Enables protein C-terminus binding activity and ubiquitin-protein transferase activity. Involved in several processes, including regulation of postsynaptic neurotransmitter receptor internalization; regulation of protein catabolic process at postsynapse, modulating synaptic transmission; and response to denervation involved in regulation of muscle adaptation. Located in membrane raft and microvillus. Is active in glutamatergic synapse. Biomarker of muscular atrophy. Orthologous to human NEDD4 (NEDD4 E3 ubiquitin protein ligase). [provided by Alliance of Genome Resources, Apr 2022]