Cloning of the gene encoding Trop-2, a cell-surface glycoprotein expressed by human carcinomas

Int J Cancer. 1995 Sep 4;62(5):610-8. doi: 10.1002/ijc.2910620520.


We have cloned by expression the cDNA encoding Trop-2, a cell-surface glycoprotein expressed by most human carcinomas. Formal proof of the identity of the clone is the hybridization to DNA and RNA from genomic TROP2 transfectants. TROP2 is a single-copy gene in human cells, hybridizes to a single 1.8-kb mRNA from expressing sources and encodes a 35,709 Da type-1 transmembrane protein with a single transmembrane domain. TROP2 is essentially identical to GA733-1. Thus, we have proven that GA733-1, for which a protein product had not been identified, is a functional gene. TROP2 is also homologous to TROP1/KSA/GA733-2, confirming the serological similarities between the 2 molecules. The homology between the Trop-1 and Trop-2 peptides is clustered in 2 extracytoplasmic domains and in the transmembrane/cytoplasmic region. Twelve cysteines and a potential cytoplasmic tyrosine phosphorylation site are also conserved. Trop-1 and Trop-2 are homologous to serum IGF-II-binding proteins and appear as signal transducers. Thus, they likely represent novel cell-surface receptors and may play a role in regulating the growth of carcinoma cells. On the other hand, we have found no evidence for a role of Trop-2 and Trop-1 as homophilic adhesion molecules.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antigens, Neoplasm / genetics*
  • Antigens, Surface / genetics*
  • Base Sequence
  • Carcinoma / metabolism*
  • Cell Adhesion Molecules*
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Epithelial Cell Adhesion Molecule
  • Gene Expression
  • Genes
  • Humans
  • Membrane Glycoproteins / genetics*
  • Molecular Sequence Data
  • Neoplasm Proteins / genetics*
  • RNA, Messenger / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • Antigens, Neoplasm
  • Antigens, Surface
  • Cell Adhesion Molecules
  • DNA, Complementary
  • Epithelial Cell Adhesion Molecule
  • Membrane Glycoproteins
  • Neoplasm Proteins
  • RNA, Messenger

Associated data

  • GENBANK/X77753