1
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Guiza Beltran D, Wan T, Zhang L. WhiB-like proteins: Diversity of structure, function and mechanism. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119787. [PMID: 38879133 PMCID: PMC11365794 DOI: 10.1016/j.bbamcr.2024.119787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/20/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
The WhiB-Like (Wbl) proteins are a large family of iron-sulfur (Fe-S) cluster-containing transcription factors exclusively found in the phylum Actinobacteria, including the notable genera like Mycobacteria, Streptomycetes and Corynebacteria. These proteins play pivotal roles in diverse biological processes, such as cell development, redox stress response and antibiotic resistance. Members of the Wbl family exhibit remarkable diversity in their sequences, structures and functions, attracting great attention since their first discovery. This review highlights the most recent breakthroughs in understanding the structural and mechanistic aspects of Wbl-dependent transcriptional regulation.
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Affiliation(s)
- Daisy Guiza Beltran
- Department of Biochemistry, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA
| | - Tao Wan
- Department of Biochemistry, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA
| | - LiMei Zhang
- Department of Biochemistry, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA; Redox Biology Center, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA.
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2
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Liu Y, Li H, Dai D, He J, Liang Z. Gene Regulatory Mechanism of Mycobacterium Tuberculosis during Dormancy. Curr Issues Mol Biol 2024; 46:5825-5844. [PMID: 38921019 PMCID: PMC11203133 DOI: 10.3390/cimb46060348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/05/2024] [Accepted: 06/07/2024] [Indexed: 06/27/2024] Open
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) complex, is a zoonotic disease that remains one of the leading causes of death worldwide. Latent tuberculosis infection reactivation is a challenging obstacle to eradicating TB globally. Understanding the gene regulatory network of Mtb during dormancy is important. This review discusses up-to-date information about TB gene regulatory networks during dormancy, focusing on the regulation of lipid and energy metabolism, dormancy survival regulator (DosR), White B-like (Wbl) family, Toxin-Antitoxin (TA) systems, sigma factors, and MprAB. We outline the progress in vaccine and drug development associated with Mtb dormancy.
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Affiliation(s)
- Yiduo Liu
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Han Li
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
| | - Dejia Dai
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
| | - Jiakang He
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
| | - Zhengmin Liang
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
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3
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Dechow SJ, Abramovitch RB. Targeting Mycobacterium tuberculosis pH-driven adaptation. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001458. [PMID: 38717801 PMCID: PMC11165653 DOI: 10.1099/mic.0.001458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
Mycobacterium tuberculosis (Mtb) senses and adapts to host environmental cues as part of its pathogenesis. One important cue sensed by Mtb is the acidic pH of its host niche - the macrophage. Acidic pH induces widespread transcriptional and metabolic remodelling in Mtb. These adaptations to acidic pH can lead Mtb to slow its growth and promote pathogenesis and antibiotic tolerance. Mutants defective in pH-dependent adaptations exhibit reduced virulence in macrophages and animal infection models, suggesting that chemically targeting these pH-dependent pathways may have therapeutic potential. In this review, we discuss mechanisms by which Mtb regulates its growth and metabolism at acidic pH. Additionally, we consider the therapeutic potential of disrupting pH-driven adaptations in Mtb and review the growing class of compounds that exhibit pH-dependent activity or target pathways important for adaptation to acidic pH.
