id: A0A9L0KCT9
gene_symbol: SAT1
taxon:
  id: NCBITaxon:9793
  label: Equus asinus
status: COMPLETE
description: Assessment of the single ProtNLM2 GO prediction for donkey SAT1 (A0A9L0KCT9), judged against the
  donkey GOA record (diamine N-acetyltransferase activity, broader transferase terms, spermidine binding, polyamine
  metabolic process, cytoplasm), the human ortholog P21673 and its characterization, and a donkey-human alignment
  (97% identity, catalytic Tyr140 conserved). The prediction, putrescine catabolic process, is not in donkey GOA
  and is neither established nor refuted by the available evidence, which is conflicting (UNC). Non-GO ProtNLM2 output, not scored -
  subcellular location 'Nucleus', which conflicts with the cytosolic localization of the human enzyme.
source_documents:
- projects/PROTNLM_EVALUATION/donkey40/donkey40-predictions.tsv
- genes/EQUAS/SAT1/SAT1-goa.tsv
- genes/human/SAT1/SAT1-uniprot.txt
- genes/EQUAS/SAT1/SAT1-bioinformatics/RESULTS.md
predictions:
- source_method: ProtNLM2
  source_version: UniProt API snapshot 2026-10-14
  predicted_term:
    id: GO:0009447
    label: putrescine catabolic process
  predicted_term_type: GO_BP
  review:
    assessment: UNC
    confidence_score: 1
    summary: Not in donkey GOA, which has the broader polyamine metabolic process; the donkey gene review refines
      that to polyamine, spermidine and spermine catabolic process and leaves putrescine acetylation by SAT1 as an
      open question. SAT1's established substrates are spermidine and spermine (also norspermidine and
      1,3-diaminopropane); their N1-acetylation and oxidation generate putrescine rather than consume it. Purified
      rat liver SSAT, the inducible SAT1-type enzyme, was inactive with putrescine. Against this, a mouse study
      attributes N-acetylputrescine production in the gut to Sat1, though without direct enzymology on purified
      Sat1 with putrescine, and human UniProt maps SAT1 to the UniPathway step 'N-acetylputrescine from putrescine'
      (which the human gene review keeps as a non-core role). With direct substrate-specificity data negative and
      the positive claim indirect, the evidence neither validates nor refutes a role of SAT1 in putrescine
      catabolism.
    supported_by:
    - reference_id: file:human/SAT1/SAT1-uniprot.txt
      supporting_text: norspermidine = spermidine >> spermine
    - reference_id: PMID:6615454
      supporting_text: but was inactive with putrescine, cadaverine, sym-homospermidine and N1-acetylspermidine
    - reference_id: PMID:42206375
      supporting_text: Metabolomic analysis identified the microbial conversion of BPF to N-acetylputrescine (NAP).
        Mechanistically, we found that BPF stimulated intestinal epithelial cells to secrete spermidine/spermine
        N1-acetyltransferase 1 (Sat1), which catalyzed this conversion
    - reference_id: PMID:1985966
      supporting_text: rate-limiting enzyme in the catabolism of polyamines
references:
- id: file:EQUAS/SAT1/SAT1-goa.tsv
  title: Donkey SAT1 GOA annotations
  findings: []
- id: file:human/SAT1/SAT1-uniprot.txt
  title: UniProt Swiss-Prot record for human SAT1 (P21673)
  findings: []
- id: file:EQUAS/SAT1/SAT1-bioinformatics/RESULTS.md
  title: 'SAT1: donkey-human sequence comparison'
  findings: []
- id: PMID:1985966
  title: Isolation and characterization of a cDNA clone that codes for human spermidine/spermine N1-acetyltransferase.
  findings: []
- id: PMID:6615454
  title: Studies of the specificity and kinetics of rat liver spermidine/spermine N1-acetyltransferase.
  findings: []
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: Abstract checked via PubMed; purified rat liver SSAT substrate specificity, inactive with putrescine.
- id: PMID:42206375
  title: Microplastic Exposure Aggravates Cardiomyopathy Under Hemodynamic Stress Through the Gut-Heart Axis.
  findings: []
  reference_review:
    relevance: MEDIUM
    correctness: LOW_QUALITY
    review_notes: Mouse study attributing N-acetylputrescine production to Sat1 from cell and metabolomic data; no
      kinetic assay of purified Sat1 with putrescine, so it does not settle putrescine acetylation by SAT1.