoxosome) responsible for maintaining homeostatic levels of eROS in Mtb. Integrating redoxosome with a global network of transcriptional regulators revealed a hypothetical protein (Rv0158) as a critical node managing eROS in Mtb. Disruption of rv0158 (rv0158 KO) impaired growth, redox balance, respiration, and metabolism of Mtb on glucose but not on fatty acids. Importantly, rv0158 KO exhibited enhanced growth on propionate, and the Rv0158 protein directly binds to methylmalonyl-CoA, a key intermediate in propionate catabolism. Metabolite profiling, ChIP-Seq, and gene-expression analyses indicate that Rv0158 manages metabolic neutralization of propionate toxicity by regulating the methylcitrate cycle. Disruption of rv0158 enhanced the sensitivity of Mtb to oxidative stress, nitric oxide, and anti-TB drugs. Lastly, rv0158 KO showed poor survival in macrophages and persistence defect in mice. Our results suggest that Rv0158 is a metabolic integrator for carbon metabolism and redox balance in Mtb.
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Affiliation(s)
- Somnath Shee
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | | | - Karthikeyan Mohanraj
- The Institute of Mathematical Sciences, A CI of Homi Bhabha National InstituteChennaiIndia
| | - Mayashree Das
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | | | | | - Hussain Beig
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Shalini Birua
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Shreyas Niphadkar
- Institute for Stem Cell Science and Regenerative MedicineBangaloreIndia
| | - Sathya Narayanan Nagarajan
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Vikrant Kumar Sinha
- Molecular Biophysics Unit, Indian Institute of Science BangaloreBangaloreIndia
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science BangaloreBangaloreIndia
| | - Raju S Rajmani
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science BangaloreBangaloreIndia
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative MedicineBangaloreIndia
| | - Mahavir Singh
- Molecular Biophysics Unit, Indian Institute of Science BangaloreBangaloreIndia
| | - Areejit Samal
- The Institute of Mathematical Sciences, A CI of Homi Bhabha National InstituteChennaiIndia
| | | | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
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3
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Rao KU, Li P, Welinder C, Tenland E, Gourdon P, Sturegård E, Ho JCS, Godaly G. Mechanisms of a Mycobacterium tuberculosis Active Peptide. Pharmaceutics 2023; 15:pharmaceutics15020540. [PMID: 36839864 PMCID: PMC9958537 DOI: 10.3390/pharmaceutics15020540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
Multidrug-resistant tuberculosis (MDR) continues to pose a threat to public health. Previously, we identified a cationic host defense peptide with activity against Mycobacterium tuberculosis in vivo and with a bactericidal effect against MDR M. tuberculosis at therapeutic concentrations. To understand the mechanisms of this peptide, we investigated its interactions with live M. tuberculosis and liposomes as a model. Peptide interactions with M. tuberculosis inner membranes induced tube-shaped membranous structures and massive vesicle formation, thus leading to bubbling cell death and ghost cell formation. Liposomal studies revealed that peptide insertion into inner membranes induced changes in the peptides' secondary structure and that the membranes were pulled such that they aggregated without permeabilization, suggesting that the peptide has a strong inner membrane affinity. Finally, the peptide targeted essential proteins in M. tuberculosis, such as 60 kDa chaperonins and elongation factor Tu, that are involved in mycolic acid synthesis and protein folding, which had an impact on bacterial proliferation. The observed multifaceted targeting provides additional support for the therapeutic potential of this peptide.
