Figure 1
From: Fukuyama-type congenital muscular dystrophy and defective glycosylation of α-dystroglycan
The dysfunction of α-dystroglycan in Fukuyama-type congenital MD (FCMD). (A) The normal dystrophin-glycoprotein complex (DGC) in skeletal muscle. α-dystroglycan binds to laminin via the O-linked glycan chain moiety, including Siaα2-3Galβ1-4GlcNAcβ1-2Man and a phosphoryl glycan attached to the mannose. Details of the postphosphoryl glycan modification are still unknown. The N-terminal domain of α-dystroglycan is cleaved by furin and secreted. (B) The DGC in FCMD. The mutation in fukutin causes defects in postphosphoryl modification of the O-linked glycan, resulting in disruption of the linkage between α-dystroglycan and laminin, and leading to destabilization of the sarcolemma. The modification of O-linked mannose by Siaα2-3Galβ1-4GlcNAcβ remains to be elucidated in FCMD.