Enables type 1 neuromedin U receptor binding activity and type 2 neuromedin U receptor binding activity. Involved in several processes, including energy homeostasis; negative regulation of digestive system process; and positive regulation of cell communication. Acts upstream of or within neuropeptide signaling pathway. Located in terminal bouton. Used to study obesity. Human ortholog(s) of this gene implicated in obesity. Orthologous to human NMU (neuromedin U). [provided by Alliance of Genome Resources, Apr 2022]