Extended Data Fig. 4: ACh potencies are similar across all seven M2R biosensors.
From: Ligand-specific activation trajectories dictate GPCR signalling in cells
(a-g) Representative traces of concentration-dependent changes of fluorescence intensity (ΔF/F0) of a single cell expressing the indicated M2R biosensor (SP-M2RXXXTAG), stimulated with increasing concentrations of ACh, indicated as log (M) and by a grey colour gradient. (h) Concentration-effect-curves of normalized, mean ACh-mediated fluorescence intensity changes in response to increasing concentrations of ACh. ACh potencies (logEC50 ± sem): T84, −5.9 ± 0.05; E175, −6.4 ± 0.01; F181, −5.7 ± 0.03; F188, −5.5 ± 0.03; A414, −5.8 ± 0.02; P415, −6.2 ± 0.02; N419, −5.4 ± 0.05. n = 10 (T84), n = 19 (E175), n = 21 (F181), n = 20, n = 20 (188), n = 29 (A414), n = 15 (P415), n = 13 (N419). Data obtained from 3 independent experiments. (i) Plot of maximal ΔFRET responses of the Gαi3-FRET assay (see Extended Data Fig. 2) and ACh potencies at the seven biosensors. The data were fitted by linear regression. R2, goodness of fit.
