Localization of mLin-7 at nectin-based cell–cell junctions

Abstract

In C. elegans, lin-7 as well as lin-2/lin-10 is involved in the proper localization of the LET-23 receptor tyrosine kinase that regulates vulval induction. The mammalian homologue, mLin-7, forms a ternary complex with the mammalian homologues of LIN-2 and LIN-10 and localizes at cell–cell junctions in epithelial cells, but the mechanism of this localization of mLin-7 is unknown. Nectin is an immunoglobulin-like cell–cell adhesion molecule that is involved in organization of adherens and tight junctions in epithelial cells. Nectin is indirectly associated with the cadherin–catenin system and the actin cytoskeleton through afadin, an actin filament-binding protein. We showed here that mLin-7 localized at the nectin-based cell–cell junctions. This localization of mLin-7 required the interaction of nectin with afadin, but not the cadherin–catenin system or the actin cytoskeleton. mLin-7 did not directly interact with nectin or afadin. The results indicate that mLin-7 localizes at cell–cell junctions through the nectin–afadin system.