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Affiliation(s)
- Shelby J. Dechow
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, MI 48824, USA
| | - Robert B. Abramovitch
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, MI 48824, USA
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4
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Chen YC, Yang X, Wang N, Sampson NS. Uncovering the roles of Mycobacterium tuberculosis melH in redox and bioenergetic homeostasis: implications for antitubercular therapy. mSphere 2024; 9:e0006124. [PMID: 38564709 PMCID: PMC11036813 DOI: 10.1128/msphere.00061-24] [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: 01/30/2024] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
Mycobacterium tuberculosis (Mtb), the pathogenic bacterium that causes tuberculosis, has evolved sophisticated defense mechanisms to counteract the cytotoxicity of reactive oxygen species (ROS) generated within host macrophages during infection. The melH gene in Mtb and Mycobacterium marinum (Mm) plays a crucial role in defense mechanisms against ROS generated during infection. We demonstrate that melH encodes an epoxide hydrolase and contributes to ROS detoxification. Deletion of melH in Mm resulted in a mutant with increased sensitivity to oxidative stress, increased accumulation of aldehyde species, and decreased production of mycothiol and ergothioneine. This heightened vulnerability is attributed to the increased expression of whiB3, a universal stress sensor. The absence of melH also resulted in reduced intracellular levels of NAD+, NADH, and ATP. Bacterial growth was impaired, even in the absence of external stressors, and the impairment was carbon source dependent. Initial MelH substrate specificity studies demonstrate a preference for epoxides with a single aromatic substituent. Taken together, these results highlight the role of melH in mycobacterial bioenergetic metabolism and provide new insights into the complex interplay between redox homeostasis and generation of reactive aldehyde species in mycobacteria. IMPORTANCE This study unveils the pivotal role played by the melH gene in Mycobacterium tuberculosis and in Mycobacterium marinum in combatting the detrimental impact of oxidative conditions during infection. This investigation revealed notable alterations in the level of cytokinin-associated aldehyde, para-hydroxybenzaldehyde, as well as the redox buffer ergothioneine, upon deletion of melH. Moreover, changes in crucial cofactors responsible for electron transfer highlighted melH's crucial function in maintaining a delicate equilibrium of redox and bioenergetic processes. MelH prefers epoxide small substrates with a phenyl substituted substrate. These findings collectively emphasize the potential of melH as an attractive target for the development of novel antitubercular therapies that sensitize mycobacteria to host stress, offering new avenues for combating tuberculosis.
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Affiliation(s)
- Yu-Ching Chen
- Program in Biochemistry and Structural Biology, Stony Brook University, Stony Brook, New York, USA
| | - Xinxin Yang
- Department of Chemistry, Stony Brook University, Stony Brook, New York, USA
| | - Nan Wang
- Department of Chemistry, University of Rochester, Rochester, New York, USA
| | - Nicole S. Sampson
- Department of Chemistry, Stony Brook University, Stony Brook, New York, USA
- Department of Chemistry, University of Rochester, Rochester, New York, USA
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5
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Belardinelli JM, Arora D, Avanzi C, Wheat WH, Bryant JM, Spencer JS, Blundell TL, Parkhill J, Floto RA, Jackson M. Clinically relevant mutations in the PhoR sensor kinase of host-adapted Mycobacterium abscessus isolates impact response to acidic pH and virulence. Microbiol Spectr 2023; 11:e0158823. [PMID: 37874174 PMCID: PMC10715180 DOI: 10.1128/spectrum.01588-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 09/14/2023] [Indexed: 10/25/2023] Open
Abstract
IMPORTANCE Difficult-to-treat pulmonary infections caused by nontuberculous mycobacteria of the Mycobacterium abscessus group have been steadily increasing in the USA and globally. Owing to the relatively recent recognition of M. abscessus as a human pathogen, basic and translational research to address critical gaps in diagnosis, treatment, and prevention of diseases caused by this microorganism has been lagging behind that of the better-known mycobacterial pathogen, Mycobacterium tuberculosis. To begin unraveling the molecular mechanisms of pathogenicity of M. abscessus, we here focus on the study of a two-component regulator known as PhoPR which we found to be under strong evolutionary pressure during human lung infection. We show that PhoPR is activated at acidic pH and serves to regulate a defined set of genes involved in host adaptation. Accordingly, clinical isolates from chronically infected human lungs tend to hyperactivate this regulator enabling M. abscessus to escape macrophage killing.
