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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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2
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Sea Anemones, Actinoporins, and Cholesterol. Int J Mol Sci 2022; 23:ijms23158771. [PMID: 35955905 PMCID: PMC9369217 DOI: 10.3390/ijms23158771] [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: 07/11/2022] [Revised: 08/01/2022] [Accepted: 08/05/2022] [Indexed: 11/17/2022] Open
Abstract
Spanish or Spanish-speaking scientists represent a remarkably populated group within the scientific community studying pore-forming proteins. Some of these scientists, ourselves included, focus on the study of actinoporins, a fascinating group of metamorphic pore-forming proteins produced within the venom of several sea anemones. These toxic proteins can spontaneously transit from a water-soluble fold to an integral membrane ensemble because they specifically recognize sphingomyelin in the membrane. Once they bind to the bilayer, they subsequently oligomerize into a pore that triggers cell-death by osmotic shock. In addition to sphingomyelin, some actinoporins are especially sensible to some other membrane components such as cholesterol. Our group from Universidad Complutense of Madrid has focused greatly on the role played by sterols in this water–membrane transition, a question which still remains only partially solved and constitutes the main core of the article below.
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García‐Linares S, Amigot‐Sánchez R, García‐Montoya C, Heras‐Márquez D, Alfonso C, Luque‐Ortega JR, Gavilanes JG, Martínez‐del‐Pozo Á, Palacios‐Ortega J. Sticholysin I‐II oligomerization in the absence of membranes. FEBS Lett 2022; 596:1029-1036. [DOI: 10.1002/1873-3468.14326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Sara García‐Linares
- Departamento de Bioquímica y Biología Molecular Universidad Complutense Madrid Spain
| | - Rafael Amigot‐Sánchez
- Departamento de Bioquímica y Biología Molecular Universidad Complutense Madrid Spain
| | - Carmen García‐Montoya
- Departamento de Bioquímica y Biología Molecular Universidad Complutense Madrid Spain
| | - Diego Heras‐Márquez
- Departamento de Bioquímica y Biología Molecular Universidad Complutense Madrid Spain
| | - Carlos Alfonso
- Systems Biochemistry of Bacterial Division Lab Centro de Investigaciones Biológicas Margarita Salas (CSIC) C. Ramiro de Maeztu 9 28040 Madrid Spain
| | - Juan Román Luque‐Ortega
- Molecular Interactions Facility Centro de Investigaciones Biológicas Margarita Salas (CSIC) C. Ramiro de Maeztu 9 28040 Madrid Spain
| | - José G. Gavilanes
- Departamento de Bioquímica y Biología Molecular Universidad Complutense Madrid Spain
| | | | - Juan Palacios‐Ortega
- Departamento de Bioquímica y Biología Molecular Universidad Complutense Madrid Spain
- Faculty of Science and Engineering Åbo Akademi University Turku Finland
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4
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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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5
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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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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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Lipid interactions of an actinoporin pore-forming oligomer. Biophys J 2021; 120:1357-1366. [PMID: 33617834 DOI: 10.1016/j.bpj.2021.02.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/16/2021] [Accepted: 02/11/2021] [Indexed: 12/16/2022] Open
Abstract
The actinoporins are cytolytic toxins produced by sea anemones. Upon encountering a membrane, preferably containing sphingomyelin, they oligomerize and insert their N-terminal helix into the membrane, forming a pore. Whether sphingomyelin is specifically recognized by the protein or simply induces phase coexistence in the membrane has been debated. Here, we perform multi-microsecond molecular dynamics simulations of an octamer of fragaceatoxin C, a member of the actinoporin family, in lipid bilayers containing either pure 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or a 1:1 mixture of DOPC and palmitoyl sphingomyelin (PSM). The complex is highly stable in both environments, with only slight fraying of the inserted helices near their N-termini. Analyzing the structural parameters of the mixed membrane in the course of the simulation, we see signs of a phase transition for PSM in the inner leaflet of the bilayer. In both leaflets, cross-interactions between lipids of different type decrease over time. Surprisingly, the aromatic loop thought to be responsible for sphingomyelin recognition interacts more with DOPC than PSM by the end of the simulation. These results support the notion that the key membrane property that actinoporins recognize is lipid phase coexistence.
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8
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Palacios-Ortega J, Rivera-de-Torre E, García-Linares S, Gavilanes JG, Martínez-Del-Pozo Á, Slotte JP. Oligomerization of Sticholysins from Förster Resonance Energy Transfer. Biochemistry 2021; 60:314-323. [PMID: 33445865 PMCID: PMC8023573 DOI: 10.1021/acs.biochem.0c00840] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
![]()
Sticholysins
are pore-forming toxins produced by sea anemones that
are members of the actinoporin family. They exert their activity by
forming pores on membranes, provided they have sphingomyelin. To assemble
into pores, specific recognition, binding, and oligomerization are
required. While recognition and binding have been extensively studied,
delving into the oligomerization process and the stoichiometry of
the pores has been more difficult. Here, we present evidence that
these toxins are capable of oligomerizing in solution and suggesting
that the interaction of sticholysin II (StnII) with its isoform sticholysin
I (StnI) is stronger than that of StnI with itself. We also show that
the stoichiometry of the final, thermodynamically stable StnI pores
is, at least, heptameric. Furthermore, our results indicate that this
association maintains its oligomerization number when StnII is included,
indicating that the stoichiometry of StnII is also of that order,
and not tetrameric, as previously thought. These results are compatible
with the stoichiometry observed for the crystallized pore of FraC,
another very similar actinoporin produced by a different sea anemone
species. Our results also indicate that the stoichiometry of actinoporin
pores in equilibrium is conserved regardless of the particular composition
of a given pore ensemble, which we have shown for mixed sticholysin
pores.
