Selforganizaton of the Cytoskeleton

Group: Bausch

Date: 2021

The cell cytoskeleton, or cell skeleton, is composed of filaments (actin, microtubules, intermediate filaments) which not only provide mechanical stability but also dynamic flexibility, allowing the cell to change shape, divide, migrate etc. To do that, they are tightly regulated by the cell, they are able to (dis)assemble when needed, they couple to the cell membrane or various cell’s organelles and, importantly, to a huge set of other proteins, including cytoskeletal motors (myosin, kinesin, dynein) that are able to exert mechanical forces on them. All these elements together show impressive self-assembly properties and are able to organize in complex structures, from the cytokinetic ring to the mitotic spinde, in order to perform their functions.

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We study the active self assembly of filaments and membranes by merging together in vitro membrane model systems (such as giant vesicles or supported membranes) and cytoskeletal proteins (especially filaments and motors). By using microscopy techniques such as confocal and TIRF we can observe, control and study in laboratory conditions the formation of complex patterns, from the assembly of filaments into clusters up to their ability to move coherently as a fluid and deform lipid membranes. This way, we are able to explore the mechanisms underlying filaments’ dynamics, collective motion or how these processes are affected by different environments, such as being immersed in complex elastic materials or confined inside vesicles.

This research can shed light on general principles about how cells tune the out-of-equilibrium assembly of the cytoskeleton, in order to perform a varied and vast number of different tasks.