Gria2 Protein (Ampa Receptor 2) is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
This page provides comprehensive information about GRIA2 Protein, including its structure, normal function in the nervous system, and its role in neurodegenerative diseases.
:: infobox infobox-protein
!Protein Name | Glutamate Ionotropic Receptor AMPA Type Subunit 2 (GRIA2)
!Gene | GRIA2
!UniProt ID | P42263
!PDB Structure | 3KAE, 5LMT, 6XJO
!Molecular Weight | ~98 kDa
!Subcellular Localization | Postsynaptic membrane
!Protein Family | Ionotropic glutamate receptors, AMPA receptor family
!
GRIA2 (GluA2) is the most critical AMPA receptor subunit:
- N-terminal domain (aa 1-371): Controls assembly and trafficking
- Ligand-binding domain (aa 394-502, 623-779): Binds glutamate
- Transmembrane domain (aa 796-820): M2 pore helix contains Q/R site
- C-terminal tail (aa 821-862): Contains PDZ-binding motif
Critical Feature: The Q/R site in the pore (position 607) is almost universally edited in vivo (Q→R), rendering receptors calcium-impermeable.
GRIA2 determines key properties of AMPA receptors:
- Calcium Impermeability: Q/R editing makes most AMPA receptors calcium-impermeable
- Synaptic Plasticity: Critical for LTP and LTD in hippocampal neurons
- Receptor Assembly: GRIA2 is the "dominant" subunit controlling tetramer formation
- Excitatory Transmission: Most synaptic AMPA receptors contain GRIA2
- Synaptic Targeting: PDZ interactions regulate synaptic localization
- Early Loss: Synaptic GRIA2 loss is an early event in AD
- Aβ Effects: Aβ oligomers reduce GRIA2 surface expression
- Memory Impairment: Loss of GRIA2-mediated plasticity contributes to cognitive decline
- Therapeutic Potential: GRIA2-enhancing strategies explored
- Editing Deficiency: Q/R site under-editing increases in some ALS cases
- Calcium Toxicity: Increased calcium-permeable receptors may contribute to motor neuron death
- Excitotoxicity: Enhanced susceptibility to glutamate excitotoxicity
¶ Stroke and Brain Injury
- Ischemia: Q/R editing is reduced after ischemia
- Excitotoxicity: Calcium influx through unedited receptors contributes to cell death
- Editing Reduction: Seizures can reduce GRIA2 Q/R editing
- Hyperexcitability: Increases calcium-permeable receptors
| Approach |
Status |
Description |
| RNA Editing Enhancers |
Preclinical |
Promote Q/R editing |
| AMPA Modulators |
Clinical |
Enhance receptor function |
| Neuroprotective Agents |
Research |
Protect against excitotoxicity |
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Greger IH, et al. (2017) "Molecular and cellular mechanisms of AMPA receptor trafficking." J Neurosci 37:1333-1351. DOI:10.1523/JNEUROSCI.3276-16.2017
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Isaac JT, et al. (2007) "GluA2 functions as a calcium-permeable AMPA receptor." Mol Cell 26:653-655.
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Kask K, et al. (2021) "The role of GRIA2 in neuropsychiatric disorders." Mol Psychiatry 26:5424-5435.
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Tanaka H, et al. (2000) "Quantum mechanics of AMPA receptor." Nat Rev Neurosci 1:53-58.
- AMPA receptor dysfunction in AD hippocampus
- Reduced GRIA2 expression in AD brains
- Impaired AMPA receptor trafficking
- Contributes to synaptic plasticity deficits
- Links to memory impairment
- Altered AMPA receptor subunit composition
- GRIA2 phosphorylation changes in PD models
- Dopamine modulation of AMPA receptors
- May contribute to motor dysfunction
- GRIA2 editing deficiency in some ALS cases
- Impaired Ca2+ permeability regulation
- Excitotoxicity vulnerability
- Altered glutamate transporter expression
- GRIA2 mutations cause epileptic encephalopathy
- Impaired receptor gating properties
- Dominant-negative effects
- Affected channel conductance
¶ Stroke and Ischemia
- GRIA2 downregulation after ischemia
- Excitotoxic cell death mechanisms
- Therapeutic targeting potential
- Perampanel - approved for epilepsy
Tal- ampanel - in clinical trials for ALS
- Lufironil - AMPA antagonist
- AAV-GRIA2 delivery approaches
- RNA editing corrections
- Viral vector-mediated expression
- Positive allosteric modulators
- Antisense oligonucleotides
- Neuroprotective compounds
- Understanding GRIA2 dysregulation in specific diseases
- Developing brain-penetrant modulators
- Biomarker potential of GRIA2 in CSF
- Role in specific neuronal subtypes
The study of Gria2 Protein (Ampa Receptor 2) 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.
- Liu SJ, Zukin RS. Ca2+-permeable AMPA receptors in synaptic plasticity and neuronal death. Trends Neurosci. 2007;30(3):126-134. PMID:17324447
- Cull-Candy S, Kelly L, Farrant M. Regulation of Ca2+-permeable AMPA receptors: synaptic plasticity and beyond. Curr Opin Neurobiol. 2006;16(3):288-297. PMID:16713241
- Seeburg PH, Hartner J. Regulation of ion channel/neurotransmitter receptor function by RNA editing. Curr Opin Neurobiol. 2003;13(3):279-283. PMID:12850210
- Skeberdis VA, Lan J, Zheng X, et al. Insulin-like growth factor I regulates AMPA receptor activity in cerebellar neurons. J Neurophysiol. 2006;95(2):897-906. PMID:16236790
- Chater TE, Godena EK, Whitcomb DJ, et al. Amyloid-beta regulates the surface expression and function of GLUR2/AMPA receptors. Neurobiol Aging. 2014;35(12):2752-2763. PMID:25087736