Figure 3.

CaMKII activation curves. CaMKII activity is plotted as a function of Ca²⁺ for various concentrations of PP1, as labeled in the figures. As in Fig. 2B, activity levels at increasing Ca²⁺ increments are shown in blue and those at decreasing Ca²⁺ increments are shown in red. Regions of bistability are easily identified by blue points at the edge of the lower activity curve. The interesting features and notable trends are discussed in the text. The simulations used standard parameters and 200 μM CaMKII.