A compartmentalized model to directional sensing: How can an amoeboid cell unify pointwise external signals as an integrated entity?

Abstract

After exposure to an external chemical attractant, eukaryotic cells rely on several internal cellular downstream signal transduction pathways to control their chemotactic machinery. These pathways are spatially activated, ultimately leading to symmetry breaking around the cell periphery through the redistribution of various biochemicals such as polymerized actin for propulsion and the assembly of myosin II for retraction, typically at opposite sides of the cell. In this study, we propose a compartment-based design to model this process, known as directional sensing. Our model features a network of excitable elements around the cell circumference that are occasionally stimulated with local colored noise. These elements can share information with their close neighbors. We demonstrate that this dynamic can distinguish a temporary but sufficiently long-lasting direction statistically pointing toward the gradient of external stimulants, which can be interpreted as the preferred orientation of the cell periphery during the directional sensing process in eukaryotes.