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Manisha Y, Srinivasan M, Jobichen C, Rosenshine I, Sivaraman J. Sensing for survival: specialised regulatory mechanisms of Type III secretion systems in Gram-negative pathogens. Biol Rev Camb Philos Soc 2024; 99:837-863. [PMID: 38217090 DOI: 10.1111/brv.13047] [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: 10/20/2021] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/15/2024]
Abstract
For centuries, Gram-negative pathogens have infected the human population and been responsible for numerous diseases in animals and plants. Despite advancements in therapeutics, Gram-negative pathogens continue to evolve, with some having developed multi-drug resistant phenotypes. For the successful control of infections caused by these bacteria, we need to widen our understanding of the mechanisms of host-pathogen interactions. Gram-negative pathogens utilise an array of effector proteins to hijack the host system to survive within the host environment. These proteins are secreted into the host system via various secretion systems, including the integral Type III secretion system (T3SS). The T3SS spans two bacterial membranes and one host membrane to deliver effector proteins (virulence factors) into the host cell. This multifaceted process has multiple layers of regulation and various checkpoints. In this review, we highlight the multiple strategies adopted by these pathogens to regulate or maintain virulence via the T3SS, encompassing the regulation of small molecules to sense and communicate with the host system, as well as master regulators, gatekeepers, chaperones, and other effectors that recognise successful host contact. Further, we discuss the regulatory links between the T3SS and other systems, like flagella and metabolic pathways including the tricarboxylic acid (TCA) cycle, anaerobic metabolism, and stringent cell response.
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Affiliation(s)
- Yadav Manisha
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Mahalashmi Srinivasan
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, The Hebrew University of Jerusalem, Ein Kerem, Jerusalem, 91120, Israel
| | - J Sivaraman
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
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2
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Dufault-Thompson K, Jiang X. Annotating microbial functions with ProkFunFind. mSystems 2024; 9:e0003624. [PMID: 38364094 PMCID: PMC10949468 DOI: 10.1128/msystems.00036-24] [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: 01/10/2024] [Accepted: 01/22/2024] [Indexed: 02/18/2024] Open
Abstract
Analyzing microbial genomes has become an essential part of microbiology research, giving valuable insights into the functions and evolution of microbial species. Identifying genes of interest and assigning putative annotations to those genes is a central task in genome analysis, and a plethora of tools and approaches have been developed for this task. The ProkFunFind tool was developed to bridge the gap between these various annotation approaches, providing a flexible and customizable search approach to annotate microbial functions. ProkFunFind is designed around hierarchical definitions of biological functions, where individual genes can be identified using heterogeneous search terms consisting of sequences, profile hidden Markov models, protein domains, and orthology groups. This flexible and customizable search approach allows for searches to be tailored to specific biological functions, and the search results are output in multiple formats to facilitate downstream analyses. The utility of the ProkFunFind search tool was demonstrated through its application in searching for bacterial flagella, which are complex organelles composed of multiple genes. Overall, ProkFunFind provides an accessible and flexible way to integrate multiple types of annotation and sequence data while annotating biological functions in microbial genomes.IMPORTANCEGenome sequencing and analysis are increasingly important parts of microbiology, providing a way to predict metabolic functions, identify virulence factors, and understand the evolution of microbes. The expanded use of genome sequencing has also brought an abundance of search and annotation methods, but integrating the information from these different methods can be challenging and is often done through ad hoc approaches. To bridge the gap between different types of annotations, we developed ProkFunFind, a flexible and customizable search tool incorporating multiple search approaches and annotation types to annotate microbial functions. We demonstrated the utility of ProkFunFind by searching for gene clusters encoding flagellar genes using a combination of different annotation types and searches. Overall, ProkFunFind provides a reproducible and flexible way to identify gene clusters of interest, facilitating the meaningful analysis of new and existing microbial genomes.
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Affiliation(s)
| | - Xiaofang Jiang
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
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3
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Borkar SB, Negi M, Acharya TR, Lamichhane P, Kaushik N, Choi EH, Kaushik NK. Mitigation of T3SS-mediated virulence in waterborne pathogenic bacteria by multi-electrode cylindrical-DBD plasma-generated nitric oxide water. CHEMOSPHERE 2024; 350:140997. [PMID: 38128737 DOI: 10.1016/j.chemosphere.2023.140997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/06/2023] [Accepted: 12/18/2023] [Indexed: 12/23/2023]
Abstract
S. enterica, S. flexneri, and V. parahaemolyticus bacteria are globally recognized to cause severe diarrheal diseases, consisting of Type III Secretion System (T3SS) effectors that help in bacterial infection and virulence in host cells. This study investigates the properties of multi-electrode cylindrical DBD plasma-generated nitric oxide water (MCDBD-PG-NOW) treatment on the survival and virulence of S. enterica, S. flexneri, and V. parahaemolyticus bacteria. The Colony Forming Unit (CFU) assay, live/dead cell staining, lipid peroxidation assay, and bacteria morphological analysis showed substantial growth inhibition of bacteria. Moreover, to confirm the interaction of reactive nitrogen species (RNS) with bacterial membrane biotin switch assay, DAF-FM, and FTIR analysis were carried out, which established the formation of S-nitrosothiols in the cell membrane, intracellular accumulation of RNS, and changes in the cell composition post-PG-NOW treatment. Furthermore, the conventional culture-based method and a quantitative PCR using propidium monoazide showed minimal VBNC induction under similar condition. The efficiency of bacteria to adhere to mammalian colon cells was significantly reduced. In addition, the infection rate was also controlled by disrupting the virulent genes, leading to the collapse of the infection mechanism. This study provides insights into whether RNS generated from PG-NOW might be beneficial for preventing diarrheal infections.
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Affiliation(s)
- Shweta B Borkar
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Manorma Negi
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Tirtha Raj Acharya
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Prajwal Lamichhane
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea
| | - Neha Kaushik
- Department of Biotechnology, College of Engineering, The University of Suwon, Hwaseong, 18323, South Korea.
| | - Eun Ha Choi
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea.
| | - Nagendra Kumar Kaushik
- Department of Electrical and Biological Physics /Plasma Bioscience Research Center, Kwangwoon University, Seoul, 01897, South Korea.
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4
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Wimmi S, Fleck M, Helbig C, Brianceau C, Langenfeld K, Szymanski WG, Angelidou G, Glatter T, Diepold A. Pilotins are mobile T3SS components involved in assembly and substrate specificity of the bacterial type III secretion system. Mol Microbiol 2024; 121:304-323. [PMID: 38178634 DOI: 10.1111/mmi.15223] [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: 05/23/2023] [Revised: 12/17/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024]
Abstract
In animal pathogens, assembly of the type III secretion system injectisome requires the presence of so-called pilotins, small lipoproteins that assist the formation of the secretin ring in the outer membrane. Using a combination of functional assays, interaction studies, proteomics, and live-cell microscopy, we determined the contribution of the pilotin to the assembly, function, and substrate selectivity of the T3SS and identified potential new downstream roles of pilotin proteins. In absence of its pilotin SctG, Yersinia enterocolitica forms few, largely polar injectisome sorting platforms and needles. Accordingly, most export apparatus subcomplexes are mobile in these strains, suggesting the absence of fully assembled injectisomes. Remarkably, while absence of the pilotin all but prevents export of early T3SS substrates, such as the needle subunits, it has little effect on secretion of late T3SS substrates, including the virulence effectors. We found that although pilotins interact with other injectisome components such as the secretin in the outer membrane, they mostly localize in transient mobile clusters in the bacterial membrane. Together, these findings provide a new view on the role of pilotins in the assembly and function of type III secretion injectisomes.
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Affiliation(s)
- Stephan Wimmi
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Moritz Fleck
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Carlos Helbig
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Corentin Brianceau
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katja Langenfeld
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Witold G Szymanski
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Georgia Angelidou
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Timo Glatter
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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5
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Contreras-Moreno FJ, Pérez J, Muñoz-Dorado J, Moraleda-Muñoz A, Marcos-Torres FJ. Myxococcus xanthus predation: an updated overview. Front Microbiol 2024; 15:1339696. [PMID: 38328431 PMCID: PMC10849154 DOI: 10.3389/fmicb.2024.1339696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/15/2024] [Indexed: 02/09/2024] Open
Abstract
Bacterial predators are widely distributed across a variety of natural environments. Understanding predatory interactions is of great importance since they play a defining role in shaping microbial communities in habitats such as soils. Myxococcus xanthus is a soil-dwelling bacterial predator that can prey on Gram-positive and Gram-negative bacteria and even on eukaryotic microorganisms. This model organism has been studied for many decades for its unusual lifecycle, characterized by the formation of multicellular fruiting bodies filled with myxospores. However, less is known about its predatory behavior despite being an integral part of its lifecycle. Predation in M. xanthus is a multifactorial process that involves several mechanisms working synergistically, including motility systems to efficiently track and hunt prey, and a combination of short-range and contact-dependent mechanisms to achieve prey death and feed on them. In the short-range attack, M. xanthus is best known for the collective production of secondary metabolites and hydrolytic enzymes to kill prey and degrade cellular components. On the other hand, contact-dependent killing is a cell-to-cell process that relies on Tad-like and type III secretion systems. Furthermore, recent research has revealed that metals also play an important role during predation, either by inducing oxidative stress in the prey, or by competing for essential metals. In this paper, we review the current knowledge about M. xanthus predation, focusing on the different mechanisms used to hunt, kill, and feed on its prey, considering the most recent discoveries and the transcriptomic data available.
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Affiliation(s)
| | | | | | - Aurelio Moraleda-Muñoz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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Wimmi S, Balinovic A, Brianceau C, Pintor K, Vielhauer J, Turkowyd B, Helbig C, Fleck M, Langenfeld K, Kahnt J, Glatter T, Endesfelder U, Diepold A. Cytosolic sorting platform complexes shuttle type III secretion system effectors to the injectisome in Yersinia enterocolitica. Nat Microbiol 2024; 9:185-199. [PMID: 38172622 PMCID: PMC10769875 DOI: 10.1038/s41564-023-01545-1] [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: 09/23/2022] [Accepted: 11/06/2023] [Indexed: 01/05/2024]
Abstract
Bacteria use type III secretion injectisomes to inject effector proteins into eukaryotic target cells. Recruitment of effectors to the machinery and the resulting export hierarchy involve the sorting platform. These conserved proteins form pod structures at the cytosolic interface of the injectisome but are also mobile in the cytosol. Photoactivated localization microscopy in Yersinia enterocolitica revealed a direct interaction of the sorting platform proteins SctQ and SctL with effectors in the cytosol of live bacteria. These proteins form larger cytosolic protein complexes involving the ATPase SctN and the membrane connector SctK. The mobility and composition of these mobile pod structures are modulated in the presence of effectors and their chaperones, and upon initiation of secretion, which also increases the number of injectisomes from ~5 to ~18 per bacterium. Our quantitative data support an effector shuttling mechanism, in which sorting platform proteins bind to effectors in the cytosol and deliver the cargo to the export gate at the membrane-bound injectisome.
