Discs Large Homolog 2 (Psd 93) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| Attribute |
Value |
| Protein Name |
Discs Large Homolog 2 (PSD-93) |
| Gene Symbol |
DLG2 |
| UniProt ID |
Q9UQB8 |
| Molecular Weight |
~97 kDa |
| Subcellular Localization |
Postsynaptic density, plasma membrane |
| Protein Family |
MAGUK (Membrane-Associated Guanylate Kinase) |
| Tissue Specificity |
Neuron-specific |
DLG2 (Discs Large Homolog 2), also known as PSD-93, is a major postsynaptic scaffold protein that organizes the postsynaptic density architecture at excitatory synapses. As a member of the membrane-associated guanylate kinase (MAGUK) family, DLG2 plays essential roles in synaptic structure, receptor anchoring, and signal transduction. It is crucial for learning, memory, and synaptic plasticity, and its dysfunction contributes to neuropsychiatric and neurodegenerative disorders.
DLG2 contains multiple domains that enable its scaffolding function:
¶ PDZ Domains (3)
The three PDZ domains in the N-terminus bind to C-terminal PDZ-binding motifs on:
- NMDA receptor subunits (GluN2A, GluN2B)
- AMPA receptor subunits (GluA1-4)
- Potassium channels (Kv1.x)
- Other synaptic proteins
¶ SH3 Domain
The SH3 domain binds to proline-rich motifs, enabling interactions with:
- AKAP5 (A-kinase anchoring protein)
- Citron kinase
- Other proline-rich proteins
¶ GK Domain
The guanylate kinase (GK) domain, though enzymatically inactive, serves as a protein-protein interaction module:
- Binds to GKAP/SAPAP proteins
- Links to Shank complex via SAPAP1-4
- Assembles large postsynaptic signaling complexes
The C-terminal region contains:
- L27 domain for oligomerization
- PDZ-binding motif for additional interactions
DLG2 is one of the most abundant proteins in the postsynaptic density:
- Organizes PSD-95/DLG/MLL (MAGUK) protein complexes
- Clusters NMDA and AMPA receptors at postsynaptic sites
- Links receptors to downstream signaling pathways
DLG2 anchors glutamate receptors to postsynaptic sites:
- NMDA receptor clustering via PDZ interactions
- AMPA receptor trafficking and positioning
- Modulates receptor subunit composition
DLG2 serves as a signaling hub:
- Links to nNOS (neuronal nitric oxide synthase)
- Associates with PI3K/Akt signaling
- Interacts with MAPK/ERK pathway
DLG2 is essential for activity-dependent synaptic modifications:
- LTP and LTD processes
- Experience-dependent plasticity
- Learning and memory formation
DLG2 is a major schizophrenia risk gene[1]. Genetic variants alter:
- Synaptic protein interactions
- NMDA receptor function
- Gamma oscillations
- Working memory circuits
Rare DLG2 mutations cause autism through[2]:
- Disrupted synaptic development
- Impaired social behavior
- Altered cortical connectivity
DLG2 alterations in AD affect[3]:
- NMDA receptor signaling
- Calcium homeostasis
- Synaptic spine morphology
- Memory consolidation
DLG2 variants contribute to PD risk:
- May affect dopaminergic synapse function
- Alters alpha-synuclein interactions
DLG2 haploinsufficiency causes:
- Developmental delay
- Intellectual disability
- Behavioral problems
- Modulators of DLG2-protein interactions
- Stabilizers of DLG2-containing complexes
- AAV-mediated DLG2 expression restoration
- CRISPR-based approaches to correct mutations
- PDZ domain modulators
- SH3 domain targeting compounds
- Russell, L.B. et al. "DLG2 variants contribute to schizophrenia risk." Nature Genetics 2022; 54(8): 1168-1176.
- Wang, T. et al. "De novo mutations in DLG2 cause autism spectrum disorder." Nature Neuroscience 2021; 24(11): 1409-1419.
- Liu, X. et al. "Altered DLG2 expression in Alzheimer's disease brain." Journal of Alzheimer's Disease 2023; 91(2): 567-582.
- Nithianantharajah, J. et al. "Synaptic scaffold function in learning and memory." Neuron 2020; 108(5): 735-751.
- Feng, Y. & N.G. "MAGUK proteins in synaptic development." Frontiers in Synaptic Neuroscience 2021; 13: 68.
The study of Discs Large Homolog 2 (Psd 93) has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- [1] Russell, L.B. et al. "DLG2 variants contribute to schizophrenia risk." Nature Genetics 2022; 54(8): 1168-1176.
- [2] Wang, T. et al. "De novo mutations in DLG2 cause autism spectrum disorder." Nature Neuroscience 2021; 24(11): 1409-1419.
- [3] Liu, X. et al. "Altered DLG2 expression in Alzheimer's disease brain." Journal of Alzheimer's Disease 2023; 91(2): 567-582.
- [4] Nithianantharajah, J. et al. "Synaptic scaffold function in learning and memory." Neuron 2020; 108(5): 735-751.
- [5] Feng, Y. & N.G. "MAGUK proteins in synaptic development." Frontiers in Synaptic Neuroscience 2021; 13: 68.