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Pedrera L, Ros U, Fanani ML, Lanio ME, Epand RM, García-Sáez AJ, Álvarez C. The Important Role of Membrane Fluidity on the Lytic Mechanism of the α-Pore-Forming Toxin Sticholysin I. Toxins (Basel) 2023; 15:80. [PMID: 36668899 PMCID: PMC9865829 DOI: 10.3390/toxins15010080] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 01/19/2023] Open
Abstract
Actinoporins have emerged as archetypal α-pore-forming toxins (PFTs) that promote the formation of pores in membranes upon oligomerization and insertion of an α-helix pore-forming domain in the bilayer. These proteins have been used as active components of immunotoxins, therefore, understanding their lytic mechanism is crucial for developing this and other applications. However, the mechanism of how the biophysical properties of the membrane modulate the properties of pores generated by actinoporins remains unclear. Here we studied the effect of membrane fluidity on the permeabilizing activity of sticholysin I (St I), a toxin that belongs to the actinoporins family of α-PFTs. To modulate membrane fluidity we used vesicles made of an equimolar mixture of phosphatidylcholine (PC) and egg sphingomyelin (eggSM), in which PC contained fatty acids of different acyl chain lengths and degrees of unsaturation. Our detailed single-vesicle analysis revealed that when membrane fluidity is high, most of the vesicles are partially permeabilized in a graded manner. In contrast, more rigid membranes can be either completely permeabilized or not, indicating an all-or-none mechanism. Altogether, our results reveal that St I pores can be heterogeneous in size and stability, and that these properties depend on the fluid state of the lipid bilayer. We propose that membrane fluidity at different regions of cellular membranes is a key factor to modulate the activity of the actinoporins, which has implications for the design of different therapeutic strategies based on their lytic action.
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Affiliation(s)
- Lohans Pedrera
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, La Habana CP 10400, Cuba
- Institute for Genetics and CECAD Cluster of Excellence, University of Cologne, Joseph-Stelzmann-Straße 26, 50931 Cologne, Germany
| | - Uris Ros
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, La Habana CP 10400, Cuba
- Institute for Genetics and CECAD Cluster of Excellence, University of Cologne, Joseph-Stelzmann-Straße 26, 50931 Cologne, Germany
| | - Maria Laura Fanani
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Facultad de Ciencias Químicas-CONICET, Córdoba X5000HUA, Argentina
| | - María E. Lanio
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, La Habana CP 10400, Cuba
| | - Richard M. Epand
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Ana J. García-Sáez
- Institute for Genetics and CECAD Cluster of Excellence, University of Cologne, Joseph-Stelzmann-Straße 26, 50931 Cologne, Germany
| | - Carlos Álvarez
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, La Habana CP 10400, Cuba
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Palacios-Ortega J, Amigot-Sánchez R, García-Montoya C, Gorše A, Heras-Márquez D, García-Linares S, Martínez-del-Pozo Á, Slotte JP. Determination of the boundary lipids of sticholysins using tryptophan quenching. Sci Rep 2022; 12:17328. [PMID: 36243747 PMCID: PMC9569322 DOI: 10.1038/s41598-022-21750-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/30/2022] [Indexed: 01/10/2023] Open
Abstract
Sticholysins are α-pore-forming toxins produced by the sea-anemone Stichodactyla helianthus. These toxins exert their activity by forming pores on sphingomyelin-containing membranes. Recognition of sphingomyelin by sticholysins is required to start the process of pore formation. Sphingomyelin recognition is coupled with membrane binding and followed by membrane penetration and oligomerization. Many features of these processes are known. However, the extent of contact with each of the different kinds of lipids present in the membrane has received little attention. To delve into this question, we have used a phosphatidylcholine analogue labeled at one of its acyl chains with a doxyl moiety, a known quencher of tryptophan emission. Here we present evidence for the contact of sticholysins with phosphatidylcholine lipids in the sticholysin oligomer, and for how each sticholysin isotoxin is affected differently by the inclusion of cholesterol in the membrane. Furthermore, using phosphatidylcholine analogs that were labeled at different positions of their structure (acyl chains and headgroup) in combination with a variety of sticholysin mutants, we also investigated the depth of the tryptophan residues of sticholysins in the bilayer. Our results indicate that the position of the tryptophan residues relative to the membrane normal is deeper when cholesterol is absent from the membrane.
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Affiliation(s)
- Juan Palacios-Ortega
- grid.13797.3b0000 0001 2235 8415Biochemistry Department, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland ,grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - Rafael Amigot-Sánchez
- grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - Carmen García-Montoya
- grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - Ana Gorše
- grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - Diego Heras-Márquez
- grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - Sara García-Linares
- grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - Álvaro Martínez-del-Pozo
- grid.4795.f0000 0001 2157 7667Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | - J. Peter Slotte
- grid.13797.3b0000 0001 2235 8415Biochemistry Department, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
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Ulhuq FR, Mariano G. Bacterial pore-forming toxins. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001154. [PMID: 35333704 PMCID: PMC9558359 DOI: 10.1099/mic.0.001154] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/03/2022] [Indexed: 12/11/2022]
Abstract
Pore-forming toxins (PFTs) are widely distributed in both Gram-negative and Gram-positive bacteria. PFTs can act as virulence factors that bacteria utilise in dissemination and host colonisation or, alternatively, they can be employed to compete with rival microbes in polymicrobial niches. PFTs transition from a soluble form to become membrane-embedded by undergoing large conformational changes. Once inserted, they perforate the membrane, causing uncontrolled efflux of ions and/or nutrients and dissipating the protonmotive force (PMF). In some instances, target cells intoxicated by PFTs display additional effects as part of the cellular response to pore formation. Significant progress has been made in the mechanistic description of pore formation for the different PFTs families, but in several cases a complete understanding of pore structure remains lacking. PFTs have evolved recognition mechanisms to bind specific receptors that define their host tropism, although this can be remarkably diverse even within the same family. Here we summarise the salient features of PFTs and highlight where additional research is necessary to fully understand the mechanism of pore formation by members of this diverse group of protein toxins.
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Affiliation(s)
- Fatima R. Ulhuq
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
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Donato M, Soto C, Lanio ME, Itri R, Álvarez C. The pore-forming activity of sticholysin I is enhanced by the presence of a phospholipid hydroperoxide in membrane. Toxicon 2021; 204:44-55. [PMID: 34736955 DOI: 10.1016/j.toxicon.2021.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/23/2021] [Accepted: 10/29/2021] [Indexed: 11/19/2022]
Abstract
Sticholysin I (StI) is a pore-forming toxin (PFT) belonging to the actinoporin protein family characterized by high permeabilizing activity in membranes. StI readily associates with sphingomyelin (SM)-containing membranes originating pores that can lead to cell death. Binding and pore-formation are critically dependent on the physicochemical properties of membrane. 1-palmitoyl-2-oleoylphosphatidylcholine hydroperoxide (POPC-OOH) is an oxidized phospholipid (OxPL) containing an -OOH moiety in the unsaturated hydrocarbon chain which orientates towards the bilayer interface. This orientation causes an increase in the lipid molecular area, lateral expansion and decrease in bilayer thickness, elastic and bending modulus, as well as modification of lipid packing. Taking advantage of membrane structural changes promoted by POPC-OOH, we investigated its influence on the permeabilizing ability of StI. Here we report the action of StI on Giant Unilamellar Vesicles (GUVs) made of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and SM containing increasing amount of POPC-OOH to assess vesicle permeability changes when compared to OxPL-lacking membranes. Inclusion of POPC-OOH in membranes did not promote spontaneous vesicle leaking but resulted in increased membrane permeability due to StI action. StI activity did not modify the fluid-gel phase coexistence boundaries neither in POPC:SM or POPC-OOH:SM membranes. However, the StI insertion mechanism in membrane seems to differ between POPC:SM and POPC-OOH:SM mixtures as suggested by changes in the time course of monolayer surface tension measurements, even though a preferable binding of the toxin to OxPL-containing systems could not be here demonstrated. In summary, modifications in the membrane imposed by lipid hydroperoxidation favor StI permeabilizing activity.
