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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: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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302
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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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303
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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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304
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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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305
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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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306
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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: 146] [Impact Index Per Article: 36.5] [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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307
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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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308
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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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309
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310
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Omersa N, Aden S, Kisovec M, Podobnik M, Anderluh G. Design of Protein Logic Gate System Operating on Lipid Membranes. ACS Synth Biol 2020; 9:316-328. [PMID: 31995709 PMCID: PMC7308068 DOI: 10.1021/acssynbio.9b00340] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Indexed: 12/16/2022]
Abstract
Lipid membranes are becoming increasingly popular in synthetic biology due to their biophysical properties and crucial role in communication between different compartments. Several alluring protein-membrane sensors have already been developed, whereas protein logic gates designs on membrane-embedded proteins are very limited. Here we demonstrate the construction of a two-level protein-membrane logic gate with an OR-AND logic. The system consists of an engineered pH-dependent pore-forming protein listeriolysin O and its DARPin-based inhibitor, conjugated to a lipid vesicle membrane. The gate responds to low pH and removal of the inhibitor from the membrane either by switching to a reducing environment, protease cleavage, or any other signal depending on the conjugation chemistry used for inhibitor attachment to the membrane. This unique protein logic gate vesicle system advances generic sensing and actuator platforms used in synthetic biology and could be utilized in drug delivery.
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Affiliation(s)
- Neža Omersa
- Department
of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova ulica 19, 1001 Ljubljana, Slovenia
- Biomedicine
Doctoral Program, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
| | - Saša Aden
- Department
of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova ulica 19, 1001 Ljubljana, Slovenia
- Biomedicine
Doctoral Program, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia
| | - Matic Kisovec
- Department
of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova ulica 19, 1001 Ljubljana, Slovenia
| | - Marjetka Podobnik
- Department
of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova ulica 19, 1001 Ljubljana, Slovenia
| | - Gregor Anderluh
- Department
of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova ulica 19, 1001 Ljubljana, Slovenia
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311
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von Hoven G, Qin Q, Neukirch C, Husmann M, Hellmann N. Staphylococcus aureus α-toxin: small pore, large consequences. Biol Chem 2020; 400:1261-1276. [PMID: 30951494 DOI: 10.1515/hsz-2018-0472] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/26/2019] [Indexed: 12/14/2022]
Abstract
The small β-pore-forming α-toxin, also termed α-hemolysin or Hla is considered to be an important virulence factor of Staphylococcus aureus. Perforation of the plasma membrane (PM) by Hla leads to uncontrolled flux of ions and water. Already a small number of toxin pores seems to be sufficient to induce complex cellular responses, many of which depend on the efflux of potassium. In this article, we discuss the implications of secondary membrane lesions, for example, by endogenous channels, for Hla-mediated toxicity, for calcium-influx and membrane repair. Activation of purinergic receptors has been proposed to be a major contributor to the lytic effects of various pore forming proteins, but new findings raise doubts that this holds true for Hla. However, the recently discovered cellular pore forming proteins gasdermin D and Mixed lineage kinase domain-like pseudokinase (MLKL) which perforate the PM from the cytosolic side might contribute to both calcium-influx-dependent damage and membrane repair. Activation of endogenous pore forming proteins by Hla above a threshold concentration could explain the apparent dependence of pore characteristics on toxin concentrations. If secondary membrane damage in the aftermath of Hla-attack contributes significantly to overall PM permeability, it might be an interesting target for new therapeutic approaches.
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Affiliation(s)
- Gisela von Hoven
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Qianqian Qin
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Claudia Neukirch
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Matthias Husmann
- Institute of Medical Microbiology and Hygiene, University Medical Center of the Johannes Gutenberg-University Mainz, Obere Zahlbacher Straße 67, 55131 Mainz, Germany
| | - Nadja Hellmann
- Institute for Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim Becher-Weg 30, 55128 Mainz, Germany
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312
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Fox D, Mathur A, Xue Y, Liu Y, Tan WH, Feng S, Pandey A, Ngo C, Hayward JA, Atmosukarto II, Price JD, Johnson MD, Jessberger N, Robertson AAB, Burgio G, Tscharke DC, Fox EM, Leyton DL, Kaakoush NO, Märtlbauer E, Leppla SH, Man SM. Bacillus cereus non-haemolytic enterotoxin activates the NLRP3 inflammasome. Nat Commun 2020; 11:760. [PMID: 32029733 PMCID: PMC7005308 DOI: 10.1038/s41467-020-14534-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 01/14/2020] [Indexed: 02/07/2023] Open
Abstract
Inflammasomes are important for host defence against pathogens and homeostasis with commensal microbes. Here, we show non-haemolytic enterotoxin (NHE) from the neglected human foodborne pathogen Bacillus cereus is an activator of the NLRP3 inflammasome and pyroptosis. NHE is a non-redundant toxin to haemolysin BL (HBL) despite having a similar mechanism of action. Via a putative transmembrane region, subunit C of NHE initiates binding to the plasma membrane, leading to the recruitment of subunit B and subunit A, thus forming a tripartite lytic pore that is permissive to efflux of potassium. NHE mediates killing of cells from multiple lineages and hosts, highlighting a versatile functional repertoire in different host species. These data indicate that NHE and HBL operate synergistically to induce inflammation and show that multiple virulence factors from the same pathogen with conserved function and mechanism of action can be exploited for sensing by a single inflammasome.
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Affiliation(s)
- Daniel Fox
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Anukriti Mathur
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Yansong Xue
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Yunqi Liu
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Wei Hong Tan
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Shouya Feng
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Abhimanu Pandey
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Chinh Ngo
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Jenni A Hayward
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Ines I Atmosukarto
- Lipotek Pty Ltd. The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Jason D Price
- Lipotek Pty Ltd. The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Matthew D Johnson
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Nadja Jessberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
| | - Avril A B Robertson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Gaetan Burgio
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - David C Tscharke
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Edward M Fox
- Department of Applied Sciences, Northumbria University, Newcastle Upon Tyne, UK
| | - Denisse L Leyton
- Research School of Biology, The Australian National University, Canberra, Australia.,Medical School, The Australian National University, Canberra, Australia
| | - Nadeem O Kaakoush
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim, Germany
| | - 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
| | - Si Ming Man
- Department of Immunology and Infectious Disease, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
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313
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Cohen H, Baram N, Edry-Botzer L, Munitz A, Salomon D, Gerlic M. Vibrio pore-forming leukocidin activates pyroptotic cell death via the NLRP3 inflammasome. Emerg Microbes Infect 2020; 9:278-290. [PMID: 32013758 PMCID: PMC7034064 DOI: 10.1080/22221751.2020.1720526] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cell death mechanisms are central to combat infections and to drive inflammation. The inflammasome controls infection through activation of caspase-1 leading to either IL-1β dependent inflammation, or pyroptotic cell death in infected cells. Hemolysins, which are pore-forming toxins (PFTs), alter the permeability of the host target membrane, often leading to cell death. We previously discovered a leukocidin domain-containing PFT produced by the Gram-negative bacterium Vibrio proteolyticus, named VPRH. VPRH constitutes a distinct, understudied class within the leukocidin superfamily, which is distributed among several photogenic Vibrios. Since PFTs of other pathogens were shown to activate the inflammasome pathway, we hypothesized that VPRH-induced cell death is mediated by direct activation of the inflammasome in mammalian immune host cells. Indeed, we found that VPRH induced a two-step cell death in macrophages. The first, a rapid step, was mediated by activating the NLRP3 inflammasome, leading to caspase-1 activation that resulted in IL-1β secretion and pyroptosis. The second step was independent of the inflammasome; however, its mechanism remains unknown. This study sets the foundation for better understanding the immunological consequences of inflammasome activation by a new leukocidin class of toxins, which may be shared between marine bacteria and give rise to new pathogenic isolates.
