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Miotto P, Sorrentino R, De Giorgi S, Provvedi R, Cirillo DM, Manganelli R. Transcriptional regulation and drug resistance in Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:990312. [PMID: 36118045 PMCID: PMC9480834 DOI: 10.3389/fcimb.2022.990312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
Bacterial drug resistance is one of the major challenges to present and future human health, as the continuous selection of multidrug resistant bacteria poses at serious risk the possibility to treat infectious diseases in the near future. One of the infection at higher risk to become incurable is tuberculosis, due to the few drugs available in the market against Mycobacterium tuberculosis. Drug resistance in this species is usually due to point mutations in the drug target or in proteins required to activate prodrugs. However, another interesting and underexplored aspect of bacterial physiology with important impact on drug susceptibility is represented by the changes in transcriptional regulation following drug exposure. The main regulators involved in this phenomenon in M. tuberculosis are the sigma factors, and regulators belonging to the WhiB, GntR, XRE, Mar and TetR families. Better understanding the impact of these regulators in survival to drug treatment might contribute to identify new drug targets and/or to design new strategies of intervention.
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Affiliation(s)
- Paolo Miotto
- Emerging Bacterial Pathogens Unit, Div. of Immunology, Transplantation and Infectious Diseases IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Rita Sorrentino
- Emerging Bacterial Pathogens Unit, Div. of Immunology, Transplantation and Infectious Diseases IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Stefano De Giorgi
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | | | - Daniela Maria Cirillo
- Emerging Bacterial Pathogens Unit, Div. of Immunology, Transplantation and Infectious Diseases IRCCS San Raffaele Scientific Institute, Milano, Italy
| | - Riccardo Manganelli
- Department of Molecular Medicine, University of Padova, Padova, Italy
- *Correspondence: Riccardo Manganelli,
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Stokas H, Rhodes HL, Simmons MB, Zhang R, Wright CC, Purdy GE. M. tuberculosis AlkX Encoded by rv3249c Regulates a Conserved Alkane Hydroxylase System That Is Important for Replication in Macrophages and Biofilm Formation. Microbiol Spectr 2022;:e0196922. [PMID: 35938806 DOI: 10.1128/spectrum.01969-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis is a highly specialized human pathogen. The success of M. tuberculosis is due to its ability to replicate within host macrophages, resist host immune responses, and ultimately enter a persistent state during a latent tuberculosis infection. Understanding how M. tuberculosis adapts to and replicates in the intracellular environment of the host is crucial for the development of novel, targeted therapeutics. We report the characterization of an M. tuberculosis mutant lacking Rv3249c, a TetR transcriptional regulator. We show that Rv3249c directly represses the adjacent alkB-rubA-rubB operon encoding an alkane hydroxylase/rubredoxin system. For consistency with related systems, we have named the rv3249c gene alkX. The alkX mutant survived better than wild-type M. tuberculosis inside macrophages. This could be phenocopied by overexpression of the alkB-rubA-rubB locus. We hypothesized that the improved intracellular survival phenotype is a result of increased fitness of the mutant; however, we found that the alkX mutant had a defect when grown on some host-associated carbon sources in vitro. We also found that the alkX mutant had a defect in biofilm formation, also linked to the overexpression of the alkB-rubAB genes. Combined, these results define the primary role of AlkX as a transcriptional repressor of the alkB-rubAB operon and suggest the operon contributes to intracellular survival of the pathogen. IMPORTANCE Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is the leading cause of death worldwide due to a single infectious agent. It is important to understand how M. tuberculosis adapts to and replicates in the intracellular environment of the host. In this study, we characterized the TetR transcriptional regulator Rv3249c and show that it regulates a highly conserved alkane hydroxylase/rubredoxin system. Our data demonstrate that the AlkBRubAB system contributes to the success of the bacterium in host macrophages.
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Khan MT, Khan TA, Ahmad I, Muhammad S, Wei DQ. Diversity and novel mutations in membrane transporters of Mycobacterium tuberculosis. Brief Funct Genomics 2022; 22:168-179. [PMID: 35868449 DOI: 10.1093/bfgp/elac018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/29/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis (TB), encodes a family of membrane proteins belonging to Resistance-Nodulation-Cell Division (RND) permeases also called multidrug resistance pumps. Mycobacterial membrane protein Large (MmpL) transporters represent a subclass of RND transporters known to participate in exporting of lipid components across the cell envelope. These proteins perform an essential role in MTB survival; however, there are no data regarding mutations in MmpL, polyketide synthase (PKS) and acyl-CoA dehydrogenase FadE proteins from Khyber Pakhtunkhwa, Pakistan. This study aimed to screen mutations in transmembrane transporter proteins including MmpL, PKS and Fad through whole-genome sequencing (WGS) in local isolates of Khyber Pakhtunkhwa province, Pakistan. Fourteen samples were collected from TB patients and drug susceptibility testing was performed. However, only three samples were completely sequenced. Moreover, 209 whole-genome sequences of the same geography were also retrieved from NCBI GenBank to analyze the diversity of mutations in MmpL, PKS and Fad proteins. Among the 212 WGS (Accession ID: PRJNA629298, PRJNA629388, and ERR2510337-ERR2510345, ERR2510546-ERR2510645), numerous mutations in Fad (n = 756), PKS (n = 479), and MmpL (n = 306) have been detected. Some novel mutations were also detected in MmpL, PKS and acyl-CoA dehydrogenase Fad. Novel mutations including Asn576Ser in MmpL8, Val943Gly in MmpL9 and Asn145Asp have been detected in MmpL3. The presence of a large number of mutations in the MTB membrane may have functional consequences on proteins. However, further experimental studies are needed to elucidate the variants' effect on MmpL, PKS and FadE functions.
