LAUSR

Nonlinear dynamics in synthetic biology systems, generated as a consequence of interconnections between biological modules, poses challenges to the objective of engineering biological systems with predictable characteristics. Mathematical models, that often provide accurate descriptions of the biological modules in isolation, fail to capture such nonlinearities that arise in the interconnected modules. Without the modelling and quantification of these nonlinearities, systems biology models cannot be predictable or reliable. Hence it become a key area of focus of systems and synthetic biologists. To this end, we analyse the nonlinearities in the SOS response system, a prime cellular network in bacterial cells that functions to repair the DNA damage. It is shown that the dynamics of the modules in the SOS response system differ in isolation and in integration, and substantial variation is observed when more modules are connected. The interdependence among major modules is quantified, which imparts whether the integrated dynamics is an attenuation or amplification of the isolated dynamics. From a synthetic biology perspective, our study contributes to the effective engineering of biological devices from the integration of biological modules in a bottom-up fashion. Meanwhile, it also complements the investigations on the DNA damage repairing mechanism in living cells.