1
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Wynn EA, Dide-Agossou C, Reichlen M, Rossmassler K, Al Mubarak R, Reid JJ, Tabor ST, Born SEM, Ransom MR, Davidson RM, Walton KN, Benoit JB, Hoppers A, Loy DE, Bauman AA, Massoudi LM, Dolganov G, Strong M, Nahid P, Voskuil MI, Robertson GT, Moore CM, Walter ND. Transcriptional adaptation of Mycobacterium tuberculosis that survives prolonged multi-drug treatment in mice. mBio 2023; 14:e0236323. [PMID: 37905920 PMCID: PMC10746229 DOI: 10.1128/mbio.02363-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
IMPORTANCE A major reason that curing tuberculosis requires prolonged treatment is that drug exposure changes bacterial phenotypes. The physiologic adaptations of Mycobacterium tuberculosis that survive drug exposure in vivo have been obscure due to low sensitivity of existing methods in drug-treated animals. Using the novel SEARCH-TB RNA-seq platform, we elucidated Mycobacterium tuberculosis phenotypes in mice treated for with the global standard 4-drug regimen and compared them with the effect of the same regimen in vitro. This first view of the transcriptome of the minority Mycobacterium tuberculosis population that withstands treatment in vivo reveals adaptation of a broad range of cellular processes, including a shift in metabolism and cell wall modification. Surprisingly, the change in gene expression induced by treatment in vivo and in vitro was largely similar. This apparent "portability" from in vitro to the mouse provides important new context for in vitro transcriptional analyses that may support early preclinical drug evaluation.
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Affiliation(s)
- Elizabeth A. Wynn
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Department of Biostatistics and Informatics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
| | - Christian Dide-Agossou
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Matthew Reichlen
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Karen Rossmassler
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Reem Al Mubarak
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Justin J. Reid
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Samuel T. Tabor
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Sarah E. M. Born
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Monica R. Ransom
- Division of Hematology, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Rebecca M. Davidson
- Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, USA
| | - Kendra N. Walton
- Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, USA
| | - Jeanne B. Benoit
- Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, USA
| | - Amanda Hoppers
- Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, USA
| | - Dorothy E. Loy
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Allison A. Bauman
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Lisa M. Massoudi
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Gregory Dolganov
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Palo Alto, California, USA
| | - Michael Strong
- Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, USA
| | - Payam Nahid
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary and Critical Care Medicine, University of California San Francisco, San Francisco, California, USA
- UCSF Center for Tuberculosis, University of California San Francisco, San Francisco, California, USA
| | - Martin I. Voskuil
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Gregory T. Robertson
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Camille M. Moore
- Department of Biostatistics and Informatics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Center for Genes, Environment and Health, National Jewish Health, Denver, Colorado, USA
| | - Nicholas D. Walter
- Rocky Mountain Regional VA Medical Center, Aurora, Colorado, USA
- Consortium for Applied Microbial Metrics, Aurora, Colorado, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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2
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Wynn EA, Dide-Agossou C, Reichlen M, Rossmassler K, Al Mubarak R, Reid JJ, Tabor ST, Born SEM, Ransom MR, Davidson RM, Walton KN, Benoit JB, Hoppers A, Bauman AA, Massoudi LM, Dolganov G, Nahid P, Voskuil MI, Robertson GT, Moore CM, Walter ND. Transcriptional adaptation of drug-tolerant Mycobacterium tuberculosis in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.531356. [PMID: 36945388 PMCID: PMC10028792 DOI: 10.1101/2023.03.06.531356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
Transcriptome evaluation of Mycobacterium tuberculosis in the lungs of laboratory animals during long-term treatment has been limited by extremely low abundance of bacterial mRNA relative to eukaryotic RNA. Here we report a targeted amplification RNA sequencing method called SEARCH-TB. After confirming that SEARCH-TB recapitulates conventional RNA-seq in vitro, we applied SEARCH-TB to Mycobacterium tuberculosis-infected BALB/c mice treated for up to 28 days with the global standard isoniazid, rifampin, pyrazinamide, and ethambutol regimen. We compared results in mice with 8-day exposure to the same regimen in vitro. After treatment of mice for 28 days, SEARCH-TB suggested broad suppression of genes associated with bacterial growth, transcription, translation, synthesis of rRNA proteins and immunogenic secretory peptides. Adaptation of drug-stressed Mycobacterium tuberculosis appeared to include a metabolic transition from ATP-maximizing respiration towards lower-efficiency pathways, modification and recycling of cell wall components, large-scale regulatory reprogramming, and reconfiguration of efflux pumps expression. Despite markedly different expression at pre-treatment baseline, murine and in vitro samples had broadly similar transcriptional change during treatment. The differences observed likely indicate the importance of immunity and pharmacokinetics in the mouse. By elucidating the long-term effect of tuberculosis treatment on bacterial cellular processes in vivo, SEARCH-TB represents a highly granular pharmacodynamic monitoring tool with potential to enhance evaluation of new regimens and thereby accelerate progress towards a new generation of more effective tuberculosis treatment.
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Affiliation(s)
- Elizabeth A Wynn
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Department of Biostatistics and Informatics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
| | - Christian Dide-Agossou
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Matthew Reichlen
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Karen Rossmassler
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Reem Al Mubarak
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Justin J Reid
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Samuel T Tabor
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sarah E M Born
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Monica R Ransom
- Division of Hematology, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - Rebecca M Davidson
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Kendra N Walton
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Jeanne B Benoit
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Amanda Hoppers
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Allison A Bauman
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Lisa M Massoudi
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Gregory Dolganov
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Palo Alto, CA, USA
| | - Payam Nahid
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary and Critical Care Medicine, University of California San Francisco, CA, USA
- UCSF Center for Tuberculosis, University of California, San Francisco, CA, USA
| | - Martin I Voskuil
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Gregory T Robertson
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Camille M Moore
- Department of Biostatistics and Informatics, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Nicholas D Walter
- Rocky Mountain Regional VA Medical Center, Aurora, CO, USA
- Consortium for Applied Microbial Metrics, Aurora, CO, USA
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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MadR mediates acyl CoA-dependent regulation of mycolic acid desaturation in mycobacteria. Proc Natl Acad Sci U S A 2022; 119:2111059119. [PMID: 35165190 PMCID: PMC8872791 DOI: 10.1073/pnas.2111059119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2021] [Indexed: 11/20/2022] Open
Abstract
Our studies show that the mycolic acid desaturase regulator (MadR) acts as a molecular switch, controlling the desaturation and biosynthesis of mycolic acids, key lipids of the cell envelopes of mycobacteria. MadR works by a distinct mechanism wherein it binds various acyl-coenzyme As (aceyl-CoAs), but only saturated acyl-CoAs relieve DNA binding and repression. This suggests a unique mechanism that involves sensing of acyl-CoA pools as a checkpoint for coordinating mycolic acid remodeling and biosynthesis in response to cell surface perturbation. Our findings further our understanding of how mycobacteria control cell wall composition in response to stress across various environments ranging from soil to an intracellular niche in infected macrophages, with implications for understanding strategies for pathogenesis in the tubercle bacillus. Mycobacterium tuberculosis has a lipid-rich cell envelope that is remodeled throughout infection to enable adaptation within the host. Few transcriptional regulators have been characterized that coordinate synthesis of mycolic acids, the major cell wall lipids of mycobacteria. Here, we show that the mycolic acid desaturase regulator (MadR), a transcriptional repressor of the mycolate desaturase genes desA1 and desA2, controls mycolic acid desaturation and biosynthesis in response to cell envelope stress. A madR-null mutant of M. smegmatis exhibited traits of an impaired cell wall with an altered outer mycomembrane, accumulation of a desaturated α-mycolate, susceptibility to antimycobacterials, and cell surface disruption. Transcriptomic profiling showed that enriched lipid metabolism genes that were significantly down-regulated upon madR deletion included acyl-coenzyme A (aceyl-CoA) dehydrogenases, implicating it in the indirect control of β-oxidation pathways. Electromobility shift assays and binding affinities suggest a unique acyl-CoA pool–sensing mechanism, whereby MadR is able to bind a range of acyl-CoAs, including those with unsaturated as well as saturated acyl chains. MadR repression of desA1/desA2 is relieved upon binding of saturated acyl-CoAs of chain length C16 to C24, while no impact is observed upon binding of shorter chain and unsaturated acyl-CoAs. We propose this mechanism of regulation as distinct to other mycolic acid and fatty acid synthesis regulators and place MadR as the key regulatory checkpoint that coordinates mycolic acid remodeling during infection in response to host-derived cell surface perturbation.
