Analysis of Dystrophin-Associated Glycoproteins: Focus on Expression and Glycosylation of Dystroglycan in Skeletal Muscle.

The dystrophin-associated glycoprotein (DAG) complex includes a number of important transmembrane and membrane-associated proteins that contribute to the maintenance of muscle membrane stability and to signaling through the muscle cell membrane. DAG expression and post-translational modifications can be altered in skeletal muscle from patients with Duchenne muscular dystrophy (DMD) and other forms of muscular dystrophy, making it essential to have robust protocols to assess these features. While good antibody and DNA probes exist to assess expression of most DAGs, quantitative analysis of glycosylation and protein expression for α dystroglycan (αDG) has been problematic. Here we provide protocols to describe proper functional glycosylation and expression of αDG using immunostaining and immunoblotting, demonstrating how such protocols can identify glycosylation defects that give rise to muscular dystrophy.