The dystrophin glycoprotein complex (DGC) is a membrane-spanning complex that links the interior cytoskeleton to the extracellular matrix in muscle. The sarcoglycan complex is a subcomplex within the DGC and is composed of several muscle-specific, transmembrane proteins (alpha-, beta-, gamma-, delta- and zeta-sarcoglycan). The sarcoglycans are asparagine-linked glycosylated proteins with single transmembrane domains.[2][3]
The disorders caused by the mutations of the sarcoglycans are called sarcoglycanopathies. Mutations in the α, β, γ or δ genes (not ε) encoding these proteins can lead to the associated limb-girdle muscular dystrophy.
^Chockalingam PS, Cholera R, Oak SA, Zheng Y, Jarrett HW, Thomason DB (August 2002). "Dystrophin-glycoprotein complex and Ras and Rho GTPase signaling are altered in muscle atrophy". American Journal of Physiology. Cell Physiology. 283 (2): C500-11. doi:10.1152/ajpcell.00529.2001. PMID12107060.