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Affiliation(s)
- Stephan Wimmi
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Alexander Balinovic
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
- Institute for Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Corentin Brianceau
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katherine Pintor
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Jan Vielhauer
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Bartosz Turkowyd
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
- Institute for Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Carlos Helbig
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Moritz Fleck
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katja Langenfeld
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Jörg Kahnt
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Timo Glatter
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Ulrike Endesfelder
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany.
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA.
- Institute for Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
| | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany.
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7
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Luo Y, Chen Z, Lian S, Ji X, Zhu C, Zhu G, Xia P. The Love and Hate Relationship between T5SS and Other Secretion Systems in Bacteria. Int J Mol Sci 2023; 25:281. [PMID: 38203452 PMCID: PMC10778856 DOI: 10.3390/ijms25010281] [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: 12/04/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
Bacteria have existed on Earth for billions of years, exhibiting ubiquity and involvement in various biological activities. To ensure survival, bacteria usually release and secrete effector proteins to acquire nutrients and compete with other microorganisms for living space during long-term evolution. Consequently, bacteria have developed a range of secretion systems, which are complex macromolecular transport machines responsible for transporting proteins across the bacterial cell membranes. Among them, one particular secretion system that stands out from the rest is the type V secretion system (T5SS), known as the "autotransporter". Bacterial activities mediated by T5SS include adherence to host cells or the extracellular matrix, invasion of host cells, immune evasion and serum resistance, contact-dependent growth inhibition, cytotoxicity, intracellular flow, protease activity, autoaggregation, and biofilm formation. In a bacterial body, it is not enough to rely on T5SS alone; in most cases, T5SS cooperates with other secretion systems to carry out bacterial life activities, but regardless of how good the relationship is, there is friction between the secretion systems. T5SS and T1SS/T2SS/T3SS/T6SS all play a synergistic role in the pathogenic processes of bacteria, such as nutrient acquisition, pathogenicity enhancement, and immune modulation, but T5SS indirectly inhibits the function of T4SS. This could be considered a love-hate relationship between secretion systems. This paper uses the systematic literature review methodology to review 117 journal articles published within the period from 1995 to 2024, which are all available from the PubMed, Web of Science, and Scopus databases and aim to elucidate the link between T5SS and other secretion systems, providing clues for future prevention and control of bacterial diseases.
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Affiliation(s)
- Yi Luo
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou 225009, China; (Y.L.); (Z.C.); (S.L.); (X.J.); (G.Z.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- International Research Laboratory of Prevention and Control of Important Animal Infectious Diseases and Zoonotic Diseases of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
| | - Ziyue Chen
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou 225009, China; (Y.L.); (Z.C.); (S.L.); (X.J.); (G.Z.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- International Research Laboratory of Prevention and Control of Important Animal Infectious Diseases and Zoonotic Diseases of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
| | - Siqi Lian
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou 225009, China; (Y.L.); (Z.C.); (S.L.); (X.J.); (G.Z.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- International Research Laboratory of Prevention and Control of Important Animal Infectious Diseases and Zoonotic Diseases of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
| | - Xingduo Ji
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou 225009, China; (Y.L.); (Z.C.); (S.L.); (X.J.); (G.Z.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- International Research Laboratory of Prevention and Control of Important Animal Infectious Diseases and Zoonotic Diseases of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
| | - Chunhong Zhu
- Jiangsu Institute of Poultry Science, Yangzhou 225009, China;
| | - Guoqiang Zhu
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou 225009, China; (Y.L.); (Z.C.); (S.L.); (X.J.); (G.Z.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- International Research Laboratory of Prevention and Control of Important Animal Infectious Diseases and Zoonotic Diseases of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
| | - Pengpeng Xia
- College of Veterinary Medicine (Institute of Comparative Medicine), Yangzhou University, Yangzhou 225009, China; (Y.L.); (Z.C.); (S.L.); (X.J.); (G.Z.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
- International Research Laboratory of Prevention and Control of Important Animal Infectious Diseases and Zoonotic Diseases of Jiangsu Higher Education Institutions, Yangzhou University, Yangzhou 225009, China
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Rubio-Mendoza D, Martínez-Meléndez A, Maldonado-Garza HJ, Córdova-Fletes C, Garza-González E. Review of the Impact of Biofilm Formation on Recurrent Clostridioides difficile Infection. Microorganisms 2023; 11:2525. [PMID: 37894183 PMCID: PMC10609348 DOI: 10.3390/microorganisms11102525] [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: 09/05/2023] [Revised: 09/25/2023] [Accepted: 09/29/2023] [Indexed: 10/29/2023] Open
Abstract
Clostridioides difficile infection (CDI) may recur in approximately 10-30% of patients, and the risk of recurrence increases with each successive recurrence, reaching up to 65%. C. difficile can form biofilm with approximately 20% of the bacterial genome expressed differently between biofilm and planktonic cells. Biofilm plays several roles that may favor recurrence; for example, it may act as a reservoir of spores, protect the vegetative cells from the activity of antibiotics, and favor the formation of persistent cells. Moreover, the expression of several virulence genes, including TcdA and TcdB toxins, has been associated with recurrence. Several systems and structures associated with adhesion and biofilm formation have been studied in C. difficile, including cell-wall proteins, quorum sensing (including LuxS and Agr), Cyclic di-GMP, type IV pili, and flagella. Most antibiotics recommended for the treatment of CDI do not have activity on spores and do not eliminate biofilm. Therapeutic failure in R-CDI has been associated with the inadequate concentration of drugs in the intestinal tract and the antibiotic resistance of a biofilm. This makes it challenging to eradicate C. difficile in the intestine, complicating antibacterial therapies and allowing non-eliminated spores to remain in the biofilm, increasing the risk of recurrence. In this review, we examine the role of biofilm on recurrence and the challenges of treating CDI when the bacteria form a biofilm.
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Affiliation(s)
- Daira Rubio-Mendoza
- Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico; (D.R.-M.); (H.J.M.-G.); (C.C.-F.)
| | - Adrián Martínez-Meléndez
- Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza 66455, Mexico;
| | - Héctor Jesús Maldonado-Garza
- Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico; (D.R.-M.); (H.J.M.-G.); (C.C.-F.)
| | - Carlos Córdova-Fletes
- Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico; (D.R.-M.); (H.J.M.-G.); (C.C.-F.)
| | - Elvira Garza-González
- Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico; (D.R.-M.); (H.J.M.-G.); (C.C.-F.)
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9
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Huang W, Chen W, Chen Y, Fang S, Huang T, Chang P, Chang Y. Salmonella YqiC exerts its function through an oligomeric state. Protein Sci 2023; 32:e4749. [PMID: 37555831 PMCID: PMC10503411 DOI: 10.1002/pro.4749] [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: 04/27/2023] [Revised: 07/18/2023] [Accepted: 08/07/2023] [Indexed: 08/10/2023]
Abstract
Protein oligomerization occurs frequently both in vitro and in vivo, with specific functionalities associated with different oligomeric states. The YqiC protein from Salmonella Typhimurium forms a homotrimer through its C-terminal coiled-coil domain, and the protein is closely linked to the colonization and invasion of the bacteria to the host cells. To elucidate the importance of the oligomeric state of YqiC in vivo and its relation with bacterial infection, we mutated crucial residues in YqiC's coiled-coil region and confirmed the loss of trimer formation using chemical crosslinking and size exclusion chromatography coupled with multiple angle light scattering (SEC-MALS) techniques. The yqiC-knockout strain complemented with mutant YqiC showed significantly reduced colonization and invasion of Salmonella to host cells, demonstrating the critical role of YqiC oligomerization in bacterial pathogenesis. Furthermore, we conducted a protein-protein interaction study of YqiC using a pulled-down assay coupled with mass spectrometry analysis to investigate the protein's role in bacterial virulence. The results reveal that YqiC interacts with subunits of Complex II of the electron transport chain (SdhA and SdhB) and the β-subunit of F0 F1 -ATP synthase. These interactions suggest that YqiC may modulate the energy production of Salmonella and subsequently affect the assembly of crucial virulence factors, such as flagella. Overall, our findings provide new insights into the molecular mechanisms of YqiC's role in S. Typhimurium pathogenesis and suggest potential therapeutic targets for bacterial infections.
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Affiliation(s)
- Wei‐Chun Huang
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Wai‐Ting Chen
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Yueh‐Chen Chen
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Shiuh‐Bin Fang
- Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, Shuang Ho HospitalTaipei Medical UniversityTaipeiTaiwan
- Department of Pediatrics, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
- Master Program for Clinical Genomics and Proteomics, College of PharmacyTaipei Medical UniversityTaipeiTaiwan
| | - Tzu‐Wen Huang
- Department of Microbiology and Immunology, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Pei‐Ru Chang
- Division of Pediatric Gastroenterology and Hepatology, Department of Pediatrics, Shuang Ho HospitalTaipei Medical UniversityTaipeiTaiwan
- Department of Pediatrics, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Yu‐Chu Chang
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
- Graduate Institute of Medical Sciences, College of MedicineTaipei Medical UniversityTaipeiTaiwan
- International PhD Program in Cell Therapy and Regenerative Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
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10
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Soto JE, Lara-Tejero M. The sorting platform in the type III secretion pathway: From assembly to function. Bioessays 2023; 45:e2300078. [PMID: 37329195 DOI: 10.1002/bies.202300078] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
The type III secretion system (T3SS) is a specialized nanomachine that enables bacteria to secrete proteins in a specific order and directly deliver a specific set of them, collectively known as effectors, into eukaryotic organisms. The core structure of the T3SS is a syringe-like apparatus composed of multiple building blocks, including both membrane-associated and soluble proteins. The cytosolic components organize together in a chamber-like structure known as the sorting platform (SP), responsible for recruiting, sorting, and initiating the substrates destined to engage this secretion pathway. In this article, we provide an overview of recent findings on the SP's structure and function, with a particular focus on its assembly pathway. Furthermore, we discuss the molecular mechanisms behind the recruitment and hierarchical sorting of substrates by this cytosolic complex. Overall, the T3SS is a highly specialized and complex system that requires precise coordination to function properly. A deeper understanding of how the SP orchestrates T3S could enhance our comprehension of this complex nanomachine, which is central to the host-pathogen interface, and could aid in the development of novel strategies to fight bacterial infections.
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Affiliation(s)
- Jose Eduardo Soto
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - María Lara-Tejero
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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11
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Rocha ST, Shah DD, Zhu Q, Shrivastava A. The prevalence of motility within the human oral microbiota. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.17.549387. [PMID: 37503047 PMCID: PMC10370060 DOI: 10.1101/2023.07.17.549387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The human oral and nasal microbiota contains approximately 770 cultivable bacterial species. More than 2000 genome sequences of these bacteria can be found in the expanded Human Oral Microbiome Database (eHOMD). We developed HOMDscrape, a freely available Python software tool to programmatically retrieve and process amino acid sequences and sequence identifiers from BLAST results acquired from the eHOMD website. Using the data obtained through HOMDscrape, the phylogeny of proteins involved in bacterial flagellar motility, Type 4 pilus driven twitching motility, and Type 9 Secretion system (T9SS) driven gliding motility was constructed. A comprehensive phylogenetic analysis was conducted for all components of the rotary T9SS, a machinery responsible for secreting various enzymes, virulence factors, and enabling bacterial gliding motility. Results revealed that the T9SS outer membrane ß-barrel protein SprA of human oral microbes underwent horizontal evolution. Overall, we catalog motile microbes that inhabit the human oral microbiota and document their evolutionary connections. These results will serve as a guide for further studies exploring the impact of motility on shaping of the human oral microbiota.
