Fig. 1.

Kinetic insulation. (A) Pathways A and B share the component C. The terminal kinases, KA and KB, must respond to external cues received by receptors, RA and RB, respectively. (B) Slow kinetics prevents KA from being activated by a short transient signal, whereas the adaptive nature of KB prevents its activation by a slowly varying signal. (C and D) The temporal profiles of KA (black solid lines) and KB (black dashed lines) activity when component C is exposed to a slowly increasing signals (C, gray line) and square pulse lasting 45 min (D, gray line).