FIGURE 7.
Model representing mode of Aip1 action on cofilin-actin filaments. (A) Cofilin alone binds to the filament and alters the angular configuration of actin protomers within the polymer lattice. Severing is caused due to unstable heterotypic junctions between cofilin-bound and unbound regions on the actin filament. (B) Aip1 preferentially binds stretches of actin polymer occupied with cofilin leading to enhanced severing and faster disassembly from both barbed and pointed ends. (C) In the presence of Aip1, cofilin-saturated filaments are no longer stable and can be destabilized.