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Shahi I, Dongas SA, Ilmain JK, Torres VJ, Ratner AJ. Characterization of tigurilysin, a novel human CD59-specific cholesterol-dependent cytolysin, reveals a role for host specificity in augmenting toxin activity. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001393. [PMID: 37702594 PMCID: PMC10569062 DOI: 10.1099/mic.0.001393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 09/05/2023] [Indexed: 09/14/2023]
Abstract
Cholesterol-dependent cytolysins (CDCs) are a large family of pore-forming toxins, produced by numerous Gram-positive pathogens. CDCs depend on host membrane cholesterol for pore formation; some CDCs also require surface-associated human CD59 (hCD59) for binding, conferring specificity for human cells. We purified a recombinant version of a putative CDC encoded in the genome of Streptococcus oralis subsp. tigurinus, tigurilysin (TGY), and used CRISPR/Cas9 to construct hCD59 knockout (KO) HeLa and JEG-3 cell lines. Cell viability assays with TGY on wild-type and hCD59 KO cells showed that TGY is a hCD59-dependent CDC. Two variants of TGY exist among S. oralis subsp. tigurinus genomes, only one of which is functional. We discovered that a single amino acid change between these two TGY variants determines its activity. Flow cytometry and oligomerization Western blots revealed that the single amino acid difference between the two TGY isoforms disrupts host cell binding and oligomerization. Furthermore, experiments with hCD59 KO cells and cholesterol-depleted cells demonstrated that TGY is fully dependent on both hCD59 and cholesterol for activity, unlike other known hCD59-dependent CDCs. Using full-length CDCs and toxin constructs differing only in the binding domain, we determined that having hCD59 dependence leads to increased lysis efficiency, conferring a potential advantage to organisms producing hCD59-dependent CDCs.
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Affiliation(s)
- Ifrah Shahi
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Sophia A. Dongas
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
| | - Juliana K. Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Adam J. Ratner
- Department of Pediatrics, New York University Grossman School of Medicine, New York, NY, USA
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
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2
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Shahi I, Dongas SA, Ilmain JK, Torres VJ, Ratner AJ. Characterization of Tigurilysin, a Novel Human CD59-Specific Cholesterol-Dependent Cytolysin, Reveals a Role for Host Specificity in Augmenting Toxin Activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.21.545930. [PMID: 37546867 PMCID: PMC10401958 DOI: 10.1101/2023.06.21.545930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Cholesterol dependent cytolysins (CDCs) are a large family of pore forming toxins, produced by numerous gram-positive pathogens. CDCs depend on host membrane cholesterol for pore formation; some CDCs also require surface associated human CD59 (hCD59) for binding, conferring specificity for human cells. We purified a recombinant version of a putative CDC encoded in the genome of Streptococcus oralis subsp. tigurinus , tigurilysin (TGY), and used CRISPR/Cas9 to construct hCD59 knockout (KO) HeLa and JEG-3 cell lines. Cell viability assays with TGY on WT and hCD59 KO cells showed that TGY is a hCD59-dependent CDC. Two variants of TGY exist among S. oralis subsp. tigurinus genomes, only one of which is functional. We discovered that a single amino acid change between these two TGY variants determines its activity. Flow cytometry and oligomerization western blots revealed that the single amino acid difference between the two TGY isoforms disrupts host cell binding and oligomerization. Furthermore, experiments with hCD59 KO cells and cholesterol depleted cells demonstrated that TGY is fully dependent on both hCD59 and cholesterol for activity, unlike other known hCD59-dependent CDCs. Using full-length CDCs and toxin constructs differing only in the binding domain, we determined that having hCD59-dependence leads to increased lysis efficiency, conferring a potential advantage to organisms producing hCD59-dependent CDCs. IMPORTANCE Cholesterol dependent cytolysins (CDCs) are produced by a variety of disease-causing bacteria, and may play a significant role in pathogenesis. Understanding CDC mechanisms of action provides useful information for developing anti-virulence strategies against bacteria that utilize CDCs and other pore-forming toxins in pathogenesis. This study describes for the first time a novel human-specific CDC with an atypical pore forming mechanism compared to known CDCs. In addition, this study demonstrates that human-specificity potentially confers increased lytic efficiency to CDCs. These data provide a possible explanation for the selective advantage of developing hCD59-dependency in CDCs and the consequent host restriction.
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Affiliation(s)
- Ifrah Shahi
- New York University Grossman School of Medicine, Department of Pediatrics, New York, NY
| | - Sophia A. Dongas
- New York University Grossman School of Medicine, Department of Pediatrics, New York, NY
| | - Juliana K. Ilmain
- New York University Grossman School of Medicine, Department of Microbiology, New York, NY
| | - Victor J. Torres
- New York University Grossman School of Medicine, Department of Microbiology, New York, NY
| | - Adam J. Ratner
- New York University Grossman School of Medicine, Department of Pediatrics, New York, NY
- New York University Grossman School of Medicine, Department of Microbiology, New York, NY
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3
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Voisin TB, Couves EC, Tate EW, Bubeck D. Dynamics and Molecular Interactions of GPI-Anchored CD59. Toxins (Basel) 2023; 15:430. [PMID: 37505699 PMCID: PMC10467114 DOI: 10.3390/toxins15070430] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/13/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023] Open
Abstract
CD59 is a GPI-anchored cell surface receptor that serves as a gatekeeper to controlling pore formation. It is the only membrane-bound inhibitor of the complement membrane attack complex (MAC), an immune pore that can damage human cells. While CD59 blocks MAC pores, the receptor is co-opted by bacterial pore-forming proteins to target human cells. Recent structures of CD59 in complexes with binding partners showed dramatic differences in the orientation of its ectodomain relative to the membrane. Here, we show how GPI-anchored CD59 can satisfy this diversity in binding modes. We present a PyLipID analysis of coarse-grain molecular dynamics simulations of a CD59-inhibited MAC to reveal residues of complement proteins (C6:Y285, C6:R407 C6:K412, C7:F224, C8β:F202, C8β:K326) that likely interact with lipids. Using modules of the MDAnalysis package to investigate atomistic simulations of GPI-anchored CD59, we discover properties of CD59 that encode the flexibility necessary to bind both complement proteins and bacterial virulence factors.
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Affiliation(s)
- Tomas B. Voisin
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - Emma C. Couves
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - Edward W. Tate
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London W12 0BZ, UK
| | - Doryen Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
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4
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Tomoyasu T, Matsumoto A, Takao A, Tabata A, Nagamune H. A simple method to differentiate three classes of cholesterol-dependent cytolysins. J Microbiol Methods 2023; 207:106696. [PMID: 36898586 DOI: 10.1016/j.mimet.2023.106696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023]
Abstract
Cholesterol-dependent cytolysins (CDCs) are proteinaceous toxins widely distributed in gram-positive pathogenic bacteria. CDCs can be classified into three groups (I-III) based on the mode of receptor recognition. Group I CDCs recognize cholesterol as their receptor. Group II CDC specifically recognizes human CD59 as the primary receptor on the cell membrane. Only intermedilysin from Streptococcus intermedius has been reported as a group II CDC. Group III CDCs recognize both human CD59 and cholesterol as receptors. CD59 contains five disulfide bridges in its tertiary structure. Therefore, we treated human erythrocytes with dithiothreitol (DTT) to inactivate CD59 on membranes. Our data showed that DTT treatment caused a complete loss of recognition of intermedilysin and an anti-human CD59 monoclonal antibody. In contrast, this treatment did not affect the recognition of group I CDCs, judging from the fact that DTT-treated erythrocytes were lysed with the same efficiency as mock-treated human erythrocytes. The recognition of group III CDCs toward DTT-treated erythrocytes was partially reduced, and these results are likely due to the loss of human CD59 recognition. Therefore, the degree of human CD59 and cholesterol requirements of uncharacterized group III CDCs frequently found in Mitis group streptococci can be easily estimated by comparing the amounts of hemolysis between DTT-treated and mock-treated erythrocytes.
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Affiliation(s)
- Toshifumi Tomoyasu
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Airi Matsumoto
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Ayuko Takao
- Department of Oral Microbiology, School of Dental Medicine, Tsurumi University, Yokohama, Kanagawa, Japan
| | - Atsushi Tabata
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan
| | - Hideaki Nagamune
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan; Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, Tokushima, Japan.
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5
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Johnstone BA, Joseph R, Christie MP, Morton CJ, McGuiness C, Walsh JC, Böcking T, Tweten RK, Parker MW. Cholesterol-dependent cytolysins: The outstanding questions. IUBMB Life 2022; 74:1169-1179. [PMID: 35836358 PMCID: PMC9712165 DOI: 10.1002/iub.2661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 06/23/2022] [Indexed: 11/06/2022]
Abstract
The cholesterol-dependent cytolysins (CDCs) are a major family of bacterial pore-forming proteins secreted as virulence factors by Gram-positive bacterial species. CDCs are produced as soluble, monomeric proteins that bind specifically to cholesterol-rich membranes, where they oligomerize into ring-shaped pores of more than 30 monomers. Understanding the details of the steps the toxin undergoes in converting from monomer to a membrane-spanning pore is a continuing challenge. In this review we summarize what we know about CDCs and highlight the remaining outstanding questions that require answers to obtain a complete picture of how these toxins kill cells.
