Fig. 2.

Reporter assay and light-activated reference GPCRs. a Reporter vectors express firefly luciferase (FF) under the control of signaling-specific enhancers and were co-transfected with Renilla luciferase (RE) to normalize for cell numbers/transfection efficiencies. Relative light units (RLU) were detected for both luciferases separately. b Reporter activation by reference GPCRs stimulated by agonists (Supplementary Table 2; here, only receptors that stimulated reporters are shown). c Reporter activation by the light-activated variants of reference GPCRs. In b and c, mean values ±s.e.m. (n = 6–8, 3–4 independent experiments) are shown. In tests for cAMP reduction, cAMP production was stimulated chemically before light treatment, as described in Methods