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Affiliation(s)
- Hadar Cohen
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Noam Baram
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liat Edry-Botzer
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ariel Munitz
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dor Salomon
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Motti Gerlic
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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314
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Desikan R, Maiti PK, Ayappa KG. Predicting interfacial hot-spot residues that stabilize protein-protein interfaces in oligomeric membrane-toxin pores through hydrogen bonds and salt bridges. J Biomol Struct Dyn 2020; 39:20-34. [DOI: 10.1080/07391102.2020.1711806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Rajat Desikan
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, India
| | - Prabal K. Maiti
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India
| | - K. Ganapathy Ayappa
- Department of Chemical Engineering, Indian Institute of Science, Bangalore, India
- Centre for Biosystems Science and Engineering, Indian Institute of Science, Bangalore, India
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315
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Pleckaityte M. Cholesterol-Dependent Cytolysins Produced by Vaginal Bacteria: Certainties and Controversies. Front Cell Infect Microbiol 2020; 9:452. [PMID: 31998661 PMCID: PMC6966277 DOI: 10.3389/fcimb.2019.00452] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/12/2019] [Indexed: 01/16/2023] Open
Abstract
Bacterial vaginosis (BV) is a vaginal anaerobic dysbiosis that affects women of reproductive age worldwide. BV is microbiologically characterized by the depletion of vaginal lactobacilli and the overgrowth of anaerobic bacterial species. Accumulated evidence suggests that Gardnerella spp. have a pivotal role among BV-associated bacteria in the initiation and development of BV. However, Gardnerella spp. often colonize healthy women. Lactobacillus iners is considered as a prevalent constituent of healthy vaginal microbiota, and is abundant in BV. Gardnerella spp. and L. iners secrete the toxins vaginolysin (VLY) and inerolysin (INY), which have structural and activity features attributed to cholesterol-dependent cytolysins (CDCs). CDCs are produced by many pathogenic bacteria as virulence factors that participate in various stages of disease progression by forming lytic and non-lytic pores in cell membranes or via pore-independent pathways. VLY is expressed in the majority of Gardnerella spp. isolates; less is known about the prevalence of the gene that encodes INY. INY is a classical CDC; membrane cholesterol acts a receptor for INY. VLY uses human CD59 as its receptor, although cholesterol remains indispensable for VLY pore-forming activity. INY-induced damage of artificial membranes is directly dependent on cholesterol concentration in the bilayer, whereas VLY-induced damage occurs with high levels of membrane cholesterol (>40 mol%). VLY primarily forms membrane-embedded complete rings in the synthetic bilayer, whereas INY forms arciform structures with smaller pore sizes. VLY activity is high at elevated pH, which is characteristic of BV, whereas INY activity is high at more acidic pH, which is specific for a healthy vagina. Increased VLY levels in vaginal mucosa in vivo were associated with clinical indicators of BV. However, experimental evidence is lacking for the specific roles of VLY and INY in BV. The interplay between vaginal bacterial species affects the expression of the gene encoding VLY, thereby modulating the virulence of Gardnerella spp. This review discusses the current evidence for VLY and INY cytolysins, including their structures and activities, factors affecting their expression, and their potential impacts on the progression of anaerobic dysbiosis.
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Affiliation(s)
- Milda Pleckaityte
- Laboratory of Immunology and Cell Biology, Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
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316
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Chen L, Liang S, Chen Y, Wu M, Zhang Y. Destructing the Plasma Membrane with Activatable Vesicular DNA Nanopores. ACS APPLIED MATERIALS & INTERFACES 2020; 12:96-105. [PMID: 31815409 DOI: 10.1021/acsami.9b14746] [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: 06/10/2023]
Abstract
Pore-forming proteins are an agent for attack or defense in various organisms, and its cytolytic activity has medical potential in cancer therapy. Despite recent advances in mimicking these proteins by amphipathic DNA nanopores, it remains inefficient to incorporate them into lipid bilayers. Here, we present the development of vesicular DNA nanopores that can controllably open a lipid membrane. Different from previously reported DNA nanopores that randomly insert into the planar bilayers, we design on-command fusogenic liposome-incorporated transmembrane DNA nanopores (FLIPs) that bypass the direct insertion process. By steric deshielding of fusogenic liposomal supports under low pH conditions, the embedded FLIPs are transferred and perforate lipid bilayers. We find that FLIPs depolarize the plasma membrane and thereby induce pyroptosis-like cell death. We further demonstrate the use of FLIPs to inhibit tumor growth in murine tumor models, which provides a new route to cancer nanotherapy.
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Affiliation(s)
- Liang Chen
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , P. R. China
| | - Siping Liang
- Zhongshan School of Medicine , Sun Yat-sen University , Guangzhou 510080 , P. R. China
| | - Yu Chen
- Zhongshan School of Medicine , Sun Yat-sen University , Guangzhou 510080 , P. R. China
| | - Minhao Wu
- Zhongshan School of Medicine , Sun Yat-sen University , Guangzhou 510080 , P. R. China
| | - Yuanqing Zhang
- School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou 510006 , P. R. China
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317
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Pore-forming toxins from sea anemones: from protein-membrane interaction to its implications for developing biomedical applications. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2020. [DOI: 10.1016/bs.abl.2020.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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318
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Shah J, Rouaud F, Guerrera D, Vasileva E, Popov LM, Kelley WL, Rubinstein E, Carette JE, Amieva MR, Citi S. A Dock-and-Lock Mechanism Clusters ADAM10 at Cell-Cell Junctions to Promote α-Toxin Cytotoxicity. Cell Rep 2019; 25:2132-2147.e7. [PMID: 30463011 DOI: 10.1016/j.celrep.2018.10.088] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 10/01/2018] [Accepted: 10/24/2018] [Indexed: 01/08/2023] Open
Abstract
We previously identified PLEKHA7 and other junctional proteins as host factors mediating death by S. aureus α-toxin, but the mechanism through which junctions promote toxicity was unclear. Using cell biological and biochemical methods, we now show that ADAM10 is docked to junctions by its transmembrane partner Tspan33, whose cytoplasmic C terminus binds to the WW domain of PLEKHA7 in the presence of PDZD11. ADAM10 is locked at junctions through binding of its cytoplasmic C terminus to afadin. Junctionally clustered ADAM10 supports the efficient formation of stable toxin pores. Instead, disruption of the PLEKHA7-PDZD11 complex inhibits ADAM10 and toxin junctional clustering. This promotes toxin pore removal from the cell surface through an actin- and macropinocytosis-dependent process, resulting in cell recovery from initial injury and survival. These results uncover a dock-and-lock molecular mechanism to target ADAM10 to junctions and provide a paradigm for how junctions regulate transmembrane receptors through their clustering.
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Affiliation(s)
- Jimit Shah
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Florian Rouaud
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Diego Guerrera
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Ekaterina Vasileva
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland
| | - Lauren M Popov
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - William L Kelley
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, 1211-4 Geneva, Switzerland
| | - Eric Rubinstein
- INSERM, Université Paris-Sud, UMRS_935, 94807 Villejuif Cedex, France
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Manuel R Amieva
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sandra Citi
- Department of Cell Biology, Faculty of Sciences, University of Geneva, 1211-4 Geneva, Switzerland; Institute for Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland.
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319
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Larpin Y, Besançon H, Iacovache MI, Babiychuk VS, Babiychuk EB, Zuber B, Draeger A, Köffel R. Bacterial pore-forming toxin pneumolysin: Cell membrane structure and microvesicle shedding capacity determines differential survival of cell types. FASEB J 2019; 34:1665-1678. [PMID: 31914676 DOI: 10.1096/fj.201901737rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/14/2019] [Accepted: 11/06/2019] [Indexed: 12/25/2022]
Abstract
Bacterial infectious diseases can lead to death or to serious illnesses. These outcomes are partly the consequence of pore-forming toxins, which are secreted by the pathogenic bacteria (eg, pneumolysin of Streptococcus pneumoniae). Pneumolysin binds to cholesterol within the plasma membrane of host cells and assembles to form trans-membrane pores, which can lead to Ca2+ influx and cell death. Membrane repair mechanisms exist that limit the extent of damage. Immune cells which are essential to fight bacterial infections critically rely on survival mechanisms after detrimental pneumolysin attacks. This study investigated the susceptibility of different immune cell types to pneumolysin. As a model system, we used the lymphoid T-cell line Jurkat, and myeloid cell lines U937 and THP-1. We show that Jurkat T cells are highly susceptible to pneumolysin attack. In contrast, myeloid THP-1 and U937 cells are less susceptible to pneumolysin. In line with these findings, human primary T cells are shown to be more susceptible to pneumolysin attack than monocytes. Differences in susceptibility to pneumolysin are due to (I) preferential binding of pneumolysin to Jurkat T cells and (II) cell type specific plasma membrane repair capacity. Myeloid cell survival is mostly dependent on Ca2+ induced expelling of damaged plasma membrane areas as microvesicles. Thus, in myeloid cells, first-line defense cells in bacterial infections, a potent cellular repair machinery ensures cell survival after pneumolysin attack. In lymphoid cells, which are important at later stages of infections, less efficient repair mechanisms and enhanced toxin binding renders the cells more sensitive to pneumolysin.
