{"id":"b2f0ab10-3051-5a1b-be73-22150bb45185","stable_key":"c3df3634-4c3a-5099-a5d9-e4f6344c1084:k48-proteasome-degradation","predicate":"is_degraded_by","statement":"The 26S proteasome degrades suitable Lys48-polyubiquitinated substrates; chain trimming permits continued substrate loading.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"51ea5d80-4e08-5667-995d-a7f44759c00f","mechanism_event_label":"A lysine-linked tag can help deliver a protein for breakdown.","subject":{"id":"cb5d0bef-6f32-51d3-925a-ff8e7f195145","slug":"k48-polyubiquitinated-substrate","display_name":"Lys48-polyubiquitinated protein substrates","entity_type_key":"protein_state"},"object":{"id":"3edc341f-1810-5d4f-a194-3bc8af77d3d5","slug":"proteasome-26s","display_name":"26S proteasome","entity_type_key":"protein_complex"},"evidence_count":1,"mechanism_event":{"id":"51ea5d80-4e08-5667-995d-a7f44759c00f","stable_key":"c3df3634-4c3a-5099-a5d9-e4f6344c1084:k48-proteasome-degradation-event","event_type":"biochemical_relationship","label":"A lysine-linked tag can help deliver a protein for breakdown.","description":"The 26S proteasome degrades suitable Lys48-polyubiquitinated substrates; chain trimming permits continued substrate loading.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"cb5d0bef-6f32-51d3-925a-ff8e7f195145","slug":"k48-polyubiquitinated-substrate","display_name":"Lys48-polyubiquitinated protein substrates","entity_type_key":"protein_state"},"role":"input","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"3edc341f-1810-5d4f-a194-3bc8af77d3d5","slug":"proteasome-26s","display_name":"26S proteasome","entity_type_key":"protein_complex"},"role":"protease_complex","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"90ad5cfc-7e86-542a-812a-a6c801b8471a","slug":"proteasomal-degradation","display_name":"Proteasomal protein degradation","entity_type_key":"cellular_process"},"role":"process","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"32ed7b35-bab7-512f-ad67-cf1884828c25","slug":"ubiquitin-k48-polyubiquitin","display_name":"Lys48-linked polyubiquitin chains","entity_type_key":"protein_state"},"role":"recognition_signal","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Biochemical proteasome/polyubiquitin assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Recognition and substrate accessibility matter; this is not a prediction that dietary lysine accelerates protein destruction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"organism","value_text":"Experimental proteasome system","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"A lysine-linked tag can help deliver a protein for breakdown.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[proteasome-trimming-2011] Ubiquitin chain trimming recycles the substrate binding sites of the 26 S proteasome and promotes degradation of lysine 48-linked polyubiquitin conjugates (2011). https://pubmed.ncbi.nlm.nih.gov/21632534/","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Not specified as a whole tissue; see experimental model.","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"23d4e1be-ef91-5591-b301-561bc31ba01e","evidence_kind":"source_excerpt","locator":"Lines 608-616","start_line":608,"end_line":616,"excerpt":"### k48-proteasome-degradation\nThe 26S proteasome degrades suitable Lys48-polyubiquitinated substrates; chain trimming permits continued substrate loading.\nPlain language: A lysine-linked tag can help deliver a protein for breakdown.\nCondition category: normal\norganism: Experimental proteasome system\ntissue_or_cell_type: Not specified as a whole tissue; see experimental model.\nexperimental_model: Biochemical proteasome/polyubiquitin assays.\nlimitations: Recognition and substrate accessibility matter; this is not a prediction that dietary lysine accelerates protein destruction.\n[proteasome-trimming-2011] Ubiquitin chain trimming recycles the substrate binding sites of the 26 S proteasome and promotes degradation of lysine 48-linked polyubiquitin conjugates (2011). https://pubmed.ncbi.nlm.nih.gov/21632534/","model_system":"Biochemical proteasome/polyubiquitin assays.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact quote from the accompanying curation document, not from publisher text. Original study references: [proteasome-trimming-2011] Ubiquitin chain trimming recycles the substrate binding sites of the 26 S proteasome and promotes degradation of lysine 48-linked polyubiquitin conjugates (2011). https://pubmed.ncbi.nlm.nih.gov/21632534/","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"7633bde7-dcc9-5086-91c6-a45eb96857f3","stable_key":"import-c3df3634-4c3a-5099-a5d9-e4f6344c1084","title":"L-Lysine: 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":"93998d47c21525409ba82f1c82ededf2893dff15fbe61c7deffc175b0e298e97","revision_id":"3897e31f-6624-59e1-a053-8a81b7361632","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}