Specific reduction of delta-opioid receptor binding in transfected NG108-15 cells.
We have recently identified and sequenced the cDNA for an opioid-binding protein with homologies to cell adhesion molecules (OBCAM) (Schofield, P. R., McFarlard, K. C., Hayflick, J. S., Wilcox, J. N., Cho, T. M., Roy, S., Lee, N. M., Loh, H. H., and Seeburg, P. H. (1989) EMBO J. 8, 489-495). Several lines of evidence using antibodies suggest that OBCAM may play a functional role in NG108-15 neuroblastoma x glioma cells, a useful model system that contains a homogeneous population of delta-opioid receptors. A logical extension of this research is to further test this hypothesis. As part of this study, NG108-15 cells were stably transfected with either sense or antisense sequences of a portion of pROM, the rat cDNA for OBCAM. [3H] Diprenorphine binding was greatly reduced in antisense-transfected cells relative to non-transfected cells. Binding to alpha 2-adrenergic, muscarinic, and insulin receptors was unaffected. These results further support the notion that OBCAM or its analogue is part (or a subunit) of an opioid receptor. Furthermore, our observation of an apparently specific reduction in opioid binding in these transfected cells suggests that they may provide a novel genetic approach for studying regulation of the opioid receptor in this defined cell line.
Ann
D K
DK
Department of Pharmcology, University of Minnesota Medical School, Minneapolis 55455.
Hasegawa
J
J
Ko
J L
JL
Chen
S T
ST
Lee
N M
NM
Loh
H H
HH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D015152:Blotting, Northern; D002417:Cattle; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004174:Diprenorphine / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000235:genetics; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011957:Receptors, Opioid / Q000235:genetics / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D012601:Scopolamine / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection; D014407:Tumor Cells, Cultured; D015016:Yohimbine / Q000378:metabolism
D015815:Cell Adhesion Molecules; D007328:Insulin; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D004174:Diprenorphine; D015016:Yohimbine; D004247:DNA; D012601:Scopolamine