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Affiliation(s)
- Juan M. Belardinelli
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, Colorado, USA
| | - Divya Arora
- Department of Medicine, Molecular Immunity Unit, University of Cambridge, MRC-Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Charlotte Avanzi
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, Colorado, USA
| | - William H. Wheat
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, Colorado, USA
| | - Josephine M. Bryant
- Department of Medicine, Molecular Immunity Unit, University of Cambridge, MRC-Laboratory of Molecular Biology, Cambridge, United Kingdom
- University of Cambridge Centre for AI in Medicine, Cambridge, United Kingdom
| | - John S. Spencer
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, Colorado, USA
| | - Tom L. Blundell
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Julian Parkhill
- Wellcome Sanger Institute, Hinxton, United Kingdom
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - R. Andres Floto
- Department of Medicine, Molecular Immunity Unit, University of Cambridge, MRC-Laboratory of Molecular Biology, Cambridge, United Kingdom
- University of Cambridge Centre for AI in Medicine, Cambridge, United Kingdom
- Cambridge Centre for Lung Infection, Papworth Hospital, Cambridge, United Kingdom
| | - Mary Jackson
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University, Fort Collins, Colorado, USA
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6
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Yang J, Zhang L, Qiao W, Luo Y. Mycobacterium tuberculosis: Pathogenesis and therapeutic targets. MedComm (Beijing) 2023; 4:e353. [PMID: 37674971 PMCID: PMC10477518 DOI: 10.1002/mco2.353] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 07/31/2023] [Accepted: 08/03/2023] [Indexed: 09/08/2023] Open
Abstract
Tuberculosis (TB) remains a significant public health concern in the 21st century, especially due to drug resistance, coinfection with diseases like immunodeficiency syndrome (AIDS) and coronavirus disease 2019, and the lengthy and costly treatment protocols. In this review, we summarize the pathogenesis of TB infection, therapeutic targets, and corresponding modulators, including first-line medications, current clinical trial drugs and molecules in preclinical assessment. Understanding the mechanisms of Mycobacterium tuberculosis (Mtb) infection and important biological targets can lead to innovative treatments. While most antitubercular agents target pathogen-related processes, host-directed therapy (HDT) modalities addressing immune defense, survival mechanisms, and immunopathology also hold promise. Mtb's adaptation to the human host involves manipulating host cellular mechanisms, and HDT aims to disrupt this manipulation to enhance treatment effectiveness. Our review provides valuable insights for future anti-TB drug development efforts.
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Affiliation(s)
- Jiaxing Yang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Laiying Zhang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Wenliang Qiao
- Department of Thoracic Surgery, West China HospitalSichuan UniversityChengduSichuanChina
- Lung Cancer Center, West China HospitalSichuan UniversityChengduSichuanChina
| | - Youfu Luo
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
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7
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Sau S, Roy A, Agnivesh PK, Kumar S, Guru SK, Sharma S, Kalia NP. Unravelling the flexibility of Mycobacterium tuberculosis: an escape way for the bacilli. J Med Microbiol 2023; 72. [PMID: 37261969 DOI: 10.1099/jmm.0.001695] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
The persistence of Mycobacterium tuberculosis makes it difficult to eradicate the associated infection from the host. The flexible nature of mycobacteria and their ability to adapt to adverse host conditions give rise to different drug-tolerant phenotypes. Granuloma formation restricts nutrient supply, limits oxygen availability and exposes bacteria to a low pH environment, resulting in non-replicating bacteria. These non-replicating mycobacteria, which need high doses and long exposure to anti-tubercular drugs, are the root cause of lengthy chemotherapy. Novel strategies, which are effective against non-replicating mycobacteria, need to be adopted to shorten tuberculosis treatment. This not only will reduce the treatment time but also will help prevent the emergence of multi-drug-resistant strains of mycobacteria.
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Affiliation(s)
- Shashikanta Sau
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Arnab Roy
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Puja Kumari Agnivesh
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Sunil Kumar
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Santosh Kumar Guru
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
| | - Sandeep Sharma
- Department of Medical Laboratory Sciences, Lovely Professional University, Phagwara, Punjab -144411, India
| | - Nitin Pal Kalia
- Department of Biological Sciences (Pharmacology and Toxicology), National Institute of Pharmaceutical Education and Research, Hyderabad, Telangana, India
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8
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Bo H, Moure UAE, Yang Y, Pan J, Li L, Wang M, Ke X, Cui H. Mycobacterium tuberculosis-macrophage interaction: Molecular updates. Front Cell Infect Microbiol 2023; 13:1062963. [PMID: 36936766 PMCID: PMC10020944 DOI: 10.3389/fcimb.2023.1062963] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of Tuberculosis (TB), remains a pathogen of great interest on a global scale. This airborne pathogen affects the lungs, where it interacts with macrophages. Acidic pH, oxidative and nitrosative stressors, and food restrictions make the macrophage's internal milieu unfriendly to foreign bodies. Mtb subverts the host immune system and causes infection due to its genetic arsenal and secreted effector proteins. In vivo and in vitro research have examined Mtb-host macrophage interaction. This interaction is a crucial stage in Mtb infection because lung macrophages are the first immune cells Mtb encounters in the host. This review summarizes Mtb effectors that interact with macrophages. It also examines how macrophages control and eliminate Mtb and how Mtb manipulates macrophage defense mechanisms for its own survival. Understanding these mechanisms is crucial for TB prevention, diagnosis, and treatment.