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Affiliation(s)
- Yu Larpin
- Department of Cell Biology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Hervé Besançon
- Department of Cell Biology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Mircea-Ioan Iacovache
- Laboratory of Experimental Morphology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Victoriia S Babiychuk
- Department of Cell Biology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Eduard B Babiychuk
- Department of Cell Biology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Benoît Zuber
- Laboratory of Experimental Morphology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Annette Draeger
- Department of Cell Biology, Institute of Anatomy, University of Bern, Bern, Switzerland
| | - René Köffel
- Department of Cell Biology, Institute of Anatomy, University of Bern, Bern, Switzerland
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320
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Mariano G, Trunk K, Williams DJ, Monlezun L, Strahl H, Pitt SJ, Coulthurst SJ. A family of Type VI secretion system effector proteins that form ion-selective pores. Nat Commun 2019; 10:5484. [PMID: 31792213 PMCID: PMC6889166 DOI: 10.1038/s41467-019-13439-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/05/2019] [Indexed: 12/25/2022] Open
Abstract
Type VI secretion systems (T6SSs) are nanomachines widely used by bacteria to deliver toxic effector proteins directly into neighbouring cells. However, the modes of action of many effectors remain unknown. Here we report that Ssp6, an anti-bacterial effector delivered by a T6SS of the opportunistic pathogen Serratia marcescens, is a toxin that forms ion-selective pores. Ssp6 inhibits bacterial growth by causing depolarisation of the inner membrane in intoxicated cells, together with increased outer membrane permeability. Reconstruction of Ssp6 activity in vitro demonstrates that it forms cation-selective pores. A survey of bacterial genomes reveals that genes encoding Ssp6-like effectors are widespread in Enterobacteriaceae and often linked with T6SS genes. We conclude that Ssp6 and similar proteins represent a new family of T6SS-delivered anti-bacterial effectors.
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Affiliation(s)
- Giuseppina Mariano
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow St, Dundee, DD1 5EH, UK
| | - Katharina Trunk
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow St, Dundee, DD1 5EH, UK
| | - David J Williams
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow St, Dundee, DD1 5EH, UK
| | - Laura Monlezun
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow St, Dundee, DD1 5EH, UK
| | - Henrik Strahl
- Centre for Bacterial Cell Biology, Newcastle University, Richardson Road, Newcastle-upon-Tyne, NE2 4AX, UK
| | - Samantha J Pitt
- School of Medicine, University of St Andrews, North Haugh, St Andrews, KY16 9TF, UK
| | - Sarah J Coulthurst
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dow St, Dundee, DD1 5EH, UK.
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321
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Rantapää Dahlqvist S, Andrade F. Individuals at risk of seropositive rheumatoid arthritis: the evolving story. J Intern Med 2019; 286:627-643. [PMID: 31562671 PMCID: PMC6878216 DOI: 10.1111/joim.12980] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aetiology of the autoimmune disease rheumatoid arthritis (RA) involves a complex interplay between genetic and environmental factors that initiate many years before the onset of clinical symptoms. These interactions likely include both protective and susceptibility factors which together determine the risk of developing RA. More than 100 susceptibility loci have been linked to RA. The strongest association is with HLA-DRB1 alleles encoding antigen presenting molecules containing a unique sequence in the peptide-binding grove called the 'shared epitope'. Female sex, infections during childhood, lifestyle habits (e.g. smoking and diet) and distinct microbial agents, amongst many others, are interacting risk factors thought to contribute to RA pathogenesis by dysregulating the immune system in individuals with genetic susceptibility. Interestingly, patients with RA develop autoantibodies many years before the clinical onset of disease, providing strong evidence that the lack of tolerance to arthritogenic antigens is amongst the earliest events in the initiation of seropositive RA. Here, we will discuss the clinical and mechanistic evidence surrounding the role of different environmental and genetic factors in the phases leading to the production of autoantibodies and the initiation of symptomatic RA. Understanding this complexity is critical in order to develop tools to identify drivers of disease initiation and propagation and to develop preventive therapeutics.
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Affiliation(s)
- S Rantapää Dahlqvist
- Institution of Public Health and Clinical Medicine/Rheumatology, Umeå University, Umeå, Sweden
| | - F Andrade
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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322
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Tarun OB, Eremchev MY, Radenovic A, Roke S. Spatiotemporal Imaging of Water in Operating Voltage-Gated Ion Channels Reveals the Slow Motion of Interfacial Ions. NANO LETTERS 2019; 19:7608-7613. [PMID: 31580677 DOI: 10.1021/acs.nanolett.9b02024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ion channels are responsible for numerous physiological functions ranging from transport to chemical and electrical signaling. Although static ion channel structure has been studied following a structural biology approach, spatiotemporal investigation of the dynamic molecular mechanisms of operational ion channels has not been achieved experimentally. In particular, the role of water remains elusive. Here, we perform label-free spatiotemporal second harmonic (SH) imaging and capacitance measurements of operational voltage-gated alamethicin ion channels in freestanding lipid membranes surrounded by aqueous solution on either side. We observe changes in SH intensity upon channel activation that are traced back to changes in the orientational distribution of water molecules that reorient along the field lines of transported ions. Of the transported ions, a fraction of 10-4 arrives at the hydrated membrane interface, leading to interfacial electrostatic changes on the time scale of a second. The time scale of these interfacial changes is influenced by the density of ion channels and is subject to a crowding mechanism. Ion transport along cell membranes is often associated with the propagation of electrical signals in neurons. As our study shows that this process is taking place over seconds, a more complex mechanism is likely responsible for the propagation of neuronal electrical signals than just the millisecond movement of ions.
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Affiliation(s)
- Orly B Tarun
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS) , École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
| | - Maksim Yu Eremchev
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS) , École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
| | - Aleksandra Radenovic
- Laboratory of Nanoscale Biology, Institute of Bioengineering (IBI), School of Engineering (STI) , EPFL , CH-1015 Lausanne , Switzerland
| | - Sylvie Roke
- Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Materials Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS) , École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne , Switzerland
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323
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Kobayashi M, Nishimura M, Kawamura M, Kamemura N, Nagamune H, Tabata A. Change in membrane potential induced by streptolysin O, a pore‐forming toxin: flow cytometric analysis using a voltage‐sensitive fluorescent probe and rat thymic lymphocytes. Microbiol Immunol 2019; 64:10-22. [DOI: 10.1111/1348-0421.12748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/23/2019] [Accepted: 09/29/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Miho Kobayashi
- Department of Biological Science and Technology, Graduate School of Advanced Technology and ScienceTokushima UniversityTokushima Tokushima Japan
| | - Madoka Nishimura
- Department of Biological Science and Technology, Faculty of EngineeringTokushima UniversityTokushima Tokushima Japan
| | - Mina Kawamura
- Department of Bioscience and Bioindustry, Faculty of Bioscience and BioindustryTokushima UniversityTokushima Tokushima Japan
| | - Norio Kamemura
- Department of Food‐Nutritional Sciences, Faculty of Life SciencesTokushima Bunri UniversityTokushima Tokushima Japan
| | - Hideaki Nagamune
- Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social SciencesTokushima UniversityTokushima Tokushima Japan
| | - Atsushi Tabata
- Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social SciencesTokushima UniversityTokushima Tokushima Japan
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324
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Structural Insight of Gasdermin Family Driving Pyroptotic Cell Death. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1172:189-205. [DOI: 10.1007/978-981-13-9367-9_9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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325
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van Thiel IAM, Botschuijver S, de Jonge WJ, Seppen J. Painful interactions: Microbial compounds and visceral pain. Biochim Biophys Acta Mol Basis Dis 2019; 1866:165534. [PMID: 31634534 DOI: 10.1016/j.bbadis.2019.165534] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 12/18/2022]
Abstract
Visceral pain, characterized by abdominal discomfort, originates from organs in the abdominal cavity and is a characteristic symptom in patients suffering from irritable bowel syndrome, vulvodynia or interstitial cystitis. Most organs in which visceral pain originates are in contact with the external milieu and continuously exposed to microbes. In order to maintain homeostasis and prevent infections, the immune- and nervous system in these organs cooperate to sense and eliminate (harmful) microbes. Recognition of microbial components or products by receptors expressed on cells from the immune and nervous system can activate immune responses but may also cause pain. We review the microbial compounds and their receptors that could be involved in visceral pain development.
