FIGURE 5.

C1a is critical for regulatory domain binding. A, as described in the legend to Fig. 4, sensors lacking regions of the regulatory domain of PKCα were digested with TEV protease and the bimolecular interaction fit to determine equilibrium constants. In the schematic, Domain X represents the region of the regulatory domain being tested. B, effect of domain deletion on effector independent ATPase activity of PKCα. Schematics are included for each construct. Activity measurements were taken with 50 μm of both MBP peptide and ATP at 21–22 °C and are reported as mole of ATP per mol of protein per s or s⁻¹. For all experiments, data are derived from at least three independent protein preparations with at least two measurements for each condition per preparation (mean ± S.E., n ≥ 3). ***, p ≤ 0.001; ****, p ≤ 0.0001 (Student's unpaired t test).