251
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Kumar H, Ananthanarayanan V. Friend or Foe? The Role of the Host Cytoskeleton in Cellular Responses to Bacterial Pore Forming Toxins. J Indian Inst Sci 2021. [DOI: 10.1007/s41745-020-00218-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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252
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Abstract
Membrane protein pores have demonstrated applications in nanopore technology. Previous studies have mostly focused on β-barrel protein pores, whereas α-helix-based transmembrane protein pores are rarely explored in nanopore applications. Here, we developed a synthetic transmembrane peptide pore built entirely from short synthetic α-helical peptides. We examined the formation of a stable uniform ion-selective pore in single-channel electrical recordings. Furthermore, we show that cyclodextrins (CDs) block the peptide pores and determine the kinetics of CD binding and translocation. We suggest that such designed synthetic transmembrane pores will be useful for several applications in biotechnology, including stochastic sensing.
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253
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Pore-forming proteins: From defense factors to endogenous executors of cell death. Chem Phys Lipids 2020; 234:105026. [PMID: 33309552 DOI: 10.1016/j.chemphyslip.2020.105026] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023]
Abstract
Pore-forming proteins (PFPs) and small antimicrobial peptides (AMPs) represent a large family of molecules with the common ability to punch holes in cell membranes to alter their permeability. They play a fundamental role as infectious bacteria's defensive tools against host's immune system and as executors of endogenous machineries of regulated cell death in eukaryotic cells. Despite being highly divergent in primary sequence and 3D structure, specific folds of pore-forming domains have been conserved. In fact, pore formation is considered an ancient mechanism that takes place through a general multistep process involving: membrane partitioning and insertion, oligomerization and pore formation. However, different PFPs and AMPs assemble and form pores following different mechanisms that could end up either in the formation of protein-lined or protein-lipid pores. In this review, we analyze the current findings in the mechanism of action of different PFPs and AMPs that support a wide role of membrane pore formation in nature. We also provide the newest insights into the development of state-of-art techniques that have facilitated the characterization of membrane pores. To understand the physiological role of these peptides/proteins or develop clinical applications, it is essential to uncover the molecular mechanism of how they perforate membranes.
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254
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Vita GM, De Simone G, Leboffe L, Montagnani F, Mariotti D, Di Bella S, Luzzati R, Gori A, Ascenzi P, di Masi A. Human Serum Albumin Binds Streptolysin O (SLO) Toxin Produced by Group A Streptococcus and Inhibits Its Cytotoxic and Hemolytic Effects. Front Immunol 2020; 11:507092. [PMID: 33363530 PMCID: PMC7752801 DOI: 10.3389/fimmu.2020.507092] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 10/20/2020] [Indexed: 12/14/2022] Open
Abstract
The pathogenicity of group A Streptococcus (GAS) is mediated by direct bacterial invasivity and toxin-associated damage. Among the extracellular products, the exotoxin streptolysin O (SLO) is produced by almost all GAS strains. SLO is a pore forming toxin (PFT) hemolitically active and extremely toxic in vivo. Recent evidence suggests that human serum albumin (HSA), the most abundant protein in plasma, is a player in the innate immunity "orchestra." We previously demonstrated that HSA acts as a physiological buffer, partially neutralizing Clostridioides difficile toxins that reach the bloodstream after being produced in the colon. Here, we report the in vitro and ex vivo capability of HSA to neutralize the cytotoxic and hemolytic effects of SLO. HSA binds SLO with high affinity at a non-conventional site located in domain II, which was previously reported to interact also with C. difficile toxins. HSA:SLO recognition protects HEp-2 and A549 cells from cytotoxic effects and cell membrane permeabilization induced by SLO. Moreover, HSA inhibits the SLO-dependent hemolytic effect in red blood cells isolated from healthy human donors. The recognition of SLO by HSA may have a significant protective role in human serum and sustains the emerging hypothesis that HSA is an important constituent of the innate immunity system.
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Affiliation(s)
| | | | - Loris Leboffe
- Department of Sciences, Roma Tre University, Roma, Italy
| | - Francesca Montagnani
- Department of Medical Biotechnologies, University of Siena, Siena, Italy.,Infectious and Tropical Diseases Unit, Department of Medical Sciences, Hospital of Siena, Siena, Italy
| | | | - Stefano Di Bella
- Infectious Diseases Unit, Clinical Department of Medical, Siurgical, and Health Sciences, University of Trieste, Trieste, Italy
| | - Roberto Luzzati
- Infectious Diseases Unit, Clinical Department of Medical, Siurgical, and Health Sciences, University of Trieste, Trieste, Italy
| | - Andrea Gori
- Infectious Diseases Unit, Department of Internal Medicine, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Centre for Multidisciplinary Research in Health Science (MACH), University of Milan, Milan, Italy
| | - Paolo Ascenzi
- Department of Sciences, Roma Tre University, Roma, Italy
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255
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Cao C, Krapp LF, Al Ouahabi A, König NF, Cirauqui N, Radenovic A, Lutz JF, Peraro MD. Aerolysin nanopores decode digital information stored in tailored macromolecular analytes. SCIENCE ADVANCES 2020; 6:eabc2661. [PMID: 33298438 PMCID: PMC7725454 DOI: 10.1126/sciadv.abc2661] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 10/26/2020] [Indexed: 05/23/2023]
Abstract
Digital data storage is a growing need for our society and finding alternative solutions than those based on silicon or magnetic tapes is a challenge in the era of "big data." The recent development of polymers that can store information at the molecular level has opened up new opportunities for ultrahigh density data storage, long-term archival, anticounterfeiting systems, and molecular cryptography. However, synthetic informational polymers are so far only deciphered by tandem mass spectrometry. In comparison, nanopore technology can be faster, cheaper, nondestructive and provide detection at the single-molecule level; moreover, it can be massively parallelized and miniaturized in portable devices. Here, we demonstrate the ability of engineered aerolysin nanopores to accurately read, with single-bit resolution, the digital information encoded in tailored informational polymers alone and in mixed samples, without compromising information density. These findings open promising possibilities to develop writing-reading technologies to process digital data using a biological-inspired platform.
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Affiliation(s)
- Chan Cao
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Lucien F Krapp
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Abdelaziz Al Ouahabi
- Université de Strasbourg, Centre national de la recherche scientifique (CNRS), Institute Charles Sadron UPR22, 23 rue du Loess, 67034 Strasbourg Cedex 2, France
| | - Niklas F König
- Université de Strasbourg, Centre national de la recherche scientifique (CNRS), Institute Charles Sadron UPR22, 23 rue du Loess, 67034 Strasbourg Cedex 2, France
| | - Nuria Cirauqui
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Department of Pharmaceutical Biotechnology, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
- CNRS, UMR5086, "Molecular Microbiology and Structural Biochemistry", University of Lyon, 7 Passage du Vercors, 69367 Lyon, France
| | - Aleksandra Radenovic
- Institute of Bioengineering, School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
| | - Jean-François Lutz
- Université de Strasbourg, Centre national de la recherche scientifique (CNRS), Institute Charles Sadron UPR22, 23 rue du Loess, 67034 Strasbourg Cedex 2, France.
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
- Swiss Institute of Bioinformatics (SIB), 1015 Lausanne, Switzerland
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256
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Ito Y, Osaki T, Kamiya K, Yamada T, Miki N, Takeuchi S. Rapid and Resilient Detection of Toxin Pore Formation Using a Lipid Bilayer Array. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2005550. [PMID: 33191570 DOI: 10.1002/smll.202005550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/14/2020] [Indexed: 06/11/2023]
Abstract
An artificial cell membrane is applied to study the pore formation mechanisms of bacterial pore-forming toxins for therapeutic applications. Electrical monitoring of ionic current across the membrane provides information on the pore formation process of toxins at the single pore level, as well as the pore characteristics such as dimensions and ionic selectivity. However, the efficiency of pore formation detection largely depends on the encounter probability of toxin to the membrane and the fragility of the membrane. This study presents a bilayer lipid membrane array that parallelizes 4 or 16 sets of sensing elements composed of pairs of a membrane and a series electrical resistor. The series resistor prevents current overflow attributed to membrane rupture, and enables current monitoring of the parallelized membranes with a single detector. The array system shortens detection time of a pore-forming protein and improves temporal stability. The current signature represents the states of pore formation and rupture at respective membranes. The developed system will help in understanding the toxic activity of pore-forming toxins.
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Affiliation(s)
- Yoshihisa Ito
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
- Center for Multidisciplinary and Design Science, School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Toshihisa Osaki
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Koki Kamiya
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
| | - Tetsuya Yamada
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
| | - Norihisa Miki
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
- Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Shoji Takeuchi
- Artificial Cell Membrane Systems Group, Kanagawa Institute of Industrial Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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257
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Flores‐Romero H, Ros U, Garcia‐Saez AJ. Pore formation in regulated cell death. EMBO J 2020; 39:e105753. [PMID: 33124082 PMCID: PMC7705454 DOI: 10.15252/embj.2020105753] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/13/2020] [Accepted: 10/06/2020] [Indexed: 12/21/2022] Open
Abstract
The discovery of alternative signaling pathways that regulate cell death has revealed multiple strategies for promoting cell death with diverse consequences at the tissue and organism level. Despite the divergence in the molecular components involved, membrane permeabilization is a common theme in the execution of regulated cell death. In apoptosis, the permeabilization of the outer mitochondrial membrane by BAX and BAK releases apoptotic factors that initiate the caspase cascade and is considered the point of no return in cell death commitment. Pyroptosis and necroptosis also require the perforation of the plasma membrane at the execution step, which involves Gasdermins in pyroptosis, and MLKL in the case of necroptosis. Although BAX/BAK, Gasdermins and MLKL share certain molecular features like oligomerization, they form pores in different cellular membranes via distinct mechanisms. Here, we compare and contrast how BAX/BAK, Gasdermins, and MLKL alter membrane permeability from a structural and biophysical perspective and discuss the general principles of membrane permeabilization in the execution of regulated cell death.