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4
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Matilla MA, Velando F, Martín-Mora D, Monteagudo-Cascales E, Krell T. A catalogue of signal molecules that interact with sensor kinases, chemoreceptors and transcriptional regulators. FEMS Microbiol Rev 2021; 46:6356564. [PMID: 34424339 DOI: 10.1093/femsre/fuab043] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022] Open
Abstract
Bacteria have evolved many different signal transduction systems that sense signals and generate a variety of responses. Generally, most abundant are transcriptional regulators, sensor histidine kinases and chemoreceptors. Typically, these systems recognize their signal molecules with dedicated ligand-binding domains (LBDs), which, in turn, generate a molecular stimulus that modulates the activity of the output module. There are an enormous number of different LBDs that recognize a similarly diverse set of signals. To give a global perspective of the signals that interact with transcriptional regulators, sensor kinases and chemoreceptors, we manually retrieved information on the protein-ligand interaction from about 1,200 publications and 3D structures. The resulting 811 proteins were classified according to the Pfam family into 127 groups. These data permit a delineation of the signal profiles of individual LBD families as well as distinguishing between families that recognize signals in a promiscuous manner and those that possess a well-defined ligand range. A major bottleneck in the field is the fact that the signal input of many signaling systems is unknown. The signal repertoire reported here will help the scientific community design experimental strategies to identify the signaling molecules for uncharacterised sensor proteins.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Félix Velando
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - David Martín-Mora
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Elizabet Monteagudo-Cascales
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
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5
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Dong W, Nie X, Zhu H, Liu Q, Shi K, You L, Zhang Y, Fan H, Yan B, Niu C, Lyu LD, Zhao GP, Yang C. Mycobacterial fatty acid catabolism is repressed by FdmR to sustain lipogenesis and virulence. Proc Natl Acad Sci U S A 2021; 118:e2019305118. [PMID: 33853942 PMCID: PMC8072231 DOI: 10.1073/pnas.2019305118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Host-derived fatty acids are an important carbon source for pathogenic mycobacteria during infection. How mycobacterial cells regulate the catabolism of fatty acids to serve the pathogenicity, however, remains unknown. Here, we identified a TetR-family transcriptional factor, FdmR, as the key regulator of fatty acid catabolism in the pathogen Mycobacterium marinum by combining use of transcriptomics, chromatin immunoprecipitation followed by sequencing, dynamic 13C-based flux analysis, metabolomics, and lipidomics. An M. marinum mutant deficient in FdmR was severely attenuated in zebrafish larvae and adult zebrafish. The mutant showed defective growth but high substrate consumption on fatty acids. FdmR was identified as a long-chain acyl-coenzyme A (acyl-CoA)-responsive repressor of genes involved in fatty acid degradation and modification. We demonstrated that FdmR functions as a valve to direct the flux of exogenously derived fatty acids away from β-oxidation toward lipid biosynthesis, thereby avoiding the overactive catabolism and accumulation of biologically toxic intermediates. Moreover, we found that FdmR suppresses degradation of long-chain acyl-CoAs endogenously synthesized through the type I fatty acid synthase. By modulating the supply of long-chain acyl-CoAs for lipogenesis, FdmR controls the abundance and chain length of virulence-associated lipids and mycolates and plays an important role in the impermeability of the cell envelope. These results reveal that despite the fact that host-derived fatty acids are used as an important carbon source, overactive catabolism of fatty acids is detrimental to mycobacterial cell growth and pathogenicity. This study thus presents FdmR as a potentially attractive target for chemotherapy.
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Affiliation(s)
- Wenyue Dong
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoqun Nie
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
| | - Hong Zhu
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
| | - Qingyun Liu
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA 02115
| | - Kunxiong Shi
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
| | - Linlin You
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Zhang
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
| | - Hongyan Fan
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
| | - Bo Yan
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
| | - Chen Niu
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China;
| | - Liang-Dong Lyu
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China;
| | - Guo-Ping Zhao
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China
- Key Laboratory of Medical Molecular Virology of the Ministry of Education/National Health Commission/Chinese Academy of Medical Sciences (MOE/NHC/CAMS), School of Basic Medical Sciences, Department of Microbiology, School of Life Sciences, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200000, China
- Bio-Med Big Data Center, CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chen Yang
- CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China;
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Laval T, Chaumont L, Demangel C. Not too fat to fight: The emerging role of macrophage fatty acid metabolism in immunity to Mycobacterium tuberculosis. Immunol Rev 2021; 301:84-97. [PMID: 33559209 DOI: 10.1111/imr.12952] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/23/2022]
Abstract
While the existence of a special relationship between Mycobacterium tuberculosis (Mtb) and host lipids has long been known, it remains a challenging enigma. It was clearly established that Mtb requires host fatty acids (FAs) and cholesterol to produce energy, build its distinctive lipid-rich cell wall, and produce lipid virulence factors. It was also observed that in infected hosts, Mtb constantly resides in a FA-rich environment that the pathogen contributes to generate by inducing a lipid-laden "foamy" phenotype in host macrophages. These observations and the proximity between lipid droplets and phagosomes containing bacteria within infected macrophages gave rise to the hypothesis that Mtb reprograms host cell lipid metabolism to ensure a continuous supply of essential nutrients and its long-term persistence in vivo. However, recent studies question this principle by indicating that in Mtb-infected macrophages, lipid droplet formation prevents bacterial acquisition of host FAs while supporting the production of FA-derived protective lipid mediators. Further, in vivo investigations reveal discrete macrophage phenotypes linking the FA metabolisms of host cell and intracellular pathogen. Notably, FA storage within lipid droplets characterizes both macrophages controlling Mtb infection and dormant intracellular Mtb. In this review, we integrate findings from immunological and microbiological studies illustrating the new concept that cytoplasmic accumulation of FAs is a metabolic adaptation of macrophages to Mtb infection, which potentiates their antimycobacterial responses and forces the intracellular pathogen to shift into fat-saving, survival mode.
