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This content will become publicly available on February 8, 2022

Title: Dissociation Mechanisms of G-actin Subunits Govern Deformation Response of Actin Filament
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Award ID(s):
1946202 2019077
Publication Date:
Journal Name:
Page Range or eLocation-ID:
907 to 917
Sponsoring Org:
National Science Foundation
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  3. Abstract

    The proteins that make up the actin cytoskeleton can self-assemble into a variety of structures. In vitro experiments and coarse-grained simulations have shown that the actin crosslinking proteins α-actinin and fascin segregate into distinct domains in single actin bundles with a molecular size-dependent competition-based mechanism. Here, by encapsulating actin, α-actinin, and fascin in giant unilamellar vesicles (GUVs), we show that physical confinement can cause these proteins to form much more complex structures, including rings and asters at GUV peripheries and centers; the prevalence of different structures depends on GUV size. Strikingly, we found that α-actinin and fascin self-sort intomore »separate domains in the aster structures with actin bundles whose apparent stiffness depends on the ratio of the relative concentrations of α-actinin and fascin. The observed boundary-imposed effect on protein sorting may be a general mechanism for creating emergent structures in biopolymer networks with multiple crosslinkers.

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