Dystroglycan is one of the dystrophin-associated glycoproteins, which is encoded by a 5.5 kb transcript in Homo sapiens on chromosome 3. There are two exons that are separated by a large intron. The spliced exons code for a protein product that is finally cleaved into two non-covalently associated subunits, [alpha] (N-terminal) and [beta] (C-terminal).
In skeletal muscle the dystroglycan complex works as a transmembrane linkage between the extracellular matrix and the cytoskeleton. [alpha]-dystroglycan is extracellular and binds to merosin [alpha]-2 laminin in the basement membrane, while [beta]-dystroglycan is a transmembrane protein and binds to dystrophin, which is a large rod-like cytoskeletal protein, absent in Duchenne muscular dystrophy patients. Dystrophin binds to intracellular actin cables. In this way, the dystroglycan complex, which links the extracellular matrix to the intracellular actin cables, is thought to provide structural integrity in muscle tissues. The dystroglycan complex is also known to serve as an agrin receptor in muscle, where it may regulate agrin-induced acetylcholine receptor clustering at the neuromuscular junction. There is also evidence which suggests the function of dystroglycan as a part of the signal transduction pathway because it is shown that Grb2, a mediator of the Ras-related signal pathway, can interact with the cytoplasmic domain of dystroglycan.
Dystroglycan is widely distributed in non-muscle tissues as well as in muscle tissues. During epithelial morphogenesis of kidney, the dystroglycan complex is shown to act as a receptor for the basement membrane. Dystroglycan expression in Mus musculus brain and neural retina has also been reported. However, the physiological role of dystroglycan in non-muscle tissues remains unclear.
^Skynner MJ, Gangadharan U, Coulton GR, Mason RM, Nikitopoulou A, Brown SD, Blanco G (Jan 1995). "Genetic mapping of the mouse neuromuscular mutation kyphoscoliosis". Genomics. 25 (1): 207–13. doi:10.1016/0888-7543(95)80127-8. PMID7774920.
Ibraghimov-Beskrovnaya O, Milatovich A, Ozcelik T, Yang B, Koepnick K, Francke U, Campbell KP (Oct 1993). "Human dystroglycan: skeletal muscle cDNA, genomic structure, origin of tissue specific isoforms and chromosomal localization". Human Molecular Genetics. 2 (10): 1651–7. doi:10.1093/hmg/2.10.1651. PMID8268918.
Côté PD, Moukhles H, Lindenbaum M, Carbonetto S (Nov 1999). "Chimaeric mice deficient in dystroglycans develop muscular dystrophy and have disrupted myoneural synapses". Nature Genetics. 23 (3): 338–42. doi:10.1038/15519. PMID10610181. S2CID564897.
Rentschler S, Linn H, Deininger K, Bedford MT, Espanel X, Sudol M (Apr 1999). "The WW domain of dystrophin requires EF-hands region to interact with beta-dystroglycan". Biological Chemistry. 380 (4): 431–42. doi:10.1515/BC.1999.057. PMID10355629. S2CID24598356.
Tommasi di Vignano A, Di Zenzo G, Sudol M, Cesareni G, Dente L (Apr 2000). "Contribution of the different modules in the utrophin carboxy-terminal region to the formation and regulation of the DAP complex". FEBS Letters. 471 (2–3): 229–34. doi:10.1016/S0014-5793(00)01400-9. PMID10767429. S2CID21529759.
James M, Nuttall A, Ilsley JL, Ottersbach K, Tinsley JM, Sudol M, Winder SJ (May 2000). "Adhesion-dependent tyrosine phosphorylation of (beta)-dystroglycan regulates its interaction with utrophin". Journal of Cell Science. 113 ( Pt 10) (10): 1717–26. PMID10769203.
Russo K, Di Stasio E, Macchia G, Rosa G, Brancaccio A, Petrucci TC (Jul 2000). "Characterization of the beta-dystroglycan-growth factor receptor 2 (Grb2) interaction". Biochemical and Biophysical Research Communications. 274 (1): 93–8. doi:10.1006/bbrc.2000.3103. PMID10903901.