Computational Model Explains High Activity and Rapid Cycling of Rho GTPases within Protein Complexes
Figure 2
GTPase Cycling in the GEF-Only System
The values of the GTPase activity (A), recovery time (B), and performance index (C) are shown as functions of the total concentrations of the GTPase (R0) and GEF (E0). The model predicts that in the physiologically relevant range of the GTPase concentrations (R0 ≤ 10 mM) all three characteristics do not depend on R0. Roman numerals on the contour plot of the performance index P denote three regions with distinct GTPase cycling regimes: (I) effectively control-free, (II) processive (P > 0.1, highlighted in light grey), and (III) futile cycling within the complex with the GEF. Numbers on the contour lines indicate the levels of P.