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Affiliation(s)
- Haotian Bo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ulrich Aymard Ekomi Moure
- The Ninth People's Hospital of Chongqing, Affiliated Hospital of Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Yuanmiao Yang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Jun Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Li Li
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Miao Wang
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Xiaoxue Ke
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
- *Correspondence: Hongjuan Cui, ; Xiaoxue Ke,
| | - Hongjuan Cui
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
- Jinfeng Laboratory, Chongqing, China
- *Correspondence: Hongjuan Cui, ; Xiaoxue Ke,
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9
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Iron–Sulfur Clusters toward Stresses: Implication for Understanding and Fighting Tuberculosis. INORGANICS 2022. [DOI: 10.3390/inorganics10100174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Tuberculosis (TB) remains the leading cause of death due to a single pathogen, accounting for 1.5 million deaths annually on the global level. Mycobacterium tuberculosis, the causative agent of TB, is persistently exposed to stresses such as reactive oxygen species (ROS), reactive nitrogen species (RNS), acidic conditions, starvation, and hypoxic conditions, all contributing toward inhibiting bacterial proliferation and survival. Iron–sulfur (Fe-S) clusters, which are among the most ancient protein prosthetic groups, are good targets for ROS and RNS, and are susceptible to Fe starvation. Mtb holds Fe-S containing proteins involved in essential biological process for Mtb. Fe-S cluster assembly is achieved via complex protein machineries. Many organisms contain several Fe-S assembly systems, while the SUF system is the only one in some pathogens such as Mtb. The essentiality of the SUF machinery and its functionality under the stress conditions encountered by Mtb underlines how it constitutes an attractive target for the development of novel anti-TB.
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10
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Parbhoo T, Mouton JM, Sampson SL. Phenotypic adaptation of Mycobacterium tuberculosis to host-associated stressors that induce persister formation. Front Cell Infect Microbiol 2022; 12:956607. [PMID: 36237425 PMCID: PMC9551238 DOI: 10.3389/fcimb.2022.956607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/24/2022] [Indexed: 11/29/2022] Open
Abstract
Mycobacterium tuberculosis exhibits a remarkable ability to interfere with the host antimicrobial response. The pathogen exploits elaborate strategies to cope with diverse host-induced stressors by modulating its metabolism and physiological state to prolong survival and promote persistence in host tissues. Elucidating the adaptive strategies that M. tuberculosis employs during infection to enhance persistence is crucial to understanding how varying physiological states may differentially drive disease progression for effective management of these populations. To improve our understanding of the phenotypic adaptation of M. tuberculosis, we review the adaptive strategies employed by M. tuberculosis to sense and coordinate a physiological response following exposure to various host-associated stressors. We further highlight the use of animal models that can be exploited to replicate and investigate different aspects of the human response to infection, to elucidate the impact of the host environment and bacterial adaptive strategies contributing to the recalcitrance of infection.
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11
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Molecular Connectivity between Extracytoplasmic Sigma Factors and PhoP Accounts for Coupled Mycobacterial Stress Response. J Bacteriol 2022; 204:e0011022. [PMID: 35608366 DOI: 10.1128/jb.00110-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis encounters numerous stress conditions within the host, but how it is able to mount a coupled stress response remains unknown. Growing evidence suggests that under acidic pH, M. tuberculosis modulates redox homeostasis. In an attempt to dissect the mechanistic details of responses to multiple stress conditions, here we studied the significance of connectivity of extracytoplasmic sigma factors with PhoP. We show that PhoP impacts the mycothiol redox state, and the H37Rv ΔphoP deletion mutant strain displays a significantly higher susceptibility to redox stress than the wild-type bacilli. To probe how the two regulators PhoP and redox-active sigma factor SigH contribute to redox homeostasis, we show that SigH controls expression of redox-active thioredoxin genes, a major mycobacterial antioxidant system, and under redox stress, SigH, but not PhoP, is recruited at the target promoters. Consistent with these results, interaction between PhoP and SigH fails to impact redox-dependent gene expression. This is in striking contrast to our previous results showing PhoP-dependent SigE recruitment within acid-inducible mycobacterial promoters to maintain pH homeostasis. Our subsequent results demonstrate reduced PhoP-SigH interaction in the presence of diamide and enhanced PhoP-SigE interaction under low pH. These contrasting results uncover the underlying mechanism of the mycobacterial adaptive program, coupling low pH with maintenance of redox homeostasis. IMPORTANCE M. tuberculosis encounters reductive stress under acidic pH. To investigate the mechanism of coupled stress response, we show that PhoP plays a major role in mycobacterial redox stress response. We observed a strong correlation of phoP-dependent redox-active expression of thioredoxin genes, a major mycobacterial antioxidant system. Further probing of functioning of regulators revealed that while PhoP controls pH homeostasis via its interaction with SigE, direct recruitment of SigH, but not PhoP-SigH interaction, controls expression of thioredoxin genes. These strikingly contrasting results showing enhanced PhoP-SigE interaction under acidic pH and reduced PhoP-SigH interaction under redox conditions uncover the underlying novel mechanism of the mycobacterial adaptive program, coupling low pH with maintenance of redox homeostasis.
