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Luo G, Ming T, Yang L, He L, Tao T, Wang Y. Modulators targeting protein-protein interactions in Mycobacterium tuberculosis. Microbiol Res 2024; 284:127675. [PMID: 38636239 DOI: 10.1016/j.micres.2024.127675] [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: 09/27/2023] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 04/20/2024]
Abstract
Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis), mainly transmitted through droplets to infect the lungs, and seriously affecting patients' health and quality of life. Clinically, anti-TB drugs often entail side effects and lack efficacy against resistant strains. Thus, the exploration and development of novel targeted anti-TB medications are imperative. Currently, protein-protein interactions (PPIs) offer novel avenues for anti-TB drug development, and the study of targeted modulators of PPIs in M. tuberculosis has become a prominent research focus. Furthermore, a comprehensive PPI network has been constructed using computational methods and bioinformatics tools. This network allows for a more in-depth analysis of the structural biology of PPIs and furnishes essential insights for the development of targeted small-molecule modulators. Furthermore, this article provides a detailed overview of the research progress and regulatory mechanisms of PPI modulators in M. tuberculosis, the causative agent of TB. Additionally, it summarizes potential targets for anti-TB drugs and discusses the prospects of existing PPI modulators.
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Affiliation(s)
- Guofeng Luo
- School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Tianqi Ming
- State Key Laboratory of Southwestern Chinese Medicine Resources, Department of Pharmacology, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Luchuan Yang
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China
| | - Lei He
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China
| | - Tao Tao
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China
| | - Yanmei Wang
- Institute of traditional Chinese medicine, Sichuan College of traditional Chinese Medicine (Sichuan Second Hospital of TCM), Chengdu 610031, China.
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2
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Oh Y, Oh JI. The RsfSR two-component system regulates SigF function by monitoring the state of the respiratory electron transport chain in Mycobacterium smegmatis. J Biol Chem 2024; 300:105764. [PMID: 38367670 PMCID: PMC10950880 DOI: 10.1016/j.jbc.2024.105764] [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: 12/14/2023] [Revised: 02/02/2024] [Accepted: 02/12/2024] [Indexed: 02/19/2024] Open
Abstract
In Mycobacterium smegmatis, the transcriptional activity of the alternative sigma factor SigF is posttranslationally regulated by the partner switching system consisting of SigF, the anti-SigF RsbW1, and three anti-SigF antagonists (RsfA, RsfB, and RsbW3). We previously demonstrated that expression of the SigF regulon is strongly induced in the Δaa3 mutant of M. smegmatis lacking the aa3 cytochrome c oxidase, the major terminal oxidase in the respiratory electron transport chain. Here, we identified and characterized the RsfSR two-component system involved in regulating the phosphorylation state of the major anti-SigF antagonist RsfB. RsfS (MSMEG_6130) is a histidine kinase with the cyclase/histidine kinase-associated sensing extracellular 3 domain at its N terminus, and RsfR (MSMEG_6131) is a receiver domain-containing protein phosphatase 2C-type phosphatase that can dephosphorylate phosphorylated RsfB. We demonstrated that phosphorylation of RsfR on Asp74 by RsfS reduces the phosphatase activity of RsfR toward phosphorylated RsfB and that the cellular abundance of the active unphosphorylated RsfB is increased in the Δaa3 mutant relative to the WT strain. We also demonstrated that the RsfSR two-component system is required for induction of the SigF regulon under respiration-inhibitory conditions such as inactivation of the cytochrome bcc1 complex and aa3 cytochrome c oxidase, as well as hypoxia, electron donor-limiting, high ionic strength, and low pH conditions. Collectively, our results reveal a key regulatory element involved in regulating the SigF signaling system by monitoring the state of the respiratory electron transport chain.
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Affiliation(s)
- Yuna Oh
- Department of Integrated Biological Science, Pusan National University, Busan, Korea
| | - Jeong-Il Oh
- Department of Integrated Biological Science, Pusan National University, Busan, Korea; Microbiological Resource Research Institute, Pusan National University, Busan, Korea.
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3
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Orgeur M, Sous C, Madacki J, Brosch R. Evolution and emergence of Mycobacterium tuberculosis. FEMS Microbiol Rev 2024; 48:fuae006. [PMID: 38365982 PMCID: PMC10906988 DOI: 10.1093/femsre/fuae006] [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: 11/09/2023] [Revised: 01/12/2024] [Accepted: 02/13/2024] [Indexed: 02/18/2024] Open
Abstract
Tuberculosis (TB) remains one of the deadliest infectious diseases in human history, prevailing even in the 21st century. The causative agents of TB are represented by a group of closely related bacteria belonging to the Mycobacterium tuberculosis complex (MTBC), which can be subdivided into several lineages of human- and animal-adapted strains, thought to have shared a last common ancestor emerged by clonal expansion from a pool of recombinogenic Mycobacterium canettii-like tubercle bacilli. A better understanding of how MTBC populations evolved from less virulent mycobacteria may allow for discovering improved TB control strategies and future epidemiologic trends. In this review, we highlight new insights into the evolution of mycobacteria at the genus level, describing different milestones in the evolution of mycobacteria, with a focus on the genomic events that have likely enabled the emergence and the dominance of the MTBC. We also review the recent literature describing the various MTBC lineages and highlight their particularities and differences with a focus on host preferences and geographic distribution. Finally, we discuss on putative mechanisms driving the evolution of tubercle bacilli and mycobacteria in general, by taking the mycobacteria-specific distributive conjugal transfer as an example.
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Affiliation(s)
- Mickael Orgeur
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
| | - Camille Sous
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
| | - Jan Madacki
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR 2000, Unit for Human Evolutionary Genetics, 75015 Paris, France
| | - Roland Brosch
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Unit for Integrated Mycobacterial Pathogenomics, 75015 Paris, France
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4
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Dawrs SN, Virdi R, Islam MN, Hasan NA, Norton GJ, Crooks JL, Parr J, Heinz D, Cool CD, Belisle JT, Chan ED, Honda JR. Immunological and metabolic characterization of environmental Mycobacterium chimaera infection in a murine model. Microbes Infect 2023; 25:105184. [PMID: 37453489 DOI: 10.1016/j.micinf.2023.105184] [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: 11/21/2022] [Revised: 06/22/2023] [Accepted: 07/07/2023] [Indexed: 07/18/2023]
Abstract
Mycobacterium chimaera causes pulmonary disease, but little is known of gradations in isolate virulence. Previously, 17 M. chimaera isolates were screened for survival in THP1 macrophages. "M. chimaera 1" was categorized as "more virulent" because it showed the greatest survival in macrophages, whereas "M. chimaera 2" was categorized as "less virulent" with reduced survival. Herein, we infected C3HeB/FeJ mice to compare the in vivo immune responses to M. chimaera 1 and 2. Unlike macrophages, significantly lower M. chimaera 1 counts were recovered from mouse lung tissue and BAL cells with less lung histopathologic changes compared to M. chimaera 2. Compared to M. chimaera 2, significantly more IL-1β, IL-6, and TNFα was produced early after M. chimaera 1 infection. LC-MS metabolomics analyses of BAL fluid revealed divergence in sphingolipid, phospholipid metabolism between M. chimaera 1 versus M. chimaera 2 mice. From pan-GWAS analyses, virulence and organizing DNA/molecular structure genes were associated with more virulent M. chimaera isolates. Vigorous lung-specific immune responses to M. chimaera 1 may influence effective bacterial control, but for a different isolate M. chimaera 2, subvert immune control. Continued studies of the gradations in virulence among the same NTM species will advance our understanding of NTM pathogenesis.
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Affiliation(s)
- Stephanie N Dawrs
- Center for Genes, Environment, and Health, National Jewish Health, CO, United States.
| | - Ravleen Virdi
- Center for Genes, Environment, and Health, National Jewish Health, CO, United States.
| | - M Nurul Islam
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Nabeeh A Hasan
- Center for Genes, Environment, and Health, National Jewish Health, CO, United States
| | - Grant J Norton
- Center for Genes, Environment, and Health, National Jewish Health, CO, United States.
| | - James L Crooks
- Division of Biostatistics and Bioinformatics, National Jewish Health, Colorado, United States; Department of Biostatistics and Informatics, Colorado School of Public Health, Aurora, CO, United States
| | - Jane Parr
- Division of Pathology and Department of Medicine, National Jewish Health, CO, United States
| | - David Heinz
- Division of Pathology and Department of Medicine, National Jewish Health, CO, United States
| | - Carlyne D Cool
- Division of Pathology and Department of Medicine, National Jewish Health, CO, United States; Department of Pathology, University of Colorado Anschutz Medical Campus, CO, United States
| | - John T Belisle
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Edward D Chan
- Department of Medicine and Academic Affairs, National Jewish Health, Denver, CO, United States; Division of Pulmonary Science and Critical Care Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, United States; Department of Medicine, Rocky Mountain Regional Veterans Affairs Medical Center, Denver, CO, United States
| | - Jennifer R Honda
- Department of Cellular and Molecular Biology, School of Medicine, University of Texas Health Science Center at Tyler, TX, United States.
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5
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Oh Y, Lee HN, Ko EM, Jeong JA, Park SW, Oh JI. Mycobacterial Regulatory Systems Involved in the Regulation of Gene Expression Under Respiration-Inhibitory Conditions. J Microbiol 2023; 61:297-315. [PMID: 36847970 DOI: 10.1007/s12275-023-00026-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 03/01/2023]
Abstract
Mycobacterium tuberculosis is the causative agent of tuberculosis. M. tuberculosis can survive in a dormant state within the granuloma, avoiding the host-mounting immune attack. M. tuberculosis bacilli in this state show increased tolerance to antibiotics and stress conditions, and thus the transition of M. tuberculosis to the nonreplicating dormant state acts as an obstacle to tuberculosis treatment. M. tuberculosis in the granuloma encounters hostile environments such as hypoxia, nitric oxide, reactive oxygen species, low pH, and nutrient deprivation, etc., which are expected to inhibit respiration of M. tuberculosis. To adapt to and survive in respiration-inhibitory conditions, it is required for M. tuberculosis to reprogram its metabolism and physiology. In order to get clues to the mechanism underlying the entry of M. tuberculosis to the dormant state, it is important to understand the mycobacterial regulatory systems that are involved in the regulation of gene expression in response to respiration inhibition. In this review, we briefly summarize the information regarding the regulatory systems implicated in upregulation of gene expression in mycobacteria exposed to respiration-inhibitory conditions. The regulatory systems covered in this review encompass the DosSR (DevSR) two-component system, SigF partner switching system, MprBA-SigE-SigB signaling pathway, cAMP receptor protein, and stringent response.
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Affiliation(s)
- Yuna Oh
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Ha-Na Lee
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Eon-Min Ko
- Division of Bacterial Disease Research, Center for Infectious Disease Research, Korea Disease Control and Prevention Agency, National Institute of Infectious Diseases, National Institute of Health, Osong, 28159, Republic of Korea
| | - Ji-A Jeong
- Division of Bacterial Disease Research, Center for Infectious Disease Research, Korea Disease Control and Prevention Agency, National Institute of Infectious Diseases, National Institute of Health, Osong, 28159, Republic of Korea
| | - Sae Woong Park
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Jeong-Il Oh
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea. .,Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea.
