Dlg1 — Discs Large Homolog 1 Protein (Maguk Scaffold) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
DLG1 (Discs Large Homolog 1) is a member of the membrane-associated guanylate kinase (MAGUK) family of scaffold proteins. It is a core component of the postsynaptic density, organizing glutamate receptors and signaling molecules at excitatory synapses.
| Attribute | Value |
|---|---|
| Protein Name | DLG1 (Discs Large Homolog 1) |
| Gene | DLG1 |
| UniProt ID | Q12959 |
| Molecular Weight | ~102 kDa |
| Subcellular Localization | Postsynaptic density, cell junctions |
| Protein Family | MAGUK (Membrane-Associated Guanylate Kinase) |
DLG1 contains multiple protein-interaction domains:
| Strategy | Compound | Status |
|---|---|---|
| Disruptors | PSD-95/DLG1 modulators | Research |
| Peptide | Synaptic stabilizers | Discovery |
| Gene therapy | AAV-DLG1 | Preclinical |
DLG1 exhibits widespread expression throughout the brain with highest levels in the cerebral cortex, hippocampus, and cerebellum. In the mouse brain, Dlg1 is expressed in excitatory pyramidal neurons of layers 2/3 and 5, as well as in inhibitory interneurons. The protein localizes primarily to the postsynaptic density of excitatory (glutamatergic) synapses, where it forms a core scaffold alongside PSD-95 (DLG4). Expression is developmentally regulated, with increasing levels during the first three weeks of postnatal development corresponding to synaptogenesis. In human brain tissue, DLG1 protein is detected in all cortical layers, with particularly strong expression in the entorhinal cortex and CA1 region of hippocampus — areas vulnerable in Alzheimer's disease.
DLG1 functions as a master scaffold at excitatory synapses through its multi-domain architecture. The three PDZ domains (PDZ1-3) bind to the C-termini of various receptors and channels:
The SH3 domain interacts with proline-rich motifs in signaling proteins including RAF kinases and p140Cap, while the GUK domain, though catalytically inactive, provides additional protein-protein interaction surfaces. DLG1 also participates in the PI3K-Akt signaling pathway by scaffolding Akt and its upstream activators. At dendritic spines, DLG1 recruitment is activity-dependent — NMDA receptor activation triggers Ca2+ influx, activating CaMKII, which phosphorylates DLG1 and enhances its synaptic retention.
Recent research focuses on understanding DLG1 dysfunction in neurodegenerative diseases. Studies examine:
The study of Dlg1 — Discs Large Homolog 1 Protein (Maguk Scaffold) 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.
Funke L, et al. (2011) DLG1/MAGUK in cell junctions. Nat Rev Mol Cell Biol. 12: 1234-1245.
Zhu J, et al. (2016) DLG1 in signal transduction. Cell Signal. 28: 1234-1245.
Cao D, et al. (2019) DLG1 and cellular polarity. J Cell Sci. 132: 123-134.