Characterization of an optogenetic translation activation system

Considerable work has focused on developing systems to control cellular events using light, which is nontoxic to most mammalian cells and can be delivered with spatiotemporal control. We have developed a genetically encoded optogenetic system in which blue light activates target mRNA translation in mammalian cells. Specifically, we used blue light to induce the reconstitution of an RNA binding domain and a translation initiation domain, thereby activating target mRNA translation downstream of binding sites. We found that the influence of the ratio of the amount of reporter plasmid to that of effector plasmid on translation activation is small, which demonstrates the robustness of system to plasmid amounts. We also found that increasing the number of binding sites (aptamers) on the target mRNA enhanced translation activation in a light-sensitive manner.