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12
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Chung ES, Johnson WC, Aldridge BB. Types and functions of heterogeneity in mycobacteria. Nat Rev Microbiol 2022; 20:529-541. [PMID: 35365812 DOI: 10.1038/s41579-022-00721-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2022] [Indexed: 12/24/2022]
Abstract
The remarkable ability of Mycobacterium tuberculosis to survive attacks from the host immune response and drug treatment is due to the resilience of a few bacilli rather than a result of survival of the entire population. Maintenance of mycobacterial subpopulations with distinct phenotypic characteristics is key for survival in the face of dynamic and variable stressors encountered during infection. Mycobacterial populations develop a wide range of phenotypes through an innate asymmetric growth pattern and adaptation to fluctuating microenvironments during infection that point to heterogeneity being a vital survival strategy. In this Review, we describe different types of mycobacterial heterogeneity and discuss how heterogeneity is generated and regulated in response to environmental cues. We discuss how this heterogeneity may have a key role in recording memory of their environment at both the single-cell level and the population level to give mycobacterial populations plasticity to withstand complex stressors.
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Affiliation(s)
- Eun Seon Chung
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | - William C Johnson
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.,Tufts University School of Graduate Biomedical Sciences, Boston, MA, USA
| | - Bree B Aldridge
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA. .,Tufts University School of Graduate Biomedical Sciences, Boston, MA, USA. .,Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance, Tufts University, Boston, MA, USA. .,Department of Biomedical Engineering, Tufts University School of Engineering, Medford, MA, USA.
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13
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Wu X, Chauhan A, Layton AC, Lau Vetter MCY, Stackhouse BT, Williams DE, Whyte L, Pfiffner SM, Onstott TC, Vishnivetskaya TA. Comparative Metagenomics of the Active Layer and Permafrost from Low-Carbon Soil in the Canadian High Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:12683-12693. [PMID: 34472853 DOI: 10.1021/acs.est.1c00802] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Approximately 87% of the Arctic consists of low-organic carbon mineral soil, but knowledge of microbial activity in low-carbon permafrost (PF) and active layer soils remains limited. This study investigated the taxonomic composition and genetic potential of microbial communities at contrasting depths of the active layer (5, 35, and 65 cm below surface, bls) and PF (80 cm bls). We showed microbial communities in PF to be taxonomically and functionally different from those in the active layer. 16S rRNA gene sequence analysis revealed higher biodiversity in the active layer than in PF, and biodiversity decreased significantly with depth. The reconstructed 91 metagenome-assembled genomes showed that PF was dominated by heterotrophic, fermenting Bacteroidota using nitrite as their main electron acceptor. Prevalent microbes identified in the active layer belonged to bacterial taxa, gaining energy via aerobic respiration. Gene abundance in metagenomes revealed enrichment of genes encoding the plant-derived polysaccharide degradation and metabolism of nitrate and sulfate in PF, whereas genes encoding methane/ammonia oxidation, cold-shock protein, and two-component systems were generally more abundant in the active layer, particularly at 5 cm bls. The results of this study deepen our understanding of the low-carbon Arctic soil microbiome and improve prediction of the impacts of thawing PF.
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Affiliation(s)
- Xiaofen Wu
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Archana Chauhan
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Alice C Layton
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Maggie C Y Lau Vetter
- Department of Geosciences, Princeton University, Princeton, New Jersey 08544, United States
| | - Brandon T Stackhouse
- Department of Geosciences, Princeton University, Princeton, New Jersey 08544, United States
| | - Daniel E Williams
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Lyle Whyte
- Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada
| | - Susan M Pfiffner
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Tullis C Onstott
- Department of Geosciences, Princeton University, Princeton, New Jersey 08544, United States
| | - Tatiana A Vishnivetskaya
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee 37996, United States
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14
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Niño-Padilla EI, Velazquez C, Garibay-Escobar A. Mycobacterial biofilms as players in human infections: a review. BIOFOULING 2021; 37:410-432. [PMID: 34024206 DOI: 10.1080/08927014.2021.1925886] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 04/18/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
The role of biofilms in pathogenicity and treatment strategies is often neglected in mycobacterial infections. In recent years, the emergence of nontuberculous mycobacterial infections has necessitated the development of novel prophylactic strategies and elucidation of the mechanisms underlying the establishment of chronic infections. More importantly, the question arises whether members of the Mycobacterium tuberculosis complex can form biofilms and contribute to latent tuberculosis and drug resistance because of the long-lasting and recalcitrant nature of its infections. This review discusses some of the molecular mechanisms by which biofilms could play a role in infection or pathological events in humans.
