An RNA-Based Platform for Gene Network Engineering

We have entered the era of whole genome engineering, yet there remain fundamental questions of how to design complex genetic networks that create novel biological function.  Many simple synthetic circuits have been constructed from various natural regulators.  However, this approach suffers from the inherent barriers associated with coordinating increasing numbers of diverse components.  Here we engineered independent, yet functionally identical, copies of a natural antisense-RNA-mediated transcription attenuator and arranged them in networks that performed essential and necessary functions of cellular gene regulation.  We found that attenuator variants can be engineered to independently regulate two genes in the same cell, that tandem attenuators perform genetic logics by a simple multiplication rule, and that attenuators can be connected together in the first example of an RNA-based regulatory cascade.  Our results demonstrate a simplified approach to synthetically creating sophisticated function simply by changing the network topology of independent, yet otherwise identical, components.