GRIK4 Gene

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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

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

Mermaid diagram (expand to render)

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.

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

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

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

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

[Unknown, <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:

Mermaid diagram (expand to render)

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GRIK4 Gene

GRIK4 Gene

GRIK4 Gene

Introduction

Overview

Gene Structure

Genomic Organization

Alternative Splicing

Protein Structure

Channel Architecture

Unique Properties

Normal Function

Channel Properties

Cellular Functions

Neuronal Excitability

Synaptic Plasticity

Circuit-Level Effects

Disease Associations

Epilepsy

Depression

Neurological Disorders

Expression Pattern

Brain Regional Distribution

Cellular Localization

Therapeutic Implications

Drug Development Targets

Antiepileptic Drugs

Neuropsychiatric Disorders

Research Directions

Animal Models

Knockout Studies

Transgenic Models

Key Publications

See Also

Background

External Links

References

Pathway Diagram