Constructive effects of noise on cell signaling in bistable map kinase cascades

Cell signaling is naturally subject to random fluctuations arising not only from the external environment but also from the intracellular molecular reactions. How the fluctuations are exploited by a single cell to regulate its signaling transduction pathways, such as mitogen-activated protein kinase (MAPK) cascades, has not yet been well understood. In this article, based on a recently proposed model for reaction-diffusion MAPK cascades, we investigate the constructive effects of noises in cell signaling transduction pathways. For a spherical cell, we found that both extracellular and intracellular noises can facilitate phosphoprotein waves propagation from the plasma membrane to the periphery of cell nucleus, and thus a spatial gradient of biphosphorylated MAPK occurs. The results presented here suggest that noises could be exploited by living organisms for cellular decision-making processing.