edu-Ψ-seq Reveals snoRNA-guided mRNA Pseudouridylation that Regulates Protein Synthesis

Purpose:Pseudouridine (Ψ) is the most abundant RNA epigenetic modification and plays vital roles in various biological processes. However, its biogenesis and functions in mRNAs remain elusive. Method:Here, we developed an approach for enriching Ψ sites with deep sequencing (edu-Ψ-seq), which utilizes both exoribonuclease and restriction endonuclease activity to eliminate other nucleosides or reads without Ψ modifications. Results:Using edu-Ψ-seq approach in the dyskerin pseudouridine synthase 1 (DKC1) knockdown cells, we identified that more than 100 pseudouridines could be catalyzed by DKC1 in human mRNAs and non-coding RNAs (ncRNAs). Surprisingly, we discovered, for the first time, 10 pseudouridines in mRNAs might be guided by 11 small nucleolar ncRNAs (snoRNAs). Interestingly, we found that SNORA10 could guide DKC1 protein to induce the pseudouridylation of RPL15 mRNA. Importantly, loss of SNORA10 impaired the protein synthesis of RPL15 and inhibited cell proliferation. Conclusion:Overall, our study not only developed a powerful method for detecting Ψ sites but also uncovered another layer of gene expression regulation that involves crosstalk among snoRNAs, mRNA pseudouridylation and protein synthesis.