Fig. 5: Gαs–β-arrestin1 (βarr1) interactions modulate βarr1 activation status.
From: Functional and structural insights into interactions between β-Arrestin 1 and Gαs or Gαi1
a Schematic illustration of the fluorescence-based βarr1 β-strand XX (βXX) release assay. In the basal state, βarr1, Gly5, and Asp385, highlighted by yellow and cyan circles, respectively, are in proximity; Gly5 is switched to Trp, and Asp385 is switched to Cys and labeled with Bimane. In the basal state, the Bimane fluorescence is quenched by nearby tryptophan. Upon activation, βXX is released, and the distance between these residues increases, reducing the quenching effect and resulting in enhanced fluorescence. Effects of pre or post co-incubation of GTPγS-bound Gα (b), miniGα (c), and GαAHD (d) on bimane fluorescence changes of βarr1 with or without V2Rpp. Statistical significance was assessed using one-way ANOVA followed by Tukey’s post-hoc test (*P < 0.05) comparing all tested conditions. For simplicity, the statistical significance was noted only for the pairs with functional importance. Data are presented as mean ± SD from 6–7 independent experiments. Exact P-values in (b) are as follows: vehicle vs. V2Rpp, 4.018 × 10⁻¹⁰; V2Rpp vs. V2Rpp+Gαs(post), 0.000773; V2Rpp vs. V2Rpp+Gαs(pre), 0.001929 (n = 6–7). Exact P-values for vehicle vs. V2Rpp in (c) and (d) are 0.000037 and 0.001466, respectively (n = 6).