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Affiliation(s)
- Maressa Donato
- Instituto de Física, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Center for Laser and Applications, Nuclear and Energy Research Institute, São Paulo, Brazil
| | - Carmen Soto
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, CP, 10400, La Habana, Cuba
| | - María Eliana Lanio
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, CP, 10400, La Habana, Cuba
| | - Rosangela Itri
- Instituto de Física, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
| | - Carlos Álvarez
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana, CP, 10400, La Habana, Cuba.
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Kulma M, Anderluh G. Beyond pore formation: reorganization of the plasma membrane induced by pore-forming proteins. Cell Mol Life Sci 2021; 78:6229-6249. [PMID: 34387717 PMCID: PMC11073440 DOI: 10.1007/s00018-021-03914-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/09/2021] [Accepted: 08/03/2021] [Indexed: 12/23/2022]
Abstract
Pore-forming proteins (PFPs) are a heterogeneous group of proteins that are expressed and secreted by a wide range of organisms. PFPs are produced as soluble monomers that bind to a receptor molecule in the host cell membrane. They then assemble into oligomers that are incorporated into the lipid membrane to form transmembrane pores. Such pore formation alters the permeability of the plasma membrane and is one of the most common mechanisms used by PFPs to destroy target cells. Interestingly, PFPs can also indirectly manipulate diverse cellular functions. In recent years, increasing evidence indicates that the interaction of PFPs with lipid membranes is not only limited to pore-induced membrane permeabilization but is also strongly associated with extensive plasma membrane reorganization. This includes lateral rearrangement and deformation of the lipid membrane, which can lead to the disruption of target cell function and finally death. Conversely, these modifications also constitute an essential component of the membrane repair system that protects cells from the lethal consequences of pore formation. Here, we provide an overview of the current knowledge on the changes in lipid membrane organization caused by PFPs from different organisms.
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Affiliation(s)
- Magdalena Kulma
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia
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Alvarez C, Soto C, Cabezas S, Alvarado-Mesén J, Laborde R, Pazos F, Ros U, Hernández AM, Lanio ME. Panorama of the Intracellular Molecular Concert Orchestrated by Actinoporins, Pore-Forming Toxins from Sea Anemones. Toxins (Basel) 2021; 13:toxins13080567. [PMID: 34437438 PMCID: PMC8402351 DOI: 10.3390/toxins13080567] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 12/25/2022] Open
Abstract
Actinoporins (APs) are soluble pore-forming proteins secreted by sea anemones that experience conformational changes originating in pores in the membranes that can lead to cell death. The processes involved in the binding and pore-formation of members of this protein family have been deeply examined in recent years; however, the intracellular responses to APs are only beginning to be understood. Unlike pore formers of bacterial origin, whose intracellular impact has been studied in more detail, currently, we only have knowledge of a few poorly integrated elements of the APs’ intracellular action. In this review, we present and discuss an updated landscape of the studies aimed at understanding the intracellular pathways triggered in response to APs attack with particular reference to sticholysin II, the most active isoform produced by the Caribbean Sea anemone Stichodactyla helianthus. To achieve this, we first describe the major alterations these cytolysins elicit on simpler cells, such as non-nucleated mammalian erythrocytes, and then onto more complex eukaryotic cells, including tumor cells. This understanding has provided the basis for the development of novel applications of sticholysins such as the construction of immunotoxins directed against undesirable cells, such as tumor cells, and the design of a cancer vaccine platform. These are among the most interesting potential uses for the members of this toxin family that have been carried out in our laboratory.
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Affiliation(s)
- Carlos Alvarez
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
- Correspondence:
| | - Carmen Soto
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
| | - Sheila Cabezas
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
| | - Javier Alvarado-Mesén
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
- Escuela de Ciencias Biológicas, Universidad Nacional, Heredia 40101, Costa Rica
| | - Rady Laborde
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
| | - Fabiola Pazos
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
| | - Uris Ros
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-strasse 26, 50931 Cologne, Germany
| | - Ana María Hernández
- Immunobiology Division, Molecular Immunology Institute, Center of Molecular Immunology (CIM), Playa, Havana CP 11600, Cuba;
| | - María Eliana Lanio
- Centro de Estudio de Proteínas, Facultad de Biología, Universidad de La Habana (UH) and Laboratorio UH-Centro de Inmunología Molecular, Havana CP 11600, Cuba; (C.S.); (S.C.); (J.A.-M.); (R.L.); (F.P.); (U.R.); (M.E.L.)
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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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Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Heras-Márquez D, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á. Structural foundations of sticholysin functionality. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140696. [PMID: 34246789 DOI: 10.1016/j.bbapap.2021.140696] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 01/22/2023]
Abstract
Actinoporins constitute a family of α pore-forming toxins produced by sea anemones. The soluble fold of these proteins consists of a β-sandwich flanked by two α-helices. Actinoporins exert their activity by specifically recognizing sphingomyelin at their target membranes. Once there, they penetrate the membrane with their N-terminal α-helices, a process that leads to the formation of cation-selective pores. These pores kill the target cells by provoking an osmotic shock on them. In this review, we examine the role and relevance of the structural features of actinoporins, down to the residue level. We look at the specific amino acids that play significant roles in the function of actinoporins and their fold. Particular emphasis is given to those residues that display a high degree of conservation across the actinoporin sequences known to date. In light of the latest findings in the field, the membrane requirements for pore formation, the effect of lipid composition, and the process of pore formation are also discussed.
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Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - Esperanza Rivera-de-Torre
- Department of Biochemistry and Biotechnology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Diego Heras-Márquez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
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Pore-forming proteins: From defense factors to endogenous executors of cell death. Chem Phys Lipids 2020; 234:105026. [PMID: 33309552 DOI: 10.1016/j.chemphyslip.2020.105026] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023]
Abstract
Pore-forming proteins (PFPs) and small antimicrobial peptides (AMPs) represent a large family of molecules with the common ability to punch holes in cell membranes to alter their permeability. They play a fundamental role as infectious bacteria's defensive tools against host's immune system and as executors of endogenous machineries of regulated cell death in eukaryotic cells. Despite being highly divergent in primary sequence and 3D structure, specific folds of pore-forming domains have been conserved. In fact, pore formation is considered an ancient mechanism that takes place through a general multistep process involving: membrane partitioning and insertion, oligomerization and pore formation. However, different PFPs and AMPs assemble and form pores following different mechanisms that could end up either in the formation of protein-lined or protein-lipid pores. In this review, we analyze the current findings in the mechanism of action of different PFPs and AMPs that support a wide role of membrane pore formation in nature. We also provide the newest insights into the development of state-of-art techniques that have facilitated the characterization of membrane pores. To understand the physiological role of these peptides/proteins or develop clinical applications, it is essential to uncover the molecular mechanism of how they perforate membranes.