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Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, 28040 Madrid, Spain.,Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
| | | | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, 28040 Madrid, Spain
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, 28040 Madrid, Spain
| | | | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland
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Palacios-Ortega J, Rivera-de-Torre E, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á, García-Linares S. Biophysical approaches to study actinoporin-lipid interactions. Methods Enzymol 2021; 649:307-339. [PMID: 33712191 DOI: 10.1016/bs.mie.2020.12.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein-lipid interactions are crucial events from a biochemical point of view, like the interaction of proteins with the cell plasma membrane, and their study is of great importance. Actinoporins are a very powerful tool to study this kind of interactions, since they are soluble proteins in an aqueous environment, capable of inserting into membranes when they have the adequate composition. In fact, actinoporins have been used to study protein-lipid interactions for many years now. Sometimes it is not possible to use real biological membranes in the experiments, so model membranes need to be used. This article aims to give a thorough description of many of the techniques used to study actinoporin-lipid interactions, using both biological and model membranes: Hemolysis, release of vesicles content, surface plasmon resonance, isothermal titration calorimetry, fluorescence-based measurements, etc. Some of these techniques measure the actinoporins activity and some measure their binding properties. The combination of all the techniques described can offer valuable information about the thermodynamics and the kinetics of the actinoporin-lipid interaction.
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Affiliation(s)
- Juan Palacios-Ortega
- Department of Biochemistry and Molecular Biology, Complutense University, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Esperanza Rivera-de-Torre
- Department of Biochemistry and Molecular Biology, Complutense University, Madrid, Spain; Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - José G Gavilanes
- Department of Biochemistry and Molecular Biology, Complutense University, Madrid, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | | | - Sara García-Linares
- Department of Biochemistry and Molecular Biology, Complutense University, Madrid, Spain.
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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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11
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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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12
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Rivera-de-Torre E, Palacios-Ortega J, Garb JE, Slotte JP, Gavilanes JG, Martínez-Del-Pozo Á. Structural and functional characterization of sticholysin III: A newly discovered actinoporin within the venom of the sea anemone Stichodactyla helianthus. Arch Biochem Biophys 2020; 689:108435. [PMID: 32485153 DOI: 10.1016/j.abb.2020.108435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/23/2020] [Accepted: 05/25/2020] [Indexed: 01/19/2023]
Abstract
Actinoporins are a family of pore-forming toxins produced by sea anemones as part of their venomous cocktail. These proteins remain soluble and stably folded in aqueous solution, but when interacting with sphingomyelin-containing lipid membranes, they become integral oligomeric membrane structures that form a pore permeable to cations, which leads to cell death by osmotic shock. Actinoporins appear as multigenic families within the genome of sea anemones: several genes encoding very similar actinoporins are detected within the same species. The Caribbean Sea anemone Stichodactyla helianthus produces three actinoporins (sticholysins I, II and III; StnI, StnII and StnIII) that differ in their toxic potency. For example, StnII is about four-fold more effective than StnI against sheep erythrocytes in causing hemolysis, and both show synergy. However, StnIII, recently discovered in the S. helianthus transcriptome, has not been characterized so far. Here we describe StnIII's spectroscopic and functional properties and show its potential to interact with the other Stns. StnIII seems to maintain the well-preserved fold of all actinoporins, characterized by a high content of β-sheet, but it is significantly less thermostable. Its functional characterization shows that the critical concentration needed to form active pores is higher than for either StnI or StnII, suggesting differences in behavior when oligomerizing on membrane surfaces. Our results show that StnIII is an interesting and unexpected piece in the puzzle of how this Caribbean Sea anemone species modulates its venomous activity.
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Affiliation(s)
- Esperanza Rivera-de-Torre
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland; Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Jessica E Garb
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain.
