title: The Energy of COPI for Budding Membranes.
abstract: As a major actor of cellular trafficking, COPI coat proteins assemble on membranes and locally bend them to bud 60 nm-size coated particles. Budding requires the energy of the coat assembly to overcome the one necessary to deform the membrane which primarily depends on the bending modulus and surface tension, γ. Using a COPI-induced oil nanodroplet formation approach, we modulated the budding of nanodroplets using various amounts and types of surfactant. We found a Heaviside-like dependence between the budding efficiency and γ: budding was only dependent on γ and occurred beneath 1.3 mN/m. With the sole contribution of γ to the membrane deformation energy, we assessed that COPI supplies ~1500 kBT for budding particles from membranes, which is consistent with common membrane deformation energies. Our results highlight how a simple remodeling of the composition of membranes could mechanically modulate budding in cells.
authors.affiliation: Laboratoire de Physique Statistique, Ecole Normale Supérieure de Paris, Université Pierre et Marie Curie, Université Paris Diderot, Centre National de la Recherche Scientifique, 24 rue Lhomond, 75005, Paris, France; Department of Cell Biology, School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, United States of America.
authors.forename: Abdou Rachid
authors.initials: AR
authors.lastname: Thiam
authors.affiliation: Laboratoire de Physique Statistique, Ecole Normale Supérieure de Paris, Université Pierre et Marie Curie, Université Paris Diderot, Centre National de la Recherche Scientifique, 24 rue Lhomond, 75005, Paris, France; Department of Cell Biology, School of Medicine, Yale University, 333 Cedar Street, New Haven, CT 06520, United States of America.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pincet
mesh_terms: D001692:Biological Transport; D022181:COP-Coated Vesicles / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology*; D020755:Coat Protein Complex I / Q000378:metabolism*; D004734:Energy Metabolism; D006801:Humans; D013500:Surface Tension
chemical_list: D020755:Coat Protein Complex I