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Functional and Structural Variation among Sticholysins, Pore-Forming Proteins from the Sea Anemone Stichodactyla helianthus. Int J Mol Sci 2020; 21:ijms21238915. [PMID: 33255441 PMCID: PMC7727798 DOI: 10.3390/ijms21238915] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/15/2022] Open
Abstract
Venoms constitute complex mixtures of many different molecules arising from evolution in processes driven by continuous prey-predator interactions. One of the most common compounds in these venomous cocktails are pore-forming proteins, a family of toxins whose activity relies on the disruption of the plasmatic membranes by forming pores. The venom of sea anemones, belonging to the oldest lineage of venomous animals, contains a large amount of a characteristic group of pore-forming proteins known as actinoporins. They bind specifically to sphingomyelin-containing membranes and suffer a conformational metamorphosis that drives them to make pores. This event usually leads cells to death by osmotic shock. Sticholysins are the actinoporins produced by Stichodactyla helianthus. Three different isotoxins are known: Sticholysins I, II, and III. They share very similar amino acid sequence and three-dimensional structure but display different behavior in terms of lytic activity and ability to interact with cholesterol, an important lipid component of vertebrate membranes. In addition, sticholysins can act in synergy when exerting their toxin action. The subtle, but important, molecular nuances that explain their different behavior are described and discussed throughout the text. Improving our knowledge about sticholysins behavior is important for eventually developing them into biotechnological tools.
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Evaluation of different approaches used to study membrane permeabilization by actinoporins on model lipid vesicles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183311. [DOI: 10.1016/j.bbamem.2020.183311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/12/2020] [Accepted: 04/13/2020] [Indexed: 02/01/2023]
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Ramírez-Carreto S, Miranda-Zaragoza B, Rodríguez-Almazán C. Actinoporins: From the Structure and Function to the Generation of Biotechnological and Therapeutic Tools. Biomolecules 2020; 10:E539. [PMID: 32252469 PMCID: PMC7226409 DOI: 10.3390/biom10040539] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/19/2020] [Accepted: 03/21/2020] [Indexed: 12/22/2022] Open
Abstract
Actinoporins (APs) are a family of pore-forming toxins (PFTs) from sea anemones. These biomolecules exhibit the ability to exist as soluble monomers within an aqueous medium or as constitutively open oligomers in biological membranes. Through their conformational plasticity, actinoporins are considered good candidate molecules to be included for the rational design of molecular tools, such as immunotoxins directed against tumor cells and stochastic biosensors based on nanopores to analyze unique DNA or protein molecules. Additionally, the ability of these proteins to bind to sphingomyelin (SM) facilitates their use for the design of molecular probes to identify SM in the cells. The immunomodulatory activity of actinoporins in liposomal formulations for vaccine development has also been evaluated. In this review, we describe the potential of actinoporins for use in the development of molecular tools that could be used for possible medical and biotechnological applications.
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Affiliation(s)
| | | | - Claudia Rodríguez-Almazán
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Cuernavaca, Morelos 62210, Mexico; (S.R.-C.); (B.M.-Z.)
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Pore-forming toxins from sea anemones: from protein-membrane interaction to its implications for developing biomedical applications. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2020. [DOI: 10.1016/bs.abl.2020.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Mesa-Galloso H, Valiente PA, Valdés-Tresanco ME, Epand RF, Lanio ME, Epand RM, Alvarez C, Tieleman DP, Ros U. Membrane Remodeling by the Lytic Fragment of SticholysinII: Implications for the Toroidal Pore Model. Biophys J 2019; 117:1563-1576. [PMID: 31587828 DOI: 10.1016/j.bpj.2019.09.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/07/2019] [Accepted: 09/09/2019] [Indexed: 01/15/2023] Open
Abstract
Sticholysins are pore-forming toxins of biomedical interest and represent a prototype of proteins acting through the formation of protein-lipid or toroidal pores. Peptides spanning the N-terminus of sticholysins can mimic their permeabilizing activity and, together with the full-length toxins, have been used as a tool to understand the mechanism of pore formation in membranes. However, the lytic mechanism of these peptides and the lipid shape modulating their activity are not completely clear. In this article, we combine molecular dynamics simulations and experimental biophysical tools to dissect different aspects of the pore-forming mechanism of StII1-30, a peptide derived from the N-terminus of sticholysin II (StII). With this combined approach, membrane curvature induction and flip-flop movement of the lipids were identified as two important membrane remodeling steps mediated by StII1-30. Pore formation by this peptide was enhanced by the presence of the negatively curved lipid phosphatidylethanolamine in membranes. This lipid emerged not only as a facilitator of membrane interactions but also as a structural element of the StII1-30 pore that is recruited to the ring upon its assembly. Collectively, these, to our knowledge, new findings support a toroidal model for the architecture of the pore formed by StII1-30 and provide new molecular insight into the role of phosphatidylethanolamine as a membrane component that can easily integrate into the ring of toroidal pores, thus probably aiding in their stabilization. This study contributes to a better understanding of the molecular mechanism underlying the permeabilizing activity of StII1-30 and peptides or proteins acting via a toroidal pore mechanism and offers an informative framework for the optimization of the biomedical application of this and similar molecules.
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Affiliation(s)
- Haydee Mesa-Galloso
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta, Canada; Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Pedro A Valiente
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Mario E Valdés-Tresanco
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta, Canada; Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Raquel F Epand
- Department of Biochemistry and Biomedical Sciences, Health Science Center, McMaster University, Hamilton, Ontario, Canada
| | - Maria E Lanio
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, Health Science Center, McMaster University, Hamilton, Ontario, Canada
| | - Carlos Alvarez
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba
| | - D Peter Tieleman
- Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta, Canada.
| | - Uris Ros
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana, Cuba; Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany.
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Pore-Forming Proteins from Cnidarians and Arachnids as Potential Biotechnological Tools. Toxins (Basel) 2019; 11:toxins11060370. [PMID: 31242582 PMCID: PMC6628452 DOI: 10.3390/toxins11060370] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/18/2019] [Accepted: 06/21/2019] [Indexed: 12/31/2022] Open
Abstract
Animal venoms are complex mixtures of highly specialized toxic molecules. Cnidarians and arachnids produce pore-forming proteins (PFPs) directed against the plasma membrane of their target cells. Among PFPs from cnidarians, actinoporins stand out for their small size and molecular simplicity. While native actinoporins require only sphingomyelin for membrane binding, engineered chimeras containing a recognition antibody-derived domain fused to an actinoporin isoform can nonetheless serve as highly specific immunotoxins. Examples of such constructs targeted against malignant cells have been already reported. However, PFPs from arachnid venoms are less well-studied from a structural and functional point of view. Spiders from the Latrodectus genus are professional insect hunters that, as part of their toxic arsenal, produce large PFPs known as latrotoxins. Interestingly, some latrotoxins have been identified as potent and highly-specific insecticides. Given the proteinaceous nature of these toxins, their promising future use as efficient bioinsecticides is discussed throughout this Perspective. Protein engineering and large-scale recombinant production are critical steps for the use of these PFPs as tools to control agriculturally important insect pests. In summary, both families of PFPs, from Cnidaria and Arachnida, appear to be molecules with promising biotechnological applications.
