Distribution of dystroglycan in normal adult mouse tissues.

Dystroglycan is a cell surface protein which, in muscle, links the extracellular matrix protein laminin-2 to the intracellular cytoskeleton. Dystroglycan also binds laminin-1 and the binding occurs via the E3 fragment of laminin-1. Recently, it was found that dystroglycan is expressed in developing epithelial cells of the kidney. Moreover, antibodies against dystroglycan can perturb epithelial development in kidney organ culture. Therefore, dystroglycan may be an important receptor for cell-matrix interactions in non-muscle tissues. However, information about the tissue distribution of dystroglycan is limited, especially in adult tissues. Here we show that dystroglycan is present in epithelial cells in several non-muscle organs of adult mice. Dystroglycan is enriched towards the basal side of the epithelial cells that are in close contact with basement membranes. We suggest that dystroglycan is involved in linking basement membranes to epithelial and muscle cells. Dystroglycan may be important for the maintenance of tissue integrity.