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6
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Potential Use of Mycobacterium paragordonae for Antimycobacterial Drug Screening Systems. J Microbiol 2023; 61:121-129. [PMID: 36719620 DOI: 10.1007/s12275-022-00009-1] [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: 06/23/2022] [Revised: 10/20/2022] [Accepted: 11/25/2022] [Indexed: 02/01/2023]
Abstract
Our recent genome-based study indicated that Mycobacterium paragordonae (Mpg) has evolved to become more adapted to an intracellular lifestyle within free-living environmental amoeba and its enhanced intracellular survival within Acanthamoeba castellanii was also proved. Here, we sought to investigate potential use of Mpg for antimycobacterial drug screening systems. Our data showed that Mpg is more susceptible to various antibiotics compared to the close species M. marinum (Mmar) and M. gordonae, further supporting its intracellular lifestyle in environments, which would explain its protection from environmental insults. In addition, we developed two bacterial whole-cell-based drug screening systems using a recombinant Mpg stain harboring a luciferase reporter vector (rMpg-LuxG13): one for direct application to rMpg-LuxG13 and the other for drug screening via the interaction of rMpg-LuxG13 with A. castellanii. Direct application to rMpg-LuxG13 showed lower inhibitory concentration 50 (IC50) values of rifampin, isoniazid, clarithromycin, and ciprofloxacin against Mpg compared to Mmar. Application of drug screening system via the interaction of rMpg-LuxG13 with A. castellanii also exhibited lower IC50 values for rifampin against Mpg compared to Mmar. In conclusion, our data indicate that Mpg is more susceptible to various antibiotics than other strains. In addition, our data also demonstrate the feasibility of two whole cell-based drug screening systems using rMpg-LuxG13 strain for the discovery of novel anti-mycobacterial drugs.
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7
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Hadi SA, Brenner EP, Palmer MV, Waters WR, Thacker TC, Vilchèze C, Larsen MH, Jacobs WR, Sreevatsan S. Mycobacterium bovis Strain Ravenel Is Attenuated in Cattle. Pathogens 2022; 11:1330. [PMID: 36422582 PMCID: PMC9699013 DOI: 10.3390/pathogens11111330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/19/2022] [Accepted: 11/08/2022] [Indexed: 08/02/2023] Open
Abstract
Mycobacterium tuberculosis variant bovis (MBO) has one of the widest known mammalian host ranges, including humans. Despite the characterization of this pathogen in the 1800s and whole genome sequencing of a UK strain (AF2122) nearly two decades ago, the basis of its host specificity and pathogenicity remains poorly understood. Recent experimental calf infection studies show that MBO strain Ravenel (MBO Ravenel) is attenuated in the cattle host compared to other pathogenic strains of MBO. In the present study, experimental infections were performed to define attenuation. Whole genome sequencing was completed to identify regions of differences (RD) and single nucleotide polymorphisms (SNPs) to explain the observed attenuation. Comparative genomic analysis of MBO Ravenel against three pathogenic strains of MBO (strains AF2122-97, 10-7428, and 95-1315) was performed. Experimental infection studies on five calves each, with either MBO Ravenel or 95-1315, revealed no visible lesions in all five animals in the Ravenel group despite robust IFN-γ responses. Out of 486 polymorphisms in the present analysis, 173 were unique to MBO Ravenel among the strains compared. A high-confidence subset of nine unique SNPs were missense mutations in genes with annotated functions impacting two major MBO survival and virulence pathways: (1) Cell wall synthesis & transport [espH (A103T), mmpL8 (V888I), aftB (H484Y), eccC5 (T507M), rpfB (E263G)], and (2) Lipid metabolism & respiration [mycP1(T125I), pks5 (G455S), fadD29 (N231S), fadE29 (V360G)]. These substitutions likely contribute to the observed attenuation. Results from experimental calf infections and the functional attributions of polymorphic loci on the genome of MBO Ravenel provide new insights into the strain's genotype-disease phenotype associations.
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Affiliation(s)
- Syeda A. Hadi
- Pathobiology and Diagnostic Investigation Department, Michigan State University, East Lansing, MI 48824, USA
| | - Evan P. Brenner
- Pathobiology and Diagnostic Investigation Department, Michigan State University, East Lansing, MI 48824, USA
| | - Mitchell V. Palmer
- National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, Ames, IA 50010, USA
| | - W. Ray Waters
- National Animal Disease Center, Agricultural Research Service, US Department of Agriculture, Ames, IA 50010, USA
| | - Tyler C. Thacker
- National Veterinary Services Laboratories, US Department of Agriculture, Ames, IA 50010, USA
| | - Catherine Vilchèze
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10475, USA
| | - Michelle H. Larsen
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10475, USA
| | - William R. Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10475, USA
| | - Srinand Sreevatsan
- Pathobiology and Diagnostic Investigation Department, Michigan State University, East Lansing, MI 48824, USA
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8
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Secretory proteins of
Mycobacterium tuberculosis
and their roles in modulation of host immune responses: focus on therapeutic targets. FEBS J 2022; 289:4146-4171. [DOI: 10.1111/febs.16369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/04/2022] [Accepted: 01/21/2022] [Indexed: 12/01/2022]
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9
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Guo Q, Bi J, Lin Q, Ye T, Wang Z, Wang Z, Liu L, Zhang G. Whole Genome Sequencing Identifies Novel Mutations Associated With Bedaquiline Resistance in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:807095. [PMID: 35694543 PMCID: PMC9184757 DOI: 10.3389/fcimb.2022.807095] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/26/2022] [Indexed: 11/18/2022] Open
Abstract
Bedaquiline (BDQ), a new antitubercular agent, has been used to treat drug-resistant tuberculosis (TB). Although mutations in atpE, rv0678, and pepQ confer major resistance to BDQ, the mechanisms of resistance to BDQ in vitro and in clinical settings have not been fully elucidated. We selected BDQ-resistant mutants from 7H10 agar plates containing 0.5 mg/L BDQ (the critical concentration) and identified mutations associated with BDQ resistance through whole genome sequencing and Sanger sequencing. A total of 1,025 mutants were resistant to BDQ. We randomly selected 168 mutants for further analysis and discovered that 157/168 BDQ-resistant mutants harbored mutations in rv0678, which encodes a transcriptional regulator that represses the expression of the efflux pump, MmpS5–MmpL5. Moreover, we found two mutations with high frequency in rv0678 at nucleotide positions 286–287 (CG286–287 insertion; accounting for 26.8% [45/168]) and 198–199 (G198, G199 insertion, and G198 deletion; accounting for 14.3% [24/168]). The other mutations were dispersed covering the entire rv0678 gene. Moreover, we found that one new gene, glpK, harbors a G572 insertion; this mutation has a high prevalence (85.7%; 144/168) in the isolated mutants, and the minimum inhibitory concentration (MIC) assay demonstrated that it is closely associated with BDQ resistance. In summary, we characterized 168/1,025 mutants resistant to BDQ and found that mutations in rv0678 confer the primary mechanism of BDQ resistance. Moreover, we identified a new gene (glpK) involved in BDQ resistance. Our study offers new insights and valuable information that will contribute to rapid identification of BDQ-resistant isolates in clinical settings.
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Affiliation(s)
- Qinglong Guo
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Jing Bi
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Qiao Lin
- Department of Traditional Chinese Medicine, The Baoan People’s Hospital of Shenzhen, Shenzhen University, Shenzhen, China
| | - Taosheng Ye
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Zhongyuan Wang
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Zhaoqin Wang
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Lei Liu
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Guoliang Zhang
- National Clinical Research Center for Infectious Diseases, Guangdong Provincial Clinical Research Center for Tuberculosis, Shenzhen Third People’s Hospital, Southern University of Science and Technology, Shenzhen, China
- *Correspondence: Guoliang Zhang,
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Multiple genetic paths including massive gene amplification allow Mycobacterium tuberculosis to overcome loss of ESX-3 secretion system substrates. Proc Natl Acad Sci U S A 2022; 119:2112608119. [PMID: 35193958 PMCID: PMC8872769 DOI: 10.1073/pnas.2112608119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2021] [Indexed: 01/18/2023] Open
Abstract
The Mycobacterium tuberculosis (Mtb) ESX-3 type VII secretion system plays a critical role in iron acquisition. Infection of mice with highly attenuated Mtb deletion mutants lacking esxG or esxH, genes encoding key ESX-3 substrates, unexpectedly yielded suppressor mutants with restored capacity to grow in vivo and in vitro in the absence of iron supplementation. Whole-genome sequencing identified two mechanisms of suppression, the disruption of a transcriptional repressor that regulates expression of an ESX-3 paralogous region encoding EsxR and EsxS, and a massive 38- to 60-fold gene amplification of this same region. These data are significant because they reveal a previously unrecognized iron acquisition regulon and inform mechanisms of Mtb chromosome evolution. Mycobacterium tuberculosis (Mtb) possesses five type VII secretion systems (T7SS), virulence determinants that include the secretion apparatus and associated secretion substrates. Mtb strains deleted for the genes encoding substrates of the ESX-3 T7SS, esxG or esxH, require iron supplementation for in vitro growth and are highly attenuated in vivo. In a subset of infected mice, suppressor mutants of esxG or esxH deletions were isolated, which enabled growth to high titers or restored virulence. Suppression was conferred by mechanisms that cause overexpression of an ESX-3 paralogous region that lacks genes for the secretion apparatus but encodes EsxR and EsxS, apparent ESX-3 orphan substrates that functionally compensate for the lack of EsxG or EsxH. The mechanisms include the disruption of a transcriptional repressor and a massive 38- to 60-fold gene amplification. These data identify an iron acquisition regulon, provide insight into T7SS, and reveal a mechanism of Mtb chromosome evolution involving “accordion-type” amplification.
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11
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Shyam M, Verma H, Bhattacharje G, Mukherjee P, Singh S, Kamilya S, Jalani P, Das S, Dasgupta A, Mondal A, Das AK, Singh A, Brucoli F, Bagnéris C, Dickman R, Basavanakatti VN, Naresh Babu P, Sankaran V, Dev A, Sinha BN, Bhakta S, Jayaprakash V. Mycobactin Analogues with Excellent Pharmacokinetic Profile Demonstrate Potent Antitubercular Specific Activity and Exceptional Efflux Pump Inhibition. J Med Chem 2022; 65:234-256. [PMID: 34981940 DOI: 10.1021/acs.jmedchem.1c01349] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we have designed and synthesized pyrazoline analogues that partially mimic the structure of mycobactin, to address the requirement of novel therapeutics to tackle the emerging global challenge of antimicrobial resistance (AMR). Our investigation resulted in the identification of novel lead compounds 44 and 49 as potential mycobactin biosynthesis inhibitors against mycobacteria. Moreover, candidates efficiently eradicated intracellularly surviving mycobacteria. Thermofluorimetric analysis and molecular dynamics simulations suggested that compounds 44 and 49 bind to salicyl-AMP ligase (MbtA), a key enzyme in the mycobactin biosynthetic pathway. To the best of our knowledge, these are the first rationally designed mycobactin inhibitors to demonstrate an excellent in vivo pharmacokinetic profile. In addition, these compounds also exhibited more potent whole-cell efflux pump inhibition than known efflux pump inhibitors verapamil and chlorpromazine. Results from this study pave the way for the development of 3-(2-hydroxyphenyl)-5-(aryl)-pyrazolines as a new weapon against superbug-associated AMR challenges.
