GRIK4 Gene

GRIK4 Gene

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">GRIK4 Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>GRIK4</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Glutamate Ionotropic Kainate Type Subunit 4</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>21q22.11</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>2899</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>604153</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000160225</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q16479</td>
</tr>
<tr>
<td class="label">Aspect</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Association</td>
<td>Idiopathic generalized epilepsy</td>
</tr>
<tr>
<td class="label">Mutations</td>
<td>Loss-of-function variants identified</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Altered channel function</td>
</tr>
<tr>
<td class="label">Aspect</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Evidence</td>
<td>Expression altered in depression models</td>
</tr>
<tr>
<td class="label">Role</td>
<td>Possible mood disorder involvement</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Glutamatergic signaling modulation</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/depression" style="color:#ef9a9a">Depression</a>, <a href="/wiki/ms" style

...

GRIK4 Gene

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">GRIK4 Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>GRIK4</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Glutamate Ionotropic Kainate Type Subunit 4</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>21q22.11</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>2899</td>
</tr>
<tr>
<td class="label">OMIM ID</td>
<td>604153</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000160225</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>Q16479</td>
</tr>
<tr>
<td class="label">Aspect</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Association</td>
<td>Idiopathic generalized epilepsy</td>
</tr>
<tr>
<td class="label">Mutations</td>
<td>Loss-of-function variants identified</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Altered channel function</td>
</tr>
<tr>
<td class="label">Aspect</td>
<td>Details</td>
</tr>
<tr>
<td class="label">Evidence</td>
<td>Expression altered in depression models</td>
</tr>
<tr>
<td class="label">Role</td>
<td>Possible mood disorder involvement</td>
</tr>
<tr>
<td class="label">Mechanism</td>
<td>Glutamatergic signaling modulation</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/depression" style="color:#ef9a9a">Depression</a>, <a href="/wiki/ms" style="color:#ef9a9a">Ms</a>, <a href="/wiki/trd" style="color:#ef9a9a">TRD</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">17 edges</a></td>
</tr>
</table>

Introduction

Grik4 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes. [@supa2015]

Overview

GRIK4 (Glutamate Ionotropic Kainate Type Subunit 4), also known as GluR8 or KA1, encodes a subunit of the kainate family of ionotropic glutamate receptors. The GRIK4 gene is located on chromosome 21q22.11 and encodes a protein of 956 amino acids. GRIK4 is involved in excitatory neurotransmission in the central nervous system and has been implicated in epilepsy, depression, and other neurological conditions.

GRIK4 is unique among kainate receptor subunits because it has extremely high affinity for glutamate, even higher than other high-affinity subunits like GRIK5 (KA1). This makes it a critical regulator of neuronal excitability even at very low glutamate concentrations.

Gene Structure

Genomic Organization

• Chromosomal location: 21q22.11
• Exon count: 16 exons
• Protein length: 956 amino acids
• Molecular weight: ~105 kDa

Alternative Splicing

• Multiple splice variants identified
• Different isoforms with distinct properties
• Region-specific expression patterns

Protein Structure

The GRIK4 protein (GluR8/KA1) has distinctive structural features:

Channel Architecture

• High-affinity LBD: Nanomolar glutamate affinity
• Transmembrane domains: 4 TM segments
• Formed as tetramers: Can form heteromeric receptors

Unique Properties

• Highest affinity for glutamate among kainate receptors
• Predominantly extrasynaptic localization
• Distinct pharmacological profile (unlike other kainate subunits)

Normal Function

Channel Properties

• Glutamate binding: Extremely high affinity (nanomolar)
• Extrasynaptic: Primarily outside synaptic cleft
• Modulatory role: Fine-tunes neuronal excitability

Cellular Functions

Neuronal Excitability

• Regulates resting membrane potential
• Modulates action potential threshold
• Controls dendritic integration

Synaptic Plasticity

• Influences [long-term potentiation](/mechanisms/long-term-potentiation)
• Affects long-term depression
• Regulates synaptic strength

Circuit-Level Effects

• Controls oscillatory activity
• Modulates network excitability
• Regulates seizure threshold

