| Autor: |
J M, Zgombick, R L, Weinshank, M, Macchi, L E, Schechter, T A, Branchek, P R, Hartig |
| Rok vydání: |
1991 |
| Předmět: |
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| Zdroj: |
Molecular pharmacology. 40(6) |
| ISSN: |
0026-895X |
| Popis: |
RDC4 is a guanine nucleotide-binding protein-coupled receptor clone originally isolated from a canine thyroid cDNA library by Libert and colleagues [Science (Washington D. C.) 244:569-572 (1989)]. We have isolated the corresponding genomic clone for RDC4, have expressed this clone in murine LM (tk-) fibroblasts, and have determined that it encodes a serotonin 5-hydroxytryptamine1D (5-HT1D) receptor. RDC4 is an intronless gene encoding a protein of 377 amino acids, which exhibits greatest sequence identity (43%) to the 5-HT1A receptor and lower overall homology to other serotonergic and catecholaminergic receptors. Membranes prepared from murine LM (tk-) fibroblasts stably transfected with this clone were shown to bind [3H]5-HT in a saturable manner and displayed an apparently homogeneous population of high affinity (Kd = 3.6 nM, Bmax = 275 fmol/mg of protein) [3H]5-HT binding sites. High affinity [3H] 5-HT binding was unchanged using assay conditions [1 microM (+/- )-pindolol and 1 microM (R)-(+/- )-SCH 23390) to pharmacologically mask 5-HT1A, 5-HT1B, and 5-HT1C receptors. Serotonergic ligands displaced specific [3H]5-HT binding with a rank order of potency expected of a 5-HT1D receptor subtype, 5-carboxyamidotryptamine greater than 5-HT greater than yohimbine greater than 8-hydroxy-2-(di-n-propylamino)tetralin greater than ketanserin = spiperone greater than zacopride. Further, transfected cells responded to addition of 5-HT by decreasing the level of forskolin-stimulated cAMP accumulation. These data indicate that the gene RDC4 encodes a functional 5-HT1D receptor. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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