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Liu D, Bhunia AK. Anchorless Bacterial Moonlighting Metabolic Enzymes Modulate the Immune System and Contribute to Pathogenesis. ACS Infect Dis 2024; 10:2551-2566. [PMID: 39066728 DOI: 10.1021/acsinfecdis.4c00323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Moonlighting proteins (MPs), characterized by their ability to perform multiple physiologically unrelated functions without alterations to their primary structures, represent a fascinating class of biomolecules with significant implications for host-pathogen interactions. This Review highlights the emerging importance of metabolic moonlighting proteins (MetMPs) in bacterial pathogenesis, focusing on their non-canonical secretion and unconventional surface anchoring mechanisms. Despite lacking typical signal peptides and anchoring motifs, MetMPs such as acetaldehyde alcohol dehydrogenase (AdhE) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are secreted and localized to the bacterial surface under stress conditions, facilitating host colonization and immune evasion. The secretion of MetMPs, often observed during conditions such as resource scarcity or infection, suggests a complex regulation akin to the overexpression of heat shock proteins in response to environmental stresses. This Review proposes two potential pathways for MetMP secretion: membrane damage-induced permeability and co-transportation with traditionally secreted proteins, highlighting a remarkable bacterial adaptability. Biophysically, surface anchoring of MetMPs is driven by electrostatic interactions, bypassing the need for conventional anchoring sequences. This mechanism is exemplified by the interaction between the bifunctional enzyme AdhE (known as Listeria adhesion protein, LAP) and the internalin B (InlB) in Listeria monocytogenes, which is mediated by charged residues facilitating adhesion to host tissues. Furthermore, MetMPs play critical roles in iron homeostasis, immune modulation, and evasion, underscoring their multifaceted roles in bacterial pathogenicity. The intricate dynamics of MetMP secretion and anchoring underline the need for further research to unravel the molecular mechanisms underpinning these processes, offering potential new targets for therapeutic intervention against bacterial infections.
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Affiliation(s)
- Dongqi Liu
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana 47907, United States
| | - Arun K Bhunia
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana 47907, United States
- Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana 47907, United States
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2
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Veerapandian R, Gadad SS, Jagannath C, Dhandayuthapani S. Live Attenuated Vaccines against Tuberculosis: Targeting the Disruption of Genes Encoding the Secretory Proteins of Mycobacteria. Vaccines (Basel) 2024; 12:530. [PMID: 38793781 PMCID: PMC11126151 DOI: 10.3390/vaccines12050530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Tuberculosis (TB), a chronic infectious disease affecting humans, causes over 1.3 million deaths per year throughout the world. The current preventive vaccine BCG provides protection against childhood TB, but it fails to protect against pulmonary TB. Multiple candidates have been evaluated to either replace or boost the efficacy of the BCG vaccine, including subunit protein, DNA, virus vector-based vaccines, etc., most of which provide only short-term immunity. Several live attenuated vaccines derived from Mycobacterium tuberculosis (Mtb) and BCG have also been developed to induce long-term immunity. Since Mtb mediates its virulence through multiple secreted proteins, these proteins have been targeted to produce attenuated but immunogenic vaccines. In this review, we discuss the characteristics and prospects of live attenuated vaccines generated by targeting the disruption of the genes encoding secretory mycobacterial proteins.
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Affiliation(s)
- Raja Veerapandian
- Center of Emphasis in Infectious Diseases, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USA
| | - Shrikanth S. Gadad
- Center of Emphasis in Cancer, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USA
| | - Chinnaswamy Jagannath
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute & Weill Cornell Medical College, Houston, TX 77030, USA
| | - Subramanian Dhandayuthapani
- Center of Emphasis in Infectious Diseases, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX 79905, USA
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3
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Banerjee A, Chakraborty M, Sharma S, Chaturvedi R, Bose A, Biswas P, Singh A, Visweswariah SS. Cyclic AMP binding to a universal stress protein in Mycobacterium tuberculosis is essential for viability. J Biol Chem 2024; 300:107287. [PMID: 38636658 PMCID: PMC11107214 DOI: 10.1016/j.jbc.2024.107287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/20/2024] Open
Abstract
Mycobacterial genomes encode multiple adenylyl cyclases and cAMP effector proteins, underscoring the diverse ways these bacteria utilize cAMP. We identified universal stress proteins, Rv1636 and MSMEG_3811 in Mycobacterium tuberculosis and Mycobacterium smegmatis, respectively, as abundantly expressed, novel cAMP-binding proteins. Rv1636 is secreted via the SecA2 secretion system in M. tuberculosis but is not directly responsible for the efflux of cAMP from the cell. In slow-growing mycobacteria, intrabacterial concentrations of Rv1636 were equivalent to the concentrations of cAMP present in the cell. In contrast, levels of intrabacterial MSMEG_3811 in M. smegmatis were lower than that of cAMP and therefore, overexpression of Rv1636 increased levels of "bound" cAMP. While msmeg_3811 could be readily deleted from the genome of M. smegmatis, we found that the rv1636 gene is essential for the viability of M. tuberculosis and is dependent on the cAMP-binding ability of Rv1636. Therefore, Rv1636 may function to regulate cAMP signaling by direct sequestration of the second messenger. This is the first evidence of a "sponge" for any second messenger in bacterial signaling that would allow mycobacterial cells to regulate the available intrabacterial "free" pool of cAMP.
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Affiliation(s)
- Arka Banerjee
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, India
| | - Moubani Chakraborty
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, India
| | - Suruchi Sharma
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, India
| | - Ruchi Chaturvedi
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bengaluru, India
| | - Avipsa Bose
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, India
| | - Priyanka Biswas
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bengaluru, India
| | - Sandhya S Visweswariah
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bengaluru, India.
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4
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Palande A, Patil S, Veeram A, Sahoo SS, Lodhiya T, Maurya P, Muralikrishnan B, Chugh J, Mukherjee R. Proteomic Analysis of the Mycobacterium tuberculosis Outer Membrane for Potential Implications in Uptake of Small Molecules. ACS Infect Dis 2024; 10:890-906. [PMID: 38400924 DOI: 10.1021/acsinfecdis.3c00517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2024]
Abstract
Increased resistance to current antimycobacterial agents and a potential bias toward relatively hydrophobic chemical entities highlight an urgent need to understand how current anti-TB drugs enter the tubercle bacilli. While inner membrane proteins are well-studied, how small molecules cross the impenetrable outer membrane remains unknown. Here, we employed mass spectrometry-based proteomics to show that octyl-β-d-glucopyranoside selectively extracts the outer membrane proteins of Mycobacterium tuberculosis. Differentially expressed proteins between nutrient-replete and nutrient-depleted conditions were enriched to identify proteins involved in nutrient uptake. We demonstrate cell surface localization of seven new proteins using immunofluorescence and show that overexpression of the proteins LpqY and ProX leads to hypersensitivity toward streptomycin, while overexpression of SubI, SpmT, and Rv2041 exhibited higher membrane permeability, assessed through an EtBr accumulation assay. Further, proton NMR metabolomics suggests the role of six outer membrane proteins in glycerol uptake. This study identifies several outer membrane proteins that are involved in the permeation of small hydrophilic molecules and are potential targets for enhancing the uptake and efficacy of anti-TB drugs.
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Affiliation(s)
- Aseem Palande
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Saniya Patil
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Anjali Veeram
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Soumya Swastik Sahoo
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Pune 411008, India
| | - Tejan Lodhiya
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Pankaj Maurya
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Balaji Muralikrishnan
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Jeetender Chugh
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Pune 411008, India
| | - Raju Mukherjee
- Department of Biology, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
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5
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Granados-Tristán AL, Hernández-Luna CE, González-Escalante LA, Camacho-Moll ME, Silva-Ramírez B, Bermúdez de León M, Peñuelas-Urquides K. ESX-3 secretion system in Mycobacterium: An overview. Biochimie 2024; 216:46-55. [PMID: 37879428 DOI: 10.1016/j.biochi.2023.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 09/26/2023] [Accepted: 10/22/2023] [Indexed: 10/27/2023]
Abstract
Mycobacteria are microorganisms distributed in the environment worldwide, and some of them, such as Mycobacterium tuberculosis or M. leprae, are pathogenic. The hydrophobic mycobacterial cell envelope has low permeation and bacteria need to export products across their structure. Mycobacteria possess specialized protein secretion systems, such as the Early Secretory Antigenic Target 6 secretion (ESX) system. Five ESX loci have been described in M. tuberculosis, called ESX-1 to ESX-5. The ESX-3 secretion system has been associated with mycobacterial metabolism and growth. The locus of this system is highly conserved across mycobacterial species. Metallo-proteins regulate negative ESX-3 transcription in high conditions of iron and zinc. Moreover, this secretion system is part of an antioxidant regulatory pathway linked to Zinc. EccA3, EccB3, EccC3, EccD3, and EccE3 are components of the ESX-3 secretion machinery, whereas EsxG-EsxH, PE5-PPE4, and PE15-PPE20 are proteins secreted by this system. In addition, EspG3 and MycP3 are complementary proteins involved in transport and proteolysis respectively. This system is associated to mycobacterial virulence by releasing the bacteria from the phagosome and inhibiting endomembrane damage response. Furthermore, components of this system inhibit the host immune response by reducing the recognition of M. tuberculosis-infected cells. The components of the ESX-3 secretion system play a role in drug resistance and cell wall integrity. Moreover, the expression data of this system indicated that external and internal factors affect ESX-3 locus expression. This review provides an overview of new findings on the ESX-3 secretion system, its regulation, expression, and functions.
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Affiliation(s)
- Ana Laura Granados-Tristán
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, 64720, Nuevo León, Mexico; Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, San Nicolás de los Garza, 66455, Nuevo León, Mexico.
| | - Carlos Eduardo Hernández-Luna
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, San Nicolás de los Garza, 66455, Nuevo León, Mexico.
| | - Laura Adiene González-Escalante
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, 64720, Nuevo León, Mexico.
| | - María Elena Camacho-Moll
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, 64720, Nuevo León, Mexico.
| | - Beatriz Silva-Ramírez
- Departamento de Inmunogenética, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, 64720, Nuevo León, Mexico.
| | - Mario Bermúdez de León
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, 64720, Nuevo León, Mexico.
| | - Katia Peñuelas-Urquides
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, 64720, Nuevo León, Mexico.
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Malakar B, Chauhan K, Sanyal P, Naz S, Kalam H, Vivek-Ananth RP, Singh LV, Samal A, Kumar D, Nandicoori VK. Phosphorylation of CFP10 modulates Mycobacterium tuberculosis virulence. mBio 2023; 14:e0123223. [PMID: 37791794 PMCID: PMC10653824 DOI: 10.1128/mbio.01232-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/25/2023] [Indexed: 10/05/2023] Open
Abstract
IMPORTANCE Secreted virulence factors play a critical role in bacterial pathogenesis. Virulence effectors not only help bacteria to overcome the host immune system but also aid in establishing infection. Mtb, which causes tuberculosis in humans, encodes various virulence effectors. Triggers that modulate the secretion of virulence effectors in Mtb are yet to be fully understood. To gain mechanistic insight into the secretion of virulence effectors, we performed high-throughput proteomic studies. With the help of system-level protein-protein interaction network analysis and empirical validations, we unravelled a link between phosphorylation and secretion. Taking the example of the well-known virulence factor of CFP10, we show that the dynamics of CFP10 phosphorylation strongly influenced bacterial virulence and survival ex vivo and in vivo. This study presents the role of phosphorylation in modulating the secretion of virulence factors.
