AChRa4b2 | nicotinic acetylcholine receptor alpha 4 beta 2
The family has been devided into nicotinic acetylcholine receptors (ionotropic channels) and muscarinic acetylcholine receptors (metabotropic G-protein coupled receptors). Both subgroups are sensitive to acetylcholine.
Nicotinic acetylcholine receptors: As typical cys-loop receptors, acetylcholine receptor subunits contain four transmembrane spanning domains TM1-TM4. Five subunits form a pore, homomeric and heteromeric combinations are possible.17 vertebrate subunits have been identified: α genes: CHRNA1 - CHRNA10; β genes: CHRNB1 . CHRNB4, as well as CHRND (delta), CHRNE (epsilon), CHRNG (gamma)
Muscarinic acetylcholine receptors: 5 receptors have been described (M1 - M5), encoded by the 5 genes CHRM1 - CHRM5. These proteins contain seven transmembrane regions and do not form homo or heteromers.
AChRα4β2: Background Information
The alpha-4 beta-2 nicotinic receptor, also known as the α4β2 receptor, is a type of nicotinic acetylcholine receptor implicated in learning. Among the nicotinic receptor subtypes, nicotine has the highest binding affinity at the α4β2 receptor (ki=1 nM), which is also the primary biological target that mediates nicotine's addictive properties.
UniProt P43681, P17787
Its activation yields post- and presynaptic excitation, mainly by increased Na+ and K+ permeability. Stimulation of this receptor subtype is also associated with growth hormone secretion.
Epilepsy, nocturnal frontal lobe, 1 (ENFL1), paroxysmal kinesogenic dyskinesia
The Alpha-4 subunit can be combined to beta-2 or beta-4 to give rise to functional receptors, complexes with beta-2 may be heteropentamers
RIC3, LYPD6, the heteropentamer alpha-4-beta-2 interacts with alpha-conotoxins PnIA, GID and MII
Nicotine, acetylcholine, α-Conotoxin, Isoflurane
Patch Clamp: whole cell, room temperature
Reviews and Links
- Mammalian Nicotinic Acetylcholine Receptors: From Structure to Function; Physiol Rev 89: 73–120, 2009; doi:10.1152/physrev.00015.2008, Albuquergue et al;
Transporter classification database:
- Neuronal acetylcholine receptor subunit alpha-4 (CHRNA4, Homo sapiens)
- Neuronal acetylcholine receptor subunit beta-2 (CHRNB2, Homo sapiens)