Alpha-3 beta-4 alpha-5 nicotinic acetylcholine receptor (α3β4α5 nAChR)

The alpha-3 beta-4 alpha-5 (α3β4α5) nicotinic acetylcholine receptor is a heteromeric ligand-gated ion channel composed of CHRNA3, CHRNB4, and CHRNA5 subunits (Gotti et al., 2009). It is predominantly localized in the autonomic ganglia and specific brain regions like the medial habenula and interpeduncular nucleus, where it regulates excitatory neurotransmission and the release of various neurotransmitters (Fowler et al., 2011). The α5 subunit is particularly significant as an accessory subunit that modulates the receptor's calcium permeability and desensitization kinetics. Genetic studies have identified the CHRNA5-A3-B4 gene cluster as a major susceptibility locus for nicotine dependence and smoking-related diseases, including lung cancer and COPD (Saccone et al., 2007). Pharmacologically, this receptor is targeted by smoking cessation therapies such as varenicline and cytisine, which act as partial agonists to reduce withdrawal symptoms. Experimental compounds like 18-methoxycoronaridine (18-MC) and AT-1001 target the α3β4 subtype to treat addiction by modulating the reward circuitry. However, therapeutic development is challenged by the receptor's role in the autonomic nervous system, where modulation can lead to side effects like hypotension and gastrointestinal motility issues.

Other names

CHRNA3/CHRNB4/CHRNA5 receptorNeuronal acetylcholine receptor subunit alpha-3/beta-4/alpha-5α3β4α5 nicotinic receptorCHRNA3-CHRNB4-CHRNA5 complexGanglionic-type nicotinic receptor

Agonist, Partial agonist, and Antagonist