{"doi":"10.1261/rna.080315.124","title":"<i>Schizosaccharomyces pombe pus1</i>mutants are temperature sensitive due to decay of tRNA<sup>Ile(UAU)</sup>by the 5′-3′ exonuclease Dhp1, primarily targeting the unspliced pre-tRNA","abstract":"The pseudouridylase Pus1 catalyzes pseudouridine (Ψ) formation at multiple uridine residues in tRNAs, and in some snRNAs and mRNAs. Although Pus1 is highly conserved, and mutations are associated with human disease, little is known about eukaryotic Pus1 biology. Here, we show that Schizosaccharomyces pombe pus1 Δ mutants are temperature sensitive due to decay of tRNA Ile(UAU) , as tRNA Ile(UAU) levels are reduced, and its overexpression suppresses the defect. We show that tRNA Ile(UAU) is degraded by the 5′-3′ exonuclease Dhp1 (ortholog of Saccharomyces cerevisiae Rat1), as each of four spontaneous pus1 Δ suppressors had dhp1 mutations and restored tRNA Ile(UAU) levels, and two suppressors that also restored tRNA Ile(UAU) levels had mutations in tol1 ( S. cerevisiae MET22 ortholog), predicted to inhibit Dhp1. We show that Pus1 modifies U 27 , U 34 , and U 36 of tRNA Ile(UAU) , raising the question about how these modifications prevent decay. Our results suggest that Dhp1 targets unspliced pre-tRNA Ile(UAU) , as a pus1 Δ strain in which the only copy of tRNA Ile(UAU) has no intron [ tI(UAU)-i Δ] is temperature resistant and undergoes no detectable decay, and the corresponding pus1 Δ tI(UAU)-WT strain accumulates unspliced pre-tRNA Ile(UAU) . Moreover, the predicted exon–intron structure of pre-tRNA Ile(UAU) differs from the canonical bulge–helix–loop structure compatible with tRNA splicing, and a pus1 Δ tI(UAU)i-var strain with intron mutations predicted to improve exon–intron structure is temperature resistant and undergoes little decay. These results suggest that decay of tRNA Ile(UAU) by Dhp1 in pus1 Δ strains occurs at the level of unspliced pre-tRNA Ile(UAU) , implying a substantial role for one or more of the Ψ residues in stabilizing the pre-tRNA structure for splicing.","journal":"RNA","year":2025,"id":540172,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9584,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1170416,"name":"Erin Marcus","orcid":null,"position":1,"is_corresponding":false},{"id":1428336,"name":"Savanah Neupert","orcid":null,"position":2,"is_corresponding":false},{"id":1134208,"name":"Sarah M. Ostrowski","orcid":"0000-0002-9129-3528","position":3,"is_corresponding":false},{"id":97947,"name":"David H. Mathews","orcid":"0000-0002-2907-6557","position":4,"is_corresponding":false},{"id":458454,"name":"Eric M. Phizicky","orcid":"0000-0002-5095-6583","position":5,"is_corresponding":false},{"id":1233866,"name":"Franziska Stegemann","orcid":"0000-0002-7721-8329","position":0,"is_corresponding":true}],"reference_count":107,"raw_metadata":null,"created_at":"2026-07-19T02:52:38.861025Z","pmid":"39848696","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}