Copyright © 2005 Cascade BioScience, Inc. All rights reserved.
The EGFR, epidermal growth factor receptor, belongs to a family of receptor tyrosine kinases in mammals which is composed of four members: EGFR (ErB1), ErB2, ErB3, and ErB4 (1). EGFR is an 1186 amino acid residue transmembrane glycoprotein (2). It consists of an extracellular ligand binding domain, a single ?-helical transmembrane pass, an intracellular tyrosine kinase domain, and a COOHterminal region that contains autophosphorylation sites (2). The binding of specific polypeptide ligands, including EGF, transforming growth factor-?, betacellulin, heparin-binding EGF, epiregulin, or amphiregulin, results in phosphorylation of multiple tyrosine residues in the COOH-terminal tail, triggering the cellular signaling pathway that regulates fundamental cellular processes such as proliferation, migration, differentiation and survival. EGFR is over expressed in many types of tumor cells, such as breast, brain, bladder, lung, gastric, head & neck, cervix, ovary, endometrium, etc (3).
1. Ullrich A et al (1984) Nature 309, 418-425.
2. Wells A (1999) Int J Biochem Cell Biol 31, 637-643.
3. Ullrich A and Schlessinger J (1990) Cell 61, 203-212.
