Dynamical behaviors from the signaling transduction network shown in Fig. 1. (A–D) Active cyclin-CDK (x) versus time at different dynamical regimes. (A) Stable low kinase activity. (B) Stable high kinase activity. (C) Bistability. Starting from different initial conditions, the system approached to different steady state. (D) Bifurcation diagram of bistability. Dashed segment is the unstable steady state. Shaded arrows indicate the hysteresis loop. (E) Limit cycle oscillation. (F) Bifurcation diagram of limit cycle. Solid circles are stable steady states and open circles are the maxima and minima of the limit cycle oscillation. (G) Complex (period-2) dynamical behavior. (H) Complex (chaotic) dynamical behavior. (I) Active cyclin-CDK versus free CDK for the period-2 dynamics in G. (J) Active cyclin-CDK versus free CDK for the chaotic oscillations in H. The parameters for A–D are: = 0.5, = 8.64, = 0.094, = 0.72, = 0.75, = 0.57, = 15.8, = 1/3, = 3.92, = 1/3, = 26.31, = 1/3, = 0.215, = 0.8, = 0.085, = 0.8, = 0.06, = 0.37, = 6.3, = 7.6, = 5.6, = 5.2, = 2.5, = 7.4, α0 = 0.015, α1 = 0.015, α2 = 1, β0 = 1, β1 = 0.72, β2 = 0.19, γ0 = 0.02, γ1 = 0.91, and γ2 = 1. The parameters for E and F are: = 0.5, = 0.4, = 0.33, = 0.83, = .013, = 1, = 24.8, = 1/3, = 5.6, = 1/3, = 24.5, = 1/3, = 0.12, = 0.65, = 0.82, = 0.74, = 0.74, = 0.17, = 7.9, = 0.31, = 9.5, = 3.5, = 5.2, = 9.0, α0 = 0.011, α1 = 0.61, α2 = 1, β0 = 1, β1 = 0.70, β2 = 0.19, γ0 = 0.0058, γ1 = 0.26, and γ2 = 1. The cyclin synthesis rate in each panel is: (A) = 8.0; (B) = 30; (C) = 13.9; and (E) = 1.92. The parameters for G and I are: = 12.4, = 0.83, = 0.27, = 6.65, = 0.99, = 0.9, = 0.14, = 28.9, = 1/3, = 93, = 71.8, = 7.74, = 1/3, = 77.4, = 14, = 32.7, = 1/3, = 70.9, = 17.7, = 5.0, = 2.0, = 0.23, = 0.18, = 0.625, = 0.78, = 0.9, = 0.19, = 9.5, = 4.8, = 7.1, = 10, = 1.15, = 4.23, α0 = 0.07, α1 = 0.155, α2 = 1, β0 = 1, β1 = 0.81, β2 = 0.1, γ0 = 0.02, γ1 = 0.76, γ2 = 1, and τ = 20. The parameters for H and J are: = 32.98, = 0.1, = 0.365, = 9.94, = 0.33, = 0.965, = 0.164, =19.1, = 1/3, = 99.9, = 97.5, = 8.68, = 1/3, = 86.8, = 88.9, = 29.96, = 1/3, = 79.3, = 39.45, = 5.0, = 1.0, = 0.07, = 0.07, = 0.71, = 0.054, = 0.066, = 0.0065, = 6.29, = 6.58, = 6.14, = 2.4, = 0.94, = 1.27, α0 = 0.134, α1 = 0.118, α1 = 1, β0 = 1, β1 = 0.298, β2 = 0.07, γ0 = 0.013, γ1 = 0.34, γ2 = 1.0, and τ = 20.