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Affiliation(s)
- Thomas Laval
- Immunobiology of Infection Unit, Institut Pasteur, INSERM U1221, Paris, France.,Université de Paris, Sorbonne Paris Cité, Paris, France
| | - Lise Chaumont
- Immunobiology of Infection Unit, Institut Pasteur, INSERM U1221, Paris, France
| | - Caroline Demangel
- Immunobiology of Infection Unit, Institut Pasteur, INSERM U1221, Paris, France
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7
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Mondino S, Vázquez CL, Cabruja M, Sala C, Cazenave-Gassiot A, Blanco FC, Wenk MR, Bigi F, Cole ST, Gramajo H, Gago G. FasR Regulates Fatty Acid Biosynthesis and Is Essential for Virulence of Mycobacterium tuberculosis. Front Microbiol 2020; 11:586285. [PMID: 33193236 PMCID: PMC7652896 DOI: 10.3389/fmicb.2020.586285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/22/2020] [Indexed: 01/13/2023] Open
Abstract
Mycobacterium tuberculosis, the etiologic agent of human tuberculosis, is the world's leading cause of death from an infectious disease. One of the main features of this pathogen is the complex and dynamic lipid composition of the cell envelope, which adapts to the variable host environment and defines the fate of infection by actively interacting with and modulating immune responses. However, while much has been learned about the enzymes of the numerous lipid pathways, little knowledge is available regarding the proteins and metabolic signals regulating lipid metabolism during M. tuberculosis infection. In this work, we constructed and characterized a FasR-deficient mutant in M. tuberculosis and demonstrated that FasR positively regulates fas and acpS expression. Lipidomic analysis of the wild type and mutant strains revealed complete rearrangement of most lipid components of the cell envelope, with phospholipids, mycolic acids, sulfolipids, and phthiocerol dimycocerosates relative abundance severely altered. As a consequence, replication of the mutant strain was impaired in macrophages leading to reduced virulence in a mouse model of infection. Moreover, we show that the fasR mutant resides in acidified cellular compartments, suggesting that the lipid perturbation caused by the mutation prevented M. tuberculosis inhibition of phagolysosome maturation. This study identified FasR as a novel factor involved in regulation of mycobacterial virulence and provides evidence for the essential role that modulation of lipid homeostasis plays in the outcome of M. tuberculosis infection.
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Affiliation(s)
- Sonia Mondino
- Laboratory of Physiology and Genetics of Actinomycetes, Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Universidad Nacional de Rosario, Rosario, Argentina
| | | | - Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Universidad Nacional de Rosario, Rosario, Argentina
| | - Claudia Sala
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Amaury Cazenave-Gassiot
- Singapore Lipidomics Incubator (SLING), Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Markus R. Wenk
- Singapore Lipidomics Incubator (SLING), Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Fabiana Bigi
- Instituto de Biotecnología-IABIMO (INTA-CONICET), Hurlingham, Argentina
| | - Stewart T. Cole
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Universidad Nacional de Rosario, Rosario, Argentina
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Facultad de Ciencias Bioquímicas y Farmacéuticas, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Universidad Nacional de Rosario, Rosario, Argentina
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8
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Xu H, Su Z, Li W, Deng Y, He ZG. MmbR, a master transcription regulator that controls fatty acid β-oxidation genes in Mycolicibacterium smegmatis. Environ Microbiol 2020; 23:1096-1114. [PMID: 32985741 DOI: 10.1111/1462-2920.15249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/23/2020] [Indexed: 11/29/2022]
Abstract
An unusually high lipid content and a complex lipid profile are the most distinctive features of the mycobacterial cell envelope. However, our understanding of the regulatory mechanism underlying mycobacterial lipid metabolism is limited, and the major regulators responsible for lipid homeostasis remain to be characterized. Here, we identified MmbR as a novel master regulator that is essential for maintaining lipid homeostasis in Mycolicibacterium smegmatis. We found that MmbR controls fatty acid β-oxidation and modulates biofilm formation in Mycolicibacterium smegmatis. Although MmbR possesses the properties of nucleoid-associated proteins, it acts as a TetR-like transcription factor, directly regulating and intensively repressing the expression of a group of core genes involved in fatty acid β-oxidation. Furthermore, both long-chain acyl-Coenzyme A and fatty acids appear to regulate the signal molecules modulated by MmbR. The deletion of mmbR led to a significant reduction in intracellular fatty acid content and a decrease in the relative lipid composition of the biofilm. The lack of mmbR led to morphological changes in the mycobacterial colony, defects in biofilm formation and enhanced sensitivity to anti-tuberculosis drugs. Our study is the first to establish a link between the transcriptional regulation of fatty acid β-oxidation genes and lipid homeostasis in mycobacteria.
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Affiliation(s)
- Hui Xu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhi Su
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Weihui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yimin Deng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zheng-Guo He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
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9
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Lara J, Diacovich L, Trajtenberg F, Larrieux N, Malchiodi EL, Fernández MM, Gago G, Gramajo H, Buschiazzo A. Mycobacterium tuberculosis FasR senses long fatty acyl-CoA through a tunnel and a hydrophobic transmission spine. Nat Commun 2020; 11:3703. [PMID: 32710080 PMCID: PMC7382501 DOI: 10.1038/s41467-020-17504-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 06/30/2020] [Indexed: 11/09/2022] Open
Abstract
Mycobacterium tuberculosis is a pathogen with a unique cell envelope including very long fatty acids, implicated in bacterial resistance and host immune modulation. FasR is a TetR-like transcriptional activator that plays a central role in sensing mycobacterial long-chain fatty acids and regulating lipid biosynthesis. Here we disclose crystal structures of M. tuberculosis FasR in complex with acyl effector ligands and with DNA, uncovering its molecular sensory and switching mechanisms. A long tunnel traverses the entire effector-binding domain, enabling long fatty acyl effectors to bind. Only when the tunnel is entirely occupied, the protein dimer adopts a rigid configuration with its DNA-binding domains in an open state, leading to DNA dissociation. The protein-folding hydrophobic core connects the two domains, and is completed into a continuous spine when the effector binds. Such a transmission spine is conserved in a large number of TetR-like regulators, offering insight into effector-triggered allosteric functional control. FasR is a TetR-like transcriptional activator that plays a central role in sensing mycobacterial long-chain fatty acids and regulating lipid biosynthesis in Mycobacterium tuberculosis. Here authors present crystal structures of M. tuberculosis FasR in complex with acyl effector ligands and with DNA, uncovering its molecular sensory and switching mechanisms.
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Affiliation(s)
- Julia Lara
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, 2000, Argentina
| | - Lautaro Diacovich
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, 2000, Argentina.,Plataforma Argentina de Biología Estructural y Metabolómica (PLABEM), Rosario, 2000, Argentina
| | - Felipe Trajtenberg
- Laboratory of Molecular and Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, 11400, Uruguay
| | - Nicole Larrieux
- Laboratory of Molecular and Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, 11400, Uruguay
| | - Emilio L Malchiodi
- Instituto de Estudios de la Inmunidad Humoral (IDEHU/CONICET-UBA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, 1113, Argentina
| | - Marisa M Fernández
- Instituto de Estudios de la Inmunidad Humoral (IDEHU/CONICET-UBA), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, 1113, Argentina
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, 2000, Argentina
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, 2000, Argentina.
| | - Alejandro Buschiazzo
- Laboratory of Molecular and Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, 11400, Uruguay. .,Integrative Microbiology of Zoonotic Agents, International Joint Research Unit, Department of Microbiology, Institut Pasteur, Paris, 75724, Cedex 15, France.
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10
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Li Y, Li W, Xie Z, Xu H, He ZG. MpbR, an essential transcriptional factor for Mycobacterium tuberculosis survival in the host, modulates PIM biosynthesis and reduces innate immune responses. J Genet Genomics 2019; 46:575-589. [DOI: 10.1016/j.jgg.2019.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 01/08/2023]
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11
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Transcriptional Regulator AcrR Increases Ethanol Tolerance through Regulation of Fatty Acid Synthesis in Lactobacillus plantarum. Appl Environ Microbiol 2019; 85:AEM.01690-19. [PMID: 31519657 DOI: 10.1128/aem.01690-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/11/2019] [Indexed: 01/24/2023] Open
Abstract
Lactobacillus plantarum is a versatile bacterium with significant adaptability to harsh habitats containing excessive ethanol concentrations. It was found that the L. plantarum NF92-TetR/AcrR family regulator, AcrR, significantly enhanced the growth rate of this lactic acid bacterium in the presence of ethanol. Through screening 172 ethanol-resistant related genes by electrophoretic mobility shift and quantitative reverse transcription-PCR (RT-qPCR) assays, six genes were identified to be regulated by AcrR under ethanol stress. Among these was a gene coding for a 3-hydroxyacyl-ACP dehydratase (fabZ1) regulated by AcrR under ethanol stress. AcrR regulated fabZ1 under ethanol stress by binding to its promoter, P fabZ1 DNase I footprinting analysis indicated that there were two specific AcrR binding sites on P fabZ1 RT-PCR results showed fabZ1 could cotranscribe with its downstream 12 genes and conform a fatty acid de novo biosynthesis (fab) gene cluster under the control of P fabZ1 Both RT-qPCR of the fab gene cluster in acrR knockout and overexpression strains and fatty acid methyl ester analysis of the acrR knockout strain showed that AcrR could promote fatty acid synthesis in L. plantarum NF92. Membrane fluorescence anisotropy analysis of acrR knockout and overexpression strains showed that AcrR could increase membrane fluidity under ethanol stress. Thus, AcrR could regulate fatty acid synthesis and membrane fluidity to promote the adaption of L. plantarum NF92 to a high ethanol concentration.IMPORTANCE Ethanol tolerance is essential for L. plantarum strains living in substances with more than 9% ethanol, such as wine and beer. The details regarding how L. plantarum adapts to ethanol are still lacking. This study demonstrates that AcrR regulates the de novo synthesis of fatty acids in L. plantarum adapting to toxic levels of ethanol. We also identified the ability of the TetR/AcrR family regulator to bind to the fatty acid biosynthesis gene promoter, P fabZ1 , in L. plantarum and defined the binding sites. This finding facilitates the induction of the adaptation of L. plantarum strains to ethanol for food fermentation applications.
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12
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Peterson EJ, Bailo R, Rothchild AC, Arrieta-Ortiz ML, Kaur A, Pan M, Mai D, Abidi AA, Cooper C, Aderem A, Bhatt A, Baliga NS. Path-seq identifies an essential mycolate remodeling program for mycobacterial host adaptation. Mol Syst Biol 2019; 15:e8584. [PMID: 30833303 PMCID: PMC6398593 DOI: 10.15252/msb.20188584] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 11/23/2022] Open
Abstract
The success of Mycobacterium tuberculosis (MTB) stems from its ability to remain hidden from the immune system within macrophages. Here, we report a new technology (Path-seq) to sequence miniscule amounts of MTB transcripts within up to million-fold excess host RNA Using Path-seq and regulatory network analyses, we have discovered a novel transcriptional program for in vivo mycobacterial cell wall remodeling when the pathogen infects alveolar macrophages in mice. We have discovered that MadR transcriptionally modulates two mycolic acid desaturases desA1/desA2 to initially promote cell wall remodeling upon in vitro macrophage infection and, subsequently, reduces mycolate biosynthesis upon entering dormancy. We demonstrate that disrupting MadR program is lethal to diverse mycobacteria making this evolutionarily conserved regulator a prime antitubercular target for both early and late stages of infection.
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Affiliation(s)
| | - Rebeca Bailo
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Alissa C Rothchild
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | | | | | - Min Pan
- Institute for Systems Biology, Seattle, WA, USA
| | - Dat Mai
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | | | - Charlotte Cooper
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Alan Aderem
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - Nitin S Baliga
- Institute for Systems Biology, Seattle, WA, USA
- Molecular and Cellular Biology Program, Departments of Microbiology and Biology, University of Washington, Seattle, WA, USA
- Lawrence Berkeley National Laboratories, Berkeley, CA, USA
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13
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Baron S, Peleg Y, Grunwald J, Morgenstern D, Elad N, Peretz M, Albeck S, Levin Y, Welch JT, DeWeerd KA, Schwarz A, Burstein Y, Diskin R, Shakked Z, Zimhony O. Expression of a recombinant, 4'-Phosphopantetheinylated, active M. tuberculosis fatty acid synthase I in E. coli. PLoS One 2018; 13:e0204457. [PMID: 30248156 PMCID: PMC6152951 DOI: 10.1371/journal.pone.0204457] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 09/07/2018] [Indexed: 11/18/2022] Open
Abstract
Background Fatty acid synthase 1 (FAS I) from Mycobacterium tuberculosis (Mtb) is an essential protein and a promising drug target. FAS I is a multi-functional, multi-domain protein that is organized as a large (1.9 MDa) homohexameric complex. Acyl intermediates produced during fatty acid elongation are attached covalently to an acyl carrier protein (ACP) domain. This domain is activated by the transfer of a 4'-Phosphopantetheine (4'-PP, also termed P-pant) group from CoA to ACP catalyzed by a 4'-PP transferase, termed acyl carrier protein synthase (AcpS). Methods In order to obtain an activated FAS I in E. coli, we transformed E. coli with tagged Mtb fas1 and acpS genes encoded by a separate plasmid. We induced the expression of Mtb FAS I following induction of AcpS expression. FAS I was purified by Strep-Tactin affinity chromatography. Results Activation of Mtb FAS I was confirmed by the identification of a bound P-pant group on serine at position 1808 by mass spectrometry. The purified FAS I displayed biochemical activity shown by spectrophotometric analysis of NADPH oxidation and by CoA production, using the Ellman reaction. The purified Mtb FAS I forms a hexameric complex shown by negative staining and cryo-EM. Conclusion Purified hexameric and active Mtb FAS I is required for binding and drug inhibition studies and for structure-function analysis of this enzyme. This relatively simple and short procedure for Mtb FAS I production should facilitate studies of this enzyme.
