CHRNA1 (Cholinergic Receptor Nicotinic Alpha Subunit 1) encodes the alpha-1 subunit of the nicotinic [acetylcholine](/entities/acetylcholine) receptor (nAChR), a ligand-gated ion channel critical for neuromuscular junction (NMJ) formation and function. Mutations in CHRNA1 cause congenital myasthenic syndromes and are implicated in various neurological conditions.
CHRNA1 is a human gene whose product cHRNA1 is a key component of the muscle-type nAChR, a pentameric ligand-gated ion channel[@changeux2020]:. Variants in CHRNA1 have been implicated in Neuromuscular Disorders, Neurodegeneration. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
Normal Function
CHRNA1 is a key component of the muscle-type nAChR, a pentameric ligand-gated ion channel[@changeux2020]:
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CHRNA1
CHRNA1 (Cholinergic Receptor Nicotinic Alpha Subunit 1) encodes the alpha-1 subunit of the nicotinic [acetylcholine](/entities/acetylcholine) receptor (nAChR), a ligand-gated ion channel critical for neuromuscular junction (NMJ) formation and function. Mutations in CHRNA1 cause congenital myasthenic syndromes and are implicated in various neurological conditions.
CHRNA1 is a human gene whose product cHRNA1 is a key component of the muscle-type nAChR, a pentameric ligand-gated ion channel[@changeux2020]:. Variants in CHRNA1 have been implicated in Neuromuscular Disorders, neurodegeneration. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
Normal Function
CHRNA1 is a key component of the muscle-type nAChR, a pentameric ligand-gated ion channel[@changeux2020]:
Neuromuscular Transmission
ACh Binding: The alpha-1 subunit contains the primary acetylcholine binding site
Ion Channel: Forms the cation-permeable pore for Na⁺ and K⁺ influx
Endplate Potential: Triggers muscle fiber depolarization at the NMJ
Receptor Structure
Pentameric Assembly: Typically (α1)₂β1δ1ε1 in adult receptors
Developmental Isoforms: Embryonic receptors contain γ instead of ε subunit
Fast Synaptic Transmission: Millisecond-scale channel opening for rapid signaling
Signaling at NMJ
Synaptic Differentiation: Essential for postsynaptic specialization
Rapsyn Clustering: Partners with rapsyn for receptor anchoring
Agrin-LRP4-MuSK: Downstream of the agrin signaling pathway
Disease Associations
Neuromuscular Disorders
Congenital Myasthenic Syndrome (CMS): Over 100 mutations in CHRNA1 cause CMS[@chao2021]
Myasthenia Gravis: Autoantibodies target nAChR including the alpha-1 subunit
Slow Channel Syndrome: Gain-of-function mutations cause prolonged channel opening
Neurodegeneration
ALS: Altered nAChR expression in motor [neurons](/entities/neurons)
[Alzheimer's Disease](/diseases/alzheimers-disease): Neuronal nAChRs (α4β2, α7) are affected; muscle nAChR changes less studied
[Engel AG, Ohno K, Sine SM, The spectrum of congenital myasthenic syndromes (2003)](https://pubmed.ncbi.nlm.nih.gov/14501051/)
[Changeux JP, The nicotinic acetylcholine receptor: the founding member of the family of Cys-loop ligand-gated ion channels (2020)](https://pubmed.ncbi.nlm.nih.gov/32780241/)
[Chao CC, Lee TH, Hsu SY, et al, Congenital myasthenic syndrome due to CHRNA1 mutations: phenotype and treatment response (2021)](https://pubmed.ncbi.nlm.nih.gov/34088873/)