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Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Gavilanes JG, Martínez-Del-Pozo Á, Slotte JP. Sticholysin, Sphingomyelin, and Cholesterol: A Closer Look at a Tripartite Interaction. Biophys J 2019; 116:2253-2265. [PMID: 31146924 DOI: 10.1016/j.bpj.2019.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/05/2019] [Accepted: 05/10/2019] [Indexed: 02/06/2023] Open
Abstract
Actinoporins are a group of soluble toxic proteins that bind to membranes containing sphingomyelin (SM) and oligomerize to form pores. Sticholysin II (StnII) is a member of the actinoporin family produced by Stichodactyla helianthus. Cholesterol (Chol) is known to enhance the activity of StnII. However, the molecular mechanisms behind this activation have remained obscure, although the activation is not Chol specific but rather sterol specific. To further explore how bilayer lipids affect or are affected by StnII, we have used a multiprobe approach (fluorescent analogs of both Chol and SM) in combination with a series of StnII tryptophan (Trp) mutants to study StnII/bilayer interactions. First, we compared StnII bilayer permeabilization in the presence of Chol or oleoyl-ceramide (OCer). The comparison was done because both Chol and OCer have a 1-hydroxyl, which helps to orient the molecule in the bilayer (although OCer has additional polar functional groups). Both Chol and OCer also have increased affinity for SM, which StnII may recognize. However, our results show that only Chol was able to activate StnII-induced bilayer permeabilization; OCer failed to activate it. To further examine possible Chol/StnII interactions, we measured Förster resonance energy transfer between Trp in StnII and cholestatrienol, a fluorescent analog of Chol. We could show higher Förster resonance energy transfer efficiency between cholestatrienol and Trps in position 100 and 114 of StnII when compared to three other Trp positions further away from the bilayer binding region of StnII. Taken together, our results suggest that StnII was able to attract Chol to its vicinity, maybe by showing affinity for Chol. SM interactions are known to be important for StnII binding to bilayers, and Chol is known to facilitate subsequent permeabilization of the bilayers by StnII. Our results help to better understand the role of these important membrane lipids for the bilayer properties of StnII.
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Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | | | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | | | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
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17
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Carretero GPB, Vicente EF, Cilli EM, Alvarez CM, Jenssen H, Schreier S. Dissecting the mechanism of action of actinoporins. Role of the N-terminal amphipathic α-helix in membrane binding and pore activity of sticholysins I and II. PLoS One 2018; 13:e0202981. [PMID: 30161192 PMCID: PMC6117003 DOI: 10.1371/journal.pone.0202981] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/13/2018] [Indexed: 11/19/2022] Open
Abstract
Actinoporins sticholysin I and sticholysin II (St I, St II) are proposed to lyse model and biomembranes via toroidal pore formation by their N-terminal domain. Based on the hypothesis that peptide fragments can reproduce the structure and function of this domain, the behavior of peptides containing St I residues 12–31 (StI12-31), St II residues 11–30 (StII11-30), and its TOAC-labeled analogue (N-TOAC-StII11-30) was examined. Molecular modeling showed a good match with experimental structures, indicating amphipathic α-helices in the same regions as in the toxins. CD spectra revealed that the peptides were essentially unstructured in aqueous solution, acquiring α-helical conformation upon interaction with micelles and large unilamellar vesicles (LUV) of variable lipid composition. Fluorescence quenching studies with NBD-containing lipids indicated that N-TOAC-StII11-30’s nitroxide moiety is located in the membranes polar head group region. Pyrene-labeled phospholipid inter-leaflet redistribution suggested that the peptides form toroidal pores, according to the mechanism of action proposed for the toxins. Binding occurred only to negatively charged LUV, indicating the importance of electrostatic interactions; in contrast the peptides bound to both negatively charged and zwitterionic micelles, pointing to a lesser influence of these interactions. In addition, differences between bilayers and micelles in head group packing and in curvature led to differences in peptide-membrane interaction. We propose that the peptides topography in micelles resembles that of the toxins in the toroidal pore. The peptides mimicked the toxins permeabilizing activity, St II peptides being more effective than StI12-31. To our knowledge, this is the first demonstration that differences in the toxins N-terminal amphipathic α-helix play a role in the difference between St I and St II activities.
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Affiliation(s)
- Gustavo P. B. Carretero
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Eduardo F. Vicente
- Faculty of Science and Engineering, State University of São Paulo, Tupã, Brazil
| | - Eduardo M. Cilli
- Institute of Chemistry, State University of São Paulo, Araraquara, Brazil
| | | | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Shirley Schreier
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
- * E-mail:
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Cloning, purification and characterization of nigrelysin, a novel actinoporin from the sea anemone Anthopleura nigrescens. Biochimie 2018; 156:206-223. [PMID: 30036605 DOI: 10.1016/j.biochi.2018.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 07/19/2018] [Indexed: 12/15/2022]
Abstract
Actinoporins constitute a unique class of pore-forming toxins found in sea anemones that being secreted as soluble monomers are able to bind and permeabilize membranes leading to cell death. The interest in these proteins has risen due to their high cytotoxicity that can be properly used to design immunotoxins against tumor cells and antigen-releasing systems to cell cytosol. In this work we describe a novel actinoporin produced by Anthopleura nigrescens, an anemone found in the Central American Pacific Ocean. Here we report the amino acid sequence of an actinoporin as deduced from cDNA obtained from total body RNA. The synthetic DNA sequence encoding for one cytolysin variant was expressed in BL21 Star (DE3) Escherichia coli and the protein purified by chromatography on CM Sephadex C-25 with more than 97% homogeneity as verified by MS-MS and HPLC analyses. This actinoporin comprises 179 amino acid residues, consistent with its observed isotope-averaged molecular mass of 19 661 Da. The toxin lacks Cys and readily permeabilizes erythrocytes, as well as L1210 cells. CD spectroscopy revealed that its secondary structure is dominated by beta structure (58.5%) with 5.5% of α-helix, and 35% of random structure. Moreover, binding experiments to lipidic monolayers and to liposomes, as well as permeabilization studies in vesicles, revealed that the affinity of this toxin for sphingomyelin-containing membranes is quite similar to sticholysin II (StII). Comparison by spectroscopic techniques and modeling the three-dimensional structure of nigrelysin (Ng) showed a high homology with StII but several differences were also detectable. Taken together, these results reinforce the notion that Ng is a novel member of the actinoporin pore-forming toxin (PFT) family with a HA as high as that of StII, the most potent actinoporin so far described, but with peculiar structural characteristics contributing to expand the understanding of the structure-function relationship in this protein family.