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Affiliation(s)
- Bronte A Johnstone
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Riya Joseph
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Michelle P Christie
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Craig J Morton
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Conall McGuiness
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - James C Walsh
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Till Böcking
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Michael W Parker
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- Australian Cancer Research Foundation Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
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Mondal AK, Chattopadhyay K. Structures and functions of the membrane-damaging pore-forming proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:241-288. [PMID: 35034720 DOI: 10.1016/bs.apcsb.2021.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pore-forming proteins (PFPs) of the diverse life forms have emerged as the potent cell-killing entities owing to their specialized membrane-damaging properties. PFPs have the unique ability to perforate the plasma membranes of their target cells, and they exert this functionality by creating oligomeric pores in the membrane lipid bilayer. Pathogenic bacteria employ PFPs as toxins to execute their virulence mechanisms, whereas in the higher vertebrates PFPs are deployed as the part of the immune system and to generate inflammatory responses. PFPs are the unique dimorphic proteins that are generally synthesized as water-soluble molecules, and transform into membrane-inserted oligomeric pore assemblies upon interacting with the target membranes. In spite of sharing very little sequence similarity, PFPs from diverse organisms display incredible structural similarity. Yet, at the same time, structure-function mechanisms of the PFPs document remarkable versatility. Such notions establish PFPs as the fascinating model system to explore variety of unsolved issues pertaining to the structure-function paradigm of the proteins that interact and act in the membrane environment. In this article, we discuss our current understanding regarding the structural basis of the pore-forming functions of the diverse class of PFPs. We attempt to highlight the similarities and differences in their structures, membrane pore-formation mechanisms, and their implications for the various biological processes, ranging from the bacterial virulence mechanisms to the inflammatory immune response generation in the higher animals.
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Affiliation(s)
- Anish Kumar Mondal
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Kausik Chattopadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India.
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7
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Molecular Dynamics Study of Lipid and Cholesterol Reorganization Due to Membrane Binding and Pore Formation by Listeriolysin O. J Membr Biol 2020; 253:535-550. [DOI: 10.1007/s00232-020-00148-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 10/10/2020] [Indexed: 12/20/2022]
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8
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Thanawastien A, Joyce KE, Cartee RT, Haines LA, Pelton SI, Tweten RK, Killeen KP. Preclinical in vitro and in vivo profile of a highly-attenuated, broadly efficacious pneumolysin genetic toxoid. Vaccine 2020; 39:1652-1660. [PMID: 32532546 PMCID: PMC8237519 DOI: 10.1016/j.vaccine.2020.04.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 04/03/2020] [Accepted: 04/26/2020] [Indexed: 02/05/2023]
Abstract
Pneumolysin is a highly conserved, cholesterol-dependent cytolysin that is an important Streptococcus pneumoniae virulence factor and an attractive target for vaccine development. To attenuate pneumolysin toxicity, a genetic toxoid was constructed with two amino acid changes, G293S and L460D, termed PLY-D, that reduced cytolytic activity > 125,000-fold. In mice, PLY-D elicited high anti-PLY IgG antibody titers that neutralized the cytolytic activity of the wild-type toxin in vitro. To evaluate the protective efficacy of PLY-D, mice were immunized intramuscularly and then challenged intranasally with a lethal dose of 28 clinical isolates of S. pneumoniae originating from different geographical locations, disease states (i.e. bacteremia, pneumonia), or body sites (i.e. sputum, blood). PLY-D immunization conferred significant protection from challenge with 17 of 20 serotypes (85%) and 22 of 28 strains (79%). Further, we demonstrated that immunization with PLY-D provided statistically significant improvement in survival against challenge with serotype 4 and 18C strains compared to mice immunized with a pneumococcal conjugate vaccine Prevnar 13® (PCV13). Co-administration of PLY-D and PCV13 conferred greater protection against challenge with a serotype 6B strain than immunization with either vaccine alone. These data indicate that PLY-D is a broadly protective antigen with the potential to serve as a serotype-independent vaccine against invasive pneumococcal disease either alone or in combination with PCVs.
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Affiliation(s)
- Ann Thanawastien
- Matrivax Research & Development Corporation, Boston, MA, United States
| | - Kelsey E Joyce
- Matrivax Research & Development Corporation, Boston, MA, United States
| | - Robert T Cartee
- Matrivax Research & Development Corporation, Boston, MA, United States
| | - Laurel A Haines
- Matrivax Research & Development Corporation, Boston, MA, United States
| | - Stephen I Pelton
- Boston University Schools of Medicine and Public Health, Boston Medical Center, Boston, MA, United States
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, United States
| | - Kevin P Killeen
- Matrivax Research & Development Corporation, Boston, MA, United States.
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Bruggisser J, Tarek B, Wyder M, Müller P, von Ballmoos C, Witz G, Enzmann G, Deutsch U, Engelhardt B, Posthaus H. CD31 (PECAM-1) Serves as the Endothelial Cell-Specific Receptor of Clostridium perfringens β-Toxin. Cell Host Microbe 2020; 28:69-78.e6. [PMID: 32497498 DOI: 10.1016/j.chom.2020.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/31/2020] [Accepted: 05/05/2020] [Indexed: 01/25/2023]
Abstract
Clostridium perfringens β-toxin (CPB) is a highly active β-pore-forming toxin (β-PFT) and the essential virulence factor for fatal, necro-hemorrhagic enteritis in animals and humans. The molecular mechanisms involved in CPB's action on its target, the endothelium of small intestinal vessels, are poorly understood. Here, we identify platelet endothelial cell adhesion molecule-1 (CD31 or PECAM-1) as the specific membrane receptor for CPB on endothelial cells. CD31 expression corresponds with the cell-type specificity of CPB, and it is essential for toxicity in cultured cells and mice. Ectopic CD31 expression renders resistant cells and liposomes susceptible to CPB-induced membrane damage. Moreover, the extracellular Ig6 domain of mouse, human, and porcine CD31 is essential for the interaction with CPB. Hence, our results explain the cell-type specificity of CPB in vitro and in the natural disease caused by C. perfringens type C.
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Affiliation(s)
- Julia Bruggisser
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland
| | - Basma Tarek
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland
| | - Marianne Wyder
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland
| | - Philipp Müller
- Department of Chemistry and Biochemistry, Faculty of Sciences, University of Bern, 3012 Bern, Switzerland
| | - Christoph von Ballmoos
- Department of Chemistry and Biochemistry, Faculty of Sciences, University of Bern, 3012 Bern, Switzerland
| | - Guillaume Witz
- Microscopy Imaging Center (MIC) University of Bern, 3012 Bern, Switzerland; Science IT Support (ScITS), Mathematical Institute, University of Bern, Bern, Switzerland
| | - Gaby Enzmann
- Theodor Kocher Institute, Faculty of Medicine, University of Bern, 3012 Bern, Switzerland
| | - Urban Deutsch
- Theodor Kocher Institute, Faculty of Medicine, University of Bern, 3012 Bern, Switzerland
| | - Britta Engelhardt
- Theodor Kocher Institute, Faculty of Medicine, University of Bern, 3012 Bern, Switzerland
| | - Horst Posthaus
- Institute of Animal Pathology, Department of Infectious Diseases and Pathobiology, Vetsuisse-Faculty, University of Bern, 3012 Bern, Switzerland; COMPATH, Vetsuisse-Faculty & Faculty of Medicine, University of Bern, 3012 Bern, Switzerland.
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10
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Cheng C, Sun J, Yu H, Ma T, Guan C, Zeng H, Zhang X, Chen Z, Song H. Listeriolysin O Pore-Forming Activity Is Required for ERK1/2 Phosphorylation During Listeria monocytogenes Infection. Front Immunol 2020; 11:1146. [PMID: 32582211 PMCID: PMC7283531 DOI: 10.3389/fimmu.2020.01146] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/11/2020] [Indexed: 12/18/2022] Open
Abstract
Listeriolysin O (LLO) is a cholesterol-dependent cytolysin that mediates escape of L. monocytogenes from phagosomes and enables the bacteria to grow within the host. LLO is a versatile tool allowing Listeria to trigger several cellular responses. In this study, rapid phosphorylation of ERK1/2 on Caco-2 cells caused by Listeria infection was demonstrated to be highly dependent on LLO activity. The effect could be strongly induced by adding purified recombinant LLO alone and could be inhibited by exogenous cholesterol. Lack of the PEST sequence, known to tightly control cytotoxicity of LLO, did not affect ERK1/2 activation. However, the recombinant non-cytolytic LLOT515AL516A, with mutations in the cholesterol-binding motif, was unable to trigger this response. Recombinant LLON478AV479A, which lacks most of the cytolytic activity, also failed to activate ERK1/2 phosphorylation, and this effect could be rescued when the protein concentration reached a cytolytic level. Infection with an LLO-deficient mutant (Δhly) or the mutant complementing LLOT515AL516A abrogated the capacity of the bacteria to activate ERK1/2. However, infection with the Δhly mutant complementing LLON478AV479A, which retained partial pore-forming ability and could grow intracellularly, was capable of triggering ERK1/2 phosphorylation. Collectively, these data suggest that ERK1/2 activation by L. monocytogenes depends on the permeabilization activity of LLO and more importantly correlates with the cholesterol-binding motif of LLO.
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Affiliation(s)
- Changyong Cheng
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Jing Sun
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Huifei Yu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Tiantian Ma
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Chiyu Guan
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Huan Zeng
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Xian Zhang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Zhongwei Chen
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
| | - Houhui Song
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, China
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11
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An Intermolecular π-Stacking Interaction Drives Conformational Changes Necessary to β-Barrel Formation in a Pore-Forming Toxin. mBio 2019; 10:mBio.01017-19. [PMID: 31266869 PMCID: PMC6606804 DOI: 10.1128/mbio.01017-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
A unique feature of the CDC/MACPF/SNTX (cholesterol-dependent cytolysin/membrane attack complex perforin/stonefish toxin) superfamily of pore-forming toxins is that the β-strands that comprise the β-barrel pore are derived from a pair of α-helical bundles. These studies reveal the molecular basis by which the formation of intermolecular interactions within the prepore complex drive the disruption of intramolecular interactions within each monomer of the prepore to trigger the α-helical–to–β-strand transition and formation of the β-barrel pore. The crystal structures of the soluble monomers of the pore-forming cholesterol-dependent cytolysins (CDCs) contain two α-helical bundles that flank a twisted core β-sheet. This protein fold is the hallmark of the CDCs, as well as of the membrane attack complex/perforin immune defense proteins and the stonefish toxins. To form the β-barrel pore, a core β-sheet is flattened to align the membrane-spanning β-hairpins. Concomitantly with this conformational change, the two α-helical bundles that flank the core β-sheet break their restraining contacts and refold into two membrane-spanning β-hairpins of the β-barrel pore. The studies herein show that in the monomer structure of the archetype CDC perfringolysin O (PFO), a conserved Met-Met-Phe triad simultaneously contributes to maintaining the twist in this core β-sheet, as well as restricting the α-helical–to–β-strand transition necessary to form one of two membrane-spanning β-hairpins. A previously identified intermolecular π-stacking interaction is now shown to disrupt the interactions mediated by this conserved triad. This is required to establish the subsequent intermolecular electrostatic interaction, which has previously been shown to drive the final conformational changes necessary to form the β-barrel pore. Hence, these studies show that the intermolecular π-stacking and electrostatic interactions work in tandem to flatten the core β-sheet and initiate the α-helical–to–β-strand transitions to form the β-barrel pore.
