MUC16 (CA125) curation notes

Deep research (falcon/perplexity-lite) unavailable; notes from UniProt Q8WXI7 and cached papers.

• Topology: extracellular 1-14451, TM 14452-14472, cytoplasmic 14473-14507 (UniProt, ECO:0000305/0000255).
  Single-pass type I; ectodomain shed (CA125 serum marker).
• Apical surface: PMID:17898272; ocular H185 epitope PMID:12766047.
• Barrier: knockdown reduces rose bengal exclusion and increases S. aureus binding PMID:17898272.
  Cytoplasmic tail binds ERM proteins (PMID:17898272).
• Binds mesothelin, heterotypic adhesion PMID:14676194.
• Exosome-like vesicles (PMID:19190083, 19199708) - minor pool.
• Golgi lumen Reactome rows = O-glycosylation substrate; transit only.

Localization conclusion: apical plasma membrane, single-pass type I; giant ectodomain extracellular/
surface-exposed; shed ectodomain extracellular.