Neuronal nicotinic acetylcholine receptor alpha4beta2 subtype (α4β2 nAChR)

The neuronal nicotinic acetylcholine receptor alpha4beta2 subtype (α4β2 nAChR) is a ligand-gated ion channel predominantly found in the brain, formed by the assembly of two types of subunits: α4 and β2[4][7][6]. It typically assembles as a pentamer in two main stoichiometries: (α4)2(β2)3 (high nicotine sensitivity) and (α4)3(β2)2 (lower sensitivity, higher Ca2+ permeability)[4][1]. When activated by acetylcholine or nicotine, the receptor opens a central pore permeable to cations (Na+, K+, and Ca2+), leading to rapid excitatory neurotransmission and the modulation of synaptic plasticity[2][4][6]. The α4β2 nAChR is the principal high-affinity binding site for nicotine in the brain, mediating the addictive properties of tobacco products[4]. This subtype plays a central role in cognitive function and neurological disorders, and is a major therapeutic target for smoking cessation drugs such as varenicline and cytisine, as well as a focus for potential treatments for Alzheimer's disease, schizophrenia, and certain forms of epilepsy[7][5][6]. Structural studies have resolved the architecture of the human α4β2 receptor, elucidating mechanisms of ligand binding, stoichiometry-dependent channel function, and drug interactions[6][1].

Other names

Alpha-4 beta-2 nicotinic receptorα4β2 receptorAlpha-4 beta-2 neuronal nicotinic acetylcholine receptorCHRNA4/CHRNB2 receptor

Agonists: bind to extracellular orthosteric site, causing channel opening and cation influx Partial agonists: induce partial channel opening and moderate desensitization (e.g., varenicline) Antagonists: block acetylcholine binding, inhibiting channel activation Positive allosteric modulators: enhance response to agonists by binding allosteric sites