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Arejan NH, Czapski DR, Buonomo JA, Boutte CC. MmpL3, Wag31 and PlrA are involved in coordinating polar growth with peptidoglycan metabolism and nutrient availability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591792. [PMID: 38746181 PMCID: PMC11092516 DOI: 10.1101/2024.04.29.591792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Cell growth in mycobacteria involves cell wall expansion that is restricted to the cell poles. The DivIVA homolog Wag31 is required for this process, but the molecular mechanism and protein partners of Wag31 have not been described. In this study of Mycobacterium smegmatis, we identify a connection between wag31 and trehalose monomycolate (TMM) transporter mmpl3 in a suppressor screen, and show that Wag31 and polar regulator PlrA are required for MmpL3's polar localization. In addition, the localization of PlrA and MmpL3 are responsive to nutrient and energy deprivation and inhibition of peptidoglycan metabolism. We show that inhibition of MmpL3 causes delocalized cell wall metabolism, but does not delocalize MmpL3 itself. We found that cells with an MmpL3 C-terminal truncation, which is defective for localization, have only minor defects in polar growth, but are impaired in their ability to downregulate cell wall metabolism under stress. Our work suggests that, in addition to its established function in TMM transport, MmpL3 has a second function in regulating global cell wall metabolism in response to stress. Our data are consistent with a model in which the presence of TMMs in the periplasm stimulates polar elongation, and in which the connection between Wag31, PlrA and the C-terminus of MmpL3 is involved in detecting and responding to stress in order to coordinate synthesis of the different layers of the mycobacterial cell wall in changing conditions.
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Affiliation(s)
| | - Desiree R Czapski
- Department of Chemistry and Biochemistry, University of Texas, Arlington
| | - Joseph A Buonomo
- Department of Chemistry and Biochemistry, University of Texas, Arlington
| | - Cara C Boutte
- Department of Biology, University of Texas, Arlington
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2
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Sodani M, Misra CS, Nigam G, Fatima Z, Kulkarni S, Rath D. MSMEG_0311 is a conserved essential polar protein involved in mycobacterium cell wall metabolism. Int J Biol Macromol 2024; 260:129583. [PMID: 38242409 DOI: 10.1016/j.ijbiomac.2024.129583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/16/2024] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
Cell wall synthesis and cell division are two closely linked pathways in a bacterial cell which distinctly influence the growth and survival of a bacterium. This requires an appreciable coordination between the two processes, more so, in case of mycobacteria with an intricate multi-layered cell wall structure. In this study, we investigated a conserved gene cluster using CRISPR-Cas12 based gene silencing technology to show that knockdown of most of the genes in this cluster leads to growth defects. Investigating conserved genes is important as they likely perform vital cellular functions and the functional insights on such genes can be extended to other mycobacterial species. We characterised one of the genes in the locus, MSMEG_0311. The repression of this gene not only imparts severe growth defect but also changes colony morphology. We demonstrate that the protein preferentially localises to the polar region and investigate its influence on the polar growth of the bacillus. A combination of permeability and drug susceptibility assay strongly suggests a cell wall associated function of this gene which is also corroborated by transcriptomic analysis of the knockdown where a number of cell wall associated genes, particularly iniA and sigF regulon get altered. Considering the gene is highly conserved across mycobacterial species and appears to be essential for growth, it may serve as a potential drug target.
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Affiliation(s)
- Megha Sodani
- Radiation Medicine Centre, Medical Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra, India
| | - Chitra S Misra
- Applied Genomics Section, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Gaurav Nigam
- Amity Institute of Biotechnology, Amity University Haryana, Gurugram, India
| | - Zeeshan Fatima
- Amity Institute of Biotechnology, Amity University Haryana, Gurugram, India; Department of Laboratory Medicine, Faculty of Applied Medical Sciences, University of Bisha, Bisha, Saudi Arabia
| | - Savita Kulkarni
- Radiation Medicine Centre, Medical Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra, India.
| | - Devashish Rath
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra, India; Applied Genomics Section, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
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3
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Gwin CM, Gupta KR, Lu Y, Shao L, Rego EH. Spatial segregation and aging of metabolic processes underlie phenotypic heterogeneity in mycobacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.569614. [PMID: 38076906 PMCID: PMC10705497 DOI: 10.1101/2023.12.01.569614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Individual cells within clonal populations of mycobacteria vary in size, growth rate, and antibiotic susceptibility. Heterogeneity is, in part, determined by LamA, a protein found exclusively in mycobacteria. LamA localizes to sites of new cell wall synthesis where it recruits proteins important for polar growth and establishing asymmetry. Here, we report that in addition to this function, LamA interacts with complexes involved in oxidative phosphorylation (OXPHOS) at a subcellular location distinct from cell wall synthesis. Importantly, heterogeneity depends on a unique extension of the mycobacterial ATP synthase, and LamA mediates the coupling between ATP production and cell growth in single cells. Strikingly, as single cells age, concentrations of proteins important for oxidative phosphorylation become less abundant, and older cells rely less on oxidative phosphorylation for growth. Together, our data reveal that central metabolism is spatially organized within a single mycobacterium and varies within a genetically identical population of mycobacteria. Designing therapeutic regimens to account for this heterogeneity may help to treat mycobacterial infections faster and more completely.
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Affiliation(s)
- Celena M. Gwin
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06519
| | - Kuldeepkumar R. Gupta
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06519
| | - Yao Lu
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06519
| | - Lin Shao
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06519
| | - E. Hesper Rego
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06519
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North EJ, Schwartz CP, Zgurskaya HI, Jackson M. Recent advances in mycobacterial membrane protein large 3 inhibitor drug design for mycobacterial infections. Expert Opin Drug Discov 2023; 18:707-724. [PMID: 37226498 PMCID: PMC10330604 DOI: 10.1080/17460441.2023.2218082] [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: 03/31/2023] [Accepted: 05/22/2023] [Indexed: 05/26/2023]
Abstract
INTRODUCTION Tuberculosis and nontuberculous mycobacterial infections are notoriously difficult to treat, requiring long-courses of intensive multi-drug therapies associated with adverse side effects. To identify better therapeutics, whole cell screens have identified novel pharmacophores, a surprisingly high number of which target an essential lipid transporter known as MmpL3. AREAS COVERED This paper summarizes what is known about MmpL3, its mechanism of lipid transport and therapeutic potential, and provides an overview of the different classes of MmpL3 inhibitors currently under development. It further describes the assays available to study MmpL3 inhibition by these compounds. EXPERT OPINION MmpL3 has emerged as a target of high therapeutic value. Accordingly, several classes of MmpL3 inhibitors are currently under development with one drug candidate (SQ109) having undergone a Phase 2b clinical study. The hydrophobic character of most MmpL3 series identified to date seems to drive antimycobacterial potency resulting in poor bioavailability, which is a significant impediment to their development. There is also a need for more high-throughput and informative assays to elucidate the precise mechanism of action of MmpL3 inhibitors and drive the rational optimization of analogues.
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Affiliation(s)
- E. Jeffrey North
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Chris P. Schwartz
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Helen I. Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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Thouvenel L, Rech J, Guilhot C, Bouet JY, Chalut C. In vivo imaging of MmpL transporters reveals distinct subcellular locations for export of mycolic acids and non-essential trehalose polyphleates in the mycobacterial outer membrane. Sci Rep 2023; 13:7045. [PMID: 37120636 PMCID: PMC10148836 DOI: 10.1038/s41598-023-34315-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 04/27/2023] [Indexed: 05/01/2023] Open
Abstract
The mycobacterial cell envelope consists of a typical plasma membrane, surrounded by a complex cell wall and a lipid-rich outer membrane. The biogenesis of this multilayer structure is a tightly regulated process requiring the coordinated synthesis and assembly of all its constituents. Mycobacteria grow by polar extension and recent studies showed that cell envelope incorporation of mycolic acids, the major constituent of the cell wall and outer membrane, is coordinated with peptidoglycan biosynthesis at the cell poles. However, there is no information regarding the dynamics of incorporation of other families of outer membrane lipids during cell elongation and division. Here, we establish that the translocation of non-essential trehalose polyphleates (TPP) occurs at different subcellular locations than that of the essential mycolic acids. Using fluorescence microscopy approaches, we investigated the subcellular localization of MmpL3 and MmpL10, respectively involved in the export of mycolic acids and TPP, in growing cells and their colocalization with Wag31, a protein playing a critical role in regulating peptidoglycan biosynthesis in mycobacteria. We found that MmpL3, like Wag31, displays polar localization and preferential accumulation at the old pole whereas MmpL10 is more homogenously distributed in the plasma membrane and slightly accumulates at the new pole. These results led us to propose a model in which insertion of TPP and mycolic acids into the mycomembrane is spatially uncoupled.
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Affiliation(s)
- Laurie Thouvenel
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
- de Duve Institute, UCLouvain, Brussels, Belgium
| | - Jérôme Rech
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative de Toulouse, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Christophe Guilhot
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Jean-Yves Bouet
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative de Toulouse, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Christian Chalut
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France.
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Williams JT, Abramovitch RB. Molecular Mechanisms of MmpL3 Function and Inhibition. Microb Drug Resist 2023; 29:190-212. [PMID: 36809064 PMCID: PMC10171966 DOI: 10.1089/mdr.2021.0424] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Mycobacteria species include a large number of pathogenic organisms such as Mycobacterium tuberculosis, Mycobacterium leprae, and various non-tuberculous mycobacteria. Mycobacterial membrane protein large 3 (MmpL3) is an essential mycolic acid and lipid transporter required for growth and cell viability. In the last decade, numerous studies have characterized MmpL3 with respect to protein function, localization, regulation, and substrate/inhibitor interactions. This review summarizes new findings in the field and seeks to assess future areas of research in our rapidly expanding understanding of MmpL3 as a drug target. An atlas of known MmpL3 mutations that provide resistance to inhibitors is presented, which maps amino acid substitutions to specific structural domains of MmpL3. In addition, chemical features of distinct classes of Mmpl3 inhibitors are compared to provide insights into shared and unique features of varied MmpL3 inhibitors.
