Figure 2. How increasing the number of kinases within the module and processive vs. distributive activating phosphorylation mechanisms change signal output. Different modules that contained increasing number of kinases (1T = one-tiered kinase module, 2T = 2-tiered kinase module etc), with each kinase activated through either processive [P], or distributive [D] phosphorylation, were constructed and their signal outputs tested in silico. The Hill co-efficient [H] for each system was calculated and is displayed in the box within each panel. (A) One-tiered processive (solid black lines) and one-tiered distributive (blue dashed line). (B) Tow tiered processive-procecessive (P-P solid black line), processive-distributive (P-D dashed blue line) and 2 tiered distributive-distributive (DD solid green line). (C) Three tiered processive-processive-distributive (P-P-D solid black line) and processive-distributive-distributive (P-D-D solid green line). (D) Four tiered processive-processive-processive-distributive. (E) Four tiered processive-processive-distributive-distributive. (F) Four tiered processive-distributive-distributive-distributive.