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Affiliation(s)
- Mousumi Shyam
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India.,Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Harshita Verma
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Gourab Bhattacharje
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | | | | | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, CV Raman Avenue, Bangalore 560012, India
| | - Pushpendu Jalani
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10 Janakipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Swetarka Das
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10 Janakipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Arunava Dasgupta
- Microbiology Division, CSIR-Central Drug Research Institute, Sector 10 Janakipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, CV Raman Avenue, Bangalore 560012, India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | | | - Federico Brucoli
- Leicester School of Pharmacy, De Montfort University, The Gateway, Leicester LE1 9BH, U.K
| | - Claire Bagnéris
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Rachael Dickman
- Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, University of London, London WC1N 1AX, U.K
| | | | | | - Vadivelan Sankaran
- Eurofins Advinus Limited, 21 & 22, Peenya Industrial area, Bengaluru 560058, India
| | - Abhimanyu Dev
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India
| | - Barij Nayan Sinha
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of London, Malet Street, London WC1E 7HX, U.K
| | - Venkatesan Jayaprakash
- Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi 835215, Jharkhand, India
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12
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Spencer BL, Tak U, Mendonça JC, Nagao PE, Niederweis M, Doran KS. A type VII secretion system in Group B Streptococcus mediates cytotoxicity and virulence. PLoS Pathog 2021; 17:e1010121. [PMID: 34871327 PMCID: PMC8675928 DOI: 10.1371/journal.ppat.1010121] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/16/2021] [Accepted: 11/16/2021] [Indexed: 12/20/2022] Open
Abstract
Type VII secretion systems (T7SS) have been identified in Actinobacteria and Firmicutes and have been shown to secrete effector proteins with functions in virulence, host toxicity, and/or interbacterial killing in a few genera. Bioinformatic analysis indicates that isolates of Group B Streptococcus (GBS) encode at least four distinct subtypes of T7SS machinery, three of which encode adjacent putative T7SS effectors with WXG and LXG motifs. However, the function of T7SS in GBS pathogenesis is unknown. Here we assessed the role of the most abundant GBS T7SS subtype during GBS pathogenesis. In a murine model of hematogenous meningitis, mice infected with GBS lacking a functional T7SS or lacking the secreted WXG100 effector EsxA exhibited less mortality, lower bacterial burdens in tissues, and decreased inflammation in the brain compared to mice infected with the parental GBS strain. We further showed that this T7SS induces cytotoxicity in brain endothelium and that EsxA contributes to these cytotoxicity phenotypes in a WXG motif-dependent manner. Finally, we determined that EsxA is a pore-forming protein, thus demonstrating the first role for a non-mycobacterial EsxA homolog in pore formation. This work reveals the importance of a T7SS in host–GBS interactions and has implications for T7SS effector function in other Gram-positive bacteria. Group B Streptococcus (GBS) is an important human pathogen that is a leading cause of invasive disease in newborns and certain adult populations, including pregnant women, the elderly, and those with diabetes. During pregnancy, asymptomatically colonizing GBS in the female genital tract can be transmitted to the fetus or newborn and can result in neonatal meningitis upon GBS disruption of the blood-brain barrier (BBB). GBS encodes a type VII secretion system (T7SS), which may allow export of proteins and/or toxins that promote BBB disruption; however, the GBS T7SS has not been studied. Here we show that GBS encodes four types of T7SSs and that the most prevalent subtype is important for GBS meningitis progression, possibly by inducing inflammation and cell death in the brain. We also show that a secreted T7SS effector protein, EsxA, contributes to GBS pathogenesis and can form pores in lipid membranes. This is the first demonstration of EsxA-mediated pore-formation in Gram-positive bacteria.
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Affiliation(s)
- Brady L. Spencer
- University of Colorado Anschutz Medical Campus, Department of Immunology and Microbiology, Aurora, Colorado, United States of America
| | - Uday Tak
- University of Alabama at Birmingham, Department of Microbiology, Birmingham, Alabama, United States of America
| | - Jéssica C. Mendonça
- University of Colorado Anschutz Medical Campus, Department of Immunology and Microbiology, Aurora, Colorado, United States of America
- Rio de Janeiro State University, Roberto Alcântara Gomes Biology Institute, Rio de Janeiro, RJ, Brazil
| | - Prescilla E. Nagao
- Rio de Janeiro State University, Roberto Alcântara Gomes Biology Institute, Rio de Janeiro, RJ, Brazil
| | - Michael Niederweis
- University of Alabama at Birmingham, Department of Microbiology, Birmingham, Alabama, United States of America
| | - Kelly S. Doran
- University of Colorado Anschutz Medical Campus, Department of Immunology and Microbiology, Aurora, Colorado, United States of America
- * E-mail:
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13
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Rivera-Calzada A, Famelis N, Llorca O, Geibel S. Type VII secretion systems: structure, functions and transport models. Nat Rev Microbiol 2021; 19:567-584. [PMID: 34040228 DOI: 10.1038/s41579-021-00560-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2021] [Indexed: 02/07/2023]
Abstract
Type VII secretion systems (T7SSs) have a key role in the secretion of effector proteins in non-pathogenic mycobacteria and pathogenic mycobacteria such as Mycobacterium tuberculosis, the main causative agent of tuberculosis. Tuberculosis-causing mycobacteria, still accounting for 1.4 million deaths annually, rely on paralogous T7SSs to survive in the host and efficiently evade its immune response. Although it is still unknown how effector proteins of T7SSs cross the outer membrane of the diderm mycobacterial cell envelope, recent advances in the structural characterization of these secretion systems have revealed the intricate network of interactions of conserved components in the plasma membrane. This structural information, added to recent advances in the molecular biology and regulation of mycobacterial T7SSs as well as progress in our understanding of their secreted effector proteins, is shedding light on the inner working of the T7SS machinery. In this Review, we highlight the implications of these studies and the derived transport models, which provide new scenarios for targeting the deathly human pathogen M. tuberculosis.
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Affiliation(s)
- Angel Rivera-Calzada
- Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
| | - Nikolaos Famelis
- Institute for Molecular Infection Biology, Julius-Maximilian University of Würzburg, Würzburg, Germany.,Rudolf Virchow Center for Integrative and Translational Biomedicine, Julius-Maximilian University of Würzburg, Würzburg, Germany
| | - Oscar Llorca
- Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Sebastian Geibel
- Institute for Molecular Infection Biology, Julius-Maximilian University of Würzburg, Würzburg, Germany. .,Rudolf Virchow Center for Integrative and Translational Biomedicine, Julius-Maximilian University of Würzburg, Würzburg, Germany.
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14
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Kamal SM, Simpson DJ, Wang Z, Gänzle M, Römling U. Horizontal Transmission of Stress Resistance Genes Shape the Ecology of Beta- and Gamma-Proteobacteria. Front Microbiol 2021; 12:696522. [PMID: 34295324 PMCID: PMC8290217 DOI: 10.3389/fmicb.2021.696522] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/07/2021] [Indexed: 01/25/2023] Open
Abstract
The transmissible locus of stress tolerance (tLST) is found mainly in beta- and gamma-Proteobacteria and confers tolerance to elevated temperature, pressure, and chlorine. This genomic island, previously referred to as transmissible locus of protein quality control or locus of heat resistance likely originates from an environmental bacterium thriving in extreme habitats, but has been widely transmitted by lateral gene transfer. Although highly conserved, the gene content on the island is subject to evolution and gene products such as small heat shock proteins are present in several functionally distinct sequence variants. A number of these genes are xenologs of core genome genes with the gene products to widen the substrate spectrum and to be highly (complementary) expressed thus their functionality to become dominant over core genome genes. In this review, we will present current knowledge of the function of core tLST genes and discuss current knowledge on selection and counter-selection processes that favor maintenance of the tLST island, with frequent acquisition of gene products involved in cyclic di-GMP signaling, in different habitats from the environment to animals and plants, processed animal and plant products, man-made environments, and subsequently humans.
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Affiliation(s)
- Shady Mansour Kamal
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - David J Simpson
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Zhiying Wang
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
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15
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A multi-targeting pre-clinical candidate against drug-resistant tuberculosis. Tuberculosis (Edinb) 2021; 129:102104. [PMID: 34214859 DOI: 10.1016/j.tube.2021.102104] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/11/2021] [Accepted: 06/13/2021] [Indexed: 11/20/2022]
Abstract
FNDR-20081 [4-{4-[5-(4-Isopropyl-phenyl)- [1,2,4]oxadiazol-3-ylmethyl]-piperazin-1-yl}-7-pyridin-3-yl-quinoline] is a novel, first in class anti-tubercular pre-clinical candidate against sensitive and drug-resistant Mycobacterium tuberculosis (Mtb). In-vitro combination studies of FNDR-20081 with first- and second-line drugs exhibited no antagonism, suggesting its compatibility for developing new combination-regimens. FNDR-20081, which is non-toxic with no CYP3A4 liability, demonstrated exposure-dependent killing of replicating-Mtb, as well as the non-replicating-Mtb, and efficacy in a mouse model of infection. Whole genome sequencing (WGS) of FNDR-20081 resistant mutants revealed the identification of pleotropic targets: marR (Rv0678), a regulator of MmpL5, a transporter/efflux pump mechanism for drug resistance; and Rv3683, a putative metalloprotease potentially involved in peptidoglycan biosynthesis. In summary, FNDR-20081 is a promising first in class compound with the potential to form a new combination regimen for MDR-TB treatment.
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16
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Madacki J, Kopál M, Jackson M, Korduláková J. Mycobacterial Epoxide Hydrolase EphD Is Inhibited by Urea and Thiourea Derivatives. Int J Mol Sci 2021; 22:2884. [PMID: 33809178 PMCID: PMC7998700 DOI: 10.3390/ijms22062884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/01/2021] [Accepted: 03/10/2021] [Indexed: 11/16/2022] Open
Abstract
The genome of the human intracellular pathogen Mycobacterium tuberculosis encodes an unusually large number of epoxide hydrolases, which are thought to be involved in lipid metabolism and detoxification reactions needed to endure the hostile environment of host macrophages. These enzymes therefore represent suitable targets for compounds such as urea derivatives, which are known inhibitors of soluble epoxide hydrolases. In this work, we studied in vitro the effect of the thiourea drug isoxyl on six epoxide hydrolases of M. tuberculosis using a fatty acid substrate. We show that one of the proteins inhibited by isoxyl is EphD, an enzyme involved in the metabolism of mycolic acids, key components of the mycobacterial cell wall. By analyzing mycolic acid profiles, we demonstrate the inhibition of EphD epoxide hydrolase activity by isoxyl and two other urea-based inhibitors, thiacetazone and AU1235, inside the mycobacterial cell.
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Affiliation(s)
- Jan Madacki
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia; (J.M.); (M.K.)
| | - Martin Kopál
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia; (J.M.); (M.K.)
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA;
| | - Jana Korduláková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia; (J.M.); (M.K.)