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Affiliation(s)
- Hector Flores‐Romero
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Uris Ros
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Ana J Garcia‐Saez
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
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258
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Functional and Structural Variation among Sticholysins, Pore-Forming Proteins from the Sea Anemone Stichodactyla helianthus. Int J Mol Sci 2020; 21:ijms21238915. [PMID: 33255441 PMCID: PMC7727798 DOI: 10.3390/ijms21238915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/15/2022] Open
Abstract
Venoms constitute complex mixtures of many different molecules arising from evolution in processes driven by continuous prey-predator interactions. One of the most common compounds in these venomous cocktails are pore-forming proteins, a family of toxins whose activity relies on the disruption of the plasmatic membranes by forming pores. The venom of sea anemones, belonging to the oldest lineage of venomous animals, contains a large amount of a characteristic group of pore-forming proteins known as actinoporins. They bind specifically to sphingomyelin-containing membranes and suffer a conformational metamorphosis that drives them to make pores. This event usually leads cells to death by osmotic shock. Sticholysins are the actinoporins produced by Stichodactyla helianthus. Three different isotoxins are known: Sticholysins I, II, and III. They share very similar amino acid sequence and three-dimensional structure but display different behavior in terms of lytic activity and ability to interact with cholesterol, an important lipid component of vertebrate membranes. In addition, sticholysins can act in synergy when exerting their toxin action. The subtle, but important, molecular nuances that explain their different behavior are described and discussed throughout the text. Improving our knowledge about sticholysins behavior is important for eventually developing them into biotechnological tools.
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259
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Design and Assembly of Transmembrane Helix Barrel. J Membr Biol 2020; 253:491-497. [PMID: 33200236 DOI: 10.1007/s00232-020-00145-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
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260
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Mishima Y, Ishihara S. Molecular Mechanisms of Microbiota-Mediated Pathology in Irritable Bowel Syndrome. Int J Mol Sci 2020; 21:ijms21228664. [PMID: 33212919 PMCID: PMC7698457 DOI: 10.3390/ijms21228664] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 02/07/2023] Open
Abstract
Irritable bowel syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders, and accumulating evidence gained in both preclinical and clinical studies indicate the involvement of enteric microbiota in its pathogenesis. Gut resident microbiota appear to influence brain activity through the enteric nervous system, while their composition and function are affected by the central nervous system. Based on these results, the term “brain–gut–microbiome axis” has been proposed and enteric microbiota have become a potential therapeutic target in IBS cases. However, details regarding the microbe-related pathophysiology of IBS remain elusive. This review summarizes the existing knowledge of molecular mechanisms in the pathogenesis of IBS as well as recent progress related to microbiome-derived neurotransmitters, compounds, metabolites, neuroendocrine factors, and enzymes.
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261
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Shah NR, Voisin TB, Parsons ES, Boyd CM, Hoogenboom BW, Bubeck D. Structural basis for tuning activity and membrane specificity of bacterial cytolysins. Nat Commun 2020; 11:5818. [PMID: 33199689 PMCID: PMC7669874 DOI: 10.1038/s41467-020-19482-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/14/2020] [Indexed: 11/25/2022] Open
Abstract
Cholesterol-dependent cytolysins (CDCs) are pore-forming proteins that serve as major virulence factors for pathogenic bacteria. They target eukaryotic cells using different mechanisms, but all require the presence of cholesterol to pierce lipid bilayers. How CDCs use cholesterol to selectively lyse cells is essential for understanding virulence strategies of several pathogenic bacteria, and for repurposing CDCs to kill new cellular targets. Here we address that question by trapping an early state of pore formation for the CDC intermedilysin, bound to the human immune receptor CD59 in a nanodisc model membrane. Our cryo electron microscopy map reveals structural transitions required for oligomerization, which include the lateral movement of a key amphipathic helix. We demonstrate that the charge of this helix is crucial for tuning lytic activity of CDCs. Furthermore, we discover modifications that overcome the requirement of cholesterol for membrane rupture, which may facilitate engineering the target-cell specificity of pore-forming proteins.
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Affiliation(s)
- Nita R Shah
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, UK
| | - Tomas B Voisin
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, UK
| | - Edward S Parsons
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK
| | - Courtney M Boyd
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, UK
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London, WC1H 0AH, UK
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - Doryen Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London, SW7 2AZ, UK.
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262
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Krawczyk PA, Laub M, Kozik P. To Kill But Not Be Killed: Controlling the Activity of Mammalian Pore-Forming Proteins. Front Immunol 2020; 11:601405. [PMID: 33281828 PMCID: PMC7691655 DOI: 10.3389/fimmu.2020.601405] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/20/2020] [Indexed: 01/01/2023] Open
Abstract
Pore-forming proteins (PFPs) are present in all domains of life, and play an important role in host-pathogen warfare and in the elimination of cancers. They can be employed to deliver specific effectors across membranes, to disrupt membrane integrity interfering with cell homeostasis, and to lyse membranes either destroying intracellular organelles or entire cells. Considering the destructive potential of PFPs, it is perhaps not surprising that mechanisms controlling their activity are remarkably complex, especially in multicellular organisms. Mammalian PFPs discovered to date include the complement membrane attack complex (MAC), perforins, as well as gasdermins. While the primary function of perforin-1 and gasdermins is to eliminate infected or cancerous host cells, perforin-2 and MAC can target pathogens directly. Yet, all mammalian PFPs are in principle capable of generating pores in membranes of healthy host cells which-if uncontrolled-could have dire, and potentially lethal consequences. In this review, we will highlight the strategies employed to protect the host from destruction by endogenous PFPs, while enabling timely and efficient elimination of target cells.
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Affiliation(s)
- Patrycja A Krawczyk
- MRC Laboratory of Molecular Biology, Protein and Nucleic Acid Chemistry Division, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Marco Laub
- MRC Laboratory of Molecular Biology, Protein and Nucleic Acid Chemistry Division, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Patrycja Kozik
- MRC Laboratory of Molecular Biology, Protein and Nucleic Acid Chemistry Division, Cambridge Biomedical Campus, Cambridge, United Kingdom
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263
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Mondal AK, Verma P, Sengupta N, Dutta S, Bhushan Pandit S, Chattopadhyay K. Tyrosine in the hinge region of the pore-forming motif regulates oligomeric β-barrel pore formation by Vibrio cholerae cytolysin. Mol Microbiol 2020; 115:508-525. [PMID: 33089544 DOI: 10.1111/mmi.14631] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/03/2020] [Indexed: 01/27/2023]
Abstract
β-barrel pore-forming toxins perforate cell membranes by forming oligomeric β-barrel pores. The most crucial step is the membrane-insertion of the pore-forming motifs that create the transmembrane β-barrel scaffold. Molecular mechanism that regulates structural reorganization of these pore-forming motifs during β-barrel pore-formation still remains elusive. Using Vibrio cholerae cytolysin as an archetypical example of the β-barrel pore-forming toxin, we show that a key tyrosine residue (Y321) in the hinge region of the pore-forming motif plays crucial role in this process. Mutation of Y321 abrogates oligomerization of the membrane-bound toxin protomers, and blocks subsequent steps of pore-formation. Our study suggests that the presence of Y321 in the hinge region of the pore-forming motif is crucial for the toxin molecule to sense membrane-binding, and to trigger essential structural rearrangements required for the subsequent oligomerization and pore-formation process. Such a regulatory mechanism of pore-formation by V. cholerae cytolysin has not been documented earlier in the structurally related β-barrel pore-forming toxins.
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Affiliation(s)
- Anish Kumar Mondal
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Paras Verma
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Nayanika Sengupta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Somnath Dutta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Shashi Bhushan Pandit
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
| | - Kausik Chattopadhyay
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, India
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264
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Snelders NC, Rovenich H, Petti GC, Rocafort M, van den Berg GCM, Vorholt JA, Mesters JR, Seidl MF, Nijland R, Thomma BPHJ. Microbiome manipulation by a soil-borne fungal plant pathogen using effector proteins. NATURE PLANTS 2020; 6:1365-1374. [PMID: 33139860 DOI: 10.1038/s41477-020-00799-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 09/29/2020] [Indexed: 05/23/2023]
Abstract
During colonization of their hosts, pathogens secrete effector proteins to promote disease development through various mechanisms. Increasing evidence shows that the host microbiome plays a crucial role in health, and that hosts actively shape their microbiomes to suppress disease. We proposed that pathogens evolved to manipulate host microbiomes to their advantage in turn. Here, we show that the previously identified virulence effector VdAve1, secreted by the fungal plant pathogen Verticillium dahliae, displays antimicrobial activity and facilitates colonization of tomato and cotton through the manipulation of their microbiomes by suppressing antagonistic bacteria. Moreover, we show that VdAve1, and also the newly identified antimicrobial effector VdAMP2, are exploited for microbiome manipulation in the soil environment, where the fungus resides in absence of a host. In conclusion, we demonstrate that a fungal plant pathogen uses effector proteins to modulate microbiome compositions inside and outside the host, and propose that pathogen effector catalogues represent an untapped resource for new antibiotics.
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Affiliation(s)
- Nick C Snelders
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Hanna Rovenich
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | - Gabriella C Petti
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Mercedes Rocafort
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Grardy C M van den Berg
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
| | | | - Jeroen R Mesters
- Institute of Biochemistry, University of Lübeck, Center for Structural and Cell Biology in Medicine, Lübeck, Germany
| | - Michael F Seidl
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- Theoretical Biology & Bioinformatics Group, Department of Biology, Utrecht University, Utrecht, the Netherlands
| | - Reindert Nijland
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands
- Marine Animal Ecology Group, Wageningen University and Research, Wageningen, the Netherlands
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University and Research, Wageningen, the Netherlands.
- Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Botanical Institute, Cologne, Germany.
