Enables kinesin binding activity. A structural constituent of postsynaptic density. Involved in several processes, including nerve growth factor signaling pathway; regulation of neurotransmitter receptor localization to postsynaptic specialization membrane; and regulation of synaptic membrane adhesion. Located in several cellular components, including late endosome; perinuclear region of cytoplasm; and slit diaphragm. Part of protein-containing complex. Is active in GABA-ergic synapse; glutamatergic synapse; and postsynaptic density. Is extrinsic component of postsynaptic membrane. Human ortholog(s) of this gene implicated in nephrotic syndrome type 15. Orthologous to human MAGI2 (membrane associated guanylate kinase, WW and PDZ domain containing 2). [provided by Alliance of Genome Resources, Apr 2022]