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Affiliation(s)
- John T Williams
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Robert B Abramovitch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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Stevens CM, Babii SO, Pandya AN, Li W, Li Y, Mehla J, Scott R, Hegde P, Prathipati PK, Acharya A, Liu J, Gumbart JC, North J, Jackson M, Zgurskaya HI. Proton transfer activity of the reconstituted Mycobacterium tuberculosis MmpL3 is modulated by substrate mimics and inhibitors. Proc Natl Acad Sci U S A 2022; 119:e2113963119. [PMID: 35858440 PMCID: PMC9335285 DOI: 10.1073/pnas.2113963119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 06/03/2022] [Indexed: 01/21/2023] Open
Abstract
Transporters belonging to the Resistance-Nodulation-cell Division (RND) superfamily of proteins such as Mycobacterium tuberculosis MmpL3 and its analogs are the focus of intense investigations due to their importance in the physiology of Corynebacterium-Mycobacterium-Nocardia species and antimycobacterial drug discovery. These transporters deliver trehalose monomycolates, the precursors of major lipids of the outer membrane, to the periplasm by a proton motive force-dependent mechanism. In this study, we successfully purified, from native membranes, the full-length and the C-terminal truncated M. tuberculosis MmpL3 and Corynebacterium glutamicum CmpL1 proteins and reconstituted them into proteoliposomes. We also generated a series of substrate mimics and inhibitors specific to these transporters, analyzed their activities in the reconstituted proteoliposomes, and carried out molecular dynamics simulations of the model MmpL3 transporter at different pH. We found that all reconstituted proteins facilitate proton translocation across a phospholipid bilayer, but MmpL3 and CmpL1 differ dramatically in their responses to pH and interactions with substrate mimics and indole-2-carboxamide inhibitors. Our results further suggest that some inhibitors abolish the transport activity of MmpL3 and CmpL1 by inhibition of proton translocation.
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Affiliation(s)
- Casey M. Stevens
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Svitlana O. Babii
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Amitkumar N. Pandya
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523
| | - Yupeng Li
- College of Chemistry, Jilin University, 130012 Changchun, China
- Tang Aoqing Honors Program in Science, Jilin University, 130012 Changchun, China
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jitender Mehla
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Robyn Scott
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Pooja Hegde
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Pavan K. Prathipati
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Atanu Acharya
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jinchan Liu
- College of Chemistry, Jilin University, 130012 Changchun, China
- Tang Aoqing Honors Program in Science, Jilin University, 130012 Changchun, China
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - James C. Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jeffrey North
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
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Kriel NL, Newton-Foot M, Bennion OT, Aldridge BB, Mehaffy C, Belisle JT, Walzl G, Warren RM, Sampson SL, Gey van Pittius NC. Localization of EccA 3 at the growing pole in Mycobacterium smegmatis. BMC Microbiol 2022; 22:140. [PMID: 35590245 PMCID: PMC9118679 DOI: 10.1186/s12866-022-02554-6] [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] [Received: 03/10/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022] Open
Abstract
Background Bacteria require specialized secretion systems for the export of molecules into the extracellular space to modify their environment and scavenge for nutrients. The ESX-3 secretion system is required by mycobacteria for iron homeostasis. The ESX-3 operon encodes for one cytoplasmic component (EccA3) and five membrane components (EccB3 – EccE3 and MycP3). In this study we sought to identify the sub-cellular location of EccA3 of the ESX-3 secretion system in mycobacteria. Results Fluorescently tagged EccA3 localized to a single pole in the majority of Mycobacterium smegmatis cells and time-lapse fluorescent microscopy identified this pole as the growing pole. Deletion of ESX-3 did not prevent polar localization of fluorescently tagged EccA3, suggesting that EccA3 unipolar localization is independent of other ESX-3 components. Affinity purification - mass spectrometry was used to identify EccA3 associated proteins which may contribute to the localization of EccA3 at the growing pole. EccA3 co-purified with fatty acid metabolism proteins (FAS, FadA3, KasA and KasB), mycolic acid synthesis proteins (UmaA, CmaA1), cell division proteins (FtsE and FtsZ), and cell shape and cell cycle proteins (MurS, CwsA and Wag31). Secretion system related proteins Ffh, SecA1, EccA1, and EspI were also identified. Conclusions Time-lapse microscopy demonstrated that EccA3 is located at the growing pole in M. smegmatis. The co-purification of EccA3 with proteins known to be required for polar growth, mycolic acid synthesis, the Sec secretion system (SecA1), and the signal recognition particle pathway (Ffh) also suggests that EccA3 is located at the site of active cell growth. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02554-6.
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Affiliation(s)
- Nastassja L Kriel
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
| | - Mae Newton-Foot
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Owen T Bennion
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Bree B Aldridge
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Carolina Mehaffy
- Mycobacteria Research Laboratories, Department of Microbiology Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - John T Belisle
- Mycobacteria Research Laboratories, Department of Microbiology Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Gerhard Walzl
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Robin M Warren
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Samantha L Sampson
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Nico C Gey van Pittius
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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9
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Li M, Huang Q, Zhang W, Cao Y, Wang Z, Zhao Z, Zhang X, Zhang J. A Novel Acyl-AcpM-Binding Protein Confers Intrinsic Sensitivity to Fatty Acid Synthase Type II Inhibitors in Mycobacterium smegmatis. Front Microbiol 2022; 13:846722. [PMID: 35444621 PMCID: PMC9014085 DOI: 10.3389/fmicb.2022.846722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
The fatty acid synthase type II (FAS-II) multienzyme system is the main target of drugs to inhibit mycolic acid synthesis in mycobacterium. Meromycolate extension acyl carrier protein (AcpM) serves as the carrier of fatty acyl chain shuttling among the individual FAS-II components during the progression of fatty acid elongation. In this paper, MSMEG_5634 in Mycobacterium smegmatis was determined to be a helix-grip structure protein with a deep hydrophobic pocket, preferring to form a complex with acyl-AcpM containing a fatty acyl chain at the C36-52 length, which is the medium product of FAS-II. MSMEG_5634 interacted with FAS-II components and presented relative accumulation at the cellular pole. By forming the MSMEG_5634/acyl-AcpM complex, which is free from FAS-II, MSMEG_5634 could transport acyl-AcpM away from FAS-II. Deletion of the MSMEG_5634 gene in M. smegmatis resulted in a mutant with decreased sensitivity to isoniazid and triclosan, two inhibitors of the FAS-II system. The isoniazid and triclosan sensitivity of this mutant could be restored by the ectopic expression of MSMEG_5634 or Rv0910, the MSMEG_5634 homologous protein in Mycobacterium tuberculosis H37Rv. These results suggest that MSMEG_5634 and its homologous proteins, forming a novel acyl-AcpM-binding protein family in mycobacterium, confer intrinsic sensitivity to FAS-II inhibitors.
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Affiliation(s)
- Mengmiao Li
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Qian Huang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Weidi Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Yinghua Cao
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Zhanxin Wang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Zhenwen Zhao
- Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Xiaotian Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Junjie Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, China
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10
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Spatiotemporal localization of proteins in mycobacteria. Cell Rep 2021; 37:110154. [PMID: 34965429 PMCID: PMC8861988 DOI: 10.1016/j.celrep.2021.110154] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/16/2021] [Accepted: 12/01/2021] [Indexed: 01/10/2023] Open
Abstract
Although prokaryotic organisms lack traditional organelles, they must still organize cellular structures in space and time, challenges that different species solve differently. To systematically define the subcellular architecture of mycobacteria, we perform high-throughput imaging of a library of fluorescently tagged proteins expressed in Mycobacterium smegmatis and develop a customized computational pipeline, MOMIA and GEMATRIA, to analyze these data. Our results establish a spatial organization network of over 700 conserved mycobacterial proteins and reveal a coherent localization pattern for many proteins of known function, including those in translation, energy metabolism, cell growth and division, as well as proteins of unknown function. Furthermore, our pipeline exploits morphologic proxies to enable a pseudo-temporal approximation of protein localization and identifies previously uncharacterized cell-cycle-dependent dynamics of essential mycobacterial proteins. Collectively, these data provide a systems perspective on the subcellular organization of mycobacteria and provide tools for the analysis of bacteria with non-standard growth characteristics. Zhu et al. develop a two-stage image analysis pipeline, MOMIA and GEMATRIA, that efficiently models the spatial and temporal dynamics of over 700 conserved proteins in M. smegmatis. Through the analysis they report spatial constraints of mycobacterial ribosomes and membrane complexes and reconstruct temporal dynamics from still image data.
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11
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de Melo EH, Gomes HM, Suffys PN, Lopes MQP, de Figueiredo Teixeira RL, Dos Santos ÍR, Franco MMJ, Langoni H, Paes AC, Afonso JAB, de Mendonça CL. Genotypic Characterization of Mycobacterium bovis Isolates From Dairy Cattle Diagnosed With Clinical Tuberculosis. Front Vet Sci 2021; 8:747226. [PMID: 34708105 PMCID: PMC8542897 DOI: 10.3389/fvets.2021.747226] [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] [Received: 07/25/2021] [Accepted: 08/31/2021] [Indexed: 11/30/2022] Open
Abstract
Molecular diagnosis of bovine tuberculosis plays an essential role in the epidemiological knowledge of the disease. Bovine tuberculosis caused by Mycobacterium bovis represents a risk to human health. This study aimed to perform the genotypic characterization of M. bovis isolated from bovines diagnosed as tuberculosis from dairy herds in the state of Pernambuco, Brazil. Granulomas from 30 bovines were sent for microbiological culture, and colonies compatible with Mycobacterium spp. were obtained in at least one culture from 17/30 granulomas. All isolates were confirmed to be M. bovis by spoligotyping and 24loci MIRU-VNTR typing. While spoligotyping characterized the isolates as SB0121, SB0295, SB0852, SB0120, and an unclassified genotype, 24loci MIRU-VNTR rendered two clusters of two isolates each and 13 unique profiles. Loci ETR-A showed higher discriminatory power, and loci (ETR-B, ETR-C, MIRU16, MIRU27, and QUB26) showed moderate allelic diversity. This is the first study on the genetic variability of the infectious agent cause of bovine TB in Pernambuco and demonstrates variability of strains in the state. Thus, it corroborates the importance of this microorganism as agent of bovine tuberculosis and its zoonotic potential, this epidemiological tool being a determinant in the rigor of the sanitary practices of disease control in dairy herds.