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12
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Saleh DO, Horstmann JA, Giralt-Zúñiga M, Weber W, Kaganovitch E, Durairaj AC, Klotzsch E, Strowig T, Erhardt M. SPI-1 virulence gene expression modulates motility of Salmonella Typhimurium in a proton motive force- and adhesins-dependent manner. PLoS Pathog 2023; 19:e1011451. [PMID: 37315106 DOI: 10.1371/journal.ppat.1011451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
Both the bacterial flagellum and the evolutionary related injectisome encoded on the Salmonella pathogenicity island 1 (SPI-1) play crucial roles during the infection cycle of Salmonella species. The interplay of both is highlighted by the complex cross-regulation that includes transcriptional control of the flagellar master regulatory operon flhDC by HilD, the master regulator of SPI-1 gene expression. Contrary to the HilD-dependent activation of flagellar gene expression, we report here that activation of HilD resulted in a dramatic loss of motility, which was dependent on the presence of SPI-1. Single cell analyses revealed that HilD-activation triggers a SPI-1-dependent induction of the stringent response and a substantial decrease in proton motive force (PMF), while flagellation remains unaffected. We further found that HilD activation enhances the adhesion of Salmonella to epithelial cells. A transcriptome analysis revealed a simultaneous upregulation of several adhesin systems, which, when overproduced, phenocopied the HilD-induced motility defect. We propose a model where the SPI-1-dependent depletion of the PMF and the upregulation of adhesins upon HilD-activation enable flagellated Salmonella to rapidly modulate their motility during infection, thereby enabling efficient adhesion to host cells and delivery of effector proteins.
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Affiliation(s)
- Doaa Osama Saleh
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Julia A Horstmann
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - María Giralt-Zúñiga
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Willi Weber
- Institute for Biology, Experimental Biophysics/Mechanobiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Eugen Kaganovitch
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Abilash Chakravarthy Durairaj
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Department of Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Enrico Klotzsch
- Institute for Biology, Experimental Biophysics/Mechanobiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Till Strowig
- Department of Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Marc Erhardt
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
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13
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Schott S, Scheuer R, Ermoli F, Glatter T, Evguenieva-Hackenberg E, Diepold A. A ParDE toxin-antitoxin system is responsible for the maintenance of the Yersinia virulence plasmid but not for type III secretion-associated growth inhibition. Front Cell Infect Microbiol 2023; 13:1166077. [PMID: 37228670 PMCID: PMC10203498 DOI: 10.3389/fcimb.2023.1166077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/20/2023] [Indexed: 05/27/2023] Open
Abstract
Many Gram-negative pathogens utilize the type III secretion system (T3SS) to translocate virulence-promoting effector proteins into eukaryotic host cells. The activity of this system results in a severe reduction of bacterial growth and division, summarized as secretion-associated growth inhibition (SAGI). In Yersinia enterocolitica, the T3SS and related proteins are encoded on a virulence plasmid. We identified a ParDE-like toxin-antitoxin system on this virulence plasmid in genetic proximity to yopE, encoding a T3SS effector. Effectors are strongly upregulated upon activation of the T3SS, indicating a potential role of the ParDE system in the SAGI or maintenance of the virulence plasmid. Expression of the toxin ParE in trans resulted in reduced growth and elongated bacteria, highly reminiscent of the SAGI. Nevertheless, the activity of ParDE is not causal for the SAGI. T3SS activation did not influence ParDE activity; conversely, ParDE had no impact on T3SS assembly or activity itself. However, we found that ParDE ensures the presence of the T3SS across bacterial populations by reducing the loss of the virulence plasmid, especially under conditions relevant to infection. Despite this effect, a subset of bacteria lost the virulence plasmid and regained the ability to divide under secreting conditions, facilitating the possible emergence of T3SS-negative bacteria in late acute and persistent infections.
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Affiliation(s)
- Saskia Schott
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Robina Scheuer
- Department of Microbiology and Molecular Biology, Justus Liebig University Gießen, Gießen, Germany
| | - Francesca Ermoli
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Timo Glatter
- Core Facility for Mass spectrometry & Proteomics, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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14
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Koroleva EA, Soloveva AV, Morgunova EY, Kapotina LN, Luyksaar SI, Luyksaar SV, Bondareva NE, Nelubina SA, Lubenec NL, Zigangirova NA, Gintsburg AL. Fluorothiazinon inhibits the virulence factors of uropathogenic Escherichia coli involved in the development of urinary tract infection. J Antibiot (Tokyo) 2023; 76:279-290. [PMID: 36922636 DOI: 10.1038/s41429-023-00602-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/01/2023] [Accepted: 02/10/2023] [Indexed: 03/18/2023]
Abstract
Uropathogenic Escherichia coli (UPEC) is the most common pathogenic bacterium associated with urinary tract infection. Due to the development of antibiotic resistance and MDR, UPEC infection has become a serious problem in the last decade. In order to combat resistance, it is necessary to develop innovative antimicrobial agents that act by different mechanisms than conventional antibiotics. Among the new therapeutic strategies, suppression of pathogen virulence has become a promising alternative, since it fundamentally reduces selective pressure and the development of resistance. In our study, we showed that the compound Fluorothiazinon suppressed UPEC's ability to form biofilms and to move using the flagellum, as well as to penetrate into cells. Prophylactic use with subsequent treatment of FT in rodent models led to an improvement in survival and significantly reduced the bacterial load in the organs of the urinary system, thereby inhibiting the development of ascending infection and preventing the development of pathological changes in prostate tissues. These results suggest that FT affects several UPEC virulence factors at once and if similar results can be found in clinical trials it can potentially be used as a new drug against UPEC.
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Affiliation(s)
- E A Koroleva
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia.
| | - A V Soloveva
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - E Y Morgunova
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - L N Kapotina
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - S I Luyksaar
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - S V Luyksaar
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - N E Bondareva
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - S A Nelubina
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - N L Lubenec
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - N A Zigangirova
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia
| | - A L Gintsburg
- National Research Center of Epidemiology and Microbiology n. a. N.F. Gamaleya, Russian Ministry of Health, Moscow, 123098, Russia.,I.M. Sechenov First Moscow State Medical University, Moscow, 119992, Russia
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15
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Barak-Gavish N, Dassa B, Kuhlisch C, Nussbaum I, Brandis A, Rosenberg G, Avraham R, Vardi A. Bacterial lifestyle switch in response to algal metabolites. eLife 2023; 12:e84400. [PMID: 36691727 PMCID: PMC9873259 DOI: 10.7554/elife.84400] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/05/2023] [Indexed: 01/19/2023] Open
Abstract
Unicellular algae, termed phytoplankton, greatly impact the marine environment by serving as the basis of marine food webs and by playing central roles in the biogeochemical cycling of elements. The interactions between phytoplankton and heterotrophic bacteria affect the fitness of both partners. It is becoming increasingly recognized that metabolic exchange determines the nature of such interactions, but the underlying molecular mechanisms remain underexplored. Here, we investigated the molecular and metabolic basis for the bacterial lifestyle switch, from coexistence to pathogenicity, in Sulfitobacter D7 during its interaction with Emiliania huxleyi, a cosmopolitan bloom-forming phytoplankter. To unravel the bacterial lifestyle switch, we analyzed bacterial transcriptomes in response to exudates derived from algae in exponential growth and stationary phase, which supported the Sulfitobacter D7 coexistence and pathogenicity lifestyles, respectively. In pathogenic mode, Sulfitobacter D7 upregulated flagellar motility and diverse transport systems, presumably to maximize assimilation of E. huxleyi-derived metabolites released by algal cells upon cell death. Algal dimethylsulfoniopropionate (DMSP) was a pivotal signaling molecule that mediated the transition between the lifestyles, supporting our previous findings. However, the coexisting and pathogenic lifestyles were evident only in the presence of additional algal metabolites. Specifically, we discovered that algae-produced benzoate promoted the growth of Sulfitobacter D7 and hindered the DMSP-induced lifestyle switch to pathogenicity, demonstrating that benzoate is important for maintaining the coexistence of algae and bacteria. We propose that bacteria can sense the physiological state of the algal host through changes in the metabolic composition, which will determine the bacterial lifestyle during interaction.
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Affiliation(s)
- Noa Barak-Gavish
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Bareket Dassa
- Life Sciences Core Facilities, Weizmann Institute of ScienceRehovotIsrael
| | - Constanze Kuhlisch
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Inbal Nussbaum
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Alexander Brandis
- Life Sciences Core Facilities, Weizmann Institute of ScienceRehovotIsrael
| | - Gili Rosenberg
- Department of Biological Regulation, Weizmann Institute of ScienceRehovotIsrael
| | - Roi Avraham
- Department of Biological Regulation, Weizmann Institute of ScienceRehovotIsrael
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
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16
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Guzmán-Herrador DL, Fernández-Gómez A, Llosa M. Recruitment of heterologous substrates by bacterial secretion systems for transkingdom translocation. Front Cell Infect Microbiol 2023; 13:1146000. [PMID: 36949816 PMCID: PMC10025392 DOI: 10.3389/fcimb.2023.1146000] [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: 01/16/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023] Open
Abstract
Bacterial secretion systems mediate the selective exchange of macromolecules between bacteria and their environment, playing a pivotal role in processes such as horizontal gene transfer or virulence. Among the different families of secretion systems, Type III, IV and VI (T3SS, T4SS and T6SS) share the ability to inject their substrates into human cells, opening up the possibility of using them as customized injectors. For this to happen, it is necessary to understand how substrates are recruited and to be able to engineer secretion signals, so that the transmembrane machineries can recognize and translocate the desired substrates in place of their own. Other factors, such as recruiting proteins, chaperones, and the degree of unfolding required to cross through the secretion channel, may also affect transport. Advances in the knowledge of the secretion mechanism have allowed heterologous substrate engineering to accomplish translocation by T3SS, and to a lesser extent, T4SS and T6SS into human cells. In the case of T4SS, transport of nucleoprotein complexes adds a bonus to its biotechnological potential. Here, we review the current knowledge on substrate recognition by these secretion systems, the many examples of heterologous substrate translocation by engineering of secretion signals, and the current and future biotechnological and biomedical applications derived from this approach.
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17
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Prindle JR, Wang Y, Rocha JM, Diepold A, Gahlmann A. Distinct Cytosolic Complexes Containing the Type III Secretion System ATPase Resolved by Three-Dimensional Single-Molecule Tracking in Live Yersinia enterocolitica. Microbiol Spectr 2022; 10:e0174422. [PMID: 36354362 PMCID: PMC9769973 DOI: 10.1128/spectrum.01744-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/20/2022] [Indexed: 11/12/2022] Open
Abstract
The membrane-embedded injectisome, the structural component of the virulence-associated type III secretion system (T3SS), is used by Gram-negative bacterial pathogens to inject species-specific effector proteins into eukaryotic host cells. The cytosolic injectisome proteins are required for export of effectors and display both stationary, injectisome-bound populations and freely diffusing cytosolic populations. How the cytosolic injectisome proteins interact with each other in the cytosol and associate with membrane-embedded injectisomes remains unclear. Here, we utilized three-dimensional (3D) single-molecule tracking to resolve distinct cytosolic complexes of injectisome proteins in living Yersinia enterocolitica cells. Tracking of the enhanced yellow fluorescent protein (eYFP)-labeled ATPase YeSctN and its regulator, YeSctL, revealed that these proteins form a cytosolic complex with each other and then further with YeSctQ. YeSctNL and YeSctNLQ complexes can be observed both in wild-type cells and in ΔsctD mutants, which cannot assemble injectisomes. In ΔsctQ mutants, the relative abundance of the YeSctNL complex is considerably increased. These data indicate that distinct cytosolic complexes of injectisome proteins can form prior to injectisome binding, which has important implications for how injectisomes are functionally regulated. IMPORTANCE Injectisomes are membrane-embedded, multiprotein assemblies used by bacterial pathogens to inject virulent effector proteins into eukaryotic host cells. Protein secretion is regulated by cytosolic proteins that dynamically bind and unbind at injectisomes. However, how these regulatory proteins interact with each other remains unknown. By measuring the diffusion rates of single molecules in living cells, we show that cytosolic injectisome proteins form distinct oligomeric complexes with each other prior to binding to injectisomes. We additionally identify the molecular compositions of these complexes and quantify their relative abundances. Quantifying to what extent cytosolic proteins exist as part of larger complexes in living cells has important implications for deciphering the complexity of biomolecular mechanisms. The results and methods reported here are thus relevant for advancing our understanding of how injectisomes and related multiprotein assemblies, such as bacterial flagellar motors, are functionally regulated.
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Affiliation(s)
- Joshua R. Prindle
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Yibo Wang
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Julian M. Rocha
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Andreas Diepold
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Andreas Gahlmann
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology & Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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18
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Abstract
Type III secretion systems are bacterial nanomachines specialized in protein delivery into target eukaryotic cells. The structural and functional complexity of these machines demands highly coordinated mechanisms for their assembly and operation. The sorting platform is a critical component of type III secretion machines that ensures the timely engagement and secretion of proteins destined to travel this export pathway. However, the mechanisms that lead to the assembly of this multicomponent structure have not been elucidated. Herein, employing an extensive in vivo cross-linking strategy aided by structure modeling, we provide a detailed intersubunit contact survey of the entire sorting platform complex. Using the identified cross-links as signatures for pairwise intersubunit interactions in combination with systematic genetic deletions, we mapped the assembly process of this unique bacterial structure. Insights generated by this study could serve as the bases for the rational development of antivirulence strategies to combat several medically important bacterial pathogens.
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19
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Aljghami ME, Barghash MM, Majaesic E, Bhandari V, Houry WA. Cellular functions of the ClpP protease impacting bacterial virulence. Front Mol Biosci 2022; 9:1054408. [PMID: 36533084 PMCID: PMC9753991 DOI: 10.3389/fmolb.2022.1054408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/15/2022] [Indexed: 09/28/2023] Open
Abstract
Proteostasis mechanisms significantly contribute to the sculpting of the proteomes of all living organisms. ClpXP is a central AAA+ chaperone-protease complex present in both prokaryotes and eukaryotes that facilitates the unfolding and subsequent degradation of target substrates. ClpX is a hexameric unfoldase ATPase, while ClpP is a tetradecameric serine protease. Substrates of ClpXP belong to many cellular pathways such as DNA damage response, metabolism, and transcriptional regulation. Crucially, disruption of this proteolytic complex in microbes has been shown to impact the virulence and infectivity of various human pathogenic bacteria. Loss of ClpXP impacts stress responses, biofilm formation, and virulence effector protein production, leading to decreased pathogenicity in cell and animal infection models. Here, we provide an overview of the multiple critical functions of ClpXP and its substrates that modulate bacterial virulence with examples from several important human pathogens.
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Affiliation(s)
- Mazen E. Aljghami
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Marim M. Barghash
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Emily Majaesic
- Department of Chemistry, University of Toronto, Toronto, ON, Canada
| | - Vaibhav Bhandari
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Walid A. Houry
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Department of Chemistry, University of Toronto, Toronto, ON, Canada
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20
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Yuan B, Ma Y, Ren J, Ding G, Zhou N, Liang J, Sun Y. Risk assessment of three sheep stocking modes via identification of bacterial genomes carrying antibiotic resistance genes and virulence factor genes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 323:116270. [PMID: 36261965 DOI: 10.1016/j.jenvman.2022.116270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 06/15/2022] [Accepted: 09/11/2022] [Indexed: 06/16/2023]
Abstract
In order to protect the prairie ecological environment, intensive farming has become a prevalent method of sheep stocking. However, the link between captivity stocking mode and ecological risk of sheep feces is still poorly understood. In this study, metagenomics was used to identify the environmental risk of sheep feces among three stocking modes. Our results showed that captivity mode (C) elevated antibiotic resistance in feces, with the abundance of antibiotic resistance genes (ARGs) (5.381 copies/cell) higher than that of half-pen stocking (Fh) (1.093 copies/cell) and grazing mode (Fr) (0.315 copies/cell) (Duncan's test, P < 0.05). Virulence factor genes (VFGs) analysis showed offensive virulence factors had the highest abundance in captivity feces (C: 3.826 copies/cell, Fh: 0.342 copies/cell, Fr: 0.163 copies/cell) (Duncan's test, P < 0.05). 15 metagenome-assembled genomes (MAGs) were identified as potential pathogenic antibiotic resistant bacteria (PARB) and revealed that Escherichia, Klebsiella may be the main host of ARGs and VFGs in sheep feces. Furthermore, the minimal inhibition concentrations (MIC) of tetracycline of E. coli in the captivity feces was 8.6 times and 4.7 times than that of grazing and half-pen stocking samples, respectively. The Non-metric multidimensional scaling (NMDS) revealed that high stocking density leads to feces causing increased harm to the environment. Although feces from sheep raised in captivity and half-pen stocking modes are easier to collect, they are more harmful to the environment and aerobic composting should be done before their application to farmland. This work provides a guideline for better control of the environmental risk of sheep feces from different stocking modes.
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Affiliation(s)
- Bo Yuan
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
| | - Yanwen Ma
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Jingyao Ren
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Guochun Ding
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Ningcong Zhou
- Ulanqab Animal Husbandry Station of Inner Mongolia Autonomous Region, Inner Mongolia, 012000, China
| | - Jinsong Liang
- School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, 518055, China.
| | - Ying Sun
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
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21
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Schwan M, Khaledi A, Willger S, Papenfort K, Glatter T, Häußler S, Thormann KM. FlrA-independent production of flagellar proteins is required for proper flagellation in Shewanella putrefaciens. Mol Microbiol 2022; 118:670-682. [PMID: 36285560 DOI: 10.1111/mmi.14993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 01/18/2023]
Abstract
Flagella are multiprotein complexes whose assembly and positioning require complex spatiotemporal control. Flagellar assembly is thought to be controlled by several transcriptional tiers, which are mediated through various master regulators. Here, we revisited the regulation of flagellar genes in polarly flagellated gammaproteobacteria by the regulators FlrA, RpoN (σ54 ) and FliA (σ28 ) in Shewanella putrefaciens CN-32 at the transcript and protein level. We found that a number of regulatory and structural proteins were present in the absence of the main regulators, suggesting that initiation of flagella assembly and motor activation relies on the abundance control of only a few structural key components that are required for the formation of the MS- and C-ring and the flagellar type III secretion system. We identified FlrA-independent promoters driving expression of the regulators of flagellar number and positioning, FlhF and FlhG. Reduction of the gene expression levels from these promoters resulted in the emergence of hyperflagellation. This finding indicates that basal expression is required to adjust the flagellar counter in Shewanella. This is adding a deeper layer to the regulation of flagellar synthesis and assembly.
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Affiliation(s)
- Meike Schwan
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität, Giessen, Germany
| | - Ariane Khaledi
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sven Willger
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Kai Papenfort
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - Timo Glatter
- Max Planck Institute for Terrestrial Microbiology, Mass Spectrometry and Proteomics, Marburg, Germany
| | - Susanne Häußler
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Kai M Thormann
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität, Giessen, Germany
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22
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Characterization of a Pseudokeronopsis Strain (Ciliophora, Urostylida) and Its Bacterial Endosymbiont “Candidatus Trichorickettsia” (Alphaproteobacteria, Rickettsiales). DIVERSITY 2022. [DOI: 10.3390/d14121032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Symbiotic associations between bacteria and ciliate protists are rather common. In particular, several cases were reported involving bacteria of the alphaproteobacterial lineage Rickettsiales, but the diversity, features, and interactions in these associations are still poorly understood. In this work, we characterized a novel ciliate protist strain originating from Brazil and its associated Rickettsiales endosymbiont by means of live and ultrastructural observations, as well as molecular phylogeny. Though with few morphological peculiarities, the ciliate was found to be phylogenetically affiliated with Pseudokeronopsis erythrina, a euryhaline species, which is consistent with its origin from a lagoon with significant spatial and seasonal salinity variations. The bacterial symbiont was assigned to “Candidatus Trichorickettsia mobilis subsp. hyperinfectiva”, being the first documented case of a Rickettsiales associated with urostylid ciliates. It resided in the host cytoplasm and bore flagella, similarly to many, but not all, conspecifics in other host species. These findings highlight the ability of “Candidatus Trichorickettsia” to infect multiple distinct host species and underline the importance of further studies on this system, in particular on flagella and their regulation, from a functional and also an evolutionary perspective, considering the phylogenetic proximity with the well-studied and non-flagellated Rickettsia.
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The Assembly of Flagella in Enteropathogenic Escherichia coli Requires the Presence of a Functional Type III Secretion System. Int J Mol Sci 2022; 23:ijms232213705. [PMID: 36430181 PMCID: PMC9694695 DOI: 10.3390/ijms232213705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
In enteropathogenic Escherichia coli (EPEC), the production of flagella and the type III secretion system (T3SS) is activated in the presence of host cultured epithelial cells. The goal of this study was to investigate the relationship between expression of flagella and the T3SS. Mutants deficient in assembling T3SS basal and translocon components (ΔespA, ΔespB, ΔespD, ΔescC, ΔescN, and ΔescV), and in secreting effector molecules (ΔsepD and ΔsepL) were tested for flagella production under several growth conditions. The ΔespA mutant did not produce flagella in any condition tested, although fliC was transcribed. The remaining mutants produced different levels of flagella upon growth in LB or in the presence of cells but were significantly diminished in flagella production after growth in Dulbecco's minimal essential medium. We also investigated the role of virulence and global regulator genes in expression of flagella. The ΔqseB and ΔqseC mutants produced abundant flagella only when growing in LB and in the presence of HeLa cells, indicating that QseB and QseC act as negative regulators of fliC transcription. The ΔgrlR, ΔperA, Δler, Δhns, and Δfis mutants produced low levels of flagella, suggesting these regulators are activators of fliC expression. These data suggest that the presence of an intact T3SS is required for assembly of flagella highlighting the existence in EPEC of a cross-talk between these two virulence-associated T3SSs.
