GRIK4
Glutamate Ionotropic Receptor Kainate Type Subunit 4
Gene Information Card
| Symbol | GRIK4 |
|---|---|
| Full Name | glutamate ionotropic receptor kainate type subunit 4 |
| Gene Type | protein-coding |
| Chromosomal Location | 11q22.3 |
| NCBI Gene ID | 2900 ncbi.nlm.nih.gov/gene/2900 |
| Ensembl ID | ENSG00000149403 |
| UniProt ID | Q16099 |
| OMIM ID | 600282 |
| HGNC ID | 4582 |
| Aliases | GluK4, KA1, GRIK |
Description
GRIK4 encodes a subunit of the kainate-type glutamate receptor, which is an ionotropic receptor mediating excitatory neurotransmission. The encoded protein (GluK4) forms functional heteromeric channels with other kainate receptor subunits and is involved in synaptic plasticity, learning, and memory. GRIK4 is expressed predominantly in the brain, with highest levels in the hippocampus, cortex, and cerebellum.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Schizophrenia | Genetic association; variants in GRIK4 may alter glutamatergic signaling and synaptic function, contributing to disease risk. | Multiple case-control studies; meta-analysis (PMID: 17903297) |
| Bipolar disorder | Association with GRIK4 polymorphisms; potential impact on glutamate receptor function and mood regulation. | GWAS and replication studies (PMID: 18470944) |
| Major depressive disorder | Variants in GRIK4 linked to treatment response and disease susceptibility. | Pharmacogenetic studies (PMID: 17632560) |
| Autism spectrum disorder | Rare variants in GRIK4 identified in some ASD cohorts; role in synaptic dysfunction. | Exome sequencing studies (PMID: 22495306) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain - hippocampus | 12.5 | High |
| Brain - cortex | 8.3 | Medium |
| Brain - cerebellum | 6.7 | Medium |
| Brain - amygdala | 5.1 | Low |
| Testis | 1.2 | Low |
| Other tissues | <1.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 4.8 | Moderate expression |
| U-87 MG (glioblastoma) | 2.3 | Low expression |
| HEK293 (embryonic kidney) | 0.5 | Very low/background |
| H4 (neuroglioma) | 3.1 | Low to moderate |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs1954787 (G>A) | SNP | 0.25 (global) | Intronic; associated with altered splicing and schizophrenia risk |
| rs2239023 (C>T) | missense | 0.02 (global) | p.Pro290Leu; may affect receptor trafficking |
| rs4935924 (A>G) | SNP | 0.35 (global) | Intronic; linked to bipolar disorder |
| c.1234C>T | nonsense | Rare | p.Arg412*; predicted loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift variants leading to truncated or absent GluK4 protein, reducing functional kainate receptor assembly.
Gain of Function (GOF)
Not well characterized; some missense variants may alter channel kinetics or desensitization.
Dominant Negative (DN)
Missense mutations that disrupt heteromeric receptor formation, potentially impairing normal subunit function.
View complete mutation data：
Gene Ontology (GO)
| • ionotropic glutamate receptor activity (GO:0004972) | • extracellular ligand-gated ion channel activity (GO:0005230) |
| • glutamate receptor signaling pathway (GO:0007215) | • ion transmembrane transport (GO:0034220) |
| • plasma membrane (GO:0005886) | • synapse (GO:0045202) |
| • excitatory postsynaptic potential (GO:0060079) |
Pathways
• KEGG: hsa04724 - Glutamatergic synapse
• Reactome: R-HSA-399719 - Trafficking of AMPA receptors
• Reactome: R-HSA-438066 - Unblocking of NMDA receptor
• glutamate binding and activation
• WikiPathways: WP474 - Glutamate receptor signaling
Protein Summary
The GluK4 protein (UniProt Q16099) is a 956-amino acid transmembrane subunit of kainate-type glutamate receptors. It contains an extracellular N-terminal domain, a ligand-binding domain, three transmembrane helices (M1, M3, M4), and a pore-forming loop (M2). GluK4 does not form functional homomeric channels but co-assembles with GluK1-3 subunits to form heteromeric receptors with distinct pharmacological and biophysical properties. It is highly expressed in the hippocampus and cortex, where it modulates synaptic transmission and plasticity. Post-translational modifications include N-glycosylation and phosphorylation, which regulate receptor trafficking and function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GRIK4 Knockout HEK293 Cell Line | EDJ-KQ4794 | Human | 2900 | Details Get a Quote |
| GRIK4 Knockout HeLa Cell Line | EDJ-KQ53427 | Human | 2900 | Details Get a Quote |
| GRIK4 Knockout A-549 Cell Line | EDJ-KQ61904 | Human | 2900 | Details Get a Quote |
| GRIK4 Knockout HCT 116 Cell Line | EDJ-KQ70384 | Human | 2900 | Details Get a Quote |
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