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Affiliation(s)
- Basanti Malakar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Komal Chauhan
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Priyadarshini Sanyal
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Centre for Cellular and Molecular Biology Campus, Hyderabad, India
| | - Saba Naz
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Haroon Kalam
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - R. P. Vivek-Ananth
- The Institute of Mathematical Sciences (IMSc), Homi Bhabha National Institute (HBNI), Chennai, India
| | - Lakshya Veer Singh
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Areejit Samal
- The Institute of Mathematical Sciences (IMSc), Homi Bhabha National Institute (HBNI), Chennai, India
| | - Dhiraj Kumar
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Vinay Kumar Nandicoori
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Centre for Cellular and Molecular Biology Campus, Hyderabad, India
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7
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Maxson ME, Das L, Goldberg MF, Porcelli SA, Chan J, Jacobs WR. Mycobacterium tuberculosis Central Metabolism Is Key Regulator of Macrophage Pyroptosis and Host Immunity. Pathogens 2023; 12:1109. [PMID: 37764917 PMCID: PMC10535942 DOI: 10.3390/pathogens12091109] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/17/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023] Open
Abstract
Metabolic dysregulation in Mycobacterium tuberculosis results in increased macrophage apoptosis or pyroptosis. However, mechanistic links between Mycobacterium virulence and bacterial metabolic plasticity remain ill defined. In this study, we screened random transposon insertions of M. bovis BCG to identify mutants that induce pyroptotic death of the infected macrophage. Analysis of the transposon insertion sites identified a panel of fdr (functioning death repressor) genes, which were shown in some cases to encode functions central to Mycobacterium metabolism. In-depth studies of one fdr gene, fdr8 (BCG3787/Rv3727), demonstrated its important role in the maintenance of M. tuberculosis and M. bovis BCG redox balance in reductive stress conditions in the host. Our studies expand the subset of known Mycobacterium genes linking bacterial metabolic plasticity to virulence and also reveal that the broad induction of pyroptosis by an intracellular bacterial pathogen is linked to enhanced cellular immunity in vivo.
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Affiliation(s)
- Michelle E. Maxson
- Program in Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada;
| | - Lahari Das
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (L.D.); (S.A.P.)
| | | | - Steven A. Porcelli
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (L.D.); (S.A.P.)
| | - John Chan
- Department of Medicine, New Jersey Medical School, 205 South Orange Avenue, Newark, NJ 07103, USA;
| | - William R. Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (L.D.); (S.A.P.)
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8
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Shee S, Veetil RT, Mohanraj K, Das M, Malhotra N, Bandopadhyay D, Beig H, Birua S, Niphadkar S, Nagarajan SN, Sinha VK, Thakur C, Rajmani RS, Chandra N, Laxman S, Singh M, Samal A, Seshasayee AN, Singh A. Biosensor-integrated transposon mutagenesis reveals rv0158 as a coordinator of redox homeostasis in Mycobacterium tuberculosis. eLife 2023; 12:e80218. [PMID: 37642294 PMCID: PMC10501769 DOI: 10.7554/elife.80218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is evolutionarily equipped to resist exogenous reactive oxygen species (ROS) but shows vulnerability to an increase in endogenous ROS (eROS). Since eROS is an unavoidable consequence of aerobic metabolism, understanding how Mtb manages eROS levels is essential yet needs to be characterized. By combining the Mrx1-roGFP2 redox biosensor with transposon mutagenesis, we identified 368 genes (redoxosome) responsible for maintaining homeostatic levels of eROS in Mtb. Integrating redoxosome with a global network of transcriptional regulators revealed a hypothetical protein (Rv0158) as a critical node managing eROS in Mtb. Disruption of rv0158 (rv0158 KO) impaired growth, redox balance, respiration, and metabolism of Mtb on glucose but not on fatty acids. Importantly, rv0158 KO exhibited enhanced growth on propionate, and the Rv0158 protein directly binds to methylmalonyl-CoA, a key intermediate in propionate catabolism. Metabolite profiling, ChIP-Seq, and gene-expression analyses indicate that Rv0158 manages metabolic neutralization of propionate toxicity by regulating the methylcitrate cycle. Disruption of rv0158 enhanced the sensitivity of Mtb to oxidative stress, nitric oxide, and anti-TB drugs. Lastly, rv0158 KO showed poor survival in macrophages and persistence defect in mice. Our results suggest that Rv0158 is a metabolic integrator for carbon metabolism and redox balance in Mtb.
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Affiliation(s)
- Somnath Shee
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | | | - Karthikeyan Mohanraj
- The Institute of Mathematical Sciences, A CI of Homi Bhabha National InstituteChennaiIndia
| | - Mayashree Das
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | | | | | - Hussain Beig
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Shalini Birua
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Shreyas Niphadkar
- Institute for Stem Cell Science and Regenerative MedicineBangaloreIndia
| | - Sathya Narayanan Nagarajan
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Vikrant Kumar Sinha
- Molecular Biophysics Unit, Indian Institute of Science BangaloreBangaloreIndia
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science BangaloreBangaloreIndia
| | - Raju S Rajmani
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science BangaloreBangaloreIndia
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative MedicineBangaloreIndia
| | - Mahavir Singh
- Molecular Biophysics Unit, Indian Institute of Science BangaloreBangaloreIndia
| | - Areejit Samal
- The Institute of Mathematical Sciences, A CI of Homi Bhabha National InstituteChennaiIndia
| | | | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
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Sharma KK, Singh D, Mohite SV, Williamson PR, Kennedy JF. Metal manipulators and regulators in human pathogens: A comprehensive review on microbial redox copper metalloenzymes "multicopper oxidases and superoxide dismutases". Int J Biol Macromol 2023; 233:123534. [PMID: 36740121 DOI: 10.1016/j.ijbiomac.2023.123534] [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: 11/22/2022] [Revised: 01/17/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
The chemistry of metal ions with human pathogens is essential for their survival, energy generation, redox signaling, and niche dominance. To regulate and manipulate the metal ions, various enzymes and metal chelators are present in pathogenic bacteria. Metalloenzymes incorporate transition metal such as iron, zinc, cobalt, and copper in their reaction centers to perform essential metabolic functions; however, iron and copper have gained more importance. Multicopper oxidases have the ability to perform redox reaction on phenolic substrates with the help of copper ions. They have been reported from Enterobacteriaceae, namely Salmonella enterica, Escherichia coli, and Yersinia enterocolitica, but their role in virulence is still poorly understood. Similarly, superoxide dismutases participate in reducing oxidative stress and allow the survival of pathogens. Their role in virulence and survival is well established in Salmonella typhimurium and Mycobacterium tuberculosis. Further, to ensure survival against stress, like metal starvation or metal toxicity, redox metalloenzymes and metal transportation systems of pathogens actively participate in metal homeostasis. Recently, the omics and protein structure biology studies have helped to predict new targets for regulation the colonization potential of the pathogenic strains. The current review is focused on the major roles of redox metalloenzymes, especially MCOs and SODs of human pathogenic bacteria.
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Affiliation(s)
- Krishna Kant Sharma
- Laboratory of Enzymology and Gut Microbiology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India.
| | - Deepti Singh
- Laboratory of Enzymology and Gut Microbiology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India
| | - Shreya Vishwas Mohite
- Laboratory of Enzymology and Gut Microbiology, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India
| | - Peter R Williamson
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - John F Kennedy
- Chembiotech Laboratories, Advanced Science and Technology Institute, 5 the Croft, Buntsford Drive, Stoke Heath, Bromsgrove, Worcs B60 4JE, UK
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10
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Oh Y, Lee HN, Ko EM, Jeong JA, Park SW, Oh JI. Mycobacterial Regulatory Systems Involved in the Regulation of Gene Expression Under Respiration-Inhibitory Conditions. J Microbiol 2023; 61:297-315. [PMID: 36847970 DOI: 10.1007/s12275-023-00026-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 03/01/2023]
Abstract
Mycobacterium tuberculosis is the causative agent of tuberculosis. M. tuberculosis can survive in a dormant state within the granuloma, avoiding the host-mounting immune attack. M. tuberculosis bacilli in this state show increased tolerance to antibiotics and stress conditions, and thus the transition of M. tuberculosis to the nonreplicating dormant state acts as an obstacle to tuberculosis treatment. M. tuberculosis in the granuloma encounters hostile environments such as hypoxia, nitric oxide, reactive oxygen species, low pH, and nutrient deprivation, etc., which are expected to inhibit respiration of M. tuberculosis. To adapt to and survive in respiration-inhibitory conditions, it is required for M. tuberculosis to reprogram its metabolism and physiology. In order to get clues to the mechanism underlying the entry of M. tuberculosis to the dormant state, it is important to understand the mycobacterial regulatory systems that are involved in the regulation of gene expression in response to respiration inhibition. In this review, we briefly summarize the information regarding the regulatory systems implicated in upregulation of gene expression in mycobacteria exposed to respiration-inhibitory conditions. The regulatory systems covered in this review encompass the DosSR (DevSR) two-component system, SigF partner switching system, MprBA-SigE-SigB signaling pathway, cAMP receptor protein, and stringent response.
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Affiliation(s)
- Yuna Oh
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Ha-Na Lee
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Eon-Min Ko
- Division of Bacterial Disease Research, Center for Infectious Disease Research, Korea Disease Control and Prevention Agency, National Institute of Infectious Diseases, National Institute of Health, Osong, 28159, Republic of Korea
| | - Ji-A Jeong
- Division of Bacterial Disease Research, Center for Infectious Disease Research, Korea Disease Control and Prevention Agency, National Institute of Infectious Diseases, National Institute of Health, Osong, 28159, Republic of Korea
| | - Sae Woong Park
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - Jeong-Il Oh
- Department of Integrated Biological Science, Pusan National University, Busan, 46241, Republic of Korea. .,Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea.
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11
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Sparks IL, Derbyshire KM, Jacobs WR, Morita YS. Mycobacterium smegmatis: The Vanguard of Mycobacterial Research. J Bacteriol 2023; 205:e0033722. [PMID: 36598232 PMCID: PMC9879119 DOI: 10.1128/jb.00337-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The genus Mycobacterium contains several slow-growing human pathogens, including Mycobacterium tuberculosis, Mycobacterium leprae, and Mycobacterium avium. Mycobacterium smegmatis is a nonpathogenic and fast growing species within this genus. In 1990, a mutant of M. smegmatis, designated mc2155, that could be transformed with episomal plasmids was isolated, elevating M. smegmatis to model status as the ideal surrogate for mycobacterial research. Classical bacterial models, such as Escherichia coli, were inadequate for mycobacteria research because they have low genetic conservation, different physiology, and lack the novel envelope structure that distinguishes the Mycobacterium genus. By contrast, M. smegmatis encodes thousands of conserved mycobacterial gene orthologs and has the same cell architecture and physiology. Dissection and characterization of conserved genes, structures, and processes in genetically tractable M. smegmatis mc2155 have since provided previously unattainable insights on these same features in its slow-growing relatives. Notably, tuberculosis (TB) drugs, including the first-line drugs isoniazid and ethambutol, are active against M. smegmatis, but not against E. coli, allowing the identification of their physiological targets. Furthermore, Bedaquiline, the first new TB drug in 40 years, was discovered through an M. smegmatis screen. M. smegmatis has become a model bacterium, not only for M. tuberculosis, but for all other Mycobacterium species and related genera. With a repertoire of bioinformatic and physical resources, including the recently established Mycobacterial Systems Resource, M. smegmatis will continue to accelerate mycobacterial research and advance the field of microbiology.
