{"id":"78044785-5ab5-5035-a68c-071003075e1d","stable_key":"649e861b-265a-5912-bc36-3a73e53ef892:l-serine-pisd-decarboxylation","predicate":"converts_phosphatidylserine_to","statement":"Human PISD converts phosphatidylserine to phosphatidylethanolamine in the inner mitochondrial membrane; patient fibroblasts with PISD variants showed reduced conversion.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"783279d4-2bdb-5a20-8c4d-737889d4dbfd","mechanism_event_label":"A serine-derived lipid feeds another lipid needed inside mitochondria.","subject":{"id":"43fe17a3-6659-5d31-9be7-959e6bb3f50f","slug":"pisd","display_name":"Human phosphatidylserine decarboxylase / PISD","entity_type_key":"protein"},"object":{"id":"be4a52f4-f31c-59b7-b0da-4178fbb069c8","slug":"phosphatidylethanolamine","display_name":"Phosphatidylethanolamine","entity_type_key":"lipid"},"evidence_count":1,"mechanism_event":{"id":"783279d4-2bdb-5a20-8c4d-737889d4dbfd","stable_key":"649e861b-265a-5912-bc36-3a73e53ef892:l-serine-pisd-decarboxylation-event","event_type":"observed_relationship","label":"A serine-derived lipid feeds another lipid needed inside mitochondria.","description":"Human PISD converts phosphatidylserine to phosphatidylethanolamine in the inner mitochondrial membrane; patient fibroblasts with PISD variants showed reduced conversion.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"43fe17a3-6659-5d31-9be7-959e6bb3f50f","slug":"pisd","display_name":"Human phosphatidylserine decarboxylase / PISD","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"be4a52f4-f31c-59b7-b0da-4178fbb069c8","slug":"phosphatidylethanolamine","display_name":"Phosphatidylethanolamine","entity_type_key":"lipid"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"c882cd0b-9d83-5b07-bd1c-fe4d45657dcb","slug":"l-serine","display_name":"L-Serine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"0e2dd859-6135-556e-938f-d177f1e8c1ad","slug":"phosphatidylserine","display_name":"Phosphatidylserine","entity_type_key":"lipid"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human family genetics and fibroblast lipid-conversion measurements.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"This pathway uses membrane-bound phosphatidylserine, not free serine as the direct PISD substrate.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-serine","display_name":"L-Serine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A serine-derived lipid feeds another lipid needed inside mitochondria.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"PISD is a mitochondrial disease gene causing skeletal dysplasia, cataracts, and white matter changes. · 2019 · https://pubmed.ncbi.nlm.nih.gov/30858161/ · DOI 10.26508/lsa.201900353","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"d67a3153-cc37-51fa-9a49-3f834935d15d","evidence_kind":"source_excerpt","locator":"Lines 422-428","start_line":422,"end_line":428,"excerpt":"## l-serine-pisd-decarboxylation\nA serine-derived lipid feeds another lipid needed inside mitochondria.\nHuman PISD converts phosphatidylserine to phosphatidylethanolamine in the inner mitochondrial membrane; patient fibroblasts with PISD variants showed reduced conversion.\nModel: Human family genetics and fibroblast lipid-conversion measurements.\nLimitations: This pathway uses membrane-bound phosphatidylserine, not free serine as the direct PISD substrate.\nEvidence access: Primary abstract\nPISD is a mitochondrial disease gene causing skeletal dysplasia, cataracts, and white matter changes. · 2019 · https://pubmed.ncbi.nlm.nih.gov/30858161/ · DOI 10.26508/lsa.201900353","model_system":"Human family genetics and fibroblast lipid-conversion measurements.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"70bcf57a-36bb-563f-9073-2d616e5f155a","stable_key":"import-649e861b-265a-5912-bc36-3a73e53ef892","title":"L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"22a750ce2b94f8607268c58322c48c4f0468f403b72a4008307538a6e5ff86d5","revision_id":"c1d6a7e1-9558-5bc6-9e3b-7080c26d3dbc","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}