Fig. 3.

Effect of controlled proteolysis on the activity of WT and mutant ACA8. The microsomal fraction purified from yeast expressing WT or mutant ACA8 was treated with (white and grey bars) or without (black bars) trypsin as detailed in the Materials and methods; ACA8 activity was measured in the presence (black and grey bars) or absence (white bars) of 1 μM CaM. Results are shown as percentage stimulation over the activity measured in control membranes in the absence of added CaM. Values reported are the mean of 3–5 experiments ±SEM.