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Affiliation(s)
- Ian L. Sparks
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Keith M. Derbyshire
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - William R. Jacobs
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Yasu S. Morita
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
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12
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Nisa A, Kipper FC, Panigrahy D, Tiwari S, Kupz A, Subbian S. Different modalities of host cell death and their impact on Mycobacterium tuberculosis infection. Am J Physiol Cell Physiol 2022; 323:C1444-C1474. [PMID: 36189975 PMCID: PMC9662802 DOI: 10.1152/ajpcell.00246.2022] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/16/2022] [Accepted: 09/25/2022] [Indexed: 11/22/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is the pathogen that causes tuberculosis (TB), a leading infectious disease of humans worldwide. One of the main histopathological hallmarks of TB is the formation of granulomas comprised of elaborately organized aggregates of immune cells containing the pathogen. Dissemination of Mtb from infected cells in the granulomas due to host and mycobacterial factors induces multiple cell death modalities in infected cells. Based on molecular mechanism, morphological characteristics, and signal dependency, there are two main categories of cell death: programmed and nonprogrammed. Programmed cell death (PCD), such as apoptosis and autophagy, is associated with a protective response to Mtb by keeping the bacteria encased within dead macrophages that can be readily phagocytosed by arriving in uninfected or neighboring cells. In contrast, non-PCD necrotic cell death favors the pathogen, resulting in bacterial release into the extracellular environment. Multiple types of cell death in the PCD category, including pyroptosis, necroptosis, ferroptosis, ETosis, parthanatos, and PANoptosis, may be involved in Mtb infection. Since PCD pathways are essential for host immunity to Mtb, therapeutic compounds targeting cell death signaling pathways have been experimentally tested for TB treatment. This review summarizes different modalities of Mtb-mediated host cell deaths, the molecular mechanisms underpinning host cell death during Mtb infection, and its potential implications for host immunity. In addition, targeting host cell death pathways as potential therapeutic and preventive approaches against Mtb infection is also discussed.
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Affiliation(s)
- Annuurun Nisa
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Franciele C Kipper
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Dipak Panigrahy
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
- Cancer Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Sangeeta Tiwari
- Department of Biological Sciences, Border Biomedical Research Center (BBRC), University of Texas, El Paso, Texas
| | - Andreas Kupz
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine (AITHM), James Cook University, Townsville, Queensland, Australia
| | - Selvakumar Subbian
- Public Health Research Institute, New Jersey Medical School, Rutgers University, Newark, New Jersey
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13
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Donegan RK, Fu Y, Copeland J, Idga S, Brown G, Hale OF, Mitra A, Yang H, Dailey HA, Niederweis M, Jain P, Reddi AR. Exogenously Scavenged and Endogenously Synthesized Heme Are Differentially Utilized by Mycobacterium tuberculosis. Microbiol Spectr 2022; 10:e0360422. [PMID: 36169423 PMCID: PMC9604157 DOI: 10.1128/spectrum.03604-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 01/12/2023] Open
Abstract
Heme is both an essential cofactor and an abundant source of nutritional iron for the human pathogen Mycobacterium tuberculosis. While heme is required for M. tuberculosis survival and virulence, it is also potentially cytotoxic. Since M. tuberculosis can both synthesize and take up heme, the de novo synthesis of heme and its acquisition from the host may need to be coordinated in order to mitigate heme toxicity. However, the mechanisms employed by M. tuberculosis to regulate heme uptake, synthesis, and bioavailability are poorly understood. By integrating ratiometric heme sensors with mycobacterial genetics, cell biology, and biochemistry, we determined that de novo-synthesized heme is more bioavailable than exogenously scavenged heme, and heme availability signals the downregulation of heme biosynthetic enzyme gene expression. Ablation of heme synthesis does not result in the upregulation of known heme import proteins. Moreover, we found that de novo heme synthesis is critical for survival from macrophage assault. Altogether, our data suggest that mycobacteria utilize heme from endogenous and exogenous sources differently and that targeting heme synthesis may be an effective therapeutic strategy to treat mycobacterial infections. IMPORTANCE Mycobacterium tuberculosis infects ~25% of the world's population and causes tuberculosis (TB), the second leading cause of death from infectious disease. Heme is an essential metabolite for M. tuberculosis, and targeting the unique heme biosynthetic pathway of M. tuberculosis could serve as an effective therapeutic strategy. However, since M. tuberculosis can both synthesize and scavenge heme, it was unclear if inhibiting heme synthesis alone could serve as a viable approach to suppress M. tuberculosis growth and virulence. The importance of this work lies in the development and application of genetically encoded fluorescent heme sensors to probe bioavailable heme in M. tuberculosis and the discovery that endogenously synthesized heme is more bioavailable than exogenously scavenged heme. Moreover, it was found that heme synthesis protected M. tuberculosis from macrophage killing, and bioavailable heme in M. tuberculosis is diminished during macrophage infection. Altogether, these findings suggest that targeting M. tuberculosis heme synthesis is an effective approach to combat M. tuberculosis infections.
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Affiliation(s)
- Rebecca K. Donegan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
- Department of Chemistry, Barnard College, New York, New York, USA
| | - Yibo Fu
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Jacqueline Copeland
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Stanzin Idga
- Department of Pathology, Laura and Isaac Perlmutter Cancer Center, New York University Grossman School of Medicine, New York, New York, USA
| | - Gabriel Brown
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Owen F. Hale
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Avishek Mitra
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Hui Yang
- Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Harry A. Dailey
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Paras Jain
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
- Cell Therapy and Cell Engineering Laboratory, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Amit R. Reddi
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
- Parker Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, Georgia, USA
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14
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Host–Pathogen Interactions of Marine Gram-Positive Bacteria. BIOLOGY 2022; 11:biology11091316. [PMID: 36138795 PMCID: PMC9495620 DOI: 10.3390/biology11091316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Complex interactions between marine Gram-positive pathogens and fish hosts in the marine environment can result in diseases of economically important finfish, which cause economic losses in the aquaculture industry. Understanding how these pathogens interact with the fish host and generate disease will contribute to efficient prophylactic measures and treatments. To our knowledge, there are no systematic reviews on marine Gram-positive pathogens. Therefore, here we reviewed the host–pathogen interactions of marine Gram-positive pathogens from the pathogen-centric and host-centric points of view. Abstract Marine Gram-positive bacterial pathogens, including Renibacterium salmoninarum, Mycobacterium marinum, Nocardia seriolae, Lactococcus garvieae, and Streptococcus spp. cause economic losses in marine fish aquaculture worldwide. Comprehensive information on these pathogens and their dynamic interactions with their respective fish–host systems are critical to developing effective prophylactic measures and treatments. While much is known about bacterial virulence and fish immune response, it is necessary to synthesize the knowledge in terms of host–pathogen interactions as a centerpiece to establish a crucial connection between the intricate details of marine Gram-positive pathogens and their fish hosts. Therefore, this review provides a holistic view and discusses the different stages of the host–pathogen interactions of marine Gram-positive pathogens. Gram-positive pathogens can invade fish tissues, evade the fish defenses, proliferate in the host system, and modulate the fish immune response. Marine Gram-positive pathogens have a unique set of virulence factors that facilitate adhesion (e.g., adhesins, hemagglutination activity, sortase, and capsules), invasion (e.g., toxins, hemolysins/cytolysins, the type VII secretion system, and immune-suppressive proteins), evasion (e.g., free radical quenching, actin-based motility, and the inhibition of phagolysosomal fusion), and proliferation and survival (e.g., heme utilization and siderophore-mediated iron acquisition systems) in the fish host. After infection, the fish host initiates specific innate and adaptive immune responses according to the extracellular or intracellular mechanism of infection. Although efforts have continued to be made in understanding the complex interplay at the host–pathogen interface, integrated omics-based investigations targeting host–pathogen–marine environment interactions hold promise for future research.
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15
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Bar-Oz M, Meir M, Barkan D. Virulence-Associated Secretion in Mycobacterium abscessus. Front Immunol 2022; 13:938895. [PMID: 35880173 PMCID: PMC9308005 DOI: 10.3389/fimmu.2022.938895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Non-tuberculous mycobacteria (NTM) are a heterogeneous group of originally environmental organi3sms, increasingly recognized as pathogens with rising prevalence worldwide. Knowledge of NTM’s mechanisms of virulence is lacking, as molecular research of these bacteria is challenging, sometimes more than that of M. tuberculosis (Mtb), and far less resources are allocated to their investigation. While some of the virulence mechanisms are common to several mycobacteria including Mtb, others NTM species-specific. Among NTMs, Mycobacterium abscessus (Mabs) causes some of the most severe and difficult to treat infections, especially chronic pulmonary infections. Mabs survives and proliferates intracellularly by circumventing host defenses, using multiple mechanisms, many of which remain poorly characterized. Some of these immune-evasion mechanisms are also found in Mtb, including phagosome pore formation, inhibition of phagosome maturation, cytokine response interference and apoptosis delay. While much is known of the role of Mtb-secreted effector molecules in mediating the manipulation of the host response, far less is known of the secreted effector molecules in Mabs. In this review, we briefly summarize the knowledge of secreted effectors in Mtb (such as ESX secretion, SecA2, TAT and others), and draw the parallel pathways in Mabs. We also describe pathways that are unique to Mabs, differentiating it from Mtb. This review will assist researchers interested in virulence-associated secretion in Mabs by providing the knowledge base and framework for their studies.
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Affiliation(s)
- Michal Bar-Oz
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Michal Meir
- The Ruth Rappaport Children’s Hospital, Rambam Medical Center, Haifa, Israel
| | - Daniel Barkan
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- *Correspondence: Daniel Barkan,
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16
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Secretory proteins of
Mycobacterium tuberculosis
and their roles in modulation of host immune responses: focus on therapeutic targets. FEBS J 2022; 289:4146-4171. [DOI: 10.1111/febs.16369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 01/04/2022] [Accepted: 01/21/2022] [Indexed: 12/01/2022]
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17
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Dwivedi M, Bajpai K. The chamber of secretome in Mycobacterium tuberculosis as a potential therapeutic target. Biotechnol Genet Eng Rev 2022; 39:1-44. [PMID: 35613080 DOI: 10.1080/02648725.2022.2076031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mycobacterium tuberculosis (MTB) causes one of the ancient diseases, Tuberculosis, affects people around the globe and its severity can be understood by its classification as a second infectious disease after COVID-19 and the 13th leading cause of death according to a WHO report. Despite having advanced diagnostic approaches and therapeutic strategies, unfortunately, TB is still spreading across the population due to the emergence of drug-resistance MTB and Latent TB infection (LTBI). We are seeking for effective approaches to overcome these hindrances and efficient treatment for this perilous disease. Therefore, there is an urgent need to develop drugs based on operative targeting of the bacterial system that could result in both efficient treatment and lesser emergence of MDR-TB. One such promising target could be the secretory systems and especially the Type 7 secretory system (T7SS-ESX) of Mycobacterium tuberculosis, which is crucial for the secretion of effector proteins as well as in establishing host-pathogen interactions of the tubercle bacilli. The five paralogous ESX systems (ESX-1 to EXS-5) have been observed by in silico genome analysis of MTB, among which ESX-1 and ESX-5 are substantial for virulence and mediating host cellular inflammasome. The bacterium growth and virulence can be modulated by targeting the T7SS. In the present review, we demonstrate the current status of therapeutics against MTB and focus on the function and cruciality of T7SS along with other secretory systems as a promising therapeutic target against Tuberculosis.
