1
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Jaisinghani N, Previti ML, Andrade J, Askenazi M, Ueberheide B, Seeliger JC. Cell wall proteomics in live Mycobacterium tuberculosis uncovers exposure of ESX substrates to the periplasm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534792. [PMID: 37034674 PMCID: PMC10081232 DOI: 10.1101/2023.03.29.534792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
The cell wall of mycobacteria plays a key role in interactions with the environment and its ability to act as a selective filter is crucial to bacterial survival. Proteins in the cell wall enable this function by mediating the import and export of diverse metabolites from ions to lipids to proteins. Accurately identifying cell wall proteins is an important step in assigning function, especially as many mycobacterial proteins lack functionally characterized homologues. Current methods for protein localization have inherent limitations that reduce accuracy. Here we showed that protein tagging by the engineered peroxidase APEX2 within live Mycobacterium tuberculosis enabled the accurate identification of the cytosolic and cell wall proteomes. Our data indicate that substrates of the virulence-associated Type VII ESX secretion system are exposed to the Mtb periplasm, providing insight into the currently unknown mechanism by which these proteins cross the mycobacterial cell envelope.
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Affiliation(s)
- Neetika Jaisinghani
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Mary L Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
| | | | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jessica C Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
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2
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Wang Y, Zhou Y, Shi C, Liu J, Lv G, Huang H, Li S, Duan L, Zheng X, Liu Y, Zhou H, Wang Y, Li Z, Ding K, Sun P, Huang Y, Lu X, Zhang ZM. A toxin-deformation dependent inhibition mechanism in the T7SS toxin-antitoxin system of Gram-positive bacteria. Nat Commun 2022; 13:6434. [PMID: 36307446 PMCID: PMC9616950 DOI: 10.1038/s41467-022-34034-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 10/11/2022] [Indexed: 12/25/2022] Open
Abstract
Toxin EsaD secreted by some S. aureus strains through the type VII secretion system (T7SS) specifically kills those strains lacking the antitoxin EsaG. Here we report the structures of EsaG, the nuclease domain of EsaD and their complex, which together reveal an inhibition mechanism that relies on significant conformational change of the toxin. To inhibit EsaD, EsaG breaks the nuclease domain of EsaD protein into two independent fragments that, in turn, sandwich EsaG. The originally well-folded ββα-metal finger connecting the two fragments is stretched to become a disordered loop, leading to disruption of the catalytic site of EsaD and loss of nuclease activity. This mechanism is distinct from that of the other Type II toxin-antitoxin systems, which utilize an intrinsically disordered region on the antitoxins to cover the active site of the toxins. This study paves the way for developing therapeutic approaches targeting this antagonism.
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Affiliation(s)
- Yongjin Wang
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Yang Zhou
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Chaowei Shi
- grid.59053.3a0000000121679639Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China
| | - Jiacong Liu
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Guohua Lv
- grid.258164.c0000 0004 1790 3548Division of Histology & Embryology, Medical College, Jinan University, Guangzhou, 510632 China
| | - Huisi Huang
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Shengrong Li
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Liping Duan
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Xinyi Zheng
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Yue Liu
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Haibo Zhou
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Yonghua Wang
- grid.79703.3a0000 0004 1764 3838School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640 China
| | - Zhengqiu Li
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Ke Ding
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Pinghua Sun
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Yun Huang
- grid.5386.8000000041936877XDepartment of Physiology & Biophysics, Weill Cornell Medicine, New York, NY 10065 USA
| | - Xiaoyun Lu
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China
| | - Zhi-Min Zhang
- grid.258164.c0000 0004 1790 3548International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, 510632 China ,Guangdong Youmei Institute of Intelligent Bio-manufacturing, Foshan, Guangdong 528200 China
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3
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Liang Z, Wu H, Bian C, Chen H, Shen Y, Gao X, Ma J, Yao H, Wang L, Wu Z. The antimicrobial systems of Streptococcus suis promote niche competition in pig tonsils. Virulence 2022; 13:781-793. [PMID: 35481413 PMCID: PMC9067509 DOI: 10.1080/21505594.2022.2069390] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Streptococcus suis can cause severe infections in pigs and humans. The tonsils of pigs are major niches for S. suis, and different serotypes of S. suis can be found in the same tonsil. Pig tonsil colonization by S. suis is believed to be an important source of infection for humans and pigs. However, how S. suis competes for a stable tonsil niche is unknown. Here, we found that S. suis strain WUSS351, isolated from a healthy pig tonsil, is virulent and multidrug-resistant. The ABC transporter system SstFEG, conferring resistance to bacitracin, was reported to confer a competitive survival advantage in vivo. In addition, strain WUSS351 has several antimicrobial systems, including a novel type VII secretion system (T7SS), lantibiotic bacteriocin, and lactococcin972-like bacteriocin Lcn351. Bacterial competition experiments demonstrated T7SS-mediated cell contact-dependent antagonism of S. suis. Antibacterial activity analysis and 16S rRNA gene sequencing of the culture-independent and culture-dependent pig tonsillar microbiome revealed that Lcn351 mainly targets S. suis, one of the core microbiomes in pig tonsils. Taken together, our results revealed the mechanism of the stable persistence of S. suis in the tonsil niche, which might have important implications for S. suis epidemiology, potentially influencing strain prevalence and disease progression.
