HTR3E Gene - 5-Hydroxytryptamine Receptor 3E | Function, Expression & Clinical Significance

HTR3E encodes the E subunit of the 5-hydroxytryptamine receptor 3 (5-HT3), a pentameric ligand-gated ion channel that mediates fast excitatory neurotransmission in response to serotonin. The 5-HT3E subunit can form functional homomeric channels or co-assemble with other 5-HT3 subunits (e.g., A, B, C, D) to modulate receptor properties such as conductance and pharmacology. Expression is predominantly in the gastrointestinal tract and central nervous system, with roles in emesis, pain, and mood regulation.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Serotonergic synapse (KEGG: hsa04726)

• Neuroactive ligand-receptor interaction (KEGG: hsa04080)

• 5-HT3 receptor signaling (Reactome: R-HSA-975298)

The 5-HT3E protein is a 438-amino acid subunit of the 5-HT3 receptor, a cation-selective ion channel. It contains four transmembrane domains (M1-M4), a large extracellular N-terminal ligand-binding domain, and a cytoplasmic loop between M3 and M4. The E subunit confers unique pharmacological properties, including reduced sensitivity to certain antagonists compared to the A subunit. Homomeric 5-HT3E channels exhibit small conductance and rapid desensitization.