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Leychenko E, Isaeva M, Tkacheva E, Zelepuga E, Kvetkina A, Guzev K, Monastyrnaya M, Kozlovskaya E. Multigene Family of Pore-Forming Toxins from Sea Anemone Heteractis crispa. Mar Drugs 2018; 16:E183. [PMID: 29794988 PMCID: PMC6025637 DOI: 10.3390/md16060183] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/21/2018] [Accepted: 05/22/2018] [Indexed: 11/23/2022] Open
Abstract
Sea anemones produce pore-forming toxins, actinoporins, which are interesting as tools for cytoplasmic membranes study, as well as being potential therapeutic agents for cancer therapy. This investigation is devoted to structural and functional study of the Heteractis crispa actinoporins diversity. Here, we described a multigene family consisting of 47 representatives expressed in the sea anemone tentacles as prepropeptide-coding transcripts. The phylogenetic analysis revealed that actinoporin clustering is consistent with the division of sea anemones into superfamilies and families. The transcriptomes of both H. crispa and Heteractis magnifica appear to contain a large repertoire of similar genes representing a rapid expansion of the actinoporin family due to gene duplication and sequence divergence. The presence of the most abundant specific group of actinoporins in H. crispa is the major difference between these species. The functional analysis of six recombinant actinoporins revealed that H. crispa actinoporin grouping was consistent with the different hemolytic activity of their representatives. According to molecular modeling data, we assume that the direction of the N-terminal dipole moment tightly reflects the actinoporins' ability to possess hemolytic activity.
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Affiliation(s)
- Elena Leychenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
- School of Natural Sciences, Far Eastern Federal University, Sukhanova Street 8, Vladivostok 690091, Russia.
| | - Marina Isaeva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
- School of Natural Sciences, Far Eastern Federal University, Sukhanova Street 8, Vladivostok 690091, Russia.
| | - Ekaterina Tkacheva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Elena Zelepuga
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Aleksandra Kvetkina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Konstantin Guzev
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Margarita Monastyrnaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Emma Kozlovskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
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Soto C, Bergado G, Blanco R, Griñán T, Rodríguez H, Ros U, Pazos F, Lanio ME, Hernández AM, Álvarez C. Sticholysin II-mediated cytotoxicity involves the activation of regulated intracellular responses that anticipates cell death. Biochimie 2018; 148:18-35. [DOI: 10.1016/j.biochi.2018.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/07/2018] [Indexed: 12/12/2022]
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Self-homodimerization of an actinoporin by disulfide bridging reveals implications for their structure and pore formation. Sci Rep 2018; 8:6614. [PMID: 29700324 PMCID: PMC5920107 DOI: 10.1038/s41598-018-24688-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/04/2018] [Indexed: 11/17/2022] Open
Abstract
The Trp111 to Cys mutant of sticholysin I, an actinoporin from Stichodactyla helianthus sea anemone, forms a homodimer via a disulfide bridge. The purified dimer is 193 times less hemolytic than the monomer. Ultracentrifugation, dynamic light scattering and size-exclusion chromatography demonstrate that monomers and dimers are the only independent oligomeric states encountered. Indeed, circular dichroism and fluorescence spectroscopies showed that Trp/Tyr residues participate in homodimerization and that the dimer is less thermostable than the monomer. A homodimer three-dimensional model was constructed and indicates that Trp147/Tyr137 are at the homodimer interface. Spectroscopy results validated the 3D-model and assigned 85° to the disulfide bridge dihedral angle responsible for dimerization. The homodimer model suggests that alterations in the membrane/carbohydrate-binding sites in one of the monomers, as result of dimerization, could explain the decrease in the homodimer ability to form pores.
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Peptide fingerprinting of the sea anemone Heteractis magnifica mucus revealed neurotoxins, Kunitz-type proteinase inhibitors and a new β-defensin α-amylase inhibitor. J Proteomics 2017; 173:12-21. [PMID: 29191747 DOI: 10.1016/j.jprot.2017.11.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 01/01/2023]
Abstract
Sea anemone mucus, due to its multiple and vital functions, is a valuable substance for investigation of new biologically active peptides. In this work, compounds of Heteractis magnifica mucus were separated by multistage liquid chromatography and resulting fractions were analyzed by MALDI-TOF MS. Peptide maps constructed according to the molecular masses and hydrophobicity showed presence of 326 both new and known peptides. Several major peptides from mucus were identified, including the sodium channel toxin RpII isolated earlier from H. magnifica, and four Kunitz-type proteinase inhibitors identical to H. crispa ones. Kunitz-type transcript diversity was studied and sequences of mature peptides were deduced. New β-defensin α-amylase inhibitor, a homolog of helianthamide from Stichodactyla helianthus, was isolated and structurally characterized. Overall, H. magnifica is a source of biologically active peptides with great pharmacological potential. BIOLOGICAL SIGNIFICANCE Proteinase and α-amylase inhibitors along with toxins are major components of H. magnifica mucus which play an important role in the successful existence of sea anemones. Obtained peptide maps create a basis for more accurate identification of peptides during future transcriptomic/genomic studies of sea anemone H. magnifica.
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Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Gavilanes JG, Martínez-Del-Pozo Á, Slotte JP. Differential Effect of Bilayer Thickness on Sticholysin Activity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11018-11027. [PMID: 28933861 DOI: 10.1021/acs.langmuir.7b01765] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, we examined the influence of bilayer thickness on the activity of the actinoporin toxins sticholysin I and II (StnI and StnII) at 25 °C. Bilayer thickness was varied using dimonounsaturated phosphatidylcholine (PC) analogues (with 14:1, 16:1, 18:1, 20:1, and 22:1 acyl chains). In addition, N-14:0-sphingomyelin (SM) was always included because StnI and StnII are SM specific. Cholesterol was also incorporated as indicated. In cholesterol-free large unilamellar vesicles (LUVs) the PC:SM molar ratio was 4:1, and when cholesterol was included, the complete molar ratio was 4:1:0.5 (PC:SM:cholesterol, respectively). Stn toxins promote bilayer leakage through pores formed by oligomerized toxin monomers. Initial calcein leakage was moderately dependent on bilayer PC acyl chain length (and thus bilayer thickness), with higher rates observed with di-16:1 and di-18:1 PC bilayers. In the presence of cholesterol, the maximum rates of calcein leakage were observed in di-14:1 and di-16:1 PC bilayers. Using isothermal titration calorimetry to study the Stn-LUV interaction, we observed that the bilayer affinity constant (Ka) peaked with LUVs containing di-18:1 PC, and was lower in shorter and longer PC acyl chain bilayers. The presence of cholesterol increased the binding affinity approximately 30-fold at the optimal bilayer thickness (di-18:1-PC). We conclude that bilayer thickness affects both functional and conformational aspects of Stn membrane binding and pore formation. Moreover, the length of the actinoporins' N-terminal α-helix, which penetrates the membrane to form a functional pore, appears to be optimal for the membrane thickness represented by di-18:1 PC.
