The interaction between epithelial cells and the extracellular matrix (ECM)is crucial for epithelial morphogenesis. One component of this interaction is Dystroglycan (Dg), a cellular receptor that links the ECM to the cytoskeleton. On , Schneider and colleagues report that Dg interacts with the ECM ligand - Perlecan (Pcan)- to promote and maintain epithelial polarity in the Drosophilafollicle cell epithelium. The researchers report that follicle cells that lack Pcan (trol mutant cells) develop polarity defects similar to those seen in Dg mutant cells, and show that Dg and Pcan interact in vitro. They also show that Dg depends on Pcan but not on laminin (another ECM ligand of Dg) for its localization in the basal membrane domain of follicle cells. Dg promotes the differentiation of this cellular domain, the authors report, by recruiting/anchoring the cytoplasmic protein Dystrophin and excluding Neurexin, a basolateral protein. Given these results, the researchers propose that Pcan and Dg interact to promote and maintain polarity in this epithelium.