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265
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Molecular Dynamics Study of Lipid and Cholesterol Reorganization Due to Membrane Binding and Pore Formation by Listeriolysin O. J Membr Biol 2020; 253:535-550. [DOI: 10.1007/s00232-020-00148-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 10/10/2020] [Indexed: 12/20/2022]
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266
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Karan S, Choudhury D, Dixit A. Enhanced expression of recombinant proteins in Escherichia coli by co-expression with Vibrio parahaemolyticus CsgG, a pore-forming protein of the curli biogenesis pathway. J Appl Microbiol 2020; 130:1611-1629. [PMID: 33025668 DOI: 10.1111/jam.14886] [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: 04/01/2020] [Revised: 09/11/2020] [Accepted: 09/30/2020] [Indexed: 11/28/2022]
Abstract
AIM To test whether engineered nanopores on the outer membrane (OM) of Escherichia coli can increase expression of heterologous proteins by making additional nutrients available to the host. METHODS AND RESULTS Outer membrane nanopores were generated by expressing recombinant Vibrio parahaemolyticus CsgG (rVpCsgG), which spontaneously assembles into a pore-forming channel on the OM, allowing spontaneous diffusion of small chemical entities from the exterior. Protein expression was probed using a reporter protein, sfGFP, expressed on a second compatible plasmid. OM pore formation was shown by acquired erythromycin sensitivity in cells transformed with rVpCsgG, influx of propidium iodide as well as by surface localization of recombinant CsgG by immunogold-labeled transmission electron microscopy. Expression of recombinant CsgG showed increased growth and also enhanced expression of sfGFP in minimal medium and is due to both enhanced transcription as well as translation. Similar enhancement of expression was also observed for a number of different proteins of different origin, sizes and nature. CONCLUSIONS Our findings clearly demonstrate that engineered nanopores on the OM of E. coli enhance expression of different heterologous proteins in minimal medium. SIGNIFICANCE AND IMPACT OF THE STUDY Vibrio parahaemolyticus CsgG β-nanopore mediated co-expression strategy to improve recombinant protein expression is fully compatible with other methods of protein expression enhancement, and therefore can be a useful tool in biotechnology particularly for whole-cell bio-transformations for production of secondary metabolite.
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Affiliation(s)
- S Karan
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - D Choudhury
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - A Dixit
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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267
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Romp E, Arakandy V, Fischer J, Wolz C, Siegmund A, Löffler B, Tuchscherr L, Werz O, Garscha U. Exotoxins from Staphylococcus aureus activate 5-lipoxygenase and induce leukotriene biosynthesis. Cell Mol Life Sci 2020; 77:3841-3858. [PMID: 31807813 PMCID: PMC11105070 DOI: 10.1007/s00018-019-03393-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/14/2019] [Accepted: 11/22/2019] [Indexed: 11/29/2022]
Abstract
Massive neutrophil infiltration is an early key event in infectious inflammation, accompanied by chemotactic leukotriene (LT)B4 generation. LTB4 biosynthesis is mediated by 5-lipoxygenase (5-LOX), but which pathogenic factors cause 5-LOX activation during bacterial infections is elusive. Here, we reveal staphylococcal exotoxins as 5-LOX activators. Conditioned medium of wild-type Staphylococcus aureus but not of exotoxin-deficient strains induced 5-LOX activation in transfected HEK293 cells. Two different staphylococcal exotoxins mimicked the effects of S. aureus-conditioned medium: (1) the pore-forming toxin α-hemolysin and (2) amphipathic α-helical phenol-soluble modulin (PSM) peptides. Interestingly, in human neutrophils, 5-LOX activation was exclusively evoked by PSMs, which was prevented by the selective FPR2/ALX receptor antagonist WRW4. 5-LOX activation by PSMs was confirmed in vivo as LT formation in infected paws of mice was impaired in response to PSM-deficient S. aureus. Conclusively, exotoxins from S. aureus are potent pathogenic factors that activate 5-LOX and induce LT formation in neutrophils.
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Affiliation(s)
- Erik Romp
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Vandana Arakandy
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Jana Fischer
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, 72076, Tuebingen, Germany
| | - Anke Siegmund
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Lorena Tuchscherr
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Oliver Werz
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Ulrike Garscha
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany.
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268
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Subramanian K, Iovino F, Tsikourkitoudi V, Merkl P, Ahmed S, Berry SB, Aschtgen MS, Svensson M, Bergman P, Sotiriou GA, Henriques-Normark B. Mannose receptor-derived peptides neutralize pore-forming toxins and reduce inflammation and development of pneumococcal disease. EMBO Mol Med 2020; 12:e12695. [PMID: 32985105 PMCID: PMC7645366 DOI: 10.15252/emmm.202012695] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/30/2020] [Accepted: 09/02/2020] [Indexed: 12/30/2022] Open
Abstract
Cholesterol‐dependent cytolysins (CDCs) are essential virulence factors for many human pathogens like Streptococcus pneumoniae (pneumolysin, PLY), Streptococcus pyogenes (streptolysin O, SLO), and Listeria monocytogenes (Listeriolysin, LLO) and induce cytolysis and inflammation. Recently, we identified that pneumococcal PLY interacts with the mannose receptor (MRC‐1) on specific immune cells thereby evoking an anti‐inflammatory response at sublytic doses. Here, we identified the interaction sites between MRC‐1 and CDCs using computational docking. We designed peptides from the CTLD4 domain of MRC‐1 that binds to PLY, SLO, and LLO, respectively. In vitro, the peptides blocked CDC‐induced cytolysis and inflammatory cytokine production by human macrophages. Also, they reduced PLY‐induced damage of the epithelial barrier integrity as well as blocked bacterial invasion into the epithelium in a 3D lung tissue model. Pre‐treatment of human DCs with peptides blocked bacterial uptake via MRC‐1 and reduced intracellular bacterial survival by targeting bacteria to autophagosomes. In order to use the peptides for treatment in vivo, we developed calcium phosphate nanoparticles (CaP NPs) as peptide nanocarriers for intranasal delivery of peptides and enhanced bioactivity. Co‐administration of peptide‐loaded CaP NPs during infection improved survival and bacterial clearance in both zebrafish and mice models of pneumococcal infection. We suggest that MRC‐1 peptides can be employed as adjunctive therapeutics with antibiotics to treat bacterial infections by countering the action of CDCs.
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Affiliation(s)
- Karthik Subramanian
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Federico Iovino
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Vasiliki Tsikourkitoudi
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Padryk Merkl
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sultan Ahmed
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Samuel B Berry
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden
| | | | - Mattias Svensson
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden
| | - Peter Bergman
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden.,The Immunodeficiency Unit, Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Georgios A Sotiriou
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden.,Lee Kong Chian School of Medicine (LKC) and Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
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269
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Mondal AK, Verma P, Lata K, Singh M, Chatterjee S, Chattopadhyay K. Sequence Diversity in the Pore-Forming Motifs of the Membrane-Damaging Protein Toxins. J Membr Biol 2020; 253:469-478. [PMID: 32955633 DOI: 10.1007/s00232-020-00141-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 09/08/2020] [Indexed: 12/21/2022]
Abstract
Pore-forming proteins/toxins (PFPs/PFTs) are the distinct class of membrane-damaging proteins. They act by forming oligomeric pores in the plasma membranes. PFTs and PFPs from diverse organisms share a common mechanism of action, in which the designated pore-forming motifs of the membrane-bound protein molecules insert into the membrane lipid bilayer to create the water-filled pores. One common characteristic of these pore-forming motifs is that they are amphipathic in nature. In general, the hydrophobic sidechains of the pore-forming motifs face toward the hydrophobic core of the membranes, while the hydrophilic residues create the lining of the water-filled pore lumen. Interestingly, pore-forming motifs of the distinct subclass of PFPs/PFTs share very little sequence similarity with each other. Therefore, the common guiding principle that governs the sequence-to-structure paradigm in the mechanism of action of these PFPs/PFTs still remains an enigma. In this article, we discuss this notion using the examples of diverse groups of membrane-damaging PFPs/PFTs.
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Affiliation(s)
- Anish Kumar Mondal
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Pratima Verma
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Kusum Lata
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Mahendra Singh
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Shamaita Chatterjee
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, Mohali, Punjab, 140306, India
| | - Kausik Chattopadhyay
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S. A. S. Nagar, Manauli, Mohali, Punjab, 140306, India.
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270
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Tawfik H, Puza S, Seemann R, Fleury JB. Transport Properties of Gramicidin A Ion Channel in a Free-Standing Lipid Bilayer Filled With Oil Inclusions. Front Cell Dev Biol 2020; 8:531229. [PMID: 33015051 PMCID: PMC7498540 DOI: 10.3389/fcell.2020.531229] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 08/14/2020] [Indexed: 11/13/2022] Open
Abstract
Ion channels are key proteins in mammalian cell membranes. They have a central role in the physiology of excitable cells such as neurons, muscle, and heart cells. They also play a crucial role in kidney physiology. The gramicidin ion channel is one of the most studied ion channels, in particular it was intensively employed to investigate the lipid–protein interactions in model cell membranes. For example, even though the sequence of gramicidin is extremely hydrophobic, its motion is impaired in membrane bilayer, i.e., it does not rapidly flip to the other membrane leaflet, and low channel activity were observed when gramicidin is added asymmetrically to only one leaflet of a model cell membrane. In this article, we study the transport properties of gramicidin channel in a heterogeneous model membrane. Using microfluidics, we are forming freestanding bilayers as model cell membranes including heterogeneous domains that are created by oil inclusions. The presence of oil inclusions is then demonstrated by measuring the bilayer capacity via a patch-clamp amplifier and fluorescent confocal inspection. Based on electrophysiological and optical measurements Gramicidin A (gA) ion channels are dispersed into the buffer phases on both side of the formed lipid bilayer and insert spontaneously into the bilayer upon formation. The presence of functional Gramicidin A is then demonstrated by measuring conductivity signals. Based on electrophysiological and optical measurements, we explore the consequence of the presence of these oil inclusions on the functionality of incorporated gA ion channels. For low oil concentration, we measure a decrease of gA transport properties due to the reduction of the bilayer tension. For large oil concentration, we measure a saturation of gA transport properties due to an increase of the bilayer thickness.
