The 'Power Network' of Genetic Circuits

Synthetic biology is an emergent research field whose aim is to engineer gene regulatory networks (GRNs) in living cells for useful functionalities. However, due to the unwanted interactions among nodes and with the cellular “chassis”, behavior of a GRN is often context dependent. One source of context dependence that has received much attention recently is the competition among nodes in a GRN for a limited amount of resources provided by the host cell. In this paper, we review our recent research outcomes on the modeling and mitigation of resource competition in GRNs from a control theoretic perspective. In particular, we demonstrate that resource competition gives rise to hidden interactions among nodes that change the intended network topology. By regarding hidden interactions as disturbances, we formulate a network disturbance decoupling problem that can be solved by implementing decentralized feedback controllers in the nodes. Our results provide examples of how introducing concepts in systems and control theory can lead to solutions to pressing practical problems in synthetic biology.