id: Q10222
gene_symbol: pta1
locus_tag: SPAC1071.01c
taxon:
  id: NCBITaxon:284812
  label: Schizosaccharomyces pombe (strain 972 / ATCC 24843)
status: COMPLETE
description: Pta1 participates in CPF-mediated mRNA 3′-end formation; the predicted mRNA-processing role
  is supported but less precise than this established function.
source_documents:
- genes/SCHPO/pta1/pta1-protnlm-source.xml
- genes/SCHPO/pta1/pta1-uniprot.txt
- genes/SCHPO/pta1/pta1-ai-review.yaml
predictions:
- source_method: ProtNLM2
  source_version: pre-release post-processed-2026_02_28k.xml
  predicted_term:
    id: GO:0006397
    label: mRNA processing
  predicted_term_type: GO_BP
  review:
    assessment: LSP
    confidence_score: 2
    summary: Pta1 is a component of the experimentally characterized fission yeast CPF core. Purified-factor
      rescue of budding yeast pta1 mutant extracts establishes its conserved participation in mRNA cleavage
      and poly(A) addition. GOA already records co-transcriptional mRNA 3′-end processing, cleavage and
      polyadenylation pathway (GO:0180010). The broad mRNA-processing prediction is correct but loses
      the established mechanistic specificity and does not assign intrinsic nuclease activity.
    supported_by:
    - reference_id: PMID:33711009
      supporting_text: 'Holo-CPF consists of two component complexes (Fig 1): a 10-subunit CPF core composed
        of proteins Ysh1 (the cleavage endonuclease), Pla1 (the poly(A) polymerase), Pta1, Yth1 (a zinc
        finger protein), Pfs2 (a WD repeat protein), Iss1, Cft1 (a WD repeat protein), Cft2 (a metallo-β-lactamase/β-CASP
        protein), Ctf1, and Ssu72 (a phosphoprotein phosphatase); and a 3-subunit DPS complex comprising
        Dis2 (a phosphoprotein phosphatase), Ppn1, and Swd22 (a WD repeat protein).'
    - reference_id: PMID:10523662
      supporting_text: Extracts prepared from pta1 mutant strains are impaired in the cleavage and the
        poly(A) addition of both GAL7 and CYC1 substrates and exhibit little processing activity even
        after prolonged incubation. However, activity is efficiently rescued by the addition of purified
        CF II to the defective extracts.
  source_reference_id: file:SCHPO/pta1/pta1-protnlm-source.xml
references:
- id: PMID:33711009
  title: Structure-function analysis of fission yeast cleavage and polyadenylation factor (CPF) subunit
    Ppn1 and its interactions with Dis2 and Swd22.
- id: PMID:10523662
  title: Pta1, a component of yeast CF II, is required for both cleavage and poly(A) addition of mRNA
    precursor.
- id: file:SCHPO/pta1/pta1-protnlm-source.xml
  title: Original pre-release ProtNLM2 XML entry for pta1