EXO1 (human, Q9UQ84) review notes

Literature search (no deep-research provider available in this environment)

Sources checked:
- All 20 GOA-cited publications cached via just fetch-gene-pmids human EXO1
(most are abstract-only in the cache; full text for PMID:26240375, PMID:26807646,
PMID:27918544, PMID:34552057).
- Local publication cache searched for titles mentioning EXO1 / exonuclease 1 / EXOI:
found PMID:21325134 (human resection reconstitution) in addition to GOA papers;
PMID:22002605 and PMID:34520455 are yeast and were not used.
- Fetched PMID:28216226 (NBS1 phosphorylation and telomere repair choice; context for the telomere end-joining pathway-choice module proposed in ai4curation/ai-gene-review#5904, not used as evidence).
- Two speculative fetches (PMID:22325778, PMID:21496894) resolved to unrelated papers
and were not used.

Findings

• Biochemistry: 5'->3' exonuclease on ds and ssDNA plus 5'-flap endonuclease, Mg2+
  dependent PMID:10608837.
  Preferred substrates are blunt / 5'-recessed duplexes PMID:10608837.
  Catalytic residues D78, D173, D225 PMID:11842105.
  RNase H activity reported PMID:10364235.
• Mismatch repair: required for 5'- and 3'-directed excision PMID:11809771, MutSalpha
  activates and confers processivity PMID:14636568;
  reconstituted with MutSalpha, RPA (5') or also MutLalpha, PCNA, RFC (3') PMID:15225546.
• Interactions: MSH2 PMID:9788596, MLH1, MSH3 PMID:11427529, PCNA PMID:15225546, RECQ1 PMID:15886194, CtIP PMID:21052091, ZGRF1 PMID:34552057.
• HR end resection: EXO1-BLM-RPA-MRN is one of two long-range resection machineries
  PMID:21325134; CtIP/MRN
  recruit EXO1 to DSBs PMID:21052091; ATM phosphorylation of EXO1 (via MRE11 phospho) limits the
  extent of resection after IR PMID:26240375.
• Telomeres: dephospho-NBS1 recruits EXO1 to POT1-TPP1-deficient telomeres; fusions need
  EXO1 PMID:28216226.
• T-circle TAS (PMID:27918544): the paper attributes T-circles to Nbs1 and XRCC3; EXO1
  depletion had no effect on C-circles; "Exo1" used as a 3'-5' reagent is E. coli ExoI.
  No support for EXO1 in t-circle formation.
• Replication-fork resection IMP (PMID:26240375): paper studies IR-induced DSB resection
  in G2 cells, not replication forks; better captured as DSB processing.
• PMID:2414623 (protein binding, MLH1) resolves to a 1985 German paper on ulcer disease:
  wrong identifier in the UniProt-assigned GOA row.