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Affiliation(s)
- Harvey Tawfik
- Experimental Physics and Center for Biophysics, Universität des Saarlandes, Saarbrücken, Germany
| | - Sevde Puza
- Experimental Physics and Center for Biophysics, Universität des Saarlandes, Saarbrücken, Germany
| | - Ralf Seemann
- Experimental Physics and Center for Biophysics, Universität des Saarlandes, Saarbrücken, Germany
| | - Jean-Baptiste Fleury
- Experimental Physics and Center for Biophysics, Universität des Saarlandes, Saarbrücken, Germany
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271
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Spatiotemporal Regulation of Vibrio Exotoxins by HlyU and Other Transcriptional Regulators. Toxins (Basel) 2020; 12:toxins12090544. [PMID: 32842612 PMCID: PMC7551375 DOI: 10.3390/toxins12090544] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
After invading a host, bacterial pathogens secrete diverse protein toxins to disrupt host defense systems. To ensure successful infection, however, pathogens must precisely regulate the expression of those exotoxins because uncontrolled toxin production squanders energy. Furthermore, inappropriate toxin secretion can trigger host immune responses that are detrimental to the invading pathogens. Therefore, bacterial pathogens use diverse transcriptional regulators to accurately regulate multiple exotoxin genes based on spatiotemporal conditions. This review covers three major exotoxins in pathogenic Vibrio species and their transcriptional regulation systems. When Vibrio encounters a host, genes encoding cytolysin/hemolysin, multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin, and secreted phospholipases are coordinately regulated by the transcriptional regulator HlyU. At the same time, however, they are distinctly controlled by a variety of other transcriptional regulators. How this coordinated but distinct regulation of exotoxins makes Vibrio species successful pathogens? In addition, anti-virulence strategies that target the coordinating master regulator HlyU and related future research directions are discussed.
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272
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Syed S, Viazmina L, Mager R, Meri S, Haapasalo K. Streptococci and the complement system: interplay during infection, inflammation and autoimmunity. FEBS Lett 2020; 594:2570-2585. [PMID: 32594520 DOI: 10.1002/1873-3468.13872] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 11/09/2022]
Abstract
Streptococci are a broad group of Gram-positive bacteria. This genus includes various human pathogens causing significant morbidity and mortality. Two of the most important human pathogens are Streptococcus pneumoniae (pneumococcus) and Streptococcus pyogenes (group A streptococcus or GAS). Streptococcal pathogens have evolved to express virulence factors that enable them to evade complement-mediated attack. These include factor H-binding M (S. pyogenes) and pneumococcal surface protein C (PspC) (S. pneumoniae) proteins. In addition, S. pyogenes and S. pneumoniae express cytolysins (streptolysin and pneumolysin), which are able to destroy host cells. Sometimes, the interplay between streptococci, the complement, and antistreptococcal immunity may lead to an excessive inflammatory response or autoimmune disease. Understanding the fundamental role of the complement system in microbial clearance and the bacterial escape mechanisms is of paramount importance for understanding microbial virulence, in general, and, the conversion of commensals to pathogens, more specifically. Such insights may help to identify novel antibiotic and vaccine targets in bacterial pathogens to counter their growing resistance to commonly used antibiotics.
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Affiliation(s)
- Shahan Syed
- Department of Bacteriology and Immunology, University of Helsinki, Finland
| | - Larisa Viazmina
- Department of Bacteriology and Immunology, University of Helsinki, Finland
| | | | - Seppo Meri
- Department of Bacteriology and Immunology, University of Helsinki, Finland.,Humanitas University, Milano, Italy
| | - Karita Haapasalo
- Department of Bacteriology and Immunology, University of Helsinki, Finland
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273
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Deng C, Liu L, Liu L, Wang Q, Guo X, Lee W, Li S, Zhang Y. A secreted pore‐forming protein modulates cellular endolysosomes to augment antigen presentation. FASEB J 2020; 34:13609-13625. [DOI: 10.1096/fj.202001176r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Cheng‐Jie Deng
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
- Kunming College of Life Science University of Chinese Academy of Sciences Kunming China
| | - Long Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
- Kunming College of Life Science University of Chinese Academy of Sciences Kunming China
| | - Ling‐Zhen Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
- Kunming College of Life Science University of Chinese Academy of Sciences Kunming China
| | - Qi‐Quan Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
- Kunming College of Life Science University of Chinese Academy of Sciences Kunming China
| | - Xiao‐Long Guo
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
| | - Wen‐Hui Lee
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
| | - Sheng‐An Li
- Department of Pathogen Biology and Immunology Faculty of Basic Medical Science Kunming Medical University Kunming China
| | - Yun Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province Kunming Institute of Zoology The Chinese Academy of Sciences Kunming China
- Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences Kunming China
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274
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A membrane-depolarizing toxin substrate of the Staphylococcus aureus type VII secretion system mediates intraspecies competition. Proc Natl Acad Sci U S A 2020; 117:20836-20847. [PMID: 32769205 PMCID: PMC7456083 DOI: 10.1073/pnas.2006110117] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The type VII protein secretion system (T7SS) is conserved across Staphylococcus aureus strains and plays important roles in virulence and interbacterial competition. To date, only one T7SS substrate protein, encoded in a subset of S. aureus genomes, has been functionally characterized. Here, using an unbiased proteomic approach, we identify TspA as a further T7SS substrate. TspA is encoded distantly from the T7SS gene cluster and is found across all S. aureus strains as well as in Listeria and Enterococci. Heterologous expression of TspA from S. aureus strain RN6390 indicates its C-terminal domain is toxic when targeted to the Escherichia coli periplasm and that it depolarizes the cytoplasmic membrane. The membrane-depolarizing activity is alleviated by coproduction of the membrane-bound TsaI immunity protein, which is encoded adjacent to tspA on the S. aureus chromosome. Using a zebrafish hindbrain ventricle infection model, we demonstrate that the T7SS of strain RN6390 promotes bacterial replication in vivo, and deletion of tspA leads to increased bacterial clearance. The toxin domain of TspA is highly polymorphic and S. aureus strains encode multiple tsaI homologs at the tspA locus, suggestive of additional roles in intraspecies competition. In agreement, we demonstrate TspA-dependent growth inhibition of RN6390 by strain COL in the zebrafish infection model that is alleviated by the presence of TsaI homologs.
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275
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Giglio ML, Ituarte S, Milesi V, Dreon MS, Brola TR, Caramelo J, Ip JCH, Maté S, Qiu JW, Otero LH, Heras H. Exaptation of two ancient immune proteins into a new dimeric pore-forming toxin in snails. J Struct Biol 2020; 211:107531. [PMID: 32446810 DOI: 10.1016/j.jsb.2020.107531] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/01/2020] [Accepted: 05/14/2020] [Indexed: 11/24/2022]
Abstract
The Membrane Attack Complex-Perforin (MACPF) family is ubiquitously found in all kingdoms. They have diverse cellular roles, however MACPFs with pore-forming toxic function in venoms and poisons are very rare in animals. Here we present the structure of PmPV2, a MACPF toxin from the poisonous apple snail eggs, that can affect the digestive and nervous systems of potential predators. We report the three-dimensional structure of PmPV2, at 17.2 Å resolution determined by negative-stain electron microscopy and its solution structure by small angle X-ray scattering (SAXS). We found that PV2s differ from nearly all MACPFs in two respects: it is a dimer in solution and protomers combine two immune proteins into an AB toxin. The MACPF chain is linked by a single disulfide bond to a tachylectin chain, and two heterodimers are arranged head-to-tail by non-covalent forces in the native protein. MACPF domain is fused with a putative new Ct-accessory domain exclusive to invertebrates. The tachylectin is a six-bladed β-propeller, similar to animal tectonins. We experimentally validated the predicted functions of both subunits and demonstrated for the first time that PV2s are true pore-forming toxins. The tachylectin "B" delivery subunit would bind to target membranes, and then the MACPF "A" toxic subunit would disrupt lipid bilayers forming large pores altering the plasma membrane conductance. These results indicate that PV2s toxicity evolved by linking two immune proteins where their combined preexisting functions gave rise to a new toxic entity with a novel role in defense against predation. This structure is an unparalleled example of protein exaptation.
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Affiliation(s)
- M L Giglio
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas,1900 La Plata, Argentina
| | - S Ituarte
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas,1900 La Plata, Argentina
| | - V Milesi
- Instituto de Estudios Inmunológicos y Fisiopatológicos, IIFP CONICET CCT La Plata - UNLP, Facultad de Ciencias Exactas, 1900 La Plata, Argentina
| | - M S Dreon
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas,1900 La Plata, Argentina
| | - T R Brola
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas,1900 La Plata, Argentina
| | - J Caramelo
- Instituto de Investigaciones Bioquímicas de Buenos Aires, IIBBA, CONICET - Fundación Instituto Leloir, Av Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - J C H Ip
- Department of Biology, Hong Kong Baptist University, 224 Waterloo Road, Hong Kong, China
| | - S Maté
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas,1900 La Plata, Argentina
| | - J W Qiu
- Department of Biology, Hong Kong Baptist University, 224 Waterloo Road, Hong Kong, China
| | - L H Otero
- Instituto de Investigaciones Bioquímicas de Buenos Aires, IIBBA, CONICET - Fundación Instituto Leloir, Av Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina; Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina.
| | - H Heras
- Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner", INIBIOLP, CONICET CCT La Plata - Universidad Nacional de La Plata (UNLP), Facultad de Ciencias Médicas,1900 La Plata, Argentina; Cátedra de Química Biologica, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata (UNLP), 1900 La Plata, Argentina.
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276
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Lencer WI. Everything Illuminated-Clostridium perfringens β-toxin. Cell Host Microbe 2020; 28:5-6. [PMID: 32645353 DOI: 10.1016/j.chom.2020.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In this issue of Cell Host & Microbe, Bruggisser et al. show that Clostridium perfringens β-toxin (CPB) binds platelet endothelial cell adhesion molecule-1 (PECAM-1) (also known as CD31) to induce membrane pores. The discovery explains the cell type specificity for CPB and, in large part, the basic pathophysiology of disease.
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Affiliation(s)
- Wayne I Lencer
- Boston Children's Hospital, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA; Harvard Digestive Disease Center, Boston, MA 02115, USA.
