Breaking: CRISPR-CAS13 enables programmable RNA acetylation

This work addressed a significant limitation in RNA research – the inability to selectively acetylate specific transcripts to study ac4C function. Through protein engineering, the team created enhanced NAT10 (eNAT10), a hyperactive variant of the N-acetyltransferase enzyme responsible for ac4C modifications. When fused to catalytically inactive Cas13 (dCas13), this system enables programmable RNA acetylation guided by single-guide RNAs.

The researchers engineered human NAT10 through systematic truncation studies, identifying that removal of C-terminal domains (residues 802–1025) produced the most active variant whilst maintaining substrate specificity. This eNAT10 variant showed 127-fold enrichment compared to full-length NAT10 when targeting reporter transcripts.

The dCas13–eNAT10 fusion demonstrated robust acetylation of both exogenous reporters and endogenous transcripts across multiple cell lines and primary cells, with specificity confirmed through transcriptome-wide analysis.

Single-base resolution mapping revealed that acetylation occurs broadly across targeted transcripts with a strong preference for 5′-CCG-3′ motifs. The system enhanced protein production from acetylated mRNAs by 1.2–1.4-fold, consistent with ac4C's role in translation regulation. Using dual adeno-associated virus delivery, the team successfully demonstrated programmable RNA acetylation in mouse liver tissue, opening possibilities for in vivo applications.

The study was conducted by Jihwan Yu and colleagues at the Korea Advanced Institute of Science and Technology, with Won Do Heo as senior author. The research was published in Nature Chemical Biology on 2 June.