Neuronal acetylcholine receptor subunit alpha-9, also known as nAChRα9, is a protein that in humans is encoded by the CHRNA9gene.[1] The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
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.[1]
Selective block of α9α10 nicotinic acetylcholine receptors by the conotoxin RgIA has been shown to be analgesic in an animal model of nerve injury pain.[2]
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Lustig LR, Peng H (2003). "Chromosome location and characterization of the human nicotinic acetylcholine receptor subunit alpha (alpha) 9 (CHRNA9) gene". Cytogenet. Genome Res. 98 (2–3): 154–9. doi:10.1159/000069804. PMID12697997.
Valor LM, Castillo M, Ortiz JA, Criado M (2003). "Transcriptional regulation by activation and repression elements located at the 5'-noncoding region of the human alpha9 nicotinic receptor subunit gene". J. Biol. Chem. 278 (39): 37249–55. doi:10.1074/jbc.M307043200. PMID12860975.
Peng H, Ferris RL, Matthews T, et al. (2004). "Characterization of the human nicotinic acetylcholine receptor subunit alpha (alpha) 9 (CHRNA9) and alpha (alpha) 10 (CHRNA10) in lymphocytes". Life Sci. 76 (3): 263–80. doi:10.1016/j.lfs.2004.05.031. PMID15531379.
Hillier LW, Graves TA, Fulton RS, et al. (2005). "Generation and annotation of the DNA sequences of human chromosomes 2 and 4". Nature. 434 (7034): 724–31. doi:10.1038/nature03466. PMID15815621.