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Affiliation(s)
- Zijing Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Huizhen Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Chen Bian
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Hao Chen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Yanling Shen
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Xueping Gao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Jiale Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Huochun Yao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Liping Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.,OIE Reference Lab for Swine Streptococcosis, Nanjing, China
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4
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Mycobacterium tuberculosis EspK Has Active but Distinct Roles in the Secretion of EsxA and EspB. J Bacteriol 2022; 204:e0006022. [PMID: 35315684 DOI: 10.1128/jb.00060-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Mycobacterium tuberculosis type-7 protein secretion system ESX-1 is a major driver of its virulence. While the functions of most ESX-1 components are characterized, many others remain poorly defined. In this study, we examined the role of EspK, an ESX-1-associated protein that is thought to be dispensable for ESX-1 activity in members of the Mycobacterium tuberculosis complex. We show that EspK is needed for the timely and optimal secretion of EsxA and absolutely essential for EspB secretion in M. tuberculosis Erdman. We demonstrate that only the EsxA secretion defect can be alleviated in EspK-deficient M. tuberculosis by culturing it in media containing detergents like Tween 80 or tyloxapol. Subcellular fractionation experiments reveal EspK is exported by M. tuberculosis in an ESX-1-independent manner and localized to its cell wall. We also show a conserved W-X-G motif in EspK is important for its interaction with EspB and enabling its secretion. The same motif, however, is not important for EspK localization in the cell wall. Finally, we show EspB in EspK-deficient M. tuberculosis tends to adopt higher-order oligomeric conformations, more so than EspB in wild-type M. tuberculosis. These results suggest EspK interacts with EspB and prevents it from assembling prematurely into macromolecular complexes that are presumably too large to pass through the membrane-spanning ESX-1 translocon assembly. Collectively, our findings indicate M. tuberculosis EspK has a far more active role in ESX-1-mediated secretion than was previously appreciated and underscores the complex nature of this secretion apparatus. IMPORTANCE Mycobacterium tuberculosis uses its ESX-1 system to secrete EsxA and EspB into a host to cause disease. We show that EspK, a protein whose role in the ESX-1 machinery was thought to be nonessential, is needed by M. tuberculosis for optimal EsxA and EspB secretion. Culturing EspK-deficient M. tuberculosis with detergents alleviates EsxA but not EspB secretion defects. We also show that EspK, which is exported by M. tuberculosis in an ESX-1-independent manner to the cell wall, interacts with and prevents EspB from assembling into large structures inside the M. tuberculosis cell that are nonsecretable. Collectively, our observations demonstrate EspK is an active component of the ESX-1 secretion machinery of the tubercle bacillus.
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5
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Multiple genetic paths including massive gene amplification allow Mycobacterium tuberculosis to overcome loss of ESX-3 secretion system substrates. Proc Natl Acad Sci U S A 2022; 119:2112608119. [PMID: 35193958 PMCID: PMC8872769 DOI: 10.1073/pnas.2112608119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2021] [Indexed: 01/18/2023] Open
Abstract
The Mycobacterium tuberculosis (Mtb) ESX-3 type VII secretion system plays a critical role in iron acquisition. Infection of mice with highly attenuated Mtb deletion mutants lacking esxG or esxH, genes encoding key ESX-3 substrates, unexpectedly yielded suppressor mutants with restored capacity to grow in vivo and in vitro in the absence of iron supplementation. Whole-genome sequencing identified two mechanisms of suppression, the disruption of a transcriptional repressor that regulates expression of an ESX-3 paralogous region encoding EsxR and EsxS, and a massive 38- to 60-fold gene amplification of this same region. These data are significant because they reveal a previously unrecognized iron acquisition regulon and inform mechanisms of Mtb chromosome evolution. Mycobacterium tuberculosis (Mtb) possesses five type VII secretion systems (T7SS), virulence determinants that include the secretion apparatus and associated secretion substrates. Mtb strains deleted for the genes encoding substrates of the ESX-3 T7SS, esxG or esxH, require iron supplementation for in vitro growth and are highly attenuated in vivo. In a subset of infected mice, suppressor mutants of esxG or esxH deletions were isolated, which enabled growth to high titers or restored virulence. Suppression was conferred by mechanisms that cause overexpression of an ESX-3 paralogous region that lacks genes for the secretion apparatus but encodes EsxR and EsxS, apparent ESX-3 orphan substrates that functionally compensate for the lack of EsxG or EsxH. The mechanisms include the disruption of a transcriptional repressor and a massive 38- to 60-fold gene amplification. These data identify an iron acquisition regulon, provide insight into T7SS, and reveal a mechanism of Mtb chromosome evolution involving “accordion-type” amplification.
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6
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An Introduction to Bacterial Biofilms and Their Proteases, and Their Roles in Host Infection and Immune Evasion. Biomolecules 2022; 12:biom12020306. [PMID: 35204806 PMCID: PMC8869686 DOI: 10.3390/biom12020306] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/03/2022] [Accepted: 02/10/2022] [Indexed: 12/15/2022] Open
Abstract
Bacterial biofilms represent multicellular communities embedded in a matrix of extracellular polymeric substances, conveying increased resistance against environmental stress factors but also antibiotics. They are shaped by secreted enzymes such as proteases, which can aid pathogenicity by degrading host proteins of the connective tissue or the immune system. Importantly, both secreted proteases and the capability of biofilm formation are considered key virulence factors. In this review, we focus on the basic aspects of proteolysis and protein secretion, and highlight various secreted bacterial proteases involved in biofilm establishment and dispersal, and how they aid bacteria in immune evasion by degrading immunoglobulins and components of the complement system. Thus, secreted proteases represent not only prominent antimicrobial targets but also enzymes that can be used for dedicated applications in biotechnology and biomedicine, including their use as laundry detergents, in mass spectrometry for the glycoprofiling of antibodies, and the desensitization of donor organs intended for positive crossmatch patients.
