id: Q95182
gene_symbol: Equc1
product_type: PROTEIN
status: DRAFT
taxon:
  id: NCBITaxon:9796
  label: Equus caballus
description: >-
  Equ c 1, the major horse allergen: a secreted lipocalin (calycin superfamily,
  lipocalin family) that binds small hydrophobic odorant ligands in its beta-barrel
  calyx. Produced in salivary, sublingual and liver tissue and shed in dander, it is
  the dominant horse allergen and a member of the cross-reactive mammalian lipocalin
  group (with cat Fel d 4, dog Can f 6 and bovine Bos d 2).
existing_annotations:
- term:
    id: GO:0005576
    label: extracellular region
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  review:
    summary: Equ c 1 is a secreted lipocalin; extracellular localization is well supported.
    action: ACCEPT
    reason: Secretory lipocalin acting in the extracellular space.
    supported_by:
    - reference_id: file:HORSE/Equc1/Equc1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Secreted'
- term:
    id: GO:0005549
    label: odorant binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: enables
  review:
    summary: Equ c 1 binds small hydrophobic odorant ligands in its lipocalin calyx.
    action: ACCEPT
    reason: Phylogenetic inference matching the odorant-binding lipocalin family.
    supported_by:
    - reference_id: file:HORSE/Equc1/Equc1-uniprot.txt
      supporting_text: Belongs to the calycin superfamily. Lipocalin family.
- term:
    id: GO:0005576
    label: extracellular region
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: Automated subcellular-location annotation consistent with secretion.
    action: ACCEPT
    reason: Consistent with the secreted nature of the lipocalin.
    supported_by:
    - reference_id: file:HORSE/Equc1/Equc1-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Secreted'
- term:
    id: GO:0036094
    label: small molecule binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  review:
    summary: Generic parent of the more specific odorant binding already annotated.
    action: MARK_AS_OVER_ANNOTATED
    reason: Uninformative broad parent; the specific odorant-binding activity is already captured.
core_functions:
- description: Secreted odorant-binding lipocalin (major horse allergen, cross-reactive mammalian lipocalin group).
  molecular_function:
    id: GO:0005549
    label: odorant binding
  supported_by:
  - reference_id: file:HORSE/Equc1/Equc1-uniprot.txt
    supporting_text: Belongs to the calycin superfamily. Lipocalin family.
  locations:
  - id: GO:0005576
    label: extracellular region
proposed_new_terms: []
suggested_questions:
- question: What endogenous odorant/lipid does Equ c 1 carry, and does ligand identity drive its cross-reactivity with Fel d 4 / Can f 6?
  experts: []
suggested_experiments:
- hypothesis: Equ c 1 shares ligand-binding specificity with the cross-reactive lipocalins Fel d 4 and Can f 6.
  description: Compare ligand binding of recombinant Equ c 1, Fel d 4 and Can f 6 by fluorescent-probe displacement and map shared IgE epitopes by cross-inhibition.
  experiment_type: biophysical / cross-reactivity assay
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
  findings: []
- id: file:HORSE/Equc1/Equc1-uniprot.txt
  title: UniProt entry Q95182 (Major allergen Equ c 1), Equus caballus
  findings:
  - statement: Equ c 1 is a secreted odorant-binding lipocalin (calycin superfamily) major horse allergen.
    supporting_text: Belongs to the calycin superfamily. Lipocalin family.
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Curated UniProt record; supports secreted odorant-binding lipocalin classification.