De novo design and construction of an inducible gene expression system in mammalian cells

Inducible expression systems represent the founding technology for the emergence of synthetic biology in mammalian cells. The core molecules in these systems are bacterial regulator proteins that bind to or dissociate from a cognate DNA operator sequence in response to an exogenous stimulus like a small-molecule inducer. In this chapter, we describe a generic protocol of how bacterial regulator proteins can be applied to the design, construction, and optimization of an inducible expression system in mammalian cells. By choosing regulator proteins with an appropriate small-molecule inducer, this protocol provides a straightforward approach for establishing biosensors, cell-to-cell communication systems, or tools to control gene expression in vivo.