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Affiliation(s)
- I A M van Thiel
- Tytgat Institute for Liver and Intestinal Research, Amsterdam UMC, location AMC, Meibergdreef 69, 1105 BK Amsterdam, the Netherlands
| | - S Botschuijver
- Tytgat Institute for Liver and Intestinal Research, Amsterdam UMC, location AMC, Meibergdreef 69, 1105 BK Amsterdam, the Netherlands
| | - W J de Jonge
- Tytgat Institute for Liver and Intestinal Research, Amsterdam UMC, location AMC, Meibergdreef 69, 1105 BK Amsterdam, the Netherlands
| | - J Seppen
- Tytgat Institute for Liver and Intestinal Research, Amsterdam UMC, location AMC, Meibergdreef 69, 1105 BK Amsterdam, the Netherlands.
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326
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Mondal AK, Chattopadhyay K. Taking Toll on Membranes: Curious Cases of Bacterial β-Barrel Pore-Forming Toxins. Biochemistry 2019; 59:163-170. [DOI: 10.1021/acs.biochem.9b00783] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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, SAS 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, SAS Nagar, Manauli, Mohali, Punjab 140306, India
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327
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Duport C, Alpha-Bazin B, Armengaud J. Advanced Proteomics as a Powerful Tool for Studying Toxins of Human Bacterial Pathogens. Toxins (Basel) 2019; 11:toxins11100576. [PMID: 31590258 PMCID: PMC6832400 DOI: 10.3390/toxins11100576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 12/15/2022] Open
Abstract
Exotoxins contribute to the infectious processes of many bacterial pathogens, mainly by causing host tissue damages. The production of exotoxins varies according to the bacterial species. Recent advances in proteomics revealed that pathogenic bacteria are capable of simultaneously producing more than a dozen exotoxins. Interestingly, these toxins may be subject to post-transcriptional modifications in response to environmental conditions. In this review, we give an outline of different bacterial exotoxins and their mechanism of action. We also report how proteomics contributed to immense progress in the study of toxinogenic potential of pathogenic bacteria over the last two decades.
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Affiliation(s)
- Catherine Duport
- SQPOV, UMR0408, Avignon Université, INRA, F-84914 Avignon, France
- Correspondence:
| | - Béatrice Alpha-Bazin
- Laboratoire Innovations technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207 Bagnols sur Cèze, France; (B.A.-B.); (J.A.)
| | - Jean Armengaud
- Laboratoire Innovations technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207 Bagnols sur Cèze, France; (B.A.-B.); (J.A.)
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328
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Krainer G, Keller S, Schlierf M. Structural dynamics of membrane-protein folding from single-molecule FRET. Curr Opin Struct Biol 2019; 58:124-137. [DOI: 10.1016/j.sbi.2019.05.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/27/2019] [Indexed: 12/15/2022]
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329
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Griffin S, Healey GD, Sheldon IM. Isoprenoids increase bovine endometrial stromal cell tolerance to the cholesterol-dependent cytolysin from Trueperella pyogenes. Biol Reprod 2019; 99:749-760. [PMID: 29688258 PMCID: PMC6203874 DOI: 10.1093/biolre/ioy099] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/23/2018] [Indexed: 12/11/2022] Open
Abstract
Preventing postpartum uterine disease depends on the ability of endometrial cells to tolerate the presence of the bacteria that invade the uterus after parturition. Postpartum uterine disease and endometrial pathology in cattle are most associated with the pathogen Trueperella pyogenes. Trueperella pyogenes secretes a cholesterol-dependent cytolysin, pyolysin, which causes cytolysis by forming pores in the plasma membrane of endometrial stromal cells. The aim of the present study was to identify cell-intrinsic pathways that increase bovine endometrial stromal cell tolerance to pyolysin. Pyolysin caused dose-dependent cytolysis of bovine endometrial stromal cells and leakage of lactate dehydrogenase into supernatants. Cell tolerance to pyolysin was increased by inhibitors that target the mevalonate and cholesterol synthesis pathway, but not the mitogen-activated protein kinase, cell cycle, or metabolic pathways. Cellular cholesterol was reduced and cell tolerance to pyolysin was increased by supplying the mevalonate-derived isoprenoid farnesyl pyrophosphate, or by inhibiting farnesyl-diphosphate farnesyltransferase 1 or geranylgeranyl diphosphate synthase 1 to increase the abundance of farnesyl pyrophosphate. Supplying the mevalonate-derived isoprenoid geranylgeranyl pyrophosphate also increased cell tolerance to pyolysin, but independent of changes in cellular cholesterol. However, geranylgeranyl pyrophosphate inhibits nuclear receptor subfamily 1 group H receptors (NR1H, also known as liver X receptors), and reducing the expression of the genes encoding NR1H3 or NR1H2 increased stromal cell tolerance to pyolysin. In conclusion, mevalonate-derived isoprenoids increased bovine endometrial stromal cell tolerance to pyolysin, which was associated with reducing cellular cholesterol and inhibiting NR1H receptors.
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Affiliation(s)
- Sholeem Griffin
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Gareth D Healey
- Swansea University Medical School, Swansea University, Swansea, UK
| | - I Martin Sheldon
- Swansea University Medical School, Swansea University, Swansea, UK
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330
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Mesa-Galloso H, Valiente PA, Valdés-Tresanco ME, Epand RF, Lanio ME, Epand RM, Alvarez C, Tieleman DP, Ros U. Membrane Remodeling by the Lytic Fragment of SticholysinII: Implications for the Toroidal Pore Model. Biophys J 2019; 117:1563-1576. [PMID: 31587828 DOI: 10.1016/j.bpj.2019.09.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/07/2019] [Accepted: 09/09/2019] [Indexed: 01/15/2023] Open
Abstract
Sticholysins are pore-forming toxins of biomedical interest and represent a prototype of proteins acting through the formation of protein-lipid or toroidal pores. Peptides spanning the N-terminus of sticholysins can mimic their permeabilizing activity and, together with the full-length toxins, have been used as a tool to understand the mechanism of pore formation in membranes. However, the lytic mechanism of these peptides and the lipid shape modulating their activity are not completely clear. In this article, we combine molecular dynamics simulations and experimental biophysical tools to dissect different aspects of the pore-forming mechanism of StII1-30, a peptide derived from the N-terminus of sticholysin II (StII). With this combined approach, membrane curvature induction and flip-flop movement of the lipids were identified as two important membrane remodeling steps mediated by StII1-30. Pore formation by this peptide was enhanced by the presence of the negatively curved lipid phosphatidylethanolamine in membranes. This lipid emerged not only as a facilitator of membrane interactions but also as a structural element of the StII1-30 pore that is recruited to the ring upon its assembly. Collectively, these, to our knowledge, new findings support a toroidal model for the architecture of the pore formed by StII1-30 and provide new molecular insight into the role of phosphatidylethanolamine as a membrane component that can easily integrate into the ring of toroidal pores, thus probably aiding in their stabilization. This study contributes to a better understanding of the molecular mechanism underlying the permeabilizing activity of StII1-30 and peptides or proteins acting via a toroidal pore mechanism and offers an informative framework for the optimization of the biomedical application of this and similar molecules.
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Affiliation(s)
- Haydee Mesa-Galloso
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta, Canada; Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Pedro A Valiente
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Mario E Valdés-Tresanco
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta, Canada; Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Raquel F Epand
- Department of Biochemistry and Biomedical Sciences, Health Science Center, McMaster University, Hamilton, Ontario, Canada
| | - Maria E Lanio
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, Health Science Center, McMaster University, Hamilton, Ontario, Canada
| | - Carlos Alvarez
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - D Peter Tieleman
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta, Canada.
| | - Uris Ros
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba; Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany.
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331
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Omersa N, Podobnik M, Anderluh G. Inhibition of Pore-Forming Proteins. Toxins (Basel) 2019; 11:E545. [PMID: 31546810 PMCID: PMC6784129 DOI: 10.3390/toxins11090545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
Perforation of cellular membranes by pore-forming proteins can affect cell physiology, tissue integrity, or immune response. Since many pore-forming proteins are toxins or highly potent virulence factors, they represent an attractive target for the development of molecules that neutralize their actions with high efficacy. There has been an assortment of inhibitors developed to specifically obstruct the activity of pore-forming proteins, in addition to vaccination and antibiotics that serve as a plausible treatment for the majority of diseases caused by bacterial infections. Here we review a wide range of potential inhibitors that can specifically and effectively block the activity of pore-forming proteins, from small molecules to more specific macromolecular systems, such as synthetic nanoparticles, antibodies, antibody mimetics, polyvalent inhibitors, and dominant negative mutants. We discuss their mechanism of inhibition, as well as advantages and disadvantages.