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12
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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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13
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Kulma M, Kacprzyk-Stokowiec A, Traczyk G, Kwiatkowska K, Dadlez M. Fine-tuning of the stability of β-strands by Y181 in perfringolysin O directs the prepore to pore transition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:110-122. [PMID: 30463694 DOI: 10.1016/j.bbamem.2018.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 05/15/2018] [Accepted: 08/19/2018] [Indexed: 11/29/2022]
Abstract
Perfringolysin O (PFO) is a toxic protein that forms β-barrel transmembrane pores upon binding to cholesterol-containing membranes. The formation of lytic pores requires conformational changes in PFO that lead to the conversion of water-soluble monomers into membrane-bound oligomers. Although the general outline of stepwise pore formation has been established, the underlying mechanistic details await clarification. To extend our understanding of the molecular mechanisms that control the pore formation, we compared the hydrogen-deuterium exchange patterns of PFO with its derivatives bearing mutations in the D3 domain. In the case of two of these mutations F318A, Y181A, known from previous work to lead to a decreased lytic activity, global destabilization of all protein domains was observed in their water-soluble forms. This was accompanied by local changes in D3 β-sheet, including unexpected stabilization of functionally important β1 strand in Y181A. In case of the double mutation (F318A/Y181A) that completely abolished the lytic activity, several local changes were retained, but the global destabilization effects of single mutations were reverted and hydrogen-deuterium exchange (HDX) pattern returned to PFO level. Strong structural perturbations were not observed in case of remaining variants in which other residues of the hydrophobic core of D3 domain were substituted by alanine. Our results indicate the existence in PFO of a well-tuned H-bonding network that maintains the stability of the D3 β-strands at appropriate level at each transformation step. F318 and Y181 moieties participate in this network and their role extends beyond their direct intermolecular interaction during oligomerization that was identified previously.
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Affiliation(s)
- Magdalena Kulma
- Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawinskiego St., 02-106 Warsaw, Poland
| | - Aleksandra Kacprzyk-Stokowiec
- Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawinskiego St., 02-106 Warsaw, Poland
| | - Gabriela Traczyk
- Department of Cell Biology, The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Department of Cell Biology, The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Michał Dadlez
- Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 5A Pawinskiego St., 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Department of Biology, Warsaw University, 1 Miecznikowa St., 02-185 Warsaw, Poland.
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14
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Christie MP, Johnstone BA, Tweten RK, Parker MW, Morton CJ. Cholesterol-dependent cytolysins: from water-soluble state to membrane pore. Biophys Rev 2018; 10:1337-1348. [PMID: 30117093 DOI: 10.1007/s12551-018-0448-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/07/2018] [Indexed: 12/22/2022] Open
Abstract
The cholesterol-dependent cytolysins (CDCs) are a family of bacterial toxins that are important virulence factors for a number of pathogenic Gram-positive bacterial species. CDCs are secreted as soluble, stable monomeric proteins that bind specifically to cholesterol-rich cell membranes, where they assemble into well-defined ring-shaped complexes of around 40 monomers. The complex then undergoes a concerted structural change, driving a large pore through the membrane, potentially lysing the target cell. Understanding the details of this process as the protein transitions from a discrete monomer to a complex, membrane-spanning protein machine is an ongoing challenge. While many of the details have been revealed, there are still questions that remain unanswered. In this review, we present an overview of some of the key features of the structure and function of the CDCs, including the structure of the secreted monomers, the process of interaction with target membranes, and the transition from bound monomers to complete pores. Future directions in CDC research and the potential of CDCs as research tools will also be discussed.
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Affiliation(s)
- Michelle P Christie
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Bronte A Johnstone
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Michael W Parker
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
- Australian Cancer Research Foundation Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, VIC, 3065, Australia.
| | - Craig J Morton
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
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15
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van Pee K, Neuhaus A, D'Imprima E, Mills DJ, Kühlbrandt W, Yildiz Ö. CryoEM structures of membrane pore and prepore complex reveal cytolytic mechanism of Pneumolysin. eLife 2017; 6. [PMID: 28323617 PMCID: PMC5437283 DOI: 10.7554/elife.23644] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/17/2017] [Indexed: 12/20/2022] Open
Abstract
Many pathogenic bacteria produce pore-forming toxins to attack and kill human cells. We have determined the 4.5 Å structure of the ~2.2 MDa pore complex of pneumolysin, the main virulence factor of Streptococcus pneumoniae, by cryoEM. The pneumolysin pore is a 400 Å ring of 42 membrane-inserted monomers. Domain 3 of the soluble toxin refolds into two ~85 Å β-hairpins that traverse the lipid bilayer and assemble into a 168-strand β-barrel. The pore complex is stabilized by salt bridges between β-hairpins of adjacent subunits and an internal α-barrel. The apolar outer barrel surface with large sidechains is immersed in the lipid bilayer, while the inner barrel surface is highly charged. Comparison of the cryoEM pore complex to the prepore structure obtained by electron cryo-tomography and the x-ray structure of the soluble form reveals the detailed mechanisms by which the toxin monomers insert into the lipid bilayer to perforate the target membrane.
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Affiliation(s)
- Katharina van Pee
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Alexander Neuhaus
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Edoardo D'Imprima
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Deryck J Mills
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Özkan Yildiz
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
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16
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Kulma M, Kacprzyk-Stokowiec A, Kwiatkowska K, Traczyk G, Sobota A, Dadlez M. R468A mutation in perfringolysin O destabilizes toxin structure and induces membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1075-1088. [PMID: 28263714 DOI: 10.1016/j.bbamem.2017.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 02/20/2017] [Accepted: 03/01/2017] [Indexed: 11/30/2022]
Abstract
Perfringolysin O (PFO) belongs to the family of cholesterol-dependent cytolysins. Upon binding to a cholesterol-containing membrane, PFO undergoes a series of structural changes that result in the formation of a β-barrel pore and cell lysis. Recognition and binding to cholesterol are mediated by the D4 domain, one of four domains of PFO. The D4 domain contains a conserved tryptophan-rich loop named undecapeptide (E458CTGLAWEWWR468) in which arginine 468 is essential for retaining allosteric coupling between D4 and other domains during interaction of PFO with the membrane. In this report we studied the impact of R468A mutation on the whole protein structure using hydrogen-deuterium exchange coupled with mass spectrometry. We found that in aqueous solution, compared to wild type (PFO), PFOR468A showed increased deuterium uptake due to exposure of internal toxin regions to the solvent. This change reflected an overall structural destabilization of PFOR468A in solution. Conversely, upon binding to cholesterol-containing membranes, PFOR468A revealed a profound decrease of hydrogen-deuterium exchange when compared to PFO. This block of deuterium uptake resulted from PFOR468A-induced aggregation and fusion of liposomes, as found by dynamic light scattering, microscopic observations and FRET measurements. In the result of liposome aggregation and fusion, the entire PFOR468A molecule became shielded from aqueous solution and thereby was protected against proteolytic digestion and deuteration. We have established that structural changes induced by the R468A mutation lead to exposure of an additional cholesterol-independent liposome-binding site in PFO that confers its fusogenic property, altering the mode of the toxin action.
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Affiliation(s)
- Magdalena Kulma
- Department of Biophysics, Institute of Biochemistry and Biophysics of the Polish Academy of Sciences, 5A Pawinskiego St., 02-106 Warsaw, Poland
| | - Aleksandra Kacprzyk-Stokowiec
- Department of Biophysics, Institute of Biochemistry and Biophysics of the Polish Academy of Sciences, 5A Pawinskiego St., 02-106 Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Gabriela Traczyk
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Andrzej Sobota
- Laboratory of Molecular Membrane Biology, Department of Cell Biology, Nencki Institute of Experimental Biology of the Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
| | - Michał Dadlez
- Department of Biophysics, Institute of Biochemistry and Biophysics of the Polish Academy of Sciences, 5A Pawinskiego St., 02-106 Warsaw, Poland; Institute of Genetics and Biotechnology, Department of Biology, Warsaw University, 1 Miecznikowa St., 02-185 Warsaw, Poland.
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17
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van Pee K, Mulvihill E, Müller DJ, Yildiz Ö. Unraveling the Pore-Forming Steps of Pneumolysin from Streptococcus pneumoniae. NANO LETTERS 2016; 16:7915-7924. [PMID: 27796097 DOI: 10.1021/acs.nanolett.6b04219] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Pneumolysin (PLY) is the main virulence factor of Streptococcus pneumoniae that causes pneumonia, meningitis, and invasive pneumococcal infection. PLY is produced as monomers, which bind to cholesterol-containing membranes, where they oligomerize into large pores. To investigate the pore-forming mechanism, we determined the crystal structure of PLY at 2.4 Å and used it to design mutants on the surface of monomers. Electron microscopy of liposomes incubated with PLY mutants revealed that several mutations interfered with ring formation. Mutants that formed incomplete rings or linear arrays had strongly reduced hemolytic activity. By high-resolution time-lapse atomic force microscopy of wild-type PLY, we observed two different ring-shaped complexes. Most of the complexes protruded ∼8 nm above the membrane surface, while a smaller number protruded ∼11 nm or more. The lower complexes were identified as pores or prepores by the presence or absence of a lipid bilayer in their center. The taller complexes were side-by-side assemblies of monomers of soluble PLY that represent an early form of the prepore. Our observations suggest a four-step mechanism of membrane attachment and pore formation by PLY, which is discussed in the context of recent structural models. The functional separation of these steps is necessary for the understanding how cholesterol-dependent cytolysins form pores and lyse cells.