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Affiliation(s)
- Manish Dwivedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, India
| | - Kriti Bajpai
- Department of Biotechnology, Himachal Pradesh University, Shimla, India
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18
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Shantal CJN, Juan CC, Lizbeth BUS, Carlos HGJ, Estela GPB. Candida glabrata is a successful pathogen: an artist manipulating the immune response. Microbiol Res 2022; 260:127038. [DOI: 10.1016/j.micres.2022.127038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 04/02/2022] [Accepted: 04/07/2022] [Indexed: 02/07/2023]
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19
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Dai W, Li J, Li Q, Cai J, Su J, Stubenrauch C, Wang J. PncsHub: a platform for annotating and analyzing non-classically secreted proteins in Gram-positive bacteria. Nucleic Acids Res 2022; 50:D848-D857. [PMID: 34551435 PMCID: PMC8728121 DOI: 10.1093/nar/gkab814] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 08/30/2021] [Accepted: 09/07/2021] [Indexed: 12/28/2022] Open
Abstract
From industry to food to health, bacteria play an important role in all facets of life. Some of the most important bacteria have been purposely engineered to produce commercial quantities of antibiotics and therapeutics, and non-classical secretion systems are at the forefront of these technologies. Unlike the classical Sec or Tat pathways, non-classically secreted proteins share few common characteristics and use much more diverse secretion pathways for protein transport. Systematically categorizing and investigating the non-classically secreted proteins will enable a deeper understanding of their associated secretion mechanisms and provide a landscape of the Gram-positive secretion pathway distribution. We therefore developed PncsHub (https://pncshub.erc.monash.edu/), the first universal platform for comprehensively annotating and analyzing Gram-positive bacterial non-classically secreted proteins. PncsHub catalogs 4,914 non-classically secreted proteins, which are delicately categorized into 8 subtypes (including the 'unknown' subtype) and annotated with data compiled from up to 26 resources and visualisation tools. It incorporates state-of-the-art predictors to identify new and homologous non-classically secreted proteins and includes three analytical modules to visualise the relationships between known and putative non-classically secreted proteins. As such, PncsHub aims to provide integrated services for investigating, predicting and identifying non-classically secreted proteins to promote hypothesis-driven laboratory-based experiments.
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Affiliation(s)
- Wei Dai
- School of Computer Science and Information Security, Guilin University of Electronic Technology, Guilin 541004, China
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC 3800, Australia
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325011, China
| | - Jiahui Li
- School of Computer Science and Information Security, Guilin University of Electronic Technology, Guilin 541004, China
| | - Qi Li
- School of Computer Science and Information Security, Guilin University of Electronic Technology, Guilin 541004, China
| | - Jiasheng Cai
- School of Computer Science and Information Security, Guilin University of Electronic Technology, Guilin 541004, China
| | - Jianzhong Su
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325011, China
- School of Ophthalmology & Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou 325027, China
| | - Christopher Stubenrauch
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC 3800, Australia
- Centre to Impact AMR, Monash University, VIC 3800, Australia
| | - Jiawei Wang
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC 3800, Australia
- Centre to Impact AMR, Monash University, VIC 3800, Australia
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20
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Dhungel L, Burcham L, Park JY, Sampathkumar HD, Cudjoe A, Seo KS, Jordan H. Responses to chemical cross-talk between the Mycobacterium ulcerans toxin, mycolactone, and Staphylococcus aureus. Sci Rep 2021; 11:11746. [PMID: 34083568 PMCID: PMC8175560 DOI: 10.1038/s41598-021-89177-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/22/2021] [Indexed: 02/01/2023] Open
Abstract
Buruli ulcer is a neglected tropical disease caused by the environmental pathogen, Mycobacterium ulcerans whose major virulence factor is mycolactone, a lipid cytotoxic molecule. Buruli ulcer has high morbidity, particularly in rural West Africa where the disease is endemic. Data have shown that infected lesions of Buruli ulcer patients can be colonized by quorum sensing bacteria such as Staphylococcus aureus, S. epidermidis, and Pseudomonas aeruginosa, but without typical pathology associated with those pathogens' colonization. M. ulcerans pathogenesis may not only be an individual act but may also be dependent on synergistic or antagonistic mechanisms within a polymicrobial network. Furthermore, co-colonization by these pathogens may promote delayed wound healing, especially after the initiation of antibiotic therapy. Hence, it is important to understand the interaction of M. ulcerans with other bacteria encountered during skin infection. We added mycolactone to S. aureus and incubated for 3, 6 and 24 h. At each timepoint, S. aureus growth and hemolytic activity was measured, and RNA was isolated to measure virulence gene expression through qPCR and RNASeq analyses. Results showed that mycolactone reduced S. aureus hemolytic activity, suppressed hla promoter activity, and attenuated virulence genes, but did not affect S. aureus growth. RNASeq data showed mycolactone greatly impacted S. aureus metabolism. These data are relevant and significant as mycolactone and S. aureus sensing and response at the transcriptional, translational and regulation levels will provide insight into biological mechanisms of interspecific interactions that may play a role in regulation of responses such as effects between M. ulcerans, mycolactone, and S. aureus virulence that will be useful for treatment and prevention.
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Affiliation(s)
- Laxmi Dhungel
- Department of Biological Sciences, Mississippi State University, P.O. Box GY, Starkville, MS, 39762, USA
| | - Lindsey Burcham
- Department of Biological Sciences, Mississippi State University, P.O. Box GY, Starkville, MS, 39762, USA
| | - Joo Youn Park
- Department of Biological Sciences, Mississippi State University, P.O. Box GY, Starkville, MS, 39762, USA
| | - Harshini Devi Sampathkumar
- Department of Biological Sciences, Mississippi State University, P.O. Box GY, Starkville, MS, 39762, USA
| | | | - Keun Seok Seo
- Department of Biological Sciences, Mississippi State University, P.O. Box GY, Starkville, MS, 39762, USA
| | - Heather Jordan
- Department of Biological Sciences, Mississippi State University, P.O. Box GY, Starkville, MS, 39762, USA.
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21
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Rankine-Wilson LI, Shapira T, Sao Emani C, Av-Gay Y. From infection niche to therapeutic target: the intracellular lifestyle of Mycobacterium tuberculosis. MICROBIOLOGY (READING, ENGLAND) 2021; 167:001041. [PMID: 33826491 PMCID: PMC8289223 DOI: 10.1099/mic.0.001041] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/15/2021] [Indexed: 12/16/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is an obligate human pathogen killing millions of people annually. Treatment for tuberculosis is lengthy and complicated, involving multiple drugs and often resulting in serious side effects and non-compliance. Mtb has developed numerous complex mechanisms enabling it to not only survive but replicate inside professional phagocytes. These mechanisms include, among others, overcoming the phagosome maturation process, inhibiting the acidification of the phagosome and inhibiting apoptosis. Within the past decade, technologies have been developed that enable a more accurate understanding of Mtb physiology within its intracellular niche, paving the way for more clinically relevant drug-development programmes. Here we review the molecular biology of Mtb pathogenesis offering a unique perspective on the use and development of therapies that target Mtb during its intracellular life stage.
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Affiliation(s)
| | - Tirosh Shapira
- Division of Infectious Disease, Department of Medicine, The University of British Columbia, Vancouver, Canada
| | - Carine Sao Emani
- Division of Infectious Disease, Department of Medicine, The University of British Columbia, Vancouver, Canada
| | - Yossef Av-Gay
- Department of Microbiology & Immunology, The University of British Columbia, Vancouver, Canada
- Division of Infectious Disease, Department of Medicine, The University of British Columbia, Vancouver, Canada
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22
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" Candidatus Liberibacter asiaticus" Secretes Nonclassically Secreted Proteins That Suppress Host Hypersensitive Cell Death and Induce Expression of Plant Pathogenesis-Related Proteins. Appl Environ Microbiol 2021; 87:AEM.00019-21. [PMID: 33579681 PMCID: PMC8091116 DOI: 10.1128/aem.00019-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although emerging evidence indicates that bacteria extracellularly export many cytoplasmic proteins referred to as non-classically secreted proteins (ncSecPs) for their own benefit, the mechanisms and functional significance of the ncSecPs in extracellular milieu remain elusive. "Candidatus Liberibacter asiaticus" (CLas) is a fastidious Gram-negative bacterium that causes Huanglongbing (HLB), the most globally devastating citrus disease. In this study, using the SecretomeP program coupled with an Escherichia coli alkaline phosphatase assay, we identified 27 ncSecPs from the CLas genome. Further, we demonstrated that 10 of these exhibited significantly higher levels of gene expression in citrus than in psyllid hosts, and particularly suppressed hypersensitive response (HR)-based cell death and H2O2 overaccumulation in Nicotiana benthamiana, indicating their opposing effects on early plant defenses. However, these proteins also dramatically enhanced the gene expression of pathogenesis-related 1 protein (PR-1), PR-2, and PR-5, essential components of plant defense mechanisms. Additional experiments disclosed that the increased expression of these PR genes, in particular PR-1 and PR-5, could negatively regulate HR-based cell death development and H2O2 accumulation. Remarkably, CLas infection clearly induced gene expression of PR-1, PR-2, and PR-5 in both HLB-tolerant and HLB-susceptible species of citrus plants. Taken together, we hypothesized that CLas has evolved an arsenal of ncSecPs that function cooperatively to overwhelm the early plant defenses by inducing host PR genes.IMPORTANCE In this study, we present a combined computational and experimental methodology that allows a rapid and efficient identification of the ncSecPs from bacteria, in particular the unculturable bacteria like CLas. Meanwhile, the study determined that a number of CLas ncSecPs suppressed HR-based cell death, and thus indicated a novel role for the bacterial ncSecPs in extracellular milieu. More importantly, these ncSecPs were found to suppress cell death presumably by utilizing host PR proteins. The data overall provide a novel clue to understand the CLas pathogenesis and also suggest a new way by which phytopathogens manipulate host cellular machinery to establish infection.
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23
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Augenstreich J, Briken V. Host Cell Targets of Released Lipid and Secreted Protein Effectors of Mycobacterium tuberculosis. Front Cell Infect Microbiol 2020; 10:595029. [PMID: 33194845 PMCID: PMC7644814 DOI: 10.3389/fcimb.2020.595029] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a very successful pathogen, strictly adapted to humans and the cause of tuberculosis. Its success is associated with its ability to inhibit host cell intrinsic immune responses by using an arsenal of virulence factors of different nature. It has evolved to synthesize a series of complex lipids which form an outer membrane and may also be released to enter host cell membranes. In addition, secreted protein effectors of Mtb are entering the host cell cytosol to interact with host cell proteins. We briefly discuss the current model, involving the ESX-1 type seven secretion system and the Mtb lipid phthiocerol dimycoserosate (PDIM), of how Mtb creates pores in the phagosomal membrane to allow Mtb proteins to access to the host cell cytosol. We provide an exhaustive list of Mtb secreted proteins that have effector functions. They modify (mostly inhibit but sometimes activate) host cell pathways such as: phagosome maturation, cell death, cytokine response, xenophagy, reactive oxygen species (ROS) response via NADPH oxidase 2 (NOX2), nitric oxide (NO) response via NO Synthase 2 (NOS2) and antigen presentation via MHC class I and class II molecules. We discuss the host cell targets for each lipid and protein effector and the importance of the Mtb effector for virulence of the bacterium.
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Affiliation(s)
| | - Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
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24
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Patil S, Palande A, Lodhiya T, Pandit A, Mukherjee R. Redefining genetic essentiality in Mycobacterium tuberculosis. Gene 2020; 765:145091. [PMID: 32898604 DOI: 10.1016/j.gene.2020.145091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/18/2020] [Accepted: 08/21/2020] [Indexed: 11/15/2022]
Abstract
Sequencing transposon mutant libraries have been pivotal in annotating essential and non-essential genes in bacteria. This is particularly very helpful in the case of Mycobacterium tuberculosis with a large part of its genome without known function. It is not known whether there are any variations in the essentiality states as a function of optimal growth in the absence of any selection pressure. We here grow a high-density mutant library of M. tuberculosis through serial cultures and monitor the temporal fluctuations in insertion frequencies across all TA dinucleotides in the genome. Genes that cause morphological and physiological heterogeneity or enable metabolic bypass were found to gradually lose insertions, while genes comprising the toxin-antitoxin systems were found to get enriched with insertions during growth in nutrient replete conditions. High levels of fluctuations were observed in genes involved in cell wall and cell processes, intermediary metabolism, and genes involved in virulence, suggesting new modes of adaptation undertaken by the mutants. We also report the essentiality status of several newly annotated genetic features.
