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Lee SY, Marando VM, Smelyansky SR, Kim DE, Calabretta PJ, Warner TC, Bryson BD, Kiessling LL. Selective Glycan Labeling of Mannose-Containing Glycolipids in Mycobacteria. J Am Chem Soc 2024; 146:377-385. [PMID: 38112296 PMCID: PMC10914408 DOI: 10.1021/jacs.3c09495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Mycobacterium tuberculosis (Mtb) is one of history's most successful human pathogens. By subverting typical immune responses, Mtb can persist within a host until conditions become favorable for growth and proliferation. Virulence factors that enable mycobacteria to modulate host immune systems include a suite of mannose-containing glycolipids: phosphatidylinositol mannosides, lipomannan, and lipoarabinomannan (LAM). Despite their importance, tools for their covalent capture, modification, and imaging are limited. Here, we describe a chemical biology strategy to detect and visualize these glycans. Our approach, biosynthetic incorporation, is to synthesize a lipid-glycan precursor that can be incorporated at a late-stage step in glycolipid biosynthesis. We previously demonstrated selective mycobacterial arabinan modification by biosynthetic incorporation using an exogenous donor. This report reveals that biosynthetic labeling is general and selective: it allows for cell surface mannose-containing glycolipid modification without nonspecific labeling of mannosylated glycoproteins. Specifically, we employed azido-(Z,Z)-farnesyl phosphoryl-β-d-mannose probes and took advantage of the strain-promoted azide-alkyne cycloaddition to label and directly visualize the localization and dynamics of mycobacterial mannose-containing glycolipids. Our studies highlight the generality and utility of biosynthetic incorporation as the probe structure directs the selective labeling of distinct glycans. The disclosed agents allowed for direct tracking of the target immunomodulatory glycolipid dynamics in cellulo. We anticipate that these probes will facilitate investigating the diverse biological roles of these glycans.
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Affiliation(s)
- So Young Lee
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Victoria M. Marando
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Stephanie R. Smelyansky
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Daria E. Kim
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Phillip J. Calabretta
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, University of Wisconsin Madison, Madison, Wisconsin 53706, United States
| | - Theodore C. Warner
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Bryan D. Bryson
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts 02139, USA
| | - Laura L. Kiessling
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, University of Wisconsin Madison, Madison, Wisconsin 53706, United States
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts 02139, USA
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2
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Rahlwes KC, Dias BR, Campos PC, Alvarez-Arguedas S, Shiloh MU. Pathogenicity and virulence of Mycobacterium tuberculosis. Virulence 2023; 14:2150449. [PMID: 36419223 PMCID: PMC9817126 DOI: 10.1080/21505594.2022.2150449] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, an infectious disease with one of the highest morbidity and mortality rates worldwide. Leveraging its highly evolved repertoire of non-protein and protein virulence factors, Mtb invades through the airway, subverts host immunity, establishes its survival niche, and ultimately escapes in the setting of active disease to initiate another round of infection in a naive host. In this review, we will provide a concise synopsis of the infectious life cycle of Mtb and its clinical and epidemiologic significance. We will also take stock of its virulence factors and pathogenic mechanisms that modulate host immunity and facilitate its spread. Developing a greater understanding of the interface between Mtb virulence factors and host defences will enable progress toward improved vaccines and therapeutics to prevent and treat tuberculosis.
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Affiliation(s)
- Kathryn C. Rahlwes
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Beatriz R.S. Dias
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Priscila C. Campos
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Samuel Alvarez-Arguedas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Michael U. Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA,Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA,CONTACT Michael U. Shiloh
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Sparks IL, Nijjer J, Yan J, Morita YS. Lipoarabinomannan regulates septation in Mycobacterium smegmatis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.26.534150. [PMID: 36993273 PMCID: PMC10055410 DOI: 10.1101/2023.03.26.534150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The growth and division of mycobacteria, which include several clinically relevant pathogens, deviate significantly from that of canonical bacterial models. Despite their Gram-positive ancestry, mycobacteria synthesize and elongate a diderm envelope asymmetrically from the poles, with the old pole elongating more robustly than the new pole. In addition to being structurally distinct, the molecular components of the mycobacterial envelope are also evolutionarily unique, including the phosphatidylinositol-anchored lipoglycans lipomannan (LM) and lipoarabinomannan (LAM). LM and LAM modulate host immunity during infection, but their role outside of intracellular survival remains poorly understood, despite their widespread conservation among non-pathogenic and opportunistically pathogenic mycobacteria. Previously, Mycobacterium smegmatis and Mycobacterium tuberculosis mutants producing structurally altered LM and LAM were shown to grow slowly under certain conditions and to be more sensitive to antibiotics, suggesting that mycobacterial lipoglycans may support cellular integrity or growth. To test this, we constructed multiple biosynthetic lipoglycan mutants of M. smegmatis and determined the effect of each mutation on cell wall biosynthesis, envelope integrity, and division. We found that mutants deficient in LAM, but not LM, fail to maintain cell wall integrity in a medium-dependent manner, with envelope deformations specifically associated with septa and new poles. Conversely, a mutant producing abnormally large LAM formed multiseptated cells in way distinct from that observed in a septal hydrolase mutant. These results show that LAM plays critical and distinct roles at subcellular locations associated with division in mycobacteria, including maintenance of local cell envelope integrity and septal placement.
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Affiliation(s)
- Ian L. Sparks
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Japinder Nijjer
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven CT, USA
- Quantitative Biology Institute, Yale University, New Haven, CT, USA
| | - Jing Yan
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven CT, USA
- Quantitative Biology Institute, Yale University, New Haven, CT, USA
| | - Yasu S. Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
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4
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Hodges H, Obeng K, Avanzi C, Ausmus AP, Angala SK, Kalera K, Palcekova Z, Swarts BM, Jackson M. Azido Inositol Probes Enable Metabolic Labeling of Inositol-Containing Glycans and Reveal an Inositol Importer in Mycobacteria. ACS Chem Biol 2023; 18:595-604. [PMID: 36856664 PMCID: PMC10071489 DOI: 10.1021/acschembio.2c00912] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Bacteria from the genus Mycobacterium include pathogens that cause serious diseases in humans and remain as difficult infectious agents to treat. Central to these challenges are the composition and organization of the mycobacterial cell envelope, which includes unique and complex glycans. Inositol is an essential metabolite for mycobacteria due to its presence in the structural core of the immunomodulatory cell envelope glycolipids phosphatidylinositol mannoside (PIM) and PIM-anchored lipomannan (LM) and lipoarabinomannan (LAM). Despite their importance to mycobacterial physiology and pathogenesis, many aspects of PIM, LM, and LAM construction and dynamics remain poorly understood. Recently, probes that allow metabolic labeling and detection of specific mycobacterial glycans have been developed to investigate cell envelope assembly and dynamics. However, these tools have been limited to peptidoglycan, arabinogalactan, and mycolic acid-containing glycolipids. Herein, we report the development of synthetic azido inositol (InoAz) analogues as probes that can metabolically label PIMs, LM, and LAM in intact mycobacteria. Additionally, we leverage an InoAz probe to discover an inositol importer and catabolic pathway in Mycobacterium smegmatis. We anticipate that in the future, InoAz probes, in combination with bioorthogonal chemistry, will provide a valuable tool for investigating PIM, LM, and LAM biosynthesis, transport, and dynamics in diverse mycobacterial organisms.
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Affiliation(s)
- Heather Hodges
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523 USA
| | - Kwaku Obeng
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, 48859 USA
| | - Charlotte Avanzi
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523 USA
| | - Alex P. Ausmus
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, 48859 USA
| | - Shiva Kumar Angala
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523 USA
| | - Karishma Kalera
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, 48859 USA
- Biochemistry, Cellular, and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI, 48859 USA
| | - Zuzana Palcekova
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523 USA
| | - Benjamin M. Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, 48859 USA
- Biochemistry, Cellular, and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI, 48859 USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523 USA
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Physiological, Biochemical, and Structural Bioinformatic Analysis of the Multiple Inositol Dehydrogenases from Corynebacterium glutamicum. Microbiol Spectr 2022; 10:e0195022. [PMID: 36094194 PMCID: PMC9603128 DOI: 10.1128/spectrum.01950-22] [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] [Indexed: 12/31/2022] Open
Abstract
Inositols (cyclohexanehexols) comprise nine isomeric cyclic sugar alcohols, several of which occur in all domains of life with various functions. Many bacteria can utilize inositols as carbon and energy sources via a specific pathway involving inositol dehydrogenases (IDHs) as the first step of catabolism. The microbial cell factory Corynebacterium glutamicum can grow with myo-inositol as a sole carbon source. Interestingly, this species encodes seven potential IDHs, raising the question of the reason for this multiplicity. We therefore investigated the seven IDHs to determine their function, activity, and selectivity toward the biologically most important isomers myo-, scyllo-, and d-chiro-inositol. We created an ΔIDH strain lacking all seven IDH genes, which could not grow on the three inositols. scyllo- and d-chiro-inositol were identified as novel growth substrates of C. glutamicum. Complementation experiments showed that only four of the seven IDHs (IolG, OxiB, OxiD, and OxiE) enabled growth of the ΔIDH strain on two of the three inositols. The kinetics of the four purified enzymes agreed with the complementation results. IolG and OxiD are NAD+-dependent IDHs accepting myo- and d-chiro-inositol but not scyllo-inositol. OxiB is an NAD+-dependent myo-IDH with a weak activity also for scyllo-inositol but not for d-chiro-inositol. OxiE on the other hand is an NAD+-dependent scyllo-IDH showing also good activity for myo-inositol and a very weak activity for d-chiro-inositol. Structural models, molecular docking experiments, and sequence alignments enabled the identification of the substrate binding sites of the active IDHs and of residues allowing predictions on the substrate specificity. IMPORTANCE myo-, scyllo-, and d-chiro-inositol are C6 cyclic sugar alcohols with various biological functions, which also serve as carbon sources for microbes. Inositol catabolism starts with an oxidation to keto-inositols catalyzed by inositol dehydrogenases (IDHs). The soil bacterium C. glutamicum encodes seven potential IDHs. Using a combination of microbiological, biochemical, and modeling approaches, we analyzed the function of these enzymes and identified four IDHs involved in the catabolism of inositols. They possess distinct substrate preferences for the three isomers, and modeling and sequence alignments allowed the identification of residues important for substrate specificity. Our results expand the knowledge of bacterial inositol metabolism and provide an important basis for the rational development of producer strains for these valuable inositols, which show pharmacological activities against, e.g., Alzheimer's disease, polycystic ovarian syndrome, or type II diabetes.
