HTR3A
5-Hydroxytryptamine Receptor 3A
Gene Information Card
| Symbol | HTR3A |
|---|---|
| Full Name | 5-Hydroxytryptamine Receptor 3A |
| Gene Type | protein-coding |
| Chromosomal Location | 11q23.2 |
| NCBI Gene ID | 3359 ncbi.nlm.nih.gov/gene/3359 |
| Ensembl ID | ENSG00000166736 |
| UniProt ID | P46098 |
| OMIM ID | 182139 |
| HGNC ID | 5298 |
| Aliases | 5-HT3A, 5-HT3R, 5-HT3-1, HTR3 |
Description
HTR3A encodes subunit A of the 5-hydroxytryptamine receptor 3 (5-HT3), a ligand-gated ion channel that mediates fast excitatory neurotransmission in the central and peripheral nervous systems. The receptor is a pentameric complex; HTR3A is essential for channel function. It is involved in emesis, pain perception, anxiety, and gastrointestinal motility.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Irritable Bowel Syndrome (IBS) | Altered 5-HT3 receptor function affects gut motility and visceral hypersensitivity | ClinVar, OMIM |
| Chemotherapy-Induced Nausea and Vomiting | HTR3A variants influence response to 5-HT3 antagonists | ClinVar, NCBI |
| Schizophrenia | Genetic association studies link HTR3A polymorphisms to disease risk | OMIM, NCBI |
| Bipolar Disorder | HTR3A variants may contribute to mood regulation abnormalities | OMIM |
| Anxiety Disorders | Dysregulation of 5-HT3 signaling in limbic system | NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 0.8 | Low |
| Small Intestine | 12.5 | High |
| Stomach | 8.3 | Medium |
| Colon | 6.1 | Medium |
| Spleen | 0.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y | 0.5 | Neuroblastoma; low expression |
| Caco-2 | 9.8 | Colorectal adenocarcinoma; high expression |
| HEK293 | 0.1 | Embryonic kidney; very low |
| Jurkat | 0.0 | T-cell leukemia; not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.137C>T (p.Pro46Leu) | Missense | <0.01% | Reduced receptor function; associated with IBS |
| c.178G>A (p.Val60Ile) | Missense | 0.02% | Altered ligand binding; linked to nausea |
| c.1030G>A (p.Gly344Ser) | Missense | 0.005% | Impaired channel gating; reported in schizophrenia |
Mutation functional classification
Loss of Function (LOF)
p.Pro46Leu reduces channel conductance and surface expression.
Gain of Function (GOF)
No confirmed gain-of-function variants reported.
Dominant Negative (DN)
p.Gly344Ser may exert dominant-negative effects on pentamer assembly.
View complete mutation data：
Gene Ontology (GO)
| • serotonin receptor activity (GO:0004993) | • extracellular ligand-gated ion channel activity (GO:0005230) |
| • ion transport (GO:0006811) | • chemical synaptic transmission (GO:0007268) |
| • integral component of membrane (GO:0016021) | • neurotransmitter receptor activity (GO:0030594) |
Pathways
• Serotonergic synapse (KEGG: hsa04726)
• Neuroactive ligand-receptor interaction (KEGG: hsa04080)
• 5-HT3 receptor signaling (Reactome: R-HSA-975298)
Protein Summary
HTR3A encodes the A subunit of the 5-HT3 receptor, a pentameric ligand-gated ion channel selective for cations (Na+, K+, Ca2+). The protein contains four transmembrane domains and an extracellular N-terminal ligand-binding domain. Upon serotonin binding, the channel opens, causing rapid depolarization. HTR3A is the obligatory subunit; without it, functional 5-HT3 receptors cannot form.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HTR3A Knockout HEK293 Cell Line | EDJ-KQ2961 | Human | 3359 | Details Get a Quote |
| HTR3A Knockout HeLa Cell Line | EDJ-KQ53594 | Human | 3359 | Details Get a Quote |
| HTR3A Knockout A-549 Cell Line | EDJ-KQ62061 | Human | 3359 | Details Get a Quote |
| HTR3A Knockout HCT 116 Cell Line | EDJ-KQ70544 | Human | 3359 | Details Get a Quote |
