Interaction of EpCAM with Claudin-7 inhibits myosin activity in cortical F-actin and slows epithelial migration.
(A) Proposed model of a pathway in which EpCAM/Claudin-7 complexes at cell-cell junctions inhibit ERK activity and myosin contractility in cortical F-actin. (B) Epithelial sheets with high EpCAM levels have low phospho-ERK levels and low phospho-myosin in cortical F-actin making it more difficult for cells at the edge to disrupt cortical F-actin bundles and extend lamellipodia. (C) Epithelial sheets with low EpCAM levels have high phospho-ERK levels and high phospho-myosin in cortical F-actin. Increased actomyosin contractility makes it easier for cells at the edge to disrupt cortical F-actin bundles and extend lamellipodia.