title: Disrupting a key hydrophobic pair in the oligomerization interface of the actinoporins impairs their pore-forming activity.
abstract: Crystallographic data of the dimeric and octameric forms of fragaceatoxin C (FraC) suggested the key role of a small hydrophobic protein-protein interaction surface for actinoporins oligomerization and pore formation in membranes. However, site-directed mutagenesis studies supporting this hypothesis for others actinoporins are still lacking. Here, we demonstrate that disrupting the key hydrophobic interaction between V60 and F163 (FraC numbering scheme) in the oligomerization interface of FraC, equinatoxin II (EqtII), and sticholysin II (StII) impairs the pore formation activity of these proteins. Our results allow for the extension of the importance of FraC protein-protein interactions in the stabilization of the oligomeric intermediates of StII and EqtII pointing out that all of these proteins follow a similar pathway of membrane disruption. These findings support the hybrid pore proposal as the universal model of actinoporins pore formation. Moreover, we reinforce the relevance of dimer formation, which appears to be a functional intermediate in the assembly pathway of some different pore-forming proteins.
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Haydeé
authors.initials: H
authors.lastname: Mesa-Galloso
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.|Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N1N4, Canada.
authors.forename: Karelia H
authors.initials: KH
authors.lastname: Delgado-Magnero
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Sheila
authors.initials: S
authors.lastname: Cabezas
authors.affiliation: Medical Biochemistry Institute, Federal University of Rio de Janeiro, Cidade Universitária, Ilha do Fundão Rio de Janeiro, CEP: 21.941-902, RJ, Brazil.
authors.forename: Aracelys
authors.initials: A
authors.lastname: López-Castilla
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Hernández-González
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Lohans
authors.initials: L
authors.lastname: Pedrera
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Carlos
authors.initials: C
authors.lastname: Alvarez
authors.affiliation: Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N1N4, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Peter Tieleman
authors.affiliation: Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str.4, Tübingen, 72076, Germany.
authors.forename: Ana J
authors.initials: AJ
authors.lastname: García-Sáez
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Lanio
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.|Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str.4, Tübingen, 72076, Germany.
authors.forename: Uris
authors.initials: U
authors.lastname: Ros
authors.affiliation: Center for Protein Studies, Faculty of Biology, Havana University, Havana, Cuba, Calle 25 # 455, Plaza de la Revolución, La Habana, Cuba.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Valiente
mesh_terms: D003064:Cnidarian Venoms / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D052899:Pore Forming Cytotoxic Proteins / Q000737:chemistry*; D055503:Protein Multimerization
chemical_list: D003064:Cnidarian Venoms; D052899:Pore Forming Cytotoxic Proteins; C545670:fragaceatoxin C; C404794:sticholysin II; C012307:equinatoxin
keywords: dimeric intermediate; molecular dynamic simulations; oligomerization in membranes; pore-forming toxins; protein-lipid pore