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Affiliation(s)
- Komal Umashankar Rao
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, SE-22362 Lund, Sweden
| | - Ping Li
- Department of Experimental Medical Science, Lund University, SE-22362 Lund, Sweden
| | - Charlotte Welinder
- Swedish National Infrastructure for Biological Mass Spectrometry, Lund University, SE-22362 Lund, Sweden
| | - Erik Tenland
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, SE-22362 Lund, Sweden
| | - Pontus Gourdon
- Department of Experimental Medical Science, Lund University, SE-22362 Lund, Sweden
- Department of Biomedical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Erik Sturegård
- Department of Clinical Microbiology, Institution of Translational Medicine, Lund University, SE-21428 Malmö, Sweden
| | - James C. S. Ho
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637553, Singapore
| | - Gabriela Godaly
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, SE-22362 Lund, Sweden
- Correspondence:
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4
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Choudhary E, Sharma R, Pal P, Agarwal N. Deciphering the Proteomic Landscape of Mycobacterium tuberculosis in Response to Acid and Oxidative Stresses. ACS OMEGA 2022; 7:26749-26766. [PMID: 35936415 PMCID: PMC9352160 DOI: 10.1021/acsomega.2c03092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023]
Abstract
The fundamental to the pathogenicity of Mycobacterium tuberculosis (Mtb) is the modulation in the control mechanisms that play a role in sensing and counteracting the microbicidal milieu encompassing various cellular stresses inside the human host. To understand such changes, we measured the cellular proteome of Mtb subjected to different stresses using a quantitative proteomics approach. We identified defined sets of Mtb proteins that are modulated in response to acid and a sublethal dose of diamide and H2O2 treatments. Notably, proteins involved in metabolic, catalytic, and binding functions are primarily affected under these stresses. Moreover, our analysis led to the observations that during acidic stress Mtb enters into energy-saving mode simultaneously modulating the acid tolerance system, whereas under diamide and H2O2 stresses, there were prominent changes in the biosynthesis and homeostasis pathways, primarily modifying the resistance mechanism in diamide-treated bacteria while causing metabolic arrest in H2O2-treated bacilli. Overall, we delineated the adaptive mechanisms that Mtb may utilize under physiological stresses and possible overlap between the responses to these stress conditions. In addition to offering important protein signatures that can be exploited for future mechanistic studies, our study highlights the importance of proteomics in understanding complex adjustments made by the human pathogen during infection.
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Affiliation(s)
- Eira Choudhary
- Laboratory
of Mycobacterial Genetics, Translational
Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad121001, Haryana, India
- Symbiosis
School of Biomedical Sciences, Symbiosis
International (Deemed University), Pune412115, Maharashtra, India
| | - Rishabh Sharma
- Laboratory
of Mycobacterial Genetics, Translational
Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad121001, Haryana, India
| | - Pramila Pal
- Laboratory
of Mycobacterial Genetics, Translational
Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad121001, Haryana, India
- Jawaharlal
Nehru University, New
Mehrauli Road, New Delhi110067, India
| | - Nisheeth Agarwal
- Laboratory
of Mycobacterial Genetics, Translational
Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad121001, Haryana, India
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5
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WhiB4 Is Required for the Reactivation of Persistent Infection of Mycobacterium marinum in Zebrafish. Microbiol Spectr 2022; 10:e0044321. [PMID: 35266819 PMCID: PMC9045381 DOI: 10.1128/spectrum.00443-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Granulomas are the pathological hallmark of tuberculosis (TB). In individuals with latent TB infection, Mycobacterium tuberculosis cells reside within granulomas in a nonreplicating dormant state, and a portion of them will develop active TB. Little is known on the bacterial mechanisms/factors involved in this process. In this study, we found that WhiB4, an oxygen sensor and a transcription factor, plays a critical role in disease progression and reactivation of Mycobacterium marinum (M. marinum) infection in zebrafish. We show that the whiB4::Tn mutant of M. marinum caused persistent infection in adult zebrafish, which is characterized by the lower but stable bacterial loads, constant number of nonnecrotized granulomas in fewer organs, and reduced inflammation compared to those of zebrafish infected with the wild-type bacteria or the complemented strain. The mutant bacteria in zebrafish were also less responsive to antibiotic treatments. Moreover, the whiB4::Tn mutant was defective in resuscitation from hypoxia-induced dormancy and the DosR regulon was dysregulated in the mutant. Taken together, our results suggest that WhiB4 is a major driver of reactivation from persistent infection. IMPORTANCE About one-quarter of the world’s population has latent TB infection, and 5 to 10% of those individuals will fall ill with TB. Our finding suggests that WhiB4 is an attractive target for the development of novel therapeutics, which may help to prevent the reactivation of latent infection, thereby reducing the incidences of active TB.