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Affiliation(s)
| | - Harrison Magdinier Gomes
- Laboratório de Biologia Molecular Aplicada à Micobactérias, Fundação Oswaldo Cruz, Laboratório de Biologia Molecular Aplicada à Micobactérias, Rio de Janeiro, Brazil
| | - Philip Noel Suffys
- Laboratório de Biologia Molecular Aplicada à Micobactérias, Fundação Oswaldo Cruz, Laboratório de Biologia Molecular Aplicada à Micobactérias, Rio de Janeiro, Brazil
| | - Márcia Quinhones Pires Lopes
- Laboratório de Biologia Molecular Aplicada à Micobactérias, Fundação Oswaldo Cruz, Laboratório de Biologia Molecular Aplicada à Micobactérias, Rio de Janeiro, Brazil
| | - Raquel Lima de Figueiredo Teixeira
- Laboratório de Biologia Molecular Aplicada à Micobactérias, Fundação Oswaldo Cruz, Laboratório de Biologia Molecular Aplicada à Micobactérias, Rio de Janeiro, Brazil
| | - Ícaro Rodrigues Dos Santos
- Laboratório de Biologia Molecular Aplicada à Micobactérias, Fundação Oswaldo Cruz, Laboratório de Biologia Molecular Aplicada à Micobactérias, Rio de Janeiro, Brazil
| | - Marília Masello Junqueira Franco
- Departamento de Higiene Veterinária e Saúde Pública, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, Brazil
| | - Helio Langoni
- Departamento de Higiene Veterinária e Saúde Pública, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, Brazil
| | - Antonio Carlos Paes
- Departamento de Higiene Veterinária e Saúde Pública, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, Brazil
| | | | - Carla Lopes de Mendonça
- Clínica de Bovinos de Garanhuns, Universidade Federal Rural de Pernambuco, Garanhuns, Brazil
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12
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Santucci P, Greenwood DJ, Fearns A, Chen K, Jiang H, Gutierrez MG. Intracellular localisation of Mycobacterium tuberculosis affects efficacy of the antibiotic pyrazinamide. Nat Commun 2021; 12:3816. [PMID: 34155215 PMCID: PMC8217510 DOI: 10.1038/s41467-021-24127-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 05/28/2021] [Indexed: 11/09/2022] Open
Abstract
To be effective, chemotherapy against tuberculosis (TB) must kill the intracellular population of the pathogen, Mycobacterium tuberculosis. However, how host cell microenvironments affect antibiotic accumulation and efficacy remains unclear. Here, we use correlative light, electron, and ion microscopy to investigate how various microenvironments within human macrophages affect the activity of pyrazinamide (PZA), a key antibiotic against TB. We show that PZA accumulates heterogeneously among individual bacteria in multiple host cell environments. Crucially, PZA accumulation and efficacy is maximal within acidified phagosomes. Bedaquiline, another antibiotic commonly used in combined TB therapy, enhances PZA accumulation via a host cell-mediated mechanism. Thus, intracellular localisation and specific microenvironments affect PZA accumulation and efficacy. Our results may explain the potent in vivo efficacy of PZA, compared to its modest in vitro activity, and its critical contribution to TB combination chemotherapy.
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Affiliation(s)
- Pierre Santucci
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK
| | - Daniel J Greenwood
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK.,Institute of Molecular Systems Biology, ETH, Zurich, Switzerland
| | - Antony Fearns
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK
| | - Kai Chen
- School of Molecular Sciences, University of Western Australia, Perth, AU, Australia
| | - Haibo Jiang
- School of Molecular Sciences, University of Western Australia, Perth, AU, Australia. .,Department of Chemistry, The University of Hong Kong, Hong Kong, China.
| | - Maximiliano G Gutierrez
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, London, UK.
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13
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Direct Interaction of Polar Scaffolding Protein Wag31 with Nucleoid-Associated Protein Rv3852 Regulates Its Polar Localization. Cells 2021; 10:cells10061558. [PMID: 34203111 PMCID: PMC8233713 DOI: 10.3390/cells10061558] [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] [Received: 05/23/2021] [Revised: 06/12/2021] [Accepted: 06/16/2021] [Indexed: 11/25/2022] Open
Abstract
Rv3852 is a unique nucleoid-associated protein (NAP) found exclusively in Mycobacterium tuberculosis (Mtb) and closely related species. Although annotated as H-NS, we showed previously that it is very different from H-NS in its properties and is distinct from other NAPs, anchoring to cell membrane by virtue of possessing a C-terminal transmembrane helix. Here, we investigated the role of Rv3852 in Mtb in organizing architecture or synthesis machinery of cell wall by protein–protein interaction approach. We demonstrated a direct physical interaction of Rv3852 with Wag31, an important cell shape and cell wall integrity determinant essential in Mtb. Wag31 localizes to the cell poles and possibly acts as a scaffold for cell wall synthesis proteins, resulting in polar cell growth in Mtb. Ectopic expression of Rv3852 in M. smegmatis resulted in its interaction with Wag31 orthologue DivIVAMsm. Binding of the NAP to Wag31 appears to be necessary for fine-tuning Wag31 localization to the cell poles, enabling complex cell wall synthesis in Mtb. In Rv3852 knockout background, Wag31 is mislocalized resulting in disturbed nascent peptidoglycan synthesis, suggesting that the NAP acts as a driver for localization of Wag31 to the cell poles. While this novel association between these two proteins presents one of the mechanisms to structure the elaborate multi-layered cell envelope of Mtb, it also exemplifies a new function for a NAP in mycobacteria.
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14
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Farjallah A, Chiarelli LR, Forbak M, Degiacomi G, Danel M, Goncalves F, Carayon C, Seguin C, Fumagalli M, Záhorszká M, Vega E, Abid S, Grzegorzewicz A, Jackson M, Peixoto A, Korduláková J, Pasca MR, Lherbet C, Chassaing S. A Coumarin-Based Analogue of Thiacetazone as Dual Covalent Inhibitor and Potential Fluorescent Label of HadA in Mycobacterium tuberculosis. ACS Infect Dis 2021; 7:552-565. [PMID: 33617235 DOI: 10.1021/acsinfecdis.0c00325] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A novel coumarin-based molecule, designed as a fluorescent surrogate of a thiacetazone-derived antitubercular agent, was quickly and easily synthesized from readily available starting materials. This small molecule, coined Coum-TAC, exhibited a combination of appropriate physicochemical and biological properties, including resistance toward hydrolysis and excellent antitubercular efficiency similar to that of well-known thiacetazone derivatives, as well as efficient covalent labeling of HadA, a relevant therapeutic target to combat Mycobacterium tuberculosis. More remarkably, Coum-TAC was successfully implemented as an imaging probe that is capable of labeling Mycobacterium tuberculosis in a selective manner, with an enrichment at the level of the poles, thus giving for the first time relevant insights about the polar localization of HadA in the mycobacteria.
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Affiliation(s)
- Asma Farjallah
- ITAV, Université de Toulouse, CNRS USR3505, UPS, 1 place Pierre Potier, 31106 Toulouse Cedex 1, France
- Laboratoire de Chimie Appliquée: Hétérocycles, Corps Gras et Polymères, Faculté des sciences de Sfax, Université de Sfax, Sfax, Tunisie
| | - Laurent R. Chiarelli
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, via Ferrata 9, 27100 Pavia, Italy
| | - Martin Forbak
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Giulia Degiacomi
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, via Ferrata 9, 27100 Pavia, Italy
| | - Mathieu Danel
- ITAV, Université de Toulouse, CNRS USR3505, UPS, 1 place Pierre Potier, 31106 Toulouse Cedex 1, France
| | - Fernanda Goncalves
- ITAV, Université de Toulouse, CNRS USR3505, UPS, 1 place Pierre Potier, 31106 Toulouse Cedex 1, France
- Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique (SPCMIB), Université Paul Sabatier-Toulouse III/CNRS (UMR5068), 118 route de Narbonne, F-31062 Toulouse, France
| | - Chantal Carayon
- Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique (SPCMIB), Université Paul Sabatier-Toulouse III/CNRS (UMR5068), 118 route de Narbonne, F-31062 Toulouse, France
| | - Cendrine Seguin
- Laboratoire de Conception et Application de Molécules Bioactives (LCAMB), CNRS-UMR7199, Université de Strasbourg, Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Marco Fumagalli
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, via Ferrata 9, 27100 Pavia, Italy
| | - Monika Záhorszká
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Elodie Vega
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France
| | - Souhir Abid
- Chemistry Department, College of Science and Arts, Jouf University, Al Qurayyat, Saudi Arabia
- Laboratoire de Chimie Appliquée: Hétérocycles, Corps Gras et Polymères, Faculté des sciences de Sfax, Université de Sfax, Sfax, Tunisie
| | - Anna Grzegorzewicz
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States
| | - Antonio Peixoto
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France
| | - Jana Korduláková
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynská Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia
| | - Maria Rosalia Pasca
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, via Ferrata 9, 27100 Pavia, Italy
| | - Christian Lherbet
- ITAV, Université de Toulouse, CNRS USR3505, UPS, 1 place Pierre Potier, 31106 Toulouse Cedex 1, France
- Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique (SPCMIB), Université Paul Sabatier-Toulouse III/CNRS (UMR5068), 118 route de Narbonne, F-31062 Toulouse, France
| | - Stefan Chassaing
- ITAV, Université de Toulouse, CNRS USR3505, UPS, 1 place Pierre Potier, 31106 Toulouse Cedex 1, France
- Laboratoire de Synthèse, Réactivité Organiques & Catalyse (LASYROC), Institut de Chimie, CNRS-UMR7177, Université de Strasbourg, 4 rue Blaise Pascal, 67070 Strasbourg, France
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15
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Maitra A, Munshi T, Healy J, Martin LT, Vollmer W, Keep NH, Bhakta S. Cell wall peptidoglycan in Mycobacterium tuberculosis: An Achilles' heel for the TB-causing pathogen. FEMS Microbiol Rev 2020; 43:548-575. [PMID: 31183501 PMCID: PMC6736417 DOI: 10.1093/femsre/fuz016] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis, remains one of the leading causes of mortality across the world. There is an urgent requirement to build a robust arsenal of effective antimicrobials, targeting novel molecular mechanisms to overcome the challenges posed by the increase of antibiotic resistance in TB. Mycobacterium tuberculosis has a unique cell envelope structure and composition, containing a peptidoglycan layer that is essential for maintaining cellular integrity and for virulence. The enzymes involved in the biosynthesis, degradation, remodelling and recycling of peptidoglycan have resurfaced as attractive targets for anti-infective drug discovery. Here, we review the importance of peptidoglycan, including the structure, function and regulation of key enzymes involved in its metabolism. We also discuss known inhibitors of ATP-dependent Mur ligases, and discuss the potential for the development of pan-enzyme inhibitors targeting multiple Mur ligases.