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Affiliation(s)
- Szilvia Baron
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yoav Peleg
- Structural Proteomics Unit (SPU), Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Jacob Grunwald
- Structural Proteomics Unit (SPU), Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - David Morgenstern
- De Botton Institute for Protein Profiling, Weizmann Institute of Science, Rehovot, Israel
| | - Nadav Elad
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Moshe Peretz
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Shira Albeck
- Structural Proteomics Unit (SPU), Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Yishai Levin
- De Botton Institute for Protein Profiling, Weizmann Institute of Science, Rehovot, Israel
| | - John T. Welch
- Department of Chemistry, College of Arts and Sciences University at Albany, New York, United States of America
| | - Kim A. DeWeerd
- Molecular Core Facility College of Arts and Sciences University at Albany, New York, United States of America
| | - Alon Schwarz
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yigal Burstein
- Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Ron Diskin
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Zippora Shakked
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Oren Zimhony
- Kaplan Medical Center, Rehovot, affiliated to the School of Medicine, Hebrew University and Hadassah, Jerusalem, Israel
- * E-mail: ,
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14
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Adipocyte Model of Mycobacterium tuberculosis Infection Reveals Differential Availability of Iron to Bacilli in the Lipid-Rich Caseous Environment. Infect Immun 2018; 86:IAI.00041-18. [PMID: 29632245 PMCID: PMC5964510 DOI: 10.1128/iai.00041-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 03/28/2018] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis, a successful human pathogen, utilizes multiple carbon sources from the host but adapts to a fatty-acid-rich environment in vivo. We sought to delineate the physiologic response of M. tuberculosis to a lipid-rich environment by using differentiated adipocytes as a model system. Global transcriptome profiling based on RNA sequencing was performed for bacilli from infected adipocytes and preadipocytes. Genes involved in de novo fatty acid synthesis were downregulated, while those predicted to be involved in triglyceride biosynthesis were upregulated, in bacilli isolated from adipocytes, indicating reliance on host-derived fatty acids. Transcription factor network analysis indicated suppression of IdeR-regulated genes, suggesting decreased iron uptake by M. tuberculosis in the adipocyte model. This suppression of iron uptake coincided with higher ferritin and iron levels in adipocytes than in preadipocytes. In accord with the role of iron in mediating oxidative stress, we observed upregulation of genes involved in mitigating oxidative stress in M. tuberculosis isolated from adipocytes. We provide evidence that oleic acid, a major host-derived fatty acid, helps reduce the bacterial cytoplasm, thereby providing a safe haven for an M. tuberculosis mutant that is sensitive to iron-mediated oxidative stress. Via an independent mechanism, host ferritin is also able to rescue the growth of this mutant. Our work highlights the inherent synergy between macronutrients and micronutrients of the host environment that converge to provide resilience to the pathogen. This complex synergy afforded by the adipocyte model of infection will aid in the identification of genes required by M. tuberculosis in a caseous host environment.
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15
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Tsai YT, Salzman V, Cabruja M, Gago G, Gramajo H. Role of long-chain acyl-CoAs in the regulation of mycolic acid biosynthesis in mycobacteria. Open Biol 2018; 7:rsob.170087. [PMID: 28724694 PMCID: PMC5541348 DOI: 10.1098/rsob.170087] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/26/2017] [Indexed: 12/16/2022] Open
Abstract
One of the dominant features of the biology of Mycobacterium tuberculosis, and other mycobacteria, is the mycobacterial cell envelope with its exceptional complex composition. Mycolic acids are major and very specific components of the cell envelope and play a key role in its architecture and impermeability. Biosynthesis of mycolic acid (MA) precursors requires two types of fatty acid synthases, FAS I and FAS II, which should work in concert in order to keep lipid homeostasis tightly regulated. Both FAS systems are regulated at their transcriptional level by specific regulatory proteins. FasR regulates components of the FAS I system, whereas MabR and FadR regulate components of the FAS II system. In this article, by constructing a tight mabR conditional mutant in Mycobacterium smegmatis mc2155, we demonstrated that sub-physiological levels of MabR lead to a downregulation of the fasII genes, inferring that this protein is a transcriptional activator of the FAS II system. In vivo labelling experiments and lipidomic studies carried out in the wild-type and the mabR conditional mutant demonstrated that under conditions of reduced levels of MabR, there is a clear inhibition of biosynthesis of MAs, with a concomitant change in their relative composition, and of other MA-containing molecules. These studies also demonstrated a change in the phospholipid composition of the membrane of the mutant strain, with a significant increase of phosphatidylinositol. Gel shift assays carried out with MabR and PfasII as a probe in the presence of different chain-length acyl-CoAs strongly suggest that molecules longer than C18 can be sensed by MabR to modulate its affinity for the operator sequences that it recognizes, and in that way switch on or off the MabR-dependent promoter. Finally, we demonstrated the direct role of MabR in the upregulation of the fasII operon genes after isoniazid treatment.
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Affiliation(s)
- Yi Ting Tsai
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Valentina Salzman
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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16
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Gago G, Diacovich L, Gramajo H. Lipid metabolism and its implication in mycobacteria-host interaction. Curr Opin Microbiol 2018; 41:36-42. [PMID: 29190491 PMCID: PMC5862736 DOI: 10.1016/j.mib.2017.11.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/16/2022]
Abstract
The complex lipids present in the cell wall of Mycobacterium tuberculosis (Mtb) act as major effector molecules that actively interact with the host, modulating its metabolism and stimulating the immune response, which in turn affects the physiology of both, the host cell and the bacilli. Lipids from the host are also nutrient sources for the pathogen and define the fate of the infection by modulating lipid homeostasis. Although new technologies and experimental models of infection have greatly helped understanding the different aspects of the host-pathogen interactions at the lipid level, the impact of this interaction in the Mtb lipid regulation is still incipient, mainly because of the low background knowledge in this area of research.
