Cofilin phosphorylation by LIM-kinase 1 and its role in Rac-mediated actin reorganization

Abstract

Rac is a small GTPase of the Rho family that mediates stimulus-induced actin cytoskeletal reorganization to generate lamellipodia^1,2,3,4,5. Little is known about the signalling pathways that link Rac activation to changes in actin filament dynamics. Cofilin is known to be a potent regulator of actin filament dynamics^6,7,8,9,10, and its ability to bind and depolymerize actin is abolished by phosphorylation of serine residue at 3 (refs 11, 12); however, the kinases responsible for this phosphorylation have not been identified. Here we show that LIM-kinase 1 (LIMK-1), a serine/threonine kinase containing LIM and PDZ domains^13,14,15,16, phosphorylates cofilin at Ser 3, both...