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13
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Partida-Hanon A, Maestro-López M, Vitale S, Turrà D, Di Pietro A, Martínez-Del-Pozo Á, Bruix M. Structure of Fungal α Mating Pheromone in Membrane Mimetics Suggests a Possible Role for Regulation at the Water-Membrane Interface. Front Microbiol 2020; 11:1090. [PMID: 32582073 PMCID: PMC7289986 DOI: 10.3389/fmicb.2020.01090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 04/30/2020] [Indexed: 12/14/2022] Open
Abstract
Fusarium oxysporum is a highly destructive plant pathogen and an emerging pathogen of humans. Like other ascomycete fungi, F. oxysporum secretes α-pheromone, a small peptide that functions both as a chemoattractant and as a quorum-sensing signal. Three of the ten amino acid residues of α-pheromone are tryptophan, an amino acid whose sidechain has high affinity for lipid bilayers, suggesting a possible interaction with biological membranes. Here we tested the effect of different lipid environments on α-pheromone structure and function. Using spectroscopic and calorimetric approaches, we show that this peptide interacts with negatively charged model phospholipid vesicles. Fluorescence emission spectroscopy and nuclear magnetic resonance (NMR) measurements revealed a key role of the positively charged groups and Trp residues. Furthermore, NMR-based calculation of the 3D structure in the presence of micelles, formed by lipid surfactants, suggests that α-pheromone can establish an intramolecular disulfide bond between the two cysteine residues during interaction with membranes, but not in the absence of lipid mimetics. Remarkably, this oxidized version of α-pheromone lacks biological activity as a chemoattractant and quorum-sensing molecule. These results suggest the presence of a previously unidentified redox regulated control of α-pheromone activity at the surface of the plasma membrane that could influence the interaction with its cognate G-protein coupled receptor.
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Affiliation(s)
- Angélica Partida-Hanon
- Department of Biological Physical Chemistry, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
| | - Moisés Maestro-López
- Department of Biochemistry and Molecular Biology, Faculty of Chemistry, Complutense University, Madrid, Spain
| | - Stefania Vitale
- Departmento de Genética, Universidad de Córdoba and Campus de Excelencia Agroalimentario (ceiA3), Córdoba, Spain
| | - David Turrà
- Departmento de Genética, Universidad de Córdoba and Campus de Excelencia Agroalimentario (ceiA3), Córdoba, Spain
| | - Antonio Di Pietro
- Departmento de Genética, Universidad de Córdoba and Campus de Excelencia Agroalimentario (ceiA3), Córdoba, Spain
| | - Álvaro Martínez-Del-Pozo
- Department of Biochemistry and Molecular Biology, Faculty of Chemistry, Complutense University, Madrid, Spain
| | - Marta Bruix
- Department of Biological Physical Chemistry, Institute of Physical Chemistry Rocasolano, CSIC, Madrid, Spain
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14
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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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15
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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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16
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Morante K, Bellomio A, Viguera AR, González-Mañas JM, Tsumoto K, Caaveiro JMM. The Isolation of New Pore-Forming Toxins from the Sea Anemone Actinia fragacea Provides Insights into the Mechanisms of Actinoporin Evolution. Toxins (Basel) 2019; 11:toxins11070401. [PMID: 31295915 PMCID: PMC6669745 DOI: 10.3390/toxins11070401] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/29/2019] [Accepted: 07/05/2019] [Indexed: 01/23/2023] Open
Abstract
Random mutations and selective pressure drive protein adaptation to the changing demands of the environment. As a consequence, nature favors the evolution of protein diversity. A group of proteins subject to exceptional environmental stress and known for their widespread diversity are the pore-forming hemolytic proteins from sea anemones, known as actinoporins. In this study, we identified and isolated new isoforms of actinoporins from the sea anemone Actinia fragacea (fragaceatoxins). We characterized their hemolytic activity, examined their stability and structure, and performed a comparative analysis of their primary sequence. Sequence alignment reveals that most of the variability among actinoporins is associated with non-functional residues. The differences in the thermal behavior among fragaceatoxins suggest that these variability sites contribute to changes in protein stability. In addition, the protein-protein interaction region showed a very high degree of identity (92%) within fragaceatoxins, but only 25% among all actinoporins examined, suggesting some degree of specificity at the species level. Our findings support the mechanism of evolutionary adaptation in actinoporins and reflect common pathways conducive to protein variability.
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Affiliation(s)
- Koldo Morante
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa (Bizkaia), Spain
| | - Augusto Bellomio
- Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa (Bizkaia), Spain
- Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) e Instituto de Química Biológica "Dr. Bernabé Bloj," Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000 San Miguel de Tucumán, Argentina
| | - Ana Rosa Viguera
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa (Bizkaia), Spain
| | - Juan Manuel González-Mañas
- Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain
| | - Kouhei Tsumoto
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
- Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan.
| | - Jose M M Caaveiro
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
- Department of Global Healthcare, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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17
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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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18
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Madio B, King GF, Undheim EAB. Sea Anemone Toxins: A Structural Overview. Mar Drugs 2019; 17:E325. [PMID: 31159357 PMCID: PMC6627431 DOI: 10.3390/md17060325] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/22/2019] [Accepted: 05/25/2019] [Indexed: 02/06/2023] Open
Abstract
Sea anemones produce venoms of exceptional molecular diversity, with at least 17 different molecular scaffolds reported to date. These venom components have traditionally been classified according to pharmacological activity and amino acid sequence. However, this classification system suffers from vulnerabilities due to functional convergence and functional promiscuity. Furthermore, for most known sea anemone toxins, the exact receptors they target are either unknown, or at best incomplete. In this review, we first provide an overview of the sea anemone venom system and then focus on the venom components. We have organised the venom components by distinguishing firstly between proteins and non-proteinaceous compounds, secondly between enzymes and other proteins without enzymatic activity, then according to the structural scaffold, and finally according to molecular target.
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Affiliation(s)
- Bruno Madio
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Eivind A B Undheim
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, QLD 4072, Australia.
