Figure 7.

Plot of Cdc42-GTP and GEF concentration gradient when the rate of GAP_II recruitment to the cell tips is $k_5^n=0.03 /s$ (empty symbols) and for the same parameters with reduced rate of $k_5^n=0.015 /s$ (solid symbols), as might occur in rga4Δ cells. Other parameters are the same as Table 1 except $k_{\mathrm{sat}}=450 /{\mathsf{\mu }\mathrm{m}}^2$, such cases result in BPO oscillations (see Figure 5B). This plot shows the concentration profiles at the dominant tip ~ 20 s after Cdc42-GTP tip concentration peaks, and after at least 1000 s of simulation time. The half-widths are larger with reduced GAP_II recruitment rate: An exponential fit to the Cdc42-GTP profile gives a decay length $0.64\pm 0.01 \mathsf{\mu }\mathrm{m}$ and $0.72\pm 0.01 \mathsf{\mu }\mathrm{m}$, respectively. The left-most point on the x axis corresponds to the left tip, as in Figure 2.