Predicted to enable G protein-coupled acetylcholine receptor activity. Predicted to be involved in G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger; adenylate cyclase-inhibiting G protein-coupled acetylcholine receptor signaling pathway; and chemical synaptic transmission. Predicted to act upstream of or within G protein-coupled receptor signaling pathway. Predicted to be located in postsynaptic membrane. Predicted to be active in dendrite; plasma membrane; and synapse. Is expressed in eye. Human ortholog(s) of this gene implicated in Lambert-Eaton myasthenic syndrome; asthma; and myasthenia gravis. Orthologous to human CHRM1 (cholinergic receptor muscarinic 1).