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Affiliation(s)
- Muhammad Tahir Khan
- Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, Pakistan
| | - Taj Ali Khan
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Phase V, Hayatabad, Peshawar, Khyber Pakhtunkhwa, 26000, Pakistan
| | - Irshad Ahmad
- Department of Molecular Biology and Genetics. Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan
| | - Shabbir Muhammad
- Department of Chemistry, College of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
| | - Dong-Qing Wei
- State Key Laboratory of Microbial Metabolism, Shanghai-Islamabad-Belgrade Joint Innovation Center on Antibacterial Resistances, Joint Laboratory of International Cooperation in Metabolic and Developmental Sciences, Ministry of Education and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, P.R. China.,Peng Cheng Laboratory, Vanke Cloud City Phase I Building 8, Xili Street, Nanshan District, Shenzhen, Guangdong, 518055, P.R. China
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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: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Batt SM, Minnikin DE, Besra GS. The thick waxy coat of mycobacteria, a protective layer against antibiotics and the host's immune system. Biochem J 2020; 477:1983-2006. [PMID: 32470138 DOI: 10.1042/BCJ20200194] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/22/2022]
Abstract
Tuberculosis, caused by the pathogenic bacterium Mycobacterium tuberculosis (Mtb), is the leading cause of death from an infectious disease, with a mortality rate of over a million people per year. This pathogen's remarkable resilience and infectivity is largely due to its unique waxy cell envelope, 40% of which comprises complex lipids. Therefore, an understanding of the structure and function of the cell wall lipids is of huge indirect clinical significance. This review provides a synopsis of the cell envelope and the major lipids contained within, including structure, biosynthesis and roles in pathogenesis.
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Aswal M, Garg A, Singhal N, Kumar M. Comparative in-silico proteomic analysis discerns potential granuloma proteins of Yersinia pseudotuberculosis. Sci Rep 2020; 10:3036. [PMID: 32080254 PMCID: PMC7033130 DOI: 10.1038/s41598-020-59924-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/03/2020] [Indexed: 11/29/2022] Open
Abstract
Yersinia pseudotuberculosis is one of the three pathogenic species of the genus Yersinia. Most studies regarding pathogenesis of Y. pseudotuberculosis are based on the proteins related to Type III secretion system, which is a well-known primary virulence factor in pathogenic Gram-negative bacteria, including Y. pseudotuberculosis. Information related to the factors involved in Y. pseudotuberculosis granuloma formation is scarce. In the present study we have used a computational approach to identify proteins that might be potentially involved in formation of Y. pseudotuberculosis granuloma. A comparative proteome analysis and conserved orthologous protein identification was performed between two different genera of bacteria - Mycobacterium and Yersinia, their only common pathogenic trait being ability to form necrotizing granuloma. Comprehensive analysis of orthologous proteins was performed in proteomes of seven bacterial species. This included M. tuberculosis, M. bovis and M. avium paratuberculosis - the known granuloma forming Mycobacterium species, Y. pestis and Y. frederiksenii - the non-granuloma forming Yersinia species and, Y. enterocolitica - that forms micro-granuloma and, Y. pseudotuberculosis - a prominent granuloma forming Yersinia species. In silico proteome analysis indicated that seven proteins (UniProt id A0A0U1QT64, A0A0U1QTE0, A0A0U1QWK3, A0A0U1R1R0, A0A0U1R1Z2, A0A0U1R2S7, A7FMD4) might play some role in Y. pseudotuberculosis granuloma. Validation of the probable involvement of the seven proposed Y. pseudotuberculosis granuloma proteins was done using transcriptome data analysis and, by mapping on a composite protein-protein interaction map of experimentally proved M. tuberculosis granuloma proteins (RD1 locus proteins, ESAT-6 secretion system proteins and intra-macrophage secreted proteins). Though, additional experiments involving knocking out of each of these seven proteins are required to confirm their role in Y. pseudotuberculosis granuloma our study can serve as a basis for further studies on Y. pseudotuberculosis granuloma.
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Affiliation(s)
- Manisha Aswal
- Department of Biophysics, University of Delhi South Campus, New Delhi, 110021, India
| | - Anjali Garg
- Department of Biophysics, University of Delhi South Campus, New Delhi, 110021, India
| | - Neelja Singhal
- Department of Biophysics, University of Delhi South Campus, New Delhi, 110021, India
| | - Manish Kumar
- Department of Biophysics, University of Delhi South Campus, New Delhi, 110021, India.
