Putting a new twist on actin: ADF/cofilins modulate actin dynamics

The actin-depolymerizing factor (ADF)/cofilins are a family of essential ac tin regulatory proteins, ubiquitous among eukaryotes, that enhance the turn over of actin by regulating the rate constants of polymerization and depoly merization at filament ends, changing the twist of the filament and serving actin filaments. Genetic and cell-biological studies have shown that an AD F/cofilin is required to drive the high turnover of the actin cytoskeleton observed in vivo. The activity of ADF/cofilin is regulated by a variety of mechanisms, including specific phosphorylation. This review addresses aspec ts of ADF/cofilin structure, dynamic, regulation and function.