Delta-sarcoglycan

Delta-sarcoglycan is a protein that in humans is encoded by the SGCD gene. It is a component of the sarcoglycan complex, a subcomplex of the larger dystrophin-glycoprotein complex (DGC) which serves a vital role in muscle function.

Structure

Delta-sarcoglycan is a 35 kDa transmembrane protein that is predominantly expressed in striated muscle. The SGCD gene, located on chromosome 5 at position 5q33-q34, spans approximately 4.4 kilobases and contains 7 exons. The protein encoded by this gene is part of the sarcoglycan complex, which includes alpha-sarcoglycan, beta-sarcoglycan, and gamma-sarcoglycan.

Function

The sarcoglycan complex contributes to the stability of the DGC in muscle and serves to link the cytoskeleton of muscle fibers to the extracellular matrix, helping to protect muscle fibers from mechanical stress. Delta-sarcoglycan also appears to play a role in the membrane localization of other sarcoglycans.

Clinical significance

Mutations in the SGCD gene are associated with limb-girdle muscular dystrophy type 2F (LGMD2F), a form of muscular dystrophy characterized by progressive muscle wasting and weakness. Symptoms typically begin in childhood or adolescence and primarily affect the pelvic girdle and shoulder girdle muscles. There is currently no cure for LGMD2F, and treatment is focused on managing symptoms and improving quality of life.

See also

• Sarcoglycan
• Limb-girdle muscular dystrophy
• Dystrophin-glycoprotein complex