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277
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Liu XY, Hu Q, Xu F, Ding SY, Zhu K. Characterization of Bacillus cereus in Dairy Products in China. Toxins (Basel) 2020; 12:E454. [PMID: 32674390 PMCID: PMC7405013 DOI: 10.3390/toxins12070454] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023] Open
Abstract
Bacillus cereus is a common and ubiquitous foodborne pathogen with an increasing prevalence rate in dairy products in China. High and unmet demands for such products, particularly milk, raise the risk of B. cereus associated contamination. The presence of B. cereus and its virulence factors in dairy products may cause food poisoning and other illnesses. Thus, this review first summarizes the epidemiological characteristics and analytical assays of B. cereus from dairy products in China, providing insights into the implementation of intervention strategies. In addition, the recent achievements on the cytotoxicity and mechanisms of B. cereus are also presented to shed light on the therapeutic options for B. cereus associated infections.
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Affiliation(s)
- Xiao-Ye Liu
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.-Y.L.); (Q.H.)
- Department of Mechanics and Engineering Science, College of Engineering, Academy for Advanced Interdisciplinary Studies, and Beijing Advanced Innovation Center for Engineering Science and Emerging Technology, College of Engineering, Peking University, Beijing 100871, China
| | - Qiao Hu
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.-Y.L.); (Q.H.)
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
| | - Fei Xu
- National Feed Drug Reference Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
| | - Shuang-Yang Ding
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
| | - Kui Zhu
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; (X.-Y.L.); (Q.H.)
- National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
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278
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Cortex Cercis chinensis Granules Attenuate Streptococcus pneumoniae Virulence by Targeting Pneumolysin. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:8537026. [PMID: 32617112 PMCID: PMC7315261 DOI: 10.1155/2020/8537026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/03/2020] [Accepted: 05/12/2020] [Indexed: 11/17/2022]
Abstract
Pore-forming toxins produced by bacteria are some of the most important molecular weapons for bacterial virulence. Pneumolysin (PLY) is a pore-forming toxin secreted by Streptococcus pneumoniae (S. pneumoniae) and plays a vital role in the spread, colonization, and invasion of this bacterium in the host, indicating that PLY is a promising target for developing treatments against S. pneumoniae infection. In this study, Cortex Cercis chinensis granules (CCCGs), a prescription drug on the market, were shown to inhibit the pore-forming activity of PLY and protect against PLY-mediated cell hemolysis and A549 cell death without antibacterial activity or inhibition of PLY production. In addition, CCCG treatment inhibited the oligomerization of PLY. Animal experiments showed that CCCGs can reduce the death of mice infected with S. pneumoniae, the degree of pathological damage to the lungs, and the levels of TNF-α and IL-6 in the lungs. In summary, our results demonstrated that CCCGs, a marketed Chinese medicine, inhibit PLY activity and subsequently attenuate S. pneumoniae virulence, which would offer a novel strategy for fighting S. pneumoniae infection and a new use for CCCGs.
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279
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Exolysin (ExlA) from Pseudomonas aeruginosa Punctures Holes into Target Membranes Using a Molten Globule Domain. J Mol Biol 2020; 432:4466-4480. [DOI: 10.1016/j.jmb.2020.05.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 12/19/2022]
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280
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Schubert T, Sych T, Madl J, Xu M, Omidvar R, Patalag LJ, Ries A, Kettelhoit K, Brandel A, Mely Y, Steinem C, Werz DB, Thuenauer R, Römer W. Differential recognition of lipid domains by two Gb3-binding lectins. Sci Rep 2020; 10:9752. [PMID: 32546842 PMCID: PMC7297801 DOI: 10.1038/s41598-020-66522-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
The two lectins LecA from Pseudomonas aeruginosa and the B-subunit of Shiga toxin from Shigella dysenteriae (StxB) share the glycosphingolipid globotriaosylceramide (Gb3) as receptor. Counterintuitively, we found that LecA and StxB segregated into different domains after recognizing Gb3 at the plasma membrane of cells. We hypothesized that the orientation of the carbohydrate head group of Gb3 embedded in the lipid bilayer differentially influences LecA and StxB binding. To test this hypothesis, we reconstituted lectin-Gb3 interaction using giant unilamellar vesicles and were indeed able to rebuild LecA and StxB segregation. Both, the Gb3 fatty acyl chain structure and the local membrane environment, modulated Gb3 recognition by LecA and StxB. Specifically, StxB preferred more ordered membranes compared to LecA. Based on our findings, we propose comparing staining patterns of LecA and StxB as an alternative method to assess membrane order in cells. To verify this approach, we re-established that the apical plasma membrane of epithelial cells is more ordered than the basolateral plasma membrane. Additionally, we found that StxB recognized Gb3 at the primary cilium and the periciliary membrane, whereas LecA only bound periciliary Gb3. This suggests that the ciliary membrane is of higher order than the surrounding periciliary membrane.
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Affiliation(s)
- Thomas Schubert
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Toolbox, BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Taras Sych
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS, Faculty of Pharmacy, University of Strasbourg, Strasbourg, France
| | - Josef Madl
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Maokai Xu
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Ramin Omidvar
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Lukas J Patalag
- Technische Universität Braunschweig, Institut für Organische Chemie, Braunschweig, Germany
| | - Annika Ries
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Katharina Kettelhoit
- Technische Universität Braunschweig, Institut für Organische Chemie, Braunschweig, Germany
| | - Annette Brandel
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Yves Mely
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS, Faculty of Pharmacy, University of Strasbourg, Strasbourg, France
| | - Claudia Steinem
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Daniel B Werz
- Technische Universität Braunschweig, Institut für Organische Chemie, Braunschweig, Germany
| | - Roland Thuenauer
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany. .,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany. .,Advanced Light and Fluorescence Microscopy Facility, Centre for Structural Systems Biology (CSSB) and University of Hamburg, Hamburg, Germany.
| | - Winfried Römer
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany. .,Synthetic Biology of Signalling Processes, Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany.
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281
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Liu J, Zuo Z, Sastalla I, Liu C, Jang JY, Sekine Y, Li Y, Pirooznia M, Leppla SH, Finkel T, Liu S. Sequential CRISPR-Based Screens Identify LITAF and CDIP1 as the Bacillus cereus Hemolysin BL Toxin Host Receptors. Cell Host Microbe 2020; 28:402-410.e5. [PMID: 32544461 DOI: 10.1016/j.chom.2020.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/16/2020] [Accepted: 05/15/2020] [Indexed: 12/18/2022]
Abstract
Bacteria and their toxins are associated with significant human morbidity and mortality. While a few bacterial toxins are well characterized, the mechanism of action for most toxins has not been elucidated, thereby limiting therapeutic advances. One such example is the highly potent pore-forming toxin, hemolysin BL (HBL), produced by the gram-positive pathogen Bacillus cereus. However, how HBL exerts its effects and whether it requires any host factors is unknown. Here, we describe an unbiased genome-wide CRISPR-Cas9 knockout screen that identified LPS-induced TNF-α factor (LITAF) as the HBL receptor. Using LITAF-deficient cells, a second, subsequent whole-genome CRISPR-Cas9 screen identified the LITAF-like protein CDIP1 as a second, alternative receptor. We generated LITAF-deficient mice, which exhibit marked resistance to lethal HBL challenges. This work outlines and validates an approach to use iterative genome-wide CRISPR-Cas9 screens to identify the complement of host factors exploited by bacterial toxins to exert their myriad biological effects.
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Affiliation(s)
- Jie Liu
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zehua Zuo
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Inka Sastalla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chengyu Liu
- Transgenic Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ji Yong Jang
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Yusuke Sekine
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA
| | - Yuesheng Li
- DNA Sequencing and Genomics Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mehdi Pirooznia
- Bioinformatics and Computational Biology Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Toren Finkel
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Shihui Liu
- Aging Institute of University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, PA 15219, USA; Division of Infectious Diseases, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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282
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Crossing the Vacuolar Rubicon: Structural Insights into Effector Protein Trafficking in Apicomplexan Parasites. Microorganisms 2020; 8:microorganisms8060865. [PMID: 32521667 PMCID: PMC7355975 DOI: 10.3390/microorganisms8060865] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/01/2020] [Accepted: 06/05/2020] [Indexed: 12/13/2022] Open
Abstract
Apicomplexans form a large phylum of parasitic protozoa, including the genera Plasmodium, Toxoplasma, and Cryptosporidium, the causative agents of malaria, toxoplasmosis, and cryptosporidiosis, respectively. They cause diseases not only in humans but also in animals, with dramatic consequences in agriculture. Most apicomplexans are vacuole-dwelling and obligate intracellular parasites; as they invade the host cell, they become encased in a parasitophorous vacuole (PV) derived from the host cellular membrane. This creates a parasite-host interface that acts as a protective barrier but also constitutes an obstacle through which the pathogen must import nutrients, eliminate wastes, and eventually break free upon egress. Completion of the parasitic life cycle requires intense remodeling of the infected host cell. Host cell subversion is mediated by a subset of essential effector parasitic proteins and virulence factors actively trafficked across the PV membrane. In the malaria parasite Plasmodium, a unique and highly specialized ATP-driven vacuolar secretion system, the Plasmodium translocon of exported proteins (PTEX), transports effector proteins across the vacuolar membrane. Its core is composed of the three essential proteins EXP2, PTEX150, and HSP101, and is supplemented by the two auxiliary proteins TRX2 and PTEX88. Many but not all secreted malarial effector proteins contain a vacuolar trafficking signal or Plasmodium export element (PEXEL) that requires processing by an endoplasmic reticulum protease, plasmepsin V, for proper export. Because vacuolar parasitic protein export is essential to parasite survival and virulence, this pathway is a promising target for the development of novel antimalarial therapeutics. This review summarizes the current state of structural and mechanistic knowledge on the Plasmodium parasitic vacuolar secretion and effector trafficking pathway, describing its most salient features and discussing the existing differences and commonalities with the vacuolar effector translocation MYR machinery recently described in Toxoplasma and other apicomplexans of significance to medical and veterinary sciences.
