Dresden 2017 – wissenschaftliches Programm
BP 21.5: Poster
Dienstag, 21. März 2017, 14:00–16:00, P1A
Flat-to-curved transition of clathrin-mediated endocytosis — •Felix Frey1,2, Delia Bucher3, Kem Sochacki4, Justin Taraska4, Karl Rohr2,5,6, Steeve Boulant3, and Ulrich Schwarz1,2 — 1Institute for Theoretical Physics, Heidelberg University, Germany — 2BioQuant, Heidelberg University, Germany — 3Department of Infectious Diseases, Virology, Heidelberg University, Germany — 4National Institutes of Health, Bethesda, U.S.A. — 5Department of Bioinformatics and Functional Genomics, Heidelberg University, Germany — 6DKFZ, Heidelberg, Germany
The self-assembly of proteins into supramolecular complexes is essential for many cell functions. Examples are the growth of cell adhesion contacts, the formation of the cytoskeleton or the assembly of clathrin-coated vesicles mediating endocytosis. Here we investigate the assembly of flat clathrin arrays at the cell membrane that subsequently reshape to form curved pits. By combining metal replica electron microscopy, correlative light and electron microscopy, live fluorescence microscopy, image analysis and mathematical modeling we demonstrate that acquisition of membrane curvature during clathrin-mediated endocytosis in mammalian cells does not show a linear correlation with clathrin coat assembly. Instead we show that clathrin structures first grow flat and then undergo a substantial ultra-structural reorganization prior to invagination of the plasma membrane. We determine at what stage of coat assembly curvature occurs and demonstrate a relation to plasma membrane tension.