- Centre for Ecology and Evolutionary Synthesis, Department of Biosciences, University of Oslo, 0316 Oslo, Norway.
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19
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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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20
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Ros U, Carretero GPB, Paulino J, Crusca E, Pazos F, Cilli EM, Lanio ME, Schreier S, Alvarez C. Self-association and folding in membrane determine the mode of action of peptides from the lytic segment of sticholysins. Biochimie 2018; 156:109-117. [PMID: 30326255 DOI: 10.1016/j.biochi.2018.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 10/11/2018] [Indexed: 01/09/2023]
Abstract
Sticholysin I and II (Sts: St I and St II) are proteins of biomedical interest that form pores upon the insertion of their N-terminus in the plasma membrane. Peptides spanning the N-terminal residues of StI (StI1-31) or StII (StII1-30) can mimic the permeabilizing ability of these toxins, emerging as candidates to rationalize their potential biomedical applications. These peptides have different activities that correlate with their hydrophobicity. However, it is not clear how this property contributes to peptide folding in solution or upon binding to membranes. Here we compared the conformational properties of these peptides and shorter versions lacking the hydrophobic segment 1-11 of StI (StI12-31) or 1-10 of StII (StII11-30). Folding of peptides was assessed in solution and in membrane mimetic systems and related with their ability to bind to membranes and to permeabilize lipid vesicles. Our results suggest that the differences in activity among peptides could be ascribed to their different folding propensity and different membrane binding properties. In solution, StII1-30 tends to acquire α-helical conformation coexisting with self-associated structures, while StI1-31 remains structureless. Both peptides fold as α-helix in membrane; but StII1-30 also self-associates in the lipid environment, a process that is favored by its higher affinity for membrane. We stress the contribution of the non-polar/polar balance of the 1-10 amino acid sequence of the peptides as a determining factor for different self-association capabilities. Such difference in hydrophobicity seems to determine the molecular path of peptides folding upon binding to membranes, with an impact in their permeabilizing activity. This study contributes to a better understanding of the molecular mechanisms underlying the permeabilizing activity of Sts N-terminal derived peptides, with connotation for the exploitation of these small molecules as alternative of the full-length toxins in clinical settings.
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Affiliation(s)
- Uris Ros
- Center for Protein Studies, Biology Faculty, University of Havana, Havana, Cuba
| | - Gustavo P B Carretero
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Joana Paulino
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Edson Crusca
- Department of Biochemistry, Institute of Chemistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Fabiola Pazos
- Center for Protein Studies, Biology Faculty, University of Havana, Havana, Cuba
| | - Eduardo M Cilli
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Maria E Lanio
- Center for Protein Studies, Biology Faculty, University of Havana, Havana, Cuba
| | - Shirley Schreier
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Carlos Alvarez
- Center for Protein Studies, Biology Faculty, University of Havana, Havana, Cuba.
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21
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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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22
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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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23
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Rivera-de-Torre E, Martínez-Del-Pozo Á, Garb JE. Stichodactyla helianthus' de novo transcriptome assembly: Discovery of a new actinoporin isoform. Toxicon 2018; 150:105-114. [PMID: 29787779 DOI: 10.1016/j.toxicon.2018.05.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 01/29/2023]
Abstract
Transcriptomic profiling of venom producing tissues from different animals is an effective approach for discovering new toxins useful in biotechnological and pharmaceutical applications, as well in evolutionary comparative studies of venomous animals. Stichodactyla helianthus is a Caribbean sea anemone which produces actinoporins as part of its toxic venom. This family of pore forming toxins is multigenic and at least two different isoforms, encoded by separate genes, are produced by S. helianthus. These isoforms, sticholysins I and II, share 93% amino acid identity but differ in their pore forming activity and act synergistically. This observation suggests that other actinoporin isoforms, if present in the venomous mixture, could offer an advantageous strategy to modulate whole venom activity. Using high-throughput sequencing we generated a de novo transcriptome of S. helianthus and determined the relative expression of assembled transcripts using RNA-Seq to better characterize components of this species' venom, focusing on actinoporin diversity. Applying this approach, we have discovered at least one new actinoporin variant from S. helianthus in addition to several other putative venom components.
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Affiliation(s)
- Esperanza Rivera-de-Torre
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA; Departamento de Bioquímica y Biología Molecular, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular, Facultad de CC. Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Jessica E Garb
- Department of Biological Sciences, University of Massachusetts Lowell, Lowell, MA, USA
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24
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Rivera-de-Torre E, Palacios-Ortega J, García-Linares S, Gavilanes JG, Martínez-Del-Pozo Á. One single salt bridge explains the different cytolytic activities shown by actinoporins sticholysin I and II from the venom of Stichodactyla helianthus. Arch Biochem Biophys 2017; 636:79-89. [PMID: 29138096 DOI: 10.1016/j.abb.2017.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/06/2017] [Accepted: 11/10/2017] [Indexed: 10/18/2022]
Abstract
Sticholysins I and II (StnI and StnII), α-pore forming toxins from the sea anemone Stichodactyla helianthus, are water-soluble toxic proteins which upon interaction with lipid membranes of specific composition bind to the bilayer, extend and insert their N-terminal α-helix, and become oligomeric integral membrane structures. The result is a pore that leads to cell death by osmotic shock. StnI and StnII show 93% of sequence identity, but also different membrane pore-forming activities. The hydrophobicity profile along the first 18 residues revealed differences which were canceled by substituting StnI amino acids 2 and 9. Accordingly, the StnID9A mutant, and the corresponding StnIE2AD9A variant, showed enhanced hemolytic activity. They also revealed a key role for an exposed salt bridge between Asp9 and Lys68. This interaction is not possible in StnII but appears conserved in the other two well-characterized actinoporins, equinatoxin II and fragaceatoxin C. The StnII mutant A8D showed that this single replacement was enough to transform StnII into a version with impaired pore-forming activity. Overall, the results show the key importance of this salt bridge linking the N-terminal stretch to the β-sandwich core. A conclusion of general application for the understanding of salt bridges role in protein design, folding and stability.
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Affiliation(s)
- Esperanza Rivera-de-Torre
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain
| | - Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain.
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain.
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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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Soto C, del Valle A, Valiente PA, Ros U, Lanio ME, Hernández AM, Alvarez C. Differential binding and activity of the pore-forming toxin sticholysin II in model membranes containing diverse ceramide-derived lipids. Biochimie 2017; 138:20-31. [DOI: 10.1016/j.biochi.2017.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 04/04/2017] [Indexed: 01/07/2023]
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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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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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Evolution of the Cytolytic Pore-Forming Proteins (Actinoporins) in Sea Anemones. Toxins (Basel) 2016; 8:toxins8120368. [PMID: 27941639 PMCID: PMC5198562 DOI: 10.3390/toxins8120368] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/28/2016] [Accepted: 11/23/2016] [Indexed: 12/27/2022] Open
Abstract
Sea anemones (Cnidaria, Anthozoa, and Actiniaria) use toxic peptides to incapacitate and immobilize prey and to deter potential predators. Their toxin arsenal is complex, targeting a variety of functionally important protein complexes and macromolecules involved in cellular homeostasis. Among these, actinoporins are one of the better characterized toxins; these venom proteins form a pore in cellular membranes containing sphingomyelin. We used a combined bioinformatic and phylogenetic approach to investigate how actinoporins have evolved across three superfamilies of sea anemones (Actinioidea, Metridioidea, and Actinostoloidea). Our analysis identified 90 candidate actinoporins across 20 species. We also found clusters of six actinoporin-like genes in five species of sea anemone (Nematostella vectensis, Stomphia coccinea, Epiactis japonica, Heteractis crispa, and Diadumene leucolena); these actinoporin-like sequences resembled actinoporins but have a higher sequence similarity with toxins from fungi, cone snails, and Hydra. Comparative analysis of the candidate actinoporins highlighted variable and conserved regions within actinoporins that may pertain to functional variation. Although multiple residues are involved in initiating sphingomyelin recognition and membrane binding, there is a high rate of replacement for a specific tryptophan with leucine (W112L) and other hydrophobic residues. Residues thought to be involved with oligomerization were variable, while those forming the phosphocholine (POC) binding site and the N-terminal region involved with cell membrane penetration were highly conserved.
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García-Linares S, Rivera-de-Torre E, Morante K, Tsumoto K, Caaveiro JMM, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á. Differential Effect of Membrane Composition on the Pore-Forming Ability of Four Different Sea Anemone Actinoporins. Biochemistry 2016; 55:6630-6641. [PMID: 27933793 DOI: 10.1021/acs.biochem.6b01007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sea anemone actinoporins constitute a protein family of multigene pore-forming toxins (PFT). Equinatoxin II (EqtII), fragaceatoxin C (FraC), and sticholysins I and II (StnI and StnII, respectively), produced by three different sea anemone species, are the only actinoporins whose molecular structures have been studied in depth. These four proteins show high sequence identities and practically coincident three-dimensional structures. However, their pore-forming activity can be quite different depending on the model lipid system employed, a feature that has not been systematically studied before. Therefore, the aim of this work was to evaluate and compare the influence of several distinct membrane conditions on their particular pore-forming behavior. Using a complex model membrane system, such as sheep erythrocytes, StnII showed hemolytic activity much higher than those of the other three actinoporins studied. In lipid model systems, pore-forming ability when assayed against 4:1 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/sphingomyelin (SM) vesicles, with the membrane binding being the rate-limiting step, decreased in the following order: StnI > StnII > EqtII > FraC. When using 1:1:1 DOPC/SM/cholesterol LUVs, the presence of Chol not only enhanced membrane binding affinities by ∼2 orders of magnitude but also revealed how StnII was much faster than the other three actinoporins in producing calcein release. This ability agrees with the proposal that explains this behavior in terms of their high sequence variability along their first 30 N-terminal residues. The influence of interfacial hydrogen bonding in SM- or dihydro-SM-containing bilayers was also shown to be a generalized feature of the four actinoporins studied. It is finally hypothesized that this observed variable ability could be explained as a consequence of their distinct specificities and/or membrane binding affinities. Eventually, this behavior can be modulated by the nature of their natural target membranes or the interaction with not yet characterized isotoxin forms from the same sea anemone species.
