Eukaryotic artificial ON-riboswitches that respond efficiently to mid-sized short peptides

We chose two types of mid-sized Arg-rich peptides (Rev-pep and Tat-pep) as ligands and used their aptamers to construct efficient eukaryotic ON-riboswitches (ligand-dependently upregulating riboswitches). Due to the aptamers' high affinities, the best Rev-pep-responsive and Tat-pep-responsive riboswitches obtained showed much higher switching efficiencies at low ligand concentrations than small ligand-responsive ON-riboswitches in the same mechanism. In addition, despite the high sequence similarity of Rev-pep and Tat-pep, the two best riboswitches were almost insensitive to each other's peptide ligand. Considering the high responsiveness and specificity along with the versatility of the expression platform used and the applicability of Arg-rich peptides, this orthogonal pair of riboswitches would be widely useful eukaryotic gene regulators or biosensors.

Automated summary

This study constructed efficient eukaryotic ON-riboswitches using high-affinity aptamers of mid-sized Arg-rich peptides. These riboswitches showed higher switching efficiencies at low ligand concentrations compared to small ligand-responsive ON-riboswitches. Additionally, the two best riboswitches were almost insensitive to each other's peptide ligands despite their high sequence similarity. This orthogonal pair of riboswitches could serve as widely useful eukaryotic gene regulators or biosensors due to their high responsiveness and specificity.