The team at the Korea Advanced Institute of Science and Technology, led by senior author Won Do Heo and spearheaded experimentally by Jihwan Yu and colleagues, overcame a major obstacle in RNA biology: the lack of tools for transcript-specific acetylation of N4-acetylcytidine (ac4C). By engineering a hyperactive variant of the N-acetyltransferase NAT10—termed eNAT10—through systematic C-terminal truncations (removing residues 802–1025), they achieved a version of the enzyme that maintained substrate specificity while exhibiting 127-fold greater activity on reporter transcripts than full-length NAT10.

Fusing this enhanced enzyme to catalytically dead Cas13 (dCas13) created a programmable acetylation platform guided by single-guide RNAs. The dCas13–eNAT10 fusion efficiently acetylated both exogenous reporters and endogenous transcripts across multiple cell lines and primary cells, with transcriptome-wide analyses confirming the method’s specificity.

Single-base resolution mapping revealed broad acetylation of targeted transcripts, with a pronounced preference for 5′-CCG-3′ motifs. Functionally, mRNAs modified by this system produced 1.2- to 1.4-fold more protein, in line with ac4C’s known role in enhancing translation. Extending their work in vivo, the researchers used dual adeno-associated virus vectors to demonstrate programmable RNA acetylation in mouse liver tissue, setting the stage for future therapeutic applications. This study was published on 2 June in Nature Chemical Biology.

Source: https://crisprmedicinenews.com/news/breaking-crispr-cas13-enables-programmable-rna-acetylation