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7
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Wu Q, Wang B, Shen X, Shen D, Wang B, Guo Q, Li T, Shao X, Qian G. Unlocking the bacterial contact-dependent antibacterial activity to engineer a biocontrol alliance of two species from natural incompatibility to artificial compatibility. STRESS BIOLOGY 2021; 1:19. [PMID: 37676524 PMCID: PMC10441968 DOI: 10.1007/s44154-021-00018-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/22/2021] [Indexed: 09/08/2023]
Abstract
Plant growth-promoting rhizobacteria (PGPR) contain various biocontrol bacteria with broad-spectrum antimicrobial activity, and their single species has been extensively applied to control crop diseases. The development of complex biocontrol community by mixing two or more PGPR members together is a promising strategy to enlarge the efficacy and scope of biocontrol. However, an effective method to assess the natural compatibility of PGPR members has not yet been established to date. Here, we developed such a tool by using the bacterial contact-dependent antibacterial activity (CDAA) as a probe. We showed that the CDAA events are common in two-species interactions in the four selected representative PGPRs, represented by the incompatible interaction of Lysobacter enzymogenes strain OH11 (OH11) and Lysobacter antibioticus strain OH13 (OH13). We further showed that the CDAA between OH11 and OH13 is jointly controlled by a contact-dependent killing device, called the type IV secretion system (T4SS). By deleting the respective T4SS synthesis genes, the T4SS in both strains was co-inactivated and this step unlocked their natural CDAA, resulting in an engineered, compatible mutant alliance that co-displayed antibacterial and antifungal activity. Therefore, this study reveals that releasing bacterial CDAA is effective to rationally engineer the biocontrol community.
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Affiliation(s)
- Qianhua Wu
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Bozhen Wang
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Xi Shen
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Danyu Shen
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Bingxin Wang
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Qinggang Guo
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences, Integrated Pest Management Center of Hebei Province, Key Laboratory of IPM on Crops in Northern Region of North China, Ministry of Agriculture and Rural Affairs of China, Baoding, 071000, People's Republic of China
| | - Tao Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, People's Republic of China
| | - Xiaolong Shao
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China
| | - Guoliang Qian
- College of Plant Protection, Laboratory of Plant Immunity, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, No.1 Weigang, Nanjing, Jiangsu, 210095, People's Republic of China.
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8
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Lagune M, Petit C, Sotomayor FV, Johansen MD, Beckham KSH, Ritter C, Girard-Misguich F, Wilmanns M, Kremer L, Maurer FP, Herrmann JL. Conserved and specialized functions of Type VII secretion systems in non-tuberculous mycobacteria. MICROBIOLOGY-SGM 2021; 167. [PMID: 34224347 DOI: 10.1099/mic.0.001054] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Non-tuberculous mycobacteria (NTM) are a large group of micro-organisms comprising more than 200 individual species. Most NTM are saprophytic organisms and are found mainly in terrestrial and aquatic environments. In recent years, NTM have been increasingly associated with infections in both immunocompetent and immunocompromised individuals, prompting significant efforts to understand the diverse pathogenic and signalling traits of these emerging pathogens. Since the discovery of Type VII secretion systems (T7SS), there have been significant developments regarding the role of these complex systems in mycobacteria. These specialised systems, also known as Early Antigenic Secretion (ESX) systems, are employed to secrete proteins across the inner membrane. They also play an essential role in virulence, nutrient uptake and conjugation. Our understanding of T7SS in mycobacteria has significantly benefited over the last few years, from the resolution of ESX-3 structure in Mycobacterium smegmatis, to ESX-5 structures in Mycobacterium xenopi and Mycobacterium tuberculosis. In addition, ESX-4, considered until recently as a non-functional system in both pathogenic and non-pathogenic mycobacteria, has been proposed to play an important role in the virulence of Mycobacterium abscessus; an increasingly recognized opportunistic NTM causing severe lung diseases. These major findings have led to important new insights into the functional mechanisms of these biological systems, their implication in virulence, nutrient acquisitions and cell wall shaping, and will be discussed in this review.