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Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , 20500 Turku, Finland
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , 20500 Turku, Finland
| | | | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , 20500 Turku, Finland
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Biophysical and biochemical strategies to understand membrane binding and pore formation by sticholysins, pore-forming proteins from a sea anemone. Biophys Rev 2017; 9:529-544. [PMID: 28853034 DOI: 10.1007/s12551-017-0316-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/08/2017] [Indexed: 10/19/2022] Open
Abstract
Actinoporins constitute a unique class of pore-forming toxins found in sea anemones that are able to bind and oligomerize in membranes, leading to cell swelling, impairment of ionic gradients and, eventually, to cell death. In this review we summarize the knowledge generated from the combination of biochemical and biophysical approaches to the study of sticholysins I and II (Sts, StI/II), two actinoporins largely characterized by the Center of Protein Studies at the University of Havana during the last 20 years. These approaches include strategies for understanding the toxin structure-function relationship, the protein-membrane association process leading to pore formation and the interaction of toxin with cells. The rational combination of experimental and theoretical tools have allowed unraveling, at least partially, of the complex mechanisms involved in toxin-membrane interaction and of the molecular pathways triggered upon this interaction. The study of actinoporins is important not only to gain an understanding of their biological roles in anemone venom but also to investigate basic molecular mechanisms of protein insertion into membranes, protein-lipid interactions and the modulation of protein conformation by lipid binding. A deeper knowledge of the basic molecular mechanisms involved in Sts-cell interaction, as described in this review, will support the current investigations conducted by our group which focus on the design of immunotoxins against tumor cells and antigen-releasing systems to cell cytosol as Sts-based vaccine platforms.
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Laborde RJ, Sanchez-Ferras O, Luzardo MC, Cruz-Leal Y, Fernández A, Mesa C, Oliver L, Canet L, Abreu-Butin L, Nogueira CV, Tejuca M, Pazos F, Álvarez C, Alonso ME, Longo-Maugéri IM, Starnbach MN, Higgins DE, Fernández LE, Lanio ME. Novel Adjuvant Based on the Pore-Forming Protein Sticholysin II Encapsulated into Liposomes Effectively Enhances the Antigen-Specific CTL-Mediated Immune Response. THE JOURNAL OF IMMUNOLOGY 2017; 198:2772-2784. [PMID: 28258198 DOI: 10.4049/jimmunol.1600310] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 01/18/2017] [Indexed: 12/21/2022]
Abstract
Vaccine strategies to enhance CD8+ CTL responses remain a current challenge because they should overcome the plasmatic and endosomal membranes for favoring exogenous Ag access to the cytosol of APCs. As a way to avoid this hurdle, sticholysin (St) II, a pore-forming protein from the Caribbean Sea anemone Stichodactyla helianthus, was encapsulated with OVA into liposomes (Lp/OVA/StII) to assess their efficacy to induce a CTL response. OVA-specific CD8+ T cells transferred to mice immunized with Lp/OVA/StII experienced a greater expansion than when the recipients were injected with the vesicles without St, mostly exhibiting a memory phenotype. Consequently, Lp/OVA/StII induced a more potent effector function, as shown by CTLs, in vivo assays. Furthermore, treatment of E.G7-OVA tumor-bearing mice with Lp/OVA/StII significantly reduced tumor growth being more noticeable in the preventive assay. The contribution of CD4+ and CD8+ T cells to CTL and antitumor activity, respectively, was elucidated. Interestingly, the irreversibly inactive variant of the StI mutant StI W111C, encapsulated with OVA into Lp, elicited a similar OVA-specific CTL response to that observed with Lp/OVA/StII or vesicles encapsulating recombinant StI or the reversibly inactive StI W111C dimer. These findings suggest the relative independence between StII pore-forming activity and its immunomodulatory properties. In addition, StII-induced in vitro maturation of dendritic cells might be supporting these properties. These results are the first evidence, to our knowledge, that StII, a pore-forming protein from a marine eukaryotic organism, encapsulated into Lp functions as an adjuvant to induce a robust specific CTL response.
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Affiliation(s)
- Rady J Laborde
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Oraly Sanchez-Ferras
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - María C Luzardo
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Yoelys Cruz-Leal
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Audry Fernández
- Immunobiology Division, Center of Molecular Immunology, Havana 11600, Cuba
| | - Circe Mesa
- Immunobiology Division, Center of Molecular Immunology, Havana 11600, Cuba
| | - Liliana Oliver
- Immunobiology Division, Center of Molecular Immunology, Havana 11600, Cuba
| | - Liem Canet
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Liane Abreu-Butin
- Discipline of Immunology, Department of Microbiology, Immunology, and Parasitology, Paulista Medical School, Federal University of São Paulo, São Paulo 04023-900, Brazil; and
| | - Catarina V Nogueira
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Mayra Tejuca
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Fabiola Pazos
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Carlos Álvarez
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - María E Alonso
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba
| | - Ieda M Longo-Maugéri
- Discipline of Immunology, Department of Microbiology, Immunology, and Parasitology, Paulista Medical School, Federal University of São Paulo, São Paulo 04023-900, Brazil; and
| | - Michael N Starnbach
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Darren E Higgins
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Luis E Fernández
- Immunobiology Division, Center of Molecular Immunology, Havana 11600, Cuba;
| | - María E Lanio
- Center for Protein Studies, Faculty of Biology, University of Havana, Havana 10400, Cuba;
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26
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Mesa-Galloso H, Delgado-Magnero KH, Cabezas S, López-Castilla A, Hernández-González JE, Pedrera L, Alvarez C, Peter Tieleman D, García-Sáez AJ, Lanio ME, Ros U, Valiente PA. Disrupting a key hydrophobic pair in the oligomerization interface of the actinoporins impairs their pore-forming activity. Protein Sci 2017; 26:550-565. [PMID: 28000294 DOI: 10.1002/pro.3104] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 12/12/2016] [Accepted: 12/13/2016] [Indexed: 11/10/2022]
Abstract
Crystallographic data of the dimeric and octameric forms of fragaceatoxin C (FraC) suggested the key role of a small hydrophobic protein-protein interaction surface for actinoporins oligomerization and pore formation in membranes. However, site-directed mutagenesis studies supporting this hypothesis for others actinoporins are still lacking. Here, we demonstrate that disrupting the key hydrophobic interaction between V60 and F163 (FraC numbering scheme) in the oligomerization interface of FraC, equinatoxin II (EqtII), and sticholysin II (StII) impairs the pore formation activity of these proteins. Our results allow for the extension of the importance of FraC protein-protein interactions in the stabilization of the oligomeric intermediates of StII and EqtII pointing out that all of these proteins follow a similar pathway of membrane disruption. These findings support the hybrid pore proposal as the universal model of actinoporins pore formation. Moreover, we reinforce the relevance of dimer formation, which appears to be a functional intermediate in the assembly pathway of some different pore-forming proteins.
