AChRa3b4 | nicotinic acetylcholine receptor alpha 3 beta 4
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.
AChRα3β4: Background Information
The alpha-3 beta-4 nicotinic receptor, also known as the α3β4 receptor and the ganglion-type nicotinic receptor, is a type of nicotinic acetylcholine receptor, consisting of α3 and β4 subunits. In the peripheral nervous system (PNS), the most abundant subtypes are α3β2* and α3β4* and are prominently expressed by ganglionic neurons. Because the α3β4 AChR subtype is predominantly expressed in nociceptive DRG neurons, it has been suggested that this subtype may be involved in neuronal signalling of nociception and inflammation.
UniProt P32297, P30926
Brain, hippocampus, cerebellum, retina. (α3β4β2) nAChRs are present on glutamate axons innervating Stratum radiatum (SR) interneurons and possibly other interneurons. PNS: The α3β4 subtype is prominently expressed in a variety of PNS neurons including those of DRG, superior cervical ganglia, cardiac ganglia, and ganglia innervating the viscera. The α3 subunit is furthermore expressed in the adrenal gland and lymphoid tissue
Mediates effects of acetylcholine and nicotine in specific regions of the brain, retina and spinal cord, post- and presynaptic excitation
Sporadic amyotrophic lateral sclerosis, genetic variations in CHRNA3 (Neuronal acetylcholine receptor subunit alpha-3) have been associated with susceptibility to smoking-related behavioral traits and lung cancer, nicotine dependence
Neuronal AChR is composed of two different types of subunits: alpha and beta. Alpha-3 subunit can be combined to beta-2 or beta-4 to give rise to functional receptors (furthermore, the Alpha-3 subunit can form a neuronal nicotinic acetylcholine receptor complex with the AChR Alpha-5 subunit: Alpha-3, Alpha-5, Beta-2 or Alpha-3, Alpha-5, Beta-4)
RIC3, LYPD6, alpha-conotoxin ImI
Acetylcholine, nicotine, epibatidine, DHβE, mecamylamine, α-conotoxin, hexamethonium, A-867744, NS1738
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-3 (CHRNA3, Homo sapiens)
- Neuronal acetylcholine receptor subunit beta-4 (CHRNB4, Homo sapiens)
Data and Applications