Enables protein domain specific binding activity. A structural constituent of postsynaptic density. Involved in aggresome assembly; protein localization to synapse; and regulation of proteasomal protein catabolic process. Located in postsynaptic density and postsynaptic membrane. Is active in glutamatergic synapse and postsynaptic density, intracellular component. Orthologous to human DLGAP1 (DLG associated protein 1). [provided by Alliance of Genome Resources, Apr 2022]