Non-alpha subunit of nicotinic acetylcholine receptor (nAChR) (PubMed:9606719, PubMed:20027209). Probably acts in cholinergic motoneurons to regulate presynaptic neurotransmitter release, thereby ensuring normal level of excitation of cholinergic motoneurons during locomotion (PubMed:20027209). Component of nicotinic acetylcholine receptor. In cholinergic motoneurons, composed of 2 non-alpha subunits acr-2 and acr-3, and 3 alpha subunits unc-38, unc-63 and acr-12. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily.