F-actin architecture determines constraints on myosin thick filament motion.

Camelia G Muresan, Zachary Gao Sun, Vikrant Yadav, A Pasha Tabatabai, Laura Lanier, June Hyung Kim, Taeyoon Kim, Michael P Murrell

Nature communications 2022 Nov 16

filter terms:

Active stresses are generated and transmitted throughout diverse F-actin architectures within the cell cytoskeleton, and drive essential behaviors of the cell, from cell division to migration. However, while the impact of F-actin architecture on the transmission of stress is well studied, the role of architecture on the ab initio generation of stresses remains less understood. Here, we assemble F-actin networks in vitro, whose architectures are varied from branched to bundled through F-actin nucleation via Arp2/3 and the formin mDia1. Within these architectures, we track the motions of embedded myosin thick filaments and connect them to the extent of F-actin network deformation. While mDia1-nucleated networks facilitate the accumulation of stress and drive contractility through enhanced actomyosin sliding, branched networks prevent stress accumulation through the inhibited processivity of thick filaments. The reduction in processivity is due to a decrease in translational and rotational motions constrained by the local density and geometry of F-actin. © 2022. The Author(s).

Citation

Camelia G Muresan, Zachary Gao Sun, Vikrant Yadav, A Pasha Tabatabai, Laura Lanier, June Hyung Kim, Taeyoon Kim, Michael P Murrell. F-actin architecture determines constraints on myosin thick filament motion. Nature communications. 2022 Nov 16;13(1):7008