We report isolation of a murine gene, NPYR-D, which predicts an intronless novel G protein-coupled receptor of 375 amino acids. Percent identities of NPYR-D to the clone Y1, Y2, rat Y4/PP1 and human Y4/PP1 receptors are 45, 32, 92 and 76, respectively. Southern blots indicate that NPYR-D and human Y4/PP1 receptor genes are species homologues. Rat [125I]pancreatic polypeptide ([125I]rPP) bound to NPYR-D transfected COS-7 cell membranes with a high affinity, i.e. IC50=90 pM. Pharmacological characterization of [125I]rPP binding showed a rank order of potency of P >> PYY > or = NPY, such that PYY and NPY were at least 5000-fold weaker than PP. Interestingly, [125I]rPYY binding produced the same rank order, but PYY and NPY were only 25-fold weaker than PP, which had an IC50 value of approximately 120 pM. Tissue distribution studies in mouse and humans suggest potential roles of this novel receptor in the gastrointestinal tract, heart, prostate, as well as in neural and endocrine signalling.