Conjugation of NAD-capped RNAs to proteins by ADP-ribosyltransferases to generate RNA therapeutics

Background: We discovered that NAD-capped RNAs can be covalently attached to specific target proteins by the phage T4 ADP-ribosyltransferase (ART) ModB, which we term RNAylation.Scientific problem: RNA therapy has almost limitless yet unexplored potential.

Its translation into the clinics, however, requires optimal RNA delivery with high RNA stability, efficient cellular internalisation and precise target affinity. Hypothesis: Protein-RNA interactions are ubiquitous and central in biological control.

I hypothesise that conjugating a NAD-capped nucleic acid to a protein catalysed by an ART generates a novel biomolecule – the RNAylated protein – with unique functionalities.

The covalently linked protein or nucleic acid can trigger a directed intracellular delivery, where both, the protein and the nucleic acid, can become functionally active. This allows targeted modulation of translation or transcription, or editing.

RNAylated proteins may provide a platform to engineer the cell and represent a starting point for the creation of next generation RNA therapeutics.Objectives:This project aims to establish RNAylated proteins as a fundamentally novel tool to regulate cellular processes. In objective 1, we will define the design principles for RNAylated proteins, allowing to control cellular processes.

In objective 2, we will develop delivery strategies to transfer RNAylated proteins in specific cell types and allow for precise cellular localisation.

In objective 3, we will combine the design and delivery principles for RNAylated proteins and apply them to target the tumour suppressor protein p53 by regulating translation, transcription or by editing.Impact: This project will develop RNAylated proteins as next generation RNA therapeutics and deepen our understanding of how a fundamental scientific discovery –the RNAylation of proteins, catalysed by the T4 ART ModB – can be translated into an application.