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6
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Nguyen PP, Kado T, Prithviraj M, Siegrist MS, Morita YS. Inositol acylation of phosphatidylinositol mannosides: a rapid mass response to membrane fluidization in mycobacteria. J Lipid Res 2022; 63:100262. [PMID: 35952902 PMCID: PMC9490103 DOI: 10.1016/j.jlr.2022.100262] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 07/25/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
Mycobacteria share an unusually complex, multilayered cell envelope, which contributes to adaptation to changing environments. The plasma membrane is the deepest layer of the cell envelope and acts as the final permeability barrier against outside molecules. There is an obvious need to maintain the plasma membrane integrity, but the adaptive responses of the plasma membrane to stress exposure remain poorly understood. Using chemical treatment and heat stress to fluidize the membrane, we show here that phosphatidylinositol (PI)-anchored plasma membrane glycolipids known as PI mannosides (PIMs) are rapidly remodeled upon membrane fluidization in Mycobacterium smegmatis. Without membrane stress, PIMs are predominantly in a triacylated form: two acyl chains of the PI moiety plus one acyl chain modified at one of the mannose residues. Upon membrane fluidization, we determined the fourth fatty acid is added to the inositol moiety of PIMs, making them tetra-acylated variants. Additionally, we show that PIM inositol acylation is a rapid response independent of de novo protein synthesis, representing one of the fastest mass conversions of lipid molecules found in nature. Strikingly, we found that M. smegmatis is more resistant to the bactericidal effect of a cationic detergent after benzyl alcohol pre-exposure. We further demonstrate that fluidization-induced PIM inositol acylation is conserved in pathogens such as Mycobacterium tuberculosis and Mycobacterium abscessus. Our results demonstrate that mycobacteria possess a mechanism to sense plasma membrane fluidity change. We suggest that inositol acylation of PIMs is a novel membrane stress response that enables mycobacterial cells to resist membrane fluidization.
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Affiliation(s)
- Peter P Nguyen
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Takehiro Kado
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | | | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA; Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA; Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA, USA.
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7
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Characterization of inositol lipid metabolism in gut-associated Bacteroidetes. Nat Microbiol 2022; 7:986-1000. [PMID: 35725777 PMCID: PMC9246714 DOI: 10.1038/s41564-022-01152-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/17/2022] [Indexed: 12/13/2022]
Abstract
Inositol lipids are ubiquitous in eukaryotes and have finely tuned roles in cellular signalling and membrane homoeostasis. In Bacteria, however, inositol lipid production is relatively rare. Recently, the prominent human gut bacterium Bacteroides thetaiotaomicron (BT) was reported to produce inositol lipids and sphingolipids, but the pathways remain ambiguous and their prevalence unclear. Here, using genomic and biochemical approaches, we investigated the gene cluster for inositol lipid synthesis in BT using a previously undescribed strain with inducible control of sphingolipid synthesis. We characterized the biosynthetic pathway from myo-inositol-phosphate (MIP) synthesis to phosphoinositol dihydroceramide, determined the crystal structure of the recombinant BT MIP synthase enzyme and identified the phosphatase responsible for the conversion of bacterially-derived phosphatidylinositol phosphate (PIP-DAG) to phosphatidylinositol (PI-DAG). In vitro, loss of inositol lipid production altered BT capsule expression and antimicrobial peptide resistance. In vivo, loss of inositol lipids decreased bacterial fitness in a gnotobiotic mouse model. We identified a second putative, previously undescribed pathway for bacterial PI-DAG synthesis without a PIP-DAG intermediate, common in Prevotella. Our results indicate that inositol sphingolipid production is widespread in host-associated Bacteroidetes and has implications for symbiosis. The pathways responsible for inositol lipid production in human gut Bacteroides are characterized and these lipids are important for capsule expression and antimicrobial peptide resistance in vitro and colonization in vivo.
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8
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Banahene N, Kavunja HW, Swarts BM. Chemical Reporters for Bacterial Glycans: Development and Applications. Chem Rev 2022; 122:3336-3413. [PMID: 34905344 PMCID: PMC8958928 DOI: 10.1021/acs.chemrev.1c00729] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bacteria possess an extraordinary repertoire of cell envelope glycans that have critical physiological functions. Pathogenic bacteria have glycans that are essential for growth and virulence but are absent from humans, making them high-priority targets for antibiotic, vaccine, and diagnostic development. The advent of metabolic labeling with bioorthogonal chemical reporters and small-molecule fluorescent reporters has enabled the investigation and targeting of specific bacterial glycans in their native environments. These tools have opened the door to imaging glycan dynamics, assaying and inhibiting glycan biosynthesis, profiling glycoproteins and glycan-binding proteins, and targeting pathogens with diagnostic and therapeutic payload. These capabilities have been wielded in diverse commensal and pathogenic Gram-positive, Gram-negative, and mycobacterial species─including within live host organisms. Here, we review the development and applications of chemical reporters for bacterial glycans, including peptidoglycan, lipopolysaccharide, glycoproteins, teichoic acids, and capsular polysaccharides, as well as mycobacterial glycans, including trehalose glycolipids and arabinan-containing glycoconjugates. We cover in detail how bacteria-targeting chemical reporters are designed, synthesized, and evaluated, how they operate from a mechanistic standpoint, and how this information informs their judicious and innovative application. We also provide a perspective on the current state and future directions of the field, underscoring the need for interdisciplinary teams to create novel tools and extend existing tools to support fundamental and translational research on bacterial glycans.
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Affiliation(s)
- Nicholas Banahene
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, United States
- Biochemistry, Cell, and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI, United States
| | - Herbert W. Kavunja
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, MI, United States
- Biochemistry, Cell, and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI, United States
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9
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Anso I, Basso LGM, Wang L, Marina A, Páez-Pérez ED, Jäger C, Gavotto F, Tersa M, Perrone S, Contreras FX, Prandi J, Gilleron M, Linster CL, Corzana F, Lowary TL, Trastoy B, Guerin ME. Molecular ruler mechanism and interfacial catalysis of the integral membrane acyltransferase PatA. SCIENCE ADVANCES 2021; 7:eabj4565. [PMID: 34652941 PMCID: PMC8519569 DOI: 10.1126/sciadv.abj4565] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/24/2021] [Indexed: 05/28/2023]
Abstract
Glycolipids are prominent components of bacterial membranes that play critical roles not only in maintaining the structural integrity of the cell but also in modulating host-pathogen interactions. PatA is an essential acyltransferase involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs), key structural elements and virulence factors of Mycobacterium tuberculosis. We demonstrate by electron spin resonance spectroscopy and surface plasmon resonance that PatA is an integral membrane acyltransferase tightly anchored to anionic lipid bilayers, using a two-helix structural motif and electrostatic interactions. PatA dictates the acyl chain composition of the glycolipid by using an acyl chain selectivity “ruler.” We established this by a combination of structural biology, enzymatic activity, and binding measurements on chemically synthesized nonhydrolyzable acyl–coenzyme A (CoA) derivatives. We propose an interfacial catalytic mechanism that allows PatA to acylate hydrophobic PIMs anchored in the inner membrane of mycobacteria, through the use of water-soluble acyl-CoA donors.
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Affiliation(s)
- Itxaso Anso
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
- Structural Glycobiology Laboratory, Biocruces Bizkaia Health Research Institute, Cruces University Hospital, 48903 Barakaldo, Bizkaia, Spain
| | - Luis G. M. Basso
- Laboratório de Ciências Físicas, Centro de Ciência e Tecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, Campos dos Goytacazes, 28013-602 Rio de Janeiro, Brazil
- Laboratório de Biofísica Molecular, Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes, 3900, 14040-901 Ribeirão Preto, São Paulo, Brazil
| | - Lei Wang
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Alberto Marina
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
| | - Edgar D. Páez-Pérez
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica A.C., San Luis Potosí, México
| | - Christian Jäger
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux, Luxembourg
| | - Floriane Gavotto
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux, Luxembourg
| | - Montse Tersa
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
| | - Sebastián Perrone
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
- Structural Glycobiology Laboratory, Biocruces Bizkaia Health Research Institute, Cruces University Hospital, 48903 Barakaldo, Bizkaia, Spain
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux, Luxembourg
| | - F.-Xabier Contreras
- Instituto Biofisika, Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, 48940 Bizkaia, Spain
- Departamento de Bioquímica, Universidad del País Vasco, Leioa, 48940 Bizkaia, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Jacques Prandi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, F-31077 Toulouse, France
| | - Martine Gilleron
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, F-31077 Toulouse, France
| | - Carole L. Linster
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux, Luxembourg
| | - Francisco Corzana
- Departamento Química and Centro de Investigación en Síntesis Química, Universidad de La Rioja, 26006 Rioja, Spain
| | - Todd L. Lowary
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
- Institute of Biological Chemistry, Academia Sinica, Academia Road, Section 2, #128, Nangang, Taipei 11529, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Section 4, #1, Roosevelt Road, Taipei 10617, Taiwan
| | - Beatriz Trastoy
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
- Structural Glycobiology Laboratory, Biocruces Bizkaia Health Research Institute, Cruces University Hospital, 48903 Barakaldo, Bizkaia, Spain
| | - Marcelo E. Guerin
- Structural Glycobiology Laboratory, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
- Structural Glycobiology Laboratory, Biocruces Bizkaia Health Research Institute, Cruces University Hospital, 48903 Barakaldo, Bizkaia, Spain
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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10
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Sieniawska E, Sawicki R, Marchev AS, Truszkiewicz W, Georgiev MI. Tanshinones from Salvia miltiorrhiza inhibit Mycobacterium tuberculosis via disruption of the cell envelope surface and oxidative stress. Food Chem Toxicol 2021; 156:112405. [PMID: 34273428 DOI: 10.1016/j.fct.2021.112405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 11/24/2022]
Abstract
The unique structure of Mycobacterium tuberculosis cell envelope provides impermeable barrier against environmental stimuli. In the situation that this barrier is disturbed Mycobacteria react at the transcriptional and translational level to redirect metabolic processes and to maintain integrity of the cell. In this work we aimed to explore the early metabolic response of M. tuberculosis to tanshinones, which are active antimycobacterial compounds of Salvia miltiorrhiza Bunge root. The investigation of the expression of sigma factors revealed the significant shifts in the general bacterial regulatory network, whereas LC-MS metabolomics evidenced the changes in the composition of bacterial cell envelope and indicated altered metabolic pathways. Tanshinones acted via the disruption of the cell envelope surface and generation of reactive oxygen species. Bacteria responded with overproduction of inner region of outer membrane, fluctuations in the production of glycerophosphoinositolglycans, as well as changes in the levels of mycobactins, accompanied by enrichment of metabolic pathways related to redox balance and repair of damages caused by tanshinones.
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Affiliation(s)
- Elwira Sieniawska
- Medical University of Lublin, Chair and Department of Pharmacognosy, Lublin, Poland.
| | - Rafal Sawicki
- Medical University of Lublin, Chair and Department of Biochemistry and Biotechnology, Lublin, Poland.
| | - Andrey S Marchev
- Bulgarian Academy of Sciences, The Stephan Angeloff Institute of Microbiology, Laboratory of Metabolomics, Plovdiv, Bulgaria; Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria.
| | - Wieslaw Truszkiewicz
- Medical University of Lublin, Chair and Department of Biochemistry and Biotechnology, Lublin, Poland.
| | - Milen I Georgiev
- Bulgarian Academy of Sciences, The Stephan Angeloff Institute of Microbiology, Laboratory of Metabolomics, Plovdiv, Bulgaria; Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria.
