סמינר בכימיה פיזיקלית: In-vitro robust cell-mimicking actin cortex: Mechanistic emergence from basic components

Zoom: https://tau-ac-il.zoom.us/j/87820055721?pwd=kewAaVRPgfvQXtUuQD41aWPtcLcecQ.1

Abstract:

Cell shape deformation in eukaryotes, is primarily determined by the actin cortex, a thin network of actin filaments and myosin molecular motors that lies beneath and attached to the plasma membrane of cells and endows cells with their mechanical stability and structural integrity. Since inside the cells there are hundreds of proteins associated with the actin cortex, it is very difficult to identify the role of each component and the mechanisms that maintain a functional cortex. Here, using a minimal set of components, we recreate in-vitro dynamic treadmilling in an actomyosin cortex on a bilayer membrane with cell-mimicking characteristics, in the absence and presence of myosin-II molecular motors. Moreover, we mechanistically reveal the treadmilling regulation by actin network disassembly factors and myosin contractility, which results in robustness of the cortical thickness to concentration fluctuations in cytoskeletal components. In my seminar I will also describe possible mechanisms that underly 3D shape deformation in these systems, which may reveal potential shared mechanisms with living systems across scales.

Relevant Publication:

Ideses, Y., ...., ABG, 2018, Spontaneous buckling of poroelastic actomyosin sheets, Nature Communications 6, 2461-13

Livne, G., ...., ABG, 2024, Self-assembled active actomyosin gels spontaneously curve and wrinkle similar to biological cells and tissues. PNAS 121 e2309125121.

ABG, ...., Teresi, L., 2024, Interplay between activity, elasticity and liquid transport in self-contractile biopolymer gels. Phys. Rev. E, 109, 014601

Gat, S., Amit, Y., Livne, G., Sanchez, DS, Porat, N, Yochelis, A., Gov, NS., and ABG, Actin turnover and myosin contractility determine emergent Thickness Robustness of Cell-Mimicking Cortex (https://biorxiv.org/cgi/content/short/2024.11.04.621887v1).

מארגן הסמינר: ד"ר ברק הירשברג