Fecha de publicación: 13/11/2003 Fuente: WIPO "apis mellifera" The invention relates generally to compositions of and methods for obtaining opioid receptor polypeptides. The invention relates as well to polynucleotides encoding opioid receptor polypeptides, the recombinant vectors carrying those sequences, the recombinant host cells including either the sequences or vectors, and recombinant opioid receptor polypeptides. By way of example, the invention discloses the cloning and functional expression of at least three different opioid receptor polypeptides. The invention includes as well, methods for using the isolated, recombinant receptor polypeptides in assays designed to select and improve substances capable of interacting with opioid receptor polypeptides for use in diagnostic, drug design and therapeutic applications.