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Ramp P, Lehnert A, Matamouros S, Wirtz A, Baumgart M, Bott M. Metabolic engineering of Corynebacterium glutamicum for production of scyllo-inositol, a drug candidate against Alzheimer's disease. Metab Eng 2021; 67:173-185. [PMID: 34224896 DOI: 10.1016/j.ymben.2021.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/17/2021] [Accepted: 06/30/2021] [Indexed: 10/20/2022]
Abstract
Scyllo-inositol has been identified as a potential drug for the treatment of Alzheimer's disease. Therefore, cost-efficient processes for the production of this compound are desirable. In this study, we analyzed and engineered Corynebacterium glutamicum with the aim to develop competitive scyllo-inositol producer strains. Initial studies revealed that C. glutamicum naturally produces scyllo-inositol when cultured with myo-inositol as carbon source. The conversion involves NAD+-dependent oxidation of myo-inositol to 2-keto-myo-inositol followed by NADPH-dependent reduction to scyllo-inositol. Use of myo-inositol for biomass formation was prevented by deletion of a cluster of 16 genes involved in myo-inositol catabolism (strain MB001(DE3)Δiol1). Deletion of a second cluster of four genes (oxiC-cg3390-oxiD-oxiE) related to inositol metabolism prevented conversion of 2-keto-myo-inositol to undesired products causing brown coloration (strain MB001(DE3)Δiol1Δiol2). The two chassis strains were used for plasmid-based overproduction of myo-inositol dehydrogenase (IolG) and scyllo-inositol dehydrogenase (IolW). In BHI medium containing glucose and myo-inositol, a complete conversion of the consumed myo-inositol into scyllo-inositol was achieved with the Δiol1Δiol2 strain. To enable scyllo-inositol production from cheap carbon sources, myo-inositol 1-phosphate synthase (Ino1) and myo-inositol 1-phosphatase (ImpA), which convert glucose 6-phosphate into myo-inositol, were overproduced in addition to IolG and IolW using plasmid pSI. Strain MB001(DE3)Δiol1Δiol2 (pSI) produced 1.8 g/L scyllo-inositol from 20 g/L glucose and even 4.4 g/L scyllo-inositol from 20 g/L sucrose within 72 h. Our results demonstrate that C. glutamicum is an attractive host for the biotechnological production of scyllo-inositol and potentially further myo-inositol-derived products.
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Affiliation(s)
- Paul Ramp
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
| | - Alexander Lehnert
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
| | - Susana Matamouros
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
| | - Astrid Wirtz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany.
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12
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Sieniawska E, Sawicki R, Truszkiewicz W, Marchev AS, Georgiev MI. Usnic Acid Treatment Changes the Composition of Mycobacterium tuberculosis Cell Envelope and Alters Bacterial Redox Status. mSystems 2021; 6:e00097-21. [PMID: 33947802 PMCID: PMC8269206 DOI: 10.1128/msystems.00097-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/29/2021] [Indexed: 12/29/2022] Open
Abstract
Mycobacterium tuberculosis developed efficient adaptation mechanisms in response to different environmental conditions. This resulted in the ability to survive in human macrophages and in resistance to numerous antibiotics. To get insight into bacterial responses to potent antimycobacterial natural compounds, we tested how usnic acid, a lichen-derived secondary metabolite, would influence mycobacteria at transcriptomic and metabolomic levels. The analysis of expression of sigma factors revealed a profound impact of usnic acid on one of the primary genetic regulatory systems of M. tuberculosis Combined liquid chromatography-mass spectrometry and nuclear magnetic resonance analyses allowed us to observe the perturbations in metabolic pathways, as well as in lipid composition, which took place within 24 h of exposure. Early bacterial response was related to redox homeostasis, lipid synthesis, and nucleic acid repair. Usnic acid treatment provoked disturbances of redox state in mycobacterial cells and increased production of structural elements of the cell wall and cell membrane. In addition, to increase the number of molecules related to restoration of redox balance, the rearrangements of the cell envelope were the first defense mechanisms observed under usnic acid treatment.IMPORTANCE The evaluation of mechanisms of mycobacterial response to natural products has been barely studied. However, it might be helpful to reveal bacterial adaptation strategies, which are eventually crucial for the discovery of new drug targets and, hence, understanding the resistance mechanisms. This study showed that the first-line mycobacterial defense against usnic acid, a potent antimicrobial agent, is the remodeling of the cell envelope and restoring redox homeostasis. Transcriptomic data correlated with metabolomics analysis. The observed metabolic changes appeared similar to those exerted by antibiotics.
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Affiliation(s)
- Elwira Sieniawska
- Medical University of Lublin, Chair and Department of Pharmacognosy, Lublin, Poland
| | - Rafal Sawicki
- Medical University of Lublin, Chair and Department of Biochemistry and Biotechnology, Lublin, Poland
| | - Wieslaw Truszkiewicz
- Medical University of Lublin, Chair and Department of Biochemistry and Biotechnology, Lublin, Poland
| | - Andrey S Marchev
- Bulgarian Academy of Sciences, The Stephan Angeloff Institute of Microbiology, Laboratory of Metabolomics, Plovdiv, Bulgaria
- Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria
| | - Milen I Georgiev
- Bulgarian Academy of Sciences, The Stephan Angeloff Institute of Microbiology, Laboratory of Metabolomics, Plovdiv, Bulgaria
- Center of Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria
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The Phosphatidyl- myo-Inositol Dimannoside Acyltransferase PatA Is Essential for Mycobacterium tuberculosis Growth In Vitro and In Vivo. J Bacteriol 2021; 203:JB.00439-20. [PMID: 33468587 DOI: 10.1128/jb.00439-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/30/2020] [Indexed: 01/20/2023] Open
Abstract
Mycobacterium tuberculosis comprises an unusual cell envelope dominated by unique lipids and glycans that provides a permeability barrier against hydrophilic drugs and is central for its survival and virulence. Phosphatidyl-myo-inositol mannosides (PIMs) are glycolipids considered to be not only key structural components of the cell envelope but also the precursors of lipomannan (LM) and lipoarabinomannan (LAM), important lipoglycans implicated in host-pathogen interactions. Here, we focus on PatA, a membrane-associated acyltransferase that transfers a palmitoyl moiety from palmitoyl coenzyme A (palmitoyl-CoA) to the 6-position of the mannose ring linked to the 2-position of inositol in PIM1/PIM2 We validate that the function of PatA is vital for M. tuberculosis in vitro and in vivo We constructed a patA conditional mutant and showed that silencing patA is bactericidal in batch cultures. This phenotype was associated with significantly reduced levels of Ac1PIM2, an important structural component of the mycobacterial inner membrane. The requirement of PatA for viability was also demonstrated during macrophage infection and in a mouse model of infection, where a dramatic decrease in viable counts was observed upon silencing of the patA gene. This is reminiscent of the behavior of PimA, the mannosyltransferase that initiates the PIM pathway, also found to be essential for M. tuberculosis growth in vitro and in vivo Altogether, the experimental data highlight the significance of the early steps of the PIM biosynthetic pathway for M. tuberculosis physiology and reveal that PatA is a novel target for drug discovery programs against this major human pathogen.IMPORTANCE Tuberculosis (TB) is the leading cause of death from a single infectious agent. The emergence of drug resistance in strains of M. tuberculosis, the etiologic agent of TB, emphasizes the need to identify new targets and antimicrobial agents. The mycobacterial cell envelope is a major factor in this intrinsic drug resistance. Here, we have focused on the biosynthesis of PIMs, key virulence factors and important components of the cell envelope. Specifically, we have determined that PatA, the acyltransferase responsible for the first acylation step of the PIM synthesis pathway, is essential in M. tuberculosis These results highlight the importance of early steps of the PIM biosynthetic pathway for mycobacterial physiology and the suitability of PatA as a potential new drug target.
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Comparative genomics and metabolomics analysis of Riemerella anatipestifer strain CH-1 and CH-2. Sci Rep 2021; 11:616. [PMID: 33436670 PMCID: PMC7804117 DOI: 10.1038/s41598-020-79733-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 12/04/2020] [Indexed: 12/28/2022] Open
Abstract
Riemerella anatipestifer is a major pathogenic microorganism in poultry causing serositis with significant mortality. Serotype 1 and 2 were most pathogenic, prevalent, and liable over the world. In this study, the intracellular metabolites in R. anatipestifer strains RA-CH-1 (serotype 1) and RA-CH-2 (serotype 2) were identified by gas chromatography-mass spectrometer (GC–MS). The metabolic profiles were performed using hierarchical clustering and partial least squares discriminant analysis (PLS-DA). The results of hierarchical cluster analysis showed that the amounts of the detected metabolites were more abundant in RA-CH-2. RA-CH-1 and RA-CH-2 were separated by the PLS-DA model. 24 potential biomarkers participated in nine metabolisms were contributed predominantly to the separation. Based on the complete genome sequence database and metabolite data, the first large-scale metabolic models of iJL463 (RA-CH-1) and iDZ470 (RA-CH-2) were reconstructed. In addition, we explained the change of purine metabolism combined with the transcriptome and metabolomics data. The study showed that it is possible to detect and differentiate between these two organisms based on their intracellular metabolites using GC–MS. The present research fills a gap in the metabolomics characteristics of R. anatipestifer.
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15
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Ausmus AP, Hogue M, Snyder JL, Rundell SR, Bednarz KM, Banahene N, Swarts BM. Ferrier Carbocyclization-Mediated Synthesis of Enantiopure Azido Inositol Analogues. J Org Chem 2020; 85:3182-3191. [DOI: 10.1021/acs.joc.9b03064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alex P. Ausmus
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Maxwell Hogue
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Justin L. Snyder
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Sarah R. Rundell
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Krestina M. Bednarz
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Nicholas Banahene
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Benjamin M. Swarts
- Department of Chemistry and Biochemistry, Central Michigan University, Mount Pleasant, Michigan 48859, United States
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16
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Koets AP, van den Esker MH, Riepema K, Bakker D. The Role of Phosphatidylinositol Mannosides in the Serological Diagnosis of Mycobacterial Infections. Vet Sci 2019; 6:E91. [PMID: 31766256 PMCID: PMC6958488 DOI: 10.3390/vetsci6040091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/04/2019] [Accepted: 11/08/2019] [Indexed: 11/16/2022] Open
Abstract
Accurate diagnosis of mycobacterial infections, such as bovine tuberculosis and paratuberculosis, remains challenging. Available direct diagnostic tests aimed at detecting the pathogen are highly specific but lack sensitivity, depending on the stage of infection and the prevalence of infection in a population. The sensitivity of indirect diagnostic assays that measure the host immune response to infection is similarly affected by disease characteristics. The choice of antigen used to detect a host response to infection has a critical impact on test sensitivity and specificity. Many indirect tests rely on crude antigen preparations and cell-free extracts, of which the production is poorly standardized. Moreover, these preparations contain ample uncharacterized cross-reactive compounds. To enhance serological test specificity, existing assays depend on the pre-treatment of samples and a relatively high cut-off value, that in turn influences test sensitivity. Research therefore focuses on the identification of more specific, defined antigens to improve diagnostics. In the current study, we extracted phosphatidylinositol mannosides (PIMs) and investigated their potential use in antibody-based tests. Our results demonstrate that specific IgG class antibodies are generated against PIMs in cows, but this is unrelated to tuberculosis or paratuberculosis infection status, making these antigens unsuitable for diagnostic applications. In addition, we demonstrate that PIMs are widely present in crude antigen preparations and in serum pre-absorption buffer. Our results indicate that PIMs are cross-reactive compounds with immunodominant B cell epitopes that could impair serological test specificity.