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283
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Wang Q, Bian X, Zeng L, Pan F, Liu L, Liang J, Wang L, Zhou K, Lee W, Xiang Y, Li S, Teng M, Li X, Guo X, Zhang Y. A cellular endolysosome-modulating pore-forming protein from a toad is negatively regulated by its paralog under oxidizing conditions. J Biol Chem 2020; 295:10293-10306. [PMID: 32499370 DOI: 10.1074/jbc.ra120.013556] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/22/2020] [Indexed: 01/05/2023] Open
Abstract
Endolysosomes are key players in cell physiology, including molecular exchange, immunity, and environmental adaptation. They are the molecular targets of some pore-forming aerolysin-like proteins (ALPs) that are widely distributed in animals and plants and are functionally related to bacterial toxin aerolysins. βγ-CAT is a complex of an ALP (BmALP1) and a trefoil factor (BmTFF3) in the firebelly toad (Bombina maxima). It is the first example of a secreted endogenous pore-forming protein that modulates the biochemical properties of endolysosomes by inducing pore formation in these intracellular vesicles. Here, using a large array of biochemical and cell biology methods, we report the identification of BmALP3, a paralog of BmALP1 that lacks membrane pore-forming capacity. We noted that both BmALP3 and BmALP1 contain a conserved cysteine in their C-terminal regions. BmALP3 was readily oxidized to a disulfide bond-linked homodimer, and this homodimer then oxidized BmALP1 via disulfide bond exchange, resulting in the dissociation of βγ-CAT subunits and the elimination of biological activity. Consistent with its behavior in vitro, BmALP3 sensed environmental oxygen tension in vivo, leading to modulation of βγ-CAT activity. Interestingly, we found that this C-terminal cysteine site is well conserved in numerous vertebrate ALPs. These findings uncover the existence of a regulatory ALP (BmALP3) that modulates the activity of an active ALP (BmALP1) in a redox-dependent manner, a property that differs from those of bacterial toxin aerolysins.
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Affiliation(s)
- Qiquan Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xianling Bian
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Lin Zeng
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Fei Pan
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Lingzhen Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Jinyang Liang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Lingyan Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Kaifeng Zhou
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Wenhui Lee
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yang Xiang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Sheng'an Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China
| | - Xiaolong Guo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yun Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China .,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, Yunnan, China
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284
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Bruggisser J, Tarek B, Wyder M, Müller P, von Ballmoos C, Witz G, Enzmann G, Deutsch U, Engelhardt B, Posthaus H. CD31 (PECAM-1) Serves as the Endothelial Cell-Specific Receptor of Clostridium perfringens β-Toxin. Cell Host Microbe 2020; 28:69-78.e6. [PMID: 32497498 DOI: 10.1016/j.chom.2020.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/31/2020] [Accepted: 05/05/2020] [Indexed: 01/25/2023]
Abstract
Clostridium perfringens β-toxin (CPB) is a highly active β-pore-forming toxin (β-PFT) and the essential virulence factor for fatal, necro-hemorrhagic enteritis in animals and humans. The molecular mechanisms involved in CPB's action on its target, the endothelium of small intestinal vessels, are poorly understood. Here, we identify platelet endothelial cell adhesion molecule-1 (CD31 or PECAM-1) as the specific membrane receptor for CPB on endothelial cells. CD31 expression corresponds with the cell-type specificity of CPB, and it is essential for toxicity in cultured cells and mice. Ectopic CD31 expression renders resistant cells and liposomes susceptible to CPB-induced membrane damage. Moreover, the extracellular Ig6 domain of mouse, human, and porcine CD31 is essential for the interaction with CPB. Hence, our results explain the cell-type specificity of CPB in vitro and in the natural disease caused by C. perfringens type C.
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Affiliation(s)
- Julia Bruggisser
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland
| | - Basma Tarek
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland
| | - Marianne Wyder
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland
| | - Philipp Müller
- Department of Chemistry and Biochemistry, Faculty of Sciences, University of Bern, 3012 Bern, Switzerland
| | - Christoph von Ballmoos
- Department of Chemistry and Biochemistry, Faculty of Sciences, University of Bern, 3012 Bern, Switzerland
| | - Guillaume Witz
- Microscopy Imaging Center (MIC) University of Bern, 3012 Bern, Switzerland; Science IT Support (ScITS), Mathematical Institute, University of Bern, Bern, Switzerland
| | - Gaby Enzmann
- Theodor Kocher Institute, Faculty of Medicine, University of Bern, 3012 Bern, Switzerland
| | - Urban Deutsch
- Theodor Kocher Institute, Faculty of Medicine, University of Bern, 3012 Bern, Switzerland
| | - Britta Engelhardt
- Theodor Kocher Institute, Faculty of Medicine, University of Bern, 3012 Bern, Switzerland
| | - Horst Posthaus
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland; COMPATH, Vetsuisse-Faculty & Faculty of Medicine, University of Bern, 3012 Bern, Switzerland.
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285
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Liu J, Fraire JC, De Smedt SC, Xiong R, Braeckmans K. Intracellular Labeling with Extrinsic Probes: Delivery Strategies and Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2000146. [PMID: 32351015 DOI: 10.1002/smll.202000146] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/29/2020] [Accepted: 03/16/2020] [Indexed: 06/11/2023]
Abstract
Extrinsic probes have outstanding properties for intracellular labeling to visualize dynamic processes in and of living cells, both in vitro and in vivo. Since extrinsic probes are in many cases cell-impermeable, different biochemical, and physical approaches have been used to break the cell membrane barrier for direct delivery into the cytoplasm. In this Review, these intracellular delivery strategies are discussed, briefly explaining the mechanisms and how they are used for live-cell labeling applications. Methods that are discussed include three biochemical agents that are used for this purpose-purpose-different nanocarriers, cell penetrating peptides and the pore-foraming bacterial toxin streptolysin O. Most successful intracellular label delivery methods are, however, based on physical principles to permeabilize the membrane and include electroporation, laser-induced photoporation, micro- and nanoinjection, nanoneedles or nanostraws, microfluidics, and nanomachines. The strengths and weaknesses of each strategy are discussed with a systematic comparison provided. Finally, the extrinsic probes that are reported for intracellular labeling so-far are summarized, together with the delivery strategies that are used and their performance. This combined information should provide for a useful guide for choosing the most suitable delivery method for the desired probes.
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Affiliation(s)
- Jing Liu
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent, B-9000, Belgium
| | - Juan C Fraire
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent, B-9000, Belgium
| | - Stefaan C De Smedt
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent, B-9000, Belgium
- Centre for Advanced Light Microscopy, Ghent University, Ghent, B-9000, Belgium
- Joint Laboratory of Advanced Biomedical Technology (NFU-UGent), College of Chemical Engineering, Nanjing Forestry University (NFU), Nanjing, 210037, P. R. China
| | - Ranhua Xiong
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent, B-9000, Belgium
| | - Kevin Braeckmans
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Ghent, B-9000, Belgium
- Centre for Advanced Light Microscopy, Ghent University, Ghent, B-9000, Belgium
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286
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Huber P. Targeting of the apical junctional complex by bacterial pathogens. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183237. [DOI: 10.1016/j.bbamem.2020.183237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 02/06/2020] [Accepted: 02/10/2020] [Indexed: 12/17/2022]
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287
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Peng W, Casey AK, Fernandez J, Carpinone EM, Servage KA, Chen Z, Li Y, Tomchick DR, Starai VJ, Orth K. A distinct inhibitory mechanism of the V-ATPase by Vibrio VopQ revealed by cryo-EM. Nat Struct Mol Biol 2020; 27:589-597. [PMID: 32424347 DOI: 10.1038/s41594-020-0429-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/01/2020] [Indexed: 12/18/2022]
Abstract
The Vibrio parahaemolyticus T3SS effector VopQ targets host-cell V-ATPase, resulting in blockage of autophagic flux and neutralization of acidic compartments. Here, we report the cryo-EM structure of VopQ bound to the Vo subcomplex of the V-ATPase. VopQ inserts into membranes and forms an unconventional pore while binding directly to subunit c of the V-ATPase membrane-embedded subcomplex Vo. We show that VopQ arrests yeast growth in vivo by targeting the immature Vo subcomplex in the endoplasmic reticulum (ER), thus providing insight into the observation that VopQ kills cells in the absence of a functional V-ATPase. VopQ is a bacterial effector that has been discovered to inhibit a host-membrane megadalton complex by coincidentally binding its target, inserting into a membrane and disrupting membrane potential. Collectively, our results reveal a mechanism by which bacterial effectors modulate host cell biology and provide an invaluable tool for future studies on V-ATPase-mediated membrane fusion and autophagy.
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Affiliation(s)
- Wei Peng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Amanda K Casey
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jessie Fernandez
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Kelly A Servage
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zhe Chen
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yang Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Diana R Tomchick
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vincent J Starai
- Department of Microbiology, University of Georgia, Athens, GA, USA
- Department of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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288
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Varadarajan V, Desikan R, Ayappa KG. Assessing the extent of the structural and dynamic modulation of membrane lipids due to pore forming toxins: insights from molecular dynamics simulations. SOFT MATTER 2020; 16:4840-4857. [PMID: 32421131 DOI: 10.1039/d0sm00086h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Infections caused by many virulent bacterial strains are triggered by the release of pore forming toxins (PFTs), which form oligomeric transmembrane pore complexes on the target plasma membrane. The spatial extent of the perturbation to the surrounding lipids during pore formation is relatively unexplored. Using all-atom molecular dynamics simulations, we investigate the changes in the structure and dynamics of lipids in a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayer in the presence of contrasting PFTs. Cytolysin A (ClyA), an α toxin with its inserted wedge shaped bundle of inserted α helices, induces significant asymmetry across the membrane leaflets in comparison with α hemolysin (AHL), a β toxin. Despite the differences in hydrophobic mismatch and uniquely different topologies of the two oligomers, perturbations to lipid order as reflected in the tilt angle and order parameters and membrane thinning are short ranged, lying within ∼2.5 nm from the periphery of either pore complex, and commensurate with distances typically associated with van der Waals forces. In contrast, the spatial extent of perturbations to the lipid dynamics extends outward to at least 4 nm for both proteins, and the continuous survival probabilities reveal the presence of a tightly bound shell of lipids in this region. Displacement probability distributions show long tails and the distinctly non-Gaussian features reflect the induced dynamic heterogeneity. A detailed profiling of the protein-lipid contacts with tyrosine, tryptophan, lysine and arginine residues shows increased non-polar contacts in the cytoplasmic leaflet for both PFTs, with a higher number of atomic contacts in the case of AHL in the extracellular leaflet due to the mushroom-like topology of the pore complex. The short ranged nature of the perturbations observed in this simple one component membrane suggests inherent plasticity of membrane lipids enabling the recovery of the structure and membrane fluidity even in the presence of these large oligomeric transmembrane protein assemblies. This observation has implications in membrane repair processes such as budding or vesicle fusion events used to mitigate PFT virulence, where the underlying lipid dynamics and fluidity in the vicinity of the pore complex are expected to play an important role.
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Affiliation(s)
- Vadhana Varadarajan
- Department of Chemical Engineering, Indian Institute of Science, Bangalore-560012, India.
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289
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The Cytocidal Spectrum of Bacillus thuringiensis Toxins: From Insects to Human Cancer Cells. Toxins (Basel) 2020; 12:toxins12050301. [PMID: 32384723 PMCID: PMC7291302 DOI: 10.3390/toxins12050301] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/27/2020] [Accepted: 05/02/2020] [Indexed: 12/29/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a ubiquitous bacterium in soils, insect cadavers, phylloplane, water, and stored grain, that produces several proteins, each one toxic to different biological targets such as insects, nematodes, mites, protozoa, and mammalian cells. Most Bt toxins identify their particular target through the recognition of specific cell membrane receptors. Cry proteins are the best-known toxins from Bt and a great amount of research has been published. Cry are cytotoxic to insect larvae that affect important crops recognizing specific cell membrane receptors such as cadherin, aminopeptidase-N, and alkaline phosphatase. Furthermore, some Cry toxins such as Cry4A, Cry4B, and Cry11A act synergistically with Cyt toxins against dipteran larvae vectors of human disease. Research developed with Cry proteins revealed that these toxins also could kill human cancer cells through the interaction with specific receptors. Parasporins are a small group of patented toxins that may or may not have insecticidal activity. These proteins could kill a wide variety of mammalian cancer cells by recognizing specific membrane receptors, just like Cry toxins do. Surface layer proteins (SLP), unlike the other proteins produced by Bt, are also produced by most bacteria and archaebacteria. It was recently demonstrated that SLP produced by Bt could interact with membrane receptors of insect and human cancer cells to kill them. Cyt toxins have a structure that is mostly unrelated to Cry toxins; thereby, other mechanisms of action have been reported to them. These toxins affect mainly mosquitoes that are vectors of human diseases like Anopheles spp (malaria), Aedes spp (dengue, zika, and chikungunya), and Culex spp (Nile fever and Rift Valley fever), respectively. In addition to the Cry, Cyt, and parasporins toxins produced during spore formation as inclusion bodies, Bt strains also produce Vip (Vegetative insecticidal toxins) and Sip (Secreted insecticidal proteins) toxins with insecticidal activity during their vegetative growth phase.
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290
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Sharma P, Rashid M, Kaur S. Novel enterocin E20c purified from Enterococcus hirae 20c synergised with ß-lactams and ciprofloxacin against Salmonella enterica. Microb Cell Fact 2020; 19:98. [PMID: 32366243 PMCID: PMC7197179 DOI: 10.1186/s12934-020-01352-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 04/15/2020] [Indexed: 02/06/2023] Open
Abstract
Background An increasing rate of antibiotic resistance among Gram-negative bacterial pathogens has created an urgent need to discover novel therapeutic agents to combat infectious diseases. Use of bacteriocins as therapeutic agents has immense potential due to their high potency and mode of action different from that of conventional antibiotics. Results In this study, a novel bacteriocin E20c of molecular weight 6.5 kDa was purified and characterized from the probiotic strain of Enterococcus hirae. E20c had bactericidal activities against several multidrug resistant (MDR) Gram-negative bacterial pathogens. Flow cytometry and scanning electron microscopy studies showed that it killed the Salmonella enterica cells by forming ion-permeable channels in the cell membrane leading to enhanced cell membrane permeability. Further, checkerboard titrations showed that E20c had synergistic interaction with antibiotics such as ampicillin, penicillin, ceftriaxone, and ciprofloxacin against a ciprofloxacin- and penicillin-resistant strain of S. enterica. Conclusion Thus, this study shows the broad spectrum antimicrobial activity of novel enterocin E20c against various MDR pathogens. Further, it highlights the importance of bacteriocins in lowering the minimum inhibitory concentrations of conventional antibiotics when used in combination.
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Affiliation(s)
- Preeti Sharma
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Muzamil Rashid
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Sukhraj Kaur
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab, India.
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291
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Liu J, Kozhaya L, Torres VJ, Unutmaz D, Lu M. Structure-based discovery of a small-molecule inhibitor of methicillin-resistant Staphylococcus aureus virulence. J Biol Chem 2020; 295:5944-5959. [PMID: 32179646 PMCID: PMC7196633 DOI: 10.1074/jbc.ra120.012697] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/06/2020] [Indexed: 01/07/2023] Open
Abstract
The rapid emergence and dissemination of methicillin-resistant Staphylococcus aureus (MRSA) strains poses a major threat to public health. MRSA possesses an arsenal of secreted host-damaging virulence factors that mediate pathogenicity and blunt immune defenses. Panton-Valentine leukocidin (PVL) and α-toxin are exotoxins that create lytic pores in the host cell membrane. They are recognized as being important for the development of invasive MRSA infections and are thus potential targets for antivirulence therapies. Here, we report the high-resolution X-ray crystal structures of both PVL and α-toxin in their soluble, monomeric, and oligomeric membrane-inserted pore states in complex with n-tetradecylphosphocholine (C14PC). The structures revealed two evolutionarily conserved phosphatidylcholine-binding mechanisms and their roles in modulating host cell attachment, oligomer assembly, and membrane perforation. Moreover, we demonstrate that the soluble C14PC compound protects primary human immune cells in vitro against cytolysis by PVL and α-toxin and hence may serve as the basis for the development of an antivirulence agent for managing MRSA infections.
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Affiliation(s)
- Jie Liu
- Public Health Research Institute, Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103
| | - Lina Kozhaya
- Jackson Laboratory for Genomic Medicine, Farmington, Connecticut 06032
| | - Victor J. Torres
- Department of Microbiology, New York University School of Medicine, New York, New York 10016
| | - Derya Unutmaz
- Jackson Laboratory for Genomic Medicine, Farmington, Connecticut 06032
| | - Min Lu
- Public Health Research Institute, Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103, To whom correspondence should be addressed:
Public Health Research Institute, Dept. of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Newark, NJ 07103. Tel.:
973-854-3260; E-mail:
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292
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Abstract
Immune cells use a variety of membrane-disrupting proteins [complement, perforin, perforin-2, granulysin, gasdermins, mixed lineage kinase domain-like pseudokinase (MLKL)] to induce different kinds of death of microbes and host cells, some of which cause inflammation. After activation by proteolytic cleavage or phosphorylation, these proteins oligomerize, bind to membrane lipids, and disrupt membrane integrity. These membrane disruptors play a critical role in both innate and adaptive immunity. Here we review our current knowledge of the functions, specificity, activation, and regulation of membrane-disrupting immune proteins and what is known about the mechanisms behind membrane damage, the structure of the pores they form, how the cells expressing these lethal proteins are protected, and how cells targeted for destruction can sometimes escape death by repairing membrane damage.
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Affiliation(s)
- Xing Liu
- Center for Microbes, Development and Health; Key Laboratory of Molecular Virology and Immunology; Institut Pasteur of Shanghai; Chinese Academy of Sciences, Shanghai 200031, China;
| | - Judy Lieberman
- Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA;
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293
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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294
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Kashimoto T, Sugiyama H, Kawamidori K, Yamazaki K, Kado T, Matsuda K, Kodama T, Mukai T, Ueno S. Vibiro vulnificus hemolysin associates with gangliosides. BMC Microbiol 2020; 20:69. [PMID: 32228455 PMCID: PMC7106661 DOI: 10.1186/s12866-020-01755-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 03/20/2020] [Indexed: 12/28/2022] Open
Abstract
Background Vibrio vulnificus hemolysin (VVH) is a pore-forming toxin secreted by Vibrio vulnificus. Cellular cholesterol was believed to be the receptor for VVH, because cholesterol could bind to VVH and preincubation with cholesterol inhibited cytotoxicity. It has been reported that specific glycans such as N-acetyl-D-galactosamine and N-acetyl-D-lactosamine bind to VVH, however, it has not been known whether these glycans could inhibit the cytotoxicity of VVH without oligomer formation. Thus, to date, binding mechanisms of VVH to cellular membrane, including specific receptors have not been elucidated. Results We show here that VVH associates with ganglioside GM1a, Fucosyl-GM1, GD1a, GT1c, and GD1b by glycan array. Among them, GM1a could pulldown VVH. Moreover, the GD1a inhibited the cytotoxicity of VVH without the formation of oligomers. Conclusion This is the first report of a molecule able to inhibit the binding of VVH to target cells without oligomerization of VVH.
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Affiliation(s)
- Takashige Kashimoto
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan.
| | - Hiroyuki Sugiyama
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Keigo Kawamidori
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Kohei Yamazaki
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Takehiro Kado
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Kaho Matsuda
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
| | - Toshio Kodama
- Department of Bacterial Infections, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Takao Mukai
- Laboratory of Biomolecular Science, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, Japan
| | - Shunji Ueno
- Laboratory of Veterinary Public Health, School of Veterinary Medicine and Animal Sciences, Kitasato University, Higashi 23-35-1, Towada, Aomori, 034-8628, Japan
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295
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Glutamine supports the protection of tissue cells against the damage caused by cholesterol-dependent cytolysins from pathogenic bacteria. PLoS One 2020; 15:e0219275. [PMID: 32163417 PMCID: PMC7067430 DOI: 10.1371/journal.pone.0219275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 02/21/2020] [Indexed: 12/28/2022] Open
Abstract
Pathogenic bacteria often damage tissues by secreting toxins that form pores in cell membranes, and the most common pore-forming toxins are cholesterol-dependent cytolysins. During bacterial infections, glutamine becomes a conditionally essential amino acid, and glutamine is an important nutrient for immune cells. However, the role of glutamine in protecting tissue cells against pore-forming toxins is unclear. Here we tested the hypothesis that glutamine supports the protection of tissue cells against the damage caused by cholesterol-dependent cytolysins. Stromal and epithelial cells were sensitive to damage by the cholesterol-dependent cytolysins, pyolysin and streptolysin O, as determined by leakage of potassium and lactate dehydrogenase from cells, and reduced cell viability. However, glutamine deprivation increased the leakage of lactate dehydrogenase and reduced the viability of cells challenged with cholesterol-dependent cytolysins. Without glutamine, stromal cells challenged with pyolysin leaked lactate dehydrogenase (control vs. pyolysin, 2.6 ± 0.6 vs. 34.4 ± 4.5 AU, n = 12), which was more than three-fold the leakage from cells supplied with 2 mM glutamine (control vs. pyolysin, 2.2 ± 0.3 vs. 9.4 ± 1.0 AU). Glutamine cytoprotection did not depend on glutaminolysis, replenishing the Krebs cycle via succinate, changes in cellular cholesterol, or regulators of cell metabolism (AMPK and mTOR). In conclusion, although the mechanism remains elusive, we found that glutamine supports the protection of tissue cells against the damage caused by cholesterol-dependent cytolysins from pathogenic bacteria.
