Enables neuropeptide receptor activity. Involved in neuropeptide signaling pathway. Located in membrane. Is expressed in adult head; embryonic abdominal segment; larval central nervous system; larval insulin secreting cell of pars intercerebralis; and ventral midline of embryo. Orthologous to several human genes including BRS3 (bombesin receptor subtype 3) and GRPR (gastrin releasing peptide receptor).