Alladi Ramakrishnan Hall

Trade-off between response sensitivity and information flow in an intracellular signaling pathway

Soumyadip Banerjee

IMSc Chennai

Cells often use the Mitogen-Activated Protein Kinase (MAPK) signaling cascade to exhibit a discrete change in their phenotypic behavior for a graded input stimulus. A well-known example of the discrete change is the maturation of Xenopus oocytes cells which change from an immature to a mature state depending on the progesterone level. A discrete cellular state change, as observed in the case of Xenopus oocytes, requires the cascade associated with the cells to have a good response sensitivity, i.e., it should be able to detect clearly whether a stimulus is above or below a threshold level. Although the cascade's sensitivity is observed to improve with the number of double (de)phosphorylation steps associated with the cascade, it is relatively less clear why the number of such steps is restricted, for instance, to two. In this talk, I will explain how the restriction can result from a drop in information flow with an increase in the number of double (de)phosphorylation steps for a cascade operating at a low protein abundance.