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Affiliation(s)
- Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
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332
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Exploring the Nature of Cationic Blocker Recognition by the Anthrax Toxin Channel. Biophys J 2019; 117:1751-1763. [PMID: 31587826 DOI: 10.1016/j.bpj.2019.08.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/11/2019] [Accepted: 08/05/2019] [Indexed: 01/20/2023] Open
Abstract
Obstructing conductive pathways of the channel-forming toxins with targeted blockers is a promising drug design approach. Nearly all tested positively charged ligands have been shown to reversibly block the cation-selective channel-forming protective antigen (PA63) component of the binary anthrax toxin. The cationic ligands with more hydrophobic surfaces, particularly those carrying aromatic moieties, inhibited PA63 more effectively. To understand the physical basis of PA63 selectivity for a particular ligand, detailed information is required on how the blocker structural elements (e.g., positively charged and aromatic groups) influence the molecular kinetics of the blocker/channel binding reactions. In this study, we address this problem using the high-resolution single-channel planar lipid bilayer technique. Several structurally distinct cationic blockers, namely per-6-S-(3-amino) propyl-β-cyclodextrin, per-6-S-(3-aminomethyl) benzyl-α-cyclodextrin, per-6-S-(3-aminomethyl) benzyl-β-cyclodextrin, per-6-S-(3-aminomethyl) benzyl-γ-cyclodextrin, methyltriphenylphosphonium ion, and G0 polyamidoamine dendrimer are tested for their ability to inhibit the heptameric and octameric PA63 variants and PA63F427A mutant. The F427 residues form a hydrophobic constriction region inside the channel, known as the "ϕ-clamp." We show that the cationic blockers interact with PA63 through a combination of forces. Analysis of the binding reaction kinetics suggests the involvement of cation-π, Coulomb, and salt-concentration-independent π-π or hydrophobic interactions in the cationic cyclodextrin binding. It is possible that these blockers bind to the ϕ-clamp and are also stabilized by the Coulomb interactions of their terminal amino groups with the water-exposed negatively charged channel residues. In PA63F427A, only the suggested Coulomb component of the cyclodextrin interaction remains. Methyltriphenylphosphonium ion and G0 polyamidoamine dendrimer, despite being positively charged, interact primarily with the ϕ-clamp. We also show that seven- and eightfold symmetric cyclodextrins effectively block the heptameric and octameric forms of PA63 interchangeably, adding flexibility to the earlier formulated blocker/target symmetry match requirement.
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333
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Yap WY, Tan KJSX, Hwang JS. Expansion of Hydra actinoporin-like toxin (HALT) gene family: Expression divergence and functional convergence evolved through gene duplication. Toxicon 2019; 170:10-20. [PMID: 31513812 DOI: 10.1016/j.toxicon.2019.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 11/15/2022]
Abstract
Hydra actinoporin-like toxin 1 (HALT-1) was previously shown to cause cytolysis and haemolysis in a number of human cells and has similar functional properties to the actinoporins equinatoxin and sticholysin. In addition to HALT-1, five other HALTs (HALTs 2, 3, 4, 6 and 7) were also isolated from Hydra magnipapillata and expressed as recombinant proteins in this study. We demonstrated that recombinant HALTs have cytolytic activity on HeLa cells but each exhibited a different range of toxicity. All six recombinant HALTs bound to sulfatide, while rHALT-1 and rHALT-3 bound to two additional sphingolipids, lysophosphatidic acid and sphingosine-1-phosphate as indicated by the protein-lipid overlay assay. When either tryptophan133 or tyrosine129 of HALT-1 was mutated, the mutant protein lost binding to sulfatide, lysophosphatidic acid and sphingosine-1-phosphate. As further verification of HALTs' binding to sulfatide, we performed ELISA for each HALT. To determine the cell-type specific gene expression of seven HALTs in Hydra, we searched for individual HALT expression in the single-cell RNA-seq data set of Single Cell Portal. The results showed that HALT-1, 4 and 7 were expressed in differentiating stenoteles. HALT-1 and HALT-6 were expressed in the female germline during oogenesis. HALT-2 was strongly expressed in the gland and mucous cells in the endoderm. Information on HALT-3 and HALT-5 could not be found in the single-cell data set. Our findings show that subfunctionalisation of gene expression following duplication enabled HALTs to become specialized in various cell types of the interstitial cell lineage.
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Affiliation(s)
- Wei Yuen Yap
- Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights Cheras, 56000, Kuala Lumpur, Malaysia
| | - Katrina Joan Shu Xian Tan
- Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights Cheras, 56000, Kuala Lumpur, Malaysia
| | - Jung Shan Hwang
- Department of Medical Sciences, School of Healthcare and Medical Sciences, Sunway University, No. 5 Jalan Universiti, Bandar Sunway, 47500, Selangor Darul Ehsan, Malaysia.
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334
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Schumann MR, Brandt U, Adis C, Hartung L, Fleißner A. Plasma Membrane Integrity During Cell-Cell Fusion and in Response to Pore-Forming Drugs Is Promoted by the Penta-EF-Hand Protein PEF1 in Neurospora crassa. Genetics 2019; 213:195-211. [PMID: 31270133 PMCID: PMC6727798 DOI: 10.1534/genetics.119.302363] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/14/2019] [Indexed: 12/20/2022] Open
Abstract
Plasma membrane damage commonly occurs during cellular growth and development. To counteract these potentially lethal injuries, membrane repair mechanisms have evolved, which promote the integrity of the lipid bilayer. Although the membrane of fungi is the target of important clinical drugs and agricultural fungicides, the molecular mechanisms which mediate membrane repair in these organisms remain elusive. Here we identify the penta-EF-hand protein PEF1 of the genetic model fungus Neurospora crassa as part of a cellular response mechanism against different types of membrane injury. Deletion of the pef1 gene in the wild type and different lysis-prone gene knockout mutants revealed a function of the protein in maintaining cell integrity during cell-cell fusion and in the presence of pore-forming drugs, such as the plant defense compound tomatine. By fluorescence and live-cell imaging we show that green fluorescent protein (GFP)-tagged PEF1 accumulates at the sites of membrane injury in a Ca2+-dependent manner. Site-directed mutagenesis identified Ca2+-binding domains essential for the spatial dynamics and function of the protein. In addition, the subcellular localization of PEF1 revealed that the syncytial fungal colony undergoes compartmentation in response to antifungal treatment. We propose that plasma membrane repair in fungi constitutes an additional line of defense against membrane-disturbing drugs, thereby expanding the current model of fungal drug resistance mechanisms.
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Affiliation(s)
| | - Ulrike Brandt
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
| | - Christian Adis
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
| | - Lisa Hartung
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
| | - André Fleißner
- Institut für Genetik, Technische Universität Braunschweig, 38106, Germany
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335
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Mutter NL, Volarić J, Szymanski W, Feringa BL, Maglia G. Reversible Photocontrolled Nanopore Assembly. J Am Chem Soc 2019; 141:14356-14363. [PMID: 31469268 PMCID: PMC6743218 DOI: 10.1021/jacs.9b06998] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
Self-assembly
is a fundamental feature of biological systems, and
control of such processes offers fascinating opportunities to regulate
function. Fragaceatoxin C (FraC) is a toxin that upon binding to the
surface of sphingomyelin-rich cells undergoes a structural metamorphosis,
leading to the assembly of nanopores at the cell membrane and causing
cell death. In this study we attached photoswitchable azobenzene pendants
to various locations near the sphingomyelin binding pocket of FraC
with the aim of remote controlling the nanopore assembly using light.
We found several constructs in which the affinity of the toxin for
biological membranes could be activated or deactivated by irradiation,
thus enabling reversible photocontrol of pore formation. Notably,
one construct was completely inactive in the thermally adapted state;
it however induced full lysis of cultured cancer cells upon light
irradiation. Selective irradiation also allowed isolation of individual
nanopores in artificial lipid membranes. Photocontrolled FraC might
find applications in photopharmacology for cancer therapeutics and
has potential to be used for the fabrication of nanopore arrays in
nanopore sensing devices, where the reconstitution, with high spatiotemporal
precision, of single nanopores must be controlled.
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Affiliation(s)
| | | | - Wiktor Szymanski
- University Medical Center Groningen, Department of Radiology , University of Groningen , Hanzeplein 1 , 9713 GZ , Groningen , The Netherlands
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336
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Gómez-Bañuelos E, Mukherjee A, Darrah E, Andrade F. Rheumatoid Arthritis-Associated Mechanisms of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. J Clin Med 2019; 8:jcm8091309. [PMID: 31454946 PMCID: PMC6780899 DOI: 10.3390/jcm8091309] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 12/19/2022] Open
Abstract
Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology characterized by immune-mediated damage of synovial joints and antibodies to citrullinated antigens. Periodontal disease, a bacterial-induced inflammatory disease of the periodontium, is commonly observed in RA and has implicated periodontal pathogens as potential triggers of the disease. In particular, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans have gained interest as microbial candidates involved in RA pathogenesis by inducing the production of citrullinated antigens. Here, we will discuss the clinical and mechanistic evidence surrounding the role of these periodontal bacteria in RA pathogenesis, which highlights a key area for the treatment and preventive interventions in RA.
