Skip to main content
eScholarship
Open Access Publications from the University of California

Cofilin-induced changes in F-actin detected via cross-linking with benzophenone-4-maleimide

  • Author(s): Chen, CK
  • Benchaar, SA
  • Phan, M
  • Grintsevich, EE
  • Loo, RRO
  • Loo, JA
  • Reisler, E
  • et al.

Published Web Location

https://doi.org/10.1021/bi400715z
Abstract

Cofilin is a member of the actin depolymerizing factor (ADF)/cofilin family of proteins. It plays a key role in actin dynamics by promoting disassembly and assembly of actin filaments. Upon its binding, cofilin has been shown to bridge two adjacent protomers in filamentous actin (F-actin) and promote the displacement and disordering of subdomain 2 of actin. Here, we present evidence for cofilin promoting a new structural change in the actin filament, as detected via a switch in cross-linking sites. Benzophenone-4-maleimide, which normally forms intramolecular cross-linking in F-actin, cross-links F-actin intermolecularly upon cofilin binding. We mapped the cross-linking sites and found that in the absence of cofilin intramolecular cross-linking occurred between residues Cys374 and Asp11. In contrast, cofilin shifts the cross-linking by this reagent to intermolecular, between residue Cys374, located within subdomain 1 of the upper protomer, and Met44, located in subdomain 2 of the lower protomer. The intermolecular cross-linking of F-actin slows the rate of cofilin dissociation from the filaments and decreases the effect of ionic strength on cofilin-actin binding. These results are consistent with a significant role of filament flexibility in cofilin-actin interactions. © 2013 American Chemical Society.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View