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17
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Molecular Cloning, Purification and Characterization of Mce1R of Mycobacterium tuberculosis. Mol Biotechnol 2021; 63:200-220. [PMID: 33423211 DOI: 10.1007/s12033-020-00293-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2020] [Indexed: 10/22/2022]
Abstract
The mce1 operon of Mycobacterium tuberculosis, important for lipid metabolism/transport, host cell invasion, modulation of host immune response and pathogenicity, is under the transcriptional control of Mce1R. Hence characterizing Mce1R is an important step for novel anti-tuberculosis drug discovery. The present study reports functional and in silico characterization of Mce1R. In this work, we have computationally modeled the structure of Mce1R and have validated the structure by computational and experimental methods. Mce1R has been shown to harbor the canonical VanR-like structure with a flexible N-terminal 'arm', carrying conserved positively charged residues, most likely involved in the operator DNA binding. The mce1R gene has been cloned, expressed, purified and its DNA-binding activity has been measured in vitro. The Kd value for Mce1R-operator DNA interaction has been determined to be 0.35 ± 0.02 µM which implies that Mce1R binds to DNA with moderate affinity compared to the other FCD family of regulators. So far, this is the first report for measuring the DNA-binding affinity of any VanR-type protein. Despite significant sequence similarity at the N-terminal domain, the wHTH motif of Mce1R exhibits poor conservancy of amino acid residues, critical for DNA-binding, thus results in moderate DNA-binding affinity. The N-terminal DNA-binding domain is structurally dynamic while the C-terminal domain showed significant stability and such profile of structural dynamics is most likely to be preserved in the structural orthologs of Mce1R. In addition to this, a cavity has been detected in the C-terminal domain of Mce1R which contains a few conserved residues. Comparison with other FCD family of regulators suggests that most of the conserved residues might be critical for binding to specific ligand. The max pKd value and drug score for the cavity are estimated to be 9.04 and 109 respectively suggesting that the cavity represents a suitable target site for novel anti-tuberculosis drug discovery approaches.
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18
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Coexpression of MmpS5 and MmpL5 Contributes to Both Efflux Transporter MmpL5 Trimerization and Drug Resistance in Mycobacterium tuberculosis. mSphere 2021; 6:6/1/e00518-20. [PMID: 33408221 PMCID: PMC7845600 DOI: 10.1128/msphere.00518-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
It has been reported that mycobacterial membrane protein large 5 (MmpL5), a resistance-nodulation-division (RND)-type inner membrane transporter in Mycobacterium tuberculosis (Mtb), is involved in the transport of antimycobacterial drugs. However, the functional roles of the membrane fusion protein mycobacterial membrane protein small 5 (MmpS5), organized as an operon with MmpL5, are unclear. The increasing occurrence of multidrug-resistant Mycobacterium tuberculosis (Mtb) is a serious threat to global public health. Among the many mechanisms of drug resistance, only resistance-nodulation-division (RND)-type multidrug efflux systems can simultaneously render bacteria tolerant to numerous toxic compounds, including antibiotics. The elevated expression of RND-type xenobiotic efflux transporter complexes, which consist of an inner membrane transporter, membrane fusion protein, and outer membrane channel, plays a major role in multidrug resistance. Among the 14 mycobacterial membrane protein large (MmpL) proteins identified as inner membrane transporters of Mtb, MmpL5 is known to participate in the acquisition of resistance to bedaquiline and clofazimine. MmpL5 exports these drugs by forming a complex with the membrane fusion protein mycobacterial membrane protein small 5 (MmpS5). However, the role of MmpS5 in the efflux of antituberculous drugs by MmpL5 remains unclear. In this study, we focused on the in vivo dynamics of MmpL5 using green fluorescent protein (GFP). Single-molecule observations of MmpL5 showed substantial lateral displacements of MmpL5-GFP without the expression of MmpS5. Nondiffusing MmpL5-GFP foci typically showed three-step photobleaching, suggesting that MmpL5 formed a homotrimeric functional complex on the inner membrane in the presence of MmpS5. These results suggest that the expression of MmpS5 facilitates the assembly of monomeric MmpL5 into a homotrimer that is anchored to the inner membrane to transport various antimycobacterial drugs. IMPORTANCE It has been reported that mycobacterial membrane protein large 5 (MmpL5), a resistance-nodulation-division (RND)-type inner membrane transporter in Mycobacterium tuberculosis (Mtb), is involved in the transport of antimycobacterial drugs. However, the functional roles of the membrane fusion protein mycobacterial membrane protein small 5 (MmpS5), organized as an operon with MmpL5, are unclear. Via the single-molecule imaging of MmpL5, we uncovered the maintenance of the functional trimeric complex structure of MmpL5 in the presence of MmpS5. These findings demonstrate that the assembly mechanisms of mycobacterial RND efflux systems are the dynamically regulated process through interactions among the components. This represents the first report of the single-molecule observation of Mtb efflux transporters, which may enhance our understanding of innate antibiotic resistance.
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19
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Modeling Tubercular ESX-1 Secretion Using Mycobacterium marinum. Microbiol Mol Biol Rev 2020; 84:84/4/e00082-19. [DOI: 10.1128/mmbr.00082-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pathogenic mycobacteria cause chronic and acute diseases ranging from human tuberculosis (TB) to nontubercular infections.
Mycobacterium tuberculosis
causes both acute and chronic human tuberculosis. Environmentally acquired nontubercular mycobacteria (NTM) cause chronic disease in humans and animals. Not surprisingly, NTM and
M. tuberculosis
often use shared molecular mechanisms to survive within the host. The ESX-1 system is a specialized secretion system that is essential for virulence and is functionally conserved between
M. tuberculosis
and
Mycobacterium marinum
.
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20
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Dunlap MD, Prince OA, Rangel-Moreno J, Thomas KA, Scordo JM, Torrelles JB, Cox J, Steyn AJC, Zúñiga J, Kaushal D, Khader SA. Formation of Lung Inducible Bronchus Associated Lymphoid Tissue Is Regulated by Mycobacterium tuberculosis Expressed Determinants. Front Immunol 2020; 11:1325. [PMID: 32695111 PMCID: PMC7338767 DOI: 10.3389/fimmu.2020.01325] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 05/26/2020] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the causative agent of the infectious disease tuberculosis (TB), which is a leading cause of death worldwide. Approximately one fourth of the world's population is infected with Mtb. A major unresolved question is delineating the inducers of protective long-lasting immune response without inducing overt, lung inflammation. Previous studies have shown that the presence of inducible Bronchus-Associated Lymphoid Tissue (iBALT) correlate with protection from Mtb infection. In this study, we hypothesized that specific Mtb factors could influence the formation of iBALT, thus skewing the outcome of TB disease. We infected non-human primates (NHPs) with a transposon mutant library of Mtb, and identified specific Mtb mutants that were over-represented within iBALT-containing granulomas. A major pathway reflected in these mutants was Mtb cell wall lipid transport and metabolism. We mechanistically addressed the function of one such Mtb mutant lacking mycobacteria membrane protein large 7 (MmpL7), which transports phthiocerol dimycocerosate (PDIM) to the mycobacterial outer membrane (MOM). Accordingly, murine aerosol infection with the Mtb mutant Δmmpl7 correlated with increased iBALT-containing granulomas. Our studies showed that the Δmmpl7 mutant lacking PDIMs on the surface overexpressed diacyl trehaloses (DATs) in the cell wall, which altered the cytokine/chemokine production of epithelial and myeloid cells, thus leading to a dampened inflammatory response. Thus, this study describes an Mtb specific factor that participates in the induction of iBALT formation during TB by directly modulating cytokine and chemokine production in host cells.
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Affiliation(s)
- Micah D Dunlap
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Oliver A Prince
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | | | - Kimberly A Thomas
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Julia M Scordo
- Texas Biomedical Research Institute, San Antonio, TX, United States
| | | | - Jeffery Cox
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Adrie J C Steyn
- Department of Microbiology, Centers for AIDS Research and Free Radical Biology, University of Alabama at Alabama, Birmingham, AL, United States.,African Health Research Institute (AHRI), Durban, South Africa
| | - Joaquín Zúñiga
- Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico
| | - Deepak Kaushal
- Texas Biomedical Research Institute, San Antonio, TX, United States.,Division of Bacteriology, Tulane National Primate Research Center, Covington, LA, United States.,Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Shabaana A Khader
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, United States
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21
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Ma S, Huang Y, Xie F, Gong Z, Zhang Y, Stojkoska A, Xie J. Transport mechanism of Mycobacterium tuberculosis MmpL/S family proteins and implications in pharmaceutical targeting. Biol Chem 2020; 401:331-348. [DOI: 10.1515/hsz-2019-0326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 09/06/2019] [Indexed: 12/13/2022]
Abstract
AbstractTuberculosis caused by Mycobacterium tuberculosis remains a serious threat to public health. The M. tuberculosis cell envelope is closely related to its virulence and drug resistance. Mycobacterial membrane large proteins (MmpL) are lipid-transporting proteins of the efflux pump resistance nodulation cell division (RND) superfamily with lipid substrate specificity and non-transport lipid function. Mycobacterial membrane small proteins (MmpS) are small regulatory proteins, and they are also responsible for some virulence-related effects as accessory proteins of MmpL. The MmpL transporters are the candidate targets for the development of anti-tuberculosis drugs. This article summarizes the structure, function, phylogenetics of M. tuberculosis MmpL/S proteins and their roles in host immune response, inhibitors and regulatory system.
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Affiliation(s)
- Shuang Ma
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Yu Huang
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Fuling Xie
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Zhen Gong
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Yuan Zhang
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Andrea Stojkoska
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, 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, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
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22
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Abstract
The causative agent of human tuberculosis, Mycobacterium tuberculosis, has a complex lipid-rich diderm envelope, which acts as a major barrier protecting the bacterium against the hostile environment inside the host cells. For the transfer of diverse molecules across this complex cell envelope, M. tuberculosis has a series of general and specialized protein secretion systems, characterized by the SecA general secretion pathway, the twin-arginine translocation pathway, and five specific ESX type VII secretion systems. In this review, we focus on the latter systems, known as ESX-1 to ESX-5, which were first discovered almost 20 years ago during the in silico analysis of the genome sequence of M. tuberculosis H37Rv. Since then, these systems have been the subject of highly dynamic research due to their involvement in several key biological processes and host-pathogen interactions of the tubercle bacilli.
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23
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TbD1 deletion as a driver of the evolutionary success of modern epidemic Mycobacterium tuberculosis lineages. Nat Commun 2020; 11:684. [PMID: 32019932 PMCID: PMC7000671 DOI: 10.1038/s41467-020-14508-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 01/09/2020] [Indexed: 11/29/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) strains are classified into different phylogenetic lineages (L), three of which (L2/L3/L4) emerged from a common progenitor after the loss of the MmpS6/MmpL6-encoding Mtb-specific deletion 1 region (TbD1). These TbD1-deleted “modern” lineages are responsible for globally-spread tuberculosis epidemics, whereas TbD1-intact “ancestral” lineages tend to be restricted to specific geographical areas, such as South India and South East Asia (L1) or East Africa (L7). By constructing and characterizing a panel of recombinant TbD1-knock-in and knock-out strains and comparison with clinical isolates, here we show that deletion of TbD1 confers to Mtb a significant increase in resistance to oxidative stress and hypoxia, which correlates with enhanced virulence in selected cellular, guinea pig and C3HeB/FeJ mouse infection models, the latter two mirroring in part the development of hypoxic granulomas in human disease progression. Our results suggest that loss of TbD1 at the origin of the L2/L3/L4 Mtb lineages was a key driver for their global epidemic spread and outstanding evolutionary success. Mycobacterium tuberculosis (Mtb) modern strains emerged from a common progenitor after the loss of Mtb-specific deletion 1 region (TbD1). Here, the authors show that deletion of TbD1 correlates with enhanced Mtb virulence in animal models, mirroring the development of hypoxic granulomas in human disease progression.
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Abstract
ABSTRACT
Mycobacteria, including the infamous pathogen
Mycobacterium tuberculosis
, are high-GC Gram-positive bacteria with a distinctive cell envelope. Although there is a typical inner membrane, the mycobacterial cell envelope is unusual in having its peptidoglycan layer connected to a polymer of arabinogalactan, which in turn is covalently attached to long-chain mycolic acids that help form a highly impermeable mycobacterial outer membrane. This complex double-membrane, or diderm, cell envelope imparts mycobacteria with unique requirements for protein export into and across the cell envelope for secretion into the extracellular environment. In this article, we review the four protein export pathways known to exist in mycobacteria: two conserved systems that exist in all types of bacteria (the Sec and Tat pathways) and two specialized systems that exist in mycobacteria, corynebacteria, and a subset of low-GC Gram-positive bacteria (the SecA2 and type VII secretion pathways). We describe the progress made over the past 15 years in understanding each of these mycobacterial export pathways, and we highlight the need for research to understand the specific steps of protein export across the mycobacterial outer membrane.
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25
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Kim BJ, Cha GY, Kim BR, Kook YH, Kim BJ. Insights From the Genome Sequence of Mycobacterium paragordonae, a Potential Novel Live Vaccine for Preventing Mycobacterial Infections: The Putative Role of Type VII Secretion Systems for an Intracellular Lifestyle Within Free-Living Environmental Predators. Front Microbiol 2019; 10:1524. [PMID: 31333625 PMCID: PMC6616192 DOI: 10.3389/fmicb.2019.01524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 06/18/2019] [Indexed: 12/31/2022] Open
Abstract
Mycobacterium paragordonae (Mpg) is a temperature-sensitive Mycobacterium species that can grow at permissive temperatures but fails to grow above 37°C. Due to this unique growth trait, Mpg has recently been proposed as a novel live vaccine candidate for the prevention of mycobacterial infections. Furthermore, the increasing frequency of the isolation of Mpg from water supply systems led us to hypothesize that the free-living amoeba system is the natural reservoir of Mpg. In this study, we report the complete 6.7-Mb genome sequence of Mpg and show that this genome comprises four different plasmids with lengths of 305 kb (pMpg-1), 144 kb (pMpg-2), 26 kb (pMpg-3), and 17 kb (pMpg-4). The first two plasmids, pMpg-1 and -2, encode distinct Type VII secretion systems (T7SS), ESX-P5 and ESX-2, respectively. Genome-based phylogeny indicated that Mpg is the closest relative to M. gordonae, which has a 7.7-Mb genome; phylogenetic analysis revealed an average of 86.68% nucleotide identity between these two species. The most important feature of Mpg genome is the acquisition of massive genes related to T7SS, which may have had effect on adaptation to their intracellular lifestyle within free-living environmental predators, such as amoeba. Comparisons of the resistance to bacterial killing within amoeba indicated that Mpg exhibited stronger resistance to amoeba killing compared to M. gordonae and M. marinum, further supporting our genome-based findings indicating the special adaptation of Mpg to free-living amoeba. We also determined that, among the strains studied, there were more shared CDS between M. tuberculosis and Mpg. In addition, the presence of diverse T7SSs in the Mpg genome, including an intact ESX-1, may suggest the feasibility of Mpg as a novel tuberculosis vaccine. Our data highlight a significant role of lateral gene transfer in the evolution of mycobacteria for niche diversification and for increasing the intracellular survival capacity.
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Affiliation(s)
- Byoung-Jun Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Ga-Yeong Cha
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Bo-Ram Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Yoon-Hoh Kook
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Bum-Joon Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
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Santucci P, Smichi N, Diomandé S, Poncin I, Point V, Gaussier H, Cavalier J, Kremer L, Canaan S. Dissecting the membrane lipid binding properties and lipase activity ofMycobacterium tuberculosisLipY domains. FEBS J 2019; 286:3164-3181. [DOI: 10.1111/febs.14864] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 03/25/2019] [Accepted: 04/25/2019] [Indexed: 12/29/2022]
Affiliation(s)
| | | | | | | | | | | | | | - Laurent Kremer
- Institut de Recherche en Infectiologie de Montpellier (IRIM) CNRS UMR9004 Université de Montpellier France
- INSERM IRIM Montpellier France
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Hussein SH, Samir R, Aziz RK, Toama MA. Two putative MmpL homologs contribute to antimicrobial resistance and nephropathy of enterohemorrhagic E. coli O157:H7. Gut Pathog 2019; 11:15. [PMID: 31019555 PMCID: PMC6471949 DOI: 10.1186/s13099-019-0296-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/27/2019] [Indexed: 11/11/2022] Open
Abstract
Background The serious human pathogen, E. coli serotype O157:H7, continues to gain antibiotic resistance, posing a public health threat. While this serotype’s genome has been sequenced, the role of 25% of its genes remains unknown, including genes conferring additional resistance. A prominent bacterial resistance mechanism is acquiring genes encoding efflux pumps, among which are the mycobacterial membrane proteins (Mmp), which contribute to virulence and membrane transport in mycobacteria. Here, we identified two potential mmp homologs (z4861 and yegN) in E. coli O157:H7, and we aimed to investigate their distribution among E. coli strains and their potential functions. Methods and results By screening different E. coli strains in vitro and in silico, we observed that yegN is more conserved than z4861. Using knockout mutants lacking either or both genes, we found that the mutants were more susceptible to fluoroquinolones than the parent strain and their secretomes included fewer virulence-related proteins. Moreover, histopathological examination of the kidneys of CD-1 mice infected by the wild-type or knockout strains indicated a greater impact of z4861 on pathogenesis and kidney damage than yegN, since both mutants lacking z4861 caused less severe kidney damage. The growth pattern of the wild-type was similar to that of mutant strains under aerobic and anaerobic conditions; yet, the mutant strains grew less when treated with subinhibitory dose of ciprofloxacin. Conclusion The previously unannotated gene product, Z4861, and its more conserved homolog, YegN, contribute to the kidney damage and resistance of E. coli O157:H7. Electronic supplementary material The online version of this article (10.1186/s13099-019-0296-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Salma H Hussein
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562 Egypt
| | - Reham Samir
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562 Egypt
| | - Ramy K Aziz
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562 Egypt
| | - Mohamed A Toama
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, 11562 Egypt
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Lopeman RC, Harrison J, Desai M, Cox JAG. Mycobacterium abscessus: Environmental Bacterium Turned Clinical Nightmare. Microorganisms 2019; 7:microorganisms7030090. [PMID: 30909391 PMCID: PMC6463083 DOI: 10.3390/microorganisms7030090] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 12/19/2022] Open
Abstract
Mycobacteria are a large family of over 100 species, most of which do not cause diseases in humans. The majority of the mycobacterial species are referred to as nontuberculous mycobacteria (NTM), meaning they are not the causative agent of tuberculous (TB) or leprosy, i.e., Mycobacterium tuberculous complex and Mycobacterium leprae, respectively. The latter group is undoubtedly the most infamous, with TB infecting an estimated 10 million people and causing over 1.2 million deaths in 2017 alone TB and leprosy also differ from NTM in that they are only transmitted from person to person and have no environmental reservoir, whereas NTM infections are commonly acquired from the environment. It took until the 1950′s for NTM to be recognised as a potential lung pathogen in people with underlying pulmonary disease and another three decades for NTM to be widely regarded by the medical community when Mycobacterium avium complex was identified as the most common group of opportunistic pathogens in AIDS patients. This review focuses on an emerging NTM called Mycobacterium abscessus (M. abs). M. abs is a rapidly growing NTM that is responsible for opportunistic pulmonary infections in patients with structural lung disorders such as cystic fibrosis and bronchiectasis, as well as a wide range of skin and soft tissue infections in humans. In this review, we discuss how we came to understand the pathogen, how it is currently treated and examine drug resistance mechanisms and novel treatments currently in development. We highlight the urgent need for new and effective treatments for M. abs infection as well as improved in vivo methods of efficacy testing.
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Affiliation(s)
- Rose C Lopeman
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
| | - James Harrison
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
| | - Maya Desai
- Birmingham Children's Hospital, Birmingham Women's and Children's NHS Foundation Trust, Steelhouse Lane, Birmingham B4 6NH, UK.
| | - Jonathan A G Cox
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK.
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Melly G, Purdy GE. MmpL Proteins in Physiology and Pathogenesis of M. tuberculosis. Microorganisms 2019; 7:microorganisms7030070. [PMID: 30841535 PMCID: PMC6463170 DOI: 10.3390/microorganisms7030070] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/14/2019] [Accepted: 03/03/2019] [Indexed: 11/16/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) remains an important human pathogen. The Mtb cell envelope is a critical bacterial structure that contributes to virulence and pathogenicity. Mycobacterial membrane protein large (MmpL) proteins export bulky, hydrophobic substrates that are essential for the unique structure of the cell envelope and directly support the ability of Mtb to infect and persist in the host. This review summarizes recent investigations that have enabled insight into the molecular mechanisms underlying MmpL substrate export and the role that these substrates play during Mtb infection.
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Affiliation(s)
- Geoff Melly
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Georgiana E Purdy
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR 97239, USA.
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Meena LS. Interrelation of Ca2+ and PE_PGRS proteins during Mycobacterium tuberculosis pathogenesis. J Biosci 2019. [DOI: 10.1007/s12038-018-9828-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Madacki J, Laval F, Grzegorzewicz A, Lemassu A, Záhorszká M, Arand M, McNeil M, Daffé M, Jackson M, Lanéelle MA, Korduláková J. Impact of the epoxide hydrolase EphD on the metabolism of mycolic acids in mycobacteria. J Biol Chem 2018; 293:5172-5184. [PMID: 29472294 DOI: 10.1074/jbc.ra117.000246] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/16/2018] [Indexed: 01/09/2023] Open
Abstract
Mycolic acids are the hallmark of the cell envelope in mycobacteria, which include the important human pathogens Mycobacterium tuberculosis and Mycobacterium leprae Mycolic acids are very long C60-C90 α-alkyl β-hydroxy fatty acids having a variety of functional groups on their hydrocarbon chain that define several mycolate types. Mycobacteria also produce an unusually large number of putative epoxide hydrolases, but the physiological functions of these enzymes are still unclear. Here, we report that the mycobacterial epoxide hydrolase EphD is involved in mycolic acid metabolism. We found that orthologs of EphD from M. tuberculosis and M. smegmatis are functional epoxide hydrolases, cleaving a lipophilic substrate, 9,10-cis-epoxystearic acid, in vitro and forming a vicinal diol. The results of EphD overproduction in M. smegmatis and M. bovis BCG Δhma strains producing epoxymycolic acids indicated that EphD is involved in the metabolism of these forms of mycolates in both fast- and slow-growing mycobacteria. Moreover, using MALDI-TOF-MS and 1H NMR spectroscopy of mycolic acids and lipids isolated from EphD-overproducing M. smegmatis, we identified new oxygenated mycolic acid species that accumulated during epoxymycolate depletion. Disruption of the ephD gene in M. tuberculosis specifically impaired the synthesis of ketomycolates and caused accumulation of their precursor, hydroxymycolate, indicating either direct or indirect involvement of EphD in ketomycolate biosynthesis. Our results clearly indicate that EphD plays a role in metabolism of oxygenated mycolic acids in mycobacteria.
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Affiliation(s)
- Jan Madacki
- From the Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia
| | - Françoise Laval
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Anna Grzegorzewicz
- the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, and
| | - Anne Lemassu
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Monika Záhorszká
- From the Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia
| | - Michael Arand
- the Institute of Pharmacology and Toxicology, University of Zürich, CH-8057 Zürich, Switzerland
| | - Michael McNeil
- the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, and
| | - Mamadou Daffé
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Mary Jackson
- the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, and
| | - Marie-Antoinette Lanéelle
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Jana Korduláková
- From the Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia,
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Zhou P, Wang X, Zhao Y, Yuan W, Xie J. Sigma factors mediated signaling in Mycobacterium tuberculosis. Future Microbiol 2018; 13:231-240. [DOI: 10.2217/fmb-2017-0127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Activation of signaling cascades is critical for Mycobacterium tuberculosis (Mtb) to adapt the macrophage lifestyle. Parallel to several signal systems, sigma factor systems, especially the extra-cytoplasmic function sigma factors, are crucial for Mtb signaling. Most sigma factors lack a signal sensory domain and often are activated by various proteins that perceive the environmental cues and relay the signals through variegated post-translational modifications via the activity of antisigma factor, protein kinase and related transcriptional regulators. Antisigma factors are further controlled by multiple mechanisms. SigK senses the environmental redox state directly. Phosphorylation and lysine acetylation added another dimension to the regulatory hierarchy. This review will provide insights into Mtb pathogenesis, and lay the foundation for the discovery of novel approaches for therapeutic interventions.
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Affiliation(s)
- Peifu Zhou
- Institute of Ethnic-Minority Medicine, School of Ethnic-Minority Medicine, Guizhou Minzu University, Guiyang 550025, PR China
| | - Xinpeng Wang
- School of Humanities & Sciences, Guizhou Minzu University, Guiyang 550025, PR China
| | - Yuzhong Zhao
- Institute of Ethnic-Minority Medicine, School of Ethnic-Minority Medicine, Guizhou Minzu University, Guiyang 550025, PR China
| | - Wei Yuan
- Institute of Tuberculosis Control & Prevention, Guizhou Provincial Center for Disease Control & Prevention, Guiyang 550004, PR China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, School of Life Sciences, Southwest University, Chongqing 400715, PR China
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Briffotaux J, Huang W, Wang X, Gicquel B. MmpS5/MmpL5 as an efflux pump in Mycobacterium species. Tuberculosis (Edinb) 2017; 107:13-19. [DOI: 10.1016/j.tube.2017.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/31/2017] [Accepted: 08/03/2017] [Indexed: 10/19/2022]
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Sandhu P, Akhter Y. Evolution of structural fitness and multifunctional aspects of mycobacterial RND family transporters. Arch Microbiol 2017; 200:19-31. [PMID: 28951954 DOI: 10.1007/s00203-017-1434-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/07/2017] [Accepted: 09/20/2017] [Indexed: 12/11/2022]
Abstract
Drug resistance is a major concern due to the evolution and emergence of pathogenic bacterial strains with novel strategies to resist the antibiotics in use. Mycobacterium tuberculosis (Mtb) is one of such pathogens with reported strains, which are not treatable with any of the available anti-TB drugs. This scenario has led to the need to look for some novel drug targets in Mtb, which may be exploited to design effective treatment strategies against the infection. The goal of this review is to discuss one such class of emerging drug targets in Mtb. MmpL (mycobacterial membrane protein large) proteins from Mtb are reported to be involved in multi-substrate transport including drug efflux and considered as one of the contributing factors for the emergence of multidrug-resistant strains. MmpL proteins belong to resistance nodulation division permeases superfamily of membrane transporters, which are viably and pathogenetically important and their inhibition could be lethal for the bacteria.
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Affiliation(s)
- Padmani Sandhu
- Structural Bioinformatics Group, Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Shahpur District, Kangra, Himachal Pradesh, 176206, India
| | - Yusuf Akhter
- Structural Bioinformatics Group, Centre for Computational Biology and Bioinformatics, School of Life Sciences, Central University of Himachal Pradesh, Shahpur District, Kangra, Himachal Pradesh, 176206, India.
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Protein Secretion in Gram-Positive Bacteria: From Multiple Pathways to Biotechnology. Curr Top Microbiol Immunol 2017; 404:267-308. [PMID: 27885530 DOI: 10.1007/82_2016_49] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A number of Gram-positive bacteria are important players in industry as producers of a diverse array of economically interesting metabolites and proteins. As discussed in this overview, several Gram-positive bacteria are valuable hosts for the production of heterologous proteins. In contrast to Gram-negative bacteria, proteins secreted by Gram-positive bacteria are released into the culture medium where conditions for correct folding are more appropriate, thus facilitating the isolation and purification of active proteins. Although seven different protein secretion pathways have been identified in Gram-positive bacteria, the majority of heterologous proteins are produced via the general secretion or Sec pathway. Not all proteins are equally well secreted, because heterologous protein production often faces bottlenecks including hampered secretion, susceptibility to proteases, secretion stress, and metabolic burden. These bottlenecks are associated with reduced yields leading to non-marketable products. In this chapter, besides a general overview of the different protein secretion pathways, possible hurdles that may hinder efficient protein secretion are described and attempts to improve yield are discussed including modification of components of the Sec pathway. Attention is also paid to omics-based approaches that may offer a more rational approach to optimize production of heterologous proteins.
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36
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Singh P, Katoch VM, Mohanty KK, Chauhan DS. Analysis of expression profile of mce operon genes (mce1, mce2, mce3 operon) in different Mycobacterium tuberculosis isolates at different growth phases. Indian J Med Res 2017; 143:487-94. [PMID: 27377506 PMCID: PMC4928556 DOI: 10.4103/0971-5916.184305] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background & objectives: Mycobacterium tuberculosis (M. tuberculosis) has four homologous mammalian cell entry (mce) operons (mce1-4) that encode exported proteins and have a possible role in the virulence mechanism of this pathogen. The expression of mce operon is considered to be complex and not completely understood. Although expression of mce operon at different in vitro growth phases has been studied earlier, its expression in different M. tuberculosis isolates under different growth phases is not yet studied. The present preliminary study was conducted on a limited number of isolates to know the trend of expression pattern of mce operon genes in different M. tuberculosis isolates under different growth stages. Methods: In this study, we monitored the transcriptional profile of selected mce operon genes (mce1A, mce1D, mce2A, mce2D, mce3A, mce3C) in different M. tuberculosis isolates (MDR1, MDR2, and sensitive isolate) at early exponential and stationary phases using real-time quantitative PCR. Results: The expression ratio of all selected mce operon genes in all M. tuberculosis isolates was reduced at the initial phase and increased substantially at a later phase of growth. Higher expression of mce1 operon genes was found in all M. tuberculosis isolates as compared to other mce operon genes (mce2 and mce3 operons) at stationary growth phase. Interpretation & conclusions: The higher expression of mce operon genes at stationary phase (as compared to early exponential phase) suggested growth phase dependent expression of mce operon genes. This indicated that the mce operon genes might have a role in M. tuberculosis survival and adaptation on the onset of adverse condition like stationary phase. Identification of differentially expressed genes will add to our understanding of the bacilli involved in adaptation to different growth conditions.
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Affiliation(s)
- Pratibha Singh
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - V M Katoch
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra; Former Secretary, Department of Health Research and Director-General, ICMR, Ministry of Health & Family Welfare, Government of India, New Delhi, India
| | - K K Mohanty
- Department of Immunology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
| | - Devendra Singh Chauhan
- Department of Microbiology & Molecular Biology, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra, India
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Unnikrishnan M, Constantinidou C, Palmer T, Pallen MJ. The Enigmatic Esx Proteins: Looking Beyond Mycobacteria. Trends Microbiol 2017; 25:192-204. [DOI: 10.1016/j.tim.2016.11.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/20/2016] [Accepted: 11/04/2016] [Indexed: 01/17/2023]
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Peddireddy V, Doddam SN, Ahmed N. Mycobacterial Dormancy Systems and Host Responses in Tuberculosis. Front Immunol 2017; 8:84. [PMID: 28261197 PMCID: PMC5309233 DOI: 10.3389/fimmu.2017.00084] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/18/2017] [Indexed: 12/15/2022] Open
Abstract
Tuberculosis (TB) caused by the intracellular pathogen, Mycobacterium tuberculosis (Mtb), claims more than 1.5 million lives worldwide annually. Despite promulgation of multipronged strategies to prevent and control TB, there is no significant downfall occurring in the number of new cases, and adding to this is the relapse of the disease due to the emergence of antibiotic resistance and the ability of Mtb to remain dormant after primary infection. The pathology of Mtb is complex and largely attributed to immune-evading strategies that this pathogen adopts to establish primary infection, its persistence in the host, and reactivation of pathogenicity under favorable conditions. In this review, we present various biochemical, immunological, and genetic strategies unleashed by Mtb inside the host for its survival. The bacterium enables itself to establish a niche by evading immune recognition via resorting to masking, establishment of dormancy by manipulating immune receptor responses, altering innate immune cell fate, enhancing granuloma formation, and developing antibiotic tolerance. Besides these, the regulatory entities, such as DosR and its regulon, encompassing various putative effector proteins play a vital role in maintaining the dormant nature of this pathogen. Further, reactivation of Mtb allows relapse of the disease and is favored by the genes of the Rtf family and the conditions that suppress the immune system of the host. Identification of target genes and characterizing the function of their respective antigens involved in primary infection, dormancy, and reactivation would likely provide vital clues to design novel drugs and/or vaccines for the control of dormant TB.
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Affiliation(s)
- Vidyullatha Peddireddy
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad , Hyderabad , India
| | - Sankara Narayana Doddam
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad , Hyderabad , India
| | - Niyaz Ahmed
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, India; Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
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Conrad WH, Osman MM, Shanahan JK, Chu F, Takaki KK, Cameron J, Hopkinson-Woolley D, Brosch R, Ramakrishnan L. Mycobacterial ESX-1 secretion system mediates host cell lysis through bacterium contact-dependent gross membrane disruptions. Proc Natl Acad Sci U S A 2017; 114:1371-1376. [PMID: 28119503 PMCID: PMC5307465 DOI: 10.1073/pnas.1620133114] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis and Mycobacterium marinum are thought to exert virulence, in part, through their ability to lyse host cell membranes. The type VII secretion system ESX-1 [6-kDa early secretory antigenic target (ESAT-6) secretion system 1] is required for both virulence and host cell membrane lysis. Both activities are attributed to the pore-forming activity of the ESX-1-secreted substrate ESAT-6 because multiple studies have reported that recombinant ESAT-6 lyses eukaryotic membranes. We too find ESX-1 of M. tuberculosis and M. marinum lyses host cell membranes. However, we find that recombinant ESAT-6 does not lyse cell membranes. The lytic activity previously attributed to ESAT-6 is due to residual detergent in the preparations. We report here that ESX-1-dependent cell membrane lysis is contact dependent and accompanied by gross membrane disruptions rather than discrete pores. ESX-1-mediated lysis is also morphologically distinct from the contact-dependent lysis of other bacterial secretion systems. Our findings suggest redirection of research to understand the mechanism of ESX-1-mediated lysis.