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Affiliation(s)
- Marion Lagune
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, 78180, Montigny-Le-Bretonneux, France
| | - Cecile Petit
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany
| | - Flor Vásquez Sotomayor
- National and WHO Supranational Reference Center for Mycobacteria, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Matt D Johansen
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293, Montpellier, France.,Present address: Centre for Inflammation, Centenary Institute and University of Technology Sydney, Faculty of Science, Sydney, NSW, Australia
| | - Kathrine S H Beckham
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany
| | - Christina Ritter
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany
| | - Fabienne Girard-Misguich
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, 78180, Montigny-Le-Bretonneux, France
| | - Matthias Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Notkestraße 85, 22607 Hamburg, Germany.,University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20251 Hamburg, Germany
| | - Laurent Kremer
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293, Montpellier, France.,INSERM, IRIM, 34293 Montpellier, France
| | - Florian P Maurer
- National and WHO Supranational Reference Center for Mycobacteria, Research Center Borstel, Leibniz Lung Center, Borstel, Germany.,Institute of Medical Microbiology, Virology and Hospital Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jean-Louis Herrmann
- Université Paris-Saclay, UVSQ, Inserm, Infection et inflammation, 78180, Montigny-Le-Bretonneux, France.,APHP, GHU Paris-Saclay, Hôpital Raymond Poincaré, Service de Microbiologie, Garches, France
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9
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Computational prediction of secreted proteins in gram-negative bacteria. Comput Struct Biotechnol J 2021; 19:1806-1828. [PMID: 33897982 PMCID: PMC8047123 DOI: 10.1016/j.csbj.2021.03.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/18/2021] [Accepted: 03/18/2021] [Indexed: 12/29/2022] Open
Abstract
Gram-negative bacteria harness multiple protein secretion systems and secrete a large proportion of the proteome. Proteins can be exported to periplasmic space, integrated into membrane, transported into extracellular milieu, or translocated into cytoplasm of contacting cells. It is important for accurate, genome-wide annotation of the secreted proteins and their secretion pathways. In this review, we systematically classified the secreted proteins according to the types of secretion systems in Gram-negative bacteria, summarized the known features of these proteins, and reviewed the algorithms and tools for their prediction.
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10
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Drever K, Lim ZL, Zriba S, Chen JM. Protein Synthesis and Degradation Inhibitors Potently Block Mycobacterium tuberculosis type-7 Secretion System ESX-1 Activity. ACS Infect Dis 2021; 7:273-280. [PMID: 33534536 DOI: 10.1021/acsinfecdis.0c00741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mycobacterium tuberculosis (M. tb) uses its type-7 secretion system ESX-1 to translocate key virulence effector proteins. Taking a chemical genetics approach, we demonstrate for the first time the importance of mycobacterial proteostasis to ESX-1. We show that individual treatment with inhibitors of protein synthesis (chloramphenicol and kanamycin) and protein degradation (lassomycin and bortezomib), at concentrations that only reduce M. tb growth by 50% and less, specifically block ESX-1 secretion activity in the tubercle bacillus. In contrast, the mycobacterial cell-wall synthesis inhibitor isoniazid, even at a concentration that reduces M. tb growth by 90% has no effect on ESX-1 secretion activity. We also show that chloramphenicol but not isoniazid at subinhibitory concentrations specifically attenuates ESX-1-mediated M. tb virulence in macrophages. Taken together, the results of our study identify a novel vulnerability in the ESX-1 system and offer new avenues of anti-TB drug research to neutralize this critical virulence-mediating protein secretion apparatus.
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Affiliation(s)
- Kylee Drever
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada
| | - Ze Long Lim
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
| | - Slim Zriba
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
- Vaccinology and Immunotherapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan S7N 2Z4, Canada
| | - Jeffrey M. Chen
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan S7N 5E3, Canada
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada
- Vaccinology and Immunotherapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan S7N 2Z4, Canada
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11
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Taylor JC, Gao X, Xu J, Holder M, Petrosino J, Kumar R, Liu W, Höök M, Mackenzie C, Hillhouse A, Brashear W, Nunez MP, Xu Y. A type VII secretion system of Streptococcus gallolyticus subsp. gallolyticus contributes to gut colonization and the development of colon tumors. PLoS Pathog 2021; 17:e1009182. [PMID: 33406160 PMCID: PMC7815207 DOI: 10.1371/journal.ppat.1009182] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/19/2021] [Accepted: 11/23/2020] [Indexed: 02/06/2023] Open
Abstract
Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon tumors. However, the molecular determinants involved in Sgg pathogenicity in the gut are unknown. Bacterial type VII secretion systems (T7SS) mediate pathogen interactions with their host and are important for virulence in pathogenic mycobacteria and Staphylococcus aureus. Through genome analysis, we identified a locus in Sgg strain TX20005 that encodes a putative type VII secretion system (designated as SggT7SST05). We showed that core genes within the SggT7SST05 locus are expressed in vitro and in the colon of mice. Western blot analysis showed that SggEsxA, a protein predicted to be a T7SS secretion substrate, is detected in the bacterial culture supernatant, indicating that this SggT7SST05 is functional. Deletion of SggT7SST05 (TX20005Δesx) resulted in impaired bacterial adherence to HT29 cells and abolished the ability of Sgg to stimulate HT29 cell proliferation. Analysis of bacterial culture supernatants suggest that SggT7SST05-secreted factors are responsible for the pro-proliferative activity of Sgg, whereas Sgg adherence to host cells requires both SggT7SST05-secreted and bacterial surface-associated factors. In a murine gut colonization model, TX20005Δesx showed significantly reduced colonization compared to the parent strain. Furthermore, in a mouse model of CRC, mice exposed to TX20005 had a significantly higher tumor burden compared to saline-treated mice, whereas those exposed to TX20005Δesx did not. Examination of the Sgg load in the colon in the CRC model suggests that SggT7SST05-mediated activities are directly involved in the promotion of colon tumors. Taken together, these results reveal SggT7SST05 as a previously unrecognized pathogenicity determinant for Sgg colonization of the colon and promotion of colon tumors. Colorectal cancer (CRC) is a leading cause of cancer-related death. The development of CRC can be strongly influenced by specific gut microbes. Understanding how gut microbes modulate CRC is critical to developing novel strategies to improve clinical diagnosis and treatment of this disease. S. gallolyticus subsp. gallolyticus (Sgg) has a strong clinical association with CRC and actively promotes the development of colon tumors. However, the specific Sgg molecules that mediate its pro-tumor activity are unknown. Here we report the first characterization of a type VII secretion system (T7SS) in Sgg, designated as SggT7SST05. We further demonstrate that SggT7SST05-mediated activities are important for Sgg to colonize the colon and to promote the development of colon tumors. These findings reveal SggT7SST05 as a novel pathogenicity determinant of Sgg and provide a critical breakthrough in our efforts to understand how Sgg influences the development of CRC. Future investigations of the biological activities of specific effectors of SggT7SST05 will likely lead to the discovery of Sgg molecules that can be used as diagnostic markers and intervention targets aimed at mitigating the harmful effect of Sgg.
