PMEL (Pmel17/gp100) curation notes

Deep research (falcon/perplexity-lite) unavailable; notes from UniProt P40967 and cached papers.

• Single biosynthetic route ER -> Golgi -> endosomes -> melanosomes PMID:17991747; rapid ER/cis-Golgi
  processing PMID:15096515; transiently at cell surface (UniProt, PMID:16760433, 30988362).
• Sorted onto MVB ILVs (CD63, ApoE) [PMID:11694580; PMID:26387950].
• Processing: PC cleavage, ADAM10/17 S2 PMID:19047044, BACE2 juxtamembrane PMID:23754390, gamma-secretase.
• RPT domain forms amyloid at acidic pH, promotes eumelanin formation PMID:19666488.
• ME20-S secreted soluble form PMID:8179825; exosome pool PMID:26387950.

Localization conclusion: predominantly intracellular - ER/Golgi (biosynthetic), multivesicular
premelanosome ILVs and melanosome lumen (functional amyloid). Only transient/minor plasma membrane pool;
not a stable cell-surface protein.