Severing Mechanism of Actin Filaments Revealed by De La Cruz and Sindelar labs

Image of Associate Professor Sindelar and Professor De La Cruz
February 7, 2020

Congratulations to the Sindelar and De La Cruz labs on their recent article in PNAS that uses cryo-EM to reveal structures of the cytoskeletal regulatory factor cofilin ‘caught in the act’ of severing actin filaments. Cofilin is a crucial component of the cellular motility apparatus, helping to modulate the force producing polymerization of actin through its cooperative binding and severing activity. Previously, the visualization of the mechanisms of cofilin-mediated severing using existing cryo-EM methods was hindered because the cofilin binding breaks the symmetry of the actin filament. The Sindelar and De La Cruz labs were able to overcome this obstacle by developing a new method to analyze cryo-EM samples of the cofilin decorated actin filaments. The models obtained from this method allowed the groups to directly investigate the conformational states involved in the severing and cooperative binding.

Read their article in PNAS: “Structures of cofilin-induced structural changes reveal local and asymmetric perturbations of actin filaments.”

By Jake Thrasher