FIGURE 6.

Regulation of AtMKP1 phosphatase activity by CaM using OMFP. Phosphatase activity was measured at varying concentrations of CaM, with a fixed amount (80 μg) of each recombinant protein and OMFP (500 μm) in the presence of 1 mm CaCl₂ or 5 mm EGTA. A, wild type (WT); B, CaMBDI mutant (W453R); C, CaMBDII mutant, (W678R); D, CaMBDI and CaMBSII mutants (W453R+W678R). Activity was presented as picomoles/min of the OMF released during the reaction. Data are presented as mean values from at least four independent assays.