Alpha-3 beta-4 nicotinic receptor
Encyclopedia
The alpha-3 beta-4 nicotinic receptor, also known as the α3β4 receptor, is a type of nicotinic acetylcholine receptor
, consisting of α3
and β4
subunit
s. It is located in the brain
, where activation yields post-
and presynaptic excitation.
As with other nicotinic acetylcholine receptors, the α3β4 receptor is pentameric [(α3)m(β4)n where m + n = 5]. The exact subunit stoichiometry
is not known and it is possible that more than one functional α3β4 receptor assembles in vivo with varying subunit stoichiometries.
Nicotinic acetylcholine receptor
Nicotinic acetylcholine receptors, or nAChRs, are cholinergic receptors that form ligand-gated ion channels in the plasma membranes of certain neurons and on the postsynaptic side of the neuromuscular junction...
, consisting of α3
CHRNA3
Neuronal acetylcholine receptor subunit alpha-3 is a protein that in humans is encoded by the CHRNA3 gene.- Interactive pathway map :...
and β4
CHRNB4
Neuronal acetylcholine receptor subunit beta-4 is a protein that in humans is encoded by the CHRNB4 gene....
subunit
Protein subunit
In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...
s. It is located in the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
, where activation yields post-
Excitatory postsynaptic potential
In neuroscience, an excitatory postsynaptic potential is a temporary depolarization of postsynaptic membrane potential caused by the flow of positively charged ions into the postsynaptic cell as a result of opening of ligand-sensitive channels...
and presynaptic excitation.
As with other nicotinic acetylcholine receptors, the α3β4 receptor is pentameric [(α3)m(β4)n where m + n = 5]. The exact subunit stoichiometry
Stoichiometry
Stoichiometry is a branch of chemistry that deals with the relative quantities of reactants and products in chemical reactions. In a balanced chemical reaction, the relations among quantities of reactants and products typically form a ratio of whole numbers...
is not known and it is possible that more than one functional α3β4 receptor assembles in vivo with varying subunit stoichiometries.
Agonists
- AcetylcholineAcetylcholineThe chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...
- CarbacholCarbacholCarbachol , also known as carbamylcholine, is a drug that binds and activates the acetylcholine receptor. Thus it is classified as a cholinergic agonist. It is primarily used for various ophthalmic purposes, such as for treating glaucoma, or for use during ophthalmic surgery...
- CytisineCytisineCytisine, also known as baphitoxine and sophorine, is a pyridine-like alkaloid. In medical use, it improves the rate of smoking cessation. It is less effective but much cheaper than similar products. Its structure is similar to nicotine and has similar pharmacological effects...
- EpibatidineEpibatidineEpibatidine is an alkaloid found on the skin of the endangered Ecuadorian frog, Epipedobates tricolor. These frogs, like other poison dart frogs, are best known for their ability to sequester poisons from their prey and secrete these poisons onto their backs. Many Amerindian tribes would swipe the...
- NicotineNicotineNicotine is an alkaloid found in the nightshade family of plants that constitutes approximately 0.6–3.0% of the dry weight of tobacco, with biosynthesis taking place in the roots and accumulation occurring in the leaves...
Competitive
- DHβE
- compound 5, highly selective over a4b2 and a7
Noncompetitive
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- DextrorphanDextrorphanDextrorphan is a psychoactive drug of the morphinan chemical class which acts as an antitussive or cough suppressant and dissociative hallucinogen. It is the dextro-stereoisomer of racemorphan, the levo-half being levorphanol. Dextrorphan is produced by O-demethylation of dextromethorphan by CYP2D6...
- DextropropoxypheneDextropropoxypheneDextropropoxyphene, manufactured by Eli Lilly and Company, is an analgesic in the opioid category. It is intended to treat mild pain and has, in addition, anti-tussive and local anesthetic effects. It has been taken off the market in Europe and the US due to concerns of fatal overdoses and...
- HexamethoniumHexamethoniumHexamethonium is a ganglionic blocker, a nicotinic nACh receptor antagonist that acts in autonomic ganglia by binding mostly in or on the NN receptor, and not the acetylcholine binding site itself...
- ImipramineImipramineImipramine , also known as melipramine, is an antidepressant medication, a tricyclic antidepressant of the dibenzazepine group...
, K(d)Dissociation constantIn chemistry, biochemistry, and pharmacology, a dissociation constant is a specific type of equilibrium constant that measures the propensity of a larger object to separate reversibly into smaller components, as when a complex falls apart into its component molecules, or when a salt splits up into...
= 0.41 μM - LevacetylmethadolLevacetylmethadolLevacetylmethadol , levomethadyl acetate , Orlaam or levo-α-acetylmethadol is a synthetic opioid similar in structure to methadone. It has a long duration of action due to its active metabolites. It was approved in 1993 by the U.S. Food and Drug Administration for use in the treatment of opioid...
- MecamylamineMecamylamineMecamylamine is a nonselective and noncompetitive antagonist of the nicotinic acetylcholine receptors that was introduced in the 1950s as an antihypertensive agent.- Uses :...
- MethadoneMethadoneMethadone is a synthetic opioid, used medically as an analgesic and a maintenance anti-addictive for use in patients with opioid dependency. It was developed in Germany in 1937...
- TubocurarineTubocurarineTubocurarine is a neuromuscular-blocking drug or skeletal muscle relaxant in the category of non-depolarizing neuromuscular-blocking drugs, used adjunctively in anesthesia to provide skeletal muscle relaxation during surgery or mechanical ventilation...
- BupropionBupropionBupropion is an atypical antidepressant and smoking cessation aid. The drug is a non-tricyclic antidepressant and differs from most commonly prescribed antidepressants such as SSRIs, as its primary pharmacological action is thought to be norepinephrine-dopamine reuptake inhibition...
See also
- α4β2-Nicotinic receptorAlpha-4 beta-2 nicotinic receptorThe alpha-4 beta-2 nicotinic receptor, also known as the α4β2 receptor, is a type of nicotinic acetylcholine receptor, consisting of α4 and β2 subunits...
- α7-Nicotinic receptorAlpha-7 nicotinic receptorThe alpha-7 nicotinic receptor, also known as the α7 receptor, is a type of nicotinic acetylcholine receptor, consisting entirely of α7 subunits....