Congratulations to the De La Cruz lab for their recent paper on the the force-dependence of Arp2/3 complex branch dissociation published in PNAS! This study, with contributions from Tom Pollard and visiting professor Ed Taylor, shows the role of mechanical force on the dissociation of branched actin filaments, which was previously unknown. By using TIRF microscopy and microfluidics assays, they discovered the Arp2/3 complex has two states which respond differently to mechanical force and are involved in regulating the dissociation of the branched actin filaments. They also showed that phosphate release from the Arp2/3 complex increases sensitivity to force and debranching proteins. These discoveries create a mechano-chemical understanding of how branched actin networks can respond to forces in cells by adapting growth speed, strength, and architecture.
By Jake Thrasher