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Affiliation(s)
- Haydeé Mesa-Galloso
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
| | - Karelia H Delgado-Magnero
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.,Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N1N4, Canada
| | - Sheila Cabezas
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
| | - Aracelys López-Castilla
- Medical Biochemistry Institute, Federal University of Rio de Janeiro, Cidade Universitária, Ilha do Fundão Rio de Janeiro, CEP: 21.941-902, RJ, Brazil
| | - Jorge E Hernández-González
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
| | - Lohans Pedrera
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
| | - Carlos Alvarez
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
| | - D Peter Tieleman
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N1N4, Canada
| | - Ana J García-Sáez
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str.4, Tübingen, 72076, Germany
| | - Maria E Lanio
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
| | - Uris Ros
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.,Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str.4, Tübingen, 72076, Germany
| | - Pedro A Valiente
- Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba
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27
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Cabezas S, Ho S, Ros U, Lanio ME, Alvarez C, van der Goot FG. Damage of eukaryotic cells by the pore-forming toxin sticholysin II: Consequences of the potassium efflux. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:982-992. [PMID: 28173991 DOI: 10.1016/j.bbamem.2017.02.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/06/2017] [Accepted: 02/03/2017] [Indexed: 01/17/2023]
Abstract
Pore-forming toxins (PFTs) form holes in membranes causing one of the most catastrophic damages to a target cell. Target organisms have evolved a regulated response against PFTs damage including cell membrane repair. This ability of cells strongly depends on the toxin concentration and the properties of the pores. It has been hypothesized that there is an inverse correlation between the size of the pores and the time required to repair the membrane, which has been for long a non-intuitive concept and far to be completely understood. Moreover, there is a lack of information about how cells react to the injury triggered by eukaryotic PFTs. Here, we investigated some molecular events related with eukaryotic cells response against the membrane damage caused by sticholysin II (StII), a eukaryotic PFT produced by a sea anemone. We evaluated the change in the cytoplasmic potassium, identified the main MAPK pathways activated after pore-formation by StII, and compared its effect with those from two well-studied bacterial PFTs: aerolysin and listeriolysin O (LLO). Strikingly, we found that membrane recovery upon StII damage takes place in a time scale similar to LLO in spite of the fact that they form pores by far different in size. Furthermore, our data support a common role of the potassium ion, as well as MAPKs in the mechanism that cells use to cope with these toxins injury.
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Affiliation(s)
- Sheila Cabezas
- Center for Protein Studies, Faculty of Biology, Havana University, Street 25 # 455, CP 10400, Havana, Cuba.
| | - Sylvia Ho
- École Polytechnique Fédérale de Lausanne, Global Health Institution, Faculty of Life Sciences, Station 15, CH 1015 Lausanne, Switzerland.
| | - Uris Ros
- Center for Protein Studies, Faculty of Biology, Havana University, Street 25 # 455, CP 10400, Havana, Cuba; Interfakultäres Institut für Biochemie, Universität Tübingen, Hoppe Seyler Strasse, 4, 72076, Tübingen, Germany.
| | - María E Lanio
- Center for Protein Studies, Faculty of Biology, Havana University, Street 25 # 455, CP 10400, Havana, Cuba.
| | - Carlos Alvarez
- Center for Protein Studies, Faculty of Biology, Havana University, Street 25 # 455, CP 10400, Havana, Cuba.
| | - F Gisou van der Goot
- École Polytechnique Fédérale de Lausanne, Global Health Institution, Faculty of Life Sciences, Station 15, CH 1015 Lausanne, Switzerland.
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28
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García-Linares S, Rivera-de-Torre E, Palacios-Ortega J, Gavilanes JG, Martínez-del-Pozo Á. The Metamorphic Transformation of a Water-Soluble Monomeric Protein Into an Oligomeric Transmembrane Pore. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2017. [DOI: 10.1016/bs.abl.2017.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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29
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García-Linares S, Maula T, Rivera-de-Torre E, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á. Role of the Tryptophan Residues in the Specific Interaction of the Sea Anemone Stichodactyla helianthus's Actinoporin Sticholysin II with Biological Membranes. Biochemistry 2016; 55:6406-6420. [PMID: 27933775 DOI: 10.1021/acs.biochem.6b00935] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Actinoporins are pore-forming toxins from sea anemones. Upon interaction with sphingomyelin-containing bilayers, they become integral oligomeric membrane structures that form a pore. Sticholysin II from Stichodactyla helianthus contains five tryptophans located at strategic positions; its role has now been studied using different mutants. Results show that W43 and W115 play a determinant role in maintaining the high thermostability of the protein, while W146 provides specific interactions for protomer-protomer assembly. W110 and W114 sustain the hydrophobic effect, which is one of the major driving forces for membrane binding in the presence of Chol. However, in its absence, additional interactions with sphingomyelin are required. These conclusions were confirmed with two sphingomyelin analogues, one of which had impaired hydrogen bonding properties. The results obtained support actinoporins' Trp residues playing a major role in membrane recognition and binding, but their residues have an only minor influence on the diffusion and oligomerization steps needed to assemble a functional pore.
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Affiliation(s)
- Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid, Spain.,Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Turku, Finland
| | - Terhi Maula
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Turku, Finland
| | | | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Turku, Finland
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30
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Morante K, Bellomio A, Gil-Cartón D, Redondo-Morata L, Sot J, Scheuring S, Valle M, González-Mañas JM, Tsumoto K, Caaveiro JMM. Identification of a Membrane-bound Prepore Species Clarifies the Lytic Mechanism of Actinoporins. J Biol Chem 2016; 291:19210-19219. [PMID: 27445331 PMCID: PMC5016661 DOI: 10.1074/jbc.m116.734053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Indexed: 11/06/2022] Open
Abstract
Pore-forming toxins (PFTs) are cytolytic proteins belonging to the molecular warfare apparatus of living organisms. The assembly of the functional transmembrane pore requires several intermediate steps ranging from a water-soluble monomeric species to the multimeric ensemble inserted in the cell membrane. The non-lytic oligomeric intermediate known as prepore plays an essential role in the mechanism of insertion of the class of β-PFTs. However, in the class of α-PFTs, like the actinoporins produced by sea anemones, evidence of membrane-bound prepores is still lacking. We have employed single-particle cryo-electron microscopy (cryo-EM) and atomic force microscopy to identify, for the first time, a prepore species of the actinoporin fragaceatoxin C bound to lipid vesicles. The size of the prepore coincides with that of the functional pore, except for the transmembrane region, which is absent in the prepore. Biochemical assays indicated that, in the prepore species, the N terminus is not inserted in the bilayer but is exposed to the aqueous solution. Our study reveals the structure of the prepore in actinoporins and highlights the role of structural intermediates for the formation of cytolytic pores by an α-PFT.
