Figure 2: C781 reduces PAR2-dependent β-arrestin/MAPK signalling without effects on Gq/Ca²⁺ signalling.

β-arrestin binding in 16HBE14o- cells was monitored in response to a concentration response of 2AT in the absence (A) or presence (B) of 3 μM C781. 2AT induced an increased binding of β-arrestin that was significantly reduced across 2AT concentrations. (C) C781 significantly reduced phosphorylation of ERK1/2 (pMAPK) in response to a full agonist dose of 2AT (600 nM) beginning at 1 μM (D). C781 (3 μM) had no effect on 2AT-induced Ca²⁺ signalling across a concentration range €. Data are plotted with SEM and represent n = 7, 8 for β-arrestin and pMAPK studies; 6 ≤ n ≤ 10 for Ca²⁺ studies. * represents significant difference from control.