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Affiliation(s)
- John Culver Taylor
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Xinsheng Gao
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Juan Xu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Michael Holder
- Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, Texas, United States of America
| | - Joseph Petrosino
- Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ritesh Kumar
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Wen Liu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Chris Mackenzie
- Department of Microbiology and Molecular Genetics, McGovern Medical School, UT Health, Houston, Texas, United States of America
| | - Andrew Hillhouse
- Texas A&M Institute for Genome Sciences and Society, Texas A&M, Texas, United States of America
| | - Wesley Brashear
- Texas A&M Institute for Genome Sciences and Society, Texas A&M, Texas, United States of America
| | - Maria Patricia Nunez
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Yi Xu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
- Department of Microbiology and Molecular Genetics, McGovern Medical School, UT Health, Houston, Texas, United States of America
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas, United States of America
- * E-mail:
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12
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Modeling Tubercular ESX-1 Secretion Using Mycobacterium marinum. Microbiol Mol Biol Rev 2020; 84:84/4/e00082-19. [DOI: 10.1128/mmbr.00082-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Pathogenic mycobacteria cause chronic and acute diseases ranging from human tuberculosis (TB) to nontubercular infections.
Mycobacterium tuberculosis
causes both acute and chronic human tuberculosis. Environmentally acquired nontubercular mycobacteria (NTM) cause chronic disease in humans and animals. Not surprisingly, NTM and
M. tuberculosis
often use shared molecular mechanisms to survive within the host. The ESX-1 system is a specialized secretion system that is essential for virulence and is functionally conserved between
M. tuberculosis
and
Mycobacterium marinum
.
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13
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Poweleit N, Czudnochowski N, Nakagawa R, Trinidad DD, Murphy KC, Sassetti CM, Rosenberg OS. The structure of the endogenous ESX-3 secretion system. eLife 2019; 8:52983. [PMID: 31886769 PMCID: PMC6986878 DOI: 10.7554/elife.52983] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/30/2019] [Indexed: 12/15/2022] Open
Abstract
The ESX (or Type VII) secretion systems are protein export systems in mycobacteria and many Gram-positive bacteria that mediate a broad range of functions including virulence, conjugation, and metabolic regulation. These systems translocate folded dimers of WXG100-superfamily protein substrates across the cytoplasmic membrane. We report the cryo-electron microscopy structure of an ESX-3 system, purified using an epitope tag inserted with recombineering into the chromosome of the model organism Mycobacterium smegmatis. The structure reveals a stacked architecture that extends above and below the inner membrane of the bacterium. The ESX-3 protomer complex is assembled from a single copy of the EccB3, EccC3, and EccE3 and two copies of the EccD3 protein. In the structure, the protomers form a stable dimer that is consistent with assembly into a larger oligomer. The ESX-3 structure provides a framework for further study of these important bacterial transporters.