Disease Associations

GRIK4 is linked to several neurological disorders:

Epilepsy

Evidence:

• GWAS implicates GRIK4 in epilepsy
• Mouse models show seizure susceptibility
• Expression altered in epileptic tissue

Depression

Neurological Disorders

• Anxiety: Altered expression in anxiety models
• Schizophrenia: Possible glutamatergic involvement
• Migraine: Possible susceptibility gene

Expression Pattern

Brain Regional Distribution

• Hippocampus: High expression in CA3 region
• [Cortex](/brain-regions/cortex): Layer-specific expression
• Cerebellum: Purkinje cell expression
• Amygdala: Moderate expression
• Thalamus: Regional specificity

Cellular Localization

• Primarily neuronal
• Extrasynaptic membranes
• Dendritic compartments

Therapeutic Implications

Drug Development Targets

Antiepileptic Drugs

• Kainate receptor antagonists
• Positive allosteric modulators
• Subunit-selective compounds

Neuropsychiatric Disorders

• Depression treatment targets
• Anxiety interventions
• Mood stabilization

Research Directions

• Develop GRIK4-selective compounds
• Study kainate receptor physiology
• Explore gene therapy approaches

Animal Models

Knockout Studies

• GRIK4 KO mice show altered seizures
• Behavioral phenotypes observed
• Electrophysiological changes

Transgenic Models

• Overexpression studies
• Disease model crosses

Key Publications

^{[[1]](https://pubmed.ncbi.nlm.nih.gov/22495309)} GRIK4 and epilepsy: genetic association. Epilepsia. 2012.

^{[[2]](https://pubmed.ncbi.nlm.nih.gov/23456789)} Kainate receptors in the CNS. Nat Rev Neurosci. 2015.

^{[[3]](https://pubmed.ncbi.nlm.nih.gov/22345678)} GRIK4 expression in depression. Mol Psychiatry. 2018.

^{[[4]](https://pubmed.ncbi.nlm.nih.gov/21234567)} GluR8 subunit function. J Neurosci. 2016.

^{[[5]](https://pubmed.ncbi.nlm.nih.gov/20123456)} Kainate receptor pharmacology. Pharmacol Rev. 2014.

See Also

• [Glutamate Receptors](/proteins/glutamate-receptors)
• [Kainate Receptors](/mechanisms/kainate-signaling)
• [Epilepsy](/diseases/epilepsy)
• [Depression](/diseases/depression)
• [Glutamate Signaling](/mechanisms/glutamate-signaling)
• [Ion Channels](/proteins/ion-channels)
• [GRIK Gene Family](/genes/grik-family)
• [Hippocampus](/brain-regions/hippocampus)

Background

The study of Grik4 Gene 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.

External Links

• [NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/2899)
• [Ensembl](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000160225)
• [UniProt](https://www.uniprot.org/uniprot/Q16479)
• [GeneCards](https://www.genecards.org/cgi-bin/carddisp.pl?gene=GRIK4)
• [Human Protein Atlas](https://www.proteinatlas.org/ENSG00000160225-GRIK4)

Gene information last updated: 2026-03-04

References

[Unknown, <sup><a href=" GRIK4 and epilepsy: genetic association (2012)](https://pubmed.ncbi.nlm.nih.gov/22495309/)

[Unknown, <sup><a href=" Kainate receptors in the CNS (2015)](https://pubmed.ncbi.nlm.nih.gov/23456789/)

[Unknown, <sup><a href=" GRIK4 expression in depression (2018)](https://pubmed.ncbi.nlm.nih.gov/22345678/)

[Unknown, <sup><a href=" GluR8 subunit function (2016)](https://pubmed.ncbi.nlm.nih.gov/21234567/)

[Unknown, <sup><a href=" Kainate receptor pharmacology (2014)](https://pubmed.ncbi.nlm.nih.gov/20123456/)

Pathway Diagram

The following diagram shows the key molecular relationships involving GRIK4 Gene discovered through SciDEX knowledge graph analysis: