Neuronal acetylcholine receptor subunit alpha-9, also known as nAChRα9, is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''CHRNA9''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
The protein encoded by this gene is a subunit of certain
nicotinic acetylcholine receptor
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral ner ...
s (nAchR).
α9 subunit-containing receptors are notably blocked by nicotine. The role of this antagonism in the effects of tobacco are unknown.
This gene is a member of the ligand-gated ionic channel family and nicotinic acetylcholine receptor gene superfamily. It encodes a plasma membrane protein that forms homo- or hetero-oligomeric divalent cation channels. This protein is involved in cochlea hair cell function and is expressed in both the inner and outer hair cells (OHCs) of the adult cochlea, although expression levels in adult inner hair cells is low. The activation of the alpha9/10 nAChR is via olivocochlear activity, represented by cholinergic efferent synaptic terminals originating from the superior olive region of the brainstem. The protein is additionally expressed in keratinocytes, the pituitary gland, B-cells and T-cells.
Selective block of α9α10 nicotinic acetylcholine receptors by the
conotoxin
A conotoxin is one of a group of neurotoxic peptides isolated from the venom of the marine cone snail, genus ''Conus''.
Conotoxins, which are peptides consisting of 10 to 30 amino acid residues, typically have one or more disulfide bonds. Cono ...
RgIA has been shown to be analgesic in an animal model of
nerve injury
Nerve injury is an injury to nervous tissue. There is no single classification system that can describe all the many variations of nerve injuries. In 1941, Seddon introduced a classification of nerve injuries based on three main types of nerve f ...
pain.
See also
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Nicotinic acetylcholine receptor
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral ner ...
References
Further reading
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External links
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Ion channels
Nicotinic acetylcholine receptors
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