Acts upstream of or within binding activity of sperm to zona pellucida and flagellated sperm motility. Located in acrosomal vesicle; cell surface; and plasma membrane. Is expressed in several structures, including central nervous system; reproductive system; retina; spleen; and stomach. Orthologous to human LY6K (lymphocyte antigen 6 family member K). [provided by Alliance of Genome Resources, Apr 2022]