Synchronization in stress p53 network

We study transition of the temporal behaviours of p53 and MDM2 in a stress p53-MDM2-NO regulatory network induced by a bioactive molecule NO (Nitric Oxide). We further study synchronization among a group of identical stress systems arranged in a 3D array with nearest neighbour diffusive coupling. The role of NO and the effect of noise are investigated. In the single system study, we found three distinct types of temporal behaviour of p53, namely oscillation death, damped oscillation and sustained oscillation, depending on the amount of stress induced by NO, indicating how p53 responds to incoming stress. The correlation among coupled systems increases as the value of the coupling constant (is an element of) is increased (gamma increases) and becomes constant after a certain value of is an element of. The permutation entropy spectra H(is an element of) for p53 and MDM2 as a function of is an element of are found to be different due to direct and indirect interaction of NO with respective proteins. We find gamma versus is an element of for p53 and MDM2 to be similar in a deterministic approach but different in a stochastic approach, and the separation between gamma of the respective proteins as a function of is an element of decreases as system size increases. The role of NO is found to be two-fold: stress induced by NO is prominent at small and large values of is an element of but synchrony induced by it dominates in the moderate range of is an element of. Excess stress induces apoptosis.