{"id":"f2affd47-c833-5cbd-8161-f37a54c653a9","stable_key":"research:ftsj1-um34","predicate":"catalyzes_modification_to","statement":"FTSJ1 catalyzes Sec-tRNA U34 ribose methylation producing the Um34-containing form.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"literature_reviewed:direct_experimental","direction":"positive","is_public":true,"mechanism_event_id":"477fed9e-cc61-5ce3-8a0a-92c2a2510bd6","mechanism_event_label":"FTSJ1 is the enzyme for the formerly unassigned methylation step.","subject":{"id":"093683ad-836f-5f4e-8822-ea7915a38f52","slug":"ftsj1","display_name":"FTSJ1","entity_type_key":"protein"},"object":{"id":"028e853c-7b1d-5be4-acdd-1c6a84a81b98","slug":"mcm5um34","display_name":"mcm5Um34","entity_type_key":"rna_modification"},"evidence_count":1,"mechanism_event":{"id":"477fed9e-cc61-5ce3-8a0a-92c2a2510bd6","stable_key":"research:ftsj1-um34","event_type":"rna_modification","label":"FTSJ1 is the enzyme for the formerly unassigned methylation step.","description":"FTSJ1 catalyzes Sec-tRNA U34 ribose methylation producing the Um34-containing form.","status":"active","compartment":null,"participants":[{"entity":{"id":"093683ad-836f-5f4e-8822-ea7915a38f52","slug":"ftsj1","display_name":"FTSJ1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"028e853c-7b1d-5be4-acdd-1c6a84a81b98","slug":"mcm5um34","display_name":"mcm5Um34","entity_type_key":"rna_modification"},"role":"object","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"cell_type","value_text":"Melanoma cells and biochemical systems","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Biochemistry, human melanoma cells and mouse metastasis/xenograft models","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"FTSJ1 deletion is not ordinary dietary selenium deficiency.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a559820f-aedd-5a97-ac29-de0a2d35a7f9","evidence_kind":"curated_literature_summary","locator":"lines 1191-1201","start_line":1191,"end_line":1201,"excerpt":"## ftsj1-um34\n\nFTSJ1 is the enzyme for the formerly unassigned methylation step.\n\nFTSJ1 catalyzes Sec-tRNA U34 ribose methylation producing the Um34-containing form.\n\nOrganism: Homo sapiens\nCell type: Melanoma cells and biochemical systems\nExperimental model: Biochemistry, human melanoma cells and mouse metastasis/xenograft models\nLimitations: FTSJ1 deletion is not ordinary dietary selenium deficiency.\nPrimary reference: [Selenocysteine tRNA methylation promotes oxidative stress resistance in melanoma metastasis](https://www.nature.com/articles/s43018-024-00844-8)","model_system":"Biochemistry, human melanoma cells and mouse metastasis/xenograft models","directness":"author_interpretation","verification_status":"secondary_verified","notes":"Curated summary; inspect the linked primary papers for original methods and results.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f892f13-06ea-5199-a33c-a703f35c80ae","stable_key":"selenium-research-2026-09-17","title":"Selenium: literature corrections and mechanism additions","document_type":"curated_literature_review","citation_label":"Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually","file_path":"","sha256":"0b818b10c1c7120e5caf7f4d4019d7bd025d745692e424f515d3ef903c9ab7f3","revision_id":"80984e03-5f0f-5877-8094-afef7637444e","review_status":"secondary_verified","notes":"Secondary curated summaries of primary experiments, with explicit models and limitations. Not archived primary full text."}}],"relations":[],"conflicts":[],"corrections":[{"id":"de957c1a-6439-5dd3-8149-06027ad575d5","title":"The formerly unassigned Um34 enzyme is identified as FTSJ1","kind":"contradiction","status":"corrected","why":"The earlier correction table lists the Um34 methylation enzyme as unassigned. The new reference identifies FTSJ1 and cites the 2024 experimental study.","resolution":"Record FTSJ1 as the identified tRNA[Ser]Sec Um34 methyltransferase, while keeping the earlier passage as a dated knowledge state and avoiding a nutritional diagnosis from FTSJ1 loss.","created_at":"2026-09-17 05:59:32","record_type":"correction","display_label":"Correction history","record_url":"/corrections/de957c1a-6439-5dd3-8149-06027ad575d5","literature_review":{"revision_id":"80984e03-5f0f-5877-8094-afef7637444e","start_line":1549,"end_line":1554,"papers":[{"paper_key":"nease-2024","title":"Selenocysteine tRNA methylation promotes oxidative stress resistance in melanoma metastasis","url":"https://www.nature.com/articles/s43018-024-00844-8","doi":"10.1038/s43018-024-00844-8","year":2024,"model":"Biochemistry, human melanoma cells and mouse metastasis/xenograft models","summary":"Identifies FTSJ1 as the Sec-tRNA Um34 methyltransferase."}]},"sides":[{"conflict_id":"de957c1a-6439-5dd3-8149-06027ad575d5","ordinal":0,"label":"Earlier statement","revision_id":"4cec6304-35d7-5560-9133-e6ea689db838","start_line":153,"end_line":157,"quote":"| Position Mark Made by  |                        |                             |\n| ---------------------- | ---------------------- | --------------------------- |\n| A37                    | **i⁶A** (isopentenyl)  | TRIT1                       |\n| U34                    | cm⁵U → **mcm⁵U**       | Elongator (ELP1–6) → ALKBH8 |\n| U34 ribose             | **Um34** (2′-O-methyl) | the last unassigned step    |","claim_id":null,"source_key":"corrections","source_title":"Selenium corrections and deep dive","claim_ids":[]},{"conflict_id":"de957c1a-6439-5dd3-8149-06027ad575d5","ordinal":1,"label":"New reference qualification","revision_id":"f8f97804-c1fb-56df-9c06-c02e36e2a5b8","start_line":73,"end_line":75,"quote":"Disrupting upstream tRNA modification in experimental models can selectively reduce proteins such as GPX1 and SELENOW while relatively preserving others. The exact dependency is protein- and model-specific, not a universal ranking of all ~25 human selenoproteins.\n\nUpdate: FTSJ1 was identified in 2024 as the tRNA^[Ser]Sec Um34 methyltransferase. Loss of FTSJ1 reduced efficient Sec insertion and sensitized experimental cells to oxidative stress. Evidence: cell/biochemical and melanoma xenograft models. [1]","claim_id":null,"source_key":"deficiency","source_title":"Selenium deficiency: a mechanism-first reference","claim_ids":[]}]}],"research":{"topic":"Selenium scientific audit","plain_language":"FTSJ1 is the enzyme for the formerly unassigned methylation step.","evidence_scope":"direct_experimental","papers":[{"key":"nease-2024","title":"Selenocysteine tRNA methylation promotes oxidative stress resistance in melanoma metastasis","url":"https://www.nature.com/articles/s43018-024-00844-8","doi":"10.1038/s43018-024-00844-8","year":2024,"model":"Biochemistry, human melanoma cells and mouse metastasis/xenograft models","summary":"Identifies FTSJ1 as the Sec-tRNA Um34 methyltransferase."}]}}