Project description:Pseudouridine (Ψ) is an ubiquitous RNA modification, present in the tRNAs and rRNAs of species across all domains of life. Conserved pseudouridine synthases modify the mRNAs of diverse eukaryotes, but the modification has yet to be identified in bacterial mRNAs. Here, we report the discovery of pseudouridines in mRNA from E. coli. By testing the mRNA modification capacity of all 11 known pseudouridine synthases, we identify RluA as the predominant mRNA-modifying enzyme, modifying the majority of high-confidence sites.
Project description:Pseudouridine (Ψ) is an ubiquitous RNA modification, present in the tRNAs and rRNAs of species across all domains of life. Conserved pseudouridine synthases modify the mRNAs of diverse eukaryotes, but the modification has yet to be identified in bacterial mRNAs. Here, we report the discovery of pseudouridines in mRNA from E. coli. By testing the mRNA modification capacity of all 11 known pseudouridine synthases, we identify RluA as the predominant mRNA-modifying enzyme, modifying the majority of high-confidence sites.
Project description:Pseudouridine (Ψ) is the most abundant RNA modification, yet little is known about its content, dynamics and function in mRNA and ncRNA. Here, we perform quantitative MS analysis and develop CAP-seq for transcriptome-wide Ψ profiling. The unexpected high Ψ content (Ψ/U ratio: ~ 0.2% to 0.6%) indicates that pseudouridylation in mammalian mRNA is much more prevalent and comprehensive than previously believed. In concordance, CAP-seq identified 2,084 Ψ sites within 1,929 human transcripts. We prove four previously unknown Ψ sites in rRNA and EEF1A1 mRNA. Genetic and biochemical analysis uncover PUS1 as a major human mRNA Ψ synthase. In response to stimuli, Ψ level and sites are dynamically modulated in stimulus-specific manners. Comparisons between human and mouse pseudouridylation reveal conserved and unique sites across tissue and species. We observe stop codon pseudouridylation and readthrough events simultaneously for HSPB1 mRNA, indicating a role in nonsense suppression. Together, these approaches allow in-depth analysis of transcriptome-wide pseudouridylation events and our comprehensive study provides a resource for functional studies of Ψ-mediated epigenetic regulation. Here we report a transcriptome-wide profiling method that utilizes a chemically synthesized N3-CMC, which pre-enriches the Ψ-containing RNAs and blocks the reverse transcription.Mapping the Ψ sites in human transcriptome was performed using HEK293T and PUS1 dependent Ψ sites were identified by comparing PUS1 knock out cells with wildtype cells. Stress inducible or suppressed Ψ sites were identified by comparing stress treated cells with untreated cells. And mouse brain and liver were used to map Ψ sites in mouse transcriptome.
Project description: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.
Project description: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.
Project description:Pseudo-seq was used to measure differences in the extent of pseudouridine (Ψ) modification in rRNA from mice haploinsufficient for the H/ACA biogenesis factor Naf1 compared to wild- type. We measured telomerase RNA levels as well as a sample of box H/ACA RNAs and found they were all decreased in Naf1+/- mice. Nevertheless, Naf1+/- mice had minimally decreased levels of pseudouridylation at the rRNA sites queried. This was not associated with any phenotypic abnormalities in vivo in these mice which we examined for hematopoeitic, liver, testes and brain defects. CMC treatment of RNA followed by next generation sequencing was used to measure the extent of pseudouridylation at mapped mouse rRNA Ψ sites.