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Affiliation(s)
- Nicole Poweleit
- Department of Medicine, Division of Infectious Diseases, University of California, San Francisco, San Francisco, United States.,Chan-Zuckerberg Biohub, University of California, San Francisco, San Francisco, United States
| | - Nadine Czudnochowski
- Department of Medicine, Division of Infectious Diseases, University of California, San Francisco, San Francisco, United States.,Chan-Zuckerberg Biohub, University of California, San Francisco, San Francisco, United States
| | - Rachel Nakagawa
- Department of Medicine, Division of Infectious Diseases, University of California, San Francisco, San Francisco, United States
| | - Donovan D Trinidad
- Department of Medicine, Division of Infectious Diseases, University of California, San Francisco, San Francisco, United States.,Chan-Zuckerberg Biohub, University of California, San Francisco, San Francisco, United States
| | - Kenan C Murphy
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, United States
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, United States
| | - Oren S Rosenberg
- Department of Medicine, Division of Infectious Diseases, University of California, San Francisco, San Francisco, United States.,Chan-Zuckerberg Biohub, University of California, San Francisco, San Francisco, United States
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14
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Pan Y, An H, Fu T, Zhao S, Zhang C, Xiao G, Zhang J, Zhao X, Hu G. Characterization of Streptococcus pluranimalium from a cattle with mastitis by whole genome sequencing and functional validation. BMC Microbiol 2018; 18:182. [PMID: 30419812 PMCID: PMC6233522 DOI: 10.1186/s12866-018-1327-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 10/29/2018] [Indexed: 11/17/2022] Open
Abstract
Background Streptococcus pluranimalium is a new member of the Streptococcus genus isolated from multiple different animal hosts. It has been identified as a pathogen associated with subclinical mastitis, valvular endocarditis and septicaemia in animals. Moreover, this bacterium has emerged as a new pathogen for human infective endocarditis and brain abscess. However, the patho-biological properties of S. pluranimalium remain virtually unknown. The aim of this study was to determine the complete genome sequence of S. pluranimalium strain TH11417 isolated from a cattle with mastitis, and to characterize its antimicrobial resistance, virulence, and carbon catabolism. Results The genome of S. pluranimalium TH11417, determined by single-molecule real-time (SMRT) sequencing, consists of 2,065,522 base pair (bp) with a G + C content of 38.65%, 2,007 predicted coding sequence (CDS), 58 transfer RNA (tRNA) genes and five ribosome RNA (rRNA) operons. It contains a novel ISSpl1 element (a memeber of the IS3 family) and a Ф11417.1 prophage that carries the mef(A), msr(D) and lnu(C) genes. Consistently, our antimicrobial susceptibility test confirmed that S. pluranimalium TH11417 was resistant to erythromycin and lincomycin. However, this strain did not show virulence in murine pneumonia (intranasal inoculation, 107 colony forming unit – CFU) and sepsis (intraperitoneal inoculation, 107 CFU) models. Additionally, this strain is able to grow with glucose, lactose or galactose as the sole carbon source, and possesses a lactose-specific phosphoenolpyruvate-dependent phosphotransferase system (PTS). Conclusions We reported the first whole genome sequence of S. pluranimalium isolated from a cattle with mastitis. It harbors a prophage carrying the mef(A), msr(D) and lnu(C) genes, and is avirulent in the murine infection model.
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Affiliation(s)
- Yushan Pan
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China. .,Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China.
| | - Haoran An
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China.,Tsinghua-Peking Joint Center for Life Science, School of Medicine, Tsinghua University, Beijing, China
| | - Tong Fu
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Shiyu Zhao
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Chengwang Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Genhui Xiao
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Jingren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
| | - Xinfang Zhao
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Gongzheng Hu
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.
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15
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Hara H, Seregin SS, Yang D, Fukase K, Chamaillard M, Alnemri ES, Inohara N, Chen GY, Núñez G. The NLRP6 Inflammasome Recognizes Lipoteichoic Acid and Regulates Gram-Positive Pathogen Infection. Cell 2018; 175:1651-1664.e14. [PMID: 30392956 DOI: 10.1016/j.cell.2018.09.047] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 03/26/2018] [Accepted: 09/21/2018] [Indexed: 02/08/2023]
Abstract
The activator and composition of the NLRP6 inflammasome remain poorly understood. We find that lipoteichoic acid (LTA), a molecule produced by Gram-positive bacteria, binds and activates NLRP6. In response to cytosolic LTA or infection with Listeria monocytogenes, NLRP6 recruited caspase-11 and caspase-1 via the adaptor ASC. NLRP6 activation by LTA induced processing of caspase-11, which promoted caspase-1 activation and interleukin-1β (IL-1β)/IL-18 maturation in macrophages. Nlrp6-/- and Casp11-/- mice were less susceptible to L. monocytogenes infection, which was associated with reduced pathogen loads and impaired IL-18 production. Administration of IL-18 to Nlrp6-/- or Casp11-/- mice restored the susceptibility of mutant mice to L. monocytogenes infection. These results reveal a previously unrecognized innate immunity pathway triggered by cytosolic LTA that is sensed by NLRP6 and exacerbates systemic Gram-positive pathogen infection via the production of IL-18.
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Affiliation(s)
- Hideki Hara
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Sergey S Seregin
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Dahai Yang
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Koichi Fukase
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Mathias Chamaillard
- CIIL-Centre d'Infection et d'Immunité de Lille, Université de Lille, CNRS, Inserm, CHRU Lille, Institut Pasteur de Lille, U1019-UMR 8204, F-59000, Lille, France
| | - Emad S Alnemri
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Naohiro Inohara
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Grace Y Chen
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Gabriel Núñez
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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16
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Lebre PH, Aliyu H, De Maayer P, Cowan DA. In silico characterization of the global Geobacillus and Parageobacillus secretome. Microb Cell Fact 2018; 17:156. [PMID: 30285747 PMCID: PMC6171300 DOI: 10.1186/s12934-018-1005-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 09/26/2018] [Indexed: 11/17/2022] Open
Abstract
Background Geobacillus and Parageobacillus are two ecologically diverse thermophilic genera within the phylum Firmicutes. These taxa have long been of biotechnological interest due to their ability to secrete thermostable enzymes and other biomolecules that have direct applications in various industrial and clinical fields. Despite the commercial and industrial interest in these microorganisms, the full scope of the secreted protein, i.e. the secretome, of Geobacillus and Parageobacillus species remains largely unexplored, with most studies focusing on single enzymes. A genome-wide exploration of the global secretome can provide a platform for understanding the extracellular functional “protein cloud” and the roles that secreted proteins play in the survival and adaptation of these biotechnologically relevant organisms. Results In the present study, the global secretion profile of 64 Geobacillus and Parageobacillus strains, comprising 772 distinct proteins, was predicted using comparative genomic approaches. Thirty-one of these proteins are shared across all strains used in this study and function in cell-wall/membrane biogenesis as well as transport and metabolism of carbohydrates, amino acids and inorganic ions. An analysis of the clustering patterns of the secretomes of the 64 strains according to shared functional orthology revealed a correlation between the secreted profiles of different strains and their phylogeny, with Geobacillus and Parageobacillus species forming two distinct functional clades. Conclusions The in silico characterization of the global secretome revealed a metabolically diverse set of secreted proteins, which include proteases, glycoside hydrolases, nutrient binding proteins and toxins. Electronic supplementary material The online version of this article (10.1186/s12934-018-1005-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pedro H Lebre
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Habibu Aliyu
- Technical Biology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Pieter De Maayer
- School of Molecular and Cell Biology, University of Witwatersrand, Johannesburg, South Africa
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.
