Figure 3.

Bistable and monostable characteristics of the αCaMKII–CPEB1-positive feedback loop. Solid line represents αCaMKII concentration, without the application of (Ca²⁺)₄–CaM pulse and the dashed line represents αCaMKII concentration on application of a brief (Ca²⁺)₄–CaM pulse. All simulations are carried out with identical parameters, except the αCaMKII turnover rate (A) τ=111.0 h (B) τ=2.78 h (C) τ=0.4 h (D) τ=0.27 h. For a slow turnover rate, the switch is monostable (A), as the turnover rate is increased, the switch becomes bistable (B and C), and at a faster turnover rate, the switch becomes monostable again (D).