Protease-based synthetic sensing and signal amplification

Abstract

Significance Synthetic biology envisages the creation of custom-based signaling by means of modular plug-and-play. This concept has primarily been realized in the construction of synthetic gene circuits. However, all real-time events in biology are processed by protein-based sensing and signal transducing systems; yet, the systematic bottom-up design of protein-based signaling systems remains elusive to date. Here we report a strategy for construction of modular protein switches based on artificially autoinhibited proteases whose activity can be modulated by specific proteolysis, ligand binding, or protein–protein interactions. We demonstrate that such protease-based ligand receptors or signal transducers can be assembled into different types of integrated signal sensing and amplification circuits that, in principle, can be connected to any biological process.