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Affiliation(s)
- Katharina van Pee
- Department of Structural Biology, Max PIanck Institute of Biophysics , Max von Laue Strasse 3, 60438 Frankfurt am Main, Germany
| | - Estefania Mulvihill
- Department of Biosystems Science and Engineering, ETH Zurich , Mattenstrasse 26, 4058 Basel, Switzerland
| | - Daniel J Müller
- Department of Biosystems Science and Engineering, ETH Zurich , Mattenstrasse 26, 4058 Basel, Switzerland
| | - Özkan Yildiz
- Department of Structural Biology, Max PIanck Institute of Biophysics , Max von Laue Strasse 3, 60438 Frankfurt am Main, Germany
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18
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Boyd CM, Parsons ES, Smith RAG, Seddon JM, Ces O, Bubeck D. Disentangling the roles of cholesterol and CD59 in intermedilysin pore formation. Sci Rep 2016; 6:38446. [PMID: 27910935 PMCID: PMC5133593 DOI: 10.1038/srep38446] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/08/2016] [Indexed: 01/08/2023] Open
Abstract
The plasma membrane provides an essential barrier, shielding a cell from the pressures of its external environment. Pore-forming proteins, deployed by both hosts and pathogens alike, breach this barrier to lyse target cells. Intermedilysin is a cholesterol-dependent cytolysin that requires the human immune receptor CD59, in addition to cholesterol, to form giant β-barrel pores in host membranes. Here we integrate biochemical assays with electron microscopy and atomic force microscopy to distinguish the roles of these two receptors in mediating structural transitions of pore formation. CD59 is required for the specific coordination of intermedilysin (ILY) monomers and for triggering collapse of an oligomeric prepore. Movement of Domain 2 with respect to Domain 3 of ILY is essential for forming a late prepore intermediate that releases CD59, while the role of cholesterol may be limited to insertion of the transmembrane segments. Together these data define a structural timeline for ILY pore formation and suggest a mechanism that is relevant to understanding other pore-forming toxins that also require CD59.
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Affiliation(s)
- Courtney M. Boyd
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
| | - Edward S. Parsons
- Department of Chemistry and Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Richard A. G. Smith
- MRC Centre for Transplantation, King’s College London, 5th Floor Tower Wing, Guys’ Hospital, London SE1 9RT, UK
| | - John M. Seddon
- Department of Chemistry and Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Oscar Ces
- Department of Chemistry and Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Doryen Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, Imperial College London, London SW7 2AZ, UK
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19
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Verherstraeten S, Goossens E, Valgaeren B, Pardon B, Timbermont L, Haesebrouck F, Ducatelle R, Deprez P, Van Immerseel F. Non-toxic perfringolysin O and α-toxin derivatives as potential vaccine candidates against bovine necrohaemorrhagic enteritis. Vet J 2016; 217:89-94. [PMID: 27810219 DOI: 10.1016/j.tvjl.2016.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 09/19/2016] [Accepted: 09/28/2016] [Indexed: 12/25/2022]
Abstract
Bovine necrohaemorrhagic enteritis is a fatal Clostridium perfringens type A-induced disease that is characterised by sudden death. Recently the involvement of perfringolysin O and α-toxin in the development of necrohaemorrhagic lesions in the gut of calves was suggested, and thus derivatives of these toxins are potentially suitable as vaccine antigens. In the current study, the perfringolysin O derivative PFOL491D, alone or in combination with α-toxin derivative GST-cpa247-370, was evaluated as possible vaccine candidate, using in vitro assays. PFOL491D showed no haemolytic effect on horse red blood cells and no cytotoxic effect on bovine endothelial cells. Furthermore, calves immunised with PFOL491D raised antibodies against perfringolysin O that could inhibit the perfringolysin O-associated haemolytic activity on horse red blood cells. Antisera from calves immunised with PFOL491D had a significantly higher neutralising capacity against the cytotoxic effect of C. perfringens culture supernatant to bovine endothelial cells than serum from control calves (P <0.05). Immunisation of calves with PFOL491D in combination with GST-cpa247-370 elicited antibodies against perfringolysin O and α-toxin and consequently inhibited both the perfringolysin O-associated haemolytic activity and the α-toxin-associated lecithinase activity in vitro. Additionally, the neutralising ability of these antisera on the cytotoxic effect of C. perfringens culture supernatant to bovine endothelial cells was significantly higher than that from calves immunised with PFOL491D (P <0.001). In conclusion, perfringolysin O derivative PFOL491D is an immunogenic antigen that can potentially be used to produce vaccine against bovine necrohaemorrhagic enteritis. Including α-toxin derivative GST-cpa247-370 has an additional protective effect and therefore vaccination of calves with a combination of both antigens seems even more promising.
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Affiliation(s)
- S Verherstraeten
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - E Goossens
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - B Valgaeren
- Department of Internal Medicine and Clinical Biology of Large Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - B Pardon
- Department of Internal Medicine and Clinical Biology of Large Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - L Timbermont
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - F Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - R Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - P Deprez
- Department of Internal Medicine and Clinical Biology of Large Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
| | - F Van Immerseel
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
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20
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Lawrence SL, Gorman MA, Feil SC, Mulhern TD, Kuiper MJ, Ratner AJ, Tweten RK, Morton CJ, Parker MW. Structural Basis for Receptor Recognition by the Human CD59-Responsive Cholesterol-Dependent Cytolysins. Structure 2016; 24:1488-98. [PMID: 27499440 PMCID: PMC5320943 DOI: 10.1016/j.str.2016.06.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 11/23/2022]
Abstract
Cholesterol-dependent cytolysins (CDCs) are a family of pore-forming toxins that punch holes in the outer membrane of eukaryotic cells. Cholesterol serves as the receptor, but a subclass of CDCs first binds to human CD59. Here we describe the crystal structures of vaginolysin and intermedilysin complexed to CD59. These studies, together with small-angle X-ray scattering, reveal that CD59 binds to each at different, though overlapping, sites, consistent with molecular dynamics simulations and binding studies. The CDC consensus undecapeptide motif, which for the CD59-responsive CDCs has a proline instead of a tryptophan in the motif, adopts a strikingly different conformation between the structures; our data suggest that the proline acts as a selectivity switch to ensure CD59-dependent CDCs bind their protein receptor first in preference to cholesterol. The structural data suggest a detailed model of how these water-soluble toxins assemble as prepores on the cell surface.
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Affiliation(s)
- Sara L Lawrence
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Michael A Gorman
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Susanne C Feil
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Terrence D Mulhern
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael J Kuiper
- Victorian Life Sciences Computation Initiative, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Adam J Ratner
- Departments of Pediatrics and Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Rodney K Tweten
- Department of Microbiology and Immunology, University of Oklahoma, Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Craig J Morton
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia
| | - Michael W Parker
- ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, Fitzroy, VIC 3065, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia.
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21
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Park SA, Park YS, Bong SM, Lee KS. Structure-based functional studies for the cellular recognition and cytolytic mechanism of pneumolysin from Streptococcus pneumoniae. J Struct Biol 2016; 193:132-40. [DOI: 10.1016/j.jsb.2015.12.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 12/01/2015] [Accepted: 12/09/2015] [Indexed: 01/01/2023]
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22
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Zhou J, Du X, Li J, Yamagata N, Xu B. Taurine Boosts Cellular Uptake of Small D-Peptides for Enzyme-Instructed Intracellular Molecular Self-Assembly. J Am Chem Soc 2015; 137:10040-3. [PMID: 26235707 PMCID: PMC4544318 DOI: 10.1021/jacs.5b06181] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Indexed: 02/08/2023]
Abstract
Due to their biostability, D-peptides are emerging as an important molecular platform for biomedical applications. Being proteolytically resistant, D-peptides lack interactions with endogenous transporters and hardly enter cells. Here we show that taurine, a natural amino acid, drastically boosts the cellular uptake of small D-peptides in mammalian cells by >10-fold, from 118 μM (without conjugating taurine) to >1.6 mM (after conjugating taurine). The uptake of a large amount of the ester conjugate of taurine and D-peptide allows intracellular esterase to trigger intracellular self-assembly of the D-peptide derivative, further enhancing their cellular accumulation. The study on the mechanism of the uptake reveals that the conjugates enter cells via both dynamin-dependent endocytosis and macropinocytosis, but likely not relying on taurine transporters. Differing fundamentally from the positively charged cell-penetrating peptides, the biocompatibility, stability, and simplicity of the enzyme-cleavable taurine motif promise new ways to promote the uptake of bioactive molecules for countering the action of efflux pump and contributing to intracellular molecular self-assembly.
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Affiliation(s)
- Jie Zhou
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States
| | - Xuewen Du
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States
| | - Jie Li
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States
| | - Natsuko Yamagata
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, United States
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23
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Farrand AJ, Hotze EM, Sato TK, Wade KR, Wimley WC, Johnson AE, Tweten RK. The Cholesterol-dependent Cytolysin Membrane-binding Interface Discriminates Lipid Environments of Cholesterol to Support β-Barrel Pore Insertion. J Biol Chem 2015; 290:17733-17744. [PMID: 26032415 DOI: 10.1074/jbc.m115.656769] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Indexed: 12/25/2022] Open
Abstract
The majority of cholesterol-dependent cytolysins (CDCs) utilize cholesterol as a membrane receptor, whereas a small number are restricted to the GPI-anchored protein CD59 for initial membrane recognition. Two cholesterol-binding CDCs, perfringolysin O (PFO) and streptolysin O (SLO), were found to exhibit strikingly different binding properties to cholesterol-rich natural and synthetic membranes. The structural basis for this difference was mapped to one of the loops (L3) in the membrane binding interface that help anchor the toxin monomers to the membrane after receptor (cholesterol) binding by the membrane insertion of its amino acid side chains. A single point mutation in this loop conferred the binding properties of SLO to PFO and vice versa. Our studies strongly suggest that changing the side chain structure of this loop alters its equilibrium between membrane-inserted and uninserted states, thereby affecting the overall binding affinity and total bound toxin. Previous studies have shown that the lipid environment of cholesterol has a dramatic effect on binding and activity. Combining this data with the results of our current studies on L3 suggests that the structure of this loop has evolved in the different CDCs to preferentially direct binding to cholesterol in different lipid environments. Finally, the efficiency of β-barrel pore formation was inversely correlated with the increased binding and affinity of the PFO L3 mutant, suggesting that selection of a compatible lipid environment impacts the efficiency of membrane insertion of the β-barrel pore.
