PSD93 (DLG3) <table class="infobox infobox-protein">Gene Symbol </td>Official Name </td>Chromosomal Location </td>NCBI Gene ID </td>Ensembl ID </td>UniProt ID </td>
Overview PSD93 (Postsynaptic Density Protein of 93 kDa), encoded by the DLG3 gene, is a member of the membrane-associated guanylate kinase (MAGUK) family of scaffolding proteins. It plays a critical role in the organization of postsynaptic density complexes at excitatory synapses and has been implicated in synaptic plasticity, learning, and memory[@kim2004].
Protein Structure and Function
Domain Architecture PSD93 contains multiple protein-protein interaction domains:
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PSD93 (DLG3) <table class="infobox infobox-protein">Gene Symbol </td>Official Name </td>Chromosomal Location </td>NCBI Gene ID </td>Ensembl ID </td>UniProt ID </td>
Overview PSD93 (Postsynaptic Density Protein of 93 kDa), encoded by the DLG3 gene, is a member of the membrane-associated guanylate kinase (MAGUK) family of scaffolding proteins. It plays a critical role in the organization of postsynaptic density complexes at excitatory synapses and has been implicated in synaptic plasticity, learning, and memory[@kim2004].
Protein Structure and Function
Domain Architecture PSD93 contains multiple protein-protein interaction domains:
N-terminal region : Palmitoylation site for membrane targetingPDZ domains (3x): PDZ1-3 mediate interactions with [NMDA receptor](/entities/nmda-receptor) subunits (NR2A/B), AMPA receptor subunits, and other synaptic proteinsSH3 domain : Binds to proline-rich motifsGuanylate kinase (GK) domain : Catalytic domain with binding sites for GKAP/SAP90Synaptic Scaffolding PSD93 is a core component of the postsynaptic density (PSD) scaffold, forming a complex network with:
NMDA receptors (via PDZ domains)AMPA receptors (via PDZ interactions with GRIP/ABP)Kainate receptors Shank proteins (connecting to actin cytoskeleton)CRASH/Cortactin (actin remodeling)Role in Neurodegeneration
Alzheimer's Disease In AD, PSD93 alterations contribute to synaptic dysfunction through multiple mechanisms[@coley2020]:
NMDA receptor dysregulation : Altered PSD93 expression affects NMDAR localization and signalingAMPA receptor trafficking : Impaired AMPAR endocytosis and recyclingSynaptic plasticity deficits : Disrupted [LTP](/mechanisms/long-term-potentiation) and LTD mechanisms[Tau](/proteins/tau) pathology : PSD93 interacts with tau and may influence tau-mediated synaptic damage
Parkinson's Disease PSD93 has been implicated in PD through[@jiang2019]:
Dopaminergic synapse function : Role in maintaining dopaminergic synaptic architectureExcitotoxicity : Interaction with NMDA receptors may contribute to excitotoxic cell deathMitochondrial dysfunction : Possible connections to mitochondrial quality control pathwaysAmyotrophic Lateral Sclerosis In ALS, PSD93 may play a role in[@synaptic2020]:
Motor neuron synaptic stability : Disruption of neuromuscular junction integrityExcitotoxicity : Altered glutamate receptor dynamicsAxonal transport : Connections to cytoskeletal regulatory proteinsExpression Pattern
Brain Regions
Cerebral [cortex](/brain-regions/cortex) : High expression in layers II-III and V[Hippocampus](/brain-regions/hippocampus) : Strong expression in CA1 and dentate gyrusStriatum : Moderate expression in medium spiny [neurons](/entities/neurons)Cerebellum : Purkinje cell expressionBrainstem : Moderate expressionCell Type Specificity
Neurons : Primary expression in excitatory (glutamatergic) neurons[Astrocytes](/entities/astrocytes) : Low expression[Microglia](/cell-types/microglia-neuroinflammation) : Minimal expressionOligodendrocytes : Not expressedTherapeutic Implications
Drug Targets
PSD93-NMDAR interaction inhibitors : Potential neuroprotective agentsPSD93 stability modulators : Enhance synaptic resiliencePDZ domain modulators : Target protein-protein interactionsBiomarker Potential
CSF PSD93 levels : Possible biomarker for synaptic lossPostmortem brain tissue : Diagnostic aid for synaptic pathologyClinical Significance
Associated Conditions
X-linked mental retardation : DLG3 mutations associated with non-syndromic intellectual disability[@tarpey2004]Epilepsy : Altered PSD93 expression in epileptic tissueSchizophrenia : Reduced PSD93 in prefrontal cortexNeurodevelopmental disorders : Synaptic scaffolding abnormalitiesSee Also
External Links
[Ensembl: ENSG00000165646](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000165646)
[GeneCards: DLG3](https://www.genecards.org/cgi-bin/carddisp.pl?gene=DLG3)
PSD95 (DLG4) — Closely related MAGUK family member
DLG2 — Another PSD93 homolog
Shank3 — Postsynaptic scaffold interactor
GRIP1 — AMPA receptor interacting protein
NR2A (GRIN2A) — NMDA receptor subunit
NR2B (GRIN2B) — NMDA receptor subunit
References
[Kim & Sheng, PDZ domain proteins: Synaptic scaffolding (2004)](https://pubmed.ncbi.nlm.nih.gov/15536461/)
[Coley & Zull, Synaptic dysfunction in Alzheimer's disease (2020)](https://pubmed.ncbi.nlm.nih.gov/31774128/)
[Jiang & Uh, Postsynaptic density proteins in Parkinson's disease (2019)](https://pubmed.ncbi.nlm.nih.gov/31195089/)
[(2020), Synaptic alterations in ALS (2020)](https://pubmed.ncbi.nlm.nih.gov/32854767/)
[Tarpey et al, Mutations in DLG3 cause X-linked mental retardation (2004)](https://pubmed.ncbi.nlm.nih.gov/15536479/) Show full description