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Affiliation(s)
- Arundhati Maitra
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Tulika Munshi
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Jess Healy
- Department of Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Liam T Martin
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Nicholas H Keep
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
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16
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Li M, Phua ZY, Xi Y, Xu Z, Nyantakyi SA, Li W, Jackson M, Wong MW, Lam Y, Chng SS, Go ML, Dick T. Potency Increase of Spiroketal Analogs of Membrane Inserting Indolyl Mannich Base Antimycobacterials Is Due to Acquisition of MmpL3 Inhibition. ACS Infect Dis 2020; 6:1882-1893. [PMID: 32413266 PMCID: PMC7875313 DOI: 10.1021/acsinfecdis.0c00121] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chemistry campaigns identified amphiphilic indolyl Mannich bases as novel membrane-permeabilizing antimycobacterials. Spiroketal analogs of this series showed increased potency, and the lead compound 1 displayed efficacy in a mouse model of tuberculosis. Yet the mechanism by which the spiroketal moiety accomplished the potency "jump" remained unknown. Consistent with its membrane-permeabilizing mechanism, no resistant mutants could be isolated against indolyl Mannich base 2 lacking the spiroketal moiety. In contrast, mutations resistant against spiroketal analog 1 were obtained in mycobacterial membrane protein large 3 (MmpL3), a proton motive force (PMF)-dependent mycolate transporter. Thus, we hypothesized that the potency jump observed for 1 may be due to MmpL3 inhibition acquired by the addition of the spiroketal moiety. Here we showed that 1 inhibited MmpL3 flippase activity without loss of the PMF, colocalized with MmpL3tb-GFP in intact organisms, and yielded a consistent docking pose within the "common inhibitor binding pocket" of MmpL3. The presence of the spiroketal motif in 1 ostensibly augmented its interaction with MmpL3, an outcome not observed in the nonspiroketal analog 2, which displayed no cross-resistance to mmpL3 mutants, dissipated the PMF, and docked poorly in the MmpL3 binding pocket. Surprisingly, 2 inhibited MmpL3 flippase activity, which may be an epiphenomenon arising from its wider membrane disruptive effects. Hence, we conclude that the potency increase associated with the spiroketal analog 1 is linked to the acquisition of a second mechanism, MmpL3 inhibition. In contrast, the nonspiroketal analog 2 acts pleiotropically, affecting several cell membrane-embedded targets, including MmpL3, through its membrane permeabilizing and depolarizing effects.
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Affiliation(s)
- Ming Li
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Zheng Yen Phua
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
| | - Yu Xi
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
| | - Zhujun Xu
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
| | - Samuel A. Nyantakyi
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Ming Wah Wong
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
| | - Yulin Lam
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
| | - Shu Sin Chng
- Department of Chemistry, Faculty of Science, National University of Singapore, Singapore
- Singapore Centre for Environmental Life Science Engineering (SCELSE), National University of Singapore, Singapore
| | - Mei Lin Go
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore
| | - Thomas Dick
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, NJ, USA
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17
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Parbhoo T, Sampson SL, Mouton JM. Recent Developments in the Application of Flow Cytometry to Advance our Understanding of Mycobacterium tuberculosis Physiology and Pathogenesis. Cytometry A 2020; 97:683-693. [PMID: 32437069 PMCID: PMC7496436 DOI: 10.1002/cyto.a.24030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/18/2020] [Accepted: 04/21/2020] [Indexed: 12/16/2022]
Abstract
The ability of the bacterial pathogen Mycobacterium tuberculosis to adapt and survive within human cells to disseminate to other individuals and cause active disease is poorly understood. Research supports that as M. tuberculosis adapts to stressors encountered in the host, it exhibits variable physiological and metabolic states that are time and niche-dependent. Challenges associated with effective treatment and eradication of tuberculosis (TB) are in part attributed to our lack of understanding of these different mycobacterial phenotypes. This is mainly due to a lack of suitable tools to effectively identify/detect heterogeneous bacterial populations, which may include small, difficult-to-culture subpopulations. Importantly, flow cytometry allows rapid and affordable multiparametric measurements of physical and chemical characteristics of single cells, without the need to preculture cells. Here, we summarize current knowledge of flow cytometry applications that have advanced our understanding of the physiology of M. tuberculosis during TB disease. Specifically, we review how host-associated stressors influence bacterial characteristics such as metabolic activity, membrane potential, redox status and the mycobacterial cell wall. Further, we highlight that flow cytometry offers unprecedented opportunities for insight into bacterial population heterogeneity, which is increasingly appreciated as an important determinant of disease outcome. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.
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Affiliation(s)
- Trisha Parbhoo
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Samantha L. Sampson
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Jacoba M. Mouton
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
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18
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Promiscuous Targets for Antitubercular Drug Discovery: The Paradigm of DprE1 and MmpL3. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10020623] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The development and spread of Mycobacterium tuberculosis multi-drug resistant strains still represent a great global health threat, leading to an urgent need for novel anti-tuberculosis drugs. Indeed, in the last years, several efforts have been made in this direction, through a number of high-throughput screenings campaigns, which allowed for the identification of numerous hit compounds and novel targets. Interestingly, several independent screening assays identified the same proteins as the target of different compounds, and for this reason, they were named “promiscuous” targets. These proteins include DprE1, MmpL3, QcrB and Psk13, and are involved in the key pathway for M. tuberculosis survival, thus they should represent an Achilles’ heel which could be exploited for the development of novel effective drugs. Indeed, among the last molecules which entered clinical trials, four inhibit a promiscuous target. Within this review, the two most promising promiscuous targets, the oxidoreductase DprE1 involved in arabinogalactan synthesis and the mycolic acid transporter MmpL3 are discussed, along with the latest advancements in the development of novel inhibitors with anti-tubercular activity.
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19
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Zhang B, Li J, Yang X, Wu L, Zhang J, Yang Y, Zhao Y, Zhang L, Yang X, Yang X, Cheng X, Liu Z, Jiang B, Jiang H, Guddat LW, Yang H, Rao Z. Crystal Structures of Membrane Transporter MmpL3, an Anti-TB Drug Target. Cell 2019; 176:636-648.e13. [PMID: 30682372 DOI: 10.1016/j.cell.2019.01.003] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/22/2018] [Accepted: 12/31/2018] [Indexed: 01/01/2023]
Abstract
Despite intensive efforts to discover highly effective treatments to eradicate tuberculosis (TB), it remains as a major threat to global human health. For this reason, new TB drugs directed toward new targets are highly coveted. MmpLs (Mycobacterial membrane proteins Large), which play crucial roles in transporting lipids, polymers and immunomodulators and which also extrude therapeutic drugs, are among the most important therapeutic drug targets to emerge in recent times. Here, crystal structures of mycobacterial MmpL3 alone and in complex with four TB drug candidates, including SQ109 (in Phase 2b-3 clinical trials), are reported. MmpL3 consists of a periplasmic pore domain and a twelve-helix transmembrane domain. Two Asp-Tyr pairs centrally located in this domain appear to be key facilitators of proton-translocation. SQ109, AU1235, ICA38, and rimonabant bind inside the transmembrane region and disrupt these Asp-Tyr pairs. This structural data will greatly advance the development of MmpL3 inhibitors as new TB drugs.
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Affiliation(s)
- Bing Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun Li
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Xiaolin Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Lijie Wu
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Jia Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yang Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yao Zhao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Lu Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300353, China
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiaobao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xi Cheng
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Zhijie Liu
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Biao Jiang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Hualiang Jiang
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Luke W Guddat
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Haitao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Zihe Rao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300353, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; Laboratory of Structural Biology, Tsinghua University, Beijing, 100084, China.
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20
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Choukate K, Gupta A, Basu B, Virk K, Ganguli M, Chaudhuri B. Higher order assembling of the mycobacterial polar growth factor DivIVA/Wag31. J Struct Biol 2019; 209:107429. [PMID: 31778770 DOI: 10.1016/j.jsb.2019.107429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/04/2019] [Accepted: 11/21/2019] [Indexed: 12/26/2022]
Abstract
DivIVA or Wag31, which is an essential pole organizing protein in mycobacteria, can self-assemble at the negatively curved side of the membrane at the growing pole to form a higher order structural scaffold for maintaining cellular morphology and localizing various target proteins for cell-wall biogenesis. The structural organization of polar scaffold formed by polymerization of coiled-coil rich Wag31, which is implicated in the anti-tubercular activities of amino-pyrimidine sulfonamides, remains to be determined. A single-site phosphorylation in Wag31 regulates peptidoglycan biosynthesis in mycobacteria. We report biophysical characterizations of filaments formed by mycobacterial Wag31 using circular dichroism, atomic force microscopy and small angle solution X-ray scattering. Atomic force microscopic images of the wild-type, a phospho-mimetic (T73E) and a phospho-ablative (T73A) form of Wag31 show mostly linear filament formation with occasional curving, kinking and apparent branching. Solution X-ray scattering data indicates that the phospho-mimetic forms of the Wag31 polymers are on average more compact than their phospho-ablative counterparts, which is likely due to the extent of bending/branching. Observed structural features in this first view of Wag31 filaments suggest a basis for higher order Wag31 scaffold formation at the pole.
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Affiliation(s)
- Komal Choukate
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Aanchal Gupta
- CSIR Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Brohmomoy Basu
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Karman Virk
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Munia Ganguli
- CSIR Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Barnali Chaudhuri
- CSIR Institute of Microbial Technology, Chandigarh, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.
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21
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Abstract
To survive under unpredictable conditions, all organisms must adapt to stressors by regulating adaptive cellular responses. Arrestin proteins are conserved regulators of adaptive cellular responses in eukaryotes. Studies that have been limited to mammals and model fungi have demonstrated that the disruption of arrestin-regulated pathways is detrimental for viability. The human fungal pathogen Cryptococcus neoformans causes more than 180,000 infection-related deaths annually, especially among immunocompromised patients. In addition to being genetically tractable, C. neoformans has a small arrestin family of four members, lending itself to a comprehensive characterization of its arrestin family. This study serves as a functional analysis of arrestins in a pathogen, particularly in the context of fungal fitness and virulence. We investigate the functions of one arrestin protein, Ali1, and define its novel contributions to cytokinesis. We additionally explore the virulence contributions of the C. neoformans arrestin family and find that they contribute to disease establishment and progression. Arrestins, a structurally specialized and functionally diverse group of proteins, are central regulators of adaptive cellular responses in eukaryotes. Previous studies on fungal arrestins have demonstrated their capacity to modulate diverse cellular processes through their adaptor functions, facilitating the localization and function of other proteins. However, the mechanisms by which arrestin-regulated processes are involved in fungal virulence remain unexplored. We have identified a small family of four arrestins, Ali1, Ali2, Ali3, and Ali4, in the human fungal pathogen Cryptococcus neoformans. Using complementary microscopy, proteomic, and reverse genetics techniques, we have defined a role for Ali1 as a novel contributor to cytokinesis, a fundamental cell cycle-associated process. We observed that Ali1 strongly interacts with proteins involved in lipid synthesis, and that ali1Δ mutant phenotypes are rescued by supplementation with lipid precursors that are used to build cellular membranes. From these data, we hypothesize that Ali1 contributes to cytokinesis by serving as an adaptor protein, facilitating the localization of enzymes that modify the plasma membrane during cell division, specifically the fatty acid synthases Fas1 and Fas2. Finally, we assessed the contributions of the C. neoformans arrestin family to virulence to better understand the mechanisms by which arrestin-regulated adaptive cellular responses influence fungal infection. We observed that the C. neoformans arrestin family contributes to virulence, and that the individual arrestin proteins likely fulfill distinct functions that are important for disease progression.