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Affiliation(s)
- Saniya Patil
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India
| | - Aseem Palande
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India
| | - Tejan Lodhiya
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India
| | - Awadhesh Pandit
- National Center for Biological Sciences, Bengaluru 560065, India
| | - Raju Mukherjee
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India.
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25
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Lindič N, Loboda J, Usenik A, Vidmar R, Turk D. The Structure of Clostridioides difficile SecA2 ATPase Exposes Regions Responsible for Differential Target Recognition of the SecA1 and SecA2-Dependent Systems. Int J Mol Sci 2020; 21:ijms21176153. [PMID: 32858965 PMCID: PMC7503281 DOI: 10.3390/ijms21176153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 11/17/2022] Open
Abstract
SecA protein is a major component of the general bacterial secretory system. It is an ATPase that couples nucleotide hydrolysis to protein translocation. In some Gram-positive pathogens, a second paralogue, SecA2, exports a different set of substrates, usually virulence factors. To identify SecA2 features different from SecA(1)s, we determined the crystal structure of SecA2 from Clostridioides difficile, an important nosocomial pathogen, in apo and ATP-γ-S-bound form. The structure reveals a closed monomer lacking the C-terminal tail (CTT) with an otherwise similar multidomain organization to its SecA(1) homologues and conserved binding of ATP-γ-S. The average in vitro ATPase activity rate of C. difficile SecA2 was 2.6 ± 0.1 µmolPi/min/µmol. Template-based modeling combined with evolutionary conservation analysis supports a model where C. difficile SecA2 in open conformation binds the target protein, ensures its movement through the SecY channel, and enables dimerization through PPXD/HWD cross-interaction of monomers during the process. Both approaches exposed regions with differences between SecA(1) and SecA2 homologues, which are in agreement with the unique adaptation of SecA2 proteins for a specific type of substrate, a role that can be addressed in further studies.
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Affiliation(s)
- Nataša Lindič
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (N.L.); (J.L.); (A.U.); (R.V.)
| | - Jure Loboda
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (N.L.); (J.L.); (A.U.); (R.V.)
| | - Aleksandra Usenik
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (N.L.); (J.L.); (A.U.); (R.V.)
- Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins (CIPKeBiP), Jamova Cesta 39, 1000 Ljubljana, Slovenia
| | - Robert Vidmar
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (N.L.); (J.L.); (A.U.); (R.V.)
| | - Dušan Turk
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (N.L.); (J.L.); (A.U.); (R.V.)
- Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins (CIPKeBiP), Jamova Cesta 39, 1000 Ljubljana, Slovenia
- Correspondence: ; Tel.: +386-1-477-3857
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26
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A multilayered repair system protects the mycobacterial chromosome from endogenous and antibiotic-induced oxidative damage. Proc Natl Acad Sci U S A 2020; 117:19517-19527. [PMID: 32727901 DOI: 10.1073/pnas.2006792117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Oxidative damage to DNA is a threat to the genomic integrity and coding accuracy of the chromosomes of all living organisms. Guanine is particularly susceptible to oxidation, and 8-oxo-dG (OG), when produced in situ or incorporated by DNA polymerases, is highly mutagenic due to mispairing with adenine. In many bacteria, defense against OG depends on MutT enzymes, which sanitize OG in the nucleotide pool, and the MutM/Y system, which counteracts OG in chromosomal DNA. In Escherichia coli, antibiotic lethality has been linked to oxidative stress and the downstream consequences of OG processing. However, in mycobacteria, the role of these systems in genomic integrity and antibiotic lethality is not understood, in part because mycobacteria encode four MutT enzymes and two MutMs, suggesting substantial redundancy. Here, we definitively probe the role of OG handling systems in mycobacteria. We find that, although MutT4 is the only MutT enzyme required for resistance to oxidative stress, this effect is not due to OG processing. We find that the dominant system that defends against OG-mediated mutagenesis is MutY/MutM1, and this system is dedicated to in situ chromosomal oxidation rather than correcting OG incorporated by accessory polymerases (DinB1/DinB2/DinB3/DnaE2). In addition, we uncover that mycobacteria resist antibiotic lethality through nucleotide sanitization by MutTs, and in the absence of this system, accessory DNA polymerases and MutY/M contribute to antibiotic-induced lethality. These results reveal a complex, multitiered system of OG handling in mycobacteria with roles in oxidative stress resistance, mutagenesis, and antibiotic lethality.
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27
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Del Val C, Bondar AN. Diversity and sequence motifs of the bacterial SecA protein motor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183319. [PMID: 32335021 DOI: 10.1016/j.bbamem.2020.183319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/17/2020] [Accepted: 04/19/2020] [Indexed: 12/24/2022]
Abstract
SecA is an essential component of the Sec protein secretion pathway in bacteria. Secretory proteins targeted to the Sec pathway by their N-terminal signal peptide bind to SecA, which couples binding and hydrolysis of adenosine triphosphate with movement of the secretory protein across the membrane-embedded SecYEG protein translocon. The phylogenetic diversity of bacteria raises the important question as to whether the region of SecA where the pre-protein binds has conserved sequence features that might impact the reaction mechanism of SecA. To address this question we established a large data set of SecA protein sequences and implemented a protocol to cluster and analyze these sequences according to features of two of the SecA functional domains, the protein binding domain and the nucleotide-binding domain 1. We identify remarkable sequence diversity of the protein binding domain, but also conserved motifs with potential role in protein binding. The N-terminus of SecA has sequence motifs that could help anchor SecA to the membrane. The overall sequence length and net estimated charge of SecA sequences depend on the organism.
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Affiliation(s)
- Coral Del Val
- University of Granada, Departmrent of Computer Science and Artificial Intelligence, E-18071 Granada, Spain; University of Granada, Andalusian Research Institute in Data Science and Computational Intelligence, E-18071 Granada, Spain.
| | - Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, D-14195 Berlin, Germany.
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28
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Lochab S, Singh Y, Sengupta S, Nandicoori VK. Mycobacterium tuberculosis exploits host ATM kinase for survival advantage through SecA2 secretome. eLife 2020; 9:51466. [PMID: 32223892 PMCID: PMC7162654 DOI: 10.7554/elife.51466] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 03/27/2020] [Indexed: 11/13/2022] Open
Abstract
(Mtb) produces inflections in the host signaling networks to create a favorable milieu for survival. The virulent Mtb strain, Rv caused double strand breaks (DSBs), whereas the non-virulent Ra strain triggered single-stranded DNA generation. The effectors secreted by SecA2 pathway were essential and adequate for the genesis of DSBs. Accumulation of DSBs mediated through Rv activates ATM-Chk2 pathway of DNA damage response (DDR) signaling, resulting in altered cell cycle. Instead of the classical ATM-Chk2 DDR, Mtb gains survival advantage through ATM-Akt signaling cascade. Notably, in vivo infection with Mtb led to sustained DSBs and ATM activation during chronic phase of tuberculosis. Addition of ATM inhibitor enhances isoniazid mediated Mtb clearance in macrophages as well as in murine infection model, suggesting its utility for host directed adjunct therapy. Collectively, data suggests that DSBs inflicted by SecA2 secretome of Mtb provides survival niche through activation of ATM kinase.
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Affiliation(s)
- Savita Lochab
- National Institute of Immunology, New Delhi, India.,Department of Zoology, University of Delhi, New Delhi, India
| | - Yogendra Singh
- Department of Zoology, University of Delhi, New Delhi, India
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29
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Abstract
Tuberculosis (TB) is a serious global public health challenge that results in significant morbidity and mortality worldwide. TB is caused by infection with the bacilli Mycobacterium tuberculosis (M. tuberculosis), which has evolved a wide variety of strategies in order to thrive within its host. Understanding the complex interactions between M. tuberculosis and host immunity can inform the rational design of better TB vaccines and therapeutics. This chapter covers innate and adaptive immunity against M. tuberculosis infection, including insights on bacterial immune evasion and subversion garnered from animal models of infection and human studies. In addition, this chapter discusses the immunology of the TB granuloma, TB diagnostics, and TB comorbidities. Finally, this chapter provides a broad overview of the current TB vaccine pipeline.
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30
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Abstract
In addition to SecA of the general Sec system, many Gram-positive bacteria, including mycobacteria, express SecA2, a second, transport-associated ATPase. SecA2s can be subdivided into two mechanistically distinct types: (i) SecA2s that are part of the accessory Sec (aSec) system, a specialized transporter mediating the export of a family of serine-rich repeat (SRR) glycoproteins that function as adhesins, and (ii) SecA2s that are part of multisubstrate systems, in which SecA2 interacts with components of the general Sec system, specifically the SecYEG channel, to export multiple types of substrates. Found mainly in streptococci and staphylococci, the aSec system also contains SecY2 and novel accessory Sec proteins (Asps) that are required for optimal export. Asp2 also acetylates glucosamine residues on the SRR domains of the substrate during transport. Targeting of the SRR substrate to SecA2 and the aSec translocon is mediated by a specialized signal peptide. Multisubstrate SecA2 systems are present in mycobacteria, corynebacteria, listeriae, clostridia, and some bacillus species. Although most substrates for this SecA2 have canonical signal peptides that are required for export, targeting to SecA2 appears to depend on structural features of the mature protein. The feature of the mature domains of these proteins that renders them dependent on SecA2 for export may be their potential to fold in the cytoplasm. The discovery of aSec and multisubstrate SecA2 systems expands our appreciation of the diversity of bacterial export pathways. Here we present our current understanding of the mechanisms of each of these SecA2 systems.
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31
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Principle and potential applications of the non-classical protein secretory pathway in bacteria. Appl Microbiol Biotechnol 2019; 104:953-965. [PMID: 31853566 DOI: 10.1007/s00253-019-10285-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 10/22/2019] [Accepted: 10/27/2019] [Indexed: 12/15/2022]
Abstract
In addition to the extracellular proteins secreted by known secretory pathways, a number of cytoplasmic proteins without predicable or known signal sequences or secretory motifs have been found in the extracellular milieu, and were consequently classified as non-classically secreted proteins. Non-classical protein secretion is considered to be a general, conserved cellular phenomenon in both eukaryotes and prokaryotes. There are several research hotspots on the non-classical protein secretory pathway, and the most important two of them are the recognition principle of substrate proteins and possible secretory mechanisms. To date, researchers have made some progress in understanding the characteristics of these proteins. For example, it was discovered that many non-classically secreted proteins exist and are secreted in multimeric form. Some of these proteins prefer to be clustered and exported at the poles and the septum of the cell. The majority of these proteins play different functions when they are in the intra- and extracellular environments, and several of their functions are related to survival and pathogenicity. Furthermore, non-classically secreted proteins can be used as leading proteins to guide a POI (protein of interest) out of the cells, which provides a novel strategy for protein secretion with potential applications in the industry. Summarizing these findings, this review emphasizes the hot spots related to non-classically secreted proteins in bacteria, lists the most important hypotheses on the selection and secretion mechanisms of non-classically secreted proteins, and put forward their potential applications.
