Figure 2. The GPCR DmX has the best coupling with Gαo protein subtype in HEK transfected cells.

L-canavanine induced-inositol phosphate (IP) production was measured from HEK cells co-expressing the DmX receptor and the indicated Gα protein. As a control, we used HEK cells transfected with DmXR expression vector alone (called ‘No G’). Basal and 10 mM L-canavanine were used for all stimulations, indicated by white and black bars, respectively. IP stimulation was calculated relatively to IP production in basal conditions. HEK cells co-expressing DmXR and Gα₁₅, Gα_qi9 or Gα_qo5 produced IP after L-canavanine stimulation, indicating that these Gα proteins can efficiently couple to DmXR, the best coupling being observed with Gα_qo5. No such effect was observed with HEK cells co-expressing DmXR and Gα₁₆, Gα_q or Gα_qz5. Experiments done with Gα₁₅ could be considered as a positive control because Gα₁₅ protein is known to couple with most GPCRs. Data are means +/− SEM from triplicate experiments. IP production was compared with basal activity using Unpaired Student's t test (* p<0.05, ** p<0.01, *** p<0.001).