Abstract

Messenger RNAs (mRNAs) enable the production of almost any functional protein/peptide in the human body as a vaccine or therapeutic agent. The translation of mRNA is a fundamental process in gene expression, and controlling translation is crucial for regulating the production of proteins in cells. However, one cannot control when and where mRNA is translated into protein, which then has a pharmacological effect. We developed 5′ cap analogues with photo-cleavable groups (FlashCaps) that prohibit binding to the eukaryotic translation initiation factor eIF4E and resist cleavage by decapping enzymes.1 These compounds are compatible with the general and efficient production of mRNAs by in vitro transcription. The single photocaging group in FlashCap-mRNAs prevents translation in mammalian cells and in vitro while not raising immunogenicity. The native cap is restored by irradiation, resulting in effective translation. FlashCaps overcome the problem of remaining sequence or structure changes in mRNA after irradiation that limited previous designs. By combining 5′ cap analogs with photo-cleavable groups based on coumarin or ortho-nitrobenzyl moieties, multiplexing for two distinct mRNAs was accomplished.2 Alternative enzymatic routes to photocage mRNAs will be discussed.3,4 Our results demonstrate that FlashCaps offer a route to regulate the expression of any given mRNA and to dose mRNA therapeutics with spatio-temporal control. References [1] N. Klocker, F. P. Weissenboeck, M. van Dulmen, P. Spacek, S. Huwel and A. Rentmeister, Nat Chem 2022, 14, 905-913. [2] A. Bollu, N. Klöcker, P. Špaček, F. P. Weissenboeck, S. Hüwel and A. Rentmeister, Angew Chem Int Ed 2023, 62, e202209975. [3] L. Anhäuser, N. Klöcker, F. Muttach, F. Mäsing, P. Špaček, A. Studer and A. Rentmeister, Angew Chem Int Ed 2020, 59, 3161-3165. [4] N. Klöcker, L. Anhäuser and A. Rentmeister, ChemBioChem 2022, 23, e202100437.