Regulation of mRNA translation by a photoriboswitch

Optogenetic tools have revolutionized the study of receptor-mediated processes, but such tools are lacking for RNA-controlled systems. In particular, light-activated regulatory RNAs are needed for spatiotemporal control of gene expression. To fill this gap, we usedin vitroselection to isolate a novel riboswitch that selectively binds thetrans isoform of a stiff-stilbene (amino-tSS) –a rapidly and reversibly photoisomerizing small molecule. Structural probing revealed that the RNA binds amino-tSS about 100-times stronger than thecisphotoisoform (amino-cSS).In vitroandin vivofunctional analysis showed that the riboswitch, termed Werewolf-1 (Were-1), inhibits translation of a downstream open reading frame when bound to amino-tSS. Photoisomerization of the ligand with a sub-millisecond pulse of light induced the protein expression. In contrast, amino-cSS supported protein expression, which was inhibited upon photoisomerization to amino-tSS. Reversible photoregulation of gene expression using a genetically encoded RNA will likely facilitate high-resolution spatiotemporal analysis of complex RNA processes.
Source: eLife - Category: Biomedical Science Tags: Biochemistry and Chemical Biology Source Type: research