QUALITATIVE AND QUANTITATIVE MODELING OF INSULIN SIGNALING PATHWAY

Abstract

Signal transduction occurs when cell responds to some external stimulus. In this way information regarding external stimulus is conveyed to different portions of cell for suitable action. This signal transduction constitutes a series of chemical interactions/modifications and can be represented in many forms. Graphical representation of this process is called signaling pathway. The large number of chemical interactions and presence of cross talk make the pathway too complicated to be fully analyzed. Any defect/mutation of protein can change the correct behaviour of pathway. It is essential to carry out both qualitative and quantitative analysis to fully understand the complexities of these signaling pathways. Pathway Logic (PL) is a computational framework for the qualitative analysis of signaling pathways. Moreover, its ability to represent the pathways in Petri net form leads to the quantitative analysis using quantitative Petri net (QPN) tools. In this thesis we have taken chemical interactions involved in Insulin signaling and modeled it in Pathway Logic to identify the cross talk within insulin pathway. This complete pathway is analyzed for structural properties using Petri net theory. Moreover, a quantitative analysis of a part of the complete pathway is performed using quantitative Petri net to get insight into dynamic aspects of this pathway. The time histories of activation and deactivation of proteins are found. Moreover, the steady state concentrations are also found.