TYRP1 notes

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Activity

• Crystal structure: binuclear zinc site, not copper PMID:28661582; purified lumenal domain lacks DHICA, tyrosine hydroxylase and L-DOPA oxidase activity, but activity
  appears after copper substitution PMID:28661582. Hence tyrosinase activity rows REMOVEd; DHICA/catechol oxidase kept as non-core (disputed).
• The IDA "tyrosinase activity" row (PMID:21291857) comes from lysate tyrosinase assays in GIPC/APPL knockdown
  melanocytes, which report TYR protein levels, not a TYRP1 activity.
• Loss of function causes OCA3 PMID:21996312.

Trafficking and localization (surface benchmark)

• Melanosome membrane, single-pass type I, lumenal catalytic-like domain.
• Sorting: C-terminal Ser-Val-Val PDZ motif binds GIPC PMID:11441007; AP-1/KIF13A endosomal route PMID:19841138.
• Minor cell-surface pool in melanoma cells: detected by flow cytometry with anti-TYRP1 antibodies
  PMID:18334748 and used for CAR-T
  targeting PMID:39308793. Added as a NEW GO:0009986 cell surface annotation (non-core).
• Conclusion: primarily melanosome membrane (lumenal domain inside the organelle); a minor plasma-membrane pool
  presents the same domain extracellularly in melanoma.