TACSTD2 (TROP2) notes

Deep research providers unavailable (no API keys). Notes from UniProt P09758 and cached literature.

Identity / topology

• TROP2 / tumor-associated calcium signal transducer 2, EPCAM family. Single-pass type I membrane glycoprotein:
  signal peptide 1-26, extracellular domain 27-274 (thyroglobulin type-1 domain 70-145), TM 275-297,
  short cytoplasmic tail 298-323 (with a PIP2-binding/HIKE motif and a PKC phosphorylation site).
• [UniProt P09758 "Membrane; Single-pass type I membrane protein"]; [UniProt "Belongs to the EPCAM family"].
• Localization conclusion: plasma membrane, large glycosylated ectodomain exposed at the cell surface (the
  epitope for the ADC sacituzumab govitecan), cytoplasmic tail intracellular; in polarized epithelia it is
  lateral/basolateral and at cell-cell contacts. A shed ectodomain and a cleaved intracellular domain (nuclear)
  are described for the EPCAM family.

Function

• UniProt function is weakly defined: [UniProt "May function as a growth factor receptor"] (no experimental
  evidence code). TROP2 modulates epithelial cell proliferation, migration and cell-cell adhesion; mouse Trop2
  annotations describe negative regulation of migration/motility/spreading and ureteric bud branching.
• Disease: loss-of-function causes gelatinous drop-like corneal dystrophy (GDLD), an autosomal recessive corneal
  amyloidosis PMID:10192395, reflecting a role in corneal epithelial barrier integrity.
• Clinically a major ADC target in breast/urothelial cancer (sacituzumab govitecan); general knowledge, not used
  as annotation evidence.