The Near-Death Experience of Delta Opioid Receptors Leads to New Drug Targets

The fate of newly synthesized hδORs. On the left, receptors (represented by seven-transmembrane–spanning figures with yellow transmembrane domains) under endogenous conditions whereby only forty percent of the receptors reach the plasma membrane; the remaining sixty percent are retained in the ER, and are exported to the cytosol for proteasomal degradation. On the right, hδORs in the presence of a lipophilic hδOR ligand (represented by green-filled ovals) are processed through the ER more efficiently, so that fewer receptors are degraded and there is a concomitant increase in surface expression of receptor.