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Affiliation(s)
- Eduardo Gómez-Bañuelos
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Amarshi Mukherjee
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Erika Darrah
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
| | - Felipe Andrade
- Division of Rheumatology, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
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337
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Humisto A, Jokela J, Teigen K, Wahlsten M, Permi P, Sivonen K, Herfindal L. Characterization of the interaction of the antifungal and cytotoxic cyclic glycolipopeptide hassallidin with sterol-containing lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1510-1521. [DOI: 10.1016/j.bbamem.2019.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 02/15/2019] [Accepted: 03/15/2019] [Indexed: 01/30/2023]
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338
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Nagahama M, Takehara M, Rood JI. Histotoxic Clostridial Infections. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0024-2018. [PMID: 31350831 PMCID: PMC10957196 DOI: 10.1128/microbiolspec.gpp3-0024-2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Indexed: 01/01/2023] Open
Abstract
The pathogenesis of clostridial myonecrosis or gas gangrene involves an interruption to the blood supply to the infected tissues, often via a traumatic wound, anaerobic growth of the infecting clostridial cells, the production of extracellular toxins, and toxin-mediated cell and tissue damage. This review focuses on host-pathogen interactions in Clostridium perfringens-mediated and Clostridium septicum-mediated myonecrosis. The major toxins involved are C. perfringens α-toxin, which has phospholipase C and sphingomyelinase activity, and C. septicum α-toxin, a β-pore-forming toxin that belongs to the aerolysin family. Although these toxins are cytotoxic, their effects on host cells are quite complex, with a range of intracellular cell signaling pathways induced by their action on host cell membranes.
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Affiliation(s)
- Masahiro Nagahama
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Masaya Takehara
- Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
| | - Julian I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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339
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Sannigrahi A, Nandi I, Chall S, Jawed JJ, Halder A, Majumdar S, Karmakar S, Chattopadhyay K. Conformational Switch Driven Membrane Pore Formation by Mycobacterium Secretory Protein MPT63 Induces Macrophage Cell Death. ACS Chem Biol 2019; 14:1601-1610. [PMID: 31241303 DOI: 10.1021/acschembio.9b00327] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Virulent Mycobacterium tuberculosis (MTB) strains cause cell death of macrophages (Mϕ) inside TB granuloma using a mechanism which is not well understood. Many bacterial systems utilize toxins to induce host cell damage, which occurs along with immune evasion. These toxins often use chameleon sequences to generate an environment-sensitive conformational switch, facilitating the process of infection. The presence of toxins is not yet known for MTB. Here, we show that MTB-secreted immunogenic MPT63 protein undergoes a switch from β-sheet to helix in response to mutational and environmental stresses. MPT63 in its helical form creates pores in both synthetic and Mϕ membranes, while the native β-sheet protein remains inert toward membrane interactions. Using fluorescence correlation spectroscopy and atomic force microscopy, we show further that the helical form undergoes self-association to produce toxic oligomers of different morphology. Trypan blue and flow cytometry analyses reveal that the helical state can be utilized by MTB for killing Mϕ cells. Collectively, our study emphasizes for the first time a toxin-like behavior of MPT63 induced by an environment-dependent conformational switch, resulting in membrane pore formation by toxic oligomers and Mϕ cell death.
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Affiliation(s)
- Achinta Sannigrahi
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Indrani Nandi
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sayantani Chall
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
| | | | - Animesh Halder
- Department of Physics, Jadavpur University, 188, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Subrata Majumdar
- Department of Molecular Medicine, Bose Institute, Kolkata 700054, India
| | - Sanat Karmakar
- Department of Physics, Jadavpur University, 188, Raja S. C. Mallick Road, Kolkata 700032, India
| | - Krishnananda Chattopadhyay
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S. C. Mallick Road, Kolkata 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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340
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Brito C, Mesquita FS, Bleck CKE, Sellers JR, Cabanes D, Sousa S. Perfringolysin O-Induced Plasma Membrane Pores Trigger Actomyosin Remodeling and Endoplasmic Reticulum Redistribution. Toxins (Basel) 2019; 11:toxins11070419. [PMID: 31319618 PMCID: PMC6669444 DOI: 10.3390/toxins11070419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/10/2019] [Accepted: 07/15/2019] [Indexed: 01/28/2023] Open
Abstract
Clostridium perfringens produces an arsenal of toxins that act together to cause severe infections in humans and livestock animals. Perfringolysin O (PFO) is a cholesterol-dependent pore-forming toxin encoded in the chromosome of virtually all C. perfringens strains and acts in synergy with other toxins to determine the outcome of the infection. However, its individual contribution to the disease is poorly understood. Here, we intoxicated human epithelial and endothelial cells with purified PFO to evaluate the host cytoskeletal responses to PFO-induced damage. We found that, at sub-lytic concentrations, PFO induces a profound reorganization of the actomyosin cytoskeleton culminating into the assembly of well-defined cortical actomyosin structures at sites of plasma membrane (PM) remodeling. The assembly of such structures occurs concomitantly with the loss of the PM integrity and requires pore-formation, calcium influx, and myosin II activity. The recovery from the PM damage occurs simultaneously with the disassembly of cortical structures. PFO also targets the endoplasmic reticulum (ER) by inducing its disruption and vacuolation. ER-enriched vacuoles were detected at the cell cortex within the PFO-induced actomyosin structures. These cellular events suggest the targeting of the endothelium integrity at early stages of C. perfringens infection, in which secreted PFO is at sub-lytic concentrations.
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Affiliation(s)
- Cláudia Brito
- i3S-Instituto de Investigação e Inovação em Saúde, IBMC, Universidade do Porto, 4099-002 Porto, Portugal
- Programa Doutoral em Biologia Molecular e Celular (MCbiology), Instituto de Ciências Biomédicas Abel, Salazar, Universidade do Porto, 4099-002 Porto, Portugal
| | - Francisco S Mesquita
- i3S-Instituto de Investigação e Inovação em Saúde, IBMC, Universidade do Porto, 4099-002 Porto, Portugal
| | - Christopher K E Bleck
- Electron Microscopy Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Didier Cabanes
- i3S-Instituto de Investigação e Inovação em Saúde, IBMC, Universidade do Porto, 4099-002 Porto, Portugal
| | - Sandra Sousa
- i3S-Instituto de Investigação e Inovação em Saúde, IBMC, Universidade do Porto, 4099-002 Porto, Portugal.
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341
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Phobalysin: Fisheye View of Membrane Perforation, Repair, Chemotaxis and Adhesion. Toxins (Basel) 2019; 11:toxins11070412. [PMID: 31315179 PMCID: PMC6669599 DOI: 10.3390/toxins11070412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/04/2019] [Accepted: 07/11/2019] [Indexed: 11/30/2022] Open
Abstract
Phobalysin P (PhlyP, for photobacterial lysin encoded on a plasmid) is a recently described small β-pore forming toxin of Photobacterium damselae subsp. damselae (Pdd). This organism, belonging to the family of Vibrionaceae, is an emerging pathogen of fish and various marine animals, which occasionally causes life-threatening soft tissue infections and septicemia in humans. By using genetically modified Pdd strains, PhlyP was found to be an important virulence factor. More recently, in vitro studies with purified PhlyP elucidated some basic consequences of pore formation. Being the first bacterial small β-pore forming toxin shown to trigger calcium-influx dependent membrane repair, PhlyP has advanced to a revealing model toxin to study this important cellular function. Further, results from co-culture experiments employing various Pdd strains and epithelial cells together with data on other bacterial toxins indicate that limited membrane damage may generally enhance the association of bacteria with target cells. Thereby, remodeling of plasma membrane and cytoskeleton during membrane repair could be involved. In addition, a chemotaxis-dependent attack-and track mechanism influenced by environmental factors like salinity may contribute to PhlyP-dependent association of Pdd with cells. Obviously, a synoptic approach is required to capture the regulatory links governing the interaction of Pdd with target cells. The characterization of Pdd’s secretome may hold additional clues because it may lead to the identification of proteases activating PhlyP’s pro-form. Current findings on PhlyP support the notion that pore forming toxins are not just killer proteins but serve bacteria to fulfill more subtle functions, like accessing their host.