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22
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Dulberger CL, Rubin EJ, Boutte CC. The mycobacterial cell envelope - a moving target. Nat Rev Microbiol 2019; 18:47-59. [PMID: 31728063 DOI: 10.1038/s41579-019-0273-7] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 01/12/2023]
Abstract
Mycobacterium tuberculosis, the leading cause of death due to infection, has a dynamic and immunomodulatory cell envelope. The cell envelope structurally and functionally varies across the length of the cell and during the infection process. This variability allows the bacterium to manipulate the human immune system, tolerate antibiotic treatment and adapt to the variable host environment. Much of what we know about the mycobacterial cell envelope has been gleaned from model actinobacterial species, or model conditions such as growth in vitro, in macrophages and in the mouse. In this Review, we combine data from different experimental systems to build a model of the dynamics of the mycobacterial cell envelope across space and time. We describe the regulatory pathways that control metabolism of the cell wall and surface lipids in M. tuberculosis during growth and stasis, and speculate about how this regulation might affect antibiotic susceptibility and interactions with the immune system.
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Affiliation(s)
- Charles L Dulberger
- Department of Molecular and Cellular Biology, Harvard University, Boston, MA, USA.,Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Eric J Rubin
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Cara C Boutte
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.
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23
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Abstract
Reproduction in the bacterial kingdom predominantly occurs through binary fission-a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped Escherichia coli and Bacillus subtilis, which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.
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24
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Belardinelli JM, Stevens CM, Li W, Tan YZ, Jones V, Mancia F, Zgurskaya HI, Jackson M. The MmpL3 interactome reveals a complex crosstalk between cell envelope biosynthesis and cell elongation and division in mycobacteria. Sci Rep 2019; 9:10728. [PMID: 31341202 PMCID: PMC6656915 DOI: 10.1038/s41598-019-47159-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/08/2019] [Indexed: 01/19/2023] Open
Abstract
Integral membrane transporters of the Mycobacterial Membrane Protein Large (MmpL) family and their interactome play important roles in the synthesis and export of mycobacterial outer membrane lipids. Despite the current interest in the mycolic acid transporter, MmpL3, from the perspective of drug discovery, the nature and biological significance of its interactome remain largely unknown. We here report on a genome-wide screening by two-hybrid system for MmpL3 binding partners. While a surprisingly low number of proteins involved in mycolic acid biosynthesis was found to interact with MmpL3, numerous enzymes and transporters participating in the biogenesis of peptidoglycan, arabinogalactan and lipoglycans, and the cell division regulatory protein, CrgA, were identified among the hits. Surface plasmon resonance and co-immunoprecipitation independently confirmed physical interactions for three proteins in vitro and/or in vivo. Results are in line with the focal localization of MmpL3 at the poles and septum of actively-growing bacilli where the synthesis of all major constituents of the cell wall core are known to occur, and are further suggestive of a role for MmpL3 in the coordination of new cell wall deposition during cell septation and elongation. This novel aspect of the physiology of MmpL3 may contribute to the extreme vulnerability and high therapeutic potential of this transporter.
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Affiliation(s)
- Juan Manuel Belardinelli
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA
| | - Casey M Stevens
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA
| | - Yong Zi Tan
- Department of Physiology and Cellular Biophysics, Columbia University, 1150 St. Nicholas Avenue, New York, NY, 10032, USA
| | - Victoria Jones
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, 1150 St. Nicholas Avenue, New York, NY, 10032, USA
| | - Helen I Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA.
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25
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Abstract
Mycolic acids are the signature lipid of mycobacteria and constitute an important physical component of the cell wall, a target of mycobacterium-specific antibiotics and a mediator of Mycobacterium tuberculosis pathogenesis. Mycolic acids are synthesized in the cytoplasm and are thought to be transported to the cell wall as a trehalose ester by the MmpL3 transporter, an antibiotic target for M. tuberculosis However, the mechanism by which mycolate synthesis is coupled to transport, and the full MmpL3 transport machinery, is unknown. Here, we identify two new components of the MmpL3 transport machinery in mycobacteria. The protein encoded by MSMEG_0736/Rv0383c is essential for growth of Mycobacterium smegmatis and M. tuberculosis and is anchored to the cytoplasmic membrane, physically interacts with and colocalizes with MmpL3 in growing cells, and is required for trehalose monomycolate (TMM) transport to the cell wall. In light of these findings, we propose MSMEG_0736/Rv0383c be named "TMM transport factor A", TtfA. The protein encoded by MSMEG_5308 also interacts with the MmpL3 complex but is nonessential for growth or TMM transport. However, MSMEG_5308 accumulates with inhibition of MmpL3-mediated TMM transport and stabilizes the MmpL3/TtfA complex, indicating that it may stabilize the transport system during stress. These studies identify two new components of the mycobacterial mycolate transport machinery, an emerging antibiotic target in M. tuberculosis IMPORTANCE The cell envelope of Mycobacterium tuberculosis, the bacterium that causes the disease tuberculosis, is a complex structure composed of abundant lipids and glycolipids, including the signature lipid of these bacteria, mycolic acids. In this study, we identified two new components of the transport machinery that constructs this complex cell wall. These two accessory proteins are in a complex with the MmpL3 transporter. One of these proteins, TtfA, is required for mycolic acid transport and cell viability, whereas the other stabilizes the MmpL3 complex. These studies identify two new components of the essential cell envelope biosynthetic machinery in mycobacteria.
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26
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Advancing the Therapeutic Potential of Indoleamides for Tuberculosis. Antimicrob Agents Chemother 2019; 63:AAC.00343-19. [PMID: 31010860 PMCID: PMC6591635 DOI: 10.1128/aac.00343-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/12/2019] [Indexed: 12/18/2022] Open
Abstract
Indole-2-carboxamide derivatives are inhibitors of MmpL3, the cell wall-associated mycolic acid transporter of Mycobacterium tuberculosis. In the present study, we characterized indoleamide effects on bacterial cell morphology and reevaluated pharmacokinetics and in vivo efficacy using an optimized oral formulation. Indole-2-carboxamide derivatives are inhibitors of MmpL3, the cell wall-associated mycolic acid transporter of Mycobacterium tuberculosis. In the present study, we characterized indoleamide effects on bacterial cell morphology and reevaluated pharmacokinetics and in vivo efficacy using an optimized oral formulation. Morphologically, indoleamide-treated M. tuberculosis cells demonstrated significantly higher numbers of dimples near the poles or septum, which may serve as the mechanism of cell death for this bactericidal scaffold. Using the optimized formulation, an expanded-spectrum indoleamide, compound 2, showed significantly improved pharmacokinetic (PK) parameters and in vivo efficacy in mouse infection models. In a comparative study, compound 2 showed superior efficacy over compound 3 (NITD-304) in a high-dose aerosol mouse infection model. Since indoleamides are equally active on drug-resistant M. tuberculosis, these findings demonstrate the therapeutic potential of this novel scaffold for the treatment of both drug-susceptible and drug-resistant tuberculosis.
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27
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Li W, Stevens CM, Pandya AN, Darzynkiewicz Z, Bhattarai P, Tong W, Gonzalez-Juarrero M, North EJ, Zgurskaya HI, Jackson M. Direct Inhibition of MmpL3 by Novel Antitubercular Compounds. ACS Infect Dis 2019; 5:1001-1012. [PMID: 30882198 PMCID: PMC6580365 DOI: 10.1021/acsinfecdis.9b00048] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
MmpL3, an essential transporter involved in the export of mycolic acids, is the proposed target of a number of antimycobacterial inhibitors under development. Whether MmpL3 serves as the direct target of these compounds, however, has been called into question after the discovery that some of them dissipated the proton motive force from which MmpL transporters derive their energy. Using a combination of in vitro and whole-cell-based approaches, we here provide evidence that five structurally distinct MmpL3 inhibitor series, three of which impact proton motive force in Mycobacterium tuberculosis, directly interact with MmpL3. Medium- to high-throughput assays based on these approaches were developed to facilitate the future screening and optimization of MmpL3 inhibitors. The promiscuity of MmpL3 as a drug target and the mechanisms through which missense mutations located in a transmembrane region of this transporter may confer cross-resistance to a variety of chemical scaffolds are discussed in light of the exquisite vulnerability of MmpL3, its apparent mechanisms of interaction with inhibitors, and evidence of conformational changes induced both by the inhibitors and one of the most commonly identified resistance mutations in MmpL3.
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Affiliation(s)
- Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - Casey M. Stevens
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Amitkumar N. Pandya
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Zbigniew Darzynkiewicz
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Pankaj Bhattarai
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Weiwei Tong
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - Mercedes Gonzalez-Juarrero
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - E. Jeffrey North
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
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28
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Sequential assembly of the septal cell envelope prior to V snapping in Corynebacterium glutamicum. Nat Chem Biol 2019; 15:221-231. [PMID: 30664686 DOI: 10.1038/s41589-018-0206-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/27/2018] [Indexed: 12/11/2022]
Abstract
Members of the Corynebacterineae, including Corynebacterium and Mycobacterium, have an atypical cell envelope characterized by an additional mycomembrane outside of the peptidoglycan layer. How this multilayered cell envelope is assembled remains unclear. Here, we tracked the assembly dynamics of different envelope layers in Corynebacterium glutamicum and Mycobacterium smegmatis by using metabolic labeling and found that the septal cell envelope is assembled sequentially in both species. Additionally, we demonstrate that in C. glutamicum, the peripheral peptidoglycan layer at the septal junction remains contiguous throughout septation, forming a diffusion barrier for the fluid mycomembrane. This diffusion barrier is resolved through perforations in the peripheral peptidoglycan, thus leading to the confluency of the mycomembrane before daughter cell separation (V snapping). Furthermore, the same junctional peptidoglycan also serves as a mechanical link holding the daughter cells together and undergoes mechanical fracture during V snapping. Finally, we show that normal V snapping in C. glutamicum depends on complete assembly of the septal cell envelope.
