Orthogonal optogenetic triple-gene control in mammalian cells

24.10.2014

Müller K, Engesser R, Timmer J, Zurbriggen MD, Weber W

ACS Synth Biol. 2014;3(11):796-801

ACS Synth Biol.         online article

Optogenetic gene switches allow gene expression control at an unprecedented spatiotemporal resolution. Recently, light-responsive transgene expression systems that are activated by UV-B, blue or red light have been developed. These systems perform well on their own, but their integration into genetic networks has been hampered by the overlapping absorbance spectra of the photoreceptors. We identified a lack of orthogonality between UV-B and blue light-controlled gene expression as the bottleneck and employed a model-based approach that identified the need for a blue light-responsive gene switch that is insensitive to low-intensity light. Based on this prediction we developed a blue light-responsive and rapidly-reversible expression system. Finally, we employed this expression system to demonstrate orthogonality between UV-B, blue and red/far-red light responsive gene switches in a single mammalian cell culture. We expect this approach to enable the spatiotemporal control of gene networks and to expand the applications of optogenetics in synthetic biology.