Figure 2. Schematic representation of our model.

(A) Blue circles represent membrane proteins and green circles represent modulators of endocytosis. Membrane proteins and modulators of endocytosis can diffuse along the cell membrane. Arrows indicate biological events: magenta, spontaneous membrane association; red, positive feedback; black, endocytosis; ocher, spontaneous activation; cyan, deactivation; green, activation through recruitment; blue, lateral diffusion for membrane proteins and modulators of endocytosis. The solid line represents the cell membrane (total length, ). (B) activator-inhibitor scheme. In our model, membrane proteins and modulators of endocytosis play the roles of activator and inhibitor, respectively. For polarity domain formation modulators of endocytosis have to diffuse faster than membrane proteins.