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Affiliation(s)
- Allison J Farrand
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Eileen M Hotze
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Takehiro K Sato
- Departments of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas 77843
| | - Kristin R Wade
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - William C Wimley
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112
| | - Arthur E Johnson
- Departments of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas 77843; Departments of Chemistry and Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843
| | - Rodney K Tweten
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104.
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An intermolecular electrostatic interaction controls the prepore-to-pore transition in a cholesterol-dependent cytolysin. Proc Natl Acad Sci U S A 2015; 112:2204-9. [PMID: 25646411 DOI: 10.1073/pnas.1423754112] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
β-Barrel pore-forming toxins (βPFTs) form an obligatory oligomeric prepore intermediate before the formation of the β-barrel pore. The molecular components that control the critical prepore-to-pore transition remain unknown for βPFTs. Using the archetype βPFT perfringolysin O, we show that E183 of each monomer within the prepore complex forms an intermolecular electrostatic interaction with K336 of the adjacent monomer on completion of the prepore complex. The signal generated throughout the prepore complex by this interaction irrevocably commits it to the formation of the membrane-inserted giant β-barrel pore. This interaction supplies the free energy to overcome the energy barrier (determined here to be ∼ 19 kcal/mol) to the prepore-to-pore transition by the coordinated disruption of a critical interface within each monomer. These studies provide the first insight to our knowledge into the molecular mechanism that controls the prepore-to-pore transition for a βPFT.
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The cytolytic activity of vaginolysin strictly depends on cholesterol and is potentiated by human CD59. Toxins (Basel) 2015; 7:110-28. [PMID: 25590277 PMCID: PMC4303817 DOI: 10.3390/toxins7010110] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/07/2015] [Indexed: 12/29/2022] Open
Abstract
Gardnerella vaginalis produces cytolysin vaginolysin (VLY), which has been suggested to be a contributor to bacterial vaginosis pathogenesis. VLY along with intermedilysin (ILY) from Streptococcus intermedius have been attributed to a group of cholesterol-dependent cytolysins (CDCs) whose pore-forming activity depends on human CD59 (hCD59). Here, we show that different types of cells lacking hCD59 are susceptible to VLY-mediated lysis, albeit to different extents. We analyze the effects of both hCD59 and cholesterol on VLY cytolytic activity. We show that VLY binds to cholesterol-rich membranes of non-human cells, while VLY with an impaired cholesterol recognition site retains binding to the hCD59-containing cells. We further demonstrate that cholesterol binding by VLY is sufficient to trigger the formation of oligomeric complexes on cholesterol rich-liposomes lacking hCD59. Thus, VLY may induce cell lysis following two alternative pathways. One requires only cholesterol and does not depend on hCD59. The second pathway involves hCD59 contribution similarly to ILY. Apparently, under physiological conditions VLY acts in the most effective way by accepting the assistance of hCD59.
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Tweten RK, Hotze EM, Wade KR. The Unique Molecular Choreography of Giant Pore Formation by the Cholesterol-Dependent Cytolysins of Gram-Positive Bacteria. Annu Rev Microbiol 2015; 69:323-40. [PMID: 26488276 PMCID: PMC7875328 DOI: 10.1146/annurev-micro-091014-104233] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The mechanism by which the cholesterol-dependent cytolysins (CDCs) assemble their giant β-barrel pore in cholesterol-rich membranes has been the subject of intense study in the past two decades. A combination of structural, biophysical, and biochemical analyses has revealed deep insights into the series of complex and highly choreographed secondary and tertiary structural transitions that the CDCs undergo to assemble their β-barrel pore in eukaryotic membranes. Our knowledge of the molecular details of these dramatic structural changes in CDCs has transformed our understanding of how giant pore complexes are assembled and has been critical to our understanding of the mechanisms of other important classes of pore-forming toxins and proteins across the kingdoms of life. Finally, there are tantalizing hints that the CDC pore-forming mechanism is more sophisticated than previously imagined and that some CDCs are employed in pore-independent processes.
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Affiliation(s)
- Rodney K Tweten
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104;
| | - Eileen M Hotze
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104;
| | - Kristin R Wade
- Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104;
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Tabata A, Ohkura K, Ohkubo Y, Tomoyasu T, Ohkuni H, Whiley RA, Nagamune H. The diversity of receptor recognition in cholesterol-dependent cytolysins. Microbiol Immunol 2014; 58:155-71. [PMID: 24401114 DOI: 10.1111/1348-0421.12131] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/25/2013] [Accepted: 01/05/2014] [Indexed: 11/30/2022]
Abstract
Cholesterol-dependent cytolysins (CDCs) are bacterial pore-forming toxins secreted mainly by pathogenic Gram-positive bacteria. CDCs generally recognize and bind to membrane cholesterol to create pores and lyse target cells. However, in contrast to typical CDCs such as streptolysin O, several atypical CDCs have been reported. The first of these was intermedilysin, which is secreted by Streptococcus intermedius and has human cell-specificity, human CD59 (huCD59) being its receptor. In the study reported here, the diversity of receptor recognition among CDCs was investigated and multi-receptor recognition characteristics were identified within this toxin family. Streptococcus mitis-derived human platelet aggregation factor (Sm-hPAF) secreted by S. mitis strain Nm-65 isolated from a patient with Kawasaki disease was previously shown to hemolyze erythrocytes in a species-dependent manner, its maximum activity being in human cells. In the present study, it was found that Sm-hPAF recognizes both membrane cholesterol and huCD59 as receptors for triggering pore-formation. Moreover, vaginolysin (VLY) of Gardnerella vaginalis showed similar characteristics to Sm-hPAF regarding receptor recognition. On the basis of the results presented here, the mode of receptor recognition of CDCs can be categorized into the following three groups: (i) Group I, comprising typical CDCs with high affinity to cholesterol and no or very little affinity to huCD59; (ii) Group II, including atypical CDCs such as ILY, with no or very little affinity to cholesterol and high affinity to huCD59; and (iii) Group III, which contains atypical CDCs such as Sm-hPAF and VLY with affinity to both cholesterol and huCD59.
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Affiliation(s)
- Atsushi Tabata
- Department of Biological Science and Technology, Institute of Technology and Science, University of Tokushima Graduate School, 2-1 Minamijosanjima-cho, Tokushima, Tokushima, 770-8506
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Mozola CC, Magassa N, Caparon MG. A novel cholesterol-insensitive mode of membrane binding promotes cytolysin-mediated translocation by Streptolysin O. Mol Microbiol 2014; 94:675-87. [PMID: 25196983 DOI: 10.1111/mmi.12786] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2014] [Indexed: 11/30/2022]
Abstract
Cytolysin-mediated translocation (CMT), performed by Streptococcus pyogenes, utilizes the cholesterol-dependent cytolysin Streptolysin O (SLO) to translocate the NAD(+) -glycohydrolase (SPN) into the host cell during infection. SLO is required for CMT and can accomplish this activity without pore formation, but the details of SLO's interaction with the membrane preceding SPN translocation are unknown. Analysis of binding domain mutants of SLO and binding domain swaps between SLO and homologous cholesterol-dependent cytolysins revealed that membrane binding by SLO is necessary but not sufficient for CMT, demonstrating a specific requirement for SLO in this process. Despite being the only known receptor for SLO, this membrane interaction does not require cholesterol. Depletion of cholesterol from host membranes and mutation of SLO's cholesterol recognition motif abolished pore formation but did not inhibit membrane binding or CMT. Surprisingly, SLO requires the coexpression and membrane localization of SPN to achieve cholesterol-insensitive membrane binding; in the absence of SPN, SLO's binding is characteristically cholesterol-dependent. SPN's membrane localization also requires SLO, suggesting a co-dependent, cholesterol-insensitive mechanism of membrane binding occurs, resulting in SPN translocation.
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Affiliation(s)
- Cara C Mozola
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110-1093, USA
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Wade KR, Hotze EM, Briles DE, Tweten RK. Mouse, but not human, ApoB-100 lipoprotein cholesterol is a potent innate inhibitor of Streptococcus pneumoniae pneumolysin. PLoS Pathog 2014; 10:e1004353. [PMID: 25188225 PMCID: PMC4154877 DOI: 10.1371/journal.ppat.1004353] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/18/2014] [Indexed: 11/19/2022] Open
Abstract
Streptococcus pneumoniae produces the pore-forming toxin pneumolysin (PLY), which is a member of the cholesterol-dependent cytolysin (CDC) family of toxins. The CDCs recognize and bind the 3β-hydroxyl group of cholesterol at the cell surface, which initiates membrane pore formation. The cholesterol transport lipoproteins, which carry cholesterol in their outer monolayer, are potential off-pathway binding targets for the CDCs and are present at significant levels in the serum and the interstitial spaces of cells. Herein we show that cholesterol carried specifically by the ApoB-100-containing lipoprotein particles (CH-ApoB-100) in the mouse, but not that carried by human or guinea pig particles, is a potent inhibitor of the PLY pore-forming mechanism. Cholesterol present in the outer monolayer of mouse ApoB-100 particles is recognized and bound by PLY, which stimulates premature assembly of the PLY oligomeric complex thereby inactivating PLY. These studies further suggest that the vast difference in the inhibitory capacity of mouse CH-ApoB-100 and that of the human and the guinea pig is due to differences in the presentation of cholesterol in the outer monolayer of their ApoB-100 particles. Therefore mouse CH-ApoB-100 represents a significant innate CDC inhibitor that is absent in humans, which may underestimate the contribution of CDCs to human disease when utilizing mouse models of disease.