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Shi Y, Chen X, Shu J, Liu Y, Zhang Y, Lv Q, Wang J, Deng X, Liu H, Qiu J. Harmine, an inhibitor of the type III secretion system of Salmonella enterica serovar Typhimurium. Front Cell Infect Microbiol 2022; 12:967149. [PMID: 36176578 PMCID: PMC9513467 DOI: 10.3389/fcimb.2022.967149] [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: 06/12/2022] [Accepted: 08/22/2022] [Indexed: 12/02/2022] Open
Abstract
New therapeutic strategies for clinical Salmonella enterica serovar Typhimurium (S. Typhimurium) infection are urgently needed due to the generation of antibiotic-resistant bacteria. Inhibition of bacterial virulence has been increasingly regarded as a potential and innovative strategy for the development of anti-infection drugs. Salmonella pathogenicity island (SPI)-encoded type III secretion system (T3SS) represents a key virulence factor in S. Typhimurium, and active invasion and replication in host cells is facilitated by the secretion of T3SS effector proteins. In this study, we found that harmine could inhibit T3SS secretion; thus, its potential anti-S. Typhimurium infection activity was elucidated. Harmine inhibits the secretion and expression of T3SS effector proteins and consequently attenuates the S. Typhimurium invasion function of HeLa cells. This inhibition may be implemented by reducing the transcription of pathogenesis-related SPI-1 transcriptional activator genes hilD, hilC, and rtsA. Harmine improves the survival rate and bacterial loads of mice infected with S. Typhimurium. In summary, harmine, an effective T3SS inhibitor, could be a leading compound for the development of treatments for Salmonella infection.
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Affiliation(s)
- Yunjia Shi
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xindi Chen
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jingyan Shu
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yang Liu
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yong Zhang
- Department of Respiratory Medicine, Center for Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, State Key Laboratory for Zoonotic Diseases, The First Hospital of Jilin University, Changchun, China
| | - Qianghua Lv
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jianfeng Wang
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuming Deng
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Hongtao Liu
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
- *Correspondence: Jiazhang Qiu, ; Hongtao Liu,
| | - Jiazhang Qiu
- Laboratory for Zoonotic Diseases, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
- *Correspondence: Jiazhang Qiu, ; Hongtao Liu,
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Thiery S, Turowski P, Berleman JE, Kaimer C. The predatory soil bacterium Myxococcus xanthus combines a Tad- and an atypical type 3-like protein secretion system to kill bacterial cells. Cell Rep 2022; 40:111340. [PMID: 36103818 DOI: 10.1016/j.celrep.2022.111340] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/20/2022] [Accepted: 08/18/2022] [Indexed: 11/03/2022] Open
Abstract
Predatory Myxobacteria employ a multilayered predation strategy to kill and lyse soil microorganisms. Aiming to dissect the mechanism of contact-dependent killing of bacteria, we analyze four protein secretion systems in Myxococcus xanthus and investigate the predation of mutant strains on different timescales. We find that a Tad-like and a type 3-like secretion system (Tad and T3SS∗) fulfill distinct functions during contact-dependent prey killing: the Tad-like system is necessary to induce prey cell death, while the needle-less T3SS∗ initiates prey lysis. Fluorescence microscopy reveals that components of both systems interdependently localize to the predator-prey contact site prior to killing. Swarm expansion assays show that both Tad and T3SS∗ are required to handle live prey and that nutrient extraction from prey bacteria is sufficient to power M. xanthus motility. In conclusion, our observations indicate the functional interplay of two types of secretion systems for killing and lysis of bacterial cells.
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Affiliation(s)
- Susanne Thiery
- Department of Biology and Biotechnology, Microbial Biology, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Pia Turowski
- Department of Biology and Biotechnology, Microbial Biology, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - James E Berleman
- Department of Biology, St. Mary's College, Moraga, CA 94556, USA
| | - Christine Kaimer
- Department of Biology and Biotechnology, Microbial Biology, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany.
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Kumar R, Roy C, Datta S. Delineating specific regions of N- terminal domain of T3SS ATPase YsaN of Yersinia enterocolitica governing its different oligomerization states. Front Mol Biosci 2022; 9:967974. [PMID: 36158578 PMCID: PMC9493007 DOI: 10.3389/fmolb.2022.967974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
Oligomerization of YsaN, a putative T3SS-ATPase is a necessary and crucial event for T3SS functioning in Y. enterocolitica. Different oligomeric states have been proposed for similar ATPases, yet, the true nature of its activation and formation of different oligomers is still poorly understood. In-vitro studies of YsaN reveal that its activation and oligomerization depend on its N-terminal region and occur as a result of active catalysis of ATP in an ATP concentration-dependent manner following two-step cooperative kinetics. Also, the N-terminal 83 amino acid residues of YsaN are crucial for higher-order oligomer formation while YsaN∆83 is capable of hexamer formation upon oligomerization. Enzyme kinetics study shows reduced ATPase activity of YsaN∆83 (3.19 ± 0.09 μmol/min/mg) in comparison to YsaN (9.076 ± 0.72 μmol/min/mg). Negative-TEM study of YsaN and YsaN∆83 oligomer suggests that the formation of higher-order oligomer (probably dodecamer) occurs by stacking of two hexamers through their N-terminal faces involving N-terminal 83 amino acid residues which have been further supported by the docking of two hexamers during the in-silico study. These results suggest that YsaN is an oligomerization-activated T3SS ATPase, where distinct regions of its N-terminal domain regulate its different oligomeric nature and is essential for its activation.
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Special Issue: Type III Secretion Systems in Human/Animal Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10071461. [PMID: 35889180 PMCID: PMC9319260 DOI: 10.3390/microorganisms10071461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 01/27/2023] Open
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Renoz F, Ambroise J, Bearzatto B, Fakhour S, Parisot N, Ribeiro Lopes M, Gala JL, Calevro F, Hance T. The Di-Symbiotic Systems in the Aphids Sipha maydis and Periphyllus lyropictus Provide a Contrasting Picture of Recent Co-Obligate Nutritional Endosymbiosis in Aphids. Microorganisms 2022; 10:microorganisms10071360. [PMID: 35889078 PMCID: PMC9317480 DOI: 10.3390/microorganisms10071360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/25/2022] Open
Abstract
Dependence on multiple nutritional bacterial symbionts forming a metabolic unit has repeatedly evolved in many insect species that feed on nutritionally unbalanced diets such as plant sap. This is the case for aphids of the subfamilies Lachninae and Chaitophorinae, which have evolved di-symbiotic systems in which the ancient obligate nutritional symbiont Buchnera aphidicola is metabolically complemented by an additional nutritional symbiont acquired more recently. Deciphering how different symbionts integrate both metabolically and anatomically in such systems is crucial to understanding how complex nutritional symbiotic systems function and evolve. In this study, we sequenced and analyzed the genomes of the symbionts B. aphidicola and Serratia symbiotica associated with the Chaitophorinae aphids Sipha maydis and Periphyllus lyropictus. Our results show that, in these two species, B. aphidicola and S. symbiotica complement each other metabolically (and their hosts) for the biosynthesis of essential amino acids and vitamins, but with distinct metabolic reactions supported by each symbiont depending on the host species. Furthermore, the S. symbiotica symbiont associated with S. maydis appears to be strictly compartmentalized into the specialized host cells housing symbionts in aphids, the bacteriocytes, whereas the S. symbiotica symbiont associated with P. lyropictus exhibits a highly invasive phenotype, presumably because it is capable of expressing a larger set of virulence factors, including a complete flagellum for bacterial motility. Such contrasting levels of metabolic and anatomical integration for two S. symbiotica symbionts that were recently acquired as nutritional co-obligate partners reflect distinct coevolutionary processes specific to each association.
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Affiliation(s)
- François Renoz
- Biodiversity Research Centre, Earth and Life Institute, Université Catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium;
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
- Correspondence:
| | - Jérôme Ambroise
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université Catholique de Louvain (UCLouvain), 1200 Woluwe-Saint-Lambert, Belgium; (J.A.); (B.B.); (J.-L.G.)
| | - Bertrand Bearzatto
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université Catholique de Louvain (UCLouvain), 1200 Woluwe-Saint-Lambert, Belgium; (J.A.); (B.B.); (J.-L.G.)
| | - Samir Fakhour
- Department of Plant Protection, National Institute of Agricultural Research, Avenue Ennasr, BP 415 Rabat Principale, Rabat 10090, Morocco;
| | - Nicolas Parisot
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
| | - Mélanie Ribeiro Lopes
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
| | - Jean-Luc Gala
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université Catholique de Louvain (UCLouvain), 1200 Woluwe-Saint-Lambert, Belgium; (J.A.); (B.B.); (J.-L.G.)
| | - Federica Calevro
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
| | - Thierry Hance
- Biodiversity Research Centre, Earth and Life Institute, Université Catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium;
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Mondino S, San Martin F, Buschiazzo A. 3D cryo-electron microscopic imaging of bacterial flagella: novel structural and mechanistic insights into cell motility. J Biol Chem 2022; 298:102105. [PMID: 35671822 PMCID: PMC9254593 DOI: 10.1016/j.jbc.2022.102105] [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] [Received: 01/31/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 10/26/2022] Open
Abstract
Bacterial flagella are nanomachines that enable cells to move at high speeds. Comprising ≳25 different types of proteins, the flagellum is a large supramolecular assembly organized into three widely conserved substructures: a basal body including the rotary motor, a connecting hook, and a long filament. The whole flagellum from Escherichia coli weighs ∼20 MDa, without considering its filament portion, which is by itself a ∼1.6 GDa structure arranged as a multimer of ∼30,000 flagellin protomers. Breakthroughs regarding flagellar structure and function have been achieved in the last few years, mainly due to the revolutionary improvements in 3D cryo-electron microscopy methods. This review discusses novel structures and mechanistic insights derived from such high-resolution studies, advancing our understanding of each one of the three major flagellar segments. The rotation mechanism of the motor has been unveiled with unprecedented detail, showing a two-cogwheel machine propelled by a Brownian ratchet device. Additionally, by imaging the flagellin-like protomers that make up the hook in its native bent configuration, their unexpected conformational plasticity challenges the paradigm of a two-state conformational rearrangement mechanism for flagellin-fold proteins. Finally, imaging of the filaments of periplasmic flagella, which endow Spirochete bacteria with their singular motility style, uncovered a strikingly asymmetric protein sheath that coats the flagellin core, challenging the view of filaments as simple homopolymeric structures that work as freely whirling whips. Further research will shed more light on the functional details of this amazing nanomachine, but our current understanding has definitely come a long way.
