{"id":"2c9ff992-566f-57f6-8f40-2fae7558e452","stable_key":"46d15d9e-d3b5-544d-ba01-b785aa3e4f42:b1-slc19a3-pyridoxine-transport","predicate":"mediates","statement":"Human SLC19A3 expression increased pyridoxine uptake at pH 5.5; transport favored acidic over neutral/basic conditions.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"5f5ca26c-8948-52c6-9005-10a6bf1fd077","mechanism_event_label":"The B1 carrier can also carry one B6 form under acidic conditions.","subject":{"id":"4eba176e-17c8-5515-920a-df5d48a40486","slug":"slc19a3","display_name":"Human thiamine transporter 2 / SLC19A3","entity_type_key":"protein"},"object":{"id":"ee31e9c6-9993-5fb0-807a-02933e28a1bc","slug":"cellular-pyridoxine-uptake","display_name":"Cellular pyridoxine uptake","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"5f5ca26c-8948-52c6-9005-10a6bf1fd077","stable_key":"46d15d9e-d3b5-544d-ba01-b785aa3e4f42:b1-slc19a3-pyridoxine-transport-event","event_type":"biochemical_relationship","label":"The B1 carrier can also carry one B6 form under acidic conditions.","description":"Human SLC19A3 expression increased pyridoxine uptake at pH 5.5; transport favored acidic over neutral/basic conditions.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"aa6648f2-8962-5567-9939-ef4145e40ed1","slug":"pyridoxine","display_name":"Pyridoxine","entity_type_key":"small_molecule"},"role":"transport substrate","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"c9e677e1-db84-51e4-8a27-911614687d5f","slug":"slc19a2","display_name":"Human thiamine transporter 1 / SLC19A2","entity_type_key":"protein"},"role":"separately tested transporter","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"4eba176e-17c8-5515-920a-df5d48a40486","slug":"slc19a3","display_name":"Human thiamine transporter 2 / SLC19A3","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ee31e9c6-9993-5fb0-807a-02933e28a1bc","slug":"cellular-pyridoxine-uptake","display_name":"Cellular pyridoxine uptake","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"A pH-dependent shared transport route links B1 and the pyridoxine form of B6.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence-scope","value_text":"Cultured epithelial cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_locator","value_text":"Figures 1-3, 6 and 9","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_spans","value_text":"[{\"source_document\": \"artifacts/thiamine_transport_sources/yamashiro-2020-pyridoxine-source-record.json\", \"source_field\": \"resultList.result[0].abstractText\", \"start_char\": 0, \"end_char\": 1718}]","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human transporter constructs in MDCKII/HEK293 cells; radiotracer uptake at pH 5.5.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"extracellular-pH","value_text":"5.5","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"No systemic B6 transport fraction or supplementation benefit established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Thiamine research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"thiamine","display_name":"Thiamine (vitamin B1)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Human proteins; canine and human cell hosts","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The B1 carrier can also carry one B6 form under acidic conditions.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[yamashiro-2020-pyridoxine] pH-dependent pyridoxine transport by SLC19A2 and SLC19A3: Implications for absorption in acidic microclimates (2020). https://pmc.ncbi.nlm.nih.gov/articles/PMC7863892/ DOI: 10.1074/jbc.RA120.013610","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cultured epithelial cells","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"5564ff13-033e-5aa4-9ef6-63fdf59b8e4a","evidence_kind":"source_excerpt","locator":"Lines 631-645","start_line":631,"end_line":645,"excerpt":"### b1-slc19a3-pyridoxine-transport\nHuman SLC19A3 expression increased pyridoxine uptake at pH 5.5; transport favored acidic over neutral/basic conditions.\nCondition category: normal\nnutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The B1 carrier can also carry one B6 form under acidic conditions.\norganism: Human proteins; canine and human cell hosts\ntissue_or_cell_type: Cultured epithelial cells\nexperimental_model: Human transporter constructs in MDCKII/HEK293 cells; radiotracer uptake at pH 5.5.\nlimitations: No systemic B6 transport fraction or supplementation benefit established.\ncross_nutrient: A pH-dependent shared transport route links B1 and the pyridoxine form of B6.\nevidence_spans: [{\"source_document\": \"artifacts/thiamine_transport_sources/yamashiro-2020-pyridoxine-source-record.json\", \"source_field\": \"resultList.result[0].abstractText\", \"start_char\": 0, \"end_char\": 1718}]\nevidence_locator: Figures 1-3, 6 and 9\nextracellular-pH: 5.5\nevidence-scope: Cultured epithelial cells\n[yamashiro-2020-pyridoxine] pH-dependent pyridoxine transport by SLC19A2 and SLC19A3: Implications for absorption in acidic microclimates (2020). https://pmc.ncbi.nlm.nih.gov/articles/PMC7863892/ DOI: 10.1074/jbc.RA120.013610","model_system":"Human transporter constructs in MDCKII/HEK293 cells; 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Study references: [yamashiro-2020-pyridoxine] pH-dependent pyridoxine transport by SLC19A2 and SLC19A3: Implications for absorption in acidic microclimates (2020). https://pmc.ncbi.nlm.nih.gov/articles/PMC7863892/ DOI: 10.1074/jbc.RA120.013610","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"158d2c03-ac8c-589f-8270-c468165ae346","stable_key":"import-46d15d9e-d3b5-544d-ba01-b785aa3e4f42","title":"Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"f376512fb3310141315548015b387833e3af45146e73fb73cd02cee20e4ddb9c","revision_id":"53bc5eda-dec8-58cc-a56f-a9eb4ab036ef","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}