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Affiliation(s)
- Ad P. Koets
- Department of Bacteriology and Epidemiology, Wageningen Bioveterinary Research, Houtribweg 398221 RA Lelystad, The Netherlands; (M.H.v.d.E.); (K.R.)
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 73584 CL Utrecht, The Netherlands
| | - Marielle H. van den Esker
- Department of Bacteriology and Epidemiology, Wageningen Bioveterinary Research, Houtribweg 398221 RA Lelystad, The Netherlands; (M.H.v.d.E.); (K.R.)
| | - Karel Riepema
- Department of Bacteriology and Epidemiology, Wageningen Bioveterinary Research, Houtribweg 398221 RA Lelystad, The Netherlands; (M.H.v.d.E.); (K.R.)
| | - Douwe Bakker
- Independent Researcher, 8212 AM Lelystad, The Netherlands;
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17
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Eagen WJ, Baumoel LR, Osman SH, Rahlwes KC, Morita YS. Deletion of PimE mannosyltransferase results in increased copper sensitivity in Mycobacterium smegmatis. FEMS Microbiol Lett 2019; 365:4830098. [PMID: 29390083 DOI: 10.1093/femsle/fny025] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/26/2018] [Indexed: 12/20/2022] Open
Abstract
The unique cell envelope structure of Mycobacterium tuberculosis is fundamental to its pathogenesis. Phosphatidylinositol (PI)-anchored glycolipids, such as phosphatidylinositol mannosides (PIMs), lipomannan and lipoarabinomannan, are essential components of the cell envelope widely conserved among mycobacteria, but their roles in the cell envelope integrity are not fully understood. We previously identified PimE in Mycobacterium smegmatis, a nonpathogenic model organism, as a mannosyltransferase that catalyzes the fifth mannose transfer for the biosynthesis of hexamannosyl PIMs. Our analyses, reported here, further demonstrate that the growth of the pimE deletion mutant (ΔpimE) is defective in the presence of copper. We first found that the small colony phenotype of ΔpimE on a solid Middlebrook 7H10 agar surface was alleviated when grown on M63 agar. Comparative analysis of the two media led us to identify copper in Middlebrook 7H10 as the cause of growth retardation seen in ΔpimE. We further demonstrated that ΔpimE is sensitized to several antibiotics, but the increased sensitivities were independent of the presence of copper. We conclude that the deletion of the pimE gene does not cause growth defects under optimal growth conditions, but makes the cell envelope vulnerable to toxic compounds such as copper and antibiotics.
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Affiliation(s)
- William J Eagen
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Lisa R Baumoel
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Sarah H Osman
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
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18
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Grāve K, Bennett MD, Högbom M. Structure of Mycobacterium tuberculosis phosphatidylinositol phosphate synthase reveals mechanism of substrate binding and metal catalysis. Commun Biol 2019; 2:175. [PMID: 31098408 PMCID: PMC6506517 DOI: 10.1038/s42003-019-0427-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/16/2019] [Indexed: 12/16/2022] Open
Abstract
Tuberculosis causes over one million yearly deaths, and drug resistance is rapidly developing. Mycobacterium tuberculosis phosphatidylinositol phosphate synthase (PgsA1) is an integral membrane enzyme involved in biosynthesis of inositol-derived phospholipids required for formation of the mycobacterial cell wall, and a potential drug target. Here we present three crystal structures of M. tuberculosis PgsA1: in absence of substrates (2.9 Å), in complex with Mn2+ and citrate (1.9 Å), and with the CDP-DAG substrate (1.8 Å). The structures reveal atomic details of substrate binding as well as coordination and dynamics of the catalytic metal site. In addition, molecular docking supported by mutagenesis indicate a binding mode for the second substrate, D-myo-inositol-3-phosphate. Together, the data describe the structural basis for M. tuberculosis phosphatidylinositol phosphate synthesis and suggest a refined general catalytic mechanism-including a substrate-induced carboxylate shift-for Class I CDP-alcohol phosphotransferases, enzymes essential for phospholipid biosynthesis in all domains of life.
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Affiliation(s)
- Kristīne Grāve
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16 C, SE-106 91 Stockholm, Sweden
| | - Matthew D. Bennett
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16 C, SE-106 91 Stockholm, Sweden
| | - Martin Högbom
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrhenius väg 16 C, SE-106 91 Stockholm, Sweden
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Rahlwes KC, Puffal J, Morita YS. Purification and Analysis of Mycobacterial Phosphatidylinositol Mannosides, Lipomannan, and Lipoarabinomannan. Methods Mol Biol 2019; 1954:59-75. [PMID: 30864124 DOI: 10.1007/978-1-4939-9154-9_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Mycobacteria and related bacteria in the Actinobacteria phylum are unusual in that they produce phosphatidylinositol (PI) as a major phospholipid species. PI can be further modified by glycan polymers, leading to the synthesis of PI mannosides (PIMs), lipomannan (LM), and lipoarabinomannan (LAM). Small lipids such as PI and PIMs are extracted with a mixture of chloroform, methanol, and water and analyzed by thin layer chromatography. For larger glycolipids, such as LM and LAM, more hydrophilic solvent is needed for the extraction, and SDS-PAGE is better suited for the analysis. For LM, further structural characterization can be performed by MALDI-TOF mass spectrometry. Precise quantification of PIMs, LM, and LAM can be performed by quantification of glycan staining using analytical software. The metabolic radiolabeling protocol is also described.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Julia Puffal
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA.
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20
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Abstract
Actinobacteria is a group of diverse bacteria. Most species in this class of bacteria are filamentous aerobes found in soil, including the genus Streptomyces perhaps best known for their fascinating capabilities of producing antibiotics. These bacteria typically have a Gram-positive cell envelope, comprised of a plasma membrane and a thick peptidoglycan layer. However, there is a notable exception of the Corynebacteriales order, which has evolved a unique type of outer membrane likely as a consequence of convergent evolution. In this chapter, we will focus on the unique cell envelope of this order. This cell envelope features the peptidoglycan layer that is covalently modified by an additional layer of arabinogalactan . Furthermore, the arabinogalactan layer provides the platform for the covalent attachment of mycolic acids , some of the longest natural fatty acids that can contain ~100 carbon atoms per molecule. Mycolic acids are thought to be the main component of the outer membrane, which is composed of many additional lipids including trehalose dimycolate, also known as the cord factor. Importantly, a subset of bacteria in the Corynebacteriales order are pathogens of human and domestic animals, including Mycobacterium tuberculosis. The surface coat of these pathogens are the first point of contact with the host immune system, and we now know a number of host receptors specific to molecular patterns exposed on the pathogen's surface, highlighting the importance of understanding how the cell envelope of Actinobacteria is structured and constructed. This chapter describes the main structural and biosynthetic features of major components found in the actinobacterial cell envelopes and highlights the key differences between them.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA.
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21
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Henson WR, Hsu FF, Dantas G, Moon TS, Foston M. Lipid metabolism of phenol-tolerant Rhodococcus opacus strains for lignin bioconversion. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:339. [PMID: 30607174 PMCID: PMC6309088 DOI: 10.1186/s13068-018-1337-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Lignin is a recalcitrant aromatic polymer that is a potential feedstock for renewable fuel and chemical production. Rhodococcus opacus PD630 is a promising strain for the biological upgrading of lignin due to its ability to tolerate and utilize lignin-derived aromatic compounds. To enhance its aromatic tolerance, we recently applied adaptive evolution using phenol as a sole carbon source and characterized a phenol-adapted R. opacus strain (evol40) and the wild-type (WT) strain by whole genome and RNA sequencing. While this effort increased our understanding of the aromatic tolerance, the tolerance mechanisms were not completely elucidated. RESULTS We hypothesize that the composition of lipids plays an important role in phenol tolerance. To test this hypothesis, we applied high-resolution mass spectrometry analysis to lipid samples obtained from the WT and evol40 strains grown in 1 g/L glucose (glucose), 0.75 g/L phenol (low phenol), or 1.5 g/L phenol (high phenol, evol40 only) as a sole carbon source. This analysis identified > 100 lipid species of mycolic acids, phosphatidylethanolamines (PEs), phosphatidylinositols (PIs), and triacylglycerols. In both strains, mycolic acids had fewer double bond numbers in phenol conditions than the glucose condition, and evol40 had significantly shorter mycolic acid chain lengths than the WT strain in phenol conditions. These results indicate that phenol adaptation affected mycolic acid membrane composition. In addition, the percentage of unsaturated phospholipids decreased for both strains in phenol conditions compared to the glucose condition. Moreover, the PI content increased for both strains in the low phenol condition compared to the glucose condition, and the PI content increased further for evol40 in the high phenol condition relative to the low phenol condition. CONCLUSIONS This work represents the first comprehensive lipidomic study on the membrane of R. opacus grown using phenol as a sole carbon source. Our results suggest that the alteration of the mycolic acid and phospholipid membrane composition may be a strategy of R. opacus for phenol tolerance.
