Accueil du site > Séminaires > Archives séminaires > Séminaires 2015 > Séminaire MSC. Lundi 09 février 2015 à 11h30. Aurélien Roux (Université de Genève) : "Membrane deformation by buckling of ESCRT spiral springs".
Sauf mention contraire, les séminaires et les soutenances se déroulent à 11h30 en salle 454A du bâtiment Condorcet.
ESCRT-III was genetically and biochemically implicated in membrane deformation and scission of membrane in many membrane remodeling events such as intra-lumenal vesicle formation in multi-vesicular bodies, abscission in cytokinesis and virion budding from the plasma membrane. However, how it breaks and deforms the membrane are still under debate, as the molecular structure of the proteins in the complex do not suggest a mechanism. Here we show that the yeast ESCRT-III protein Snf7 when reconstituted onto supported bilayer forms circular patches that extend by a growing front wave at their rim. The center of the patch is saturated with Snf7 that cannot polymerize anymore. By using High Speed AFM and electron microscopy, we show that these patches are formed of Snf7 spirals that grow into a tight hexagonal array. By using physical modeling, we predict the stop of the growth to be connected to lateral compression of the spirals. Indeed, when grown on free lipid membrane such as giant unilamellar vesicles (GUVs), Snf7 coat can provoke membrane deformations compatible with a model where Snf7 spirals act as 2D spiral springs loaded by polymerization and which release by buckling can cause membrane budding.
Contact : Équipe séminaires / Seminar team - Published on / Publié le 1er octobre 2014
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