CHRNA2 Gene - Cholinergic Receptor Nicotinic Alpha 2 Subunit | NCBI, UniProt, OMIM

CHRNA2 encodes the alpha-2 subunit of neuronal nicotinic acetylcholine receptors (nAChRs). These receptors are pentameric ligand-gated ion channels that mediate fast synaptic transmission in the central and peripheral nervous systems. The alpha-2 subunit combines with beta subunits to form functional receptors that respond to acetylcholine and nicotine. CHRNA2 is primarily expressed in the brain, particularly in the cerebral cortex, hippocampus, and thalamus. Mutations in CHRNA2 are associated with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and other neuropsychiatric conditions.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Nicotinic acetylcholine receptor signaling pathway (Reactome: R-HSA-629587)

• Neurotransmitter receptor binding and downstream transmission in the postsynaptic cell (Reactome: R-HSA-112314)

• Acetylcholine binding and channel opening (Reactome: R-HSA-629594)

The CHRNA2 protein (UniProt Q15822) is a 529-amino acid integral membrane protein with four transmembrane domains (M1-M4). It contains a large extracellular N-terminal domain that binds acetylcholine and nicotine, and a cytoplasmic loop between M3 and M4 that modulates receptor trafficking and function. The alpha-2 subunit assembles with beta subunits (e.g., beta-2, beta-4) to form functional heteropentameric channels. These channels are permeable to Na+, K+, and Ca2+ ions and mediate fast excitatory neurotransmission. Mutations in CHRNA2 alter channel properties and are linked to epilepsy.