Transient analysis of Diffusion for charged molecules to model the input process in a stochastic event based simulation framework for the PhoPQ signal transduction system

With biological experiments generating lots of empirical data, the challenge is to develop a modeling paradigm that integrates structural, molecular and genetic data for a quantitative understanding of physiology and behavior of biological processes at multiple scales starting from cell, to tissues and finally to the whole organism. The complexity of the problem motivates the use of computer or ”in silico” stochastic event based modeling approach. We present the discrete event framework of the signal transduction cascade triggered by extra-cellular Mg concentration in the two component PhoPQ regulatory system of Salmonella Enterica serovar Thphimurium. We also present the mathematical formulation for the estimation of statistical parameters of interarrival time of molecules/ions to a cell receptor as external signal. In particular, we present the transient analysis of a diffusion model for charged ions to model the input process in our discrete event simulation structure.