{"id":"3aeba3ca-6015-53db-af52-bce35b62bfde","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:phospho1-in-matrix-vesicles","predicate":"localized_in","statement":"Active PHOSPHO1 was detected inside osteoblast-derived matrix vesicles; phosphoethanolamine hydrolase activity became accessible after vesicle sonication.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"99f4249a-6252-5dad-8c24-cf840da9ab10","mechanism_event_label":"Mineralizing vesicles contain phosphate-generating machinery within their membrane.","subject":{"id":"bb7ed19e-2f65-5951-8963-40d6b3249b71","slug":"phospho1","display_name":"Phosphoethanolamine/phosphocholine phosphatase PHOSPHO1","entity_type_key":"protein"},"object":{"id":"0da3fbd1-7438-5d0a-954d-f059bd3d22a9","slug":"matrix-vesicle","display_name":"Mineralizing matrix vesicle","entity_type_key":"organelle"},"evidence_count":1,"mechanism_event":{"id":"99f4249a-6252-5dad-8c24-cf840da9ab10","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:phospho1-in-matrix-vesicles-event","event_type":"biochemical_relationship","label":"Mineralizing vesicles contain phosphate-generating machinery within their membrane.","description":"Active PHOSPHO1 was detected inside osteoblast-derived matrix vesicles; phosphoethanolamine hydrolase activity became accessible after vesicle sonication.","status":"provisional","compartment":{"slug":"matrix-vesicle-lumen","display_name":"Matrix-vesicle lumen"},"participants":[{"entity":{"id":"bb7ed19e-2f65-5951-8963-40d6b3249b71","slug":"phospho1","display_name":"Phosphoethanolamine/phosphocholine phosphatase PHOSPHO1","entity_type_key":"protein"},"role":"intravesicular_enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"0da3fbd1-7438-5d0a-954d-f059bd3d22a9","slug":"matrix-vesicle","display_name":"Mineralizing matrix vesicle","entity_type_key":"organelle"},"role":"compartment","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"cd538be5-1596-5a39-97e4-d3c12137e6be","slug":"phosphoethanolamine","display_name":"Phosphoethanolamine","entity_type_key":"small_molecule"},"role":"assay_substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ee63fe8e-92f3-552f-8049-a5f1fa1e1523","slug":"phosphate-ion","display_name":"Inorganic phosphate (Pi; protonation depends on pH)","entity_type_key":"ion"},"role":"enzyme_product","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"bbc04310-3be9-5f58-8a03-d60b4fd59ad9","slug":"matrix-vesicle-lumen","display_name":"Matrix-vesicle lumen","entity_type_key":"organelle"},"role":"experimental_location","stoichiometry":null,"state_label":"","sequence_order":4,"notes":"Study location; presence here is not a separate transport or causal claim."}]},"contexts":[{"dimension":"compartment_description","value_text":"Matrix-vesicle lumen","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Localization and activity assays, including Alpl-deficient vesicles","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Localization does not establish the sole route for vesicle phosphate or calcium entry.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Calcium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Mus musculus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Mineralizing vesicles contain phosphate-generating machinery within their membrane.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[roberts2007] Functional involvement of PHOSPHO1 in matrix vesicle-mediated skeletal mineralization (2007). https://pubmed.ncbi.nlm.nih.gov/17227223/ DOI: 10.1359/jbmr.070108","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Osteoblast-derived matrix vesicles","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"f2f999a6-c2b6-55d6-bfc6-63eef8a599fc","evidence_kind":"source_excerpt","locator":"Lines 919-929","start_line":919,"end_line":929,"excerpt":"### phospho1-in-matrix-vesicles\nActive PHOSPHO1 was detected inside osteoblast-derived matrix vesicles; phosphoethanolamine hydrolase activity became accessible after vesicle sonication.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Mineralizing vesicles contain phosphate-generating machinery within their membrane.\norganism: Mus musculus\ntissue_or_cell_type: Osteoblast-derived matrix vesicles\nexperimental_model: Localization and activity assays, including Alpl-deficient vesicles\nlimitations: Localization does not establish the sole route for vesicle phosphate or calcium entry.\ncompartment_description: Matrix-vesicle lumen\n[roberts2007] Functional involvement of PHOSPHO1 in matrix vesicle-mediated skeletal mineralization (2007). https://pubmed.ncbi.nlm.nih.gov/17227223/ DOI: 10.1359/jbmr.070108","model_system":"Localization and activity assays, including Alpl-deficient vesicles","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [roberts2007] Functional involvement of PHOSPHO1 in matrix vesicle-mediated skeletal mineralization (2007). https://pubmed.ncbi.nlm.nih.gov/17227223/ DOI: 10.1359/jbmr.070108","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3c083fa0-59c6-50e9-af42-678d0e3c1006","stable_key":"import-434e1e27-eb90-583a-956b-62472726ffba","title":"Calcium: mechanism-first literature curation (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":"965c934d6b147f2b62f8d45ce6d7a87681a600bfe5c46a585b4704889afd3fc1","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}