Functional coupling of a recombinant human 5-HT5A receptor to G-proteins in HEK-293 cells.
1. We have cloned, expressed and pharmacologically characterized the Human 5-HT5A receptor. 2. We have shown that ligand activation of the Human 5-HT5A receptor results in functional coupling to G-proteins in HEK-293 cells. 3. Stimulation of the receptor with 5-CT (5-carboxamidotryptamine) resulted in a dose-dependent increase in the % [35S]-GTPgammaS binding over the basal level. This is the first study to describe such G-protein activation for the Human 5-HT5A receptor in any cell. 4. A dose-dependent inhibition of cyclic AMP accumulation was observed in the recombinant Human 5-HT5A receptor cell line, suggesting a functional coupling to a G alpha i, G-protein in the HEK-293 cell line. 5. A ligand-stimulated reduction in the detectable level of the catalytic domain of protein kinase A (PKA) in nuclear extracts isolated from Human 5-HT5A expressing cells was observed. This observation was consistent with the reduction in the level of cyclic AMP accumulation, in response to receptor activation.
Hurley
P T
PT
National Agriculture and Veterinary Biotechnology Centre and Department of Pharmacology, University College Dublin, Belfield, Ireland.
McMahon
R A
RA
Fanning
P
P
O'Boyle
K M
KM
Rogers
M
M
Martin
F
F
D000595:Amino Acid Sequence; D001483:Base Sequence; D020134:Catalytic Domain; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D003001:Cloning, Molecular; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D017931:DNA Primers; D018076:DNA, Complementary; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011985:Receptors, Serotonin / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D017931:DNA Primers; D018076:DNA, Complementary; D011985:Receptors, Serotonin; D011994:Recombinant Proteins; D017366:Serotonin Receptor Agonists; C078730:serotonin 5 receptor; D005576:Colforsin; D012701:Serotonin; C047087:5-carboxamidotryptamine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D019204:GTP-Binding Proteins