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Pharmacological analysis of a dopamine D 2Short :G αo fusion protein expressed in Sf9 cells
Author(s) -
Gazi Lucien,
Wurch Thierry,
Lopéz-Giménez Juan F.,
Pauwels Petrus J.,
Strange Philip G.
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00520-9
Subject(s) - sf9 , dopamine , chemistry , fusion , g protein , fusion protein , biochemistry , neuroscience , biology , recombinant dna , gene , receptor , linguistics , philosophy , spodoptera
A dopamine D 2Short receptor:G αo fusion protein was expressed in Sf9 cells using the baculovirus expression system. [ 3 H]Spiperone bound to D 2Short :G αo with a p K d ≈10. Dopamine stimulated the binding of [ 35 S]guanosine‐5′‐ O ‐(3‐thio)triphosphate (GTPγS) to D 2Short :G αo expressed with Gβ 1 γ 2 ( E max >460%; pEC 50 5.43±0.06). Most of the putative D 2 antagonists behaved as inverse agonists (suppressing basal [ 35 S]GTPγS binding) at D 2Short :G αo /Gβ 1 γ 2 although (−)‐sulpiride and ziprasidone were neutral antagonists. Competition of [ 3 H]spiperone binding by dopamine and 10,11‐dihydroxy‐ N ‐ n ‐propylnorapomorphine revealed two binding sites of different affinities, even in the presence of GTP (100 μM). The D 2Short :G αo fusion protein is therefore a good model for characterising D 2 receptors.