Functional characterisation of the Drosophila 5-HTdro1 and 5-HTdro2B serotonin receptors in insect cells: activation of a Gαs-like protein by 5-HTdro1 but lack of coupling to inhibitory G-proteins by 5-HTdro2B

Abstract Insect cells are routinely used for the production of receptor proteins. Expression of the Drosophila 5-HT dro 1 serotonin receptor resulted in positive coupling of the receptor to adenylyl cyclase via the G α s G-protein subtype. The Drosophila 5-HT dro2B receptor stimulated the metabolism of inositol phospholipid via a pertussis toxin-insensitive G-protein, but exhibited no detectable inhibition of adenylyl cyclase. Immunoblot analysis of the endogenous G-proteins revealed that Sf9 cells lack the G-protein subtypes G α i 1–3 and G α0 , but express the subtypes G α s and G α q .