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Affiliation(s)
- Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Lautaro Diacovich
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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17
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Cabruja M, Mondino S, Tsai YT, Lara J, Gramajo H, Gago G. A conditional mutant of the fatty acid synthase unveils unexpected cross talks in mycobacterial lipid metabolism. Open Biol 2017; 7:rsob.160277. [PMID: 28228470 PMCID: PMC5356441 DOI: 10.1098/rsob.160277] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/25/2017] [Indexed: 01/02/2023] Open
Abstract
Unlike most bacteria, mycobacteria rely on the multi-domain enzyme eukaryote-like fatty acid synthase I (FAS I) to make fatty acids de novo. These metabolites are precursors of the biosynthesis of most of the lipids present both in the complex mycobacteria cell wall and in the storage lipids inside the cell. In order to study the role of the type I FAS system in Mycobacterium lipid metabolism in vivo, we constructed a conditional mutant in the fas-acpS operon of Mycobacterium smegmatis and analysed in detail the impact of reduced de novo fatty acid biosynthesis on the global architecture of the cell envelope. As expected, the mutant exhibited growth defect in the non-permissive condition that correlated well with the lower expression of fas-acpS and the concomitant reduction of FAS I, confirming that FAS I is essential for survival. The reduction observed in FAS I provoked an accumulation of its substrates, acetyl-CoA and malonyl-CoA, and a strong reduction of C12 to C18 acyl-CoAs, but not of long-chain acyl-CoAs (C19 to C24). The most intriguing result was the ability of the mutant to keep synthesizing mycolic acids when fatty acid biosynthesis was impaired. A detailed comparative lipidomic analysis showed that although reduced FAS I levels had a strong impact on fatty acid and phospholipid biosynthesis, mycolic acids were still being synthesized in the mutant, although with a different relative species distribution. However, when triacylglycerol degradation was inhibited, mycolic acid biosynthesis was significantly reduced, suggesting that storage lipids could be an intracellular reservoir of fatty acids for the biosynthesis of complex lipids in mycobacteria. Understanding the interaction between FAS I and the metabolic pathways that rely on FAS I products is a key step to better understand how lipid homeostasis is regulated in this microorganism and how this regulation could play a role during infection in pathogenic mycobacteria.
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Affiliation(s)
- Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Sonia Mondino
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Yi Ting Tsai
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Julia Lara
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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18
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Toyoda K, Inui M. Extracytoplasmic function sigma factor σDconfers resistance to environmental stress by enhancing mycolate synthesis and modifying peptidoglycan structures inCorynebacterium glutamicum. Mol Microbiol 2017; 107:312-329. [DOI: 10.1111/mmi.13883] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Koichi Toyoda
- Research institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawa; Kyoto 619-0292 Japan
| | - Masayuki Inui
- Research institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawa; Kyoto 619-0292 Japan
- Graduate School of Biological Sciences; Nara Institute of Science and Technology, 8916-5; Takayama, Ikoma, Nara 630-0101 Japan
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19
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Boldrin F, Degiacomi G, Serafini A, Kolly GS, Ventura M, Sala C, Provvedi R, Palù G, Cole ST, Manganelli R. Promoter mutagenesis for fine-tuning expression of essential genes in Mycobacterium tuberculosis. Microb Biotechnol 2017; 11:238-247. [PMID: 29076636 PMCID: PMC5743821 DOI: 10.1111/1751-7915.12875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 09/05/2017] [Accepted: 09/25/2017] [Indexed: 02/04/2023] Open
Abstract
A range of regulated gene expression systems has been developed for mycobacteria in the last few years to facilitate the study of essential genes, validate novel drug targets and evaluate their vulnerability. Among these, the TetR/Pip-OFF repressible promoter system was successfully used in several mycobacterial species both in vitro and in vivo. In the first version of the system, the repressible promoter was Pptr , a strong Pip-repressible promoter of Streptomyces pristinaespiralis, which might hamper effective downregulation of genes with a low basal expression level. Here, we report an enhanced system that allows more effective control of genes expressed at low level. To this end, we subjected Pptr to targeted mutagenesis and produced 16 different promoters with different strength. Three of them, weaker than the wild-type promoter, were selected and characterized showing that they can indeed improve the performances of TetR/Pip-OFF repressible system both in vitro and in vivo increasing its stringency. Finally, we used these promoters to construct a series of bacterial biosensors with different sensitivity to DprE1 inhibitors and developed a whole-cell screening assay to identify inhibitors of this enzyme.
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Affiliation(s)
- Francesca Boldrin
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Giulia Degiacomi
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Agnese Serafini
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Gaëlle S Kolly
- Ecole Polytechnique Fédérale de Lausanne, Global Health Institute, Station 19, 1015, Lausanne, Switzerland
| | - Marcello Ventura
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Claudia Sala
- Ecole Polytechnique Fédérale de Lausanne, Global Health Institute, Station 19, 1015, Lausanne, Switzerland
| | - Roberta Provvedi
- Department of Biology, University of Padova, 35121, Padova, Italy
| | - Giorgio Palù
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Stewart T Cole
- Ecole Polytechnique Fédérale de Lausanne, Global Health Institute, Station 19, 1015, Lausanne, Switzerland
| | - Riccardo Manganelli
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
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Quémard A. New Insights into the Mycolate-Containing Compound Biosynthesis and Transport in Mycobacteria. Trends Microbiol 2016; 24:725-738. [DOI: 10.1016/j.tim.2016.04.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/14/2016] [Accepted: 04/29/2016] [Indexed: 12/15/2022]
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Cabruja M, Lyonnet BB, Millán G, Gramajo H, Gago G. Analysis of coenzyme A activated compounds in actinomycetes. Appl Microbiol Biotechnol 2016; 100:7239-48. [PMID: 27270600 DOI: 10.1007/s00253-016-7635-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/06/2016] [Accepted: 05/14/2016] [Indexed: 10/21/2022]
Abstract
Acyl-CoAs are crucial compounds involved in essential metabolic pathways such as the Krebs cycle and lipid, carbohydrate, and amino acid metabolisms, and they are also key signal molecules involved in the transcriptional regulation of lipid biosynthesis in many organisms. In this study, we took advantage of the high selectivity of mass spectrometry and developed an ion-pairing reverse-phase high-pressure liquid chromatography electrospray ionization high-resolution mass spectrometry (IP-RP-HPLC/ESI-HRMS) method to carry on a comprehensive analytical determination of the wide range of fatty acyl-CoAs present in actinomycetes. The advantage of using a QTOF spectrometer resides in the excellent mass accuracy over a wide dynamic range and measurements of the true isotope pattern that can be used for molecular formula elucidation of unknown analytes. As a proof of concept, we used this assay to determine the composition of the fatty acyl-CoA pools in Mycobacterium, Streptomyces, and Corynebacterium species, revealing an extraordinary difference in fatty acyl-CoA amounts and species distribution between the three genera and between the two species of mycobacteria analyzed, including the presence of different chain-length carboxy-acyl-CoAs, key substrates of mycolic acid biosynthesis. The method was also used to analyze the impact of two fatty acid synthase inhibitors on the acyl-CoA profile of Mycobacterium smegmatis, which showed some unexpected low levels of C24 acyl-CoAs in the isoniazid-treated cells. This robust, sensitive, and reliable method should be broadly applicable in the studies of the wide range of bacteria metabolisms in which acyl-CoA molecules participate.
