Heraclitus and the cytoskeleton: the role of force feedback in molecular self-assembly
The mechanical properties of most eukaryotic cells is determined by the actin cytoskeleton. A major challenge to understanding the physical properties of actin networks, however, is that they are dynamic: their assembly and disassembly are integral to their function. External forces are particularly relevant to ‘dendritic’ actin networks, generated by the nucleating and crosslinking activity of the Arp2/3 complex, a seven-subunit protein complex that builds crosslinked filament arrays by creating new filaments that branch from the sides of existing filaments.