RNA Switch Activates Fluorescent Dye in Live-Cell Imaging

Researchers have uncovered the precise mechanism that powers RhoBAST, a minimal RNA construct that activates fluorescent dyes for super‑resolution imaging of RNA in living cells. The study, led by Ronald Micura and colleagues at the Institute of Organic Chemistry, demonstrates that a localized “nucleotide flip” within the RNA sequence triggers the dye’s fluorescence. This finding clarifies how the tiny RNA scaffold converts a chemical signal into a bright, trackable signal, enabling scientists to monitor RNA dynamics with unprecedented spatial detail.

The international collaboration combined structural biology, photophysics, and computational modeling to pinpoint the conformational change responsible for dye activation. By mapping the flip at the single‑nucleotide level, the team showed that the RNA’s tertiary architecture is finely tuned to control dye binding and emission. These insights provide a blueprint for designing next‑generation RNA‑based probes that can be tailored for specific cellular targets and imaging modalities.

With the mechanism now understood, the RhoBAST platform can be refined for broader applications in molecular biology and diagnostics. The ability to track individual RNA molecules in real time opens new avenues for studying gene expression, RNA‑protein interactions, and the cellular response to therapeutics, marking a significant step forward in live‑cell imaging technology.