Figure 3. Silencing the expression of GRK5 or GRK6 does not modulate Ca²⁺ .

mobilization to low concentrations of C3a. (A) shRNA control, (B) GRK5 KD and (C) GRK6 KD HMC-1 cells were loaded with Indo-1 (1 µM), sequentially exposed to C3a 0.01 nM and 0.1 nM C3a and intracellular Ca²⁺ mobilization was determined. Traces for three representative experiments are shown. For (D), peak Ca²⁺ response to C3a in shRNA control, GRK5 and GRK6 KD cells are shown. Data are the mean ± SEM from three independent experiments.