Regulating actin-filament dynamics in vivo

The assembly and disassembly (i.e. turnover) of actin filaments in response to extracellular signals underlie a wide variety of basic cellular process es such as cell division, endocytosis and motility. The bulk turnover of su bunits is 100-200 times faster in cells than with pure actin, suggesting a complex regulation in vivo. Significant progress has been made recently in identifying and clarifying the roles of several cellular proteins that coor dinately regulate actin-filament turnover.