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342
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Hernández-Elizárraga VH, Olguín-López N, Hernández-Matehuala R, Ocharán-Mercado A, Cruz-Hernández A, Guevara-González RG, Caballero-Pérez J, Ibarra-Alvarado C, Sánchez-Rodríguez J, Rojas-Molina A. Comparative Analysis of the Soluble Proteome and the Cytolytic Activity of Unbleached and Bleached Millepora complanata ("Fire Coral") from the Mexican Caribbean. Mar Drugs 2019; 17:E393. [PMID: 31277227 PMCID: PMC6669453 DOI: 10.3390/md17070393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/25/2019] [Accepted: 06/28/2019] [Indexed: 01/24/2023] Open
Abstract
Coral bleaching caused by global warming has resulted in massive damage to coral reefs worldwide. Studies addressing the consequences of elevated temperature have focused on organisms of the class Anthozoa, and up to now, there is little information regarding the mechanisms by which reef forming Hydrozoans face thermal stress. In this study, we carried out a comparative analysis of the soluble proteome and the cytolytic activity of unbleached and bleached Millepora complanata ("fire coral") that inhabited reef colonies exposed to the 2015-2016 El Niño-Southern Oscillation in the Mexican Caribbean. A differential proteomic response involving proteins implicated in key cellular processes, such as glycolysis, DNA repair, stress response, calcium homeostasis, exocytosis, and cytoskeleton organization was found in bleached hydrocorals. Four of the proteins, whose levels increased in bleached specimens, displayed sequence similarity to a phospholipase A2, an astacin-like metalloprotease, and two pore forming toxins. However, a protein, which displayed sequence similarity to a calcium-independent phospholipase A2, showed lower levels in bleached cnidarians. Accordingly, the hemolytic effect of the soluble proteome of bleached hydrocorals was significantly higher, whereas the phospholipase A2 activity was significantly reduced. Our results suggest that bleached M. complanata is capable of increasing its toxins production in order to balance the lack of nutrients supplied by its symbionts.
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Affiliation(s)
- Víctor Hugo Hernández-Elizárraga
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Norma Olguín-López
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Rosalina Hernández-Matehuala
- Posgrado en Ciencias Químico Biológicas, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Andrea Ocharán-Mercado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Andrés Cruz-Hernández
- Laboratorio de Biología Molecular. Escuela de Agronomía, Universidad de La Salle Bajío, Av. Universidad 15 602, Colonia Lomas del Campestre, C.P. 37150 León, Guanajuato, México
| | - Ramón Gerardo Guevara-González
- C.A Ingeniería de Biosistemas, Facultad de Ingeniería-Campus Amazcala, Universidad Autónoma de Querétaro, Carr. Chichimequillas-Amazcala Km. 1, S/N, C.P. 76265 Amazcala, El Marqués, Querétaro, México
| | - Juan Caballero-Pérez
- Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - César Ibarra-Alvarado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México
| | - Judith Sánchez-Rodríguez
- Unidad Académica de Sistemas Arrecifales Puerto Morelos, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Prolongación Niños Héroes S/N, Puerto Morelos, C.P. 77580 Quintana Roo, México
| | - Alejandra Rojas-Molina
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, C.P. 76010 Querétaro, Querétaro, México.
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343
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Wilson JS, Churchill-Angus AM, Davies SP, Sedelnikova SE, Tzokov SB, Rafferty JB, Bullough PA, Bisson C, Baker PJ. Identification and structural analysis of the tripartite α-pore forming toxin of Aeromonas hydrophila. Nat Commun 2019; 10:2900. [PMID: 31263098 PMCID: PMC6602965 DOI: 10.1038/s41467-019-10777-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 05/29/2019] [Indexed: 02/07/2023] Open
Abstract
The alpha helical CytolysinA family of pore forming toxins (α-PFT) contains single, two, and three component members. Structures of the single component Eschericia coli ClyA and the two component Yersinia enterolytica YaxAB show both undergo conformational changes from soluble to pore forms, and oligomerization to produce the active pore. Here we identify tripartite α-PFTs in pathogenic Gram negative bacteria, including Aeromonas hydrophila (AhlABC). We show that the AhlABC toxin requires all three components for maximal cell lysis. We present structures of pore components which describe a bi-fold hinge mechanism for soluble to pore transition in AhlB and a contrasting tetrameric assembly employed by soluble AhlC to hide their hydrophobic membrane associated residues. We propose a model of pore assembly where the AhlC tetramer dissociates, binds a single membrane leaflet, recruits AhlB promoting soluble to pore transition, prior to AhlA binding to form the active hydrophilic lined pore. Pore forming toxins (PFTs) form the major group of virulence factors in many pathogenic bacteria. Here the authors identify tripartite α-helical PFTs in pathogenic Gram negative bacteria and structurally characterize AhlABC from Aeromonas hydrophila and propose a model for its pore assembly.
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Affiliation(s)
- Jason S Wilson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK
| | - Alicia M Churchill-Angus
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK
| | - Simon P Davies
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK.,School of Biomedical Sciences, Faculty of Biological Sciences and Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Svetlana E Sedelnikova
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK
| | - Svetomir B Tzokov
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK
| | - John B Rafferty
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK
| | - Per A Bullough
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK
| | - Claudine Bisson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK.,ISMB, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London, WC1E 7HX, UK
| | - Patrick J Baker
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire, S10 2TN, UK.
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344
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Ebeling J, Knispel H, Fünfhaus A, Genersch E. The biological role of the enigmatic C3larvinAB toxin of the honey bee pathogenic bacterium Paenibacillus larvae. Environ Microbiol 2019; 21:3091-3106. [PMID: 31187922 DOI: 10.1111/1462-2920.14709] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/03/2019] [Accepted: 06/09/2019] [Indexed: 11/30/2022]
Abstract
Paenibacillus larvae is the causative agent of the notifiable epizootic American foulbrood, a fatal bacterial disease of honey bee larvae. The species P. larvae has been classified into four differentially virulent and prevalent genotypes (ERIC I-IV), which also differ in their virulence factor equipment. Recently, a novel P. larvae toxin, the C3-like C3larvin, has been described. Genome analysis now revealed that the C3larvin gene is actually a part of a toxin locus encompassing two genes encoding a binary AB toxin with the A subunit being C3larvin (C3larvinA) and a putative B subunit (C3larvinB) encoded by the second gene. Sequence and structural analyses demonstrated that C3larvinB is a homologue of the Bacillus anthracis protective antigen (PA), the B subunit of anthrax toxin. The C3larvinAB toxin locus was interrupted by point mutations in all analysed P. larvae ERIC I and ERIC II strains. Only one P. larvae ERIC III/IV strain harboured an uninterrupted toxin locus comprising full-length genes for C3larvinA and B. Exposure bioassays did not substantiate a role as virulence factor for C3larvinAB in P. larvae ERIC I/II. However, the PA homologue C3larvinB had an influence on the virulence of the unique P. larvae strain expressing the functional C3larvinAB locus.
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Affiliation(s)
- Julia Ebeling
- Department of Molecular Microbiology and Bee Diseases, Institute for Bee Research, 16540, Hohen Neuendorf, Germany
| | - Henriette Knispel
- Department of Molecular Microbiology and Bee Diseases, Institute for Bee Research, 16540, Hohen Neuendorf, Germany
| | - Anne Fünfhaus
- Department of Molecular Microbiology and Bee Diseases, Institute for Bee Research, 16540, Hohen Neuendorf, Germany
| | - Elke Genersch
- Department of Molecular Microbiology and Bee Diseases, Institute for Bee Research, 16540, Hohen Neuendorf, Germany.,Freie Universität Berlin, Fachbereich Veterinärmedizin, Institut für Mikrobiologie und Tierseuchen, 14163, Berlin, Germany
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345
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Convergent recruitment of adamalysin-like metalloproteases in the venom of the red bark centipede (Scolopocryptops sexspinosus). Toxicon 2019; 168:1-15. [PMID: 31229627 DOI: 10.1016/j.toxicon.2019.06.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/10/2019] [Accepted: 06/14/2019] [Indexed: 12/17/2022]
Abstract
Many venom proteins have presumably been convergently recruited by taxa from diverse venomous lineages. These toxic proteins have characteristics that allow them to remain stable in solution and have a high propensity for toxic effects on prey and/or potential predators. Despite this well-established convergent toxin recruitment, some toxins seem to be lineage specific. To further investigate the toxic proteins found throughout venomous lineages, venom proteomics and venom-gland transcriptomics were performed on two individual red bark centipedes (Scolopocryptops sexspinosus). Combining the protein phenotype with the transcript genotype resulted in the first in-depth venom characterization of S. sexspinosus, including 72 venom components that were identified in both the transcriptome and proteome and 1468 nontoxin transcripts identified in the transcriptome. Ten different toxin families were represented in the venom and venom gland with the majority of the toxins belonging to metalloproteases, CAPS (cysteine-rich secretory protein, antigen 5, and pathogenesis-related 1 proteins), and β-pore-forming toxins. Nine of these toxin families shared a similar proteomic structure to venom proteins previously identified from other centipedes. However, the most highly expressed toxin family, the adamalysin-like metalloproteases, has until now only been observed in the venom of snakes. We confirmed adamalysin-like metalloprotease activity by means of in vivo functional assays. The recruitment of an adamalysin-like metalloprotease into centipede venom represents a striking case of convergent evolution.
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346
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Astley R, Miller FC, Mursalin MH, Coburn PS, Callegan MC. An Eye on Staphylococcus aureus Toxins: Roles in Ocular Damage and Inflammation. Toxins (Basel) 2019; 11:E356. [PMID: 31248125 PMCID: PMC6628431 DOI: 10.3390/toxins11060356] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen of the eye, capable of infecting external tissues such as the tear duct, conjunctiva, and the cornea, as well the inner and more delicate anterior and posterior chambers. S. aureus produces numerous toxins and enzymes capable of causing profound damage to tissues and organs, as well as modulating the immune response to these infections. Unfortunately, in the context of ocular infections, this can mean blindness for the patient. The role of α-toxin in corneal infection (keratitis) and infection of the interior of the eye (endophthalmitis) has been well established by comparing virulence in animal models and α-toxin-deficient isogenic mutants with their wild-type parental strains. The importance of other toxins, such as β-toxin, γ-toxin, and Panton-Valentine leukocidin (PVL), have been analyzed to a lesser degree and their roles in eye infections are less clear. Other toxins such as the phenol-soluble modulins have yet to be examined in any animal models for their contributions to virulence in eye infections. This review discusses the state of current knowledge of the roles of S. aureus toxins in eye infections and the controversies existing as a result of the use of different infection models. The strengths and limitations of these ocular infection models are discussed, as well as the need for physiological relevance in the study of staphylococcal toxins in these models.
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Affiliation(s)
- Roger Astley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Frederick C Miller
- Department of Cell Biology and Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Md Huzzatul Mursalin
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Phillip S Coburn
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Michelle C Callegan
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd., DMEI PA-418, Oklahoma City, OK 73104, USA.
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347
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Ostolaza H, González-Bullón D, Uribe KB, Martín C, Amuategi J, Fernandez-Martínez X. Membrane Permeabilization by Pore-Forming RTX Toxins: What Kind of Lesions Do These Toxins Form? Toxins (Basel) 2019; 11:toxins11060354. [PMID: 31216745 PMCID: PMC6628442 DOI: 10.3390/toxins11060354] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/12/2019] [Accepted: 06/16/2019] [Indexed: 12/22/2022] Open
Abstract
Pore-forming toxins (PFTs) form nanoscale pores across target membranes causing cell death. The pore-forming cytolysins of the RTX (repeats in toxin) family belong to a steadily increasing family of proteins characterized by having in their primary sequences a number of glycine- and aspartate-rich nonapeptide repeats. They are secreted by a variety of Gram-negative bacteria and form ion-permeable pores in several cell types, such as immune cells, epithelial cells, or erythrocytes. Pore-formation by RTX-toxins leads to the dissipation of ionic gradients and membrane potential across the cytoplasmic membrane of target cells, which results in cell death. The pores formed in lipid bilayers by the RTX-toxins share some common properties such as cation selectivity and voltage-dependence. Hemolytic and cytolytic RTX-toxins are important virulence factors in the pathogenesis of the producing bacteria. And hence, understanding the function of these proteins at the molecular level is critical to elucidating their role in disease processes. In this review we summarize the current state of knowledge on pore-formation by RTX toxins, and include recent results from our own laboratory regarding the pore-forming activity of adenylate cyclase toxin (ACT or CyaA), a large protein toxin secreted by Bordetella pertussis, the bacterium causative of whooping cough.
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Affiliation(s)
- Helena Ostolaza
- Departamento de Bioquímica y Biología Molecular (UPV/EHU) and Instituto Biofisika (UPV/EHU, CSIC), Aptdo. 644, 48080 Bilbao, Spain.
| | - David González-Bullón
- Departamento de Bioquímica y Biología Molecular (UPV/EHU) and Instituto Biofisika (UPV/EHU, CSIC), Aptdo. 644, 48080 Bilbao, Spain.
| | - Kepa B Uribe
- Departamento de Bioquímica y Biología Molecular (UPV/EHU) and Instituto Biofisika (UPV/EHU, CSIC), Aptdo. 644, 48080 Bilbao, Spain.
| | - Cesar Martín
- Departamento de Bioquímica y Biología Molecular (UPV/EHU) and Instituto Biofisika (UPV/EHU, CSIC), Aptdo. 644, 48080 Bilbao, Spain.
| | - Jone Amuategi
- Departamento de Bioquímica y Biología Molecular (UPV/EHU) and Instituto Biofisika (UPV/EHU, CSIC), Aptdo. 644, 48080 Bilbao, Spain.
| | - Xabier Fernandez-Martínez
- Departamento de Bioquímica y Biología Molecular (UPV/EHU) and Instituto Biofisika (UPV/EHU, CSIC), Aptdo. 644, 48080 Bilbao, Spain.
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348
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Morton CJ, Sani MA, Parker MW, Separovic F. Cholesterol-Dependent Cytolysins: Membrane and Protein Structural Requirements for Pore Formation. Chem Rev 2019; 119:7721-7736. [DOI: 10.1021/acs.chemrev.9b00090] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Craig J. Morton
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Michael W. Parker
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, Victoria 3010, Australia
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
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349
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Zeng F, Liu F, Yuan L, Zhou S, Shen J, Li N, Ren H, Zeng H. A Pore-Forming Tripeptide as an Extraordinarily Active Anion Channel. Org Lett 2019; 21:4826-4830. [DOI: 10.1021/acs.orglett.9b01723] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Fei Zeng
- College of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, Hunan, China 425100
| | - Fang Liu
- College of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, Hunan, China 425100
| | - Lin Yuan
- College of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, Hunan, China 425100
| | - Shaoyuan Zhou
- College of Chemical Engineering, Sichuan University, Chengdu, China 610065
| | - Jie Shen
- NanoBio Lab, 31 Biopolis Way, The Nanos, Singapore 138669
| | - Ning Li
- NanoBio Lab, 31 Biopolis Way, The Nanos, Singapore 138669
| | - Haisheng Ren
- College of Chemical Engineering, Sichuan University, Chengdu, China 610065
| | - Huaqiang Zeng
- NanoBio Lab, 31 Biopolis Way, The Nanos, Singapore 138669
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350
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Correlated protein conformational states and membrane dynamics during attack by pore-forming toxins. Proc Natl Acad Sci U S A 2019; 116:12839-12844. [PMID: 31189600 DOI: 10.1073/pnas.1821897116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Pore-forming toxins (PFTs) are a class of proteins implicated in a wide range of virulent bacterial infections and diseases. These toxins bind to target membranes and subsequently oligomerize to form functional pores that eventually lead to cell lysis. While the protein undergoes large conformational changes on the bilayer, the connection between intermediate oligomeric states and lipid reorganization during pore formation is largely unexplored. Cholesterol-dependent cytolysins (CDCs) are a subclass of PFTs widely implicated in food poisoning and other related infections. Using a prototypical CDC, listeriolysin O (LLO), we provide a microscopic connection between pore formation, lipid dynamics, and leakage kinetics by using a combination of Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS) measurements on single giant unilamellar vesicles (GUVs). Upon exposure to LLO, two distinct populations of GUVs with widely different leakage kinetics emerge. We attribute these differences to the existence of oligomeric intermediates, sampling various membrane-bound conformational states of the protein, and their intimate coupling to lipid rearrangement and dynamics. Molecular dynamics simulations capture the influence of various membrane-bound conformational states on the lipid and cholesterol dynamics, providing molecular interpretations to the FRET and FCS experiments. Our study establishes a microscopic connection between membrane binding and conformational changes and their influence on lipid reorganization during PFT-mediated cell lysis. Additionally, our study provides insights into membrane-mediated protein interactions widely implicated in cell signaling, fusion, folding, and other biomolecular processes.
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