Computational Model Explains High Activity and Rapid Cycling of Rho GTPases within Protein Complexes
Figure 3
Concentrations of GEF and GAP Define the Efficiency of the GTPase Cycling
The profiles of the GTPase activity (A), recovery time (B), and performance index (C) are plotted as contour lines. While activity remains largely a function of the GEF concentration, the recovery time is determined mostly by the GAP concentration. Performance maximum with the activity 85% and recovery time ∼3 min is attained at E0 = 0.78 mM and A0 = 0.66 μM. Further increase in the turnover rate can be achieved at the expense of activity. Numbers on the contour lines indicate the levels of the respective characteristics. Total GTPase concentration is R0 = 1 mM.