id: A0A8C4M285
gene_symbol: SNAP23
taxon:
  id: NCBITaxon:9793
  label: Equus asinus
status: COMPLETE
description: Assessment of the single ProtNLM2 GO prediction for the 97-residue donkey SNAP23 product A0A8C4M285,
  which retains the N-terminal SNARE motif and the palmitoylated cysteine linker of SNAP23 but lacks the C-terminal
  SNARE motif. The prediction membrane (GO:0016020) is true of the SNAP23 gene but is scored NPI for this product,
  which lacks proline 119, the DHHC17 recognition residue that full-length SNAP23 requires for membrane
  association. ProtNLM2 also emitted a subcellular location of Membrane, subject to the same caveat; no function
  text was emitted. Non-GO outputs are
  noted, not scored.
source_documents:
- projects/PROTNLM_EVALUATION/donkey40/donkey40-predictions.tsv
- projects/PROTNLM_EVALUATION/donkey40/donkey40-evidence.tsv
- genes/EQUAS/SNAP23/SNAP23-uniprot.txt
- genes/EQUAS/SNAP23/SNAP23-goa.tsv
- genes/EQUAS/SNAP23/SNAP23-bioinformatics/human-SNAP23-O00161-uniprot.txt
- genes/EQUAS/SNAP23/SNAP23-bioinformatics/RESULTS.md
predictions:
- source_method: ProtNLM2
  source_version: UniProt API snapshot 2026-10-14
  predicted_term:
    id: GO:0016020
    label: membrane
  predicted_term_type: GO_CC
  review:
    assessment: NPI
    error_type: DOMAIN_ARCHITECTURE_MISMATCH
    confidence_score: 0
    summary: Membrane is true of the SNAP23 gene, whose full-length product is a palmitoyl-anchored peripheral
      plasma-membrane protein, but this 97-residue product lacks a feature that membrane association requires.
      Donkey residues 1..89 match human SNAP23 1..89 and keep the Qb SNARE motif and all five linker cysteines;
      the product then ends in an 8-residue alternative-exon tail and lacks the region corresponding to human
      90..211. That region contains proline 119, the DHHC17 palmitoyl-transferase recognition residue. In mast
      cells the P119A mutation alone shifts full-length SNAP23 completely to the cytosol, as does loss of the
      linker cysteines, so membrane anchoring needs both the cysteines and the downstream P119 motif. Without
      P119 this product is not expected to be palmitoylated by DHHC17 or to associate with membranes, so the
      prediction is scored as a product-level architecture mismatch. Membrane association of this product has
      not been tested directly.
    supported_by:
    - reference_id: file:EQUAS/SNAP23/SNAP23-bioinformatics/human-SNAP23-O00161-uniprot.txt
      supporting_text: Lipid-anchor {ECO:0000269|PubMed:21044946}.
    - reference_id: file:EQUAS/SNAP23/SNAP23-bioinformatics/RESULTS.md
      supporting_text: all five linker cysteines (human C79, C80, C83, C85, C87) are conserved
    - reference_id: PMID:31260699
      supporting_text: either some or all cysteine residues in the linker region of SNAP-23 are required for
        anchoring of SNAP-23 to the plasma membrane in mast cells
    - reference_id: PMID:31260699
      supporting_text: The P119A mutation completely shifted localization of SNAP-23 to cytosol
references:
- id: file:EQUAS/SNAP23/SNAP23-bioinformatics/human-SNAP23-O00161-uniprot.txt
  title: UniProt record for human SNAP23 (O00161)
  findings: []
- id: file:EQUAS/SNAP23/SNAP23-bioinformatics/RESULTS.md
  title: 'SNAP23: donkey-human sequence comparison'
  findings: []
- id: PMID:31260699
  title: The cysteine-rich domain of synaptosomal-associated protein of 23 kDa (SNAP-23) regulates its membrane
    association and regulated exocytosis from mast cells.
  findings: []