Remodeling of actin filaments by ADF/cofilin proteins

• Published in: Proceedings of the National Academy of Sciences - PNAS 2011-12, Vol.108 (51), p.20568-20572
• Main Authors: Galkin, Vitold E, Orlova, Albina, Kudryashov, Dmitri S, Solodukhin, Alexander, Reisler, Emil, Schröder, Gunnar F, Egelman, Edward H
• Format: Article
• Language: English
• Subjects: actin; Actin depolymerizing factors; Actin Depolymerizing Factors - chemistry; Actins; Actins - chemistry; Atoms; Biochemistry; Biological Sciences; Cofilin 2 - chemistry; Cryoelectron Microscopy - methods; Cytoskeleton - chemistry; Eukaryotes; Gene Library; Humans; Microfilaments; microscopy; Microscopy, Electron - methods; Models, Molecular; Molecular Conformation; Molecules; Muscle, Skeletal - metabolism; Pixels; Polymers - chemistry; Protein Conformation; Protein Structure, Secondary; Protein subunits; Proteins; Yeasts
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1110109108

Cofilin/ADF proteins play key roles in the dynamics of actin, one of the most abundant and highly conserved eukaryotic proteins. We used cryoelectron microscopy to generate a 9-Å resolution three-dimensional reconstruction of cofilin-decorated actin filaments, the highest resolution achieved for a complex of F-actin with an actin-binding protein. We show that the cofilin-induced change in the filament twist is due to a unique conformation of the actin molecule unrelated to any previously observed state. The changes between the actin protomer in naked F-actin and in the actin-cofilin filament are greater than the conformational changes between G- and F-actin. Our results show the structural plasticity of actin, suggest that other actin-binding proteins may also induce large but different conformational changes, and show that F-actin cannot be described by a single molecular model.