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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
|
| pubmed:dateCreated |
1990-3-7
|
| pubmed:abstractText |
We have previously described a cDNA which encodes a binding site with the pharmacology of the D2-dopamine receptor (Bunzow, J. R., VanTol, H. H. M., Grandy, D. K., Albert, P., Salon, J., Christie, M., Machida, C., Neve, K. A., and Civelli, O. (1988) Nature 336, 783-787). We demonstrate here that this protein is a functional receptor, i.e. it couples to G-proteins to inhibit cAMP generation and hormone secretion. The cDNA was expressed in GH4C1 cells, a rat somatomammotrophic cell strain which lacks dopamine receptors. Stable transfectants were isolated and one clone, GH4ZR7, which had the highest levels of D2-dopamine receptor mRNA on Northern blot, was studied in detail. Binding of D2-dopamine antagonist [3H]spiperone to membranes isolated from GH4ZR7 cells was saturable, with KD = 96 pM, and Bmax = 2300 fmol/mg protein. Addition of GTP/NaCl increased the IC50 value for dopamine competition for [3H]spiperone binding by 2-fold, indicating that the D2-dopamine receptor interacts with one or more G-proteins. To assess the function of the dopamine-binding site, acute biological actions of dopamine were characterized in GH4ZR7 cells. Dopamine, at concentrations found in vivo, decreased resting intra- and extracellular cAMP levels (EC50 = 8 +/- 2 nM) by 50-70% and blocked completely vasoactive intestinal peptide (VIP) induced enhancement of cAMP levels (EC50 = 6 +/- 1 nM). Antagonism of dopamine-induced inhibition of VIP-enhanced cAMP levels by spiperone, (+)-butaclamol, (-)-sulpiride, and SCH23390 occurred at concentrations expected from KI values for these antagonists at the D2-receptor and was stereoselective. Dopamine (as well as several D2-selective agonists) inhibited forskolin-stimulated adenylate cyclase activity by 45 +/- 6%, with EC50 of 500-800 nM in GH4ZR7 membranes. Dopaminergic inhibition of cellular cAMP levels and of adenylyl cyclase activity in membrane preparations was abolished by pretreatment with pertussis toxin (50 ng/ml, 16 h). Dopamine (200 nM) abolished VIP- and thyrotropin-releasing hormone-induced acute prolactin release. These data show conclusively that the cDNA clone encodes a functional dopamine-D2 receptor which couples to G-proteins to inhibit adenylyl cyclase and both cAMP-dependent and cAMP-independent hormone secretion.
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| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/1-Methyl-3-isobutylxanthine,
http://linkedlifedata.com/resource/pubmed/chemical/Adenylate Cyclase,
http://linkedlifedata.com/resource/pubmed/chemical/Adenylate Cyclase Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Pertussis Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Prolactin,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Dopamine,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Dopamine D2,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors, Bordetella
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Feb
|
| pubmed:issn |
0021-9258
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
5
|
| pubmed:volume |
265
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
2098-104
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:1688845-1-Methyl-3-isobutylxanthine,
pubmed-meshheading:1688845-Adenylate Cyclase,
pubmed-meshheading:1688845-Adenylate Cyclase Toxin,
pubmed-meshheading:1688845-Animals,
pubmed-meshheading:1688845-Blotting, Northern,
pubmed-meshheading:1688845-Cell Line,
pubmed-meshheading:1688845-Cell Membrane,
pubmed-meshheading:1688845-Cloning, Molecular,
pubmed-meshheading:1688845-Cyclic AMP,
pubmed-meshheading:1688845-Dopamine,
pubmed-meshheading:1688845-GTP-Binding Proteins,
pubmed-meshheading:1688845-Kinetics,
pubmed-meshheading:1688845-Pertussis Toxin,
pubmed-meshheading:1688845-Plasmids,
pubmed-meshheading:1688845-Prolactin,
pubmed-meshheading:1688845-RNA, Messenger,
pubmed-meshheading:1688845-Receptors, Dopamine,
pubmed-meshheading:1688845-Receptors, Dopamine D2,
pubmed-meshheading:1688845-Recombinant Proteins,
pubmed-meshheading:1688845-Transcription, Genetic,
pubmed-meshheading:1688845-Transfection,
pubmed-meshheading:1688845-Virulence Factors, Bordetella
|
| pubmed:year |
1990
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| pubmed:articleTitle |
Coupling of a cloned rat dopamine-D2 receptor to inhibition of adenylyl cyclase and prolactin secretion.
|
| pubmed:affiliation |
Vollum Institute for Advanced Biomedical Research, Oregon Health Science University, Portland.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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