Interaction of dystrophin with cytoskeletal proteins: binding to talin and actin

Dystrophin, the protein product of the Duchenne gene, is thought to be a member of muscle membrane cytoskeleton. In this work we studied the interactions of purified dystrophin from rabbit skeletal muscle sarcolemma membranes with other cytoskeletal proteins. The interaction of dystrophin with purified talin from chicken gizzard was tested by solid phase immunoassay. Under these conditions dystrophin bound talin with high affinity (Kd 3.5 nM). Vinculin purified from chicken gizzard did not bind dystrophin, but it inhibited the binding of dystrophin to talin. Furthermore, co-sedimentation and solid phase immunoassay experiments both demonstrated that native dystrophin binds purified actin from rabbit skeletal muscle. In conclusion, our results show that dystrophin can interact in vitro with proteins that are members of muscle membrane cytoskeleton. These proteins may represent additional sites for anchoring dystrophin to sarcolemma.