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32
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Kroesen VM, Madacki J, Frigui W, Sayes F, Brosch R. Mycobacterial virulence: impact on immunogenicity and vaccine research. F1000Res 2019; 8. [PMID: 32047597 PMCID: PMC6979476 DOI: 10.12688/f1000research.20572.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/21/2019] [Indexed: 12/17/2022] Open
Abstract
The borderline between virulence and efficacy in live attenuated vaccine strains is often blurred and this is also the case for the Bacillus Calmette–Guérin (BCG), the only currently licensed anti-tuberculosis vaccine used on a large, global scale, which was obtained almost 100 years ago. While BCG is more than 99% identical at the genome level to
Mycobacterium tuberculosis, the causative pathogen of human tuberculosis, some important differences in virulence factors cause naturally irreversible attenuation and safety of this vaccine in the immunocompetent host. Some of these virulence factors are involved in persistence capacities of the vaccine strains and also represent strong immunogens, responsible for inducing different host signaling pathways, which have to be taken into consideration for the development of revised and new vaccine strains. Here we discuss a number of selected mycobacterial features in relation to their biological functions and potential impact on virulence and vaccine efficacy.
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Affiliation(s)
- Vera M Kroesen
- Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR 3525, Institut Pasteur, Paris, France.,Faculty VI, University of Oldenburg, Oldenburg, Germany
| | - Jan Madacki
- Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR 3525, Institut Pasteur, Paris, France
| | - Wafa Frigui
- Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR 3525, Institut Pasteur, Paris, France
| | - Fadel Sayes
- Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR 3525, Institut Pasteur, Paris, France
| | - Roland Brosch
- Unit for Integrated Mycobacterial Pathogenomics, CNRS UMR 3525, Institut Pasteur, Paris, France
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33
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van Winden VJC, Houben ENG, Braunstein M. Protein Export into and across the Atypical Diderm Cell Envelope of Mycobacteria. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0043-2018. [PMID: 31400094 PMCID: PMC10957183 DOI: 10.1128/microbiolspec.gpp3-0043-2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Indexed: 02/07/2023] Open
Abstract
Mycobacteria, including the infamous pathogen Mycobacterium tuberculosis, are high-GC Gram-positive bacteria with a distinctive cell envelope. Although there is a typical inner membrane, the mycobacterial cell envelope is unusual in having its peptidoglycan layer connected to a polymer of arabinogalactan, which in turn is covalently attached to long-chain mycolic acids that help form a highly impermeable mycobacterial outer membrane. This complex double-membrane, or diderm, cell envelope imparts mycobacteria with unique requirements for protein export into and across the cell envelope for secretion into the extracellular environment. In this article, we review the four protein export pathways known to exist in mycobacteria: two conserved systems that exist in all types of bacteria (the Sec and Tat pathways) and two specialized systems that exist in mycobacteria, corynebacteria, and a subset of low-GC Gram-positive bacteria (the SecA2 and type VII secretion pathways). We describe the progress made over the past 15 years in understanding each of these mycobacterial export pathways, and we highlight the need for research to understand the specific steps of protein export across the mycobacterial outer membrane.
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Affiliation(s)
- Vincent J C van Winden
- Department of Medical Microbiology and Infection Control, Amsterdam UMC, Vrije Universiteit, Amsterdam, The Netherlands
| | - Edith N G Houben
- Section of Molecular Microbiology, Amsterdam Institute for Molecules, Medicines, and Systems, Vrije Universiteit, Amsterdam, The Netherlands
| | - Miriam Braunstein
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599
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34
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Piacenza L, Trujillo M, Radi R. Reactive species and pathogen antioxidant networks during phagocytosis. J Exp Med 2019; 216:501-516. [PMID: 30792185 PMCID: PMC6400530 DOI: 10.1084/jem.20181886] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/04/2019] [Accepted: 02/04/2019] [Indexed: 11/23/2022] Open
Abstract
This review discusses the generation of phagosomal cytotoxic reactive species by activated macrophages and neutrophils for the control of intracellular pathogens, and the mechanisms by which microbes combat host-derived oxidants via antioxidant networks that mitigate the redox-dependent control of infection. The generation of phagosomal cytotoxic reactive species (i.e., free radicals and oxidants) by activated macrophages and neutrophils is a crucial process for the control of intracellular pathogens. The chemical nature of these species, the reactions they are involved in, and the subsequent effects are multifaceted and depend on several host- and pathogen-derived factors that influence their production rates and catabolism inside the phagosome. Pathogens rely on an intricate and synergistic antioxidant armamentarium that ensures their own survival by detoxifying reactive species. In this review, we discuss the generation, kinetics, and toxicity of reactive species generated in phagocytes, with a focus on the response of macrophages to internalized pathogens and concentrating on Mycobacterium tuberculosis and Trypanosoma cruzi as examples of bacterial and parasitic infection, respectively. The ability of pathogens to deal with host-derived reactive species largely depends on the competence of their antioxidant networks at the onset of invasion, which in turn can tilt the balance toward pathogen survival, proliferation, and virulence over redox-dependent control of infection.
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Affiliation(s)
- Lucía Piacenza
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay .,Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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35
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Mycobacteria and their sweet proteins: An overview of protein glycosylation and lipoglycosylation in M. tuberculosis. Tuberculosis (Edinb) 2019; 115:1-13. [PMID: 30948163 DOI: 10.1016/j.tube.2019.01.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 12/16/2022]
Abstract
Post-translational modifications represent a key aspect of enzyme and protein regulation and function. Post-translational modifications are involved in signaling and response to stress, adaptation to changing environments, regulation of toxic and damaged proteins, proteins localization and host-pathogen interactions. Glycosylation in Mycobacterium tuberculosis (Mtb), is a post-translational modification often found in conjunction with acylation in mycobacterial proteins. Since the discovery of glycosylated proteins in the early 1980's, important advances in our understanding of the mechanisms of protein glycosylation have been made. The number of known glycosylated substrates in Mtb has grown through the years, yet many questions remain. This review will explore the current knowledge on protein glycosylation in Mtb, causative agent of Tuberculosis and number one infectious killer in the world. The mechanism and significance of this post-translational modification, as well as maturation, export and acylation of glycosylated proteins will be reviewed. We expect to provide the reader with an overall view of protein glycosylation in Mtb, as well as the significance of this post-translational modification to the physiology and host-pathogen interactions of this important pathogen. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD011081 and 10.6019/PXD011081.
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Advani J, Verma R, Chatterjee O, Devasahayam Arokia Balaya R, Najar MA, Ravishankara N, Suresh S, Pachori PK, Gupta UD, Pinto SM, Chauhan DS, Tripathy SP, Gowda H, Prasad TK. Rise of Clinical Microbial Proteogenomics: A Multiomics Approach to Nontuberculous Mycobacterium—The Case ofMycobacterium abscessusUC22. ACTA ACUST UNITED AC 2019; 23:1-16. [DOI: 10.1089/omi.2018.0116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Jayshree Advani
- Institute of Bioinformatics, International Technology Park, Bangalore, India
- Manipal Academy of Higher Education, Manipal, India
| | - Renu Verma
- Institute of Bioinformatics, International Technology Park, Bangalore, India
| | - Oishi Chatterjee
- Institute of Bioinformatics, International Technology Park, Bangalore, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, India
| | - Rex Devasahayam Arokia Balaya
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Mohd Altaf Najar
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Namitha Ravishankara
- Department of Biotechnology, M.S. Ramaiah Institute of Technology, Bangalore, India
| | - Sneha Suresh
- Department of Biotechnology, M.S. Ramaiah Institute of Technology, Bangalore, India
| | - Praveen Kumar Pachori
- Department of Microbiology and Molecular Biology, ICMR-National JALMA Institute for Leprosy & Other Mycobacterial Diseases, Agra, India
| | - Umesh D. Gupta
- Department of Microbiology and Molecular Biology, ICMR-National JALMA Institute for Leprosy & Other Mycobacterial Diseases, Agra, India
| | - Sneha M. Pinto
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
| | - Devendra S. Chauhan
- Department of Microbiology and Molecular Biology, ICMR-National JALMA Institute for Leprosy & Other Mycobacterial Diseases, Agra, India
| | - Srikanth Prasad Tripathy
- Department of Microbiology and Molecular Biology, ICMR-National JALMA Institute for Leprosy & Other Mycobacterial Diseases, Agra, India
| | - Harsha Gowda
- Institute of Bioinformatics, International Technology Park, Bangalore, India
| | - T.S. Keshava Prasad
- Institute of Bioinformatics, International Technology Park, Bangalore, India
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to be University), Mangalore, India
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37
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Hashish E, Merwad A, Elgaml S, Amer A, Kamal H, Elsadek A, Marei A, Sitohy M. Mycobacterium marinum infection in fish and man: epidemiology, pathophysiology and management; a review. Vet Q 2018; 38:35-46. [PMID: 29493404 PMCID: PMC6831007 DOI: 10.1080/01652176.2018.1447171] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/26/2018] [Indexed: 11/04/2022] Open
Abstract
Mycobacterium marinum is an opportunistic pathogen inducing infection in fresh and marine water fish. This pathogen causes necrotizing granuloma like tuberculosis, morbidity and mortality in fish. The cell wall-associated lipid phthiocerol dimycocerosates, phenolic glycolipids and ESAT-6 secretion system 1 (ESX-1) are the conserved virulence determinant of the organism. Human infections with Mycobacterium marinum hypothetically are classified into four clinical categories (type I-type IV) and have been associated with the exposure of damaged skin to polluted water from fish pools or contacting objects contaminated with infected fish. Fish mycobacteriosis is clinically manifested and characterized in man by purple painless nodules, liable to develop into superficial crusting ulceration with scar formation. Early laboratory diagnosis of M. marinum including histopathology, culture and PCR is essential and critical as the clinical response to antibiotics requires months to be attained. The pathogenicity and virulence determinants of M. marinum need to be thoroughly and comprehensively investigated and understood. In spite of accumulating information on this pathogen, the different relevant data should be compared, connected and globally compiled. This article is reviewing the epidemiology, virulence factors, diagnosis and disease management in fish while casting light on the potential associated public health hazards.
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Affiliation(s)
- Emad Hashish
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, Egypt
| | - Abdallah Merwad
- Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Egypt
| | - Shimaa Elgaml
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, Egypt
| | - Ali Amer
- Tuberculosis Unit, Animal Health Research Institute (AHRI), Giza, Egypt
| | - Huda Kamal
- Department of Meat Hygiene, National Research Center (NRC), Zagazig, Egypt
| | - Ahmed Elsadek
- Immunology Research Lab, Immunology Division, Department of Microbiology and Immunology, Faculty of Medicine, Zagazig University, Egypt
| | - Ayman Marei
- Immunology Research Lab, Immunology Division, Department of Microbiology and Immunology, Faculty of Medicine, Zagazig University, Egypt
| | - Mahmoud Sitohy
- Department of Biochemistry, Faculty of Agriculture, Zagazig University, Egypt
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38
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Mohareer K, Asalla S, Banerjee S. Cell death at the cross roads of host-pathogen interaction in Mycobacterium tuberculosis infection. Tuberculosis (Edinb) 2018; 113:99-121. [PMID: 30514519 DOI: 10.1016/j.tube.2018.09.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/13/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
Tuberculosis (TB) continues to be the leading cause of death by any single infectious agent, accounting for around 1.7 million annual deaths globally, despite several interventions and support programs by national and international agencies. With the development of drug resistance in Mycobacterium tuberculosis (M. tb), there has been a paradigm shift in TB research towards host-directed therapy. The potential targets include the interactions between host and bacterial proteins that are crucial for pathogenesis. Hence, collective efforts are being made to understand the molecular details of host-pathogen interaction for possible translation into host-directed therapy. The present review focuses on 'host cell death modalities' of host-pathogen interaction, which play a crucial role in determining the outcome of TB disease progression. Several cell death modalities that occur in response to mycobacterial infection have been identified in human macrophages either as host defences for bacterial clearance or as pathogen strategies for multiplication and dissemination. These cell death modalities include apoptosis, necrosis, pyroptosis, necroptosis, pyronecrosis, NETosis, and autophagy. These processes are highly overlapping with several mycobacterial proteins participating in more than one cell death pathway. Until now, reviews in M. tb and host cell death have discussed either focusing on host evasion strategies, apoptosis, autophagy, and necrosis or describing all these forms with limited discussions of their role in host-pathogen interactions. Here, we present a comprehensive review of various mycobacterial factors modulating host cell death pathways and the cross-talk between them. Besides this, we have discussed the networking of host cell death pathways including the interference of host miRNA during M. tb infection with their respective targets. Through this review, we present the host targets that overlap across several cell death modalities and the technical limitations of methodology in cell death research. Given the compelling need to discover alternative drug target(s), this review identifies these overlapping cell death factors as potential targets for host-directed therapy.