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6
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Oliveira MEFAG, Silva YJA, Azevedo LA, Linhares LA, Montenegro LML, Alves S, Amorim RVS. Antimycobacterial compound of chitosan and ethambutol: ultrastructural biological evaluation in vitro against Mycobacterium tuberculosis. Appl Microbiol Biotechnol 2021; 105:9167-9179. [PMID: 34841463 DOI: 10.1007/s00253-021-11690-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/14/2021] [Accepted: 11/08/2021] [Indexed: 11/26/2022]
Abstract
Chitosan (CS) is a promising biopolymer and has been tested as a complement to the action and compensation of toxicity presented by anti-tuberculosis drugs. The present work studied the adjuvant effect of CS with the drug ethambutol (EMB) as a compound (CS-EMB), to explore its antimicrobial and cytotoxic activity, using transmission electron microscopy (TEM), to examine ultracellular changes that represent possible antimycobacterial action of CS on Mycobacterium tuberculosis (Mtb). Antimycobacterial activities were tested against reference strains Mtb ATCC® H37Rv and multidrug resistant (MDR). In vitro cytotoxicity tests were performed on Raw 264.7. For the studied compounds, morphological, ultrastructural, and physical-chemical analyses were performed. Drug-polymer interactions that occur through the H bridges were confirmed by physical-chemical analyses. The CS-EMB compound is stable at pHs of 6.5-7.5, allowing its release at physiological pH. The antibacterial activity (minimum inhibitory concentration) of the CS-EMB compound was 50% greater than that of the EMB in the H37Rv and MDR strains and the ultrastructural changes in the bacilli observed by TEM proved that the CS-EMB compound has a bactericidal action, allowing it to break down the Mtb cell wall. The cytotoxicity of CS-EMB was higher than that of isolated EMB, IC50 279, and 176 μg/mL, respectively. It is concluded that CS-EMB forms a promising composite against strains Mtb H37Rv and multidrug resistant (MDR-TB).Key points• Our study will be the first to observe ultrastructurally the effects of the CS-EMB compound on Mtb cells.• CS-EMB antimicrobial activity in a multidrug-resistant clinical strain.• The CS-EMB compound has promising potential for the development of a new drug to fight tuberculosis.
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Affiliation(s)
- M E F A G Oliveira
- Programa de Pós-Graduação Em Morfotecnologia, Universidade Federal de Pernambuco (UFPE), Recife, PE, 50670-420, Brazil.
| | - Y J A Silva
- Programa de Pós-Graduação Em Ciência de Materiais, Universidade Federal de Pernambuco (UFPE), Recife, PE, 50740-560, Brazil
| | - L A Azevedo
- Programa de Pós-Graduação Em Ciência de Materiais, Universidade Federal de Pernambuco (UFPE), Recife, PE, 50740-560, Brazil
| | - L A Linhares
- Instituto Aggeu Magalhães/Fundação Oswaldo Cruz (IAM/FIOCRUZ), 50740-465, Recife-PE, Brazil
| | - L M L Montenegro
- Instituto Aggeu Magalhães/Fundação Oswaldo Cruz (IAM/FIOCRUZ), 50740-465, Recife-PE, Brazil
| | - S Alves
- Departamento de Química Fundamental (dQF), Universidade Federal de Pernambuco (UFPE), Recife, PE, 50740-560, Brazil
| | - R V S Amorim
- Departamento de Histologia E Embriologia (DHE-CB), Universidade Federal de Pernambuco (UFPE), Recife, PE, 50670-420, Brazil
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7
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Sarkar S, Dey U, Khohliwe TB, Yella VR, Kumar A. Analysis of nucleoid-associated protein-binding regions reveals DNA structural features influencing genome organization in Mycobacterium tuberculosis. FEBS Lett 2021; 595:2504-2521. [PMID: 34387867 DOI: 10.1002/1873-3468.14178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/01/2021] [Accepted: 08/11/2021] [Indexed: 11/10/2022]
Abstract
Nucleoid-Associated Proteins (NAPs) maintain bacterial nucleoid configuration through their architectural properties of DNA bending, wrapping, and bridging. However, the contribution of DNA structural alterations to DNA-NAP recognition at the genomic scale remains unresolved. Present work dissects the DNA sequence, shape and altered structural preferences at a genomic scale for six NAPs in Mycobacterium tuberculosis. Results suggest narrower minor groove width and higher DNA rigidity are marked for the binding sites of EspR and Lsr2, while mIHF, MtHU and NapM have heterogeneous DNA structural predilections. In contrast, WhiB4-DNA binding sites were characterized by wider minor groove width, highly deformable and less curved DNA. This work provides systematic insight into NAP-mediated genome organization as a function of DNA structural features.