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296
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Reply to Desikan et al.: Micelle formation among various mechanisms of toxin pore formation. Proc Natl Acad Sci U S A 2020; 117:5109-5110. [PMID: 32098852 PMCID: PMC7071846 DOI: 10.1073/pnas.1922488117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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297
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Jin F. Structural insights into the mechanism of a novel protein targeting pathway in Gram-negative bacteria. FEBS Open Bio 2020; 10:561-579. [PMID: 32068344 PMCID: PMC7137807 DOI: 10.1002/2211-5463.12813] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 02/05/2020] [Accepted: 02/16/2020] [Indexed: 12/02/2022] Open
Abstract
Many nascent polypeptides synthesized in the cytoplasm are translocated across membranes via a specific ‘translocon’ composed of protein complexes. Recently, a novel targeting pathway for the outer membrane β‐barrel proteins (OMPs) in Gram‐negative bacteria was discovered. The cell envelope of Gram‐negative bacteria is composed of the inner (plasma) membrane (IM) and the outer membrane (OM). In this new pathway, a SecAN protein, which is mainly present in the IM as a homo‐oligomer, translocates nascent OMPs across the IM; at the same time, SecAN directly interacts with the β‐barrel assembly machinery (BAM) complex embedded within the OM. A supercomplex (containing SecAN, the BAM complex and many other proteins) spans the IM and OM, and is involved in the biogenesis of OMPs. Investigation of the function of SecAN and the supercomplex, as well as the translocation mechanism, will require elucidation of their structures. However, no such structures are available. Therefore, here, I describe the use of protein modeling to build homology models for SecAN and theoretical structures for the core‐complex composed of SecAN and the BAM complex, which is a key part of the supercomplex. The modeling data are consistent with previous experimental observations and demonstrated a conformational change of the core‐complex. I conclude by proposing mechanisms for how SecAN and the supercomplex function in the biogenesis of OMPs.
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Affiliation(s)
- Feng Jin
- School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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298
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Keller MD, Ching KL, Liang FX, Dhabaria A, Tam K, Ueberheide BM, Unutmaz D, Torres VJ, Cadwell K. Decoy exosomes provide protection against bacterial toxins. Nature 2020; 579:260-264. [PMID: 32132711 DOI: 10.1038/s41586-020-2066-6] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/09/2020] [Indexed: 12/13/2022]
Abstract
The production of pore-forming toxins that disrupt the plasma membrane of host cells is a common virulence strategy for bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA)1-3. It is unclear, however, whether host species possess innate immune mechanisms that can neutralize pore-forming toxins during infection. We previously showed that the autophagy protein ATG16L1 is necessary for protection against MRSA strains encoding α-toxin4-a pore-forming toxin that binds the metalloprotease ADAM10 on the surface of a broad range of target cells and tissues2,5,6. Autophagy typically involves the targeting of cytosolic material to the lysosome for degradation. Here we demonstrate that ATG16L1 and other ATG proteins mediate protection against α-toxin through the release of ADAM10 on exosomes-extracellular vesicles of endosomal origin. Bacterial DNA and CpG DNA induce the secretion of ADAM10-bearing exosomes from human cells as well as in mice. Transferred exosomes protect host cells in vitro by serving as scavengers that can bind multiple toxins, and improve the survival of mice infected with MRSA in vivo. These findings indicate that ATG proteins mediate a previously unknown form of defence in response to infection, facilitating the release of exosomes that serve as decoys for bacterially produced toxins.
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Affiliation(s)
- Matthew D Keller
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.,Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY, USA
| | - Krystal L Ching
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.,Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY, USA
| | - Feng-Xia Liang
- Division of Advanced Research Technologies, New York University Langone Health, New York, NY, USA.,The Microscopy Labratory at New York University Langone Health, New York, NY, USA
| | - Avantika Dhabaria
- Division of Advanced Research Technologies, New York University Langone Health, New York, NY, USA.,The Proteomics Labratory at New York University Langone Health, New York, NY, USA
| | - Kayan Tam
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Beatrix M Ueberheide
- Division of Advanced Research Technologies, New York University Langone Health, New York, NY, USA.,The Proteomics Labratory at New York University Langone Health, New York, NY, USA.,The Laura and Isaac Perlmutter Cancer Center, New York, NY, USA
| | - Derya Unutmaz
- Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.
| | - Ken Cadwell
- Department of Microbiology, New York University School of Medicine, New York, NY, USA. .,Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, NY, USA. .,Division of Gastroenterology and Hepatology, Department of Medicine, New York University Langone Health, New York, NY, USA.
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299
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Mehdizadeh Gohari I, Unterer S, Whitehead AE, Prescott JF. NetF-producing Clostridium perfringens and its associated diseases in dogs and foals. J Vet Diagn Invest 2020; 32:230-238. [PMID: 32081091 PMCID: PMC7081511 DOI: 10.1177/1040638720904714] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The role of type A Clostridium perfringens in canine acute hemorrhagic diarrhea syndrome and foal necrotizing enteritis is poorly characterized. However, a highly significant association between the presence of novel toxigenic C. perfringens and these specific enteric diseases has been described. These novel toxigenic strains produce 3 novel putative toxins, which have been designated NetE, NetF, and NetG. Although not conclusively demonstrated, current evidence suggests that NetF is likely the major virulence factor in strains responsible for canine acute hemorrhagic diarrhea syndrome and foal necrotizing enteritis. NetF is a beta-pore-forming toxin that belongs to the same toxin superfamily as CPB and NetB toxins produced by C. perfringens. The netF gene is encoded on a conjugative plasmid that, in the case of netF, also carries another putative toxin gene, netE. In addition, these strains consistently also carry a cpe tcp-conjugative plasmid, and a proportion also carry a separate netG tcp-conjugative plasmid. The netF and netG genes form part of a locus with all the features of the pathogenicity loci of tcp-conjugative plasmids. The netF-positive isolates are clonal in origin and fall into 2 clades. Disease in dogs or foals can be associated with either clade. Thus, these are strains with unique virulence-associated characteristics associated with serious and sometimes fatal cases of important enteric diseases in 2 animal species.
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Affiliation(s)
- Iman Mehdizadeh Gohari
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA (Mehdizadeh Gohari)
- Department of Clinical Veterinary Medicine, Clinic of Small Animal Internal Medicine, Ludwig Maximilian University of Munich, Munich, Germany (Unterer)
- Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, Canada (Whitehead)
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada (Prescott)
| | - Stefan Unterer
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA (Mehdizadeh Gohari)
- Department of Clinical Veterinary Medicine, Clinic of Small Animal Internal Medicine, Ludwig Maximilian University of Munich, Munich, Germany (Unterer)
- Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, Canada (Whitehead)
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada (Prescott)
| | - Ashley E Whitehead
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA (Mehdizadeh Gohari)
- Department of Clinical Veterinary Medicine, Clinic of Small Animal Internal Medicine, Ludwig Maximilian University of Munich, Munich, Germany (Unterer)
- Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, Canada (Whitehead)
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada (Prescott)
| | - John F Prescott
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA (Mehdizadeh Gohari)
- Department of Clinical Veterinary Medicine, Clinic of Small Animal Internal Medicine, Ludwig Maximilian University of Munich, Munich, Germany (Unterer)
- Department of Veterinary Clinical and Diagnostic Sciences, University of Calgary, Calgary, Alberta, Canada (Whitehead)
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada (Prescott)
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Cao B, Shu C, Geng L, Song F, Zhang J. Cry78Ba1, One Novel Crystal Protein from Bacillus thuringiensis with High Insecticidal Activity against Rice Planthopper. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:2539-2546. [PMID: 32023056 DOI: 10.1021/acs.jafc.9b07429] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The rice planthopper is a very important hemipteran pest that preys on rice and substantially affects the safety of rice production. Moreover, the long-term prevention and control of these pests with chemical pesticides has led to an increase in the resistance of the rice planthopper as well as serious environmental pollution and food safety problems. Bacillus thuringiensis (Bt) has been used for the efficient and green control of a variety of rice pests. Therefore, based on the high-throughput screening of Bt strains that are active against the rice planthopper, we found that Bt strain B4F11 showed certain insecticidal activity against Laodelphax striatellus Fallén, and we have identified a novel insecticidal protein Cry78Ba1 from the Bt strain B4F11, which is expected to provide the specific and safe control of the rice planthopper. The Cry78Ba1 protein is composed of 380 amino acid residues with a molecular weight of 42.55 kDa and contains conserved Ricin_B_Lectin and Toxin_10 superfamily domains. It displays high insecticidal activity against L. striatellus with a lethal concentration (LC50) of 9.723 μg/mL. More importantly, this Toxin_10-like protein does not display sequence homology to any known allergen and can be degraded and inactivated rapidly when heated at 90 °C and in simulated gastrointestinal fluid. In summary, Cry78Ba1 has great potential for applications in the efficient and safe prevention and control of the rice planthopper.
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Affiliation(s)
- Beibei Cao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Fuping Song
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection , Chinese Academy of Agricultural Sciences , Beijing 100193 , People's Republic of China
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