DLG3: Discs Large MAGUK Scaffold Protein 3
A scaffold protein involved in synaptic organization and X-linked intellectual disability.
Gene Information Card
| Symbol | DLG3 |
|---|---|
| Full Name | Discs Large MAGUK Scaffold Protein 3 |
| Gene Type | Protein coding |
| Chromosomal Location | Xq13.1 |
| NCBI Gene ID | 1741 ncbi.nlm.nih.gov/gene/1741 |
| Ensembl ID | ENSG00000082458 |
| UniProt ID | Q92796 |
| OMIM ID | 300189 |
| HGNC ID | 2901 |
| Aliases | SAP102, NE-DLG, PPP1R82 |
Description
DLG3 (Discs Large MAGUK Scaffold Protein 3) encodes a member of the membrane-associated guanylate kinase (MAGUK) family. The protein, also known as SAP102, is predominantly expressed in the brain and localizes to the postsynaptic density of excitatory synapses. It functions as a scaffold that clusters NMDA receptors and other signaling proteins, playing a critical role in synaptic plasticity and cognitive function. Mutations in DLG3 cause X-linked intellectual disability type 90 (XLID90).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| X-linked intellectual disability 90 (XLID90) | Loss-of-function mutations in DLG3 disrupt synaptic scaffolding and NMDA receptor clustering, impairing synaptic transmission and plasticity. | ClinVar, OMIM |
| Intellectual disability, X-linked, with or without seizures | Missense and truncating variants in DLG3 have been identified in families with non-syndromic intellectual disability and epilepsy. | ClinVar, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain (cerebral cortex) | 12.5 | High |
| Brain (hippocampus) | 11.8 | High |
| Brain (cerebellum) | 9.2 | Medium |
| Testis | 2.1 | Low |
| Heart | 0.8 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 14.3 | Neuronal model |
| U-87 MG (glioblastoma) | 8.7 | Glial model |
| HEK293 (embryonic kidney) | 0.5 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.109C>T (p.Arg37*) | Nonsense | Rare | Loss of function; truncation of SAP102 |
| c.497G>A (p.Arg166Gln) | Missense | Rare | Impaired PDZ domain binding |
| c.1285_1286del (p.Leu429fs) | Frameshift | Rare | Loss of function; premature termination |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and splice-site mutations that lead to truncated or absent SAP102 protein, causing X-linked intellectual disability.
Gain of Function (GOF)
Not reported for DLG3.
Dominant Negative (DN)
Not reported for DLG3.
View complete mutation data：
Gene Ontology (GO)
| • synaptic transmission | • postsynaptic density assembly |
| • NMDA receptor clustering | • protein homodimerization activity |
| • guanylate kinase activity | • PDZ domain binding |
Pathways
• NMDA receptor signaling
• Postsynaptic density organization
• MAGUK signaling
Protein Summary
The DLG3 protein (SAP102) is a 902-amino acid scaffold containing three PDZ domains, an SH3 domain, and a guanylate kinase (GK) domain. It binds directly to NMDA receptor subunits (e.g., GluN2B) and links them to intracellular signaling complexes. SAP102 is essential for proper synaptic maturation and plasticity. Loss of function leads to cognitive impairment.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| DLG3 Knockout HEK293 Cell Line | EDJ-KQ1387 | Human | 1741 | Details Get a Quote |
| DLG3 Knockout A-549 Cell Line | EDJ-KQ20904 | Human | 1741 | Details Get a Quote |
| DLG3 Knockout HCT 116 Cell Line | EDJ-KQ20905 | Human | 1741 | Details Get a Quote |
| DLG3 Knockout HeLa Cell Line | EDJ-KQ20906 | Human | 1741 | Details Get a Quote |
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