Endogenous opioid receptor-like receptor in human neuroblastoma SK-N-SH cells: activation of inhibitory G protein and homologous desensitization.
Endogenous expression of opioid receptor-like receptor (ORL1), in human neuroblastoma SK-N-SH cells was demonstrated by binding with nociceptin/ orphanin FQ (N/OFQ). Scatchard analysis of [3H]N/ OFQ saturation binding data gave Kd = 1.3 +/- 0.1 nM and Bmax = 1.58 +/- 2.5 fmol/mg protein. N/OFQ stimulation increased [35S]GTP gamma S binding to cell membranes and attenuated forskolin-induced cAMP accumulation in a concentration-dependent manner. The effects of N/OFQ were eliminated by the pretreatment of pertussis toxin (PTX) but not by the antagonists of opioid receptors, revealing mediation of N/OFQ signal transduction by ORL1 receptor and PTX sensitive G protein(s). The ability of N/OFQ to inhibit cAMP production was greatly reduced after prechallenging with N/OFQ, indicating that ORL1 undergoes homologous desensitization in neuronal cells.
Cheng
Z J
ZJ
Shanghai Institute of Cell Biology, Chinese Academy of Sciences, People's Republic of China.
Fan
G H
GH
Zhao
J
J
Zhang
Z
Z
Wu
Y L
YL
Jiang
L Z
LZ
Zhu
Y
Y
Pei
G
G
Ma
L
L
D001932:Brain Neoplasms / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D009447:Neuroblastoma / Q000378:metabolism*; D018847:Opioid Peptides / Q000494:pharmacology; D011957:Receptors, Opioid / Q000819:agonists / Q000096:biosynthesis / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013462:Sulfur Radioisotopes; D014407:Tumor Cells, Cultured; D000094942:Nociceptin Receptor; D000097629:Nociceptin
D019204:GTP-Binding Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D018847:Opioid Peptides; D011957:Receptors, Opioid; D013462:Sulfur Radioisotopes; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C000722283:OPRL1 protein, human