Receptors for laminins during epithelial morphogenesis.

Laminin-1 is expressed by many embryonic epithelial cell types. It binds to receptors on the epithelial cell surface. The integrin alpha6beta1 is a well known laminin-1 receptor that is expressed on many embryonic epithelial cells. More recently, dystroglycan was discovered as a high-affinity receptor for laminin-1 and laminin-2. It is expressed not only by muscle cells but also by embryonic epithelial cells. In embryonic epithelia, dystroglycan may act by binding to the E3 fragment of laminin-1. Integrins and the dystroglycan complex seems to be important for epithelial morphogenesis, but the relative roles of these two receptor systems for epithelial cells are still unclear.