GABRQ
Gamma-Aminobutyric Acid Type A Receptor Subunit Theta
Gene Information Card
| Symbol | GABRQ |
|---|---|
| Full Name | Gamma-aminobutyric acid type A receptor subunit theta |
| Gene Type | protein-coding |
| Chromosomal Location | Xq28 |
| NCBI Gene ID | 55879 ncbi.nlm.nih.gov/gene/55879 |
| Ensembl ID | ENSG00000147133 |
| UniProt ID | Q9UN88 |
| OMIM ID | 300349 |
| HGNC ID | 14463 |
| Aliases | GABA(A) receptor subunit theta, GABRQ_HUMAN |
Description
GABRQ encodes the theta (θ) subunit of the gamma-aminobutyric acid type A (GABA-A) receptor, a ligand-gated chloride ion channel that mediates inhibitory neurotransmission in the central nervous system. The theta subunit can assemble with other GABA-A subunits (e.g., alpha, beta, gamma) to form heteropentameric receptors with distinct pharmacological properties. GABRQ is located on the X chromosome and is expressed primarily in the brain, with highest levels in the amygdala and hippocampus.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Epilepsy | Altered GABA-A receptor function due to GABRQ variants may disrupt inhibitory signaling, contributing to seizure susceptibility. | ClinVar: pathogenic missense variants reported in patients with epilepsy. |
| Intellectual Disability | X-linked variants in GABRQ may impair synaptic inhibition, affecting cognitive development. | OMIM: 300349 - association with X-linked intellectual disability. |
| Anxiety Disorders | Dysregulation of GABAergic transmission involving theta subunit may modulate anxiety-related circuits. | NCBI Gene: expression in amygdala suggests role in fear and anxiety. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain (amygdala) | 12.5 | Medium |
| Brain (hippocampus) | 10.2 | Medium |
| Brain (cerebral cortex) | 8.7 | Low |
| Testis | 3.1 | Low |
| Adrenal gland | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 5.8 | Neuronal model |
| U-87 MG (glioblastoma) | 2.3 | Low expression |
| HEK 293 (embryonic kidney) | 0.5 | Non-neuronal control |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.100C>T (p.Arg34Cys) | Missense | Rare | ClinVar: likely pathogenic; associated with epilepsy |
| c.457G>A (p.Gly153Ser) | Missense | Rare | ClinVar: uncertain significance |
| c.784delC (p.Leu262TrpfsTer5) | Frameshift | Rare | Predicted loss-of-function; reported in intellectual disability |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense variants likely lead to truncated or absent theta subunit, reducing GABA-A receptor function.
Gain of Function (GOF)
Not well documented for GABRQ; gain-of-function may involve increased chloride conductance but no confirmed examples.
Dominant Negative (DN)
Missense variants (e.g., p.Arg34Cys) may disrupt subunit assembly, impairing receptor function in a dominant-negative manner.
View complete mutation data：
Gene Ontology (GO)
Pathways
• GABAergic synapse (KEGG: hsa04727)
• Neuroactive ligand-receptor interaction (KEGG: hsa04080)
Protein Summary
The GABA-A receptor theta subunit (UniProt Q9UN88) is a 432-amino acid protein with four transmembrane domains (M1-M4) and a large intracellular loop. It forms heteropentameric chloride channels that mediate fast inhibitory neurotransmission. The theta subunit is less abundant than other GABA-A subunits and may confer unique benzodiazepine sensitivity. Structural studies suggest it can replace gamma subunits in some receptor configurations.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GABRQ Knockout HEK293 Cell Line | EDJ-KQ13538 | Human | 55879 | Details Get a Quote |
| GABRQ Knockout HCT 116 Cell Line | EDJ-KQ43163 | Human | 55879 | Details Get a Quote |
| GABRQ Knockout HeLa Cell Line | EDJ-KQ43164 | Human | 55879 | Details Get a Quote |
| GABRQ Knockout A-549 Cell Line | EDJ-KQ65153 | Human | 55879 | Details Get a Quote |
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