title: Histones cause aggregation and fusion of lipid vesicles containing phosphatidylinositol-4-phosphate.
abstract: In a previous article, we demonstrated that histones (H1 or histone octamers) interact with negatively charged bilayers and induce extensive aggregation of vesicles containing phosphatidylinositol-4-phosphate (PIP) and, to a lesser extent, vesicles containing phosphatidylinositol (PI). Here, we found that vesicles containing PIP, but not those containing PI, can undergo fusion induced by histones. Fusion was demonstrated through the observation of intervesicular mixing of total lipids and inner monolayer lipids, and by ultrastructural and confocal microscopy studies. Moreover, in both PI- and PIP-containing vesicles, histones caused permeabilization and release of vesicular aqueous contents, but the leakage mechanism was different (all-or-none for PI and graded release for PIP vesicles). These results indicate that histones could play a role in the remodeling of the nuclear envelope that takes place during the mitotic cycle.
authors.affiliation: Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Leioa, Spain; Departamento de Bioquímica, Universidad del País Vasco, Leioa, Spain.
authors.forename: Marta G
authors.initials: MG
authors.lastname: Lete
authors.affiliation: Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Leioa, Spain; Departamento de Bioquímica, Universidad del País Vasco, Leioa, Spain.
authors.forename: Jesus
authors.initials: J
authors.lastname: Sot
authors.affiliation: Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, Derio, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Gil
authors.affiliation: Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, Derio, Spain.
authors.forename: Mikel
authors.initials: M
authors.lastname: Valle
authors.affiliation: Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, Spain; Instituto de Biocomputación y Física de Sistemas Complejos, Unidad Asociada BIFI-IQFR, Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: Milagros
authors.initials: M
authors.lastname: Medina
authors.affiliation: Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Leioa, Spain; Departamento de Bioquímica, Universidad del País Vasco, Leioa, Spain.
authors.forename: Felix M
authors.initials: FM
authors.lastname: Goñi
authors.affiliation: Unidad de Biofísica (CSIC, UPV/EHU), Universidad del País Vasco, Leioa, Spain; Departamento de Bioquímica, Universidad del País Vasco, Leioa, Spain. Electronic address: alicia.alonso@ehu.es.
authors.forename: Alicia
authors.initials: A
authors.lastname: Alonso
mesh_terms: D006657:Histones / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008561:Membrane Fusion; D018129:Phosphatidylinositol Phosphates / Q000737:chemistry*
chemical_list: D006657:Histones; D008081:Liposomes; D018129:Phosphatidylinositol Phosphates; C037178:phosphatidylinositol 4-phosphate