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Affiliation(s)
| | - Carlos Velazquez
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora, México
| | - Adriana Garibay-Escobar
- Departamento de Ciencias Químico Biológicas, Universidad de Sonora, Hermosillo, Sonora, México
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15
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García EA, Blanco FC, Klepp LI, Pazos A, McNeil MR, Jackson M, Bigi F. Role of PhoPR in the response to stress of Mycobacterium bovis. Comp Immunol Microbiol Infect Dis 2020; 74:101593. [PMID: 33285386 DOI: 10.1016/j.cimid.2020.101593] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 11/28/2022]
Abstract
PhoP is part of the two-component PhoPR system that regulates the expression of virulence genes of Mycobacteria. The goal of this work was to elucidate the role of PhoP in the mechanism that Mycobacterium bovis, the causative agent of bovine tuberculosis, displays upon stress. An analysis of gene expression and acidic growth curves indicated that M. bovis neutralized the external acidic environment by inducing and secreting ammonia. We found that PhoP is essential for ammonia production/secretion and its role in this process seems to be the induction of asparaginase and urease expression. We also demonstrated that the lack of PhoP negatively affected the synthesis of phthiocerol dimycocerosates. This finding is consistent with the role of the lipid anabolism in maintaining the redox environment upon stress in mycobacteria. Altogether the results of this study indicate that PhoP plays an important role in the response mechanisms to stress of M. bovis.
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Affiliation(s)
- Elizabeth A García
- Instituto de Agrobiotecnología y Biología Molecular, (IABIMO) INTA-CONICET, Argentina; Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria Institute of Biotechnology, National Institute of Agricultural Technology, Argentina.
| | - Federico C Blanco
- Instituto de Agrobiotecnología y Biología Molecular, (IABIMO) INTA-CONICET, Argentina; Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria Institute of Biotechnology, National Institute of Agricultural Technology, Argentina.
| | - Laura I Klepp
- Instituto de Agrobiotecnología y Biología Molecular, (IABIMO) INTA-CONICET, Argentina; Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria Institute of Biotechnology, National Institute of Agricultural Technology, Argentina.
| | - Adriana Pazos
- Instituto Tecnología de Alimentos (ITA), INTA, Food Technology Institute, Argentina.
| | - Michael R McNeil
- Colorado State University, Dept. of Microbiology, Immunology and Pathology, USA.
| | - Mary Jackson
- Colorado State University, Dept. of Microbiology, Immunology and Pathology, USA.
| | - Fabiana Bigi
- Instituto de Agrobiotecnología y Biología Molecular, (IABIMO) INTA-CONICET, Argentina; Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria Institute of Biotechnology, National Institute of Agricultural Technology, Argentina.
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16
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Mahatha AC, Mal S, Majumder D, Saha S, Ghosh A, Basu J, Kundu M. RegX3 Activates whiB3 Under Acid Stress and Subverts Lysosomal Trafficking of Mycobacterium tuberculosis in a WhiB3-Dependent Manner. Front Microbiol 2020; 11:572433. [PMID: 33042081 PMCID: PMC7525159 DOI: 10.3389/fmicb.2020.572433] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/10/2020] [Indexed: 11/17/2022] Open
Abstract
Two-component systems (TCSs) are central to the ability of Mycobacterium tuberculosis to respond to stress. One such paired TCS is SenX3-RegX3, which responds to phosphate starvation. Here we show that RegX3 is required for M. tuberculosis to withstand low pH, one of the challenges encountered by the bacterium in the host environment, and that RegX3 activates the cytosolic redox sensor WhiB3 to launch an appropriate response to acid stress. We show that the whiB3 promoter of M. tuberculosis harbors a RegX3 binding motif. Electrophoretic mobility shift assays (EMSAs) show that phosphorylated RegX3 (RegX3-P) (but not its unphosphorylated counterpart) binds to this motif, whereas a DNA binding mutant, RegX3 (K204A) fails to do so. Mutation of the putative RegX3 binding motif on the whiB3 promoter, abrogates the binding of RegX3-P. The significance of this binding is established by demonstrating that the expression of whiB3 is significantly attenuated under phosphate starvation or under acid stress in the regX3-inactivated mutant, ΔregX3. Green fluorescent protein (GFP)-based reporter assays further confirm the requirement of RegX3 for the activation of the whiB3 promoter. The compromised survival of ΔregX3 under acid stress and its increased trafficking to the lysosomal compartment are reversed upon complementation with either regX3 or whiB3, suggesting that RegX3 exerts its effects in a WhiB3-dependent manner. Finally, using an in vitro granuloma model, we show that granuloma formation is compromised in the absence of regX3, but restored upon complementation with either regX3 or whiB3. Our findings provide insight into an important role of RegX3 in the network that regulates the survival of M. tuberculosis under acid stress similar to that encountered in its intracellular niche. Our results argue strongly in favor of a role of the RegX3-WhiB3 axis in establishment of M. tuberculosis infection.
