HTR3A gene

The HTR3A gene (HTR3A stands for: 5-hydroxytryptamine receptor 3A) is a protein-coding gene located on chromosome 11q23.2. Alternatively spliced transcript variants coding for different isoforms have been identified.

The HTR3A gene codes for a receptor protein that belongs to the superfamily of ligand-gated ion channel receptors. The receptor consists of four transmembrane domains that form an intrinsic cation-selective channel.

The HTR3A gene encodes subunit A of the type 3 receptor for 5-hydroxytryptamine (serotonin), a biogenic hormone that acts as a neurotransmitter, hormone and mitogen. The encoded receptor protein forms serotonin (5-hydroxytryptamine/5-HT3)-activated cation-selective channel complexes that elicit rapid, depolarizing responses in neurons upon activation. It appears that the heteromeric combination of A and B subunits is necessary to obtain the full functional properties of this receptor, as each subunit alone results in receptors with very low conductance and response amplitude.

Diseases associated with HTR3A include serotonin syndrome and irritable bowel syndrome.

To date, five human 5-HT3 receptor subtypes have been identified (5-HT3A-E).

1. Gu QY et al. (2015) Association of genetic polymorphisms in HTR3A and HTR3E with diarrhea predominant irritable bowel syndrome. Int J Clin Exp Med 8:4581-4585.
2. Suchanecka A et al. (2022) Serotonin Receptor HTR3A Gene Polymorphisms rs1985242 and rs1062613, E-Cigarette Use and Personality. Int J Environ Res Public Health 19:4746.