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Affiliation(s)
- Kristin R. Wade
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Eileen M. Hotze
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - David E. Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Rodney K. Tweten
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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Abstract
The complement terminal pathway clears pathogens by generating cytotoxic membrane attack complex (MAC) pores on target cells. For more than 40 years, biochemical and cellular assays have been used to characterize the lytic nature of the MAC and to define its protein composition. Although models for pore formation have been inferred from structures of bacterial cytolysins, it was only recently that we were able to visualize how complement components come together during MAC assembly. This review highlights structural analyses of terminal pathway complexes to explore molecular mechanisms underlying MAC formation.
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Affiliation(s)
- Doryen Bubeck
- Department of Life Sciences, Sir Ernst Chain Building, South Kensington Campus, Imperial College London , London SW7 2AZ, U.K
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31
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Seveau S. Multifaceted activity of listeriolysin O, the cholesterol-dependent cytolysin of Listeria monocytogenes. Subcell Biochem 2014; 80:161-95. [PMID: 24798012 DOI: 10.1007/978-94-017-8881-6_9] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The cholesterol-dependent cytolysins (CDCs) are a large family of pore-forming toxins that are produced by numerous Gram-positive bacterial pathogens. These toxins are released in the extracellular environment as water-soluble monomers or dimers that bind to cholesterol-rich membranes and assemble into large pore complexes. Depending upon their concentration, the nature of the host cell and membrane (cytoplasmic or intracellular) they target, the CDCs can elicit many different cellular responses. Among the CDCs, listeriolysin O (LLO), which is a major virulence factor of the facultative intracellular pathogen Listeria monocytogenes, is involved in several stages of the intracellular lifecycle of the bacterium and displays unique characteristics. It has long been known that following L. monocytogenes internalization into host cells, LLO disrupts the internalization vacuole, enabling the bacterium to replicate into the host cell cytosol. LLO is then used by cytosolic bacteria to spread from cell to cell, avoiding bacterial exposure to the extracellular environment. Although LLO is continuously produced during the intracellular lifecycle of L. monocytogenes, several processes limit its toxicity to ensure the survival of infected cells. It was previously thought that LLO activity was limited to mediating vacuolar escape during bacterial entry and cell to cell spreading. This concept has been challenged by compelling evidence suggesting that LLO secreted by extracellular L. monocytogenes perforates the host cell plasma membrane, triggering important host cell responses. This chapter provides an overview of the well-established intracellular activity of LLO and the multiple roles attributed to LLO secreted by extracellular L. monocytogenes.
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Affiliation(s)
- Stephanie Seveau
- Department of Microbiology, Department of Microbial Infection and Immunity, The Ohio State University, 484 West, 12th Avenue, Columbus, OH, 43210-1292, USA,
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Johnson BB, Heuck AP. Perfringolysin O structure and mechanism of pore formation as a paradigm for cholesterol-dependent cytolysins. Subcell Biochem 2014; 80:63-81. [PMID: 24798008 DOI: 10.1007/978-94-017-8881-6_5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cholesterol-dependent cytolysins (CDCs) constitute a family of pore forming toxins secreted by Gram-positive bacteria. These toxins form transmembrane pores by inserting a large β-barrel into cholesterol-containing membrane bilayers. Binding of water-soluble CDCs to the membrane triggers the formation of oligomers containing 35-50 monomers. The coordinated insertion of more than seventy β-hairpins into the membrane requires multiple structural conformational changes. Perfringolysin O (PFO), secreted by Clostridium perfringens, has become the prototype for the CDCs. In this chapter, we will describe current knowledge on the mechanism of PFO cytolysis, with special focus on cholesterol recognition, oligomerization, and the conformational changes involved in pore formation.
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Affiliation(s)
- Benjamin B Johnson
- Department of Biochemistry and Molecular Biology, University of Massachusetts, 710 N. Pleasant St., Lederle GRT, Amherst, MA, 01003, USA
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33
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Seitz M, Baums C, Neis C, Benga L, Fulde M, Rohde M, Goethe R, Valentin-Weigand P. Subcytolytic effects of suilysin on interaction of Streptococcus suis with epithelial cells. Vet Microbiol 2013; 167:584-91. [DOI: 10.1016/j.vetmic.2013.09.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 08/26/2013] [Accepted: 09/06/2013] [Indexed: 10/26/2022]
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The pore-forming haemolysins of bacillus cereus: a review. Toxins (Basel) 2013; 5:1119-39. [PMID: 23748204 PMCID: PMC3717773 DOI: 10.3390/toxins5061119] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/22/2013] [Accepted: 05/24/2013] [Indexed: 12/05/2022] Open
Abstract
The Bacillus cereus sensu lato group contains diverse Gram-positive spore-forming bacteria that can cause gastrointestinal diseases and severe eye infections in humans. They have also been incriminated in a multitude of other severe, and frequently fatal, clinical infections, such as osteomyelitis, septicaemia, pneumonia, liver abscess and meningitis, particularly in immuno-compromised patients and preterm neonates. The pathogenic properties of this organism are mediated by the synergistic effects of a number of virulence products that promote intestinal cell destruction and/or resistance to the host immune system. This review focuses on the pore-forming haemolysins produced by B. cereus: haemolysin I (cereolysin O), haemolysin II, haemolysin III and haemolysin IV (CytK). Haemolysin I belongs to the cholesterol-dependent cytolysin (CDC) family whose best known members are listeriolysin O and perfringolysin O, produced by L. monocytogenes and C. perfringens respectively. HlyII and CytK are oligomeric ß-barrel pore-forming toxins related to the α-toxin of S. aureus or the ß-toxin of C. perfringens. The structure of haemolysin III, the least characterized haemolytic toxin from the B. cereus, group has not yet been determined.
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Sato TK, Tweten RK, Johnson AE. Disulfide-bond scanning reveals assembly state and β-strand tilt angle of the PFO β-barrel. Nat Chem Biol 2013; 9:383-9. [PMID: 23563525 PMCID: PMC3661704 DOI: 10.1038/nchembio.1228] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 02/28/2013] [Indexed: 12/29/2022]
Abstract
Perfringolysin O (PFO), a bacterial cholesterol-dependent cytolysin, binds a mammalian cell membrane, oligomerizes into a circular prepore complex (PPC) and forms a 250-Å transmembrane β-barrel pore in the cell membrane. Each PFO monomer has two sets of three short α-helices that unfold and ultimately refold into two transmembrane β-hairpin (TMH) components of the membrane-embedded β-barrel. Interstrand disulfide-bond scanning revealed that β-strands in a fully assembled PFO β-barrel were strictly aligned and tilted at 20° to the membrane perpendicular. In contrast, in a low temperature-trapped PPC intermediate, the TMHs were unfolded and had sufficient freedom of motion to interact transiently with each other, yet the TMHs were not aligned or stably hydrogen bonded. The PFO PPC-to-pore transition therefore converts TMHs in a dynamic folding intermediate far above the membrane into TMHs that are hydrogen bonded to those of adjacent subunits in the bilayer-embedded β-barrel.
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Affiliation(s)
- Takehiro K. Sato
- Department of Molecular and Cellular Medicine, Texas A&M University System Health Science Center, College Station, TX 77843-1114
| | - Rodney K. Tweten
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73119
| | - Arthur E. Johnson
- Department of Molecular and Cellular Medicine, Texas A&M University System Health Science Center, College Station, TX 77843-1114
- Department of Chemistry, Texas A&M University, College Station, TX 77843
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
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Structural basis for recognition of the pore-forming toxin intermedilysin by human complement receptor CD59. Cell Rep 2013; 3:1369-77. [PMID: 23665225 PMCID: PMC3675674 DOI: 10.1016/j.celrep.2013.04.029] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/23/2013] [Accepted: 04/26/2013] [Indexed: 12/03/2022] Open
Abstract
Pore-forming proteins containing the structurally conserved membrane attack complex/perforin fold play an important role in immunity and host-pathogen interactions. Intermedilysin (ILY) is an archetypal member of a cholesterol-dependent cytolysin subclass that hijacks the complement receptor CD59 to make cytotoxic pores in human cells. ILY directly competes for the membrane attack complex binding site on CD59, rendering cells susceptible to complement lysis. To understand how these bacterial pores form in lipid bilayers and the role CD59 plays in complement regulation, we determined the crystal structure of human CD59 bound to ILY. Here, we show the ILY-CD59 complex at 3.5 Å resolution and identify two interfaces mediating this host-pathogen interaction. An ILY-derived peptide based on the binding site inhibits pore formation in a CD59-containing liposome model system. These data provide insight into how CD59 coordinates ILY monomers, nucleating an early prepore state, and suggest a potential mechanism of inhibition for the complement terminal pathway. Crystal structure of the ILY-CD59 complex defines two interfaces Our two binding interfaces are supported by previous mutagenesis studies An ILY-derived peptide competes for binding in a liposome model system Our model provides a structural basis for CD59 nucleation of an ILY early prepore
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Taylor SD, Sanders ME, Tullos NA, Stray SJ, Norcross EW, McDaniel LS, Marquart ME. The cholesterol-dependent cytolysin pneumolysin from Streptococcus pneumoniae binds to lipid raft microdomains in human corneal epithelial cells. PLoS One 2013; 8:e61300. [PMID: 23577214 PMCID: PMC3618221 DOI: 10.1371/journal.pone.0061300] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 03/11/2013] [Indexed: 11/22/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is an opportunistic bacterial pathogen responsible for causing several human diseases including pneumonia, meningitis, and otitis media. Pneumococcus is also a major cause of human ocular infections and is commonly isolated in cases of bacterial keratitis, an infection of the cornea. The ocular pathology that occurs during pneumococcal keratitis is partly due to the actions of pneumolysin (Ply), a cholesterol-dependent cytolysin produced by pneumococcus. The lytic mechanism of Ply is a three step process beginning with surface binding to cholesterol. Multiple Ply monomers then oligomerize to form a prepore. The prepore then undergoes a conformational change that creates a large pore in the host cell membrane, resulting in cell lysis. We engineered a collection of single amino acid substitution mutants at residues (A370, A406, W433, and L460) that are crucial to the progression of the lytic mechanism and determined the effects that these mutations had on lytic function. Both PlyWT and the mutant Ply molecules (PlyA370G, PlyA370E, PlyA406G, PlyA406E, PlyW433G, PlyW433E, PlyW433F, PlyL460G, and PlyL460E) were able to bind to the surface of human corneal epithelial cells (HCECs) with similar efficiency. Additionally, PlyWT localized to cholesterol-rich microdomains on the HCEC surface, however, only one mutant (PlyA370G) was able to duplicate this behavior. Four of the 9 mutant Ply molecules (PlyA370E, PlyW433G, PlyW433E, and PlyL460E) were deficient in oligomer formation. Lastly, all of the mutant Ply molecules, except PlyA370G, exhibited significantly impaired lytic activity on HCECs. The other 8 mutants all experienced a reduction in lytic activity, but 4 of the 8 retained the ability to oligomerize. A thorough understanding of the molecular interactions that occur between Ply and the target cell, could lead to targeted treatments aimed to reduce the pathology observed during pneumococcal keratitis.
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Affiliation(s)
- Sidney D. Taylor
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Melissa E. Sanders
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Nathan A. Tullos
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Stephen J. Stray
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Erin W. Norcross
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Larry S. McDaniel
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Mary E. Marquart
- Department of Microbiology, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
- * E-mail:
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Hu L, Joshi SB, Liyanage MR, Pansalawatta M, Alderson MR, Tate A, Robertson G, Maisonneuve J, Volkin DB, Middaugh CR. Physical characterization and formulation development of a recombinant pneumolysoid protein-based pneumococcal vaccine. J Pharm Sci 2012; 102:387-400. [PMID: 23161162 DOI: 10.1002/jps.23375] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/02/2012] [Accepted: 10/24/2012] [Indexed: 12/21/2022]
Abstract
Streptococcus pneumoniae is a major cause of death in children worldwide. There are more than 90 known pneumococcus serotypes that vary by geographical location. Pneumolysin is a protein toxin produced by virtually all invasive strains of S. pneumoniae and is considered an important virulence factor. Pneumolysin is immunogenic and has the potential to be a new vaccine antigen offering broad serotype-independent coverage. To develop a stable vaccine formulation, the conformational stability of a recombinant pneumolysin mutant (pneumolysoid L460D) was characterized by various techniques. Three data visualization diagrams were constructed to summarize the biophysical data of the L460D pneumolysoid; the protein is most stable in solution at pH 6-7, and loses conformational integrity above 48°C. Excipient screening assays were performed and sugars such as trehalose and sucrose stabilized the pneumolysin mutant with respect to improving thermal transition temperatures and minimizing aggregation. In addition, the protein antigen showed efficient binding to aluminum hydroxide adjuvant. The conformational stability of the L460D pneumolysoid on the surface of alhydrogel adjuvant was little affected by adsorption, either with or without excipients. These studies provide important preformulation characterization information useful for the development of a stable pneumolysin mutant-based vaccine.
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Affiliation(s)
- Lei Hu
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, USA
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The cholesterol-dependent cytolysin signature motif: a critical element in the allosteric pathway that couples membrane binding to pore assembly. PLoS Pathog 2012; 8:e1002787. [PMID: 22792065 PMCID: PMC3390400 DOI: 10.1371/journal.ppat.1002787] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Accepted: 05/19/2012] [Indexed: 12/03/2022] Open
Abstract
The cholesterol-dependent cytolysins (CDCs) constitute a family of pore-forming toxins that contribute to the pathogenesis of a large number of Gram-positive bacterial pathogens.The most highly conserved region in the primary structure of the CDCs is the signature undecapeptide sequence (ECTGLAWEWWR). The CDC pore forming mechanism is highly sensitive to changes in its structure, yet its contribution to the molecular mechanism of the CDCs has remained enigmatic. Using a combination of fluorescence spectroscopic methods we provide evidence that shows the undecapeptide motif of the archetype CDC, perfringolysin O (PFO), is a key structural element in the allosteric coupling of the cholesterol-mediated membrane binding in domain 4 (D4) to distal structural changes in domain 3 (D3) that are required for the formation of the oligomeric pore complex. Loss of the undecapeptide function prevents all measurable D3 structural transitions, the intermolecular interaction of membrane bound monomers and the assembly of the oligomeric pore complex. We further show that this pathway does not exist in intermedilysin (ILY), a CDC that exhibits a divergent undecapeptide and that has evolved to use human CD59 rather than cholesterol as its receptor. These studies show for the first time that the undecapeptide of the cholesterol-binding CDCs forms a critical element of the allosteric pathway that controls the assembly of the pore complex. The CDCs are a large family of pathogenesis-associated pore-forming toxins that are expressed by many Gram-positive pathogens. The conserved undecapeptide motif of the CDCs has been regarded as the signature peptide sequence for these toxins, yet its function has remained obscure. The studies herein show that the undecapeptide forms a critical structural element in the allosteric pathway that couples membrane binding to cholesterol to the initiation of distal structural changes, which are required for the assembly of the pore forming complex. These studies provide the first insight into the function of this highly conserved sequence and show that through evolution this pathway is missing in the CD59-binding CDCs.
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40
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Dunstone MA, Tweten RK. Packing a punch: the mechanism of pore formation by cholesterol dependent cytolysins and membrane attack complex/perforin-like proteins. Curr Opin Struct Biol 2012; 22:342-9. [PMID: 22658510 DOI: 10.1016/j.sbi.2012.04.008] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 04/26/2012] [Accepted: 04/26/2012] [Indexed: 11/29/2022]
Abstract
The bacterial cholesterol dependent cytolysins (CDCs) and membrane attack complex/perforin-like proteins (MACPF) represent two major branches of a large, exceptionally diverged superfamily. Most characterized CDC/MACPF proteins form large pores that function in immunity, venoms, and pathogenesis. Extensive structural, biochemical and biophysical studies have started to address some of the questions surrounding how the soluble, monomeric form of these remarkable molecules recognize diverse targets and assemble into oligomeric membrane embedded pores. This review explores mechanistic similarities and differences in how CDCs and MACPF proteins form pores.
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Affiliation(s)
- Michelle A Dunstone
- Department of Biochemistry and Molecular Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia
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Hotze EM, Wilson-Kubalek E, Farrand AJ, Bentsen L, Parker MW, Johnson AE, Tweten RK. Monomer-monomer interactions propagate structural transitions necessary for pore formation by the cholesterol-dependent cytolysins. J Biol Chem 2012; 287:24534-43. [PMID: 22645132 DOI: 10.1074/jbc.m112.380139] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The assembly of the cholesterol-dependent cytolysin (CDC) oligomeric pore complex requires a complex choreography of secondary and tertiary structural changes in domain 3 (D3) of the CDC monomer structure. A point mutation was identified in the archetype CDC, perfringolysin O, that blocks detectable D3 structural changes and traps the membrane-bound monomers in an early and reversible stage of oligomer assembly. Using this and other mutants we show that specific D3 structural changes are propagated from one membrane-bound monomer to another. Propagation of these structural changes results in the exposure of a β-strand in D3 that allows it to pair and form edge-on interactions with a second β-strand of a free membrane-bound monomer. Pairing of these strands establishes the final geometry of the pore complex and is necessary to drive the formation of the β-barrel pore. These studies provide new insights into how structural information is propagated between membrane-bound monomers of a self-assembling system and the interactions that establish the geometry of the final pore complex.
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Affiliation(s)
- Eileen M Hotze
- Department of Microbiology and Immunology, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Hotze EM, Tweten RK. Membrane assembly of the cholesterol-dependent cytolysin pore complex. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:1028-38. [PMID: 21835159 PMCID: PMC3243806 DOI: 10.1016/j.bbamem.2011.07.036] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 07/24/2011] [Indexed: 12/16/2022]
Abstract
The cholesterol-dependent cytolysins (CDCs) are a large family of pore-forming toxins that are produced, secreted and contribute to the pathogenesis of many species of Gram-positive bacteria. The assembly of the CDC pore-forming complex has been under intense study for the past 20 years. These studies have revealed a molecular mechanism of pore formation that exhibits many novel features. The CDCs form large β-barrel pore complexes that are assembled from 35 to 40 soluble CDC monomers. Pore formation is dependent on the presence of membrane cholesterol, which functions as the receptor for most CDCs. Cholesterol binding initiates significant secondary and tertiary structural changes in the monomers, which lead to the assembly of a large membrane embedded β-barrel pore complex. This review will focus on the molecular mechanism of assembly of the CDC membrane pore complex and how these studies have led to insights into the mechanism of pore formation for other pore-forming proteins. This article is part of a Special Issue entitled: Protein Folding in Membranes.