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Kang SM, Kim DH, Jin C, Ahn HC, Lee BJ. The crystal structure of AcrR from Mycobacterium tuberculosis reveals a one-component transcriptional regulation mechanism. FEBS Open Bio 2019; 9:1713-1725. [PMID: 31369208 PMCID: PMC6768106 DOI: 10.1002/2211-5463.12710] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/23/2019] [Accepted: 07/31/2019] [Indexed: 12/15/2022] Open
Abstract
Transcriptional regulator proteins are closely involved in essential survival strategies in bacteria. AcrR is a one-component allosteric repressor of the genes associated with lipid transport and antibiotic resistance. When fatty acid ligands bind to the C-terminal ligand-binding cavity of AcrR, a conformational change in the N-terminal operator-binding region of AcrR is triggered, which releases the repressed DNA and initiates transcription. This paper focuses on the structural transition mechanism of AcrR of Mycobacterium tuberculosis upon DNA and ligand binding. AcrR loses its structural integrity upon ligand-mediated structural alteration and bends toward the promoter DNA in a more compact form, initiating a rotational motion. Our functional characterization of AcrR and description of the ligand- and DNA-recognition mechanism may facilitate the discovery of new therapies for tuberculosis.
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Affiliation(s)
- Sung-Min Kang
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Do-Hee Kim
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Chenglong Jin
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
| | - Hee-Chul Ahn
- Department of Pharmacy, Dongguk University-Seoul, Ilsandong-gu, Goyang, Korea
| | - Bong-Jin Lee
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Korea
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Te Brake LHM, de Knegt GJ, de Steenwinkel JE, van Dam TJP, Burger DM, Russel FGM, van Crevel R, Koenderink JB, Aarnoutse RE. The Role of Efflux Pumps in Tuberculosis Treatment and Their Promise as a Target in Drug Development: Unraveling the Black Box. Annu Rev Pharmacol Toxicol 2017; 58:271-291. [PMID: 28715978 DOI: 10.1146/annurev-pharmtox-010617-052438] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Insight into drug transport mechanisms is highly relevant to the efficacious treatment of tuberculosis (TB). Major problems in TB treatment are related to the transport of antituberculosis (anti-TB) drugs across human and mycobacterial membranes, affecting the concentrations of these drugs systemically and locally. Firstly, transporters located in the intestines, liver, and kidneys all determine the pharmacokinetics and pharmacodynamics of anti-TB drugs, with a high risk of drug-drug interactions in the setting of concurrent use of antimycobacterial, antiretroviral, and antidiabetic agents. Secondly, human efflux transporters limit the penetration of anti-TB drugs into the brain and cerebrospinal fluid, which is especially important in the treatment of TB meningitis. Finally, efflux transporters located in the macrophage and Mycobacterium tuberculosis cell membranes play a pivotal role in the emergence of phenotypic tolerance and drug resistance, respectively. We review the role of efflux transporters in TB drug disposition and evaluate the promise of efflux pump inhibition from a novel holistic perspective.
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Affiliation(s)
- Lindsey H M Te Brake
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; .,Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Gerjo J de Knegt
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Jurriaan E de Steenwinkel
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands
| | - Teunis J P van Dam
- Centre for Molecular and Biomolecular Informatics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - David M Burger
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Reinout van Crevel
- Department of Internal Medicine, Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Jan B Koenderink
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Rob E Aarnoutse
- Department of Pharmacy, Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
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Aguilar-Ayala DA, Palomino JC, Vandamme P, Martin A, Gonzalez-Y-Merchand JA. "Genetic regulation of Mycobacterium tuberculosis in a lipid-rich environment". Infect Genet Evol 2016; 55:392-402. [PMID: 27771519 DOI: 10.1016/j.meegid.2016.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 10/15/2016] [Accepted: 10/18/2016] [Indexed: 01/19/2023]
Abstract
Tuberculosis (TB) remains as one of the leading causes of morbidity and mortality among infectious diseases worldwide. Although lipids (mainly fatty acids and cholesterol) have been reported to play an important role during active and latent infection of M. tuberculosis, there are other molecular aspects of bacterial response to those substrates that are not fully understood, involving gene regulation background. This review highlights recent insights on pathogen gene expression: regulation during its active growth, during survival in presence of lipids and under variable hostile host microenvironments. We also propose several application options of this knowledge that may contribute for improved TB control.
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Affiliation(s)
- Diana A Aguilar-Ayala
- Departamento de Microbiologia, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prolongacion de Carpio y Plan de Ayala S/N, Mexico City, Mexico; Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium
| | - Juan Carlos Palomino
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium
| | - Peter Vandamme
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium
| | - Anandi Martin
- Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium.
| | - Jorge A Gonzalez-Y-Merchand
- Departamento de Microbiologia, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prolongacion de Carpio y Plan de Ayala S/N, Mexico City, Mexico; Red Multidisciplinaria de Investigación en Tuberculosis, Mexico.
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11
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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