CRT10 (Q08226, YOL063C) notes

2026-10-21 — Full re-review, independent of the ProtNLM2 predictions

Context: CRT10 is the PomBase one-to-one ortholog of SCHPO/crt10 (O42996) and its
experimentally characterised findings will be used as a transfer reference. No ProtNLM2
output was consulted.

Data and provenance

• just fetch-gene yeast CRT10 created uniprot, goa (6 rows) and stub.
• just deep-research-falcon yeast CRT10 --fallback perplexity-lite FAILED: Edison API
  authentication returned 403 Forbidden, and the perplexity-lite fallback also failed.
  No deep-research file exists; the review is built from the primary literature below.
• Cached and read: PMID:18704118 (full text), PMID:16600900 (full text),
  PMID:20139071 (full text), PMID:37968396 (full text), PMID:25534857 (abstract only).

Evolutionary context

• UniProt gives no PANTHER family for Q08226, so there is no PAINT/IBA node and no IBA
  rows. Q08226 has two strong PF08728 (CRT10) domains; the domain is fungal-specific.
• The reciprocal phmmer analysis done for the fission-yeast review
  (genes/SCHPO/crt10/crt10-bioinformatics/RESULTS-rereview.md) found Q08226 and O42996
  to be reciprocal sole hits through the CRT10-specific region, but similarity is weak
  (~60 residues) and O42996 is half the length. Transfer from Crt10 to O42996 should be
  limited to the pathway-level role; Rtt101/Mms1 complex membership has not been
  demonstrated for the fission-yeast protein.

What is experimentally established in S. cerevisiae

1. Complex membership. Crt10 co-purifies with Rtt101 and Mms1, not Cdc53 PMID:18704118. Binding to Rtt101 is Mms1-bridged
   PMID:18704118 and
   constitutive PMID:18704118.
   Two distinct Crt10 E3 assemblies, one with Paf1C PMID:25534857.
2. Nonfunctional 25S rRNA decay PMID:25534857.
3. RNR regulation (genetic, indirect): crt10 deletion gives HU resistance, partial mec1
   rescue, elevated RNR2/RNR3, acts in the Dun1-Crt1 pathway and is needed for normal CRT1
   transcript levels PMID:16600900. CRT10 is DNA-damage inducible, DUN1
   dependent.

Inferred, not established

• Substrate-adaptor (DCAF-like) molecular function: proposed by analogy only
  PMID:18704118.
  No substrate known. MF ND kept; GO:1990756 not proposed.
• Subcellular location: none reported.

Decisions

• MF ND: ACCEPT. Protein binding x2 (Rtt101): REMOVE per GO:0005515 policy; bridged
  interaction.
• CC ND: MODIFY to GO:0035361 Cul8-RING ubiquitin ligase complex. Comparator check via
  QuickGO: Mms22 (same receptor role), Mms1, Rtt101, Hrt1, Rtt107 all carry IDA part_of
  GO:0035361 (mostly from PMID:20139071, which does not assay Crt10); Crt10 lacks it only
  because PMID:18704118 was curated to protein binding.
• Nonfunctional rRNA decay IMP/IGI: ACCEPT (core). Crt10 is a subunit of the E3 that
  executes the ubiquitin-dependent step, so participation rather than mere necessity.
• No NEW transcription-regulation term: evidence is indirect genetics and GOA carries no
  process from PMID:16600900; recorded as a suggested question.