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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
| | | | - Koldo Morante
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kouhei Tsumoto
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Jose M M Caaveiro
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - 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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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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García-Linares S, Palacios-Ortega J, Yasuda T, Åstrand M, Gavilanes JG, Martínez-del-Pozo Á, Slotte JP. Toxin-induced pore formation is hindered by intermolecular hydrogen bonding in sphingomyelin bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1189-95. [DOI: 10.1016/j.bbamem.2016.03.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/23/2016] [Accepted: 03/10/2016] [Indexed: 10/25/2022]
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Rivera-de-Torre E, García-Linares S, Alegre-Cebollada J, Lacadena J, Gavilanes JG, Martínez-Del-Pozo Á. Synergistic Action of Actinoporin Isoforms from the Same Sea Anemone Species Assembled into Functionally Active Heteropores. J Biol Chem 2016; 291:14109-14119. [PMID: 27129251 DOI: 10.1074/jbc.m115.710491] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/06/2022] Open
Abstract
Among the toxic polypeptides secreted in the venom of sea anemones, actinoporins are the pore-forming toxins whose toxic activity relies on the formation of oligomeric pores within biological membranes. Intriguingly, actinoporins appear as multigene families that give rise to many protein isoforms in the same individual displaying high sequence identities but large functional differences. However, the evolutionary advantage of producing such similar isotoxins is not fully understood. Here, using sticholysins I and II (StnI and StnII) from the sea anemone Stichodactyla helianthus, it is shown that actinoporin isoforms can potentiate each other's activity. Through hemolysis and calcein releasing assays, it is revealed that mixtures of StnI and StnII are more lytic than equivalent preparations of the corresponding isolated isoforms. It is then proposed that this synergy is due to the assembly of heteropores because (i) StnI and StnII can be chemically cross-linked at the membrane and (ii) the affinity of sticholysin mixtures for the membrane is increased with respect to any of them acting in isolation, as revealed by isothermal titration calorimetry experiments. These results help us understand the multigene nature of actinoporins and may be extended to other families of toxins that require oligomerization to exert toxicity.
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Affiliation(s)
- Esperanza Rivera-de-Torre
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid
| | | | - Javier Lacadena
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid.
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid.
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Weber DK, Yao S, Rojko N, Anderluh G, Lybrand TP, Downton MT, Wagner J, Separovic F. Characterization of the Lipid-Binding Site of Equinatoxin II by NMR and Molecular Dynamics Simulation. Biophys J 2016; 108:1987-96. [PMID: 25902438 DOI: 10.1016/j.bpj.2015.03.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/09/2015] [Accepted: 03/12/2015] [Indexed: 12/26/2022] Open
Abstract
Equinatoxin II (EqtII) is a soluble, 20 kDa pore-forming protein toxin isolated from the sea anemone Actinia equina. Although pore formation has long been known to occur in distinct stages, including monomeric attachment to phospholipid membranes followed by detachment of the N-terminal helical domain and oligomerization into the final pore assembly, atomistic-level detail of the protein-lipid interactions underlying these events remains elusive. Using high-resolution solution state NMR of uniformly-(15)N-labeled EqtII at the critical micelle concentration of dodecylphosphocholine, we have mapped the lipid-binding site through chemical shift perturbations. Subsequent docking of an EqtII monomer onto a dodecylphosphocholine micelle, followed by 400 ns of all-atom molecular dynamics simulation, saw several high-occupancy lipid-binding pockets stabilized by cation-π, hydrogen bonding, and hydrophobic interactions; and stabilization of the loop housing the conserved arginine-glycine-aspartate motif. Additional simulation of EqtII with an N-acetyl sphingomyelin micelle, for which high-resolution NMR data cannot be obtained due to aggregate formation, revealed that sphingomyelin specificity might occur via hydrogen bonding to the 3-OH and 2-NH groups unique to the ceramide backbone by side chains of D109 and Y113; and main chains of P81 and W112. Furthermore, a binding pocket formed by K30, K77, and P81, proximate to the hinge region of the N-terminal helix, was identified and may be implicated in triggering pore formation.
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Affiliation(s)
- Daniel K Weber
- School of Chemistry, University of Melbourne, Victoria, Australia; Bio21 Institute, University of Melbourne, Victoria, Australia
| | - Shenggen Yao
- Bio21 Institute, University of Melbourne, Victoria, Australia
| | - Nejc Rojko
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Terry P Lybrand
- Center for Structural Biology, Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Matthew T Downton
- IBM Research Collaboratory for Life Sciences, Victorian Life Sciences Computation Initiative, University of Melbourne, Victoria, Australia
| | - John Wagner
- IBM Research Collaboratory for Life Sciences, Victorian Life Sciences Computation Initiative, University of Melbourne, Victoria, Australia
| | - Frances Separovic
- School of Chemistry, University of Melbourne, Victoria, Australia; Bio21 Institute, University of Melbourne, Victoria, Australia.
