FIGURE 2.

Schematic representation of dystrophin and utrophin glycoprotein complexes (DGC/UGC). (A) Dystrophin glycoprotein complex (DGC) and (B) utrophin glycoprotein complex (UGC) consist of dystrophin (or utrophin), syntrophins, dystrobrevins, sarcoglycans, sarcospan and dystroglycans distributed in cytoplasmic, transmembrane and extracellular protein complex. The cytoplasmic part includes α1 and β1 syntrophin isoforms and α‐dystrobrevin; transmembrane part includes the sarcoglycan (α, β, γ, δ) and sarcospan complex. Dystroglycan complex consists in the extracellular component, α‐dystroglycan (α‐DG) which binds to agrin and laminin in the extracellular matrix and the transmembrane isoform β‐dystroglycan (β‐DG). Biglycan is another extracellular matrix component of the DGC/UGC that binds to α‐dystroglycan and α‐ and γ‐sarcoglycan [22]. Finally, β‐DG binds to dystrophin or utrophin, completing the link between the actin‐based cytoskeleton and the extracellular matrix [23]. Furthermore, utrophin is associated with large acetylcholine receptors (AChR) clusters at the crests of post‐junctional folds in neuromuscular junctions (NMJs) [24]. Notice that the main differences between dystrophin and utrophin are their lateral interactions with actin and the impossibility of the UGC to recruit nNOS. Created with BioRender.com