CLONING, EXPRESSION AND CLASSIFICATION OF A KAPPA(3)-RELATED OPIOID RECEPTOR USING ANTISENSE OLIGODEOXYNUCLEOTIDES

Using degenerate oligodeoxynucleotide primers based upon the predicted amino acid sequence of the cloned delta receptor in RT-PCR we isolate d a cDNA of approximately 500 bases with high homology to the cloned d elta, mu and kappa, receptors. Before proceeding to clone the full len gth coding region, we designed an antisense oligodeoxynucleotide (ODN) and examined ifs actions in vivo. Administered intracerebroventricula rly, the antisense ODN effectively blocks the analgesic actions of the kappa, agent naloxone benzoylhydrazone (NalBzoH) without affecting mo rphine (mu) analgesia. A mismatch ODN identical in base composition to the antisense but with four bases out of sequence is inactive. Having established the relevance of the sequence, we proceeded to clone the full length cDNA from a mouse brain library and characterize the expre ssed protein.