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Affiliation(s)
- Eileen M. Hotze
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Rodney K. Tweten
- Department of Microbiology and Immunology, The University of Oklahoma Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Pleckaityte M, Janulaitiene M, Lasickiene R, Zvirbliene A. Genetic and biochemical diversity of Gardnerella vaginalis strains isolated from women with bacterial vaginosis. ACTA ACUST UNITED AC 2012; 65:69-77. [PMID: 22309200 DOI: 10.1111/j.1574-695x.2012.00940.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 01/31/2012] [Accepted: 01/31/2012] [Indexed: 11/29/2022]
Abstract
Gardnerella vaginalis is considered a substantial player in the progression of bacterial vaginosis (BV). We analysed 17 G. vaginalis strains isolated from the genital tract of women diagnosed with BV to establish a potential link between genotypes/biotypes and the expression of virulence factors, vaginolysin (VLY) and sialidase, which are assumed to play a substantial role in the pathogenesis of BV. Amplified ribosomal DNA restriction analysis revealed two G. vaginalis genotypes. Gardnerella vaginalis isolates of genotype 2 appeared more complex than genotype 1 and were subdivided into three subtypes. Biochemical typing allowed us to distinguish four different biotypes. A great diversity of the level of VLY production among the isolates of G. vaginalis may be related to a different cytotoxicity level of the strains. We did not find any correlation between VLY production level and G. vaginalis genotype/biotype. In contrast, a link between G. vaginalis genotype and sialidase production was established. Our findings on the diversity of VLY expression level in different clinical isolates and linking sialidase activity with the genotype of G. vaginalis could help to evaluate the pathogenic potential of different G. vaginalis strains.
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Gao Y, Shi J, Yuan D, Xu B. Imaging enzyme-triggered self-assembly of small molecules inside live cells. Nat Commun 2012; 3:1033. [PMID: 22929790 PMCID: PMC3521559 DOI: 10.1038/ncomms2040] [Citation(s) in RCA: 356] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 08/01/2012] [Indexed: 12/19/2022] Open
Abstract
Self-assembly of small molecules in water to form nanofibres, besides generating sophisticated biomaterials, promises a simple system inside cells for regulating cellular processes. But lack of a convenient approach for studying the self-assembly of small molecules inside cells hinders the development of such systems. Here we report a method to image enzyme-triggered self-assembly of small molecules inside live cells. After linking a fluorophore to a self-assembly motif to make a precursor, we confirmed by (31)P NMR and rheology that enzyme-triggered conversion of the precursor to a hydrogelator results in the formation of a hydrogel via self-assembly. The imaging contrast conferred by the nanofibres of the hydrogelators allowed the evaluation of intracellular self-assembly, the dynamics and the localization of the nanofibres of the hydrogelators in live cells. This approach explores supramolecular chemistry inside cells and may lead to new insights, processes or materials at the interface of chemistry and biology.
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Affiliation(s)
- Yuan Gao
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA 02453, USA
| | - Junfeng Shi
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA 02453, USA
| | - Dan Yuan
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA 02453, USA
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA 02453, USA
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Jost BH, Lucas EA, Billington SJ, Ratner AJ, McGee DJ. Arcanolysin is a cholesterol-dependent cytolysin of the human pathogen Arcanobacterium haemolyticum. BMC Microbiol 2011; 11:239. [PMID: 22029628 PMCID: PMC3215231 DOI: 10.1186/1471-2180-11-239] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 10/26/2011] [Indexed: 12/20/2022] Open
Abstract
Background Arcanobacterium haemolyticum is an emerging human pathogen that causes pharyngitis, wound infections, and a variety of occasional invasive diseases. Since its initial discovery in 1946, this Gram positive organism has been known to have hemolytic activity, yet no hemolysin has been previously reported. A. haemolyticum also displays variable hemolytic activity on laboratory blood agar that is dependent upon which species the blood is derived. Results Here we describe a cholesterol-dependent cytolysin (CDC) secreted by A. haemolyticum, designated arcanolysin (aln), which is present in all strains (n = 52) tested by DNA dot hybridization. Among the known CDCs, ALN is most closely related to pyolysin (PLO) from Trueperella (formerly Arcanobacterium) pyogenes. The aln probe, however, did not hybridize to DNA from T. pyogenes. The aln open reading frame has a lower mol %G+C (46.7%) than the rest of the A. haemolyticum genome (53.1%) and is flanked by two tRNA genes, consistent with probable acquisition by horizontal transfer. The ALN protein (~ 64 kDa) contains a predicted signal sequence, a putative PEST sequence, and a variant undecapeptide within domain 4, which is typically important for function of the toxins. The gene encoding ALN was cloned and expressed in Escherichia coli as a functional recombinant toxin. Recombinant ALN had hemolytic activity on erythrocytes and cytolytic activity on cultured cells from human, rabbit, pig and horse origins but was poorly active on ovine, bovine, murine, and canine cells. ALN was less sensitive to inhibition by free cholesterol than perfringolysin O, consistent with the presence of the variant undecapeptide. Conclusions ALN is a newly identified CDC with hemolytic activity and unique properties in the CDC family and may be a virulence determinant for A. haemolyticum.
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Affiliation(s)
- B Helen Jost
- Department of Veterinary Science and Microbiology, The University of Arizona, 1117 E Lowell Street, Tucson, AZ 85721, USA
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Wickham SE, Hotze EM, Farrand AJ, Polekhina G, Nero TL, Tomlinson S, Parker MW, Tweten RK. Mapping the intermedilysin-human CD59 receptor interface reveals a deep correspondence with the binding site on CD59 for complement binding proteins C8alpha and C9. J Biol Chem 2011; 286:20952-62. [PMID: 21507937 DOI: 10.1074/jbc.m111.237446] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD59 is a glycosylphosphatidylinositol-anchored protein that inhibits the assembly of the terminal complement membrane attack complex (MAC) pore, whereas Streptococcus intermedius intermedilysin (ILY), a pore forming cholesterol-dependent cytolysin (CDC), specifically binds to human CD59 (hCD59) to initiate the formation of its pore. The identification of the residues of ILY and hCD59 that form their binding interface revealed a remarkably deep correspondence between the hCD59 binding site for ILY and that for the MAC proteins C8α and C9. ILY disengages from hCD59 during the prepore to pore transition, suggesting that loss of this interaction is necessary to accommodate specific structural changes associated with this transition. Consistent with this scenario, mutants of hCD59 or ILY that increased the affinity of this interaction decreased the cytolytic activity by slowing the transition of the prepore to pore but not the assembly of the prepore oligomer. A signature motif was also identified in the hCD59 binding CDCs that revealed a new hCD59-binding member of the CDC family. Although the binding site on hCD59 for ILY, C8α, and C9 exhibits significant homology, no similarity exists in their binding sites for hCD59. Hence, ILY and the MAC proteins interact with common amino acids of hCD59 but lack detectable conservation in their binding sites for hCD59.
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Affiliation(s)
- Stephanie E Wickham
- Department of Microbiology and Immunology, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Moe PC, Heuck AP. Phospholipid Hydrolysis Caused by Clostridium perfringens α-Toxin Facilitates the Targeting of Perfringolysin O to Membrane Bilayers. Biochemistry 2010; 49:9498-507. [DOI: 10.1021/bi1013886] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Paul C. Moe
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Alejandro P. Heuck
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003, United States
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48
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Production and characterization of monoclonal antibodies against vaginolysin: Mapping of a region critical for its cytolytic activity. Toxicon 2010; 56:19-28. [DOI: 10.1016/j.toxicon.2010.03.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 02/05/2010] [Accepted: 03/08/2010] [Indexed: 11/21/2022]
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Harris JR, Lewis RJ, Baik C, Pokrajac L, Billington SJ, Palmer M. Cholesterol microcrystals and cochleate cylinders: attachment of pyolysin oligomers and domain 4. J Struct Biol 2010; 173:38-45. [PMID: 20682347 DOI: 10.1016/j.jsb.2010.07.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 07/16/2010] [Accepted: 07/27/2010] [Indexed: 11/15/2022]
Abstract
Using an established organic solvent injection procedure for the preparation of aqueous cholesterol microcrystal suspensions, it has now been shown that a new, hollow, cylindrical, tightly-coiled, multi-bilayer form of cholesterol can be generated, termed the cochleate cylinder. Cholesterol cochleate cylinders are formed in larger numbers at intermediate temperatures (40-75°C) but are not formed at 100°C. The structure of the cholesterol microcrystals and cochleate cylinders is shown in negatively stained electron micrographs. Oligomerization and attachment of pyolysin to cholesterol microcrystals and cochleate cylinders is shown, as is the attachment of the pyolysin "cholesterol-binding" domain 4 (D4) fragment. The bound D4 domain forms a linear array on the two planar surfaces and edges of the cholesterol microcrystals and a quasi helical array on the surface of the cochleate cylinders. Little evidence has been obtained to support the possibility that interaction or hetero-oligomerization can occur between intact pyolysin and the pyolysin D4 fragment on the surface of cholesterol microcrystals. Using immobilized cholesterol crystals attached to a carbon support film, single-sided linear labelling of the cholesterol surface with pyolysin D4 has been achieved, which correlates well with the images from the microcrystal suspensions and our earlier data using non-cytolytic streptolysin O mutants.
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Affiliation(s)
- J Robin Harris
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle-upon-Tyne NE2 4HH, UK.
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50
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Popoff MR, Poulain B. Bacterial toxins and the nervous system: neurotoxins and multipotential toxins interacting with neuronal cells. Toxins (Basel) 2010; 2:683-737. [PMID: 22069606 PMCID: PMC3153206 DOI: 10.3390/toxins2040683] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 03/18/2010] [Accepted: 04/07/2010] [Indexed: 12/13/2022] Open
Abstract
Toxins are potent molecules used by various bacteria to interact with a host organism. Some of them specifically act on neuronal cells (clostridial neurotoxins) leading to characteristics neurological affections. But many other toxins are multifunctional and recognize a wider range of cell types including neuronal cells. Various enterotoxins interact with the enteric nervous system, for example by stimulating afferent neurons or inducing neurotransmitter release from enterochromaffin cells which result either in vomiting, in amplification of the diarrhea, or in intestinal inflammation process. Other toxins can pass the blood brain barrier and directly act on specific neurons.
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Affiliation(s)
- Michel R. Popoff
- Neurotransmission et Sécrétion Neuroendocrine, CNRS UPR 2356 IFR 37 - Neurosciences, Centre de Neurochimie, 5, rue Blaise Pascal, F-67084 STRASBOURG cedex, France;
- Author to whom correspondence should be addressed;
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