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Affiliation(s)
- Matías Cabruja
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina
| | - Bernardo Bazet Lyonnet
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina
| | - Gustavo Millán
- Laboratory of Mass Spectrometry, Centro Científico Tecnológico Rosario, CONICET, Rosario, Argentina
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina.
| | - Gabriela Gago
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, (2000), Argentina.
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22
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Mycobacterial Metabolic Syndrome: LprG and Rv1410 Regulate Triacylglyceride Levels, Growth Rate and Virulence in Mycobacterium tuberculosis. PLoS Pathog 2016; 12:e1005351. [PMID: 26751071 PMCID: PMC4709180 DOI: 10.1371/journal.ppat.1005351] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 11/30/2015] [Indexed: 11/19/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) mutants lacking rv1411c, which encodes the lipoprotein LprG, and rv1410c, which encodes a putative efflux pump, are dramatically attenuated for growth in mice. Here we show that loss of LprG-Rv1410 in Mtb leads to intracellular triacylglyceride (TAG) accumulation, and overexpression of the locus increases the levels of TAG in the culture medium, demonstrating a role of this locus in TAG transport. LprG binds TAG within a large hydrophobic cleft and is sufficient to transfer TAG from donor to acceptor membranes. Further, LprG-Rv1410 is critical for broadly regulating bacterial growth and metabolism in vitro during carbon restriction and in vivo during infection of mice. The growth defect in mice is due to disrupted bacterial metabolism and occurs independently of key immune regulators. The in vivo essentiality of this locus suggests that this export system and other regulators of metabolism should be considered as targets for novel therapeutics. Of the estimated 2 billion people worldwide currently infected with Mycobacterium tuberculosis (Mtb), surprisingly few go on to develop active tuberculosis (TB) disease. The vast majority, 95 percent, of infected individuals develop latent TB, remaining infected but without disease. Despite its importance in global health, the question of what determines whether an infected individual will develop active or latent TB remains largely unanswered. Changes in how Mtb grows in response to stressors presented by the host environment likely play an important role in this process. In particular, the manifold ways in which Mtb synthesizes, degrades, and transports lipids dictates its growth in an infected host. Here, we show that lipid transport is an important function of two TB genes known to be required for Mtb’s ability to cause disease in the mouse model of infection. Using a variety of genetic and biochemical techniques, we found that the products of these genes prevent the cytosolic accumulation of a lipid associated with non-growing Mtb under the metabolic conditions it encounters during infection. Our results indicate an important role for the metabolism of Mtb in its ability to orchestrate a productive infection and cause disease.
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Evolution of Mycolic Acid Biosynthesis Genes and Their Regulation during Starvation in Mycobacterium tuberculosis. J Bacteriol 2015; 197:3797-811. [PMID: 26416833 DOI: 10.1128/jb.00433-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 09/22/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Mycobacterium tuberculosis, the etiological agent of tuberculosis, is a Gram-positive bacterium with a unique cell envelope composed of an essential outer membrane. Mycolic acids, which are very-long-chain (up to C100) fatty acids, are the major components of this mycomembrane. The enzymatic pathways involved in the biosynthesis and transport of mycolates are fairly well documented and are the targets of the major antituberculous drugs. In contrast, only fragmented information is available on the expression and regulation of the biosynthesis genes. In this study, we report that the hadA, hadB, and hadC genes, which code for the mycolate biosynthesis dehydratase enzymes, are coexpressed with three genes that encode proteins of the translational apparatus. Consistent with the well-established control of the translation potential by nutrient availability, starvation leads to downregulation of the hadABC genes along with most of the genes required for the synthesis, modification, and transport of mycolates. The downregulation of a subset of the biosynthesis genes is partially dependent on RelMtb, the key enzyme of the stringent response. We also report the phylogenetic evolution scenario that has shaped the current genetic organization, characterized by the coregulation of the hadABC operon with genes of the translational apparatus and with genes required for the modification of the mycolates. IMPORTANCE Mycobacterium tuberculosis infects one-third of the human population worldwide, and despite the available therapeutic arsenal, it continues to kill millions of people each year. There is therefore an urgent need to identify new targets and develop a better understanding of how the bacterium is adapting itself to host defenses during infection. A prerequisite of this understanding is knowledge of how this adaptive skill has been implanted by evolution. Nutrient scarcity is an environmental condition the bacterium has to cope with during infection. In many bacteria, adaptation to starvation relies partly on the stringent response. M. tuberculosis's unique outer membrane layer, the mycomembrane, is crucial for its viability and virulence. Despite its being the target of the major antituberculosis drugs, only scattered information exists on how the genes required for biosynthesis of the mycomembrane are expressed and regulated during starvation. This work has addressed this issue as a step toward the identification of new targets in the fight against M. tuberculosis.
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Irzik K, van Ooyen J, Gätgens J, Krumbach K, Bott M, Eggeling L. Acyl-CoA sensing by FasR to adjust fatty acid synthesis in Corynebacterium glutamicum. J Biotechnol 2015; 192 Pt A:96-101. [PMID: 25449109 DOI: 10.1016/j.jbiotec.2014.10.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/02/2014] [Accepted: 10/23/2014] [Indexed: 11/28/2022]
Abstract
Corynebacterium glutamicum, like Mycobacterium tuberculosis, is a member of the Corynebacteriales, which have linear fatty acids and as branched fatty acids the mycolic acids. We identified accD1 and fasA as key genes of fatty acid synthesis, encoding the β-subunit of the acetyl-CoA carboxylase and a type-I fatty acid synthase, respectively, and observed their repression during growth on minimal medium with acetate. We also identified the transcriptional regulator FasR and its binding sites in the 5′ upstream regions of accD1 and fasA. In the present work we establish by co-isolation and gel-mobility shifts oleoyl-CoA and palmitoyl-CoA as effectors of FasR, and show by DNA microarray analysis that in presence of exogeneous fatty acids accD1 and fasA are repressed. These results are evidence that acyl-CoA derivatives derived from extracellular fatty acids interact with FasR to repress the genes of fatty acid synthesis. This model also explains the observed repression of accD1 and fasA during growth on acetate, where apparently the known high intracellular acetyl-CoA concentration during growth on this substrate requires reduced accD1 and fasA expression for fine control of de novo fatty acid synthesis. Consequently, this mechanism ensures that membrane lipid homeostasis is maintained when specific nutrients are available resulting in increased acetyl-CoA concentration, as is the case with acetate, or when fatty acids are directly available from the extracellular environment. However, the genes specific to mycolic acid synthesis, which are in part shared with linear fatty acid synthesis, are not controlled by FasR, which is in agreement with the fact that they can not be supplied from the extracellular environment but that their synthesis fully depends on a constant supply of linear fatty acid chains.
