Dystroglycan

Dystroglycan 1 (dystrophin-associated glycoprotein 1)
250px PDB rendering based on 1u2c.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1EG4, 2MK7
Identifiers
Symbols	DAG1 ; 156DAG; A3a; AGRNR; DAG; MDDGC7; MDDGC9
External IDs	OMIM: 128239 MGI: 101864 HomoloGene: 3234 GeneCards: DAG1 Gene
Gene ontology Molecular function • virus receptor activity • dystroglycan binding • actin binding • calcium ion binding • protein binding • structural constituent of muscle • tubulin binding • vinculin binding • protein complex binding • SH2 domain binding • laminin-1 binding • alpha-actinin binding Cellular component • extracellular region • basement membrane • extracellular space • nucleoplasm • cytoplasm • cytoskeleton • plasma membrane • cell-cell adherens junction • focal adhesion • cell outer membrane • dystrophin-associated glycoprotein complex • dystroglycan complex • integral component of membrane • basolateral plasma membrane • lamellipodium • filopodium • node of Ranvier • sarcolemma • costamere • membrane raft • postsynaptic membrane • extracellular exosome • contractile ring Biological process • morphogenesis of an epithelial sheet • membrane protein ectodomain proteolysis • NLS-bearing protein import into nucleus • cytoskeletal anchoring at plasma membrane • regulation of gastrulation • regulation of epithelial to mesenchymal transition • calcium-dependent cell-matrix adhesion • regulation of embryonic cell shape • modulation by virus of host morphology or physiology • nerve maturation • myelination in peripheral nervous system • extracellular matrix organization • negative regulation of cell migration • microtubule anchoring • negative regulation of MAPK cascade • response to peptide hormone • viral entry into host cell • negative regulation of protein kinase B signaling • epithelial tube branching involved in lung morphogenesis • branching involved in salivary gland morphogenesis • commissural neuron axon guidance • basement membrane organization • positive regulation of basement membrane assembly involved in embryonic body morphogenesis Sources: Amigo / QuickGO
RNA expression pattern
File:PBB GE DAG1 205417 s at tn.png
File:PBB GE DAG1 212128 s at tn.png
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	1605	13138
Ensembl	ENSG00000173402	ENSMUSG00000039952
UniProt	Q14118	Q62165
RefSeq (mRNA)	NM_001165928	NM_001276481
RefSeq (protein)	NP_001159400	NP_001263410
Location (UCSC)	Chr 3: 49.47 – 49.54 Mb	Chr 9: 108.2 – 108.26 Mb
PubMed search	[1]	[2]

Dystroglycan is a protein that in humans is encoded by the DAG1 gene.

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).

Function

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.

Expression

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 has remained unclear

Interactions

Dystroglycan has been shown to interact with FYN, C-src tyrosine kinase, Src, NCK1, Grb2, Caveolin 3 and SHC1.

See also

• Actin-binding protein
• Agrin

External links

• Dystroglycans at the US National Library of Medicine Medical Subject Headings (MeSH)
• Overview at sdbonline.org
• http://www.neuro.wustl.edu/neuromuscular/musdist/dag2.htm#ad