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Affiliation(s)
- Sonia Mondino
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay
| | - Fabiana San Martin
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay
| | - Alejandro Buschiazzo
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay; Microbiology Department, Institut Pasteur, Paris, France.
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30
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Filloux A. Bacterial protein secretion systems: Game of types. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35536734 DOI: 10.1099/mic.0.001193] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein trafficking across the bacterial envelope is a process that contributes to the organisation and integrity of the cell. It is the foundation for establishing contact and exchange between the environment and the cytosol. It helps cells to communicate with one another, whether they establish symbiotic or competitive behaviours. It is instrumental for pathogenesis and for bacteria to subvert the host immune response. Understanding the formation of envelope conduits and the manifold strategies employed for moving macromolecules across these channels is a fascinating playground. The diversity of the nanomachines involved in this process logically resulted in an attempt to classify them, which is where the protein secretion system types emerged. As our knowledge grew, so did the number of types, and their rightful nomenclature started to be questioned. While this may seem a semantic or philosophical issue, it also reflects scientific rigour when it comes to assimilating findings into textbooks and science history. Here I give an overview on bacterial protein secretion systems, their history, their nomenclature and why it can be misleading for newcomers in the field. Note that I do not try to suggest a new nomenclature. Instead, I explore the reasons why naming could have escaped our control and I try to reiterate basic concepts that underlie protein trafficking cross membranes.
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Affiliation(s)
- Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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31
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Trivedi A, Gosai J, Nakane D, Shrivastava A. Design Principles of the Rotary Type 9 Secretion System. Front Microbiol 2022; 13:845563. [PMID: 35620107 PMCID: PMC9127263 DOI: 10.3389/fmicb.2022.845563] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/17/2022] [Indexed: 01/05/2023] Open
Abstract
The Fo ATP synthase, the bacterial flagellar motor, and the bacterial type 9 secretion system (T9SS) are the three known proton motive force driven biological rotary motors. In this review, we summarize the current information on the nuts and bolts of T9SS. Torque generation by T9SS, its role in gliding motility of bacteria, and the mechanism via which a T9SS-driven swarm shapes the microbiota are discussed. The knowledge gaps in our current understanding of the T9SS machinery are outlined.
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Affiliation(s)
- Abhishek Trivedi
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, United States
- Center for Biological Physics, Arizona State University, Tempe, AZ, United States
| | - Jitendrapuri Gosai
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, United States
- Center for Biological Physics, Arizona State University, Tempe, AZ, United States
| | - Daisuke Nakane
- Department of Engineering Science, The University of Electro-Communications, Tokyo, Japan
| | - Abhishek Shrivastava
- School of Life Sciences, Arizona State University, Tempe, AZ, United States
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ, United States
- Center for Biological Physics, Arizona State University, Tempe, AZ, United States
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32
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Response of Tomato-Pseudomonas Pathosystem to Mild Heat Stress. HORTICULTURAE 2022. [DOI: 10.3390/horticulturae8020174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Higher plants suffer from mild heat stress when temperatures increase by 5 °C above optimum growth temperatures. This produces changes at the cellular and metabolic levels, allowing plants to adapt to heat conditions. This study investigated an increase of 5 °C above the optimum growth temperature (26 °C) of tomato plants in the tomato–Pseudomonas syringae pv. tomato pathosystem. A temperature increase above 26 °C affects plant development, the defensive pathways activated against Pseudomonas syringae pv. tomato strain DC3000 (PstDC3000), and the bacterial growth and virulence machinery. The results demonstrated that tomato plants were able to acclimate to mild heat stress, showing no symptoms of damage. Moreover, plants subjected to a 5 °C increase (T31 °C plants) showed higher basal levels of metabolites such as proline and putrescine, which probably act as compatible osmolytes. This demonstrates their importance as key components of thermotolerance. When grown under mild heat stress, plants were less susceptible to PstDC3000 and showed increased accumulation of abscisic acid, jasmonic acid-isoleucine, and spermine. In addition, the temperature increase negatively affected the infectivity of PstDC3000. Inhibition of the genes responsible for quorum sensing establishment and synthesis of flagellin and coronatine was observed in bacteria extracted from T31 °C plants. Analysis of the genes involved in the synthesis of the type III secretion system indicates the important role of this system in bacterial growth under these conditions. As the known resistance mechanisms involved in the defense against PstDC3000 were not activated, the changes in its virulence mechanisms under high temperatures may explain the lower infection observed in the T31 °C plants.
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Castro MR, Dias GM, Salles TS, Cabral NM, Mariano DCO, Oliveira HL, Abdelhay ESFW, Binato R, Neves BC. Genome-wide analysis reveals a rhamnolipid-dependent modulation of flagellar genes in Pseudomonas aeruginosa PAO1. Curr Genet 2022; 68:289-304. [DOI: 10.1007/s00294-021-01225-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/28/2021] [Accepted: 12/06/2021] [Indexed: 11/03/2022]
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Shu J, Liu H, Liu Y, Chen X, Yu Y, Lv Q, Wang J, Deng X, Guo Z, Qiu J. Tannic Acid Inhibits Salmonella enterica Serovar Typhimurium Infection by Targeting the Type III Secretion System. Front Microbiol 2022; 12:784926. [PMID: 35145491 PMCID: PMC8822118 DOI: 10.3389/fmicb.2021.784926] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/24/2021] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica serovar Typhimurium (S. Typhimurium) is a zoonotic pathogen that can cause food poisoning and diarrhea in both humans and animals worldwide. The Salmonella pathogenicity island (SPI) genes encoded type III secretion system (T3SS) is important for S. Typhimurium invasion and replication in host cells. Due to the increasing problem of antibiotic resistance, antibiotic treatment for clinical Salmonella infection has gradually been limited. Anti-virulence inhibitors are a promising alternative to antibiotics because they do not easily induce bacterial antibiotic resistance. Here, we systematically evaluated the therapeutic effect of tannic acid (TA) on Salmonella-infected mice and elucidated its anti-infection mechanism. TA treatment improved the survival rate of S. Typhimurium-infected mice and alleviated cecum pathological lesions. In addition, TA inhibited S. Typhimurium invasion to HeLa cells without affecting their growth. Further studies showed that TA could inhibit the expression of sipA and sipB. This inhibition may be implemented by inhibiting the transcription of key regulatory and structural genes of the T3SS. This study provides an alternative anti-virulence strategy for Salmonella infection treatment.
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Affiliation(s)
- Jingyan Shu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Hongtao Liu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yang Liu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xindi Chen
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yu Yu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Qianghua Lv
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jianfeng Wang
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xuming Deng
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Zhimin Guo
- Department of Clinical Laboratory, The First Hospital of Jilin University, Changchun, China
- Zhimin Guo,
| | - Jiazhang Qiu
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
- *Correspondence: Jiazhang Qiu,
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Shem-Tov R, Gal-Mor O. Profiling of Secreted Type 3 Secretion System Substrates by Salmonella enterica. Methods Mol Biol 2022; 2427:47-54. [PMID: 35619024 DOI: 10.1007/978-1-0716-1971-1_5] [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: 06/15/2023]
Abstract
Many of Salmonella enterica virulence-associated phenotypes, including its ability to manipulate various host pathways are mediated by translocation of specific effector proteins via type 3 secretion systems (T3SSs) into the host cell. Culturing Salmonella under a defined set of stimulating conditions in vitro can mimic the physiological signals Salmonella senses during the infection and results in the secretion of these effectors into the growth medium. Here we describe a Salmonella secretion assay to identify and quantify protein substrates secreted by T3SS-1 and demonstrate how this method can be utilized to study the secretion of T3SS-1 effectors and flagellum components in different genetic backgrounds or under varying growth conditions.
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Affiliation(s)
- Rivka Shem-Tov
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- The Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Ohad Gal-Mor
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel.
- The Department of Clinical Microbiology and Immunology, Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel.
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36
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Matilla MA, Velando F, Monteagudo-Cascales E, Krell T. Flagella, Chemotaxis and Surface Sensing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:185-221. [DOI: 10.1007/978-3-031-08491-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Xu J, Wang J, Liu A, Zhang Y, Gao X. Structural and Functional Analysis of SsaV Cytoplasmic Domain and Variable Linker States in the Context of the InvA-SsaV Chimeric Protein. Microbiol Spectr 2021; 9:e0125121. [PMID: 34851139 PMCID: PMC8635156 DOI: 10.1128/spectrum.01251-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/05/2021] [Indexed: 11/20/2022] Open
Abstract
The type III secretion (T3S) injectisome is a syringe-like protein-delivery nanomachine widely utilized by Gram-negative bacteria. It can deliver effector proteins directly from bacteria into eukaryotic host cells, which is crucial for the bacterial-host interaction. Intracellular pathogen Salmonella enterica serovar Typhimurium encodes two sets of T3S injectisomes from Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2), which are critical for its host invasion and intracellular survival, respectively. The inner membrane export gate protein, SctV (InvA in SPI-1 and SsaV in SPI-2), is the largest component of the injectisome and is essential for assembly and function of T3SS. Here, we report the 2.11 Å cryo-EM structure of the SsaV cytoplasmic domain (SsaVC) in the context of a full-length SctV chimera consisting of the transmembrane region of InvA, the linker of SsaV (SsaVL) and SsaVC. The structural analysis shows that SsaVC exists in a semi-open state and SsaVL exhibits two major orientations, implying a highly dynamic process of SsaV for the substrate selection and secretion in a full-length context. A biochemical assay indicates that SsaVL plays an essential role in maintaining the nonameric state of SsaV. This study offers near atomic-level insights into how SsaVC and SsaVL facilitate the assembly and function of SsaV and may lead to the development of potential anti-virulence therapeutics against T3SS-mediated bacterial infection. IMPORTANCE Type III secretion system (T3SS) is a multicomponent nanomachine and a critical virulence factor for a wide range of Gram-negative bacterial pathogens. It can deliver numbers of effectors into the host cell to facilitate the bacterial host infection. Export gate protein SctV, as one of the engines of T3SS, is at the center of T3SS assembly and function. In this study, we show the high-resolution atomic structure of the cytosolic domain of SctV in the nonameric state with variable linker conformations. Our first observation of conformational changes of the linker region of SctV and the semi-open state of the cytosolic domain of SctV in the full-length context further support that the substrate selection and secretion process of SctV is highly dynamic. These findings have important implications for the development of therapeutic strategies targeting SctV to combat T3SS-mediated bacterial infection.