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Affiliation(s)
- William H Conrad
- Department of Medicine, University of Cambridge, Cambridge CB2 0QH, United Kingdom
| | - Morwan M Osman
- Department of Medicine, University of Cambridge, Cambridge CB2 0QH, United Kingdom
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98105
| | - Jonathan K Shanahan
- Department of Medicine, University of Cambridge, Cambridge CB2 0QH, United Kingdom
- Wellcome Trust PhD Program in Infection, Immunity, and Inflammation, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Frances Chu
- Department of Microbiology, University of Washington, Seattle, WA 98105
| | - Kevin K Takaki
- Department of Medicine, University of Cambridge, Cambridge CB2 0QH, United Kingdom
| | - James Cameron
- Department of Microbiology, University of Washington, Seattle, WA 98105
| | | | - Roland Brosch
- Unit for Integrated Mycobacterial Pathogenomics, Institut Pasteur, 75015 Paris, France
| | - Lalita Ramakrishnan
- Department of Medicine, University of Cambridge, Cambridge CB2 0QH, United Kingdom;
- Department of Microbiology, University of Washington, Seattle, WA 98105
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Pandey H, Tripathi S, Srivastava K, Tripathi DK, Srivastava M, Kant S, Srivastava KK, Arora A. Characterization of culture filtrate proteins Rv1197 and Rv1198 of ESAT-6 family from Mycobacterium tuberculosis H37Rv. Biochim Biophys Acta Gen Subj 2017; 1861:396-408. [DOI: 10.1016/j.bbagen.2016.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 10/01/2016] [Accepted: 10/13/2016] [Indexed: 12/15/2022]
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Abstract
Mycobacterium tuberculosis uses sophisticated secretion systems, named 6 kDa early secretory antigenic target (ESAT6) protein family secretion (ESX) systems (also known as type VII secretion systems), to export a set of effector proteins that helps the pathogen to resist or evade the host immune response. Since the discovery of the esx loci during the M. tuberculosis H37Rv genome project, structural biology, cell biology and evolutionary analyses have advanced our knowledge of the function of these systems. In this Review, we highlight the intriguing roles that these studies have revealed for ESX systems in bacterial survival and pathogenicity during infection with M. tuberculosis. Furthermore, we discuss the diversity of ESX systems that has been described among mycobacteria and selected non-mycobacterial species. Finally, we consider how our knowledge of ESX systems might be applied to the development of novel strategies for the treatment and prevention of disease.
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Becker K, Sander P. Mycobacterium tuberculosis lipoproteins in virulence and immunity - fighting with a double-edged sword. FEBS Lett 2016; 590:3800-3819. [PMID: 27350117 DOI: 10.1002/1873-3468.12273] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/06/2016] [Accepted: 06/26/2016] [Indexed: 02/06/2023]
Abstract
Bacterial lipoproteins are secreted membrane-anchored proteins characterized by a lipobox motif. This lipobox motif directs post-translational modifications at the conserved cysteine through the consecutive action of three enzymes: Lgt, LspA and Lnt, which results in di- or triacylated forms. Lipoproteins are abundant in all bacteria including Mycobacterium tuberculosis and often involved in virulence and immunoregulatory processes. On the one hand, disruption of the biosynthesis pathway of lipoproteins leads to attenuation of M. tuberculosis in vivo, and mycobacteria deficient for certain lipoproteins have been assessed as attenuated live vaccine candidates. On the other hand, several mycobacterial lipoproteins form immunodominant antigens which promote an immune response. Some of these have been explored in DNA or subunit vaccination approaches against tuberculosis. The immune recognition of specific lipoproteins, however, might also benefit long-term survival of M. tuberculosis through immune modulation, while others induce protective responses. Exploiting lipoproteins as vaccines is thus a complex matter which requires deliberative investigation. The dual role of lipoproteins in the immunity to and pathogenicity of mycobacteria is discussed here.
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Affiliation(s)
- Katja Becker
- Institute of Medical Microbiology, University of Zurich, Switzerland
| | - Peter Sander
- Institute of Medical Microbiology, University of Zurich, Switzerland
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Newton-Foot M, Warren RM, Sampson SL, van Helden PD, Gey van Pittius NC. The plasmid-mediated evolution of the mycobacterial ESX (Type VII) secretion systems. BMC Evol Biol 2016; 16:62. [PMID: 26979252 PMCID: PMC4791881 DOI: 10.1186/s12862-016-0631-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/06/2016] [Indexed: 11/17/2022] Open
Abstract
Background The genome of Mycobacterium tuberculosis contains five copies of the ESX gene cluster, each encoding a dedicated protein secretion system. These ESX secretion systems have been defined as a novel Type VII secretion machinery, responsible for the secretion of proteins across the characteristic outer mycomembrane of the mycobacteria. Some of these secretion systems are involved in virulence and survival in M. tuberculosis; however they are also present in other non-pathogenic mycobacteria, and have been identified in some non-mycobacterial actinomycetes. Three components of the ESX gene cluster have also been found clustered in some gram positive monoderm organisms and are predicted to have preceded the ESX gene cluster. Results This study used in silico and phylogenetic analyses to describe the evolution of the ESX gene cluster from the WXG-FtsK cluster of monoderm bacteria to the five ESX clusters present in M. tuberculosis and other slow-growing mycobacteria. The ancestral gene cluster, ESX-4, was identified in several nonmycomembrane producing actinobacteria as well as the mycomembrane-containing Corynebacteriales in which the ESX cluster began to evolve and diversify. A novel ESX gene cluster, ESX-4EVOL, was identified in some non-mycobacterial actinomycetes and M. abscessus subsp. bolletii. ESX-4EVOL contains all of the conserved components of the ESX gene cluster and appears to be a precursor of the mycobacterial ESX duplications. Between two and seven ESX gene clusters were identified in each mycobacterial species, with ESX-2 and ESX-5 specifically associated with the slow growers. The order of ESX duplication in the mycobacteria is redefined as ESX-4, ESX-3, ESX-1 and then ESX-2 and ESX-5. Plasmid-encoded precursor ESX gene clusters were identified for each of the genomic ESX-3, -1, -2 and -5 gene clusters, suggesting a novel plasmid-mediated mechanism of ESX duplication and evolution. Conclusions The influence of the various ESX gene clusters on vital biological and virulence-related functions has clearly influenced the diversification and success of the various mycobacterial species, and their evolution from the non-pathogenic fast-growing saprophytic to the slow-growing pathogenic organisms. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0631-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mae Newton-Foot
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SAMRC Centre for Molecular and Cellular Biology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa.
| | - Robin Mark Warren
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SAMRC Centre for Molecular and Cellular Biology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Samantha Leigh Sampson
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SAMRC Centre for Molecular and Cellular Biology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Paul David van Helden
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SAMRC Centre for Molecular and Cellular Biology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Nicolaas Claudius Gey van Pittius
- Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SAMRC Centre for Molecular and Cellular Biology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
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Dumas E, Christina Boritsch E, Vandenbogaert M, Rodríguez de la Vega RC, Thiberge JM, Caro V, Gaillard JL, Heym B, Girard-Misguich F, Brosch R, Sapriel G. Mycobacterial Pan-Genome Analysis Suggests Important Role of Plasmids in the Radiation of Type VII Secretion Systems. Genome Biol Evol 2016; 8:387-402. [PMID: 26748339 PMCID: PMC4779608 DOI: 10.1093/gbe/evw001] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In mycobacteria, various type VII secretion systems corresponding to different ESX (ESAT-6 secretory) types, are contributing to pathogenicity, iron acquisition, and/or conjugation. In addition to the known chromosomal ESX loci, the existence of plasmid-encoded ESX systems was recently reported. To investigate the potential role of ESX-encoding plasmids on mycobacterial evolution, we analyzed a large representative collection of mycobacterial genomes, including both chromosomal and plasmid-borne sequences. Data obtained for chromosomal ESX loci confirmed the previous five classical ESX types and identified a novel mycobacterial ESX-4-like type, termed ESX-4-bis. Moreover, analysis of the plasmid-encoded ESX loci showed extensive diversification, with at least seven new ESX profiles, identified. Three of them (ESX-P clusters 1–3) were found in multiple plasmids, while four corresponded to singletons. Our phylogenetic and gene-order-analyses revealed two main groups of ESX types: 1) ancestral types, including ESX-4 and ESX-4-like systems from mycobacterial and non-mycobacterial actinobacteria and 2) mycobacteria-specific ESX systems, including ESX-1-2-3-5 systems and the plasmid-encoded ESX types. Synteny analysis revealed that ESX-P systems are part of phylogenetic groups that derived from a common ancestor, which diversified and resulted in the different ESX types through extensive gene rearrangements. A converging body of evidence, derived from composition bias-, phylogenetic-, and synteny analyses points to a scenario in which ESX-encoding plasmids have been a major driving force for acquisition and diversification of type VII systems in mycobacteria, which likely played (and possibly still play) important roles in the adaptation to new environments and hosts during evolution of mycobacterial pathogenesis.
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Affiliation(s)
- Emilie Dumas
- INSERM U1173, UFR Simone Weil, Versailles-Saint-en-Quentin University, Saint-Quentin-en-Yvelines 78180, France
| | - Eva Christina Boritsch
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, 75724, Paris Cedex 15, France
| | - Mathias Vandenbogaert
- Institut Pasteur, Genotyping of Pathogens and Public Health, 75724, Paris Cedex 15, France
| | | | - Jean-Michel Thiberge
- Institut Pasteur, Genotyping of Pathogens and Public Health, 75724, Paris Cedex 15, France
| | - Valerie Caro
- Institut Pasteur, Genotyping of Pathogens and Public Health, 75724, Paris Cedex 15, France
| | - Jean-Louis Gaillard
- INSERM U1173, UFR Simone Weil, Versailles-Saint-en-Quentin University, Saint-Quentin-en-Yvelines 78180, France AP-HP, Hôpital Ambroise Paré, Service De Microbiologie Et Hygiène, Boulogne-Billancourt, France
| | - Beate Heym
- INSERM U1173, UFR Simone Weil, Versailles-Saint-en-Quentin University, Saint-Quentin-en-Yvelines 78180, France AP-HP, Hôpital Ambroise Paré, Service De Microbiologie Et Hygiène, Boulogne-Billancourt, France
| | - Fabienne Girard-Misguich
- INSERM U1173, UFR Simone Weil, Versailles-Saint-en-Quentin University, Saint-Quentin-en-Yvelines 78180, France
| | - Roland Brosch
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, 75724, Paris Cedex 15, France
| | - Guillaume Sapriel
- INSERM U1173, UFR Simone Weil, Versailles-Saint-en-Quentin University, Saint-Quentin-en-Yvelines 78180, France UMR 8212, LSCE, Versailles-Saint-Quentin University, Saint-Quentin-en-Yvelines 78180, France Atelier De Bio-Informatique. Institut De Systématique, Evolution, Biodiversité, ISYEB, UMR 7205, CNRS, MNHN, UPMC, EPHE. Muséum National D'histoire Naturelle, Cedex 05, Paris 75231, France
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Abstract
Most mycobacterial species are harmless saprophytes, often found in aquatic environments. A few species seem to have evolved from this pool of environmental mycobacteria into major human pathogens, such as Mycobacterium tuberculosis, the agent of tuberculosis, Mycobacterium leprae, the leprosy bacillus, and Mycobacterium ulcerans, the agent of Buruli ulcer. While the pathogenicity of M. ulcerans relates to the acquisition of a large plasmid encoding a polyketide-derived toxin, the molecular mechanisms by which M. leprae or M. tuberculosis have evolved to cause disease are complex and involve the interaction between the pathogen and the host. Here we focus on M. tuberculosis and closely related mycobacteria and discuss insights gained from recent genomic and functional studies. Comparison of M. tuberculosis genome data with sequences from nontuberculous mycobacteria, such as Mycobacterium marinum or Mycobacterium kansasii, provides a perception of the more distant evolution of M. tuberculosis, while the recently accomplished genome sequences of multiple tubercle bacilli with smooth colony morphology, named Mycobacterium canettii, have allowed the ancestral gene pool of tubercle bacilli to be estimated. The resulting findings are instrumental for our understanding of the pathogenomic evolution of tuberculosis-causing mycobacteria. Comparison of virulent and attenuated members of the M. tuberculosis complex has further contributed to identification of a specific secretion pathway, named ESX or Type VII secretion. The molecular machines involved are key elements for mycobacterial pathogenicity, strongly influencing the ability of M. tuberculosis to cope with the immune defense mounted by the host.
