Pancreatic polypeptide (PP), neuropeptide Y (NPY), and peptide YY (PYY) are related 36-amino acid hormones. A number of structurally related receptors for these peptides have been isolated, NPY1-R, NPY2-R, NPY3-R, NPY4-R, NPY5-R, and NPY6-R. NPY4-R is expressed in several human tissues, including brain, coronary artery, and ileum. NPY4-R maps to human chromosome 10q11.2. NPY-5R, isolated from rat hypothalamus, encodes a 456-amino acid protein with less than 35% overall identity to known Y-ty