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Affiliation(s)
- Sharmilee Sarkar
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
| | - Upalabdha Dey
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
| | | | - Venkata Rajesh Yella
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Andhra Pradesh, India
| | - Aditya Kumar
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, India
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8
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Wan T, Horová M, Beltran DG, Li S, Wong HX, Zhang LM. Structural insights into the functional divergence of WhiB-like proteins in Mycobacterium tuberculosis. Mol Cell 2021; 81:2887-2900.e5. [PMID: 34171298 DOI: 10.1016/j.molcel.2021.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/12/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
WhiB7 represents a distinct subclass of transcription factors in the WhiB-Like (Wbl) family, a unique group of iron-sulfur (4Fe-4S] cluster-containing proteins exclusive to the phylum of Actinobacteria. In Mycobacterium tuberculosis (Mtb), WhiB7 interacts with domain 4 of the primary sigma factor (σA4) in the RNA polymerase holoenzyme and activates genes involved in multiple drug resistance and redox homeostasis. Here, we report crystal structures of the WhiB7:σA4 complex alone and bound to its target promoter DNA at 1.55-Å and 2.6-Å resolution, respectively. These structures show how WhiB7 regulates gene expression by interacting with both σA4 and the AT-rich sequence upstream of the -35 promoter DNA via its C-terminal DNA-binding motif, the AT-hook. By combining comparative structural analysis of the two high-resolution σA4-bound Wbl structures with molecular and biochemical approaches, we identify the structural basis of the functional divergence between the two distinct subclasses of Wbl proteins in Mtb.
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Affiliation(s)
- Tao Wan
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Magdaléna Horová
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Daisy Guiza Beltran
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Shanren Li
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Huey-Xian Wong
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Li-Mei Zhang
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
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9
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Collateral Sensitivity to β-Lactam Drugs in Drug-Resistant Tuberculosis Is Driven by the Transcriptional Wiring of BlaI Operon Genes. mSphere 2021; 6:e0024521. [PMID: 34047652 PMCID: PMC8265638 DOI: 10.1128/msphere.00245-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The evolution of resistance to one antimicrobial can result in enhanced sensitivity to another, known as "collateral sensitivity." This underexplored phenomenon opens new therapeutic possibilities for patients infected with pathogens unresponsive to classical treatments. Intrinsic resistance to β-lactams in Mycobacterium tuberculosis (the causative agent of tuberculosis) has traditionally curtailed the use of these low-cost and easy-to-administer drugs for tuberculosis treatment. Recently, β-lactam sensitivity has been reported in strains resistant to classical tuberculosis therapy, resurging the interest in β-lactams for tuberculosis. However, a lack of understanding of the molecular underpinnings of this sensitivity has delayed exploration in the clinic. We performed gene expression and network analyses and in silico knockout simulations of genes associated with β-lactam sensitivity and genes associated with resistance to classical tuberculosis drugs to investigate regulatory interactions and identify key gene mediators. We found activation of the key inhibitor of β-lactam resistance, blaI, following classical drug treatment as well as transcriptional links between genes associated with β-lactam sensitivity and those associated with resistance to classical treatment, suggesting that regulatory links might explain collateral sensitivity to β-lactams. Our results support M. tuberculosis β-lactam sensitivity as a collateral consequence of the evolution of resistance to classical tuberculosis drugs, mediated through changes to transcriptional regulation. These findings support continued exploration of β-lactams for the treatment of patients infected with tuberculosis strains resistant to classical therapies. IMPORTANCE Tuberculosis remains a significant cause of global mortality, with strains resistant to classical drug treatment considered a major health concern by the World Health Organization. Challenging treatment regimens and difficulty accessing drugs in low-income communities have led to a high prevalence of strains resistant to multiple drugs, making the development of alternative therapies a priority. Although Mycobacterium tuberculosis is naturally resistant to β-lactam drugs, previous studies have shown sensitivity in strains resistant to classical drug treatment, but we currently lack understanding of the molecular underpinnings behind this phenomenon. We found that genes involved in β-lactam susceptibility are activated after classical drug treatment resulting from tight regulatory links with genes involved in drug resistance. Our study supports the hypothesis that β-lactam susceptibility observed in drug-resistant strains results from the underlying regulatory network of M. tuberculosis, supporting further exploration of the use of β-lactams for tuberculosis treatment.
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10
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Zhai Q, Lin C, Duan B, Liu J, Zhang L, Xia B. 1H, 13C, and 15N resonance assignments of reduced apo-WhiB4 from Mycobacterium tuberculosis. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:99-101. [PMID: 33389547 DOI: 10.1007/s12104-020-09989-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
The WhiB4 protein, a member of WhiB-like proteins, plays an important role in the survival and pathology of Mycobacterium tuberculosis (Mtb). As a transcription factor, WhiB4 regulates the expression of genes involved in maintaining redox homeostasis, central metabolism, and respiration. Furthermore, WhiB4 leads to the condensation of mycobacterial nucleoids and is capable of binding to DNA. WhiB4 contains four cysteine residues and exists in multiple forms under different redox environments, including a dimeric holo form with iron-sulfur cluster, multimeric disulfide-linked oxidized apo forms and monomeric reduced apo form. Here, we report the 1H, 13C, 15N chemical shifts of WhiB4 protein in its reduced apo state, providing a basis for the determination of its solution structure.