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Affiliation(s)
- Krishnaveni Mohareer
- Molecular Pathogenesis Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India-500046
| | - Suman Asalla
- Molecular Pathogenesis Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India-500046
| | - Sharmistha Banerjee
- Molecular Pathogenesis Laboratory, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, India-500046.
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Phan TH, van Leeuwen LM, Kuijl C, Ummels R, van Stempvoort G, Rubio-Canalejas A, Piersma SR, Jiménez CR, van der Sar AM, Houben ENG, Bitter W. EspH is a hypervirulence factor for Mycobacterium marinum and essential for the secretion of the ESX-1 substrates EspE and EspF. PLoS Pathog 2018; 14:e1007247. [PMID: 30102741 PMCID: PMC6107294 DOI: 10.1371/journal.ppat.1007247] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 08/23/2018] [Accepted: 07/26/2018] [Indexed: 12/31/2022] Open
Abstract
The pathogen Mycobacterium tuberculosis employs a range of ESX-1 substrates to manipulate the host and build a successful infection. Although the importance of ESX-1 secretion in virulence is well established, the characterization of its individual components and the role of individual substrates is far from complete. Here, we describe the functional characterization of the Mycobacterium marinum accessory ESX-1 proteins EccA1, EspG1 and EspH, i.e. proteins that are neither substrates nor structural components. Proteomic analysis revealed that EspG1 is crucial for ESX-1 secretion, since all detectable ESX-1 substrates were absent from the cell surface and culture supernatant in an espG1 mutant. Deletion of eccA1 resulted in minor secretion defects, but interestingly, the severity of these secretion defects was dependent on the culture conditions. Finally, espH deletion showed a partial secretion defect; whereas several ESX-1 substrates were secreted in normal amounts, secretion of EsxA and EsxB was diminished and secretion of EspE and EspF was fully blocked. Interaction studies showed that EspH binds EspE and therefore could function as a specific chaperone for this substrate. Despite the observed differences in secretion, hemolytic activity was lost in all M. marinum mutants, implying that hemolytic activity is not strictly correlated with EsxA secretion. Surprisingly, while EspH is essential for successful infection of phagocytic host cells, deletion of espH resulted in a significantly increased virulence phenotype in zebrafish larvae, linked to poor granuloma formation and extracellular outgrowth. Together, these data show that different sets of ESX-1 substrates play different roles at various steps of the infection cycle of M. marinum. M. tuberculosis is a facultative intracellular pathogen that has an intimate relationship with host macrophages. Proteins secreted by the ESX-1 secretion system play an important role in this interaction, for instance by orchestrating the escape from the phagosome into the cytosol of the macrophage. However, the exact role of the ESX-1 substrates is unknown, due to their complicated interdependency for secretion. Here, we study the function of ESX-1 accessory proteins EccA1, EspG1 and EspH in ESX-1 secretion in Mycobacterium marium, the causative agent of fish tuberculosis. We found that these proteins affect the secretion of different substrate classes, which offers an approach to study the roles of these substrate groups. An espG1 deletion broadly aborts ESX-1 secretion and thus resulted in severe attenuation in a zebrafish model for tuberculosis, whereas EccA1 is only crucial under specific growth conditions. The most surprising results were obtained for EspH. This protein seems to function as a molecular chaperone for EspE and is as such involved in the secretion of a small subset of ESX-1 substrates. Disruption of espH showed a dual character: whereas this gene is essential for the successful infection of macrophages, deletion of espH resulted in significantly increased virulence in zebrafish larvae. These data convincingly show that different subsets of ESX-1 substrates play different roles at various steps in the mycobacterial infection cycle.
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Affiliation(s)
- Trang H. Phan
- Section Molecular Microbiology, Amsterdam Institute of Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Lisanne M. van Leeuwen
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Coen Kuijl
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Roy Ummels
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Gunny van Stempvoort
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Alba Rubio-Canalejas
- Section Molecular Microbiology, Amsterdam Institute of Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Sander R. Piersma
- Department of Medical Oncology, OncoProteomics Laboratory, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Connie R. Jiménez
- Department of Medical Oncology, OncoProteomics Laboratory, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Astrid M. van der Sar
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Edith N. G. Houben
- Section Molecular Microbiology, Amsterdam Institute of Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Wilbert Bitter
- Section Molecular Microbiology, Amsterdam Institute of Molecules, Medicines & Systems, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Amsterdam, the Netherlands
- * E-mail:
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Ganapathy US, Bai L, Wei L, Eckartt KA, Lett CM, Previti ML, Carrico IS, Seeliger JC. Compartment-Specific Labeling of Bacterial Periplasmic Proteins by Peroxidase-Mediated Biotinylation. ACS Infect Dis 2018; 4:918-925. [PMID: 29708735 DOI: 10.1021/acsinfecdis.8b00044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The study of the bacterial periplasm requires techniques with sufficient spatial resolution and sensitivity to resolve the components and processes within this subcellular compartment. Peroxidase-mediated biotinylation has enabled targeted labeling of proteins within subcellular compartments of mammalian cells. We investigated whether this methodology could be applied to the bacterial periplasm. In this study, we demonstrated that peroxidase-mediated biotinylation can be performed in mycobacteria and Escherichia coli. To eliminate detection artifacts from natively biotinylated mycobacterial proteins, we validated two alternative labeling substrates, tyramide azide and tyramide alkyne, which enable biotin-independent detection of labeled proteins. We also targeted peroxidase expression to the periplasm, resulting in compartment-specific labeling of periplasmic versus cytoplasmic proteins in mycobacteria. Finally, we showed that this method can be used to validate protein relocalization to the cytoplasm upon removal of a secretion signal. This novel application of peroxidase-mediated protein labeling will advance efforts to characterize the role of the periplasm in bacterial physiology and pathogenesis.
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Schatzman SS, Culotta VC. Chemical Warfare at the Microorganismal Level: A Closer Look at the Superoxide Dismutase Enzymes of Pathogens. ACS Infect Dis 2018. [PMID: 29517910 DOI: 10.1021/acsinfecdis.8b00026] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Superoxide anion radical is generated as a natural byproduct of aerobic metabolism but is also produced as part of the oxidative burst of the innate immune response design to kill pathogens. In living systems, superoxide is largely managed through superoxide dismutases (SODs), families of metalloenzymes that use Fe, Mn, Ni, or Cu cofactors to catalyze the disproportionation of superoxide to oxygen and hydrogen peroxide. Given the bursts of superoxide faced by microbial pathogens, it comes as no surprise that SOD enzymes play important roles in microbial survival and virulence. Interestingly, microbial SOD enzymes not only detoxify host superoxide but also may participate in signaling pathways that involve reactive oxygen species derived from the microbe itself, particularly in the case of eukaryotic pathogens. In this Review, we will discuss the chemistry of superoxide radicals and the role of diverse SOD metalloenzymes in bacterial, fungal, and protozoan pathogens. We will highlight the unique features of microbial SOD enzymes that have evolved to accommodate the harsh lifestyle at the host-pathogen interface. Lastly, we will discuss key non-SOD superoxide scavengers that specific pathogens employ for defense against host superoxide.
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Affiliation(s)
- Sabrina S. Schatzman
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Pubic Health, Johns Hopkins University, 615 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Valeria C. Culotta
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Pubic Health, Johns Hopkins University, 615 N. Wolfe Street, Baltimore, Maryland 21205, United States
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Global proteome and phosphoproteome dynamics indicate novel mechanisms of vitamin C induced dormancy in Mycobacterium smegmatis. J Proteomics 2018; 180:1-10. [DOI: 10.1016/j.jprot.2017.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 09/20/2017] [Accepted: 10/10/2017] [Indexed: 01/30/2023]
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Zulauf KE, Sullivan JT, Braunstein M. The SecA2 pathway of Mycobacterium tuberculosis exports effectors that work in concert to arrest phagosome and autophagosome maturation. PLoS Pathog 2018; 14:e1007011. [PMID: 29709019 PMCID: PMC5945054 DOI: 10.1371/journal.ppat.1007011] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/10/2018] [Accepted: 04/06/2018] [Indexed: 11/30/2022] Open
Abstract
To subvert host defenses, Mycobacterium tuberculosis (Mtb) avoids being delivered to degradative phagolysosomes in macrophages by arresting the normal host process of phagosome maturation. Phagosome maturation arrest by Mtb involves multiple effectors and much remains unknown about this important aspect of Mtb pathogenesis. The SecA2 dependent protein export system is required for phagosome maturation arrest and consequently growth of Mtb in macrophages. To better understand the role of the SecA2 pathway in phagosome maturation arrest, we identified two effectors exported by SecA2 that contribute to this process: the phosphatase SapM and the kinase PknG. Then, utilizing the secA2 mutant of Mtb as a platform to study effector functions, we identified specific steps in phagosome maturation inhibited by SapM and/or PknG. By identifying a histidine residue that is essential for SapM phosphatase activity, we confirmed for the first time that the phosphatase activity of SapM is required for its effects on phagosome maturation in macrophages. We further demonstrated that SecA2 export of SapM and PknG contributes to the ability of Mtb to replicate in macrophages. Finally, we extended our understanding of the SecA2 pathway, SapM, and PknG by revealing that their contribution goes beyond preventing Mtb delivery to mature phagolysosomes and includes inhibiting Mtb delivery to autophagolysosomes. Together, our results revealed SapM and PknG to be two effectors exported by the SecA2 pathway of Mtb with distinct as well as cumulative effects on phagosome and autophagosome maturation. Our results further reveal that Mtb must have additional mechanisms of limiting acidification of the phagosome, beyond inhibiting recruitment of the V-ATPase proton pump to the phagosome, and they indicate differences between effects of Mtb on phagosome and autophagosome maturation. Mycobacterium tuberculosis (Mtb) is the infectious agent of the disease tuberculosis. Inside the host, Mtb replicates primarily within the phagosome of macrophages. To replicate within macrophages, Mtb modifies the phagosome by inhibiting the normal host process of phagosomes maturing into acidified degradative phagolysosomes. In order to arrest this process of phagosome maturation, Mtb exports multiple effectors to the host-pathogen interface. Here we found that the specialized SecA2 protein export pathway of Mtb exports two such effectors: SapM and PknG. We discovered that SapM and PknG play non-redundant functions in phagosome maturation arrest by Mtb. We further demonstrated that SecA2 export of both SapM and PknG contributes to the ability of Mtb to replicate in macrophages. We also identified a role for the SecA2 pathway, SapM and PknG in arresting the host process of autophagosome maturation. Our research highlights how two effectors, SapM and PknG, work in concert but also have distinct roles in phagosome and autophagosome maturation arrest by Mtb.
