Enables acetylcholine receptor inhibitor activity and ion channel inhibitor activity. Acts upstream of or within cholinergic synaptic transmission. Located in plasma membrane. Is expressed in several structures, including adrenal gland; alimentary system; central nervous system; eye; and respiratory system. Orthologous to several human genes including LYNX1-SLURP2 (LYNX1-SLURP2 readthrough). [provided by Alliance of Genome Resources, Apr 2022]