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Affiliation(s)
- William R. Henson
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid Research, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Gautam Dantas
- Department of Pathology and Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63108 USA
- The Edison Family Center for Genome Sciences and Systems Biology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110 USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
- Department of Molecular Microbiology, Washington University in St. Louis, St. Louis, MO 63108 USA
| | - Tae Seok Moon
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
| | - Marcus Foston
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130 USA
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22
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Raze D, Verwaerde C, Deloison G, Werkmeister E, Coupin B, Loyens M, Brodin P, Rouanet C, Locht C. Heparin-Binding Hemagglutinin Adhesin (HBHA) Is Involved in Intracytosolic Lipid Inclusions Formation in Mycobacteria. Front Microbiol 2018; 9:2258. [PMID: 30333800 PMCID: PMC6176652 DOI: 10.3389/fmicb.2018.02258] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/05/2018] [Indexed: 12/19/2022] Open
Abstract
The heparin-binding hemagglutinin adhesin (HBHA) is an important virulence factor of Mycobacterium tuberculosis. It is a surface-displayed protein that serves as an adhesin for non-phagocytic cells and is involved in extra-pulmonary dissemination of the tubercle bacillus. It is also an important latency antigen useful for the diagnosis of latently M. tuberculosis-infected individuals. Using fluorescence time-lapse microscopy on mycobacteria that produce HBHA-green fluorescent protein chimera, we show here that HBHA can be found at two different locations and dynamically alternates between the mycobacterial surface and the interior of the cell, where it participates in the formation of intracytosolic lipid inclusions (ILI). Compared to HBHA-producing mycobacteria, HBHA-deficient mutants contain significantly lower amounts of ILI when grown in vitro or within macrophages, and the sizes of their ILI are significantly smaller. Lipid-binding assays indicate that HBHA is able to specifically bind to phosphatidylinositol and in particular to 4,5 di-phosphorylated phosphatidylinositol, but not to neutral lipids, the main constituents of ILI. HBHA derivatives lacking the C-terminal methylated, lysine-rich repeat region fail to bind to these lipids and these derivatives also fail to complement the phenotype of HBHA-deficient mutants. These studies indicate that HBHA is a moonlighting protein that serves several functions depending on its location. When surface exposed, HBHA serves as an adhesin, and when intracellularly localized, it participates in the generation of ILI, possibly as a cargo to transport phospholipids from the plasma membrane to the ILI in the process of being formed.
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Affiliation(s)
- Dominique Raze
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Claudie Verwaerde
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Gaspard Deloison
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Elisabeth Werkmeister
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Baptiste Coupin
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Marc Loyens
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Priscille Brodin
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Carine Rouanet
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
| | - Camille Locht
- CNRS UMR8204, INSERM U1019, Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Université de Lille, Lille, France
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23
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Killiny N, Jones SE. Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing. PLoS One 2018; 13:e0191871. [PMID: 29370262 PMCID: PMC5785020 DOI: 10.1371/journal.pone.0191871] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 01/12/2018] [Indexed: 11/24/2022] Open
Abstract
Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS). Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.
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Affiliation(s)
- Nabil Killiny
- Citrus Research and Education Center, Department of Plant Pathology, IFAS, University of Florida, Lake Alfred, Florida, United States of America
| | - Shelley E Jones
- Citrus Research and Education Center, Department of Plant Pathology, IFAS, University of Florida, Lake Alfred, Florida, United States of America
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24
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Tersa M, Raich L, Albesa-Jové D, Trastoy B, Prandi J, Gilleron M, Rovira C, Guerin ME. The Molecular Mechanism of Substrate Recognition and Catalysis of the Membrane Acyltransferase PatA from Mycobacteria. ACS Chem Biol 2018; 13:131-140. [PMID: 29185694 DOI: 10.1021/acschembio.7b00578] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Glycolipids play a central role in a variety of important biological processes in all living organisms. PatA is a membrane acyltransferase involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs), key structural elements, and virulence factors of Mycobacterium tuberculosis. PatA catalyzes the transfer of a palmitoyl moiety from palmitoyl-CoA to the 6-position of the mannose ring linked to the 2-position of inositol in PIM1/PIM2. We report here the crystal structure of PatA in the presence of 6-O-palmitoyl-α-d-mannopyranoside, unraveling the acceptor binding mechanism. The acceptor mannose ring localizes in a cavity at the end of a surface-exposed long groove where the active site is located, whereas the palmitate moiety accommodates into a hydrophobic pocket deeply buried in the α/β core of the protein. Both fatty acyl chains of the PIM2 acceptor are essential for the reaction to take place, highlighting their critical role in the generation of a competent active site. By the use of combined structural and quantum-mechanics/molecular-mechanics (QM/MM) metadynamics, we unravel the catalytic mechanism of PatA at the atomic-electronic level. Our study provides a detailed structural rationale for a stepwise reaction, with the generation of a tetrahedral transition state for the rate-determining step. Finally, the crystal structure of PatA in the presence of β-d-mannopyranose and palmitate suggests an inhibitory mechanism for the enzyme, providing exciting possibilities for inhibitor design and the discovery of chemotherapeutic agents against this major human pathogen.
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Affiliation(s)
- Montse Tersa
- Structural Biology
Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Lluís Raich
- Departament
de Química Inorgànica i Orgànica (Secció
de Química Orgànica) and IQTCUB, Universitat de Barcelona, 08028 Barcelona, Spain
| | - David Albesa-Jové
- Structural Biology
Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
- Departamento de
Bioquímica, Universidad del País Vasco, Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
| | - Beatriz Trastoy
- Structural Biology
Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Jacques Prandi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, F-31077 Toulouse, France
| | - Martine Gilleron
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, F-31077 Toulouse, France
| | - Carme Rovira
- Departament
de Química Inorgànica i Orgànica (Secció
de Química Orgànica) and IQTCUB, Universitat de Barcelona, 08028 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08020 Barcelona, Spain
| | - Marcelo E. Guerin
- Structural Biology
Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
- Departamento de
Bioquímica, Universidad del País Vasco, Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain
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25
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Montersino S, Te Poele E, Orru R, Westphal AH, Barendregt A, Heck AJR, van der Geize R, Dijkhuizen L, Mattevi A, van Berkel WJH. 3-Hydroxybenzoate 6-Hydroxylase from Rhodococcus jostii RHA1 Contains a Phosphatidylinositol Cofactor. Front Microbiol 2017; 8:1110. [PMID: 28670303 PMCID: PMC5472690 DOI: 10.3389/fmicb.2017.01110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 05/31/2017] [Indexed: 01/05/2023] Open
Abstract
3-Hydroxybenzoate 6-hydroxylase (3HB6H, EC 1.13.14.26) is a FAD-dependent monooxygenase involved in the catabolism of aromatic compounds in soil microorganisms. 3HB6H is unique among flavoprotein hydroxylases in that it harbors a phospholipid ligand. The purified protein obtained from expressing the gene encoding 3HB6H from Rhodococcus jostii RHA1 in the host Escherichia coli contains a mixture of phosphatidylglycerol and phosphatidylethanolamine, which are the major constituents of E. coli's cytoplasmic membrane. Here, we purified 3HB6H (RjHB6H) produced in the host R. jostii RHA#2 by employing a newly developed actinomycete expression system. Biochemical and biophysical analysis revealed that Rj3HB6H possesses similar catalytic and structural features as 3HB6H, but now contains phosphatidylinositol, which is a specific constituent of actinomycete membranes. Native mass spectrometry suggests that the lipid cofactor stabilizes monomer-monomer contact. Lipid analysis of 3HB6H from Pseudomonas alcaligenes NCIMB 9867 (Pa3HB6H) produced in E. coli supports the conclusion that 3HB6H enzymes have an intrinsic ability to bind phospholipids with different specificity, reflecting the membrane composition of their bacterial host.
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Affiliation(s)
- Stefania Montersino
- Laboratory of Biochemistry, Wageningen University and ResearchWageningen, Netherlands
| | - Evelien Te Poele
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Roberto Orru
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University and ResearchWageningen, Netherlands
| | - Arjan Barendregt
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Research, Utrecht UniversityUtrecht, Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Research, Utrecht UniversityUtrecht, Netherlands
| | - Robert van der Geize
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Andrea Mattevi
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University and ResearchWageningen, Netherlands
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26
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Structural basis of phosphatidyl-myo-inositol mannosides biosynthesis in mycobacteria. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:1355-1367. [PMID: 27826050 DOI: 10.1016/j.bbalip.2016.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/29/2016] [Accepted: 11/02/2016] [Indexed: 11/22/2022]
Abstract
Phosphatidyl-myo-inositol mannosides (PIMs) are glycolipids of unique chemical structure found in the inner and outer membranes of the cell envelope of all Mycobacterium species. The PIM family of glycolipids comprises phosphatidyl-myo-inositol mono-, di-, tri-, tetra-, penta-, and hexamannosides with different degrees of acylation. PIMs are considered not only essential structural components of the cell envelope but also the precursors of lipomannan and lipoarabinomannan, two major lipoglycans implicated in host-pathogen interactions. Since the description of the complete chemical structure of PIMs, major efforts have been committed to defining the molecular bases of its biosynthetic pathway. The structural characterization of the integral membrane phosphatidyl-myo-inositol phosphate synthase (PIPS), and that of three enzymes working at the protein-membrane interface, the phosphatidyl-myo-inositol mannosyltransferases A and B, and the acyltransferase PatA, established the basis of the early steps of the PIM pathway at the molecular level. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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27
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Fozo EM, Rucks EA. The Making and Taking of Lipids: The Role of Bacterial Lipid Synthesis and the Harnessing of Host Lipids in Bacterial Pathogenesis. Adv Microb Physiol 2016; 69:51-155. [PMID: 27720012 DOI: 10.1016/bs.ampbs.2016.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In order to survive environmental stressors, including those induced by growth in the human host, bacterial pathogens will adjust their membrane physiology accordingly. These physiological changes also include the use of host-derived lipids to alter their own membranes and feed central metabolic pathways. Within the host, the pathogen is exposed to many stressful stimuli. A resulting adaptation is for pathogens to scavenge the host environment for readily available lipid sources. The pathogen takes advantage of these host-derived lipids to increase or decrease the rigidity of their own membranes, to provide themselves with valuable precursors to feed central metabolic pathways, or to impact host signalling and processes. Within, we review the diverse mechanisms that both extracellular and intracellular pathogens employ to alter their own membranes as well as their use of host-derived lipids in membrane synthesis and modification, in order to increase survival and perpetuate disease within the human host. Furthermore, we discuss how pathogen employed mechanistic utilization of host-derived lipids allows for their persistence, survival and potentiation of disease. A more thorough understanding of all of these mechanisms will have direct consequences for the development of new therapeutics, and specifically, therapeutics that target pathogens, while preserving normal flora.
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Affiliation(s)
- E M Fozo
- University of Tennessee, Knoxville, TN, United States.
| | - E A Rucks
- Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States.
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28
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Rodrigo-Unzueta A, Martínez MA, Comino N, Alzari PM, Chenal A, Guerin ME. Molecular Basis of Membrane Association by the Phosphatidylinositol Mannosyltransferase PimA Enzyme from Mycobacteria. J Biol Chem 2016; 291:13955-13963. [PMID: 27189944 DOI: 10.1074/jbc.m116.723676] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Indexed: 01/09/2023] Open
Abstract
Phosphatidyl-myo-inositol mannosyltransferase A (PimA) is an essential glycosyltransferase that initiates the biosynthetic pathway of phosphatidyl-myo-inositol mannoside, lipomannan, and lipoarabinomannan, which are key glycolipids/lipoglycans of the mycobacterial cell envelope. PimA belongs to a large family of membrane-associated glycosyltransferases for which the understanding of the molecular mechanism and conformational changes that govern substrate/membrane recognition and catalysis remains a major challenge. Here, we determined that PimA preferentially binds to negatively charged phosphatidyl-myo-inositol substrate and non-substrate membrane model systems (small unilamellar vesicle) through its N-terminal domain, inducing an important structural reorganization of anionic phospholipids. By using a combination of single-point mutagenesis, circular dichroism, and a variety of fluorescence spectroscopy techniques, we determined that this interaction is mainly mediated by an amphipathic α-helix (α2), which undergoes a substantial conformational change and localizes in the vicinity of the negatively charged lipid headgroups and the very first carbon atoms of the acyl chains, at the PimA-phospholipid interface. Interestingly, a flexible region within the N-terminal domain, which undergoes β-strand-to-α-helix and α-helix-to-β-strand transitions during catalysis, interacts with anionic phospholipids; however, the effect is markedly less pronounced to that observed for the amphipathic α2, likely reflecting structural plasticity/variability. Altogether, we propose a model in which conformational transitions observed in PimA might reflect a molten globule state that confers to PimA, a higher affinity toward the dynamic and highly fluctuating lipid bilayer.
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Affiliation(s)
- Ane Rodrigo-Unzueta
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain,; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Vizcaya, Spain
| | - Mariano A Martínez
- Institut Pasteur, Unité de Microbiologie Structurale, CNRS UMR 3528 and University Paris Diderot, Sorbonne Paris Cité, 25 Rue du Dr. Roux, 75724 Paris Cedex 15, France
| | - Natalia Comino
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain,; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Vizcaya, Spain,; Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC-bioGUNE), Bizkaia Technology Park, 48160 Derio, Spain
| | - Pedro M Alzari
- Institut Pasteur, Unité de Microbiologie Structurale, CNRS UMR 3528 and University Paris Diderot, Sorbonne Paris Cité, 25 Rue du Dr. Roux, 75724 Paris Cedex 15, France
| | - Alexandre Chenal
- Unité de Biochimie des Interactions Macromoléculaires and CNRS UMR 3528, 28 Rue du Dr. Roux, 75724, Paris Cedex 15, France.
| | - Marcelo E Guerin
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain,; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Vizcaya, Spain,; Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC-bioGUNE), Bizkaia Technology Park, 48160 Derio, Spain,; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.
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29
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Spatially distinct and metabolically active membrane domain in mycobacteria. Proc Natl Acad Sci U S A 2016; 113:5400-5. [PMID: 27114527 DOI: 10.1073/pnas.1525165113] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protected from host immune attack and antibiotic penetration by their unique cell envelope, mycobacterial pathogens cause devastating human diseases such as tuberculosis. Seamless coordination of cell growth with cell envelope elongation at the pole maintains this barrier. Unraveling this spatiotemporal regulation is a potential strategy for controlling mycobacterial infections. Our biochemical analysis previously revealed two functionally distinct membrane fractions in Mycobacterium smegmatis cell lysates: plasma membrane tightly associated with the cell wall (PM-CW) and a distinct fraction of pure membrane free of cell wall components (PMf). To provide further insight into the functions of these membrane fractions, we took the approach of comparative proteomics and identified more than 300 proteins specifically associated with the PMf, including essential enzymes involved in cell envelope synthesis such as a mannosyltransferase, Ppm1, and a galactosyltransferase, GlfT2. Furthermore, comparative lipidomics revealed the distinct lipid composition of the PMf, with specific association of key cell envelope biosynthetic precursors. Live-imaging fluorescence microscopy visualized the PMf as patches of membrane spatially distinct from the PM-CW and notably enriched in the pole of the growing cells. Taken together, our study provides the basis for assigning the PMf as a spatiotemporally distinct and metabolically active membrane domain involved in cell envelope biogenesis.
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30
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Huang X, Hernick M. Recombinant expression of a functional myo-inositol-1-phosphate synthase (MIPS) in Mycobacterium smegmatis. Protein J 2016; 34:380-90. [PMID: 26420670 DOI: 10.1007/s10930-015-9632-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Myo-inositol-1-phosphate synthase (MIPS, E.C. 5.5.1.4) catalyzes the first step in inositol production-the conversion of glucose-6-phosphate (Glc-6P) to myo-inositol-1-phosphate. While the three dimensional structure of MIPS from Mycobacterium tuberculosis has been solved, biochemical studies examining the in vitro activity have not been reported to date. Herein we report the in vitro activity of mycobacterial MIPS expressed in E. coli and Mycobacterium smegmatis. Recombinant expression in E. coli yields a soluble protein capable of binding the NAD(+) cofactor; however, it has no significant activity with the Glc-6P substrate. In contrast, recombinant expression in M. smegmatis mc(2)4517 yields a functionally active protein. Examination of structural data suggests that MtMIPS expressed in E. coli adopts a fold that is missing a key helix containing two critical (conserved) Lys side chains, which likely explains the inability of the E. coli expressed protein to bind and turnover the Glc-6P substrate. Recombinant expression in M. smegmatis may yield a protein that adopts a fold in which this key helix is formed enabling proper positioning of important side chains, thereby allowing for Glc-6P substrate binding and turnover. Detailed mechanistic studies may be feasible following optimization of the recombinant MIPS expression protocol in M. smegmatis.
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Affiliation(s)
- Xinyi Huang
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Marcy Hernick
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, 24061, USA. .,Department of Pharmaceutical Sciences, Appalachian College of Pharmacy, Oakwood, VA, 24631, USA.
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31
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Structural basis for selective recognition of acyl chains by the membrane-associated acyltransferase PatA. Nat Commun 2016; 7:10906. [PMID: 26965057 PMCID: PMC4792965 DOI: 10.1038/ncomms10906] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/30/2016] [Indexed: 11/18/2022] Open
Abstract
The biosynthesis of phospholipids and glycolipids are critical pathways for virtually all cell membranes. PatA is an essential membrane associated acyltransferase involved in the biosynthesis of mycobacterial phosphatidyl-myo-inositol mannosides (PIMs). The enzyme transfers a palmitoyl moiety from palmitoyl–CoA to the 6-position of the mannose ring linked to 2-position of inositol in PIM1/PIM2. We report here the crystal structures of PatA from Mycobacterium smegmatis in the presence of its naturally occurring acyl donor palmitate and a nonhydrolyzable palmitoyl–CoA analog. The structures reveal an α/β architecture, with the acyl chain deeply buried into a hydrophobic pocket that runs perpendicular to a long groove where the active site is located. Enzyme catalysis is mediated by an unprecedented charge relay system, which markedly diverges from the canonical HX4D motif. Our studies establish the mechanistic basis of substrate/membrane recognition and catalysis for an important family of acyltransferases, providing exciting possibilities for inhibitor design. PatA is a membrane-associated acyltransferase that is essential for the biosynthesis of mycobacterial glycolipids. Here, Albesa-Jové et al. describe structures of PatA from Mycobacterium smegmatis in complex with acyl donors and show that catalysis occurs by an unusual charge-relay mechanism.
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32
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Yassin AF, Lapidus A, Han J, Reddy TBK, Huntemann M, Pati A, Ivanova N, Markowitz V, Woyke T, Klenk HP, Kyrpides NC. High quality draft genome sequence of Corynebacterium ulceribovis type strain IMMIB-L1395(T) (DSM 45146(T)). Stand Genomic Sci 2015; 10:50. [PMID: 26380638 PMCID: PMC4572677 DOI: 10.1186/s40793-015-0036-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 07/07/2015] [Indexed: 01/21/2023] Open
Abstract
Corynebacterium ulceribovis strain IMMIB L-1395(T) (= DSM 45146(T)) is an aerobic to facultative anaerobic, Gram-positive, non-spore-forming, non-motile rod-shaped bacterium that was isolated from the skin of the udder of a cow, in Schleswig Holstein, Germany. The cell wall of C. ulceribovis contains corynemycolic acids. The cellular fatty acids are those described for the genus Corynebacterium, but tuberculostearic acid is not present. Here we describe the features of C. ulceribovis strain IMMIB L-1395(T), together with genome sequence information and its annotation. The 2,300,451 bp long genome containing 2,104 protein-coding genes and 54 RNA-encoding genes and is part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project.
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Affiliation(s)
- Atteyet F Yassin
- Institut für Medizinische Mikrobiologie und Immunologie der Universität Bonn, Bonn, Germany
| | - Alla Lapidus
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia ; Algorithmic Biology Lab, St. Petersburg Academic University, St. Petersburg, Russia
| | - James Han
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA
| | - T B K Reddy
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA
| | - Marcel Huntemann
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA
| | - Amrita Pati
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA
| | - Natalia Ivanova
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA
| | - Victor Markowitz
- Biological Data Management and Technology Center, Lawrence Berkeley National Laboratory, Berkeley, California USA
| | - Tanja Woyke
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA
| | - Hans-Peter Klenk
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Nikos C Kyrpides
- Department of Energy Joint Genome Institute, Genome Biology Program, Walnut Creek, CA USA ; Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
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33
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Megson ZA, Pittenauer E, Duda KA, Engel R, Ortmayr K, Koellensperger G, Mach L, Allmaier G, Holst O, Messner P, Schäffer C. Inositol-phosphodihydroceramides in the periodontal pathogen Tannerella forsythia: Structural analysis and incorporation of exogenous myo-inositol. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1417-27. [PMID: 26277409 PMCID: PMC4587543 DOI: 10.1016/j.bbalip.2015.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 07/28/2015] [Accepted: 08/10/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Unique phosphodihydroceramides containing phosphoethanolamine and glycerol have been previously described in Porphyromonas gingivalis. Importantly, they were shown to possess pro-inflammatory properties. Other common human bacteria were screened for the presence of these lipids, and they were found, amongst others, in the oral pathogen Tannerella forsythia. To date, no detailed study into the lipids of this organism has been performed. METHODS Lipids were extracted, separated and purified by HPTLC, and analyzed using GC-MS, ESI-MS and NMR. Of special interest was how T. forsythia acquires the metabolic precursors for the lipids studied here. This was assayed by radioactive and stable isotope incorporation using carbon-14 and deuterium labeled myo-inositol, added to the growth medium. RESULTS T. forsythia synthesizes two phosphodihydroceramides (Tf GL1, Tf GL2) which are constituted by phospho-myo-inositol linked to either a 17-, 18-, or 19-carbon sphinganine, N-linked to either a branched 17:0(3-OH) or a linear 16:0(3-OH) fatty acid which, in Tf GL2, is, in turn, ester-substituted with a branched 15:0 fatty acid. T. forsythia lacks the enzymatic machinery required for myo-inositol synthesis but was found to internalize inositol from the medium for the synthesis of both Tf GL1 and Tf GL2. CONCLUSION The study describes two novel glycolipids in T. forsythia which could be essential in this organism. Their synthesis could be reliant on an external source of myo-inositol. GENERAL SIGNIFICANCE The effects of these unique lipids on the immune system and their role in bacterial virulence could be relevant in the search for new drug targets.
