GRIA2 Protein (AMPA Receptor 2)

GRIA2 Protein (AMPA Receptor Subunit 2)

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">GRIA2 Protein (AMPA Receptor 2)</th>
</tr>
<tr>
<td class="label">Approach</td>
<td>Status</td>
</tr>
<tr>
<td class="label">RNA Editing Enhancers</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">AMPA Modulators</td>
<td>Clinical</td>
</tr>
<tr>
<td class="label">Neuroprotective Agents</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/cardiovascular" style="color:#ef9a9a">Cardiovascular</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">53 edges</a></td>
</tr>
</table>

Introduction

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.

Overview

This page provides comprehensive information about GRIA2 Protein, including its structure, normal function in the nervous system, and its role in neurodegenerative diseases. [@cullcandy2006]

...

GRIA2 Protein (AMPA Receptor Subunit 2)

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">GRIA2 Protein (AMPA Receptor 2)</th>
</tr>
<tr>
<td class="label">Approach</td>
<td>Status</td>
</tr>
<tr>
<td class="label">RNA Editing Enhancers</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">AMPA Modulators</td>
<td>Clinical</td>
</tr>
<tr>
<td class="label">Neuroprotective Agents</td>
<td>Research</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/cardiovascular" style="color:#ef9a9a">Cardiovascular</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">53 edges</a></td>
</tr>
</table>

Introduction

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.

Overview

This page provides comprehensive information about GRIA2 Protein, including its structure, normal function in the nervous system, and its role in neurodegenerative diseases. [@cullcandy2006]

:: infobox infobox-protein [@seeburg2003]
!Protein Name | Glutamate Ionotropic Receptor AMPA Type Subunit 2 (GRIA2) [@skeberdis2006]
!Gene | [GRIA2](/proteins/gria2-protein) [@chater2014]
!UniProt ID | [P42263](https://www.uniprot.org/uniprot/P42263)
!PDB Structure | 3KAE, 5LMT, 6XJO
!Molecular Weight | ~98 kDa
!Subcellular Localization | Postsynaptic membrane
!Protein Family | Ionotropic glutamate receptors, AMPA receptor family
!

Structure

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.

Normal Function

GRIA2 determines key properties of AMPA receptors:

Calcium Impermeability: Q/R editing makes most AMPA receptors calcium-impermeable

Synaptic Plasticity: Critical for [LTP](/mechanisms/long-term-potentiation) and LTD in hippocampal [neurons](/entities/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

Role in Disease

Alzheimer's Disease

• Early Loss: Synaptic GRIA2 loss is an early event in AD
• [Aβ](/proteins/amyloid-beta) Effects: [Aβ](/proteins/amyloid-beta) oligomers reduce GRIA2 surface expression
• Memory Impairment: Loss of GRIA2-mediated plasticity contributes to cognitive decline
• Therapeutic Potential: GRIA2-enhancing strategies explored

Amyotrophic Lateral Sclerosis

• 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

Epilepsy

• Editing Reduction: Seizures can reduce GRIA2 Q/R editing
• Hyperexcitability: Increases calcium-permeable receptors

Therapeutic Targeting

Key Publications

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](https://doi.org/10.1523/JNEUROSCI.3276-16.2017)

Isaac JT, et al. (2007) "GluA2 functions as a calcium-permeable AMPA receptor." Mol Cell 26:653-655.

Kask K, et al. (2021) "The role of GRIA2 in neuropsychiatric disorders." Mol Psychiatry 26:5424-5435.

Tanaka H, et al. (2000) "Quantum mechanics of AMPA receptor." Nat Rev Neurosci 1:53-58.

Disease Associations

Alzheimer's Disease

• AMPA receptor dysfunction in AD [hippocampus](/brain-regions/hippocampus)
• Reduced GRIA2 expression in AD brains
• Impaired AMPA receptor trafficking
• Contributes to synaptic plasticity deficits
• Links to memory impairment

Parkinson's Disease

• Altered AMPA receptor subunit composition
• GRIA2 phosphorylation changes in PD models
• Dopamine modulation of AMPA receptors
• May contribute to motor dysfunction

Amyotrophic Lateral Sclerosis (ALS)

• GRIA2 editing deficiency in some ALS cases
• Impaired Ca2+ permeability regulation
• Excitotoxicity vulnerability
• Altered glutamate transporter expression

Epilepsy

• 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

Therapeutic Approaches

AMPA Receptor Modulators

• Perampanel - approved for epilepsy

Tal- ampanel - in clinical trials for ALS

• Lufironil - AMPA antagonist

Gene Therapy

• AAV-GRIA2 delivery approaches
• RNA editing corrections
• Viral vector-mediated expression

Small Molecule Approaches

• Positive allosteric modulators
• Antisense oligonucleotides
• Neuroprotective compounds

Research Directions

• Understanding GRIA2 dysregulation in specific diseases
• Developing brain-penetrant modulators
• Biomarker potential of GRIA2 in CSF
• Role in specific neuronal subtypes

See Also

• [AMPA Receptors](/proteins/ampa-receptors)
• [Glutamate Receptors](/glutamate-receptors-in-neuronal-function)
• [GRIA1](/proteins/gria1-protein)
• [GRIA3](/genes/gria3)
• [GRIA4](/proteins/gria4)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Epilepsy](/diseases/epilepsy)
• [Synaptic Transmission](/mechanisms/synaptic-dysfunction-pathway)

External Links

• [UniProt: P42262](https://www.uniprot.org/uniprot/P42262)
• [NCBI Gene: 2891](https://www.ncbi.nlm.nih.gov/gene/2891)
• [Wikipedia: AMPA receptor](https://en.wikipedia.org/wiki/AMPA_receptor)
• [Human Protein Atlas](https://www.proteinatlas.org/ENSG00000130158-GRIA2)

Background

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.

References

[Liu SJ, Zukin RS, Ca2+-permeable AMPA receptors in synaptic plasticity and neuronal death (2007)](https://pubmed.ncbi.nlm.nih.gov/17324447/)

[Cull-Candy S, Kelly L, Farrant M, Regulation of Ca2+-permeable AMPA receptors: synaptic plasticity and beyond (2006)](https://pubmed.ncbi.nlm.nih.gov/16713241/)

[Seeburg PH, Hartner J, Regulation of ion channel/neurotransmitter receptor function by RNA editing (2003)](https://pubmed.ncbi.nlm.nih.gov/12850210/)

[Skeberdis VA, Lan J, Zheng X, et al, Insulin-like growth factor I regulates AMPA receptor activity in cerebellar neurons (2006)](https://pubmed.ncbi.nlm.nih.gov/16236790/)

[Chater TE, Godena EK, Whitcomb DJ, et al, Amyloid-beta regulates the surface expression and function of GLUR2/AMPA receptors (2014)](https://pubmed.ncbi.nlm.nih.gov/25087736/)