Physics-Biology interface seminar: Stéphane Vassilopoulos

Native membrane visualization by meta-replica electron microscopy

Stéphane Vassilopoulos (Sorbonne Université)

In cell biology, particular Importance is given to developing new methods of sample preparation that will achieve a more natural appearance of samples in the microscope. To accomplish this, scientists have developed the metal-replica electron microscopy (EM) technique directly on unroofed cultured cells. This particular EM technique permits visualization of the inner side of cell membranes and their components with an extremely high resolution using transmission EM. Metal-replicas have profoundly shaped our understanding of the functional morphology of the cell and used to capture several different cellular processes including remodeling of cytoskeletons, membrane trafficking, cell-to-cell contacts and formation of extracellular matrices. During this presentation, I will outline the history of this particular EM technique and describe different methodologies and key applications in cell biology with a particular emphasis on visualization of actin filament networks at the cell cortex.

Selected publications:

Vassilopoulos S*, Gibaud S, Jimenez A, Caillol G, Leterrier C. Ultrastructure of the axonal periodic scaffold reveals a braid-like organization of actin rings. Nat Commun. 2019 Dec 20;10(1):5803.
Ferrari R*, Martin G, Tagit O, Guichard A, Cambi A, Voituriez R, Vassilopoulos S*, Chavrier P*. MT1-MMP directs force-producing proteolytic contacts that drive tumor cell invasion. Nat Commun. 2019 Oct 25;10(1):4886.

Franck A, Lainé J, Moulay G, Lemerle E, Trichet M, Gentil C, Benkhelifa-Ziyyat S, Lacène E, Bui MT, Brochier G, Guicheney P, Romero N, Bitoun M, Vassilopoulos S*. Clathrin plaques and associated actin anchor intermediate filaments in skeletal muscle. Mol Biol Cell. 2019 Mar 1;30(5):579-590.
Randrianarison-Huetz V, Papaefthymiou A, Herledan G, Noviello C, Faradova U, Collard L, Pincini A, Schol E, Decaux JF, Maire P, Vassilopoulos S, Sotiropoulos A. Srf controls satellite cell fusion through the maintenance of actin architecture. J Cell Biol. 2018 Feb 5;217(2):685-700.

Elkhatib N, Bresteau E, Baschieri F, Rioja AL, van Niel G, Vassilopoulos S, Montagnac G. Tubular clathrin/AP-2 lattices pinch collagen fibers to support 3D cell migration. Science. 2017 Jun 16;356(6343).

Vassilopoulos S*, Gentil C, Lainé J, Buclez PO, Franck A, Ferry A, Précigout G, Roth R, Heuser JE, Brodsky FM, Garcia L, Bonne G, Voit T, Piétri-Rouxel F, Bitoun M. Actin scaffolding by clathrin heavy chain is required for skeletal muscle sarcomere organization. J Cell Biol. 2014 May 12;205(3):377-93.


Date/Time : 29/01/2020 - 11:00 - 12:00

Location : Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530

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