title: TRUB1 is the predominant pseudouridine synthase acting on mammalian mRNA via a predictable and conserved code.
abstract: Following synthesis, RNA can be modified with over 100 chemically distinct modifications, which can potentially regulate RNA expression post-transcriptionally. Pseudouridine (Ψ) was recently established to be widespread and dynamically regulated on yeast mRNA, but less is known about Ψ presence, regulation, and biogenesis in mammalian mRNA. Here, we sought to characterize the Ψ landscape on mammalian mRNA, to identify the main Ψ-synthases (PUSs) catalyzing Ψ formation, and to understand the factors governing their specificity toward selected targets. We first developed a framework allowing analysis, evaluation, and integration of Ψ mappings, which we applied to >2.5 billion reads from 30 human samples. These maps, complemented with genetic perturbations, allowed us to uncover TRUB1 and PUS7 as the two key PUSs acting on mammalian mRNA and to computationally model the sequence and structural elements governing the specificity of TRUB1, achieving near-perfect prediction of its substrates (AUC = 0.974). We then validated and extended these maps and the inferred specificity of TRUB1 using massively parallel reporter assays in which we monitored Ψ levels at thousands of synthetically designed sequence variants comprising either the sequences surrounding pseudouridylation targets or systematically designed mutants perturbing RNA sequence and structure. Our findings provide an extensive and high-quality characterization of the transcriptome-wide distribution of pseudouridine in human and the factors governing it and provide an important resource for the community, paving the path toward functional and mechanistic dissection of this emerging layer of post-transcriptional regulation.
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Modi
authors.initials: M
authors.lastname: Safra
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Ronit
authors.initials: R
authors.lastname: Nir
authors.affiliation: Broad Institute, Cambridge, Massachusetts 02142, USA.
authors.forename: Daneyal
authors.initials: D
authors.lastname: Farouq
authors.affiliation: Department of Computer Science and Applied Math, Weizmann Institute of Science, Rehovot 76100, Israel.|Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Ilya
authors.initials: I
authors.lastname: Vainberg Slutskin
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Schraga
authors.initials: S
authors.lastname: Schwartz
mesh_terms: D000818:Animals; D017124:Conserved Sequence; D057809:HEK293 Cells; D006801:Humans; D019751:Intramolecular Transferases / Q000378:metabolism*; D051379:Mice; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D019751:Intramolecular Transferases; C096995:pseudouridine synthases