Nomenclature: α9

Family: Nicotinic acetylcholine receptors

Annotation status:  image of a green circle Annotated and expert reviewed. Please contact us if you can help with updates. 


Gene and Protein Information
Species TM AA Chromosomal Location Gene Symbol Gene Name Reference
Human 4 479 4p14 CHRNA9 cholinergic receptor, nicotinic, alpha 9 (neuronal) 5
Mouse 4 479 5 C3.1 Chrna9 cholinergic receptor, nicotinic, alpha polypeptide 9
Rat 4 479 14p11 Chrna9 cholinergic receptor, nicotinic, alpha 9 (neuronal) 1
Previous and Unofficial Names
cholinergic receptor, nicotinic, alpha polypeptide 9
acetylcholine receptor, nicotinic, alpha 9 (neuronal)
NACHR alpha 9
NACHR alpha-9
acetylcholine receptor alpha 9 subunit (nAChR)
cholinergic receptor, nicotinic, alpha 9
neuronal acetylcholine receptor subunit alpha-9
nicotinic acetylcholine receptor subunit alpha 9
nicotinic acetylcholine receptor subunit alpha-9
Database Links
ChEMBL Target
DrugBank Target
Ensembl Gene
Entrez Gene
GenitoUrinary Development Molecular Anatomy Project
Human Protein Reference Database
PharmGKB Gene
Protein Ontology (PRO)
RefSeq Nucleotide
RefSeq Protein
UniGene Hs.
Functional Characteristics
(α9)5: PCa/PNa = 9; α9α10: PCa/PNa = 9, Pf = 22%
Natural/Endogenous Ligands
Commonly used antagonists (Human)
(α9)5: α-bungarotoxin > methyllycaconitine > strychnine ~ tropisetron > tubocurarine; α9α10: α-bungarotoxin > tropisetron = strychnine > tubocurarine
Key to terms and symbols View all chemical structures Click column headers to sort
Ligand Sp. Action Affinity Units Reference
[3H]methyllycaconitine Hs Antagonist 8.12 pKd
pKd 8.12 (Kd 7.5x10-9 M) α9α10
[125I]α-bungarotoxin Hs Antagonist - -
muscarine Hs Antagonist - -
[3H]α-bungarotoxin Hs Antagonist - -
nicotine Hs Antagonist - -
α-bungarotoxin Hs Antagonist - -
α-conotoxin RgIA Hs Antagonist - -
strychnine Hs Antagonist - -
Tissue Distribution
Pituitary gland, keratinocytes
Species:  Human
Technique:  RT-PCR
References:  6
Olfactory epithelia
Species:  Mouse
Technique:  RT-PCR
References:  7
Dorsal root ganglion neurons
Species:  Rat
Technique:  In situ hybridisation, RT-PCR
References:  2
Pituitary gland, nasal epithelium, tongue, cochlea:-
mRNA has been detected by in situ hybridization in the pars tiberalis region of the pituitary gland, the nasal epithelium and tongue. In contrast, no evidence for expression in the central nervous system was detected. By means of of RT-PCR and, subsequently, by in situ hybridization, expression has been confirmed in the cochlea.
Species:  Rat
Technique:  In situ hybridisation, RT-PCR
References:  1,3
Physiological Consequences of Altering Gene Expression
Knockout mice have altered development and function of efferent innervation in the outer hair cells of the cochlear.
Species:  Mouse
Tissue:  Cochlear
Technique:  Knockout
References:  4,7


1. Elgoyhen AB, Johnson DS, Boulter J, Vetter DE, Heinemann S. (1994) Alpha 9: an acetylcholine receptor with novel pharmacological properties expressed in rat cochlear hair cells. Cell79 (4): 705-15. [PMID:7954834]

2. Lips KS, Pfeil U, Kummer W. (2002) Coexpression of alpha 9 and alpha 10 nicotinic acetylcholine receptors in rat dorsal root ganglion neurons. Neuroscience115 (1): 1-5. [PMID:12401316]

3. Morley BJ, Li HS, Hiel H, Drescher DG, Elgoyhen AB. (1998) Identification of the subunits of the nicotinic cholinergic receptors in the rat cochlea using RT-PCR and in situ hybridization. Brain Res. Mol. Brain Res.53 (1-2): 78-87. [PMID:9473597]

4. Murthy V, Taranda J, Elgoyhen AB, Vetter DE. (2009) Activity of nAChRs containing alpha9 subunits modulates synapse stabilization via bidirectional signaling programs. Dev Neurobiol69 (14): 931-49. [PMID:19790106]

5. Nguyen VT, Ndoye A, Grando SA. (2000) Novel human alpha9 acetylcholine receptor regulating keratinocyte adhesion is targeted by Pemphigus vulgaris autoimmunity. Am. J. Pathol.157 (4): 1377-91. [PMID:11021840]

6. Sgard F, Charpantier E, Bertrand S, Walker N, Caput D, Graham D, Bertrand D, Besnard F. (2002) A novel human nicotinic receptor subunit, alpha10, that confers functionality to the alpha9-subunit. Mol. Pharmacol.61 (1): 150-9. [PMID:11752216]

7. Vetter DE, Liberman MC, Mann J, Barhanin J, Boulter J, Brown MC, Saffiote-Kolman J, Heinemann SF, Elgoyhen AB. (1999) Role of alpha9 nicotinic ACh receptor subunits in the development and function of cochlear efferent innervation. Neuron23 (1): 93-103. [PMID:10402196]

To cite this database page, please use the following:

Cecilia Gotti, Michael. J. Marks, Neil S. Millar, Susan Wonnacott.
Nicotinic acetylcholine receptors: α9. Last modified on 14/03/2014. Accessed on 26/10/2014. IUPHAR database (IUPHAR-DB),

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