Figure 6.

Rapid fluctuations in rate parameters lead to variations in the amplitude of the p53/Mdm2 oscillations, but preserve their period. For the sake of simplicity, all k_s, r,d^p53lowast; and k_s,r,d^Mdm2lowast; rate constants are set to zero. (a and b) Variations for k_s^p53 and $k_{\text{cat}}^{E_{\text{d}}}$, respectively; see also Supporting Material. (c) Resulting oscillations in p53 and Mdm2 levels when applying rapid fluctuations for all rate parameters within the ranges indicated by Table S1 in the Supporting Material. Rate constant values of k and k_s^Mdm2 have been adjusted such that the period of the harmonic unperturbed oscillations is close to the experimental value of 5.5 h (27). (d) Observed p53 (solid line) and Mdm2 (dashed line) oscillations in single cells. (Replotted from upper left of Fig. 1B in Geva-Zatorsky et al. (27).)