Société Française de Biochimie et Biologie Moléculaire

Farrah BOUHEDDA - APRIL 2020

Strasbourg Univ., CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France 

" A dimerization-based fluorogenic dye-aptamer module for RNA imaging in live cells" 

Nature Chemical Biology 16,69-76 (2020) http:// doi:10.1038/s41589-019-0381-8Bouhedda, F., Fam, K.T., Collot, M., Autour, A., Marzi, S., Klymchenko, A., Ryckelynck, M.



Farrah Bouhedda, 26 obtained a master's degree in molecular and cellular biology in 2016 with the specialty "biology and molecular genetics" at the University of Strasbourg. Passionate  about the field of molecular biology and biotechnology, she is currently performing a doctorate under the supervision of Michael Ryckelynck (IBMC, CNRS, University of Strasbourg). During her thesis, she is interested in the development of new RNA imaging tools using an ultra-high throughput screening strategy called droplet based-microfluidics. These imaging tools named "light-up aptamers" are RNA molecules capable of specifically recognizing a fluorophore and activate strongly its fluorescence. Among her various work, Farrah Bouhedda and her collaborators have thus combined their know-how to develop a new fluorescent probe for RNA imaging, orange in color. "o-Coral / Gemini - 561 "showing promising features for the study of RNA functions and dynamics in mammalian cells.

Article Summury

Live-cell imaging of RNA has remained a challenge because of the lack of naturally fluorescent RNAs. Recently developed RNA aptamers that can light-up small fluorogenic dyes could overcome this limitation, but they still suffer from poor brightness and photostability. Here, we propose the concept of a cell-permeable fluorogenic dimer of self-quenched sulforhodamine B dyes (Gemini-561) and the corresponding dimerized aptamer (o-Coral) that can drastically enhance performance of the current RNA imaging method. The improved brightness and photostability, together with high affinity of this complex, allowed direct fluorescence imaging in live mammalian cells of RNA polymerase III transcription products as well as messenger RNAs labeled with a single copy of the aptamer; that is, without tag multimerization. The developed fluorogenic module enables fast and sensitive detection of RNA inside live cells, while the proposed design concept opens the route to new generation of ultrabright RNA probes.