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29
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Melzer ES, Sein CE, Chambers JJ, Siegrist MS. DivIVA concentrates mycobacterial cell envelope assembly for initiation and stabilization of polar growth. Cytoskeleton (Hoboken) 2018; 75:498-507. [PMID: 30160378 PMCID: PMC6644302 DOI: 10.1002/cm.21490] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/07/2018] [Accepted: 06/27/2018] [Indexed: 12/31/2022]
Abstract
In many model organisms, diffuse patterning of cell wall peptidoglycan synthesis by the actin homolog MreB enables the bacteria to maintain their characteristic rod shape. In Caulobacter crescentus and Escherichia coli, MreB is also required to sculpt this morphology de novo. Mycobacteria are rod-shaped but expand their cell wall from discrete polar or subpolar zones. In this genus, the tropomyosin-like protein DivIVA is required for the maintenance of cell morphology. DivIVA has also been proposed to direct peptidoglycan synthesis to the tips of the mycobacterial cell. The precise nature of this regulation is unclear, as is its role in creating rod shape from scratch. We find that DivIVA localizes nascent cell wall and covalently associated mycomembrane but is dispensable for the assembly process itself. Mycobacterium smegmatis rendered spherical by peptidoglycan digestion or by DivIVA depletion are able to regain rod shape at the population level in the presence of DivIVA. At the single cell level, there is a close spatiotemporal correlation between DivIVA foci, rod extrusion and concentrated cell wall synthesis. Thus, although the precise mechanistic details differ from other organisms, M. smegmatis also establish and propagate rod shape by cytoskeleton-controlled patterning of peptidoglycan. Our data further support the emerging notion that morphology is a hardwired trait of bacterial cells.
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Affiliation(s)
- Emily S Melzer
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
| | - Caralyn E Sein
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
| | - James J Chambers
- Institute for Applied Life Sciences, University of Massachusetts, Amherst, Massachusetts
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts.,Molecular and Cellular Biology, University of Massachusetts, Amherst, Massachusetts
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30
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García-Heredia A, Pohane AA, Melzer ES, Carr CR, Fiolek TJ, Rundell SR, Lim HC, Wagner JC, Morita YS, Swarts BM, Siegrist MS. Peptidoglycan precursor synthesis along the sidewall of pole-growing mycobacteria. eLife 2018; 7:37243. [PMID: 30198841 PMCID: PMC6191288 DOI: 10.7554/elife.37243] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 09/09/2018] [Indexed: 12/25/2022] Open
Abstract
Rod-shaped mycobacteria expand from their poles, yet d-amino acid probes label cell wall peptidoglycan in this genus at both the poles and sidewall. We sought to clarify the metabolic fates of these probes. Monopeptide incorporation was decreased by antibiotics that block peptidoglycan synthesis or l,d-transpeptidation and in an l,d-transpeptidase mutant. Dipeptides complemented defects in d-alanine synthesis or ligation and were present in lipid-linked peptidoglycan precursors. Characterizing probe uptake pathways allowed us to localize peptidoglycan metabolism with precision: monopeptide-marked l,d-transpeptidase remodeling and dipeptide-marked synthesis were coincident with mycomembrane metabolism at the poles, septum and sidewall. Fluorescent pencillin-marked d,d-transpeptidation around the cell perimeter further suggested that the mycobacterial sidewall is a site of cell wall assembly. While polar peptidoglycan synthesis was associated with cell elongation, sidewall synthesis responded to cell wall damage. Peptidoglycan editing along the sidewall may support cell wall robustness in pole-growing mycobacteria.
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Affiliation(s)
- Alam García-Heredia
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, United States
| | - Amol Arunrao Pohane
- Department of Microbiology, University of Massachusetts, Amherst, United States
| | - Emily S Melzer
- Department of Microbiology, University of Massachusetts, Amherst, United States
| | - Caleb R Carr
- Department of Microbiology, University of Massachusetts, Amherst, United States
| | - Taylor J Fiolek
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, United States
| | - Sarah R Rundell
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, United States
| | - Hoong Chuin Lim
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
| | - Jeffrey C Wagner
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, United States
| | - Yasu S Morita
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, United States.,Department of Microbiology, University of Massachusetts, Amherst, United States
| | - Benjamin M Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, United States
| | - M Sloan Siegrist
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, United States.,Department of Microbiology, University of Massachusetts, Amherst, United States
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31
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Rodriguez-Rivera FP, Zhou X, Theriot JA, Bertozzi CR. Acute Modulation of Mycobacterial Cell Envelope Biogenesis by Front-Line Tuberculosis Drugs. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201712020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Frances P. Rodriguez-Rivera
- Department of Chemistry; University of California; Berkeley CA 94720 USA
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
| | - Xiaoxue Zhou
- Department of Biochemistry; Stanford University School of Medicine; Stanford CA 94305 USA
| | - Julie A. Theriot
- Department of Biochemistry; Stanford University School of Medicine; Stanford CA 94305 USA
- Department of Microbiology and Immunology; Stanford University School of Medicine; Stanford CA 94305 USA
- Howard Hughes Medical Institute; Stanford University; Stanford CA 94305 USA
| | - Carolyn R. Bertozzi
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
- Howard Hughes Medical Institute; Stanford University; Stanford CA 94305 USA
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32
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Rodriguez-Rivera FP, Zhou X, Theriot JA, Bertozzi CR. Acute Modulation of Mycobacterial Cell Envelope Biogenesis by Front-Line Tuberculosis Drugs. Angew Chem Int Ed Engl 2018; 57:5267-5272. [PMID: 29392891 DOI: 10.1002/anie.201712020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/28/2018] [Indexed: 02/06/2023]
Abstract
Front-line tuberculosis (TB) drugs have been characterized extensively in vitro and in vivo with respect to gene expression and cell viability. However, little work has been devoted to understanding their effects on the physiology of the cell envelope, one of the main targets of this clinical regimen. Herein, we use metabolic labeling methods to visualize the effects of TB drugs on cell envelope dynamics in mycobacterial species. We developed a new fluorophore-trehalose conjugate to visualize trehalose monomycolates of the mycomembrane using super-resolution microscopy. We also probed the relationship between mycomembrane and peptidoglycan dynamics using a dual metabolic labeling strategy. Finally, we found that metabolic labeling of both cell envelope structures reports on drug effects on cell physiology in two hours, far faster than a genetic sensor of cell envelope stress. Our work provides insight into acute drug effects on cell envelope biogenesis in live mycobacteria.
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Affiliation(s)
- Frances P Rodriguez-Rivera
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.,Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Xiaoxue Zhou
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Julie A Theriot
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA, 94305, USA
| | - Carolyn R Bertozzi
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA.,Howard Hughes Medical Institute, Stanford University, Stanford, CA, 94305, USA
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33
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Ko CC, Hatfull GF. Mycobacteriophage Fruitloop gp52 inactivates Wag31 (DivIVA) to prevent heterotypic superinfection. Mol Microbiol 2018; 108:443-460. [PMID: 29488662 DOI: 10.1111/mmi.13946] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2018] [Indexed: 01/04/2023]
Abstract
Bacteriophages engage in complex dynamic interactions with their bacterial hosts and with each other. Bacteria have numerous mechanisms to resist phage infection, and phages must co-evolve by overcoming bacterial resistance or by choosing an alternative host. Phages also compete with each other, both during lysogeny by prophage-mediated defense against viral attack and by superinfection exclusion during lytic replication. Phages are enormously diverse genetically and are replete with small genes of unknown function, many of which are not required for lytic growth, but which may modulate these bacteria-phage and phage-phage dynamics. Using cellular toxicity of phage gene overexpression as an assay, we identified the 93-residue protein gp52 encoded by Cluster F mycobacteriophage Fruitloop. The toxicity of Fruitloop gp52 overexpression results from interaction with and inactivation of Wag31 (DivIVA), an essential Mycobacterium smegmatis protein organizing cell wall biosynthesis at the growing cellular poles. Fruitloop gene 52 is expressed early in lytic growth and is not required for normal Fruitloop lytic replication but interferes with Subcluster B2 phages such as Hedgerow and Rosebush. We conclude that Hedgerow and Rosebush are Wag31-dependent phages and that Fruitloop gp52 confers heterotypic superinfection exclusion by inactivating Wag31.
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Affiliation(s)
- Ching-Chung Ko
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Graham F Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA
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34
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Puffal J, García-Heredia A, Rahlwes KC, Siegrist MS, Morita YS. Spatial control of cell envelope biosynthesis in mycobacteria. Pathog Dis 2018; 76:4953754. [DOI: 10.1093/femspd/fty027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/25/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Julia Puffal
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Alam García-Heredia
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
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35
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Cole ST. Inhibiting Mycobacterium tuberculosis within and without. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0506. [PMID: 27672155 DOI: 10.1098/rstb.2015.0506] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2016] [Indexed: 01/05/2023] Open
Abstract
Tuberculosis remains a scourge of global health with shrinking treatment options due to the spread of drug-resistant strains of Mycobacterium tuberculosis Intensive efforts have been made in the past 15 years to find leads for drug development so that better, more potent drugs inhibiting new targets could be produced and thus shorten treatment duration. Initial attempts focused on repurposing drugs that had been developed for other therapeutic areas but these agents did not meet their goals in clinical trials. Attempts to find new lead compounds employing target-based screens were unsuccessful as the leads were inactive against M. tuberculosis Greater success was achieved using phenotypic screening against live tubercle bacilli and this gave rise to the drugs bedaquiline, pretomanid and delamanid, currently in phase III trials. Subsequent phenotypic screens also uncovered new leads and targets but several of these targets proved to be promiscuous and inhibited by a variety of seemingly unrelated pharmacophores. This setback sparked an interest in alternative screening approaches that mimic the disease state more accurately. Foremost among these were cell-based screens, often involving macrophages, as these should reflect the bacterium's niche in the host more faithfully. A major advantage of this approach is its ability to uncover functions that are central to infection but not necessarily required for growth in vitro For instance, inhibition of virulence functions mediated by the ESX-1 secretion system severely attenuates intracellular M. tuberculosis, preventing intercellular spread and ultimately limiting tissue damage. Cell-based screens have highlighted the druggability of energy production via the electron transport chain and cholesterol metabolism. Here, I review the scientific progress and the pipeline, but warn against over-optimism due to the lack of industrial commitment for tuberculosis drug development and other socio-economic factors.This article is part of the themed issue 'The new bacteriology'.