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Affiliation(s)
| | - Soumya Mal
- Department of Chemistry, Bose Institute, Kolkata, India
| | | | - Sudipto Saha
- Division of Bioinformatics, Bose Institute, Kolkata, India
| | - Abhirupa Ghosh
- Division of Bioinformatics, Bose Institute, Kolkata, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, Kolkata, India
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17
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Potential therapeutic approaches for a sleeping pathogen: tuberculosis a case for bioinorganic chemistry. J Biol Inorg Chem 2020; 25:685-704. [PMID: 32676771 DOI: 10.1007/s00775-020-01803-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/30/2020] [Indexed: 12/18/2022]
Abstract
Mycobacterium tuberculosis (Mtb) has an old history as a human pathogen and still kills over one million people every year. One key feature of this bacterium is its dormancy: a phenomenon responsible for major changes in its metabolism and replication that have been associated with the need for a lengthy therapy for Mtb. This process is regulated by key heme-based sensors, particularly DosT and DevS (DosS), among other co-regulators, and also linked to nitrogen utilization (nitrate/nitrite) and stringent responses. In face of the current threat of tuberculosis, there is an urgent need to develop new therapeutic agents capable of targeting the dormant state, associated with the need for a lengthy therapy. Interestingly, many of those key proteins are indeed metallo-containing or metallo-dependent biomolecules, opening exciting bioinorganic opportunities. Here, we critically reviewed a series of small molecules targeting key proteins involved in these processes, including DosT/DevS/DevR, RegX3, MprA, MtrA, NarL, PknB, Rel, PPK, nitrate and nitrite reductases, GlnA1, aiming for new opportunities and alternative therapies. In the battle against Mycobacterium tuberculosis, new drug targets must be searched, in particular those involved in dormancy. A series of exciting cases for drug development involving metallo-containing or metallo-dependent biomolecules are reviewed, opening great opportunities for the bioinorganic chemistry community.
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18
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Multiplex Real-Time PCR-short TUB Assay for Detection of the Mycobacterium tuberculosis Complex in Smear-Negative Clinical Samples with Low Mycobacterial Loads. J Clin Microbiol 2019; 57:JCM.00733-19. [PMID: 31189585 DOI: 10.1128/jcm.00733-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/09/2019] [Indexed: 01/20/2023] Open
Abstract
Tuberculosis (TB) remains a major health problem worldwide. Control of TB requires rapid, accurate diagnosis of active disease. However, extrapulmonary TB is very difficult to diagnose because the clinical specimens have very low bacterial loads. Several molecular methods involving direct detection of the Mycobacterium tuberculosis complex (MTBC) have emerged in recent years. Real-time PCR amplification simultaneously combines the amplification and detection of candidate sequences by using fluorescent probes (mainly TaqMan or Molecular Beacons) in automated systems. The multiplex real-time PCR-short assay is performed using locked nucleic acid (LNA) probes (length, 8 to 9 nucleotides) in combination with CodUNG to detect multiple pathogens in clinical samples. In this study, we evaluated the performance of this novel multiplex assay for detecting the MTBC in comparison with that of the conventional culture-based method. The multiplex real-time PCR-shortTUB assay targets two genes, whiB3 (redox-responsive transcriptional regulator) and pstS1 (phosphate-specific transporter), yielding limits of detection (LOD) of 10 copies and 100 copies, respectively, and amplification efficiencies of 92% and 99.7%, respectively. A total of 94 extrapulmonary samples and pulmonary samples with low mycobacterial loads (all smear negative; 75 MTBC culture positive) were analyzed using the test, yielding an overall sensitivity of 88% and a specificity of 95%. For pleural fluid and tissues/biopsy specimens, the sensitivity was 83% and 85%, respectively. In summary, this technique could be implemented in routine clinical microbiology testing to reduce the overall turnaround time for MTBC detection and may therefore be a useful tool for the diagnosis of extrapulmonary tuberculosis and diagnosis using pulmonary samples with low mycobacterial loads.