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Affiliation(s)
- Zoë Anne Megson
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria
| | - Ernst Pittenauer
- Institute of Chemical Technologies and Analytics, Vienna, University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Katarzyna Anna Duda
- Department of Structural Biochemistry, Priority Area Asthma & Allergy, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 4a/4c, 23845 Borstel, Germany
| | - Regina Engel
- Department of Structural Biochemistry, Priority Area Asthma & Allergy, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 4a/4c, 23845 Borstel, Germany
| | - Karin Ortmayr
- Department of Chemistry, Universität für Bodenkultur Wien, Muthgasse 18, 1190 Vienna, Austria; Institute of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria
| | - Gunda Koellensperger
- Institute of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria
| | - Lukas Mach
- Department of Applied Genetics and Cell Biology, Universität für Bodenkultur Wien, Muthgasse 18, 1190 Vienna, Austria
| | - Günter Allmaier
- Institute of Chemical Technologies and Analytics, Vienna, University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Otto Holst
- Department of Structural Biochemistry, Priority Area Asthma & Allergy, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 4a/4c, 23845 Borstel, Germany
| | - Paul Messner
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria
| | - Christina Schäffer
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.
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Angala SK, Belardinelli JM, Huc-Claustre E, Wheat WH, Jackson M. The cell envelope glycoconjugates of Mycobacterium tuberculosis. Crit Rev Biochem Mol Biol 2014; 49:361-99. [PMID: 24915502 PMCID: PMC4436706 DOI: 10.3109/10409238.2014.925420] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of the most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last 10 years in the discovery and development of novel inhibitors targeting their biogenesis.
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Affiliation(s)
- Shiva Kumar Angala
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University , Fort Collins, CO , USA
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van Leeuwen LM, van der Kuip M, Youssef SA, de Bruin A, Bitter W, van Furth AM, van der Sar AM. Modeling tuberculous meningitis in zebrafish using Mycobacterium marinum. Dis Model Mech 2014; 7:1111-22. [PMID: 24997190 PMCID: PMC4142731 DOI: 10.1242/dmm.015453] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Tuberculous meningitis (TBM) is one of the most severe extrapulmonary manifestations of tuberculosis, with a high morbidity and mortality. Characteristic pathological features of TBM are Rich foci, i.e. brain- and spinal-cord-specific granulomas formed after hematogenous spread of pulmonary tuberculosis. Little is known about the early pathogenesis of TBM and the role of Rich foci. We have adapted the zebrafish model of Mycobacterium marinum infection (zebrafish-M. marinum model) to study TBM. First, we analyzed whether TBM occurs in adult zebrafish and showed that intraperitoneal infection resulted in granuloma formation in the meninges in 20% of the cases, with occasional brain parenchyma involvement. In zebrafish embryos, bacterial infiltration and clustering of infected phagocytes was observed after infection at three different inoculation sites: parenchyma, hindbrain ventricle and caudal vein. Infection via the bloodstream resulted in the formation of early granulomas in brain tissue in 70% of the cases. In these zebrafish embryos, infiltrates were located in the proximity of blood vessels. Interestingly, no differences were observed when embryos were infected before or after early formation of the blood-brain barrier (BBB), indicating that bacteria are able to cross this barrier with relatively high efficiency. In agreement with this observation, infected zebrafish larvae also showed infiltration of the brain tissue. Upon infection of embryos with an M. marinum ESX-1 mutant, only small clusters and scattered isolated phagocytes with high bacterial loads were present in the brain tissue. In conclusion, our adapted zebrafish-M. marinum infection model for studying granuloma formation in the brain will allow for the detailed analysis of both bacterial and host factors involved in TBM. It will help solve longstanding questions on the role of Rich foci and potentially contribute to the development of better diagnostic tools and therapeutics.
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Affiliation(s)
- Lisanne M van Leeuwen
- Department of Pediatric Infectious Diseases and Immunology, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands
| | - Martijn van der Kuip
- Department of Pediatric Infectious Diseases and Immunology, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Sameh A Youssef
- Department of Pathobiology, Utrecht University, Faculty of Veterinary Medicine, Yalelaan 1, 3508 TB, Utrecht, The Netherlands
| | - Alain de Bruin
- Department of Pathobiology, Utrecht University, Faculty of Veterinary Medicine, Yalelaan 1, 3508 TB, Utrecht, The Netherlands
| | - Wilbert Bitter
- Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands
| | - A Marceline van Furth
- Department of Pediatric Infectious Diseases and Immunology, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
| | - Astrid M van der Sar
- Department of Medical Microbiology and Infection Control, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands
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The phosphatidyl-myo-inositol mannosyltransferase PimA is essential for Mycobacterium tuberculosis growth in vitro and in vivo. J Bacteriol 2014; 196:3441-51. [PMID: 25049093 DOI: 10.1128/jb.01346-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The cell envelope of Mycobacterium tuberculosis contains glycans and lipids of peculiar structure that play prominent roles in the biology and pathogenesis of tuberculosis. Consequently, the chemical structure and biosynthesis of the cell wall have been intensively investigated in order to identify novel drug targets. Here, we validate that the function of phosphatidyl-myo-inositol mannosyltransferase PimA is vital for M. tuberculosis in vitro and in vivo. PimA initiates the biosynthesis of phosphatidyl-myo-inositol mannosides by transferring a mannosyl residue from GDP-Man to phosphatidyl-myo-inositol on the cytoplasmic side of the plasma membrane. To prove the essential nature of pimA in M. tuberculosis, we constructed a pimA conditional mutant by using the TetR-Pip off system and showed that downregulation of PimA expression causes bactericidality in batch cultures. Consistent with the biochemical reaction catalyzed by PimA, this phenotype was associated with markedly reduced levels of phosphatidyl-myo-inositol dimannosides, essential structural components of the mycobacterial cell envelope. In addition, the requirement of PimA for viability was clearly demonstrated during macrophage infection and in two different mouse models of infection, where a dramatic decrease in viable counts was observed upon silencing of the gene. Notably, depletion of PimA resulted in complete clearance of the mouse lungs during both the acute and chronic phases of infection. Altogether, the experimental data highlight the importance of the phosphatidyl-myo-inositol mannoside biosynthetic pathway for M. tuberculosis and confirm that PimA is a novel target for future drug discovery programs.
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Abstract
ABSTRACT
During infection,
Mycobacterium tuberculosis
is exposed to a diverse array of microenvironments in the human host, each with its own unique set of redox conditions. Imbalances in the redox environment of the bacillus or the host environment serve as stimuli, which could regulate virulence. The ability of
M. tuberculosis
to evade the host immune response and cause disease is largely owing to the capacity of the mycobacterium to sense changes in its environment, such as host-generated gases, carbon sources, and pathological conditions, and alter its metabolism and redox balance accordingly for survival. In this article we discuss the redox sensors that are, to date, known to be present in
M. tuberculosis
, such as the Dos dormancy regulon, WhiB family, anti-σ factors, and MosR, in addition to the strategies present in the bacillus to neutralize free radicals, such as superoxide dismutases, catalase-peroxidase, thioredoxins, and methionine sulfoxide reductases, among others.
M. tuberculosis
is peculiar in that it appears to have a hierarchy of redox buffers, namely, mycothiol and ergothioneine. We discuss the current knowledge of their biosynthesis, function, and regulation. Ergothioneine is still an enigma, although it appears to have distinct and overlapping functions with mycothiol, which enable it to protect against a wide range of toxic metabolites and free radicals generated by the host. Developing approaches to quantify the intracellular redox status of the mycobacterium will enable us to determine how the redox balance is altered in response to signals and environments that mimic those encountered in the host.
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Hernick M. Mycothiol: a target for potentiation of rifampin and other antibiotics againstMycobacterium tuberculosis. Expert Rev Anti Infect Ther 2014; 11:49-67. [DOI: 10.1586/eri.12.152] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Baumgart M, Luder K, Grover S, Gätgens C, Besra GS, Frunzke J. IpsA, a novel LacI-type regulator, is required for inositol-derived lipid formation in Corynebacteria and Mycobacteria. BMC Biol 2013; 11:122. [PMID: 24377418 PMCID: PMC3899939 DOI: 10.1186/1741-7007-11-122] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/17/2013] [Indexed: 11/10/2022] Open
Abstract
Background The development of new drugs against tuberculosis and diphtheria is focused on disrupting the biogenesis of the cell wall, the unique architecture of which confers resistance against current therapies. The enzymatic pathways involved in the synthesis of the cell wall by these pathogens are well understood, but the underlying regulatory mechanisms are largely unknown. Results Here, we characterize IpsA, a LacI-type transcriptional regulator conserved among Mycobacteria and Corynebacteria that plays a role in the regulation of cell wall biogenesis. IpsA triggers myo-inositol formation by activating ino1, which encodes inositol phosphate synthase. An ipsA deletion mutant of Corynebacterium glutamicum cultured on glucose displayed significantly impaired growth and presented an elongated cell morphology. Further studies revealed the absence of inositol-derived lipids in the cell wall and a complete loss of mycothiol biosynthesis. The phenotype of the C. glutamicum ipsA deletion mutant was complemented to different extend by homologs from Corynebacterium diphtheriae (dip1969) and Mycobacterium tuberculosis (rv3575), indicating the conserved function of IpsA in the pathogenic species. Additional targets of IpsA with putative functions in cell wall biogenesis were identified and IpsA was shown to bind to a conserved palindromic motif within the corresponding promoter regions. Myo-inositol was identified as an effector of IpsA, causing the dissociation of the IpsA-DNA complex in vitro. Conclusions This characterization of IpsA function and of its regulon sheds light on the complex transcriptional control of cell wall biogenesis in the mycolata taxon and generates novel targets for drug development.
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Affiliation(s)
| | | | | | | | | | - Julia Frunzke
- Institut für Bio- und Geowissenschaften, IBG-1: Biotechnologie, Forschungszentrum Jülich, 52425 Jülich, Germany.
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Albesa-Jové D, Giganti D, Jackson M, Alzari PM, Guerin ME. Structure-function relationships of membrane-associated GT-B glycosyltransferases. Glycobiology 2013; 24:108-24. [PMID: 24253765 DOI: 10.1093/glycob/cwt101] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Membrane-associated GT-B glycosyltransferases (GTs) comprise a large family of enzymes that catalyze the transfer of a sugar moiety from nucleotide-sugar donors to a wide range of membrane-associated acceptor substrates, mostly in the form of lipids and proteins. As a consequence, they generate a significant and diverse amount of glycoconjugates in biological membranes, which are particularly important in cell-cell, cell-matrix and host-pathogen recognition events. Membrane-associated GT-B enzymes display two "Rossmann-fold" domains separated by a deep cleft that includes the catalytic center. They associate permanently or temporarily to the phospholipid bilayer by a combination of hydrophobic and electrostatic interactions. They have the remarkable property to access both hydrophobic and hydrophilic substrates that reside within chemically distinct environments catalyzing their enzymatic transformations in an efficient manner. Here, we discuss the considerable progress that has been made in recent years in understanding the molecular mechanism that governs substrate and membrane recognition, and the impact of the conformational transitions undergone by these GTs during the catalytic cycle.
