{"id":"12e5e545-a3ed-5db9-a9d7-a9f2c2b59288","stable_key":"066fc1e8-fefc-5be0-9905-938b10b89691:vapb-ko-mito-iron","predicate":"has_contextual_experimental_effect","statement":"VAPB knockout reduced total iron measured in isolated HeLa mitochondria.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"7169847c-95b3-5836-bb1b-b069bf294710","mechanism_event_label":"vapb ko mito iron","subject":{"id":"3d7cdc2a-737d-58ee-8ed4-385b1f76b9e2","slug":"human-vapb-knockout-hela","display_name":"VAPB knockout in HeLa cells","entity_type_key":"protein_state"},"object":{"id":"e2084fd0-e763-5b6a-bf64-f4010a8442d4","slug":"human-mitochondrial-total-iron","display_name":"Total iron in isolated human-cell mitochondria","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"7169847c-95b3-5836-bb1b-b069bf294710","stable_key":"066fc1e8-fefc-5be0-9905-938b10b89691:vapb-ko-mito-iron","event_type":"experimental_result","label":"vapb ko mito iron","description":"VAPB knockout reduced total iron measured in isolated HeLa mitochondria.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"3d7cdc2a-737d-58ee-8ed4-385b1f76b9e2","slug":"human-vapb-knockout-hela","display_name":"VAPB knockout in HeLa cells","entity_type_key":"protein_state"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e2084fd0-e763-5b6a-bf64-f4010a8442d4","slug":"human-mitochondrial-total-iron","display_name":"Total iron in isolated human-cell mitochondria","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"role":"measured element","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"access_level","value_text":"selected_primary_main_text_and_legends; cached web/indexed passages, not complete supplement review","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_cache","value_text":"artifacts/discovery-research/round4-sources/s41556-026-01974-0-web.json; SHA256 6971539ed35950faaf1931771badfd7fbad98541e4ffcb56177e63be586de40a","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"HeLa; MERBiT reporter derivative where stated","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Stable CRISPR knockout; ICP-MS after digestion; pg metal per microgram mitochondrial protein; three independent experiments","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Selected primary main-text Results and figure legends reviewed; supplementary images not independently inspected. These two papers share authors and are not independent replication. They do not test whether SLC25A39-loss-induced contacts increase HMOX2-dependent iron delivery. ICP-MS measures total iron, not labile iron or transport flux. Contact loss affecting an outcome does not establish that increasing contacts increases it. Ubiquitination/activity readouts do not establish direct enzymatic activation or the outer-membrane iron transport machinery. 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These two papers share authors and are not independent replication. They do not test whether SLC25A39-loss-induced contacts increase HMOX2-dependent iron delivery. ICP-MS measures total iron, not labile iron or transport flux. Contact loss affecting an outcome does not establish that increasing contacts increases it. Ubiquitination/activity readouts do not establish direct enzymatic activation or the outer-membrane iron transport machinery. 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