LET-413 is a basolateral protein required for the assembly of adherens junctions in Caenorhabditis elegans

Epithelial cells are polarized, with apical and basal compartments demarcat ed by tight and adherens junctions. Proper establishment of these subapical junctions is critical for normal development and histogenesis, We report t he characterization of the gene let-413 which has a critical role in assemb ling adherens junctions in Caenorhabditis elegans, In let-413 mutants, adhe rens junctions are abnormal and mislocalized to more basolateral positions, epithelial cell polarity is affected and the actin cytoskeleton is disorga nized. The LET-413 protein contains one PDZ domain and 16 leucine-rich repe ats with high homology to proteins known to interact with small GTPases, St rikingly, LET-413 localizes to the basolateral membrane. We suggest that LE T-413 acts as an adaptor protein involved in polarizing protein trafficking in epithelial cells.