Abstract
The Schwann cell basal lamina acts as an organizer of peripheral nerve tissue and influences many aspects of cell behavior during development and regeneration. A principal component of the Schwann cell basal lamina is laminin‐2. This study was undertaken to identify Schwann cell receptors for laminin‐2. We found that among several Schwann cell integrins that can potentially interact with laminin‐2, only α7β1 bound to laminin‐2‐Sepharose. Dystroglycan, a non‐integrin Schwann cell receptor for laminin‐2 identified previously, was also found to bind to laminin‐2‐Sepharose. Antibody to the α7 integrin subunit partially inhibited Schwann cell adhesion to laminin‐2. Small interfering RNA‐mediated suppression of either α7 integrin or dystroglycan expression decreased adhesion and spreading of Schwann cells on laminin‐2, whereas knocking down both proteins together inhibited adhesion and spreading on laminin‐2 almost completely. α7 integrin and dystroglycan both colocalized with laminin‐2 containing basal lamina tubes in differentiating neuron–Schwann cell cocultures. The α7β1 integrin also coprecipitates with focal adhesion kinase in differentiating cocultures. These findings strongly suggest that α7β1 integrin is a Schwann cell receptor for laminin‐2 that provides transmembrane linkage between the Schwann cell basal lamina and cytoskeleton. © 2007 Wiley‐Liss, Inc.