Enables PDZ domain binding activity. Involved in several processes, including chemical synaptic transmission; nervous system development; and synapse organization. Acts upstream of or within glutamatergic neuron differentiation; limbic system development; and neuron projection development. Located in several cellular components, including cerebellar granule cell to Purkinje cell synapse; main axon; and presynaptic active zone membrane. Is integral component of membrane. Part of voltage-gated potassium channel complex. Is active in dendrite and excitatory synapse. Is expressed in central nervous system and neural retina. Used to study autism spectrum disorder and cortical dysplasia-focal epilepsy syndrome. Human ortholog(s) of this gene implicated in several diseases, including Pitt-Hopkins syndrome; autism spectrum disorder (multiple); communication disorder (multiple); cortical dysplasia-focal epilepsy syndrome; and social phobia. Orthologous to human CNTNAP2 (contactin associated protein 2). [provided by Alliance of Genome Resources, Apr 2022]