Enables signaling receptor regulator activity. Involved in several processes, including long-term synaptic depression; protein localization to cell surface; and regulation of AMPA receptor activity. Acts upstream of or within several processes, including learning or memory; long-term synaptic potentiation; and synapse organization. Located in postsynaptic density membrane and synaptic vesicle membrane. Orthologous to human PRRT1 (proline rich transmembrane protein 1). [provided by Alliance of Genome Resources, Apr 2022]