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Affiliation(s)
- Koldo Morante
- From the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.,the Department of Biochemistry and Molecular Biology and.,Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, P. O. Box 644, 48080 Bilbao, Spain
| | - Augusto Bellomio
- the Department of Biochemistry and Molecular Biology and.,Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, P. O. Box 644, 48080 Bilbao, Spain
| | - David Gil-Cartón
- the Structural Biology Unit, Center for Cooperative Research in Biosciences, CICbiogune, 48160 Derio, Spain
| | - Lorena Redondo-Morata
- the U1006 INSERM, Aix-Marseille Université, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13009 Marseille, France, and
| | - Jesús Sot
- the Department of Biochemistry and Molecular Biology and.,Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, P. O. Box 644, 48080 Bilbao, Spain
| | - Simon Scheuring
- the U1006 INSERM, Aix-Marseille Université, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13009 Marseille, France, and
| | - Mikel Valle
- the Structural Biology Unit, Center for Cooperative Research in Biosciences, CICbiogune, 48160 Derio, Spain
| | | | - Kouhei Tsumoto
- From the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan, .,the Institute of Medical Science, University of Tokyo, Minato-ku, 108-8639 Tokyo, Japan
| | - Jose M M Caaveiro
- From the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan,
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31
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Abstract
This review covers the literature published in 2014 for marine natural products (MNPs), with 1116 citations (753 for the period January to December 2014) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1378 in 456 papers for 2014), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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32
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Cosentino K, Ros U, García-Sáez AJ. Assembling the puzzle: Oligomerization of α-pore forming proteins in membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:457-466. [PMID: 26375417 DOI: 10.1016/j.bbamem.2015.09.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/26/2015] [Accepted: 09/09/2015] [Indexed: 12/21/2022]
Abstract
Pore forming proteins (PFPs) share the ability of creating pores that allow the passage of ions, proteins or other constituents through a wide variety of target membranes, ranging from bacteria to humans. They often cause cell death, as pore formation disrupts the membrane permeability barrier required for maintaining cell homeostasis. The organization into supramolecular complexes or oligomers that pierce the membrane is a common feature of PFPs. However, the molecular pathway of self-assembly and pore opening remains unclear. Here, we review the most recent discoveries in the mechanism of membrane oligomerization and pore formation of a subset of PFPs, the α-PFPs, whose pore-forming domains are formed by helical segments. Only now we are starting to grasp the molecular details of their function, mainly thanks to the introduction of single molecule microscopy and nanoscopy techniques. This article is part of a Special Issue entitled: Pore-forming toxins edited by Mauro Dalla Serra and Franco Gambale.
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Affiliation(s)
- Katia Cosentino
- Interfaculty Institute of Biochemistry (IFIB), University of Tübingen, Tübingen, Germany.,Max-Planck Institute for Intelligent Systems, Stuttgart, Germany
| | - Uris Ros
- Interfaculty Institute of Biochemistry (IFIB), University of Tübingen, Tübingen, Germany.,Max-Planck Institute for Intelligent Systems, Stuttgart, Germany.,Center for Protein Studies, Havana University, Havana, Cuba
| | - Ana J García-Sáez
- Interfaculty Institute of Biochemistry (IFIB), University of Tübingen, Tübingen, Germany.,Max-Planck Institute for Intelligent Systems, Stuttgart, Germany
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33
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Rojko N, Dalla Serra M, Maček P, Anderluh G. Pore formation by actinoporins, cytolysins from sea anemones. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:446-56. [PMID: 26351738 DOI: 10.1016/j.bbamem.2015.09.007] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 11/30/2022]
Abstract
Actinoporins (APs) from sea anemones are ~20 kDa pore forming toxins with a β-sandwich structure flanked by two α-helices. The molecular mechanism of APs pore formation is composed of several well-defined steps. APs bind to membrane by interfacial binding site composed of several aromatic amino acid residues that allow binding to phosphatidylcholine and specific recognition of sphingomyelin. Subsequently, the N-terminal α-helix from the β-sandwich has to be inserted into the lipid/water interphase in order to form a functional pore. Functional studies and single molecule imaging revealed that only several monomers, 3-4, oligomerise to form a functional pore. In this model the α-helices and surrounding lipid molecules build toroidal pore. In agreement, AP pores are transient and electrically heterogeneous. On the contrary, crystallized oligomers of actinoporin fragaceatoxin C were found to be composed of eight monomers with no lipids present between the adjacent α-helices. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Maur Dalla Serra and Franco Gambale.
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Affiliation(s)
- Nejc Rojko
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia
| | - Mauro Dalla Serra
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche & Fondazione Bruno Kessler, via alla Cascata 56/C, 38123 Trento, Italy
| | - Peter Maček
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia; Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia.
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34
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The effect of cholesterol on the long-range network of interactions established among sea anemone Sticholysin II residues at the water-membrane interface. Mar Drugs 2015; 13:1647-65. [PMID: 25815890 PMCID: PMC4413179 DOI: 10.3390/md13041647] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/03/2015] [Accepted: 03/16/2015] [Indexed: 12/21/2022] Open
Abstract
Actinoporins are α-pore forming proteins with therapeutic potential, produced by sea anemones. Sticholysin II (StnII) from Stichodactyla helianthus is one of its most extensively characterized members. These proteins remain stably folded in water, but upon interaction with lipid bilayers, they oligomerize to form a pore. This event is triggered by the presence of sphingomyelin (SM), but cholesterol (Chol) facilitates pore formation. Membrane attachment and pore formation require changes involving long-distance rearrangements of residues located at the protein-membrane interface. The influence of Chol on membrane recognition, oligomerization, and/or pore formation is now studied using StnII variants, which are characterized in terms of their ability to interact with model membranes in the presence or absence of Chol. The results obtained frame Chol not only as an important partner for SM for functional membrane recognition but also as a molecule which significantly reduces the structural requirements for the mentioned conformational rearrangements to occur. However, given that the DOPC:SM:Chol vesicles employed display phase coexistence and have domain boundaries, the observed effects could be also due to the presence of these different phases on the membrane. In addition, it is also shown that the Arg51 guanidinium group is strictly required for membrane recognition, independently of the presence of Chol.
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35
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Subburaj Y, Ros U, Hermann E, Tong R, García-Sáez AJ. Toxicity of an α-pore-forming toxin depends on the assembly mechanism on the target membrane as revealed by single molecule imaging. J Biol Chem 2014; 290:4856-4865. [PMID: 25525270 DOI: 10.1074/jbc.m114.600676] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
α-Pore-forming toxins (α-PFTs) are ubiquitous defense tools that kill cells by opening pores in the target cell membrane. Despite their relevance in host/pathogen interactions, very little is known about the pore stoichiometry and assembly pathway leading to membrane permeabilization. Equinatoxin II (EqtII) is a model α-PFT from sea anemone that oligomerizes and forms pores in sphingomyelin-containing membranes. Here, we determined the spatiotemporal organization of EqtII in living cells by single molecule imaging. Surprisingly, we found that on the cell surface EqtII did not organize into a unique oligomeric form. Instead, it existed as a mixture of oligomeric species mostly including monomers, dimers, tetramers, and hexamers. Mathematical modeling based on our data supported a new model in which toxin clustering happened in seconds and proceeded via condensation of EqtII dimer units formed upon monomer association. Furthermore, altering the pathway of EqtII assembly strongly affected its toxic activity, which highlights the relevance of the assembly mechanism on toxicity.
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Affiliation(s)
- Yamunadevi Subburaj
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany; German Cancer Research Center, Bioquant, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Uris Ros
- Center for Protein Studies, Faculty of Biology, Calle 25 #455, Plaza de la Revolución, La Habana, Cuba
| | - Eduard Hermann
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany; German Cancer Research Center, Bioquant, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany,; Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| | - Rudi Tong
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany
| | - Ana J García-Sáez
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany; German Cancer Research Center, Bioquant, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany,; Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany.
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