FIGURE 4.

(Left column) Spatial profiles of PIs (from top to bottom: PIP₁, PIP₂, PIP₃); (middle column) Active Rho proteins (Cdc42, Rac, Rho); and (right column) actin (barbed ends, Arp2/3, and filament density) in response to the stimulus described in Fig. 3 a. The spatial profiles are consistent with experimental observations, with PIP₂, PIP₃, Cdc42, and Rac elevated at the front of the cell and Rho elevated at the rear. The dotted line shows the homogeneous prestimulus distribution (i.e., before a gradient is applied to k_PI3K and k_PTEN), while the solid line shows the post-stimulus steady-state distribution. The leading edge of the cell is on the right in each frame.