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Crystal Structure of Fad35R from Mycobacterium tuberculosis H37Rv in the Apo-State. PLoS One 2015; 10:e0124333. [PMID: 25938298 PMCID: PMC4418694 DOI: 10.1371/journal.pone.0124333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 03/04/2015] [Indexed: 11/19/2022] Open
Abstract
Fad35R from Mycobacterium tuberculosis binds to the promoter site of Fad35 operon and its DNA binding activities are reduced in the presence of tetracycline and palmitoyl-CoA. We resolved the crystal structure of Fad35R using single-wavelength anomalous diffraction method (SAD). Fad35R comprises canonical DNA binding domain (DBD) and ligand binding domain (LBD), but displays several distinct structural features. Two recognition helices of two monomers in the homodimer are separated by ~ 48 Å and two core triangle-shaped ligand binding cavities are well exposed to solvent. Structural comparison with DesT and QacR structures suggests that ligand binding-induced movement of α7, which adopts a straight conformation in the Fad35R, may be crucial to switch the conformational states between repressive and derepressive forms. Two DBDs are packed asymmetrically, creating an alternative dimer interface which coincides with the possible tetramer interface that connects the two canonical dimers. Quaternary state of alternative dimer mimics a closed-state structure in which two recognition helices are distanced at ~ 35 Å and ligand binding pockets are inaccessible. Results of biophysical studies indicate that Fad35R has the propensity to oligomerize in solution in the presence of tetracycline. We present the first structure of a FadR homologue from mycobacterium and the structure reveals DNA and ligand binding features of Fad35R and also provides a view on alternative quaternary states that mimic open and closed forms of the regulator.
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Zimhony O, Schwarz A, Raitses-Gurevich M, Peleg Y, Dym O, Albeck S, Burstein Y, Shakked Z. AcpM, the meromycolate extension acyl carrier protein of Mycobacterium tuberculosis, is activated by the 4'-phosphopantetheinyl transferase PptT, a potential target of the multistep mycolic acid biosynthesis. Biochemistry 2015; 54:2360-71. [PMID: 25785780 DOI: 10.1021/bi501444e] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Modification of acyl carrier proteins (ACP) or domains by the covalent binding of a 4'-phosphopantetheine (4'-PP) moiety is a fundamental condition for activation of fatty acid synthases (FASes) and polyketide synthases (PKSes). Binding of 4'-PP is mediated by 4' phosphopantetheinyl transfersases (PPTases). Mycobacterium tuberculosis (Mtb) possesses two essential PPTases: acyl carrier protein synthase (Mtb AcpS), which activates the multidomain fatty acid synthase I (FAS I), and Mtb PptT, an Sfp-type broad spectrum PPTase that activates PKSes. To date, it has not been determined which of the two Mtb PPTases, AcpS or PptT, activates the meromycolate extension ACP, Mtb AcpM, en route to the production of mycolic acids, the main components of the mycobacterial cell wall. In this study, we tested the enzymatic activation of a highly purified Mtb apo-AcpM to Mtb holo-AcpM by either Mtb PptT or Mtb AcpS. By using SDS-PAGE band shift assay and mass spectrometry analysis, we found that Mtb PptT is the PPTase that activates Mtb AcpM. We measured the catalytic activity of Mtb PptT toward CoA, using an activation assay of a blue pigment synthase, BpsA (a nonribosomal peptide synthase, NRPS). BpsA activation by Mtb PptT was inhibited by Mtb apo-AcpM through competition for CoA, in accord with Mtb AcpM activation. A structural model of the putative interaction between Mtb PptT and Mtb AcpM suggests that both hydrophobic and electrostatic interactions stabilize this complex. To conclude, activation of Mtb AcpM by Mtb PptT reveals a potential target of the multistep mycolic acid biosynthesis.
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Affiliation(s)
- Oren Zimhony
- †Kaplan Medical Center, Affiliated to the School of Medicine, Hebrew University of Jerusalem and Hadassah Medical Center, POB1 Rehovot 76100, Israel
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Abstract
Mycobacterium tuberculosis, which is the aetiological agent of tuberculosis, owes much of its success as a pathogen to its unique cell wall and unusual mechanism of growth, which facilitate its adaptation to the human host and could have a role in clinical latency. Asymmetric growth and division increase population heterogeneity, which may promote antibiotic tolerance and the fitness of single cells. In this Review, we describe the unusual mechanisms of mycobacterial growth, cell wall biogenesis and division, and discuss how these processes might affect the survival of M. tuberculosis in vivo and contribute to the persistence of infection.
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Casabon I, Zhu SH, Otani H, Liu J, Mohn WW, Eltis LD. Regulation of the KstR2 regulon of Mycobacterium tuberculosis by a cholesterol catabolite. Mol Microbiol 2013; 89:1201-12. [PMID: 23879670 DOI: 10.1111/mmi.12340] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2013] [Indexed: 11/28/2022]
Abstract
Cholesterol catabolism is widespread in actinobacteria and is critical for Mycobacterium tuberculosis (Mtb) virulence. Catabolism of steroid nucleus rings C and D is poorly understood: it is initiated by the CoA thioesterification of 3aα-H-4α(3'-propanoate)-7aβ-methylhexahydro-1,5-indanedione (HIP) by FadD3, whose gene is part of the KstR2 regulon. In Mtb, genes of this regulon were upregulated up to 30- and 22-fold during growth on cholesterol and HIP, respectively, versus another minimal medium. In contrast, genes involved in degrading the cholesterol side-chain and nucleus rings A and B were only upregulated during growth on cholesterol. Similar results were obtained in Rhodococcus jostii RHA1. Moreover, the regulon was not upregulated in a ΔfadD3 mutant unable to produce HIP-CoA. In electrophoretic mobility shift assays, HIP-CoA relieved the binding of KstR2(Mtb) to each of three KstR2 boxes: CoASH, HIP and a related CoA thioester did not. Inspection of the structure of KstR2(RHA1) revealed no obvious HIP-CoA binding pocket. The results establish that Mtb can catabolize the entire cholesterol molecule and that HIP-CoA is an effector of KstR2. They further indicate that KstR2 specifically represses the expression of the HIP degradation genes in actinobacteria, which encode a lower pathway involved in the catabolism of multiple steroids.
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Affiliation(s)
- Israël Casabon
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
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