{"id":"39f120d8-3251-5766-b7a8-864dabd80c64","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-rfvt3-substrate-discrimination","predicate":"preferentially-transports","statement":"RFVT3-expressing HEK293 cells transported riboflavin strongly, FMN weakly, and showed no measurable FAD transport in the reported assay.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"cf6bd1d6-96f2-59ba-94bb-a01a505c9d0f","mechanism_event_label":"Free riboflavin was the preferred transported flavin.","subject":{"id":"036b3828-9ad7-5a41-9e89-119cef5c3665","slug":"slc52a3","display_name":"Riboflavin transporter 3 / SLC52A3","entity_type_key":"protein"},"object":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"cf6bd1d6-96f2-59ba-94bb-a01a505c9d0f","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-rfvt3-substrate-discrimination-event","event_type":"biochemical_relationship","label":"Free riboflavin was the preferred transported flavin.","description":"RFVT3-expressing HEK293 cells transported riboflavin strongly, FMN weakly, and showed no measurable FAD transport in the reported assay.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"036b3828-9ad7-5a41-9e89-119cef5c3665","slug":"slc52a3","display_name":"Riboflavin transporter 3 / SLC52A3","entity_type_key":"protein"},"role":"transporter","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"role":"preferred-substrate","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"d3eacf85-1a35-546d-bd30-161474dd9691","slug":"fmn","display_name":"Flavin mononucleotide","entity_type_key":"small_molecule"},"role":"weak-substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"e2cd7179-f218-54e8-9ce9-7a836ae35fac","slug":"fad","display_name":"FAD","entity_type_key":"small_molecule"},"role":"tested-nonsubstrate","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_location","value_text":"Figure 3C-E","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"HEK293 expression; HPLC measurement of flavin uptake","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"10 micromolar flavin, pH 7.4, 10 minutes, 37 C.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Substrate preference under these conditions is not proof of zero FMN transport at every concentration.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Riboflavin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Free riboflavin was the preferred transported flavin.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[transport-rfvt3-2014] Functional involvement of RFVT3/SLC52A3 in intestinal riboflavin absorption. (2014). https://doi.org/10.1152/ajpgi.00349.2013 DOI: 10.1152/ajpgi.00349.2013","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"HEK293 cells","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"00ef205e-df1a-514c-a36d-53b1a8795d3c","evidence_kind":"source_excerpt","locator":"Lines 228-239","start_line":228,"end_line":239,"excerpt":"### transport-rfvt3-substrate-discrimination\nRFVT3-expressing HEK293 cells transported riboflavin strongly, FMN weakly, and showed no measurable FAD transport in the reported assay.\nCondition category: normal\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Free riboflavin was the preferred transported flavin.\norganism: Homo sapiens\ntissue_or_cell_type: HEK293 cells\nexperimental_model: HEK293 expression; HPLC measurement of flavin uptake\nlimitations: Substrate preference under these conditions is not proof of zero FMN transport at every concentration.\nexposure: 10 micromolar flavin, pH 7.4, 10 minutes, 37 C.\nevidence_location: Figure 3C-E\n[transport-rfvt3-2014] Functional involvement of RFVT3/SLC52A3 in intestinal riboflavin absorption. 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