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Affiliation(s)
- Jinghua Xu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jiuqing Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Aijun Liu
- Shanghai Fifth People's Hospital and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yanqing Zhang
- Shanghai Fifth People's Hospital and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xiang Gao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
- School of Life Sciences, Shandong University, Qingdao, China
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Rahmatelahi H, El-Matbouli M, Menanteau-Ledouble S. Delivering the pain: an overview of the type III secretion system with special consideration for aquatic pathogens. Vet Res 2021; 52:146. [PMID: 34924019 PMCID: PMC8684695 DOI: 10.1186/s13567-021-01015-8] [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: 07/15/2021] [Accepted: 11/08/2021] [Indexed: 11/10/2022] Open
Abstract
Gram-negative bacteria are known to subvert eukaryotic cell physiological mechanisms using a wide array of virulence factors, among which the type three-secretion system (T3SS) is often one of the most important. The T3SS constitutes a needle-like apparatus that the bacterium uses to inject a diverse set of effector proteins directly into the cytoplasm of the host cells where they can hamper the host cellular machinery for a variety of purposes. While the structure of the T3SS is somewhat conserved and well described, effector proteins are much more diverse and specific for each pathogen. The T3SS can remodel the cytoskeleton integrity to promote intracellular invasion, as well as silence specific eukaryotic cell signals, notably to hinder or elude the immune response and cause apoptosis. This is also the case in aquatic bacterial pathogens where the T3SS can often play a central role in the establishment of disease, although it remains understudied in several species of important fish pathogens, notably in Yersinia ruckeri. In the present review, we summarise what is known of the T3SS, with a special focus on aquatic pathogens and suggest some possible avenues for research including the potential to target the T3SS for the development of new anti-virulence drugs.
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Affiliation(s)
- Hadis Rahmatelahi
- Clinical Division of Fish Medicine, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Simon Menanteau-Ledouble
- Clinical Division of Fish Medicine, University of Veterinary Medicine, 1210, Vienna, Austria.
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220, Aalborg Ø, Denmark.
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Wu HP, Derilo RC, Chen HL, Li TR, Lagitnay RBJS, Chan YC, Chuang Y, Chuang DY. Injectisome T3SS subunits as potential chaperones in the extracellular export of Pectobacterium carotovorum subsp. carotovorum bacteriocins Carocin S1 and Carocin S3 secreted via flagellar T3SS. BMC Microbiol 2021; 21:345. [PMID: 34911446 PMCID: PMC8672553 DOI: 10.1186/s12866-021-02405-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/26/2021] [Indexed: 12/27/2022] Open
Abstract
Pectobacterium carotovorum subsp. carotovorum (Pcc) causes soft-rot disease in a wide variety of plants resulting in economic losses worldwide. It produces various types of bacteriocin to compete against related plant pathogens. Studies on how bacteriocins are extracellularly secreted are conducted to understand the mechanism of interbacterial competition. In this study, the secretion of the low-molecular-weight bacteriocins (LMWB) Carocin S1 and Carocin S3 produced by a multiple-bacteriocin producing strain of Pcc, 89-H-4, was investigated. Tn5 insertional mutagenesis was used to generate a mutant, TH22–6, incapable of LMWBs secretion. Sequence and homology analyses of the gene disrupted by transposon Tn5 insertion revealed that the gene sctT, an essential component of the injectisome type III secretion machinery (T3aSS), is required for the secretion of the bacteriocins. This result raised a question regarding the nature of the secretion mechanism of Pcc bacteriocins which was previously discovered to be secreted via T3bSS, a system that utilizes the bacterial flagellum for extracellular secretions. Our previous report has shown that bacteriocin Carocin S1 cannot be secreted by mutants that are defective of T3bSS-related genes such as flhA, flhC, flhD and fliC. We knocked out several genes making up the significant structural components of both T3aSS and T3bSS. The findings led us to hypothesize the potential roles of the T3aSS-related proteins, SctT, SctU and SctV, as flagellar T3SS chaperones in the secretion of Pcc bacteriocins. This current discovery and the findings of our previous study helped us to conceptualize a unique Type III secretion system for bacteriocin extracellular export which is a hybrid of the injectisome and flagellar secretion systems.
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Affiliation(s)
- Huang-Pin Wu
- Division of Pulmonary, Critical Care and Sleep Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Reymund C Derilo
- Department of Chemistry, National Chung Hsing University, 145, Xingda Rd., Taichung, 402, Taiwan.,College of Teacher Education, Nueva Vizcaya State University Bambang Campus, Bambang, Nueva Vizcaya, Philippines
| | - Han-Ling Chen
- Department of Chemistry, National Chung Hsing University, 145, Xingda Rd., Taichung, 402, Taiwan
| | - Tzu-Rung Li
- Department of Chemistry, National Chung Hsing University, 145, Xingda Rd., Taichung, 402, Taiwan
| | - Ruchi Briam James S Lagitnay
- Department of Chemistry, National Chung Hsing University, 145, Xingda Rd., Taichung, 402, Taiwan.,College of Arts and Sciences, Nueva Vizcaya State University Bayombong Campus, Bayombong, Nueva Vizcaya, Philippines
| | - Yung-Chieh Chan
- Department of Chemistry, National Chung Hsing University, 145, Xingda Rd., Taichung, 402, Taiwan
| | - Yutin Chuang
- Department of Entomology, National Chung Hsing University, Taichung City, Taiwan
| | - Duen-Yau Chuang
- Department of Chemistry, National Chung Hsing University, 145, Xingda Rd., Taichung, 402, Taiwan.
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40
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Cai D, Brickey WJ, Ting JP, Sad S. Isolates of Salmonella typhimurium circumvent NLRP3 inflammasome recognition in macrophages during the chronic phase of infection. J Biol Chem 2021; 298:101461. [PMID: 34864057 PMCID: PMC8715120 DOI: 10.1016/j.jbc.2021.101461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 11/25/2021] [Accepted: 11/29/2021] [Indexed: 11/27/2022] Open
Abstract
Inflammasome signaling results in cell death and release of cytokines from the IL-1 family, which facilitates control over an infection. However, some pathogens such as Salmonella typhimurium (ST) activate various innate immune signaling pathways, including inflammasomes, yet evade these cell death mechanisms, resulting in a chronic infection. Here we investigated inflammasome signaling induced by acute and chronic isolates of ST obtained from different organs. We show that ST isolated from infected mice during the acute phase displays an increased potential to activate inflammasome signaling, which then undergoes a protracted decline during the chronic phase of infection. This decline in inflammasome signaling was associated with reduced expression of virulence factors, including flagella and the Salmonella pathogenicity island I genes. This reduction in cell death of macrophages induced by chronic isolates had the greatest impact on the NLRP3 inflammasome, which correlated with a reduction in caspase-1 activation. Furthermore, rapid cell death induced by Casp-1/11 by ST in macrophages limited the subsequent activation of cell death cascade proteins Casp-8, RipK1, RipK3, and MLKL to prevent the activation of alternative forms of cell death. We observed that the lack of the ability to induce cell death conferred a competitive fitness advantage to ST only during the acute phase of infection. Finally, we show that the chronic isolates displayed a significant attenuation in their ability to infect mice through the oral route. These results reveal that ST adapts during chronic infection by circumventing inflammasome recognition to promote the survival of both the host and the pathogen.
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Affiliation(s)
- David Cai
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Willie June Brickey
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jenny P Ting
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Subash Sad
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Centre for Infection, Immunity, and Inflammation (CI3), University of Ottawa, Ottawa, Ontario, Canada.
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41
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Identification of Translocation Inhibitors Targeting the Type III Secretion System of Enteropathogenic Escherichia coli. Antimicrob Agents Chemother 2021; 65:e0095821. [PMID: 34543097 DOI: 10.1128/aac.00958-21] [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: 11/20/2022] Open
Abstract
Infections with enteropathogenic Escherichia coli (EPEC) cause severe diarrhea in children. The noninvasive bacteria adhere to enterocytes of the small intestine and use a type III secretion system (T3SS) to inject effector proteins into host cells to modify and exploit cellular processes in favor of bacterial survival and replication. Several studies have shown that the T3SSs of bacterial pathogens are essential for virulence. Furthermore, the loss of T3SS-mediated effector translocation results in increased immune recognition and clearance of the bacteria. The T3SS is, therefore, considered a promising target for antivirulence strategies and novel therapeutics development. Here, we report the results of a high-throughput screening assay based on the translocation of the EPEC effector protein Tir (translocated intimin receptor). Using this assay, we screened more than 13,000 small molecular compounds of six different compound libraries and identified three substances which showed a significant dose-dependent effect on translocation without adverse effects on bacterial or eukaryotic cell viability. In addition, these substances reduced bacterial binding to host cells, effector-dependent cell detachment, and abolished attaching and effacing lesion formation without affecting the expression of components of the T3SS or associated effector proteins. Moreover, no effects of the inhibitors on bacterial motility or Shiga-toxin expression were observed. In summary, we have identified three new compounds that strongly inhibit T3SS-mediated translocation of effectors into mammalian cells, which could be valuable as lead substances for treating EPEC and enterohemorrhagic E. coli infections.
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42
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Biswas S, Wu C, van der Donk WA. The Antimicrobial Activity of the Glycocin Sublancin Is Dependent on an Active Phosphoenolpyruvate-Sugar Phosphotransferase System. ACS Infect Dis 2021; 7:2402-2412. [PMID: 34242010 DOI: 10.1021/acsinfecdis.1c00157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Antimicrobial resistance is a global challenge that is compounded by the limited number of available targets. Glycocins are antimicrobial glycopeptides that are believed to have novel targets. Previous studies have shown that the mechanism of action of the glycocin sublancin 168 involves the glucose uptake system. The phosphoenolpyruvate:sugar phosphotransferase system (PTS) phosphorylates the C6 hydroxyl group on glucose during import. Since sublancin carries a glucose on a Cys on an exposed loop, we investigated whether phosphorylation of this glucose might be involved in its mechanism of action by replacement with xylose. Surprisingly, the xylose analog was more active than wild-type sublancin and still required the glucose PTS for activity. Overexpression of the individual components of the PTS rendered cells more sensitive to sublancin, and their resistance frequency was considerably decreased. These observations suggest that sublancin is activated in some form by the glucose PTS or that sublancin imparts a deleterious gain-of-function on the PTS. Superresolution microscopy studies with fluorescent sublancin and fluorescently labeled PTS proteins revealed localization of both at the poles of cells. Resistant mutants raised under conditions that would minimize mutation of the PTS revealed mutations in FliQ, a protein involved in the flagellar protein export process. Overexpression of FliQ lead to decreased sensitivity of cells to sublancin. Collectively, these findings enforce a model in which the PTS is required for sublancin activity, either by inducing a deleterious gain-of-function or by activating or transporting sublancin.
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43
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Structure of the molecular bushing of the bacterial flagellar motor. Nat Commun 2021; 12:4469. [PMID: 34294704 PMCID: PMC8298488 DOI: 10.1038/s41467-021-24715-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 06/29/2021] [Indexed: 12/15/2022] Open
Abstract
The basal body of the bacterial flagellum is a rotary motor that consists of several rings (C, MS and LP) and a rod. The LP ring acts as a bushing supporting the distal rod for its rapid and stable rotation without much friction. Here, we use electron cryomicroscopy to describe the LP ring structure around the rod, at 3.5 Å resolution, from Salmonella Typhimurium. The structure shows 26-fold rotational symmetry and intricate intersubunit interactions of each subunit with up to six partners, which explains the structural stability. The inner surface is charged both positively and negatively. Positive charges on the P ring (the part of the LP ring that is embedded within the peptidoglycan layer) presumably play important roles in its initial assembly around the rod with a negatively charged surface. In the basal body of the bacterial flagellum, the LP ring acts as a bushing supporting the distal rod for its rapid and stable rotation. Here, Yamaguchi et al. present the electron cryomicroscopy structure of the LP ring around the rod, shedding light into potential mechanisms involved in stability and assembly of the structure.
