Obligatory role for phospholipase C-γ1in villin-induced epithelial cell migration

Abstract

While there is circumstantial evidence to suggest a requirement for phospholipase C-γ1(PLC-γ1) in actin reorganization and cell migration, few studies have examined the direct mechanisms that link regulators of the actin cytoskeleton with this crucial signaling molecule. This study was aimed to examine the role that villin, an epithelial cell-specific actin-binding protein, and its ligand PLC-γ1play in migration in intestinal and renal epithelial cell lines that endogenously or ectopically express human villin. Basal as well as epidermal growth factor (EGF)-stimulated cell migration was accompanied by tyrosine phosphorylation of villin and its association with PLC-γ1. Inhibition of villin phosphorylation prevented villin-PLC-γ1complex formation as well as villin-induced cell migration. The absolute requirement for PLC-γ1in villin-induced cell migration was demonstrated by measuring cell motility in PLC-γ1−/−cells and by downregulation of endogenous PLC-γ1. EGF-stimulated direct interaction of villin with the Src homology domain 2 domain of PLC-γ1at the plasma membrane was demonstrated in living cells by using fluorescence resonance energy transfer. These results demonstrate that villin provides an important link between the activation of phosphoinositide signal transduction pathway and epithelial cell migration.