The C-truncated delta-opioid receptor underwent agonist-dependent activation and desensitization.
The agonist-dependent activation and desensitization of a recombinant analog of delta-opioid receptor lacking the carboxyl-terminal (C-terminal) 31 residue peptide segment were discussed. The cDNA of the C-truncated delta-opioid receptor was created by polymerase chain reaction (PCR), stably expressed in Chinese hamster ovary cells and characterized by binding assay and function assay. Agonist [D-Pen2, D-Pen5]-enkephalin (DPDPE) stimulated the specific [35S]GTPgammaS binding to membrane fragments of cells expressing the C-truncated and the wild-type delta-opioid receptors in different levels dose-dependently. EC50 values of DPDPE on truncated and wild-types in stimulation were very similar. Agonist-dependent desensitization, which could be blocked by protein kinase inhibitor staurosporine (Stau), was observed after pretreating truncated receptors with 1 microM DPDPE for 10 min, the same as wild-types. The results reveal that the C-terminal of the delta-opioid receptor is not involved in controlling the G-protein activation and phosphorylation-related functional desensitization.
Wang
C
C
Shanghai Institute of Materia Medica, Shanghai Institute of Cell Biology, Chinese Academy of Sciences, 294 Tai-yuan Road, Shanghai, 200031, People's Republic of China.
Zhou
D
D
Cheng
Z
Z
Wei
Q
Q
Chen
J
J
Li
G
G
Pei
G
G
Chi
Z
Z
D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D051379:Mice; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D047428:Protein Kinase Inhibitors; D017465:Receptors, Opioid, delta / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019311:Staurosporine / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014162:Transfection
D004745:Enkephalins; D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D047428:Protein Kinase Inhibitors; D017465:Receptors, Opioid, delta; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D020881:Enkephalin, D-Penicillamine (2,5)-; D019311:Staurosporine