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Affiliation(s)
- Katelyn E. Zulauf
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jonathan Tabb Sullivan
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Miriam Braunstein
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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Mahadik K, Prakhar P, Rajmani RS, Singh A, Balaji KN. c-Abl-TWIST1 Epigenetically Dysregulate Inflammatory Responses during Mycobacterial Infection by Co-Regulating Bone Morphogenesis Protein and miR27a. Front Immunol 2018; 9:85. [PMID: 29449840 PMCID: PMC5799226 DOI: 10.3389/fimmu.2018.00085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/11/2018] [Indexed: 12/12/2022] Open
Abstract
Mycobacteria propelled modulation of host responses is of considerable interest in the face of emerging drug resistance. Although it is known that Abl tyrosine kinases affect entry and persistence of mycobacteria, mechanisms that couple c-Abl to proximal signaling pathways during immunity are poorly understood. Loss-of-function of c-Abl through Imatinib, in a mouse model of tuberculosis or RNA interference, identified bone morphogenesis protein (BMP) signaling as its cellular target. We demonstrate that c-Abl promotes mycobacterial survival through epigenetic modification brought about by KAT5-TWIST1 at Bmp loci. c-Abl-BMP signaling deregulated iNOS, aggravating the inflammatory balance. Interestingly, BMP signaling was observed to have far-reaching effects on host immunity, as it attenuated TLR3 pathway by engaging miR27a. Significantly, these events were largely mediated via WhiB3 and DosR/S/T but not SecA signaling pathway of mycobacteria. Our findings suggest molecular mechanisms of host pathways hijacked by mycobacteria and expand our understanding of c-Abl inhibitors in potentiating innate immune responses.
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Affiliation(s)
- Kasturi Mahadik
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Praveen Prakhar
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - R S Rajmani
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
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Stutz MD, Clark MP, Doerflinger M, Pellegrini M. Mycobacterium tuberculosis: Rewiring host cell signaling to promote infection. J Leukoc Biol 2017; 103:259-268. [PMID: 29345343 PMCID: PMC6446910 DOI: 10.1002/jlb.4mr0717-277r] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/05/2017] [Accepted: 09/26/2017] [Indexed: 12/16/2022] Open
Abstract
The ability of Mycobacterium tuberculosis to cause disease hinges upon successfully thwarting the innate defenses of the macrophage host cell. The pathogen's trump card is its armory of virulence factors that throw normal host cell signaling into disarray. This process of subverting the macrophage begins upon entry into the cell, when M. tuberculosis actively inhibits the fusion of the bacilli‐laden phagosomes with lysosomes. The pathogen then modulates an array of host signal transduction pathways, which dampens the macrophage's host‐protective cytokine response, while simultaneously adapting host cell metabolism to stimulate lipid body accumulation. Mycobacterium tuberculosis also renovates the surface of its innate host cells by altering the expression of key molecules required for full activation of the adaptive immune response. Finally, the pathogen coordinates its exit from the host cell by shifting the balance from the host‐protective apoptotic cell death program toward a lytic form of host cell death. Thus, M. tuberculosis exploits its extensive repertoire of virulence factors in order to orchestrate the infection process to facilitate its growth, dissemination, and entry into latency. This review offers critical insights into the most recent advances in our knowledge of how M. tuberculosis manipulates host cell signaling. An appreciation of such interactions between the pathogen and host is critical for guiding novel therapies and understanding the factors that lead to the development of active disease in only a subset of exposed individuals.
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Affiliation(s)
- Michael D Stutz
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Michelle P Clark
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Marcel Doerflinger
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Marc Pellegrini
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
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Abstract
All bacteria utilize pathways to export proteins from the cytoplasm to the bacterial cell envelope or extracellular space. Many exported proteins function in essential physiological processes or in virulence. Consequently, the responsible protein export pathways are commonly essential and/or are important for pathogenesis. The general Sec protein export pathway is conserved and essential in all bacteria, and it is responsible for most protein export. The energy for Sec export is provided by the SecA ATPase. Mycobacteria and some Gram-positive bacteria have two SecA paralogs: SecA1 and SecA2. SecA1 is essential and works with the canonical Sec pathway to perform the bulk of protein export. The nonessential SecA2 exports a smaller subset of proteins and is required for the virulence of pathogens such as Mycobacterium tuberculosis. In this article, we review our current understanding of the mechanism of the SecA1 and SecA2 export pathways and discuss some of their better-studied exported substrates. We focus on proteins with established functions in M. tuberculosis pathogenesis and proteins that suggest potential roles for SecA1 and SecA2 in M. tuberculosis dormancy.
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47
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Perkowski EF, Zulauf KE, Weerakoon D, Hayden JD, Ioerger TR, Oreper D, Gomez SM, Sacchettini JC, Braunstein M. The EXIT Strategy: an Approach for Identifying Bacterial Proteins Exported during Host Infection. mBio 2017; 8:e00333-17. [PMID: 28442606 PMCID: PMC5405230 DOI: 10.1128/mbio.00333-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 04/04/2017] [Indexed: 12/12/2022] Open
Abstract
Exported proteins of bacterial pathogens function both in essential physiological processes and in virulence. Past efforts to identify exported proteins were limited by the use of bacteria growing under laboratory (in vitro) conditions. Thus, exported proteins that are exported only or preferentially in the context of infection may be overlooked. To solve this problem, we developed a genome-wide method, named EXIT (exported in vivotechnology), to identify proteins that are exported by bacteria during infection and applied it to Mycobacterium tuberculosis during murine infection. Our studies validate the power of EXIT to identify proteins exported during infection on an unprecedented scale (593 proteins) and to reveal in vivo induced exported proteins (i.e., proteins exported significantly more during in vivo infection than in vitro). Our EXIT data also provide an unmatched resource for mapping the topology of M. tuberculosis membrane proteins. As a new approach for identifying exported proteins, EXIT has potential applicability to other pathogens and experimental conditions.IMPORTANCE There is long-standing interest in identifying exported proteins of bacteria as they play critical roles in physiology and virulence and are commonly immunogenic antigens and targets of antibiotics. While significant effort has been made to identify the bacterial proteins that are exported beyond the cytoplasm to the membrane, cell wall, or host environment, current methods to identify exported proteins are limited by their use of bacteria growing under laboratory (in vitro) conditions. Because in vitro conditions do not mimic the complexity of the host environment, critical exported proteins that are preferentially exported in the context of infection may be overlooked. We developed a novel method to identify proteins that are exported by bacteria during host infection and applied it to identify Mycobacterium tuberculosis proteins exported in a mouse model of tuberculosis.
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Affiliation(s)
- E F Perkowski
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - K E Zulauf
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - D Weerakoon
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - J D Hayden
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - T R Ioerger
- Department of Computer Science and Engineering, Texas A&M University, College Station, Texas, USA
| | - D Oreper
- Joint Department of Biomedical Engineering at UNC-Chapel Hill and NC State University, Chapel Hill, North Carolina, USA
| | - S M Gomez
- Joint Department of Biomedical Engineering at UNC-Chapel Hill and NC State University, Chapel Hill, North Carolina, USA
| | - J C Sacchettini
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
| | - M Braunstein
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
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48
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Zhao L, Chen J, Sun J, Zhang D. Multimer recognition and secretion by the non-classical secretion pathway in Bacillus subtilis. Sci Rep 2017; 7:44023. [PMID: 28276482 PMCID: PMC5343618 DOI: 10.1038/srep44023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/02/2017] [Indexed: 01/02/2023] Open
Abstract
Non-classical protein secretion in bacteria is a common phenomenon. However, the selection principle for non-classical secretion pathways remains unclear. Here, our experimental data, to our knowledge, are the first to show that folded multimeric proteins can be recognized and excreted by a non-classical secretion pathway in Bacillus subtilis. We explored the secretion pattern of a typical cytoplasmic protein D-psicose 3-epimerase from Ruminococcus sp. 5_1_39BFAA (RDPE), and showed that its non-classical secretion is not simply due to cell lysis. Analysis of truncation variants revealed that the C- and N-terminus, and two hydrophobic domains, are required for structural stability and non-classical secretion of RDPE. Alanine scanning mutagenesis of the hydrophobic segments of RDPE revealed that hydrophobic residues mediated the equilibrium between its folded and unfolded forms. Reporter mCherry and GFP fusions with RDPE regions show that its secretion requires an intact tetrameric protein complex. Using cross-linked tetramers, we show that folded tetrameric RDPE can be secreted as a single unit. Finally, we provide evidence that the non-classical secretion pathway has a strong preference for multimeric substrates, which accumulate at the poles and septum region. Altogether, these data show that a multimer recognition mechanism is likely applicable across the non-classical secretion pathway.
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Affiliation(s)
- Liuqun Zhao
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Jingqi Chen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, P. R. China.,National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, P. R. China
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Abstract
Bacterial pathogens utilize a multitude of methods to invade mammalian hosts, damage tissue sites, and thwart the immune system from responding. One essential component of these strategies for many bacterial pathogens is the secretion of proteins across phospholipid membranes. Secreted proteins can play many roles in promoting bacterial virulence, from enhancing attachment to eukaryotic cells, to scavenging resources in an environmental niche, to directly intoxicating target cells and disrupting their functions. Many pathogens use dedicated protein secretion systems to secrete virulence factors from the cytosol of the bacteria into host cells or the host environment. In general, bacterial protein secretion apparatuses can be divided into classes, based on their structures, functions, and specificity. Some systems are conserved in all classes of bacteria and secrete a broad array of substrates, while others are only found in a small number of bacterial species and/or are specific to only one or a few proteins. In this chapter, we review the canonical features of several common bacterial protein secretion systems, as well as their roles in promoting the virulence of bacterial pathogens. Additionally, we address recent findings that indicate that the innate immune system of the host can detect and respond to the presence of protein secretion systems during mammalian infection.
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50
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Mazzantini D, Celandroni F, Salvetti S, Gueye SA, Lupetti A, Senesi S, Ghelardi E. FlhF Is Required for Swarming Motility and Full Pathogenicity of Bacillus cereus. Front Microbiol 2016; 7:1644. [PMID: 27807433 PMCID: PMC5069341 DOI: 10.3389/fmicb.2016.01644] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/03/2016] [Indexed: 11/13/2022] Open
Abstract
Besides sporulation, Bacillus cereus can undergo a differentiation process in which short swimmer cells become elongated and hyperflagellated swarmer cells that favor migration of the bacterial community on a surface. The functionally enigmatic flagellar protein FlhF, which is the third paralog of the signal recognition particle (SRP) GTPases Ffh and FtsY, is required for swarming in many bacteria. Previous data showed that FlhF is involved in the control of the number and positioning of flagella in B. cereus. In this study, in silico analysis of B. cereus FlhF revealed that this protein presents conserved domains that are typical of SRPs in many organisms and a peculiar N-terminal basic domain. By proteomic analysis, a significant effect of FlhF depletion on the amount of secreted proteins was found with some proteins increased (e.g., B component of the non-hemolytic enterotoxin, cereolysin O, enolase) and others reduced (e.g., flagellin, L2 component of hemolysin BL, bacillolysin, sphingomyelinase, PC-PLC, PI-PLC, cytotoxin K) in the extracellular proteome of a ΔflhF mutant. Deprivation of FlhF also resulted in significant attenuation in the pathogenicity of this strain in an experimental model of infection in Galleria mellonella larvae. Our work highlights the multifunctional role of FlhF in B. cereus, being this protein involved in bacterial flagellation, swarming, protein secretion, and pathogenicity.
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Affiliation(s)
- Diletta Mazzantini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy
| | - Francesco Celandroni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy
| | - Sara Salvetti
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy
| | - Sokhna A Gueye
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy
| | - Antonella Lupetti
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Pisa, Italy
| | - Sonia Senesi
- Department of Biology, University of Pisa Pisa, Italy
| | - Emilia Ghelardi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of PisaPisa, Italy; Research Center Nutraceuticals and Food for Health-Nutrafood, University of PisaPisa, Italy
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