HTR3A

HTR3A is a gene that encodes the 5-HT3A subunit of the 5-HT3 receptor, a member of the superfamily of ligand-gated ion channels. This receptor is cation-selective and mediates neuronal depolarization and excitation within the central and peripheral nervous systems. The 5-HT3A subunit, along with other subunits, forms a functional 5-HT3 receptor.

Structure

The HTR3A gene is located on the long arm of chromosome 11 (11q23.1-q23.2). It spans approximately 9 kilobases and consists of 9 exons. The 5-HT3A subunit is composed of an extracellular N-terminal domain, four transmembrane domains (M1, M2, M3, M4), and a large intracellular loop between M3 and M4.

Function

The 5-HT3 receptor is a serotonin-gated ion channel, which when activated, leads to rapid depolarization of neurons. It is thought to play a role in the modulation of neurotransmitter release, the regulation of pain, and the induction of vomiting.

Clinical significance

Variations in the HTR3A gene have been associated with susceptibility to schizophrenia, depression, and anxiety disorders. In addition, the 5-HT3 receptor is a target for certain medications used to treat nausea and vomiting caused by cancer chemotherapy, radiation therapy, and surgery.

See also

• 5-HT3 receptor
• Serotonin
• Neurotransmitter