Design, Analysis and Simulation of a Polarity Module for Chemokine Sensing

Chemotaxis describes a number of mechanisms by which living organismsnavigate a concentration field, allowing them for exampleto migrate towards a molecule source. In amoeboid chemotaxis, theexternal concentration signal must first be converted to an intracellularone, which modulates cell crawling. Typically, the leadingedge of the cell forms protrusions and adheres to their adjacentsurfaces, while the trailing edge contracts and detaches from surfaces.Therefore, first a polarity with respect to the extracellularsignal has to be established to define what leading and trailing edgeactually is. In this paper we develop a chemical reaction networkthat is capable of generating the respective polarity signal over thewide range of concentration levels typically observed in biologicalsignaling. Based on the system’s equilibrium, we derive designguidelines for the network and verify them by dynamic simulationsof the overall system.