Cloning and pharmacological characterisation of the guinea pig 5-ht5A receptor.
The guinea pig 5-hydroxytryptamine(5A) (gp5-ht(5A)) receptor was cloned from guinea pig brain using degenerate polymerase chain reaction (PCR) and shows 88%, 85% and 84% amino acid sequence identity versus the human, rat and mouse 5-ht(5A) receptors, respectively. The receptor was transiently expressed in human embryonic kidney (HEK) 293 cells. [(3)H]-Lysergic acid diethylamide (LSD) bound saturably to gp5-ht(5A)/HEK293 membranes with a K(d) of 2.3+/-0.1 nM and B(max) of 15.7+/-3.4 pmol/mg protein. The receptor binding profile, determined by competition with [(3)H]LSD, correlated well with that for the human 5-ht(5A) receptor. 5-HT stimulated [(35)S]GTPgammaS binding to gp5-ht(5A)/HEK293 membranes (pEC(50) 8.1+/-0.2), and the response was surmountably antagonised by methiothepin and ritanserin, giving apparent pK(B) values of 8.0 and 7.2, respectively. The 5-HT response was absent using membranes prepared from gp5-ht(5A)/HEK293 cells pretreated with pertussis toxin (PTX). These data suggest that the gp5-ht(5A) receptor couples to G(i)-proteins in this expression system and shows a similar pharmacological profile to that for the human 5-ht(5A) receptor.
Thomas
David R
DR
Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park (North), Harlow, Essex, UK. david.r.thomas@gsk.com
Larminie
Christopher G
CG
Lyons
Helen R
HR
Fosberry
Andrew
A
Hill
Matthew J
MJ
Hayes
Philip D
PD
D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry / Q000235:genetics; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D008238:Lysergic Acid Diethylamide / Q000378:metabolism; D008719:Methiothepin / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D011869:Radioligand Assay; D051381:Rats; D011985:Receptors, Serotonin / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012701:Serotonin / Q000031:analogs & derivatives* / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000378:metabolism; D013045:Species Specificity
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C078730:serotonin 5 receptor; D012701:Serotonin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D008719:Methiothepin; D008238:Lysergic Acid Diethylamide; C047087:5-carboxamidotryptamine