Dystroglycan

DAG1
Identifiers
Aliases	DAG1, 156DAG, A3a, AGRNR, DAG, MDDGC7, MDDGC9, MDDGA9, dystroglycan 1, LGMDR16
External IDs	OMIM: 128239; MGI: 101864; GeneCards: DAG1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1EG4, 2MK7
Gene location (Human) Chr. Chromosome 3 (human) Band 3p21.31 Start 49,468,703 bp End 49,535,618 bp
Gene location (Mouse) Chr. Chromosome 9 (mouse) Band 9 F1- F2|9 59.08 cM Start 108,081,833 bp End 108,141,157 bp
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in olfactory bulb trigeminal ganglion spinal ganglia glomerulus metanephric glomerulus pancreatic ductal cell placenta parotid gland nipple saphenous vein Top expressed in sciatic nerve renal corpuscle gastrula left lung left lung lobe decidua myocardium of ventricle right ventricle right lung Gonadal ridge More reference expression data BioGPS More reference expression data
Gene ontology Molecular function calcium ion binding protein binding virus receptor activity alpha-actinin binding vinculin binding actin binding tubulin binding structural constituent of muscle SH2 domain binding laminin binding laminin-1 binding dystroglycan binding Cellular component cell-cell junction nucleus synapse contractile ring filopodium node of Ranvier costamere lamellipodium dystroglycan complex membrane raft cell junction cytoskeleton membrane extracellular exosome basolateral plasma membrane postsynaptic membrane sarcolemma cytoplasm integral component of membrane focal adhesion plasma membrane dystrophin-associated glycoprotein complex nucleoplasm basement membrane cytosol extracellular space endoplasmic reticulum lumen Golgi lumen plasma membrane raft external side of plasma membrane nuclear periphery extracellular matrix extracellular region collagen-containing extracellular matrix glutamatergic synapse GABA-ergic synapse postsynaptic cytosol Biological process NLS-bearing protein import into nucleus extracellular matrix organization viral process regulation of embryonic cell shape response to peptide hormone regulation of epithelial to mesenchymal transition positive regulation of basement membrane assembly involved in embryonic body morphogenesis viral entry into host cell regulation of gastrulation negative regulation of cell migration Schwann cell development membrane protein ectodomain proteolysis calcium-dependent cell-matrix adhesion negative regulation of MAPK cascade nerve maturation microtubule anchoring commissural neuron axon guidance branching involved in salivary gland morphogenesis negative regulation of protein kinase B signaling morphogenesis of an epithelial sheet myelination in peripheral nervous system basement membrane organization epithelial tube branching involved in lung morphogenesis modulation by virus of host process protein O-linked glycosylation positive regulation of cell-matrix adhesion ageing Schwann cell differentiation response to denervation involved in regulation of muscle adaptation nerve development axon regeneration positive regulation of myelination skeletal muscle tissue regeneration positive regulation of protein kinase activity positive regulation of oligodendrocyte differentiation cellular response to mechanical stimulus cellular response to cholesterol angiogenesis involved in wound healing regulation of synapse organization regulation of neurotransmitter receptor localization to postsynaptic specialization membrane retrograde trans-synaptic signaling by trans-synaptic protein complex Sources:Amigo / QuickGO
Orthologs Databases NCBI: entry; OMA: entry Species Human Mouse Entrez 1605 13138 Ensembl ENSG00000173402 ENSMUSG00000039952 UniProt Q14118 Q62165 RefSeq (mRNA) NM_004393 NM_001165928 NM_001177634 NM_001177635 NM_001177636 NM_001177637 NM_001177638 NM_001177639 NM_001177640 NM_001177641 NM_001177642 NM_001177643 NM_001177644 NM_001276481 NM_001276482 NM_001276485 NM_001276486 NM_001276492 NM_001276493 NM_001276494 NM_010017 RefSeq (protein) NP_001159400 NP_001171105 NP_001171106 NP_001171107 NP_001171108 NP_001171109 NP_001171110 NP_001171111 NP_001171112 NP_001171113 NP_001171114 NP_001171115 NP_004384 NP_001263410 NP_001263411 NP_001263414 NP_001263415 NP_001263421 NP_001263422 NP_034147 Location (UCSC) Chr 3: 49.47 – 49.54 Mb Chr 9: 108.08 – 108.14 Mb PubMed search
Wikidata
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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.

Proper glycosylation of alpha-dystroglycan is essential for its function. In 2024, a high-throughput functional assay was developed to measure glycosylation levels and assess the functional impact of variants in the enzymes responsible for this process.

Expression

Dystroglycan is widely distributed in non-muscle tissues as well as in muscle tissues. During epithelial morphogenesis of the 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.

In December 2022, a review of the implications of abnormal dystroglycan expression and/or O-mannosylation on the pathogenesis of cancer was published.

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
• Dystrophin-associated protein complex
• Vitiligo

References

Further reading

External links

• Dystroglycans at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
• Overview at sdbonline.org