Non-alpha subunit of nicotinic acetylcholine receptor (nAChR) (PubMed:8581398, PubMed:20027209). Acts in cholinergic motoneurons to regulate presynaptic neurotransmitter release, thereby ensuring normal level of excitation of cholinergic motoneurons during locomotion (PubMed:20027209, PubMed:23658528, PubMed:27782882). 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. Specifically expressed in cholinergic ventral cord motoneurons of the VA, VB, DA and DB classes but not AS and VC classes. Expressed in PVQ and DVC neurons in the tail. Expressed from L1 larval stage through adults. Locomotion is slower. Moderately resistant to paralysis induced by acetylcholine esterase inhibitor aldicarb but sensitivity to acetylcholine agonist levamisole is normal. Reduced both cholinergic and GABAergic motoneuron activities characterized by a reduction in miniature postsynaptic currents in muscles. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily.