title: On the role of membrane anisotropy and BAR proteins in the stability of tubular membrane structures.
abstract: Recent studies have demonstrated that actin filaments are not crucial for the short-term stability of tubular membrane protrusions originating from the cell surface. It has also been demonstrated that prominin nanodomains and curvature inducing I-BAR proteins could account for the stability of the membrane protrusion. Here we constructed an axisymmetric model of a membrane protrusion that excludes actin filaments in order to investigate the contributions of prominin nanodomains (rafts) and I-BAR proteins to the membrane protrusion stability. It was demonstrated that prominin nanodomains and I-BAR proteins can stabilize the membrane protrusion only over a specific range of spontaneous curvature. On the other hand, high spontaneous curvature and/or high density of I-BAR proteins could lead to system instability and to non-uniform contraction in the radial direction of the membrane protrusion. In agreement with previous studies, it was also shown that the isotropic bending energy of lipids is not sufficient to explain the stability of the observed tubular membrane protrusion without actin filaments.
authors.affiliation: Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia. doron.kabaso@fe.uni-lj.si
authors.forename: Doron
authors.initials: D
authors.lastname: Kabaso
authors.forename: Nataliya
authors.initials: N
authors.lastname: Bobrovska
authors.forename: Wojciech
authors.initials: W
authors.lastname: Góźdź
authors.forename: Nir
authors.initials: N
authors.lastname: Gov
authors.forename: Veronika
authors.initials: V
authors.lastname: Kralj-Iglič
authors.forename: Peter
authors.initials: P
authors.lastname: Veranič
authors.forename: Aleš
authors.initials: A
authors.lastname: Iglič
mesh_terms: D000071916:AC133 Antigen; D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D016880:Anisotropy; D015703:Antigens, CD / Q000378:metabolism; D021961:Cell Membrane Structures / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism; D008954:Models, Biological; D010455:Peptides / Q000378:metabolism; D017434:Protein Structure, Tertiary
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D008563:Membrane Lipids; D010455:Peptides