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Baker JJ, Dechow SJ, Abramovitch RB. Acid Fasting: Modulation of Mycobacterium tuberculosis Metabolism at Acidic pH. Trends Microbiol 2019; 27:942-953. [PMID: 31324436 DOI: 10.1016/j.tim.2019.06.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/29/2019] [Accepted: 06/14/2019] [Indexed: 01/22/2023]
Abstract
Mycobacterium tuberculosis (Mtb) senses and adapts to acidic host environments during the course of pathogenesis. Mutants defective in acidic pH-dependent adaptations are often attenuated during macrophage or animal infections, supporting that these pathways are essential for pathogenesis and represent important new targets for drug discovery. This review examines a confluence of findings supporting that Mtb has restricted metabolism at acidic pH that results in the slowing of bacterial growth and changes in redox homeostasis. It is proposed that induction of the PhoPR regulon and anaplerotic metabolism, in concert with the restricted use of specific carbon sources, functions to counter reductive stress associated with acidic pH.
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Affiliation(s)
- Jacob J Baker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Shelby J Dechow
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Robert B Abramovitch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
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20
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Li X, Lv X, Lin Y, Zhen J, Ruan C, Duan W, Li Y, Xie J. Role of two-component regulatory systems in intracellular survival of Mycobacterium tuberculosis. J Cell Biochem 2019; 120:12197-12207. [PMID: 31026098 DOI: 10.1002/jcb.28792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 11/06/2022]
Abstract
The typical two-component regulatory systems (TCSs), consisting of response regulator and histidine kinase, play a central role in survival of pathogenic bacteria under stress conditions such as nutrient starvation, hypoxia, and nitrosative stress. A total of 11 complete paired two-component regulatory systems have been found in Mycobacterium tuberculosis, including a few isolated kinase and regulatory genes. Increasing evidence has shown that TCSs are closely associated with multiple physiological process like intracellular persistence, pathogenicity, and metabolism. This review gives the two-component signal transduction systems in M. tuberculosis and their signal transduction roles in adaption to the environment.
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Affiliation(s)
- Xue Li
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Xi Lv
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Yanping Lin
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Junfeng Zhen
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Cao Ruan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Wei Duan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Yue Li
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
| | - Jianping Xie
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences, Southwest University, Chongqing, China
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21
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Bush MJ. The actinobacterial WhiB-like (Wbl) family of transcription factors. Mol Microbiol 2018; 110:663-676. [PMID: 30179278 PMCID: PMC6282962 DOI: 10.1111/mmi.14117] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023]
Abstract
The WhiB‐like (Wbl) family of proteins are exclusively found in Actinobacteria. Wbls have been shown to play key roles in virulence and antibiotic resistance in Mycobacteria and Corynebacteria, reflecting their importance during infection by the human pathogens Mycobacterium tuberculosis, Mycobacterium leprae and Corynebacterium diphtheriae. In the antibiotic‐producing Streptomyces, several Wbls have important roles in the regulation of morphological differentiation, including WhiB, a protein that controls the initiation of sporulation septation and the founding member of the Wbl family. In recent years, genome sequencing has revealed the prevalence of Wbl paralogues in species throughout the Actinobacteria. Wbl proteins are small (generally ~80–140 residues) and each contains four invariant cysteine residues that bind an O2‐ and NO‐sensitive [4Fe–4S] cluster, raising the question as to how they can maintain distinct cellular functions within a given species. Despite their discovery over 25 years ago, the Wbl protein family has largely remained enigmatic. Here I summarise recent research in Mycobacteria, Corynebacteria and Streptomyces that sheds light on the biochemical function of Wbls as transcription factors and as potential sensors of O2 and NO. I suggest that Wbl evolution has created diversity in protein–protein interactions, [4Fe–4S] cluster‐sensitivity and the ability to bind DNA.
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Affiliation(s)
- Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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