Ofut1 (O-fut1, neurotic; UniProt Q9V6X7) notes

Directory named O-fut1 (FlyBase synonym used by the Notch module brief); the
current FlyBase/UniProt symbol is Ofut1 (FBgn0033901), recorded as gene_symbol.
Fetched with just fetch-gene DROME Q9V6X7 --alias O-fut1.

Deep research

just deep-research-falcon DROME Q9V6X7 --alias O-fut1 --fallback perplexity-lite
was launched (2026-09-30). The wrapper hit its 600 s timeout and the
perplexity-lite fallback is not configured ("Provider 'perplexity' not
available"). See end of file for final status. Review is based on cached
publications and UniProt.

Key findings

• Enzyme: O-fucosylates Ser/Thr in EGF repeats of Notch and ligands
  PMID:12526814
• Required cell-autonomously in the signal-receiving cell, upstream of Notch activation; overexpression inhibits
  PMID:12526814
• Needed for Delta-Notch and Serrate-Notch binding; generates the Fringe substrate
  PMID:12909620
• Maternal neurogenic gene neurotic
  PMID:12917292
• Notch chaperone, independent of catalysis; ER protein
  [PMID:15692013 "OFUT1 ... also has a distinct Notch chaperone activity."; "This ability of OFUT1 to facilitate folding of Notch did not require its fucosyltransferase activity."]
• Catalytically dead R245A rescues embryonic neurogenesis; O-fucose dispensable for Fringe-independent signalling
  PMID:18194540
• But O-fucose monosaccharide has a temperature-sensitive essential function, redundant with Rumi O-glucose
  PMID:25378397
• Endocytic trafficking of Notch; stable complex with Notch ECD; can act extracellularly
  PMID:17329366

Review decisions

• Core MF: GO:0046922 peptide-O-fucosyltransferase activity (ER lumen).
• NEW MF: GO:0044183 protein folding chaperone (Notch-selective chaperone; PMID:15692013, PMID:18194540).
• Notch binding (IDA x2) accepted.
• positive regulation of endocytosis / protein localization to cell surface kept non-core (cargo-specific).
• cell fate commitment (intestinal stem cells; PMID:21965616) kept non-core.
• No IBA rows in GOA for this gene. PANTHER PTHR21420 / PTHR21420:SF10.

Pathway-variant notes

• Fly-specific(?) chaperone role making catalysis dispensable for many Notch events; in mouse Pofut1 the enzyme is required (catalytic role more prominent).

Deep research final status

Falcon output arrived after the wrapper timeout (O-fut1-deep-research-falcon.md); reviewed and cited in the review YAML.