Analyses On Dynamics Of P53 Signaling Pathway Regulated By PDCD5

The biological system can be explored at molecular level due to a discovery of DNA double helix structure.The signal transduction of biological system at the molecular level is realized by an interaction of DNA,RNA,and protein in cells,and then the signal transduction pathway is constructed.The interaction of various components in the signal transduction pathway is caused by a series of biochemical reactions,which can be described by mathematical models.By studying the mathematical model with theory and method of mathematics,we can understand a changes in the expression level of each component in the pathway and explore the mechanism of life.The signal pathway related to cancer is the network of proteins with a core p53 protein and the proteins that interact with p53.External pressure can activate p53 expression in the cell,while the activated p53 promotes different downstream gene expression so as to trigger different cell fates.These cell fates are related to p53 dynamics.Bifurcation theory in dynamical system can be used to explore the regulation of various factors in the p53 signaling pathway on p53 dynamics,and these play a guiding role in determining cell fate.In this paper,based on p53 signaling pathway regulated by PDCD5,we consider the expression ofPDCD5 and ATM,two essential proteins in the pathway.Firstly,the typical Codimension one bifurcation diagram of p53 with respect to ATM generation rate is given at a certain PDCD5 expression level.Further,the Codimension two bifurcation diagram of PDCD5 and ATM generation rate clearly shows their regulation on p53 dynamics,then the corresponding time history and phase diagram are given.Finally,the stablity of p53 dynamics is further analyzed by potential landscapes.