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Affiliation(s)
- Stewart T Cole
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne, Station 19, 1015 Lausanne, Switzerland
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Distinct Spatiotemporal Dynamics of Peptidoglycan Synthesis between Mycobacterium smegmatis and Mycobacterium tuberculosis. mBio 2017; 8:mBio.01183-17. [PMID: 28900018 PMCID: PMC5596344 DOI: 10.1128/mbio.01183-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Peptidoglycan (PG), a polymer cross-linked by d-amino acid-containing peptides, is an essential component of the bacterial cell wall. We found that a fluorescent d-alanine analog (FDAA) incorporates chiefly at one of the two poles in Mycobacterium smegmatis but that polar dominance varies as a function of the cell cycle in Mycobacterium tuberculosis: immediately after cytokinesis, FDAAs are incorporated chiefly at one of the two poles, but just before cytokinesis, FDAAs are incorporated comparably at both. These observations suggest that mycobacterial PG-synthesizing enzymes are localized in functional compartments at the poles and septum and that the capacity for PG synthesis matures at the new pole in M. tuberculosis Deeper knowledge of the biology of mycobacterial PG synthesis may help in discovering drugs that disable previously unappreciated steps in the process.IMPORTANCE People are dying all over the world because of the rise of antimicrobial resistance to medicines that could previously treat bacterial infections, including tuberculosis. Here, we used fluorescent d-alanine analogs (FDAAs) that incorporate into peptidoglycan (PG)-the synthesis of which is an attractive drug target-combined with high- and super-resolution microscopy to investigate the spatiotemporal dynamics of PG synthesis in M. smegmatis and M. tuberculosis FDAA incorporation predominates at one of the two poles in M. smegmatis In contrast, while FDAA incorporation into M. tuberculosis is also polar, there are striking variations in polar dominance as a function of the cell cycle. This suggests that enzymes involved in PG synthesis are localized in functional compartments in mycobacteria and that M. tuberculosis possesses a mechanism for maturation of the capacity for PG synthesis at the new pole. This may help in discovering drugs that cripple previously unappreciated steps in the process.
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37
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Abstract
Mycobacterial 6-kDa early secreted antigenic target (ESAT-6) system (ESX) exporters transport proteins across the cytoplasmic membrane. Many proteins transported by ESX systems are then translocated across the mycobacterial cell envelope and secreted from the cell. Although the mechanism underlying protein transport across the mycolate outer membrane remains elusive, the ESX systems are closely connected with and localize to the cell envelope. Links between ESX-associated proteins, cell wall synthesis, and the maintenance of cell envelope integrity have been reported. Genes encoding the ESX systems and those required for biosynthesis of the mycobacterial envelope are coregulated. Here, we review the interplay between ESX systems and the mycobacterial cell envelope.
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38
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Abstract
The interaction between the host and the pathogen is extremely complex and is affected by anatomical, physiological, and immunological diversity in the microenvironments, leading to phenotypic diversity of the pathogen. Phenotypic heterogeneity, defined as nongenetic variation observed in individual members of a clonal population, can have beneficial consequences especially in fluctuating stressful environmental conditions. This is all the more relevant in infections caused by Mycobacterium tuberculosis wherein the pathogen is able to survive and often establish a lifelong persistent infection in the host. Recent studies in tuberculosis patients and in animal models have documented the heterogeneous and diverging trajectories of individual lesions within a single host. Since the fate of the individual lesions appears to be determined by the local tissue environment rather than systemic response of the host, studying this heterogeneity is very relevant to ensure better control and complete eradication of the pathogen from individual lesions. The heterogeneous microenvironments greatly enhance M. tuberculosis heterogeneity influencing the growth rates, metabolic potential, stress responses, drug susceptibility, and eventual lesion resolution. Single-cell approaches such as time-lapse microscopy using microfluidic devices allow us to address cell-to-cell variations that are often lost in population-average measurements. In this review, we focus on some of the factors that could be considered as drivers of phenotypic heterogeneity in M. tuberculosis as well as highlight some of the techniques that are useful in addressing this issue.
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Touchette MH, Van Vlack ER, Bai L, Kim J, Cognetta AB, Previti ML, Backus KM, Martin DW, Cravatt BF, Seeliger JC. A Screen for Protein-Protein Interactions in Live Mycobacteria Reveals a Functional Link between the Virulence-Associated Lipid Transporter LprG and the Mycolyltransferase Antigen 85A. ACS Infect Dis 2017; 3:336-348. [PMID: 28276676 DOI: 10.1021/acsinfecdis.6b00179] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Outer membrane lipids in pathogenic mycobacteria are important for virulence and survival. Although the biosynthesis of these lipids has been extensively studied, mechanisms responsible for their assembly in the outer membrane are not understood. In the study of Gram-negative outer membrane assembly, protein-protein interactions define transport mechanisms, but analogous interactions have not been explored in mycobacteria. Here we identified interactions with the lipid transport protein LprG. Using site-specific photo-cross-linking in live mycobacteria, we mapped three major interaction interfaces within LprG. We went on to identify proteins that cross-link at the entrance to the lipid binding pocket, an area likely relevant to LprG transport function. We verified LprG site-specific interactions with two hits, the conserved lipoproteins LppK and LppI. We further showed that LprG interacts physically and functionally with the mycolyltransferase Ag85A, as loss of either protein leads to similar defects in cell growth and mycolylation. Overall, our results support a model in which protein interactions coordinate multiple pathways in outer membrane biogenesis and connect lipid biosynthesis to transport.
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Affiliation(s)
- Megan H. Touchette
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Erik R. Van Vlack
- Department of Chemistry, Stony Brook University, Stony
Brook, New York 11790, United States
| | - Lu Bai
- Department of Chemistry, Stony Brook University, Stony
Brook, New York 11790, United States
| | - Jia Kim
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Armand B. Cognetta
- Department of Chemical Physiology, The
Skaggs Institute for Chemical Biology, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - Mary L. Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Keriann M. Backus
- Department of Chemical Physiology, The
Skaggs Institute for Chemical Biology, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - Dwight W. Martin
- Department of Medicine, Stony Brook University, Stony
Brook, New York 11794, United States
- Proteomics Center, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Benjamin F. Cravatt
- Department of Chemical Physiology, The
Skaggs Institute for Chemical Biology, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
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40
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Viljoen A, Dubois V, Girard-Misguich F, Blaise M, Herrmann JL, Kremer L. The diverse family of MmpL transporters in mycobacteria: from regulation to antimicrobial developments. Mol Microbiol 2017; 104:889-904. [DOI: 10.1111/mmi.13675] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Albertus Viljoen
- Institut de Recherche en Infectiologie de Montpellier (IRIM); CNRS, UMR 9004, Université de Montpellier, France
| | - Violaine Dubois
- INSERM, UMR1173; Université de Versailles Saint-Quentin-en-Yvelines; Montigny-le-Bretonneux 78180 France
| | - Fabienne Girard-Misguich
- INSERM, UMR1173; Université de Versailles Saint-Quentin-en-Yvelines; Montigny-le-Bretonneux 78180 France
| | - Mickaël Blaise
- Institut de Recherche en Infectiologie de Montpellier (IRIM); CNRS, UMR 9004, Université de Montpellier, France
| | - Jean-Louis Herrmann
- INSERM, UMR1173; Université de Versailles Saint-Quentin-en-Yvelines; Montigny-le-Bretonneux 78180 France
| | - Laurent Kremer
- Institut de Recherche en Infectiologie de Montpellier (IRIM); CNRS, UMR 9004, Université de Montpellier, France
- IRIM; INSERM; 34293 Montpellier France
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41
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Rodriguez-Rivera FP, Zhou X, Theriot JA, Bertozzi CR. Visualization of mycobacterial membrane dynamics in live cells. J Am Chem Soc 2017; 139:3488-3495. [PMID: 28075574 PMCID: PMC5345120 DOI: 10.1021/jacs.6b12541] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mycobacteria are endowed with a highly impermeable mycomembrane that confers intrinsic resistance to many antibiotics. Several unique mycomembrane glycolipids have been isolated and structurally characterized, but the underlying organization and dynamics of glycolipids within the cell envelope remain poorly understood. We report here a study of mycomembrane dynamics that was enabled by trehalose-fluorophore conjugates capable of labeling trehalose glycolipids in live actinomycetes. We identified fluorescein-trehalose analogues that are metabolically incorporated into the trehalose mycolates of representative Mycobacterium, Corynebacterium, Nocardia, and Rhodococcus species. Using these probes, we studied the mobilities of labeled glycolipids by time-lapse microscopy and fluorescence recovery after photobleaching experiments and found that mycomembrane fluidity varies widely across species and correlates with mycolic acid structure. Finally, we discovered that treatment of mycobacteria with ethambutol, a front-line tuberculosis (TB) drug, significantly increases mycomembrane fluidity. These findings enhance our understanding of mycobacterial cell envelope structure and dynamics and have implications for development of TB drug cocktails.
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Affiliation(s)
- Frances P Rodriguez-Rivera
- Department of Chemistry, University of California , Berkeley, California 94720, United States.,Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | | | - Julie A Theriot
- Howard Hughes Medical Institute , Chevy Chase, Maryland 20815, United States
| | - Carolyn R Bertozzi
- Department of Chemistry, Stanford University , Stanford, California 94305, United States.,Howard Hughes Medical Institute , Chevy Chase, Maryland 20815, United States
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42
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McLean KJ, Munro AW. Drug targeting of heme proteins in Mycobacterium tuberculosis. Drug Discov Today 2016; 22:566-575. [PMID: 27856345 DOI: 10.1016/j.drudis.2016.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 10/28/2016] [Accepted: 11/02/2016] [Indexed: 01/08/2023]
Abstract
TB, caused by the human pathogen Mycobacterium tuberculosis (Mtb), causes more deaths than any other infectious disease. Iron is crucial for Mtb to infect the host and to sustain infection, with Mtb encoding large numbers of iron-binding proteins. Many of these are hemoproteins with key roles, including defense against oxidative stress, cellular signaling and regulation, host cholesterol metabolism, and respiratory processes. Various heme enzymes in Mtb are validated drug targets and/or products of genes essential for bacterial viability or survival in the host. Here, we review the structure, function, and druggability of key Mtb heme enzymes and strategies used for their inhibition.
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Affiliation(s)
- Kirsty J McLean
- School of Chemistry, The University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK
| | - Andrew W Munro
- School of Chemistry, The University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, UK.
