Description
Epithelial cell adhesion molecule (EpCAM), also known as TROP1 and CD326, is a type I transmembrane glycoprotein that plays a role in a number of cellular processes including adhesion, signaling, maintaining stemness, proliferation, migration, and invasion (1,2). The human EpCAM protein is 314 amino acids (aa) in length with a theoretical molecular weight (MW) of ~35 kDa (1,3,4). The EpCAM protein includes a signal peptide, an extracellular N-terminal domain, a thyroglobulin type-1 domain, a carboxyl-terminal domain, a single-pass transmembrane domain, and an intracellular domain (1,3). The protein is highly conserved and has approximately 81% aa sequence identity between human and mouse (5). Trophoblast cell-surface antigen 2 (TROP2) also shares ~67% aa sequence similarity with EpCAM (1,5). While both EpCAM and TROP2 are cell surface markers expressed in the epithelium, their expression levels typically do not correlate (5). EpCAM is expressed in normal epithelial tissue and elevated expression is observed in many epithelial carcinomas (1-3) Patient tumor samples with increased EpCAM expression have been associated with poor prognosis (1). Given EpCAM's elevated expression in tumors, it has become a potential target for cancer therapy approaches, including monoclonal antibody treatment and anti-EpCAM trispecific antibodies (1,5).
EpCAM functions as an intracellular signaling molecule and contributes to regulation of epithelial-to-mesenchymal (EMT) transition (4,5). EpCAM is cleaved during the process of regulated intramembrane proteolysis (RIP) (4,5). Initial cleavage occurs at the membrane via a disintegrin and metalloprotease 17 (ADAM17) which releases EpCAM's extracellular domain (EpEx) (4,5). A secondary cleavage is mediated by presenilin 2 (PSEN2) which releases EpCAM's cytoplasmic trail (EpICD) (4,5). EpICD translocates to the nucleus where it associates with beta-catenin, FHL-2, and LEF-1 and induces transcription of genes related to EMT and tumor growth (4,5). EpCAM has also been shown to regulate structure and functionality of the apical junction complex of cells through direct interaction with claudin-7 and association with E-cadherin (2,5). Loss of EpCAM disrupts adherins junction and tight junction structure and function (2).
References
1. Mohtar MA, Syafruddin SE, Nasir SN, Low TY. Revisiting the Roles of Pro-Metastatic EpCAM in Cancer. Biomolecules. 2020; 10(2):255. https://doi.org/10.3390/biom10020255
2. Huang L, Yang Y, Yang F, et al. Functions of EpCAM in physiological processes and diseases (Review). Int J Mol Med. 2018; 42(4):1771-1785. https://doi.org/10.3892/ijmm.2018.3764
3. Brown TC, Sankpal NV, Gillanders WE. Functional Implications of the Dynamic Regulation of EpCAM during Epithelial-to-Mesenchymal Transition. Biomolecules. 2021; 11(7):956. https://doi.org/10.3390/biom11070956
4. Uniprot (P16422)
5. Schnell U, Cirulli V, Giepmans BN. EpCAM: structure and function in health and disease. Biochim Biophys Acta. 2013; 1828(8):1989-2001. https://doi.org/10.1016/j.bbamem.2013.04.018
Bioinformatics
Entrez |
Mouse Rat Human |
Uniprot |
Human Human Human Human |
Product By Gene ID |
4072 |
Alternate Names |
- 17-1A
- 323/A3
- ACSTD1
- antigen identified by monoclonal AUA1
- CD326 antigen
- Cell surface glycoprotein Trop-1
- chromosome 4, surface marker (35kD glycoprotein)
- DIAR5
- EGP
- EGP-2
- EGP314
- EGP40
- EpCAM
- epithelial cell adhesion molecule
- Epithelial cell surface antigen
- Epithelial glycoprotein 314
- Epithelial glycoprotein
- ESA
- GA733-2EGP34
- hEGP314
- HNPCC8
- KS 1/4 antigen
- KS1/4
- KSAHEA125
- M1S2
- M4S1Ly74
- Major gastrointestinal tumor-associated protein GA733-2
- MIC18MH99
- MOC31
- TACST-1
- TACSTD1
- TROP1CD326
- Tumor-associated calcium signal transducer 1CO-17A
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