DAG1 (Dystroglycan, Dystrophin-associated Glycoprotein 1, Alpha-dystroglycan, alpha-DG)

Alpha-dystroglycan (alpha-DG), also known as dystrophin-associated glycoprotein, is a laminin-binding protein of ~156kD (including glyco-groups). Alpha-DG is a component of the dystroglycan complex, which is involved in early development, morphogenesis and in the pathogenesis of muscular dystrophies. Alpha- and beta-DG are encoded by a single gene and are derived from a precursor polypeptide by posttranslational cleavage. Beta-DG is an integral membrane protein, whereas alpha-DG is membrane- associated through its noncovalent interaction with the extracellular domain of beta-DG. The alpha- and beta-DGs provide important physical linkages between components of basement membranes and cytoplasmic proteins that bind to the actin cytoskeleton. Alpha-DG is a heavily glycosylated, mucin-like protein anchored on the extracellular surface of the myotube, where it may provide linkage between the sarcolemma and extracellular matrix (ECM). Alpha-DG is expressed in a variety of fetal and adult tissues. Tissue-specific glycosylation modifies the laminin specificity of alpha-DG. The muscle and nonmuscle isoforms of dystroglycan differ by carbohydrate moieties but not protein sequence. Alpha-DG has been shown to colocalize with laminin in skeletal and cardiac muscle and a number of other cells including peripheral nerve, astrocytes, Purkinje neurons and kidney epithelium. Laminin-10/11 was shown to bind preferentially to brain alpha-DG. In Duchenne muscular dystrophy, the expression of alpha-DG is dramatically reduced leading to a loss of linkage between the sarcolemma and extracellular matrix, rendering muscle fibers more susceptible to necrosis. In the central nervous system, dystroglycan functions as a dual receptor for agrin and laminin-2 for instance in the Schwann cell membrane. Furthermore, defects in dystroglycan are central to the pathogenesis of structural and functional brain abnormalities seen in congenital muscular dystrophies (CMD). Applications: Suitable for use in Western Blot, ELISA and Immunohistochemistry. Other applications not tested. Recommended Dilution: Western Blot: 1:50 Immunohistochemistry: Paraffin Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.