Structure and assembly of vimentin intermediate filaments

Datum

29.11.2022

Zeit

16:00 - 17:00

Sprecher

Cecile Leduc

Zugehörigkeit

Institut Jacques Monod, Paris, France

Sprache

en

Hauptthema

Biologie

Host

Stefan Diez

Beschreibung

Intermediate filaments (IF) are involved in key cellular functions including polarization, migration, and protection against large deformations. These functions are related to their remarkable ability to extend without breaking, a capacity that should be determined by the molecular organization of subunits within filaments. However, this structure-mechanics relationship remains poorly understood at the molecular level. In the first part of the talk I will present how we showed that vimentin filaments exhibit a ~49 nm axial repeat both in cells and in vitro using super-resolution microscopy (SRM). As unit-length-filaments (ULFs) precursors, which are the building blocks for filament elongation, were measured at ~59 nm, this demonstrates a partial overlap of ULFs during filament assembly. Using an SRM-compatible stretching device, we also provide evidence that the extensibility of vimentin is due to the unfolding of its subunits and not to their sliding, thus establishing a direct link between the structural organization and its mechanical properties (1). In the second part of the talk, I will present how we uncovered the contribution of filament spontaneous fragmentation in the assembly dynamics of type III vimentin IF using a combination of in vitro reconstitution probed by fluorescence imaging and theoretical modeling (2).

Letztmalig verändert: 30.11.2022, 07:38:52