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43
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Belardinelli JM, Yazidi A, Yang L, Fabre L, Li W, Jacques B, Angala SK, Rouiller I, Zgurskaya HI, Sygusch J, Jackson M. Structure-Function Profile of MmpL3, the Essential Mycolic Acid Transporter from Mycobacterium tuberculosis. ACS Infect Dis 2016; 2:702-713. [PMID: 27737557 DOI: 10.1021/acsinfecdis.6b00095] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The MmpL family of proteins translocates complex (glyco)lipids and siderophores across the cell envelope of mycobacteria and closely related Corynebacteriaceae and plays important roles in the biogenesis of the outer membrane of these organisms. Despite their significance in the physiology and virulence of Mycobacterium tuberculosis, and from the perspective of developing novel antituberculosis agents, little is known about their structure and mechanism of translocation. In this study, the essential mycobacterial mycolic acid transporter, MmpL3, and its orthologue in Corynebacterium glutamicum, CmpL1, were investigated as prototypical MmpL proteins to gain insight into the transmembrane topology, tertiary and quaternary structures, and functional regions of this transporter family. The combined genetic, biochemical, and biophysical studies indicate that MmpL3 and CmpL1 are structurally similar to Gram-negative resistance-nodulation and division efflux pumps. They harbor 12 transmembrane segments interrupted by two large soluble periplasmic domains and function as homotrimers to export long-chain (C22-C90) mycolic acids, possibly in their acetylated form, esterified to trehalose. The mapping of a number of functional residues within the middle region of the transmembrane domain of MmpL3 shows a striking overlap with mutations associated with resistance to MmpL3 inhibitors. The results suggest that structurally diverse inhibitors of MmpL3 all target the proton translocation path of the transporter and that multiresistance to these inhibitors is enabled by conformational changes in MmpL3.
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Affiliation(s)
- Juan Manuel Belardinelli
- Mycobacteria
Research Laboratories, Department of Microbiology, Immunology and
Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States
| | - Amira Yazidi
- Biochimie et Médecine Moléculaire, Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
- Groupe d’Étude des Protéines Membranaires
(GÉPROM), Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Liang Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Lucien Fabre
- Groupe d’Étude des Protéines Membranaires
(GÉPROM), Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montréal, Quebec H3A 2B2, Canada
| | - Wei Li
- Mycobacteria
Research Laboratories, Department of Microbiology, Immunology and
Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States
| | - Benoit Jacques
- Biochimie et Médecine Moléculaire, Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Shiva kumar Angala
- Mycobacteria
Research Laboratories, Department of Microbiology, Immunology and
Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States
| | - Isabelle Rouiller
- Groupe d’Étude des Protéines Membranaires
(GÉPROM), Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
- Department of Anatomy and Cell Biology, McGill University, 3640 University Street, Montréal, Quebec H3A 2B2, Canada
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Jurgen Sygusch
- Biochimie et Médecine Moléculaire, Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
- Groupe d’Étude des Protéines Membranaires
(GÉPROM), Université de Montréal, CP 6128, Station Centre-Ville, Montréal, Quebec H3C 3J7, Canada
| | - Mary Jackson
- Mycobacteria
Research Laboratories, Department of Microbiology, Immunology and
Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, United States
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44
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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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45
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Chalut C. MmpL transporter-mediated export of cell-wall associated lipids and siderophores in mycobacteria. Tuberculosis (Edinb) 2016; 100:32-45. [DOI: 10.1016/j.tube.2016.06.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/23/2016] [Indexed: 10/21/2022]
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46
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Therapeutic Potential of the Mycobacterium tuberculosis Mycolic Acid Transporter, MmpL3. Antimicrob Agents Chemother 2016; 60:5198-207. [PMID: 27297488 DOI: 10.1128/aac.00826-16] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/08/2016] [Indexed: 11/20/2022] Open
Abstract
In recent years, whole-cell-based screens for novel small molecule inhibitors active against Mycobacterium tuberculosis in culture followed by the whole-genome sequencing of spontaneous resistant mutants have identified multiple chemical scaffolds thought to kill the bacterium through the inactivation of the mycolic acid transporter, MmpL3. Consistent with the fact that MmpL3 is required for the formation of the mycobacterial outer membrane, we have conclusively shown in this study, using conditionally regulated knockdown mutants, that mmpL3 is required for the replication and viability of M. tuberculosis, both under standard laboratory growth conditions and during the acute and chronic phases of infection in mice. Speaking for the vulnerability of this target, silencing mmpL3 had a rapid bactericidal effect on actively replicating cells in vitro and reduced by 3 to 5 logs in less than 4 weeks the bacterial loads of acutely and chronically infected mouse lungs, respectively. Depletion of MmpL3 further rendered M. tuberculosis hypersusceptible to MmpL3 inhibitors. The exquisite vulnerability of MmpL3 at all stages of the infection establishes this transporter as an attractive new target with the potential to improve and shorten current drug-susceptible and drug-resistant tuberculosis chemotherapies.
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47
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Touchette MH, Bommineni GR, Delle Bovi RJ, Gadbery JE, Nicora CD, Shukla AK, Kyle JE, Metz TO, Martin DW, Sampson NS, Miller WT, Tonge PJ, Seeliger JC. Diacyltransferase Activity and Chain Length Specificity of Mycobacterium tuberculosis PapA5 in the Synthesis of Alkyl β-Diol Lipids. Biochemistry 2015; 54:5457-68. [PMID: 26271001 DOI: 10.1021/acs.biochem.5b00455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although they are classified as Gram-positive bacteria, Corynebacterineae possess an asymmetric outer membrane that imparts structural and thereby physiological similarity to more distantly related Gram-negative bacteria. Like lipopolysaccharide in Gram-negative bacteria, lipids in the outer membrane of Corynebacterineae have been associated with the virulence of pathogenic species such as Mycobacterium tuberculosis (Mtb). For example, Mtb strains that lack long, branched-chain alkyl esters known as dimycocerosates (DIMs) are significantly attenuated in model infections. The resultant interest in the biosynthetic pathway of these unusual virulence factors has led to the elucidation of many of the steps leading to the final esterification of the alkyl β-diol, phthiocerol, with branched-chain fatty acids known as mycocerosates. PapA5 is an acyltransferase implicated in these final reactions. Here, we show that PapA5 is indeed the terminal enzyme in DIM biosynthesis by demonstrating its dual esterification activity and chain-length preference using synthetic alkyl β-diol substrate analogues. By applying these analogues to a series of PapA5 mutants, we also revise a model for the substrate binding within PapA5. Finally, we demonstrate that the Mtb Ser/Thr kinases PknB and PknE modify PapA5 on three overlapping Thr residues and that a fourth Thr is unique to PknE phosphorylation. These results clarify the DIM biosynthetic pathway and indicate post-translational modifications that warrant further elucidation for their roles in the regulation of DIM biosynthesis.
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Affiliation(s)
| | | | | | | | - Carrie D Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Anil K Shukla
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Jennifer E Kyle
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Thomas O Metz
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
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48
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Chim N, Torres R, Liu Y, Capri J, Batot G, Whitelegge JP, Goulding CW. The Structure and Interactions of Periplasmic Domains of Crucial MmpL Membrane Proteins from Mycobacterium tuberculosis. ACTA ACUST UNITED AC 2015; 22:1098-107. [PMID: 26278184 DOI: 10.1016/j.chembiol.2015.07.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 06/25/2015] [Accepted: 07/13/2015] [Indexed: 11/29/2022]
Abstract
Mycobacterium tuberculosis mycobacterial membrane protein large (MmpL) proteins are important in substrate transport across the inner membrane. Here, we show that MmpL proteins are classified into two phylogenetic clusters, where MmpL cluster II contains three soluble domains (D1, D2, and D3) and has two full-length members, MmpL3 and MmpL11. Significantly, MmpL3 is currently the most druggable M. tuberculosis target. We have solved the 2.4-Å MmpL11-D2 crystal structure, revealing structural homology to periplasmic porter subdomains of RND (multidrug) transporters. The resulting predicted cluster II MmpL membrane topology has D1 and D2 residing, and possibly interacting, within the periplasm. Crosslinking and biolayer interferometry experiments confirm that cluster II D1 and D2 bind with weak affinities, and guided D1-D2 heterodimeric model assemblies. The predicted full-length MmpL3 and MmpL11 structural models reveal key substrate binding and transport residues, and may serve as templates to set the stage for in silico anti-tuberculosis drug development.
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Affiliation(s)
- Nicholas Chim
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Rodrigo Torres
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Yuqi Liu
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Joe Capri
- The Pasarow Mass Spectrometry Laboratory, NPI-Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA 90024, USA
| | - Gaëlle Batot
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Julian P Whitelegge
- The Pasarow Mass Spectrometry Laboratory, NPI-Semel Institute, David Geffen School of Medicine, UCLA, Los Angeles, CA 90024, USA
| | - Celia W Goulding
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA; Department of Pharmaceutical Sciences, UCI, Irvine, CA 92697, USA.
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49
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Bailo R, Bhatt A, Aínsa JA. Lipid transport in Mycobacterium tuberculosis and its implications in virulence and drug development. Biochem Pharmacol 2015; 96:159-67. [DOI: 10.1016/j.bcp.2015.05.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/05/2015] [Indexed: 11/26/2022]
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50
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Nataraj V, Varela C, Javid A, Singh A, Besra GS, Bhatt A. Mycolic acids: deciphering and targeting the Achilles' heel of the tubercle bacillus. Mol Microbiol 2015; 98:7-16. [PMID: 26135034 PMCID: PMC4949712 DOI: 10.1111/mmi.13101] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2015] [Indexed: 12/31/2022]
Abstract
Mycolic acids are unique long chain fatty acids found in the lipid-rich cell walls of mycobacteria including the tubercle bacillus Mycobacterium tuberculosis. Essential for viability and virulence, enzymes involved in the biosynthesis of mycolic acids represent novel targets for drug development. This is particularly relevant to the impact on global health given the rise of multidrug resistant and extensively drug resistant strains of M. tuberculosis. In this review, we discuss recent advances in our understanding of how mycolic acid are synthesised, especially the potential role of specialised fatty acid synthase complexes. Also, we examine the role of a recently reported mycolic acid transporter MmpL3 with reference to several reports of the targeting of this transporter by diverse compounds with anti-M. tuberculosis activity. Additionally, we consider recent findings that place mycolic acid biosynthesis in the context of the cell biology of the bacterium, viz its localisation and co-ordination with the bacterial cytoskeleton, and its role beyond maintaining cell envelope integrity.
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Affiliation(s)
- Vijayashankar Nataraj
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Cristian Varela
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Asma Javid
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Albel Singh
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Gurdyal S Besra
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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