IMA Postdoc Seminar (December 16, 2008)

Speaker: Srividya Jeyaraman (IMA)

Title: Time Lags in Signaling Cascades

Abstract: Biochemical Signaling cascades are the primary source of information transfer in cellular mechanisms. Cell signaling is predominantly achieved by Phosphorylation-Dephosphorylation (PD) reactions knit in a cascade like fashion. These cascades respond to a stimulus and conduct the information that regulates several key events within the cell. Mathematical models of these cascades predict a phenomenon called "Zero-order Ultrasensitivity" which corresponds to an unusually increased sensitivity to conduct the signals across the cascades. This has been confirmed experimentally. However, experiments have also observed a certain time lag in the response of these cascades. In this talk I will discuss the effect of time lag in some of the mathematical models to see what effect they may bring in. A small amount of time lag brings in the capability of sustained signal transduction even when the stimulus strength is very weak. This suggests that PD cascades coupled with time lags may be one of the fundamental mechanisms of signal transduction in cellular processes under weak stimuluses.