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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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Valle A, Alvarado-Mesén J, Lanio M, Álvarez C, Barbosa J, Pazos I. The multigene families of actinoporins (part I): Isoforms and genetic structure. Toxicon 2015; 103:176-87. [DOI: 10.1016/j.toxicon.2015.06.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 05/31/2015] [Accepted: 06/23/2015] [Indexed: 11/24/2022]
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Ros U, Rodríguez-Vera W, Pedrera L, Valiente PA, Cabezas S, Lanio ME, García-Sáez AJ, Alvarez C. Differences in activity of actinoporins are related with the hydrophobicity of their N-terminus. Biochimie 2015; 116:70-8. [DOI: 10.1016/j.biochi.2015.06.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 06/25/2015] [Indexed: 10/23/2022]
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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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Mutagenesis and functional analysis of the pore-forming toxin HALT-1 from Hydra magnipapillata. Toxins (Basel) 2015; 7:407-22. [PMID: 25654788 PMCID: PMC4344632 DOI: 10.3390/toxins7020407] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 01/27/2015] [Indexed: 12/02/2022] Open
Abstract
Actinoporins are small 18.5 kDa pore-forming toxins. A family of six actinoporin genes has been identified in the genome of Hydra magnipapillata, and HALT-1 (Hydra actinoporin-like toxin-1) has been shown to have haemolytic activity. In this study, we have used site-directed mutagenesis to investigate the role of amino acids in the pore-forming N-terminal region and the conserved aromatic cluster required for cell membrane binding. A total of 10 mutants of HALT-1 were constructed and tested for their haemolytic and cytolytic activity on human erythrocytes and HeLa cells, respectively. Insertion of 1–4 negatively charged residues in the N-terminal region of HALT-1 strongly reduced haemolytic and cytolytic activity, suggesting that the length or charge of the N-terminal region is critical for pore-forming activity. Moreover, substitution of amino acids in the conserved aromatic cluster reduced haemolytic and cytolytic activity by more than 80%, suggesting that these aromatic amino acids are important for attachment to the lipid membrane as shown for other actinoporins. The results suggest that HALT-1 and other actinoporins share similar mechanisms of pore formation and that it is critical for HALT-1 to maintain an amphipathic helix at the N-terminus and an aromatic amino acid-rich segment at the site of membrane binding.
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Fauth EVF, Cilli EM, Ligabue-Braun R, Verli H. Differential effect of solution conditions on the conformation of the actinoporins Sticholysin II and Equinatoxin II. AN ACAD BRAS CIENC 2015; 86:1949-62. [PMID: 25590731 DOI: 10.1590/0001-3765201420140270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/11/2014] [Indexed: 11/22/2022] Open
Abstract
Actinoporins are a family of pore-forming proteins with hemolytic activity. The structural basis for such activity appears to depend on their correct folding. Such folding encompasses a phosphocholine binding site, a tryptophan-rich region and the activity-related N-terminus segment. Additionally, different solution conditions are known to be able to influence the pore formation by actinoporins, as for Sticholysin II (StnII) and Equinatoxin II (EqtxII). In this context, the current work intends to characterize the influence of distinct solution conditions in the conformational behavior of these proteins through molecular dynamics (MD) simulations. The obtained data offer structural insights into actinoporins dynamics in solution, characterizing its conformational behavior at the atomic level, in accordance with previous experimental data on StnII and EqtxII hemolytic activities.
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Affiliation(s)
| | - Eduardo M Cilli
- Departamento de Bioquímica e Tecnologia Química, UNESP, Instituto de Química, Universidade Estadual Paulista, Araraquara, SP, Brasil
| | | | - Hugo Verli
- Centro de Biotecnologia, UFRGS, Porto Alegre, RS, Brasil
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Antonini V, Pérez-Barzaga V, Bampi S, Pentón D, Martínez D, Serra MD, Tejuca M. Functional characterization of sticholysin I and W111C mutant reveals the sequence of the actinoporin's pore assembly. PLoS One 2014; 9:e110824. [PMID: 25350457 PMCID: PMC4211696 DOI: 10.1371/journal.pone.0110824] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/19/2014] [Indexed: 12/20/2022] Open
Abstract
The use of pore-forming toxins in the construction of immunotoxins against tumour cells is an alternative for cancer therapy. In this protein family one of the most potent toxins are the actinoporins, cytolysins from sea anemones. We work on the construction of tumour proteinase-activated immunotoxins using sticholysin I (StI), an actinoporin isolated from the sea anemone Stichodactyla helianthus. To accomplish this objective, recombinant StI (StIr) with a mutation in the membrane binding region has been employed. In this work, it was evaluated the impact of mutating tryptophan 111 to cysteine on the toxin pore forming capability. StI W111C is still able to permeabilize erythrocytes and liposomes, but at ten-fold higher concentration than StI. This is due to its lower affinity for the membrane, which corroborates the importance of residue 111 for the binding of actinoporins to the lipid bilayer. In agreement, other functional characteristics not directly associated to the binding, are essentially the same for both variants, that is, pores have oligomeric structures with similar radii, conductance, cation-selectivity, and instantaneous current-voltage behavior. In addition, this work provides experimental evidence sustaining the toroidal protein-lipid actinoporins lytic structures, since the toxins provoke the trans-bilayer movement (flip-flop) of a pyrene-labeled analogue of phosphatidylcholine in liposomes, indicating the existence of continuity between the outer and the inner membrane leaflet. Finally, our planar lipid membranes results have also contributed to a better understanding of the actinoporin's pore assembly mechanism. After the toxin binding and the N-terminal insertion in the lipid membrane, the pore assembly occurs by passing through different transient sub-conductance states. These states, usually 3 or 4, are due to the successive incorporation of N-terminal α-helices and lipid heads to the growing pores until a stable toroidal oligomeric structure is formed, which is mainly tetrameric.
