title: Opening of holes in liposomal membranes is induced by proteins possessing the FERM domain.
abstract: The destabilization of vesicles caused by interactions between lipid bilayers and proteins was studied by direct, real-time observation using high-intensity dark-field microscopy. We previously reported that talin, a cytoskeletal submembranous protein, can reversibly open stable large holes in giant liposomes made of neutral and acidic phospholipids. Talin and other proteins belonging to the band 4.1 superfamily have the FERM domain at their N-terminal and interact with lipid membranes via that domain. Here, we observed that band 4.1, ezrin and moesin, members of the band 4.1 superfamily, are also able to open stable holes in liposomes. However, truncation of their C-terminal domains, which can interact with the N-terminal FERM domain, impaired their hole opening activities. Oligomeric states of ezrin affected the capability of the membrane hole formation. Phosphatidylinositol bisphosphate (PIP2), which binds to the FERM domain and disrupts the interaction between the N and C termini of the band 4.1 superfamily, down-regulates their membrane opening activity. These results suggest that the intermolecular interaction plays a key role in the observed membrane hole formation.
authors.affiliation: Department of Molecular Biology, School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Takeda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Saitoh
authors.forename: Mayumi
authors.initials: M
authors.lastname: Furuta
authors.forename: Nao
authors.initials: N
authors.lastname: Satomi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ishino
authors.forename: Gakushi
authors.initials: G
authors.lastname: Nishida
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sudo
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hotani
authors.forename: Kingo
authors.initials: K
authors.lastname: Takiguchi
mesh_terms: D000818:Animals; D002645:Chickens; D002784:Cholesterol / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000378:metabolism*; D019281:Dimerization; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008840:Microfilament Proteins / Q000737:chemistry / Q000378:metabolism; D008954:Models, Biological; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016608:Talin / Q000737:chemistry / Q000378:metabolism; D000099149:Ezrin
chemical_list: D002784:Cholesterol; D003598:Cytoskeletal Proteins; D008081:Liposomes; D008565:Membrane Proteins; D008840:Microfilament Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D016608:Talin; D000099149:Ezrin; C028841:erythrocyte membrane band 4.1 protein; C071058:moesin