id: O18874
gene_symbol: Canf2
product_type: PROTEIN
status: DRAFT
taxon:
  id: NCBITaxon:9615
  label: Canis lupus familiaris
description: >-
  Can f 2, a minor dog allergen: a secreted lipocalin (calycin superfamily,
  lipocalin family) related to mouse major urinary protein / odorant-binding
  lipocalins. It binds small hydrophobic odorant ligands in its beta-barrel calyx
  and is produced in salivary/skin secretions and shed on hair. It is recognized by
  IgE in a subset of dog-allergic patients.
existing_annotations:
- term:
    id: GO:0005576
    label: extracellular region
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  review:
    summary: Can f 2 is a secreted lipocalin; extracellular localization is well supported.
    action: ACCEPT
    reason: Secretory lipocalin acting in the extracellular space.
    supported_by:
    - reference_id: file:CANLF/Canf2/Canf2-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: >-
      Can f 2 binds small hydrophobic odorant ligands in its lipocalin calyx,
      consistent with its odorant-binding-lipocalin relatives.
    action: ACCEPT
    reason: Phylogenetic inference matching the odorant-binding lipocalin family.
    supported_by:
    - reference_id: file:CANLF/Canf2/Canf2-uniprot.txt
      supporting_text: Belongs to the calycin superfamily. Lipocalin family.
- term:
    id: GO:0005549
    label: odorant binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000118
  qualifier: enables
  review:
    summary: TreeGrafter (IEA) duplicate of the odorant-binding inference.
    action: ACCEPT
    reason: Electronic inference matching the lipocalin odorant-binding function.
    supported_by:
    - reference_id: file:CANLF/Canf2/Canf2-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:CANLF/Canf2/Canf2-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 that binds small hydrophobic odorant ligands
    in its beta-barrel calyx.
  molecular_function:
    id: GO:0005549
    label: odorant binding
  supported_by:
  - reference_id: file:CANLF/Canf2/Canf2-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 specific odorant/pheromone ligand does Can f 2 carry, and in which secretion is it functionally relevant?
  experts: []
suggested_experiments:
- hypothesis: Can f 2 binds specific volatile odorant ligands characteristic of its lipocalin subfamily.
  description: >-
    Characterize ligand binding of recombinant Can f 2 by fluorescent-probe
    displacement against a panel of odorants/lipids and identify native co-purifying
    ligands by GC-MS.
  experiment_type: biophysical binding 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: GO_REF:0000118
  title: TreeGrafter-generated GO annotations
  findings: []
- id: file:CANLF/Canf2/Canf2-uniprot.txt
  title: UniProt entry O18874 (Minor allergen Can f 2), Canis lupus familiaris
  findings:
  - statement: Can f 2 is a secreted odorant-binding lipocalin (calycin superfamily) minor dog 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.