Figure 1.

The dystrophin glycoprotein complex (DGC) in a skeletal muscle cell. Shown are the interactions among core components of the DGC, the extracellular matrix, and nNOS. Numbers in dystrophin indicate hinge regions (H1, H2, etc.) and spectrin-like repeat domains (4, 8, 12, etc.). However, nNOS is not associated with DGC in a cardiomyocyte (see the text for detail). nNOS, neuronal nitric oxide synthase; Syn, syntrophin; SSPN, sarcospan; ABD, actin binding domain; DBD, dystroglycan binding domain; SBS, syntrophin binding site; CC, coiled-coil domain; N, amino terminus; C, carboxy terminus. Obtained from Allen DG, Whitehead NP, and Froehner SC, “Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca²⁺, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy” Physiol. Rev. 2016, 96, 253–305, under copyright agreement.