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Affiliation(s)
- Qiran Zhai
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Chen Lin
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Bo Duan
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Jun Liu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Lu Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Bin Xia
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, School of Life Sciences, Peking University, Beijing, China.
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11
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Ethanol in Combination with Oxidative Stress Significantly Impacts Mycobacterial Physiology. J Bacteriol 2020; 202:JB.00222-20. [PMID: 32928928 DOI: 10.1128/jb.00222-20] [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: 04/24/2020] [Accepted: 09/02/2020] [Indexed: 11/20/2022] Open
Abstract
Here, we investigate the mycobacterial response to the combined stress of an organic oxidant (cumene hydroperoxide [CHP]) and a solvent (ethanol). To understand the interaction between the two stressors, we treated Mycobacterium smegmatis cells to a range of ethanol concentrations (2.5% to 10% [vol/vol]) in combination with a subinhibitory concentration of 1 mM CHP. It was observed that the presence of CHP increases the efficacy of ethanol in inducing rapid cell death. The data further suggest that ethanol reacts with the alkoxy radicals to produce ethanol-derived peroxides. These radicals induce significant membrane damage and lead to cell lysis. The ethanol-derived radicals were primarily recognized by the cells as organic radicals, as was evident by the differential upregulation of the ohr-ohrR genes that function in cells treated with the combination of ethanol and CHP. The role of organic peroxide reductase, Ohr, was further confirmed by the significantly higher sensitivity of the deletion mutant to CHP and the combined stress treatment of CHP and ethanol. Moreover, we also observed the sigma factor σB to be important for the cells treated with ethanol alone as well as the aforementioned combination. A ΔsigB mutant strain had significantly higher susceptibility to the stress conditions. This finding was correlated with the σB-dependent transcriptional regulation of ohr and ohrR In summary, our data indicate that the combination of low levels of ethanol and organic peroxides induce ethanol-derived organic radicals that lead to significant oxidative stress on the cells in a concentration-dependent manner.IMPORTANCE Bacterial response to a combination of stresses can be unexpected and very different compared with that of an individual stress treatment. This study explores the physiological and transcriptional response of mycobacteria in response to the combinatorial treatment of an oxidant with the commonly used solvent ethanol. The presence of a subinhibitory concentration of organic peroxide increases the effectiveness of ethanol by inducing reactive peroxides that destroy the membrane integrity of cells in a significantly short time span. Our work elucidates a mechanism of targeting the complex mycobacterial membrane, which is its primary source of intrinsic resistance. Furthermore, it also demonstrates the importance of exploring the effect of various stress conditions on inducing bacterial clearance.
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12
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Mishra R, Kohli S, Malhotra N, Bandyopadhyay P, Mehta M, Munshi M, Adiga V, Ahuja VK, Shandil RK, Rajmani RS, Seshasayee ASN, Singh A. Targeting redox heterogeneity to counteract drug tolerance in replicating Mycobacterium tuberculosis. Sci Transl Med 2020; 11:11/518/eaaw6635. [PMID: 31723039 DOI: 10.1126/scitranslmed.aaw6635] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 06/26/2019] [Accepted: 10/25/2019] [Indexed: 12/23/2022]
Abstract
The capacity of Mycobacterium tuberculosis (Mtb) to tolerate multiple antibiotics represents a major problem in tuberculosis (TB) management. Heterogeneity in Mtb populations is one of the factors that drives antibiotic tolerance during infection. However, the mechanisms underpinning this variation in bacterial population remain poorly understood. Here, we show that phagosomal acidification alters the redox physiology of Mtb to generate a population of replicating bacteria that display drug tolerance during infection. RNA sequencing of this redox-altered population revealed the involvement of iron-sulfur (Fe-S) cluster biogenesis, hydrogen sulfide (H2S) gas, and drug efflux pumps in antibiotic tolerance. The fraction of the pH- and redox-dependent tolerant population increased when Mtb infected macrophages with actively replicating HIV-1, suggesting that redox heterogeneity could contribute to high rates of TB therapy failure during HIV-TB coinfection. Pharmacological inhibition of phagosomal acidification by the antimalarial drug chloroquine (CQ) eradicated drug-tolerant Mtb, ameliorated lung pathology, and reduced postchemotherapeutic relapse in in vivo models. The pharmacological profile of CQ (C max and AUClast) exhibited no major drug-drug interaction when coadministered with first line anti-TB drugs in mice. Our data establish a link between phagosomal pH, redox metabolism, and drug tolerance in replicating Mtb and suggest repositioning of CQ to shorten TB therapy and achieve a relapse-free cure.
