High-speed depolymerization at actin filament ends jointly catalysed by Twinfilin and Srv2/CAP.

ABSTRACT: Purified actin filaments depolymerize slowly, and cytosolic conditions strongly favour actin assembly over disassembly, which has left our understanding of how actin filaments are rapidly turned over in vivo incomplete. One mechanism for driving filament disassembly is severing by factors such as Cofilin. However, even after severing, pointed-end depolymerization remains slow and unable to fully account for observed rates of actin filament turnover in vivo. Here we describe a mechanism by which Twinfilin and Cyclase-associated protein work in concert to accelerate depolymerization of actin filaments by 3-fold and 17-fold at their barbed and pointed ends, respectively. This mechanism occurs even under assembly conditions, allowing reconstitution and direct visualization of individual filame

SUBMITTER: Johnston AB 

PROVIDER: S-EPMC4808055 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature