Figure 7.

The D¹⁰⁰E GCAP1 mutant stimulates both ONE-GC and ROS-GC1 at high Ca²⁺ concentration but only ROS-GC1 in the absence of Ca²⁺. The membrane fraction of COS cells expressing ONE-GC or ROS-GC1 (control) were assayed for guanylate cyclase activity in the presence (2 μM) or absence of D¹⁰⁰E GCAP1 mutant and 1 mM EGTA (10 μM Ca²⁺) or 10 μM Ca²⁺. The experiment was done in triplicate and repeated two times for reproducibility. The results shown are average ± SD from these experiments.