Nicotinic acetylcholine receptor subunit alpha-1 precursor (nAChR α1 or CHRNA1)

The nicotinic acetylcholine receptor subunit alpha-1 precursor is a protein subunit essential for the formation of the muscle-type nicotinic acetylcholine receptor (nAChR) at the neuromuscular junction. These receptors are pentameric ligand-gated ion channels composed, in the adult form, of two α1 subunits plus one each of β1, δ, and ε subunits. The alpha-1 subunit contains a large extracellular N-terminal domain for ligand binding, four transmembrane helices, an intracellular domain, and is characterized by the signature Cys-loop motif. Upon binding of acetylcholine or other agonists, the receptor undergoes a conformational change resulting in transient opening of the central ion channel, allowing passage of cations that lead to muscle depolarization and contraction[2][3][5][6]. This subunit is a key immunological and pharmacological target in various neuromuscular disorders, anesthesia (muscle relaxants), and research applications.

Other names

CHRNA1Neuromuscular nicotinic acetylcholine receptor alpha-1 subunitnAChR α1Muscle-type nAChR alpha-1 subunitAcetylcholine receptor alpha subunit (muscle)

Agonists (e.g., acetylcholine, nicotine) activate the receptor, allowing cation (sodium, potassium, calcium) permeability and depolarization at the neuromuscular junction[2][5]. Competitive antagonists (e.g., tubocurarine, pancuronium) block acetylcholine binding and inhibit muscle contraction[2][5]. Irreversible antagonists (e.g., α-bungarotoxin) bind strongly to the receptor and prevent activation[2][5].