Enables protease binding activity. Involved in negative regulation of neuron apoptotic process. Acts upstream of or within several processes, including adult locomotory behavior; exploration behavior; and generation of neurons. Located in apical part of cell and dendrite. Is expressed in nervous system and retina. Human ortholog(s) of this gene implicated in schizophrenia. Orthologous to human CHL1 (cell adhesion molecule L1 like). [provided by Alliance of Genome Resources, Apr 2022]