{"id":"e23d7a96-b94e-59dc-aa08-944d3f728bd6","stable_key":"b7014def-74ec-599e-8347-167e24fec1f0:glutamate-umami-species","predicate":"determines_ligand_selectivity_in","statement":"Human/mouse receptor chimeras and point mutants mapped acidic-amino-acid selectivity to the T1R1 ligand-binding region and identified other residues that broadened mouse-type responses.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"80887478-f637-5874-943e-7fac5b5bc509","mechanism_event_label":"The species of the receptor changes what the same ligand experiment means.","subject":{"id":"2c1c5c5f-2f58-545e-9a08-b2a63ba1c8f5","slug":"tas1r1","display_name":"Human taste receptor TAS1R1","entity_type_key":"protein"},"object":{"id":"1d944380-d3e6-5e01-9649-43407fbcf8ed","slug":"human-tas1r1-tas1r3","display_name":"Human umami receptor TAS1R1/TAS1R3","entity_type_key":"protein_complex"},"evidence_count":1,"mechanism_event":{"id":"80887478-f637-5874-943e-7fac5b5bc509","stable_key":"b7014def-74ec-599e-8347-167e24fec1f0:glutamate-umami-species-event","event_type":"observed_relationship","label":"The species of the receptor changes what the same ligand experiment means.","description":"Human/mouse receptor chimeras and point mutants mapped acidic-amino-acid selectivity to the T1R1 ligand-binding region and identified other residues that broadened mouse-type responses.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"2c1c5c5f-2f58-545e-9a08-b2a63ba1c8f5","slug":"tas1r1","display_name":"Human taste receptor TAS1R1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"1d944380-d3e6-5e01-9649-43407fbcf8ed","slug":"human-tas1r1-tas1r3","display_name":"Human umami receptor TAS1R1/TAS1R3","entity_type_key":"protein_complex"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"7da684a4-2641-5bc6-93ae-8c6aa384e487","slug":"glutamate","display_name":"L-Glutamate","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"7ab6f209-2089-5008-b64e-64f8db8c7771","slug":"tas1r3","display_name":"Human taste receptor TAS1R3","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary full text","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human/mouse receptor chimeras and mutagenesis.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Sequence-dependent selectivity is not evidence that all mammalian umami receptors behave identically.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Glutamate collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"glutamate","display_name":"L-Glutamate","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The species of the receptor changes what the same ligand experiment means.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Two distinct determinants of ligand specificity in T1R1/T1R3 (the umami taste receptor). · 2013 · https://pubmed.ncbi.nlm.nih.gov/24214976/ · DOI 10.1074/jbc.M113.494443","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"e9c726db-a4fd-59c1-b7e9-1c6af4957f8e","evidence_kind":"source_excerpt","locator":"Lines 58-64","start_line":58,"end_line":64,"excerpt":"## glutamate-umami-species\nThe species of the receptor changes what the same ligand experiment means.\nHuman/mouse receptor chimeras and point mutants mapped acidic-amino-acid selectivity to the T1R1 ligand-binding region and identified other residues that broadened mouse-type responses.\nModel: Human/mouse receptor chimeras and mutagenesis.\nLimitations: Sequence-dependent selectivity is not evidence that all mammalian umami receptors behave identically.\nEvidence access: Primary full text\nTwo distinct determinants of ligand specificity in T1R1/T1R3 (the umami taste receptor). · 2013 · https://pubmed.ncbi.nlm.nih.gov/24214976/ · DOI 10.1074/jbc.M113.494443","model_system":"Human/mouse receptor chimeras and mutagenesis.","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":"c6a55239-e808-5ed7-9fa3-755a18ecb29f","stable_key":"import-b7014def-74ec-599e-8347-167e24fec1f0","title":"L-Glutamate / L-glutamic acid: carbon and nitrogen allocation, signaling 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":"3da83bd75fddeb96d17af72d7e2ae04344779957650f266521f6c8ebd59fb54f","revision_id":"55196c72-94e4-540a-a869-81d35647b04a","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}