Structure And Dynamic States of Actin Filaments

Actin, a highly conserved and ubiquitous eukaryotic protein, underlies essential cellular processes including motility, shape maintenance and muscle contraction. Its dynamic transition between monomeric and filamentous states is powered by ATP hydrolysis, which undergoes structural rearrangements that accelerate turnover in filaments and serve as a measure of filament aging. A wide range of actin binding proteins (ABPs) regulate polymerization, depolymerization, and network organization. Recent high resolution cryo-EM and cryo-ET studies have revealed detailed structures of actin, its isoforms, and ABP complexes, including their organization in cells, deepening our understanding of actin function in health and disease.