  We study the regulating mechanism of p53 on the properties of cell cycle
dynamics in the light of the proposed model of interacting p53 and cell cycle
networks via p53. Irradiation (IR) introduce to p53 compel p53 dynamics to
suffer different phases, namely oscillating and oscillation death (stabilized)
phases. The IR induced p53 dynamics undergo collapse of oscillation with
collapse time \Delta t which depends on IR strength. The stress p53 via IR
drive cell cycle molecular species MPF and cyclin dynamics to different states,
namely, oscillation death, oscillations of periods, chaotic and sustain
oscillation in their bifurcation diagram. We predict that there could be a
critical \Delta t_c induced by p53 via IR_c, where, if \Delta t < \Delta t_c
the cell cycle may come back to normal state, otherwise it will go to cell
cycle arrest (apoptosis).