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Affiliation(s)
- David Albesa-Jové
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
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Michell RH. Inositol lipids: from an archaeal origin to phosphatidylinositol 3,5-bisphosphate faults in human disease. FEBS J 2013; 280:6281-94. [PMID: 23902363 DOI: 10.1111/febs.12452] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/22/2013] [Accepted: 07/23/2013] [Indexed: 01/12/2023]
Abstract
The last couple of decades have seen an extraordinary transformation in our knowledge and understanding of the multifarious biological roles of inositol phospholipids. Herein, I briefly consider two topics. The first is the role that recently acquired biochemical and genomic information - especially from archaeons - has played in illuminating the possible evolutionary origins of the biological employment of inositol in lipids, and some questions that these studies raise about the 'classical' biosynthetic route to phosphatidylinositol. The second is the growing recognition of the importance in eukaryotic cells of phosphatidylinositol 3,5-bisphosphate. Phosphatidylinositol 3,5-bisphosphate only entered our phosphoinositide consciousness quite recently, but it is speedily gathering a plethora of roles in diverse cellular processes and diseases thereof. These include: control of endolysosomal vesicular trafficking and of the activity of ion channels and pumps in the endolysosomal compartment; control of constitutive and stimulated protein traffic to and from plasma membrane subdomains; control of the nutrient and stress-sensing target of rapamycin complex 1 pathway (TORC1); and regulation of key genes in some central metabolic pathways.
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Giganti D, Alegre-Cebollada J, Urresti S, Albesa-Jové D, Rodrigo-Unzueta A, Comino N, Kachala M, López-Fernández S, Svergun DI, Fernández JM, Guerin ME. Conformational plasticity of the essential membrane-associated mannosyltransferase PimA from mycobacteria. J Biol Chem 2013; 288:29797-808. [PMID: 23963451 DOI: 10.1074/jbc.m113.462705] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphatidyl-myo-inositol mannosyltransferase A (PimA) is an essential glycosyltransferase (GT) that initiates the biosynthetic pathway of phosphatidyl-myo-inositol mannosides, lipomannan, and lipoarabinomannan, which are key glycolipids/lipoglycans of the mycobacterial cell envelope. PimA belongs to a large family of peripheral membrane-associated GTs for which the understanding of the molecular mechanism and conformational changes that govern substrate/membrane recognition and catalysis remains a major challenge. Here we used single molecule force spectroscopy techniques to study the mechanical and conformational properties of PimA. In our studies, we engineered a polyprotein containing PimA flanked by four copies of the well characterized I27 protein, which provides an unambiguous mechanical fingerprint. We found that PimA exhibits weak mechanical stability albeit displaying β-sheet topology expected to unfold at much higher forces. Notably, PimA unfolds following heterogeneous multiple step mechanical unfolding pathways at low force akin to molten globule states. Interestingly, the ab initio low resolution envelopes obtained from small angle x-ray scattering of the unliganded PimA and the PimA·GDP complexed forms clearly demonstrate that not only the "open" and "closed" conformations of the GT-B enzyme are largely present in solution, but in addition, PimA experiences remarkable flexibility that undoubtedly corresponds to the N-terminal "Rossmann fold" domain, which has been proved to participate in protein-membrane interactions. Based on these results and on our previous experimental data, we propose a model wherein the conformational transitions are important for the mannosyltransferase to interact with the donor and acceptor substrates/membrane.
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Affiliation(s)
- David Giganti
- From the Unidad de Biofísica, Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea, Barrio Sarriena s/n, Leioa, Bizkaia 48940, Spain
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44
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Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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45
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Parsons JB, Rock CO. Bacterial lipids: metabolism and membrane homeostasis. Prog Lipid Res 2013; 52:249-76. [PMID: 23500459 PMCID: PMC3665635 DOI: 10.1016/j.plipres.2013.02.002] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 02/27/2013] [Accepted: 02/28/2013] [Indexed: 11/29/2022]
Abstract
Membrane lipid homeostasis is a vital facet of bacterial cell physiology. For decades, research in bacterial lipid synthesis was largely confined to the Escherichia coli model system. This basic research provided a blueprint for the biochemistry of lipid metabolism that has largely defined the individual steps in bacterial fatty acid and phospholipids synthesis. The advent of genomic sequencing has revealed a surprising amount of diversity in the genes, enzymes and genetic organization of the components responsible for bacterial lipid synthesis. Although the chemical steps in fatty acid synthesis are largely conserved in bacteria, there are surprising differences in the structure and cofactor requirements for the enzymes that perform these reactions in Gram-positive and Gram-negative bacteria. This review summarizes how the explosion of new information on the diversity of biochemical and genetic regulatory mechanisms has impacted our understanding of bacterial lipid homeostasis. The potential and problems of developing therapeutics that block pathogen phospholipid synthesis are explored and evaluated. The study of bacterial lipid metabolism continues to be a rich source for new biochemistry that underlies the variety and adaptability of bacterial life styles.
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Affiliation(s)
- Joshua B Parsons
- Department of Infectious Diseases, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
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Critical roles for lipomannan and lipoarabinomannan in cell wall integrity of mycobacteria and pathogenesis of tuberculosis. mBio 2013; 4:e00472-12. [PMID: 23422411 PMCID: PMC3573661 DOI: 10.1128/mbio.00472-12] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Lipomannan (LM) and lipoarabinomannan (LAM) are mycobacterial glycolipids containing a long mannose polymer. While they are implicated in immune modulations, the significance of LM and LAM as structural components of the mycobacterial cell wall remains unknown. We have previously reported that a branch-forming mannosyltransferase plays a critical role in controlling the sizes of LM and LAM and that deletion or overexpression of this enzyme results in gross changes in LM/LAM structures. Here, we show that such changes in LM/LAM structures have a significant impact on the cell wall integrity of mycobacteria. In Mycobacterium smegmatis, structural defects in LM and LAM resulted in loss of acid-fast staining, increased sensitivity to β-lactam antibiotics, and faster killing by THP-1 macrophages. Furthermore, equivalent Mycobacterium tuberculosis mutants became more sensitive to β-lactams, and one mutant showed attenuated virulence in mice. Our results revealed previously unknown structural roles for LM and LAM and further demonstrated that they are important for the pathogenesis of tuberculosis. Tuberculosis (TB) is a global burden, affecting millions of people worldwide. Mycobacterium tuberculosis is a causative agent of TB, and understanding the biology of M. tuberculosis is essential for tackling this devastating disease. The cell wall of M. tuberculosis is highly impermeable and plays a protective role in establishing infection. Among the cell wall components, LM and LAM are major glycolipids found in all Mycobacterium species, show various immunomodulatory activities, and have been thought to play roles in TB pathogenesis. However, the roles of LM and LAM as integral parts of the cell wall structure have not been elucidated. Here we show that LM and LAM play critical roles in the integrity of mycobacterial cell wall and the pathogenesis of TB. These findings will now allow us to seek the possibility that the LM/LAM biosynthetic pathway is a chemotherapeutic target.
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Morii H, Okauchi T, Nomiya H, Ogawa M, Fukuda K, Taniguchi H. Studies of inositol 1-phosphate analogues as inhibitors of the phosphatidylinositol phosphate synthase in mycobacteria. J Biochem 2012; 153:257-66. [PMID: 23225597 DOI: 10.1093/jb/mvs141] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We previously reported a novel pathway for the biosynthesis of phosphatidylinositol in mycobacteria via phosphatidylinositol phosphate (PIP) [Morii H., Ogawa, M., Fukuda, K., Taniguchi, H., and Koga, Y (2010) J. Biochem. 148, 593-602]. PIP synthase in the pathway is a promising target for the development of new anti-mycobacterium drugs. In the present study, we evaluated the characteristics of the PIP synthase of Mycobacterium tuberculosis. Four types of compounds were chemically synthesized based on the assumption that structural homologues of inositol 1-phosphate, a PIP synthase substrate, would act as PIP synthase inhibitors, and the results confirmed that all synthesized compounds inhibited PIP synthase activity. The phosphonate analogue of inositol 1-phosphate (Ino-C-P) had the greatest inhibitory effect among the synthesized compounds examined. Kinetic analysis indicated that Ino-C-P acted as a competitive inhibitor of inositol 1-phosphate. The IC(50) value for Ino-C-P inhibition of the PIP synthase activity was estimated to be 2.0 mM. Interestingly, Ino-C-P was utilized in the same manner as the normal PIP synthase substrate, leading to the synthesis of a phosphonate analogue of PIP (PI-C-P), which had a structure similar to that of the natural product, PIP. In addition, PI-C-P had high inhibitory activity against PIP synthase.
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Affiliation(s)
- Hiroyuki Morii
- Department of Chemistry, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, 807-8555, Japan.
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Current world literature. Lipid metabolism. Curr Opin Lipidol 2012; 23:248-254. [PMID: 22576583 DOI: 10.1097/mol.0b013e3283543033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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49
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Current world literature. Curr Opin Lipidol 2012; 23:156-63. [PMID: 22418573 DOI: 10.1097/mol.0b013e3283521229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gonzalez-Salgado A, Steinmann ME, Greganova E, Rauch M, Mäser P, Sigel E, Bütikofer P. myo-Inositol uptake is essential for bulk inositol phospholipid but not glycosylphosphatidylinositol synthesis in Trypanosoma brucei. J Biol Chem 2012; 287:13313-23. [PMID: 22351763 DOI: 10.1074/jbc.m112.344812] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
myo-Inositol is an essential precursor for the production of inositol phosphates and inositol phospholipids in all eukaryotes. Intracellular myo-inositol is generated by de novo synthesis from glucose 6-phosphate or is provided from the environment via myo-inositol symporters. We show that in Trypanosoma brucei, the causative pathogen of human African sleeping sickness and nagana in domestic animals, myo-inositol is taken up via a specific proton-coupled electrogenic symport and that this transport is essential for parasite survival in culture. Down-regulation of the myo-inositol transporter using RNA interference inhibited uptake of myo-inositol and blocked the synthesis of the myo-inositol-containing phospholipids, phosphatidylinositol and inositol phosphorylceramide; in contrast, it had no effect on glycosylphosphatidylinositol production. This together with the unexpected localization of the myo-inositol transporter in both the plasma membrane and the Golgi demonstrate that metabolism of endogenous and exogenous myo-inositol in T. brucei is strictly segregated.
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Affiliation(s)
- Amaia Gonzalez-Salgado
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland
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