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17
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Beall CJ, Mokrzan EM, Griffen AL, Leys EJ. Cultivation of Peptidiphaga gingivicola from subgingival plaque: The first representative of a novel genus of Actinomycetaceae. Mol Oral Microbiol 2017; 33:105-110. [PMID: 29105370 DOI: 10.1111/omi.12205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2017] [Indexed: 12/20/2022]
Abstract
A novel bacterium was isolated from the subgingival plaque of a patient with periodontal disease. Bacterial strain BA112T is a facultative Gram-positive coccus. It metabolizes alanine, arginine, glycine, histidine, leucine, proline, serine and tyrosine, but does not appear to use carbohydrates. Urease, esculin, indole, catalase and nitrate reduction tests were all negative. Major cellular fatty acids were C18:0 , C12:0 , C16:0 , C18:1 w9c and C20:0 . The genome was sequenced and is 2.4 Mbp in length and has 64% GC content. Based on phylogenetics of the 16S rRNA sequence and concatenated alignments of 37 conserved proteins, BA112T belongs to the family Actinomycetaceae but is located on a branch of the tree without currently named members. Based on our phenotypic and phylogenetic studies, we propose that BA112T is the first known representative of a new genus, for which the name Peptidiphaga gingivicola gen. nov., sp. nov. is proposed. The type strain is BA112T .
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Affiliation(s)
- C J Beall
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, OH, USA
| | - E M Mokrzan
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, OH, USA.,Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - A L Griffen
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, OH, USA
| | - E J Leys
- Division of Biosciences, The Ohio State University College of Dentistry, Columbus, OH, USA
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18
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Cruciani M, Etna MP, Camilli R, Giacomini E, Percario ZA, Severa M, Sandini S, Rizzo F, Brandi V, Balsamo G, Polticelli F, Affabris E, Pantosti A, Bagnoli F, Coccia EM. Staphylococcus aureus Esx Factors Control Human Dendritic Cell Functions Conditioning Th1/Th17 Response. Front Cell Infect Microbiol 2017; 7:330. [PMID: 28785545 PMCID: PMC5519619 DOI: 10.3389/fcimb.2017.00330] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/05/2017] [Indexed: 02/01/2023] Open
Abstract
The opportunistic pathogen Staphylococcus aureus (S. aureus) is a major cause of nosocomial- and community-acquired infections. In addition, many antibiotic-resistant strains are emerging worldwide, thus, there is an urgent unmet need to pinpoint novel therapeutic and prophylactic strategies. In the present study, we characterized the impact of infection with the pandemic methicillin-resistant USA300 S. aureus strain on human primary dendritic cells (DC), key initiators and regulators of immune responses. In particular, among staphylococcal virulence factors, the function of EsxA and EsxB, two small acidic dimeric proteins secreted by the type VII-like secretion system Ess (ESAT-6-like secretion system), was investigated in human DC setting. A comparative analysis of bacterial entry, replication rate as well as DC maturation, apoptosis, signaling pathway activation and cytokine production was performed by using wild type (wt) USA300 and three isogenic mutants carrying the deletion of esxA (ΔesxA), esxB (ΔesxB), or both genes (ΔesxAB). The S. aureus mutant lacking only the EsxA protein (ΔesxA) stimulated a stronger pro-apoptotic phenotype in infected DC as compared to wt USA300, ΔesxAB, and ΔesxB strains. When the mutant carrying the esxB deletion (ΔesxB) was analyzed, a higher production of both regulatory and pro-inflammatory mediators was found in the infected DC with respect to those challenged with the wt counterpart and the other esx mutants. In accordance with these data, supernatant derived from ΔesxB-infected DC promoted a stronger release of both IFN-γ and IL-17 from CD4+ T cells as compared with those conditioned with supernatants derived from wild type USA300-, ΔesxAB-, and ΔesxA-infected cultures. Although, the interaction of S. aureus with human DC is not yet fully understood, our data suggest that both cytokine production and apoptotic process are modulated by Esx factors, thus indicating a possible role of these proteins in the modulation of DC-mediated immunity to S. aureus.