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46
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Majlessi L, Prados-Rosales R, Casadevall A, Brosch R. Release of mycobacterial antigens. Immunol Rev 2015; 264:25-45. [PMID: 25703550 DOI: 10.1111/imr.12251] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mycobacterium tuberculosis has evolved from a Mycobacterium canettii-like progenitor pool into one of the most successful and widespread human pathogens. The pathogenicity of M. tuberculosis is linked to its ability to secrete/export/release selected mycobacterial proteins, and it is also established that active release of mycobacterial antigens is a prerequisite for strong immune recognition. Recent research has enabled mycobacterial secretion systems and vesicle-based release of mycobacterial antigens to be elucidated, which together with host-related specificities constitute key variables that determine the outcome of infection. Here, we discuss recently discovered, novel aspects on the nature and the regulation of antigen release of the tuberculosis agent with particular emphasis on the biological characterization of mycobacteria-specific ESX/type VII secretion systems and their secreted proteins, belonging to the Esx, PE, and PPE categories. The importance of specific mycobacterial antigen release is probably best exemplified by the striking differences observed between the cellular events during infection with the ESX-1-deficient, attenuated Mycobacterium bovis BCG compared to the virulent M. tuberculosis, which are clearly important for design of more specific diagnostics and more efficient vaccines.
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Affiliation(s)
- Laleh Majlessi
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, Paris, France
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47
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Chou TH, Delmar JA, Wright CC, Kumar N, Radhakrishnan A, Doh JK, Licon MH, Bolla JR, Lei HT, Rajashankar KR, Su CC, Purdy GE, Yu EW. Crystal structure of the Mycobacterium tuberculosis transcriptional regulator Rv0302. Protein Sci 2015; 24:1942-55. [PMID: 26362239 DOI: 10.1002/pro.2802] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/08/2015] [Accepted: 09/11/2015] [Indexed: 11/10/2022]
Abstract
Mycobacterium tuberculosis is a pathogenic bacterial species, which is neither Gram positive nor Gram negative. It has a unique cell wall, making it difficult to kill and conferring resistance to antibiotics that disrupt cell wall biosynthesis. Thus, the mycobacterial cell wall is critical to the virulence of these pathogens. Recent work shows that the mycobacterial membrane protein large (MmpL) family of transporters contributes to cell wall biosynthesis by exporting fatty acids and lipidic elements of the cell wall. The expression of the Mycobacterium tuberculosis MmpL proteins is controlled by a complicated regulatory network system. Here we report crystallographic structures of two forms of the TetR-family transcriptional regulator Rv0302, which participates in regulating the expression of MmpL proteins. The structures reveal a dimeric, two-domain molecule with architecture consistent with the TetR family of regulators. Comparison of the two Rv0302 crystal structures suggests that the conformational changes leading to derepression may be due to a rigid body rotational motion within the dimer interface of the regulator. Using fluorescence polarization and electrophoretic mobility shift assays, we demonstrate the recognition of promoter and intragenic regions of multiple mmpL genes by this protein. In addition, our isothermal titration calorimetry and electrophoretic mobility shift experiments indicate that fatty acids may be the natural ligand of this regulator. Taken together, these experiments provide new perspectives on the regulation of the MmpL family of transporters.
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Affiliation(s)
- Tsung-Han Chou
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011
| | - Jared A Delmar
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011
| | - Catherine C Wright
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, 97239
| | - Nitin Kumar
- Department of Chemistry, Iowa State University, Ames, Iowa, 50011
| | | | - Julia K Doh
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, 97239
| | - Meredith H Licon
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, 97239
| | - Jani Reddy Bolla
- Department of Chemistry, Iowa State University, Ames, Iowa, 50011
| | - Hsiang-Ting Lei
- Department of Chemistry, Iowa State University, Ames, Iowa, 50011
| | - Kanagalaghatta R Rajashankar
- NE-CAT and Department of Chemistry and Chemical Biology, Argonne National Laboratory, Cornell University, Argonne, Illinois, 60439
| | - Chih-Chia Su
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011
| | - Georgiana E Purdy
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, 97239
| | - Edward W Yu
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011.,Department of Chemistry, Iowa State University, Ames, Iowa, 50011
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48
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Delmar JA, Chou TH, Wright CC, Licon MH, Doh JK, Radhakrishnan A, Kumar N, Lei HT, Bolla JR, Rajashankar KR, Su CC, Purdy GE, Yu EW. Structural Basis for the Regulation of the MmpL Transporters of Mycobacterium tuberculosis. J Biol Chem 2015; 290:28559-28574. [PMID: 26396194 DOI: 10.1074/jbc.m115.683797] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Indexed: 11/06/2022] Open
Abstract
The mycobacterial cell wall is critical to the virulence of these pathogens. Recent work shows that the MmpL (mycobacterial membrane protein large) family of transporters contributes to cell wall biosynthesis by exporting fatty acids and lipidic elements of the cell wall. The expression of the Mycobacterium tuberculosis MmpL proteins is controlled by a complex regulatory network, including the TetR family transcriptional regulators Rv3249c and Rv1816. Here we report the crystal structures of these two regulators, revealing dimeric, two-domain molecules with architecture consistent with the TetR family of regulators. Buried extensively within the C-terminal regulatory domains of Rv3249c and Rv1816, we found fortuitous bound ligands, which were identified as palmitic acid (a fatty acid) and isopropyl laurate (a fatty acid ester), respectively. Our results suggest that fatty acids may be the natural ligands of these regulatory proteins. Using fluorescence polarization and electrophoretic mobility shift assays, we demonstrate the recognition of promoter and intragenic regions of multiple mmpL genes by these proteins. Binding of palmitic acid renders these regulators incapable of interacting with their respective operator DNAs, which will result in derepression of the corresponding mmpL genes. Taken together, these experiments provide new perspectives on the regulation of the MmpL family of transporters.
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Affiliation(s)
- Jared A Delmar
- Departments of Physics and Astronomy, Iowa State University, Ames, Iowa 50011
| | - Tsung-Han Chou
- Departments of Physics and Astronomy, Iowa State University, Ames, Iowa 50011
| | - Catherine C Wright
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon 97239
| | - Meredith H Licon
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon 97239
| | - Julia K Doh
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon 97239
| | | | - Nitin Kumar
- Departments of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Hsiang-Ting Lei
- Departments of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Jani Reddy Bolla
- Departments of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Kanagalaghatta R Rajashankar
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois 60439
| | - Chih-Chia Su
- Departments of Physics and Astronomy, Iowa State University, Ames, Iowa 50011
| | - Georgiana E Purdy
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon 97239
| | - Edward W Yu
- Departments of Physics and Astronomy, Iowa State University, Ames, Iowa 50011; Departments of Chemistry, Iowa State University, Ames, Iowa 50011.
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49
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A Duplicated ESAT-6 Region of ESX-5 Is Involved in Protein Export and Virulence of Mycobacteria. Infect Immun 2015; 83:4349-61. [PMID: 26303392 DOI: 10.1128/iai.00827-15] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/19/2015] [Indexed: 11/20/2022] Open
Abstract
The ESX-5 secretion system of Mycobacterium tuberculosis is important for bacterial virulence and for the secretion of the large PE/PPE protein family, whose genes constitute 10% of the M. tuberculosis genome. A four-gene region of the ESX-5 system is duplicated three times in the M. tuberculosis genome, but the functions of these duplicates are unknown. Here we investigated one of these duplicates: the region carrying the esxI, esxJ, ppe15, and pe8 genes (ESX-5a). An ESX-5a deletion mutant in the model system M. marinum background was deficient in the secretion of some members of the PE/PPE family of proteins. Surprisingly, we also identified other proteins that are not members of this family, thus expanding the range of ESX-5 secretion substrates. In addition, we demonstrated that ESX-5a is important for the virulence of M. marinum in the zebrafish model. Furthermore, we showed the role of the M. tuberculosis ESX-5a region in inflammasome activation but not host cell death induction, which is different from the case for the M. tuberculosis ESX-5 system. In conclusion, the ESX-5a region is nonredundant with its ESX-5 paralog and is necessary for secretion of a specific subset of proteins in M. tuberculosis and M. marinum that are important for bacterial virulence of M. marinum. Our findings point to a role for the three ESX-5 duplicate regions in the selection of substrates for secretion via ESX-5, and hence, they provide the basis for a refined model of the molecular mechanism of this type VII secretion system.
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50
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George R, Cavalcante R, Jr CC, Marques E, Waugh JB, Unlap MT. Use of siRNA molecular beacons to detect and attenuate mycobacterial infection in macrophages. World J Exp Med 2015; 5:164-181. [PMID: 26309818 PMCID: PMC4543811 DOI: 10.5493/wjem.v5.i3.164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/05/2015] [Accepted: 06/11/2015] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis is one of the leading infectious diseases plaguing mankind and is mediated by the facultative pathogen, Mycobacterium tuberculosis (MTB). Once the pathogen enters the body, it subverts the host immune defenses and thrives for extended periods of time within the host macrophages in the lung granulomas, a condition called latent tuberculosis (LTB). Persons with LTB are prone to reactivation of the disease when the body’s immunity is compromised. Currently there are no reliable and effective diagnosis and treatment options for LTB, which necessitates new research in this area. The mycobacterial proteins and genes mediating the adaptive responses inside the macrophage is largely yet to be determined. Recently, it has been shown that the mce operon genes are critical for host cell invasion by the mycobacterium and for establishing a persistent infection in both in vitro and in mouse models of tuberculosis. The YrbE and Mce proteins which are encoded by the MTB mce operons display high degrees of homology to the permeases and the surface binding protein of the ABC transports, respectively. Similarities in structure and cell surface location impute a role in cell invasion at cholesterol rich regions and immunomodulation. The mce4 operon is also thought to encode a cholesterol transport system that enables the mycobacterium to derive both energy and carbon from the host membrane lipids and possibly generating virulence mediating metabolites, thus enabling the bacteria in its long term survival within the granuloma. Various deletion mutation studies involving individual or whole mce operon genes have shown to be conferring varying degrees of attenuation of infectivity or at times hypervirulence to the host MTB, with the deletion of mce4A operon gene conferring the greatest degree of attenuation of virulence. Antisense technology using synthetic siRNAs has been used in knocking down genes in bacteria and over the years this has evolved into a powerful tool for elucidating the roles of various genes mediating infectivity and survival in mycobacteria. Molecular beacons are a newer class of antisense RNA tagged with a fluorophore/quencher pair and their use for in vivo detection and knockdown of mRNA is rapidly gaining popularity.
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