Bending forces and nucleotide state jointly regulate F-actin structure.

ABSTRACT: ATP-hydrolysis-coupled actin polymerization is a fundamental mechanism of cellular force generation^1-3. In turn, force^4,5 and actin filament (F-actin) nucleotide state⁶ regulate actin dynamics by tuning F-actin's engagement of actin-binding proteins through mechanisms that are unclear. Here we show that the nucleotide state of actin modulates F-actin structural transitions evoked by bending forces. Cryo-electron microscopy structures of ADP-F-actin and ADP-P_i-F-actin with sufficient resolution to visualize bound solvent reveal intersubunit interfaces bridged by water molecules that could mediate filament lattice flexibility. Despite extensive ordered solvent differences in the nucleotide cleft, these structures feature nearly identical lattices a

SUBMITTER: Reynolds MJ 

PROVIDER: S-EPMC9646526 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature