Cofilin-mediated actin filament network flexibility facilitates 2D to 3D actomyosin shape change

Eur J Cell Biol. 2023 Dec 26;103(1):151379. doi: 10.1016/j.ejcb.2023.151379. Online ahead of print.ABSTRACTThe organization of actin filaments (F-actin) into crosslinked networks determines the transmission of mechanical stresses within the cytoskeleton and subsequent changes in cell and tissue shape. Principally mediated by proteins such as α-actinin, F-actin crosslinking increases both network connectivity and rigidity, thereby facilitating stress transmission at low crosslinking yet attenuating transmission at high crosslinker concentration. Here, we engineer a two-dimensional model of the actomyosin cytoskeleton, in which myosin-induced mechanical stresses are controlled by light. We alter the extent of F-actin crosslinking by the introduction of oligomerized cofilin. At pH 6.5, F-actin severing by cofilin is weak, but cofilin bundles and crosslinks filaments. Given its effect of lowering the F-actin bending stiffness, cofilin- crosslinked networks are significantly more flexible and softer in bending than networks crosslinked by α-actinin. Thus, upon local activation of myosin-induced contractile stress, the network bends out-of-plane in contrast to the in-plane compression as observed with networks crosslinked by α-actinin. Here, we demonstrate that local effects on filament mechanics by cofilin introduces novel large-scale network material properties that enable the sculpting of complex shapes in the cell cytoskeleton.PMID:38168598 | DOI:10.1016/j.ejcb.2023.151379

Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Zachary Gao Sun Vikrant Yadav Sorosh Amiri Wenxiang Cao Enrique M De La Cruz Michael Murrell Source Type: research