特徴

• 背景：The EGFR subfamily of receptor tyrosine kinases is composed of EGFR; ErbB2; ErbB3 and ErbB4. The EGFR shares 43% - 44% aa sequence identity with the ECD of human EGFR subfamily. All these family members are type I transmembrane glycoproteins with an extracellular ligand binding domain. The extracellular ligand binding domain is containing two cysteine-rich domains separated by a spacer region and a cytoplasmic domain containing a membrane-proximal tyrosine kinase domain. Ligand binding could induce EGFR homodimerization and heterodimerization with ErbB2; resulting in cell signaling; heterodimerization tyrosine phosphorylation and kinase activation. It can bind EGF; amphiregulin; TGF-alpha; betacellulin; epiregulin; HB-EGF; epigen; and so on. Its signaling regulates multiple biological functions including cell proliferation; differentiation; motility; and apoptosis. EGFR can also be recruited to form heterodimers with the ligand-activated ErbB3 or ErbB4. EGFR is overexpressed in different tumors. Several anti-cancer drugs use EGFR as target.