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Affiliation(s)
- Richa Mishra
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Sakshi Kohli
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Nitish Malhotra
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Parijat Bandyopadhyay
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Mansi Mehta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - MohamedHusen Munshi
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Vasista Adiga
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | | | - Radha K Shandil
- Foundation for Neglected Disease Research, Bangalore 560065, India
| | - Raju S Rajmani
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Aswin Sai Narain Seshasayee
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
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13
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Jiang J, Lin C, Zhang J, Wang Y, Shen L, Yang K, Xiao W, Li Y, Zhang L, Liu J. Transcriptome Changes of Mycobacterium marinum in the Process of Resuscitation From Hypoxia-Induced Dormancy. Front Genet 2020; 10:1359. [PMID: 32117415 PMCID: PMC7025489 DOI: 10.3389/fgene.2019.01359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/11/2019] [Indexed: 12/22/2022] Open
Abstract
Nearly one-third of the world's population is latently infected with Mycobacterium tuberculosis (M. tb), which represents a huge disease reservoir for reactivation and a major obstacle for effective control of tuberculosis. During latent infection, M. tb is thought to enter nonreplicative dormant states by virtue of its response to hypoxia and nutrient-deprived conditions. Knowledge of the genetic programs used to facilitate entry into and exit from the nonreplicative dormant states remains incomplete. In this study, we examined the transcriptional changes of Mycobacterium marinum (M. marinum), a pathogenic mycobacterial species closely related to M. tb, at different stages of resuscitation from hypoxia-induced dormancy. RNA-seq analyses were performed on M. marinum cultures recovered at multiple time points after resuscitation. Differentially expressed genes (DEGs) at each time period were identified and analyzed. Co-expression networks of transcription factors and DEGs in each period were constructed. In addition, we performed a weighted gene co-expression network analysis (WGCNA) on all genes and obtained 12 distinct gene modules. Collectively, these data provided valuable insight into the transcriptome changes of M. marinum upon resuscitation as well as gene module function of the bacteria during active metabolism and growth.
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Affiliation(s)
- Jun Jiang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Chen Lin
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Junli Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Yuchen Wang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Lifang Shen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Kunpeng Yang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Wenxuan Xiao
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Yao Li
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Lu Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China.,State Key Laboratory of Genetic Engineering, MOE Engineering Research Center of Gene Technology, School of Life Science, Fudan University, Shanghai, China
| | - Jun Liu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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14
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Shen BA, Landick R. Transcription of Bacterial Chromatin. J Mol Biol 2019; 431:4040-4066. [PMID: 31153903 PMCID: PMC7248592 DOI: 10.1016/j.jmb.2019.05.041] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022]
Abstract
Decades of research have probed the interplay between chromatin (genomic DNA associated with proteins and RNAs) and transcription by RNA polymerase (RNAP) in all domains of life. In bacteria, chromatin is compacted into a membrane-free region known as the nucleoid that changes shape and composition depending on the bacterial state. Transcription plays a key role in both shaping the nucleoid and organizing it into domains. At the same time, chromatin impacts transcription by at least five distinct mechanisms: (i) occlusion of RNAP binding; (ii) roadblocking RNAP progression; (iii) constraining DNA topology; (iv) RNA-mediated interactions; and (v) macromolecular demixing and heterogeneity, which may generate phase-separated condensates. These mechanisms are not mutually exclusive and, in combination, mediate gene regulation. Here, we review the current understanding of these mechanisms with a focus on gene silencing by H-NS, transcription coordination by HU, and potential phase separation by Dps. The myriad questions about transcription of bacterial chromatin are increasingly answerable due to methodological advances, enabling a needed paradigm shift in the field of bacterial transcription to focus on regulation of genes in their native state. We can anticipate answers that will define how bacterial chromatin helps coordinate and dynamically regulate gene expression in changing environments.
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Affiliation(s)
- Beth A Shen
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, United States.
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