CLDN6 notes

Deep research providers unavailable in this environment; research from UniProt P56747 and the cached
publications. Human experimental literature in GOA is limited to HCV-entry work plus interactome screens.

Topology / localization

• Tetraspan claudin (4 TM, 2 extracellular loops, cytoplasmic termini with PDZ-binding motif).
• UniProt: "SUBCELLULAR LOCATION: Cell junction, tight junction ... Cell membrane; Multi-pass membrane protein".
• Receptor-active claudin pools associating with CD81 are basolateral rather than junctional in polarized
  hepatoma cells PMID:20375010 — relevant to surface accessibility.
• Oncofetal expression: fetal epithelia, silent in adult, re-expressed in germ-cell/ovarian tumours
  (CAR-T and antibody target).

Functions

• Tight junction strand component: UniProt "Plays a major role in tight junction-specific obliteration of
  the intercellular space"; binds ZO-1/ZO-2/ZO-3.
• HCV entry receptor (host-factor role) [PMID:20375010; UniProt "Acts as a receptor for hepatitis C virus
  (HCV) entry into hepatic cells"].

Curation decisions

• All generic protein-binding rows removed: CD81/OCLN (functional content already captured by virus
  receptor activity) and seven large-scale screen hits.
• membrane -> plasma membrane + bicellular tight junction; cell adhesion (IBA) -> calcium-independent
  cell-cell adhesion.