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44
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Dynamic Adaptive Response of Pseudomonas aeruginosa to Clindamycin/Rifampicin-Impregnated Catheters. Antibiotics (Basel) 2021; 10:antibiotics10070752. [PMID: 34206280 PMCID: PMC8300626 DOI: 10.3390/antibiotics10070752] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
Pseudomonas aeruginosa is the most common Gram-negative pathogen causing nosocomial multidrug resistant infections. It is a good biofilm producer and has the potential for contaminating medical devices. Despite the widespread use of antibacterial-impregnated catheters, little is known about the impacts of antibacterial coating on the pathogenesis of P. aeruginosa. In this study, we investigated the adaptive resistance potential of P. aeruginosa strain PAO1 in response to continuous antibiotic exposure from clindamycin/rifampicin-impregnated catheters (CR-IC). During exposure for 144 h to clindamycin and rifampicin released from CR-IC, strain PAO1 formed biofilms featuring elongated and swollen cells. There were 545 and 372 differentially expressed proteins (DEPs) identified in the planktonic and biofilm cells, respectively, by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Both Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the planktonic cells responded to the released antibiotics more actively than the biofilm cells, with metabolism and ribosomal biosynthesis-associated proteins being significantly over-expressed. Exposure to CR-IC increased the invasion capability of P. aeruginosa for Hela cells and upregulated the expression of certain groups of virulence proteins in both planktonic and biofilm cells, including the outer membrane associated (flagella, type IV pili and type III secretion system) and extracellular (pyoverdine) virulence proteins. Continuous exposure of P. aeruginosa to CR-IC also induced the overexpression of antibiotic resistance proteins, including porins, efflux pumps, translation and transcription proteins. However, these upregulations did not change phenotypic minimum inhibitory concentration (MIC) during the experimental timeframe. The concerning association between CR-IC and overexpression of virulence factors in P. aeruginosa suggests the need for additional investigation to determine if it results in adverse clinical outcomes.
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45
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Developing Cyclic Peptomers as Broad-Spectrum Type III Secretion System Inhibitors in Gram-Negative Bacteria. Antimicrob Agents Chemother 2021; 65:e0169020. [PMID: 33875435 PMCID: PMC8373237 DOI: 10.1128/aac.01690-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Antibiotic-resistant bacteria are an emerging global health threat. New antimicrobials are urgently needed. The injectisome type III secretion system (T3SS), required by dozens of Gram-negative bacteria for virulence but largely absent from nonpathogenic bacteria, is an attractive antimicrobial target. We previously identified synthetic cyclic peptomers, inspired by the natural product phepropeptin D, that inhibit protein secretion through the Yersinia Ysc and Pseudomonas aeruginosa Psc T3SSs but do not inhibit bacterial growth. Here, we describe the identification of an isomer, 4EpDN, that is 2-fold more potent (50% inhibitory concentration [IC50] of 4 μM) than its parental compound. Furthermore, 4EpDN inhibited the Yersinia Ysa and the Salmonella SPI-1 T3SSs, suggesting that this cyclic peptomer has broad efficacy against evolutionarily distant injectisome T3SSs. Indeed, 4EpDN strongly inhibited intracellular growth of Chlamydia trachomatis in HeLa cells, which requires the T3SS. 4EpDN did not inhibit the unrelated twin arginine translocation (Tat) system, nor did it impact T3SS gene transcription. Moreover, although the injectisome and flagellar T3SSs are evolutionarily and structurally related, the 4EpDN cyclic peptomer did not inhibit secretion of substrates through the Salmonella flagellar T3SS, indicating that cyclic peptomers broadly but specifically target the injectisome T3SS. 4EpDN reduced the number of T3SS needles detected on the surface of Yersinia pseudotuberculosis as detected by microscopy. Collectively, these data suggest that cyclic peptomers specifically inhibit the injectisome T3SS from a variety of Gram-negative bacteria, possibly by preventing complete T3SS assembly.
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46
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Abstract
The bacterial flagellar motor is a complex macromolecular machine whose function and self-assembly present a fascinating puzzle for structural biologists. Here, we report that in diverse bacterial species, cell lysis leads to loss of the cytoplasmic switch complex and associated ATPase before other components of the motor. This loss may be prevented by the formation of a cytoplasmic vesicle around the complex. These observations suggest a relatively loose association of the switch complex with the rest of the flagellar machinery. IMPORTANCE We show in eight different bacterial species (belonging to different phyla) that the flagellar motor loses its cytoplasmic switch complex upon cell lysis, while the rest of the flagellum remains attached to the cell body. This suggests an evolutionary conserved weak interaction between the switch complex and the rest of the flagellum which is important to understand how the motor evolved. In addition, this information is crucial for mimicking such nanomachines in the laboratory.
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47
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Hajra D, Nair AV, Chakravortty D. An elegant nano-injection machinery for sabotaging the host: Role of Type III secretion system in virulence of different human and animal pathogenic bacteria. Phys Life Rev 2021; 38:25-54. [PMID: 34090822 DOI: 10.1016/j.plrev.2021.05.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 05/23/2021] [Indexed: 01/22/2023]
Abstract
Various Gram-negative bacteria possess a specialized membrane-bound protein secretion system known as the Type III secretion system (T3SS), which transports the bacterial effector proteins into the host cytosol thereby helping in bacterial pathogenesis. The T3SS has a special needle-like translocon that can sense the contact with the host cell membrane and translocate effectors. The export apparatus of T3SS recognizes these effector proteins bound to chaperones and translocates them into the host cell. Once in the host cell cytoplasm, these effector proteins result in modulation of the host system and promote bacterial localization and infection. Using molecular biology, bioinformatics, genetic techniques, electron microscopic studies, and mathematical modeling, the structure and function of the T3SS and the corresponding effector proteins in various bacteria have been studied. The strategies used by different human pathogenic bacteria to modulate the host system and thereby enhance their virulence mechanism using T3SS have also been well studied. Here we review the history, evolution, and general structure of the T3SS, highlighting the details of its comparison with the flagellar export machinery. Also, this article provides mechanistic details about the common role of T3SS in subversion and manipulation of host cellular processes. Additionally, this review describes specific T3SS apparatus and the role of their specific effectors in bacterial pathogenesis by considering several human and animal pathogenic bacteria.
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Affiliation(s)
- Dipasree Hajra
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
| | - Abhilash Vijay Nair
- Department of Microbiology & Cell Biology, Indian Institute of Science, India
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48
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Matzke NJ, Lin A, Stone M, Baker MAB. Flagellar export apparatus and ATP synthetase: Homology evidenced by synteny predating the Last Universal Common Ancestor. Bioessays 2021; 43:e2100004. [PMID: 33998015 DOI: 10.1002/bies.202100004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 04/01/2021] [Accepted: 04/21/2021] [Indexed: 11/07/2022]
Abstract
We report evidence further supporting homology between proteins in the F1 FO -ATP synthetase and the bacterial flagellar motor (BFM). BFM proteins FliH, FliI, and FliJ have been hypothesized to be homologous to FO -b + F1 -δ, F1 -α/β, and F1 -γ, with similar structure and interactions. We conduct a further test by constructing a gene order dataset, examining the order of fliH, fliI, and fliJ genes across the phylogenetic breadth of flagellar and nonflagellar type 3 secretion systems, and comparing this to published surveys of gene order in the F1 FO -ATP synthetase, its N-ATPase relatives, and the bacterial/archaeal V- and A-type ATPases. Strikingly, the fliHIJ gene order was deeply conserved, with the few exceptions appearing derived, and exactly matching the widely conserved F-ATPase gene order atpFHAG, coding for subunits b-δ-α-γ. The V/A-type ATPases have a similar conserved gene order. Our results confirm homology between these systems, and suggest a rare case of synteny conserved over billions of years, predating the Last Universal Common Ancestor (LUCA).
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Affiliation(s)
- Nicholas J Matzke
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Angela Lin
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Micaella Stone
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Matthew A B Baker
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia.,CSIRO Synthetic Biology Future Science Platform, Brisbane, Australia
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49
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CesL Regulates Type III Secretion Substrate Specificity of the Enteropathogenic E. coli Injectisome. Microorganisms 2021; 9:microorganisms9051047. [PMID: 34067942 PMCID: PMC8152094 DOI: 10.3390/microorganisms9051047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 11/23/2022] Open
Abstract
The type III secretion system (T3SS) is a complex molecular device used by several pathogenic bacteria to translocate effector proteins directly into eukaryotic host cells. One remarkable feature of the T3SS is its ability to secrete different categories of proteins in a hierarchical manner, to ensure proper assembly and timely delivery of effectors into target cells. In enteropathogenic Escherichia coli, the substrate specificity switch from translocator to effector secretion is regulated by a gatekeeper complex composed of SepL, SepD, and CesL proteins. Here, we report a characterization of the CesL protein using biochemical and genetic approaches. We investigated discrepancies in the phenotype among different cesL deletion mutants and showed that CesL is indeed essential for translocator secretion and to prevent premature effector secretion. We also demonstrated that CesL engages in pairwise interactions with both SepL and SepD. Furthermore, while association of SepL to the membrane does not depended on CesL, the absence of any of the proteins forming the heterotrimeric complex compromised the intracellular stability of each component. In addition, we found that CesL interacts with the cytoplasmic domains of the export gate components EscU and EscV. We propose a mechanism for substrate secretion regulation governed by the SepL/SepD/CesL complex.
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50
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Wang Y, Zhou M, Zou Q, Xu L. Machine learning for phytopathology: from the molecular scale towards the network scale. Brief Bioinform 2021; 22:6204793. [PMID: 33787847 DOI: 10.1093/bib/bbab037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/09/2021] [Accepted: 01/26/2021] [Indexed: 01/16/2023] Open
Abstract
With the increasing volume of high-throughput sequencing data from a variety of omics techniques in the field of plant-pathogen interactions, sorting, retrieving, processing and visualizing biological information have become a great challenge. Within the explosion of data, machine learning offers powerful tools to process these complex omics data by various algorithms, such as Bayesian reasoning, support vector machine and random forest. Here, we introduce the basic frameworks of machine learning in dissecting plant-pathogen interactions and discuss the applications and advances of machine learning in plant-pathogen interactions from molecular to network biology, including the prediction of pathogen effectors, plant disease resistance protein monitoring and the discovery of protein-protein networks. The aim of this review is to provide a summary of advances in plant defense and pathogen infection and to indicate the important developments of machine learning in phytopathology.
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Affiliation(s)
- Yansu Wang
- Postdoctoral Innovation Practice Base, Shenzhen Polytechnic, China
| | | | - Quan Zou
- University of Electronic Science and Technology of China
| | - Lei Xu
- Shenzhen Polytechnic, China
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