Extended Data Fig. 5: Signaling responses to Ca²⁺ and/or baclofen in parathyroid-derived PTH-C1 cells.

a, Time-course of Gq activation. Representative FRET experiments showing stimulatory effect of Ca²⁺ (10 mM) which is suppressible by baclofen (300 µM) in PTH-C1 cells coexpressing the FRET-based Gq sensor (Gq^Turq/YFP) without (-) or with (+) coexpression of recombinant (Recom) CaSR and GABA_B1R. The change in FRET (N_FRET) was calculated according to equation #2 (see On-line Methods) with the initial value at t = 0 set to 1. Similar results were obtained from 2 independent experiments. b, Averaged time courses of cAMP in PTH-C1 cells expressing CaSR without (control in blue) or with pretreatment with cholera toxin (CTx in black). Cells were continuously perfused with buffer without or with extracellular Ca²⁺ or forskolin (horizontal bar). Data were normalized to control with the initial value at t = 0 set to 1 and represent the mean ± SEM of n = 45 cells from 3 separate experiments.