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Affiliation(s)
- Valeria Antonini
- National Research Council of Italy - Institute of Biophysics and Bruno Kessler Foundation, Trento, Italy
| | - Victor Pérez-Barzaga
- Center for Protein Studies, Faculty of Biology, University of Havana, Vedado, Ciudad de La Habana, Cuba
| | - Silvia Bampi
- National Research Council of Italy - Institute of Biophysics and Bruno Kessler Foundation, Trento, Italy
| | - David Pentón
- Center for Protein Studies, Faculty of Biology, University of Havana, Vedado, Ciudad de La Habana, Cuba
| | - Diana Martínez
- Center for Protein Studies, Faculty of Biology, University of Havana, Vedado, Ciudad de La Habana, Cuba
| | - Mauro Dalla Serra
- National Research Council of Italy - Institute of Biophysics and Bruno Kessler Foundation, Trento, Italy
- * E-mail: (MDS); (MT)
| | - Mayra Tejuca
- Center for Protein Studies, Faculty of Biology, University of Havana, Vedado, Ciudad de La Habana, Cuba
- * E-mail: (MDS); (MT)
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León L, Lissi EA, Celedón G, Gonzalez G, Pazos F, Alvarez C, Lanio ME. Inactivation of the pore-forming toxin Sticholysin I by peroxynitrite: protection by cys groups incorporated in the toxin. Protein J 2014; 33:493-501. [PMID: 25218252 DOI: 10.1007/s10930-014-9582-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Sea anemones synthesize a variety of toxic peptides and proteins of biological interest. The Caribbean Sea anemone Stichodactyla helianthus, produces two pore-forming toxins, Sticholysin I (St I) and Stichloysin II (St II), with the ability to form oligomeric pores in cell and lipid bilayers characteristically lacking cysteine in their amino acid sequences. Recently, two mutants of a recombinant variant of Sticholysin I (rSt I) have been obtained with a Cys residue in functionally relevant regions for the pore-forming activity of the toxin: r St I F15C (in the amino terminal sequence) and r St I R52C (in the binding site). Aiming at characterizing the effects of oxidants in toxins devoid (r St I) or containing -SH moieties (r St I F15C and r St I R52C), we measured their hemolytic activity and pore forming capacity prior and after their incubation with peroxynitrite (ONOO(-)). At low ONOO(-)/Toxin ratios, nearly 0.8 Trp groups are modified by each added peroxynitrite molecule, and the toxin activity is reduced in ca. 20 %. On the other hand, in -SH bearing mutants only 0.5 Trp groups are modified by each peroxynitrite molecule and the toxin activity is only reduced in 10 %. The results indicated that Cys is the initial target of the oxidative damage and that Trp residues in Cys-containing toxins were less damaged than those in r St I. This relative protection of Trp groups correlates with a smaller loss of hemolytic activity and permeabilization ability in liposomes and emphasizes the relevance of Trp groups in the pore forming capacity of the toxins.
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Affiliation(s)
- L León
- Department of Chemistry, Chemistry and Biology Faculty, Universidad de Santiago de Chile (USACH), Santiago, Chile,
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García-Linares S, Richmond R, García-Mayoral MF, Bustamante N, Bruix M, Gavilanes JG, Martínez-del-Pozo Á. The sea anemone actinoporin (Arg-Gly-Asp) conserved motif is involved in maintaining the competent oligomerization state of these pore-forming toxins. FEBS J 2014; 281:1465-1478. [DOI: 10.1111/febs.12717] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 12/12/2013] [Accepted: 12/31/2013] [Indexed: 01/19/2023]
Affiliation(s)
- Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I; Facultad de Ciencias Químicas; Universidad Complutense; Madrid Spain
| | - Ryan Richmond
- Departamento de Bioquímica y Biología Molecular I; Facultad de Ciencias Químicas; Universidad Complutense; Madrid Spain
| | | | | | - Marta Bruix
- Instituto de Química-Física Rocasolano; Madrid Spain
| | - José G. Gavilanes
- Departamento de Bioquímica y Biología Molecular I; Facultad de Ciencias Químicas; Universidad Complutense; Madrid Spain
| | - Álvaro Martínez-del-Pozo
- Departamento de Bioquímica y Biología Molecular I; Facultad de Ciencias Químicas; Universidad Complutense; Madrid Spain
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Ros U, Edwards MA, Epand RF, Lanio ME, Schreier S, Yip CM, Alvarez C, Epand RM. The sticholysin family of pore-forming toxins induces the mixing of lipids in membrane domains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2757-62. [DOI: 10.1016/j.bbamem.2013.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 11/17/2022]
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