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Affiliation(s)
- Melania Cruciani
- Department of Science, University Roma TreRome, Italy.,Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | - Marilena P Etna
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | - Romina Camilli
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | - Elena Giacomini
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | | | - Martina Severa
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | - Silvia Sandini
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | - Fabiana Rizzo
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | | | | | - Fabio Polticelli
- Department of Science, University Roma TreRome, Italy.,National Institute of Nuclear Physics, Roma Tre UniversityRome, Italy
| | | | - Annalisa Pantosti
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
| | | | - Eliana M Coccia
- Department of Infectious Diseases, Istituto Superiore di SanitàRome, Italy
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19
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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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20
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Ates LS, Brosch R. Discovery of the type VII ESX-1 secretion needle? Mol Microbiol 2016; 103:7-12. [PMID: 27859892 DOI: 10.1111/mmi.13579] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2016] [Indexed: 01/03/2023]
Abstract
Mycobacterium tuberculosis, the etiological agent of human tuberculosis, harbours five ESAT-6/type VII secretion (ESX/T7S) systems. The first esx gene clusters were identified during the genome-sequencing project of M. tuberculosis H37Rv. Follow-up studies revealed additional genes playing important roles in ESX/T7S systems. Among the latter genes, one can find those that encode Pro-Glu (PE) and Pro-Pro-Glu (PPE) proteins as well as a gene cluster that is encoded >260 kb upstream of the esx-1 locus and encodes ESX-1 secretion-associated proteins EspA (Rv3616c), EspC (Rv3615c) and EspD (Rv3614c). The espACD cluster has been suggested to have an important function in ESX-1 secretion since EspA-EspC and EsxA-EsxB are mutually co-dependent on each other for secretion. However, the molecular mechanism of this co-dependence and interaction between the substrates remained unknown. In this issue of Molecular Microbiology, Lou and colleagues show that EspC forms high-molecular weight polymerization complexes that resemble selected components of type II, III and/or IV secretion systems of Gram-negative bacteria. Indeed, EspC-multimeric complexes form filamentous structures that could well represent a secretion needle of ESX-1 type VII secretion systems. This exciting observation opens new avenues for research to discover and characterize ESX/T7S components and elucidates the co-dependence of EsxA/B secretion with EspA/C.
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Affiliation(s)
- Louis S Ates
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, 75724 Paris Cedex 15, France
| | - Roland Brosch
- Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, 75724 Paris Cedex 15, France
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21
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Pinheiro J, Reis O, Vieira A, Moura IM, Zanolli Moreno L, Carvalho F, Pucciarelli MG, García-Del Portillo F, Sousa S, Cabanes D. Listeria monocytogenes encodes a functional ESX-1 secretion system whose expression is detrimental to in vivo infection. Virulence 2016; 8:993-1004. [PMID: 27723420 DOI: 10.1080/21505594.2016.1244589] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Bacterial pathogenicity deeply depends on the ability to secrete virulence factors that bind specific targets on host cells and manipulate host responses. The Gram-positive bacterium Listeria monocytogenes is a human foodborne pathogen that remains a serious public health concern. To transport proteins across its cell envelope, this facultative intracellular pathogen engages a set of specialized secretion systems. Here we show that L. monocytogenes EGDe uses a specialized secretion system, named ESX-1, to secrete EsxA, a homolog of the virulence determinants ESAT-6 and EsxA of Mycobacterium tuberculosis and Staphylococcus aureus, respectively. Our data show that the L. monocytogenes ESX-1 secretion system and its substrates are dispensable for bacterial invasion and intracellular multiplication in eukaryotic cell lines. Surprisingly, we found that the EssC-dependent secretion of EsxA has a detrimental effect on L. monocytogenes in vivo infection.
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Affiliation(s)
- Jorge Pinheiro
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal.,c Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto , Porto , Portugal
| | - Olga Reis
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal.,c Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto , Porto , Portugal
| | - Ana Vieira
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal
| | - Ines M Moura
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal
| | - Luisa Zanolli Moreno
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal.,d Laboratório de Saúde Pública , Faculdade de Saúde Pública, Universidade de São Paulo , São Paulo , Brazil
| | - Filipe Carvalho
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal.,c Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto , Porto , Portugal
| | - M Graciela Pucciarelli
- e Centro Nacional de Biotecnología-CSIC (CNB-CSIC) , Madrid , Spain.,f Departamento de Biología Molecular , Universidad Autónoma de Madrid, Centro de Biología Molecular "Severo Ochoa" (CBMSO-CSIC) , Madrid , Spain
| | | | - Sandra Sousa
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal
| | - Didier Cabanes
- a Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto , Porto , Portugal.,b Group of Molecular Microbiology , Instituto de Biologia Molecular e Celular - IBMC , Porto , Portugal
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Simeone R, Majlessi L, Enninga J, Brosch R. Perspectives on mycobacterial vacuole-to-cytosol translocation: the importance of cytosolic access. Cell Microbiol 2016; 18:1070-7. [DOI: 10.1111/cmi.12622] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 05/23/2016] [Accepted: 05/25/2016] [Indexed: 12/24/2022]
Affiliation(s)
- Roxane Simeone
- Institut Pasteur; Unit for Integrated Mycobacterial Pathogenomics; Paris France
| | - Laleh Majlessi
- Institut Pasteur; Unit for Integrated Mycobacterial Pathogenomics; Paris France
| | - Jost Enninga
- Institut Pasteur; Unit for Dynamics of host-pathogen interactions; Paris France
| | - Roland Brosch
- Institut Pasteur; Unit for Integrated Mycobacterial Pathogenomics; Paris France
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