Recombinant Human EGF

Epidermal growth factor (EGF) is a small, potent growth factor capable of inducing cell proliferation, differentiation, and survival. EGF is the founding member of the EGF family that also includes TGF-alpha, amphiregulin (AR), betacellulin (BTC), epiregulin (EPR), heparin-binding EGF-like growth factor (HB-EGF), epigen, and the neuregulins (NRG)-1 through -6 ^[1]. Members of The EGF family are characterized by a shared structural motif, the EGF-like domain, which contains three intramolecular disulfide bonds that are formed by six similarly spaced, conserved cysteine residues ^[2]. These disulfide bonds are essential for proper protein conformation and receptor binding. All EGF family members are synthesized as type I transmembrane precursor proteins that may contain several EGF domains in the extracellular region. The mature proteins are released from the cell surface by regulated proteolysis ^[1]. The full length EGF protein is 1207 amino acids (aa) (EGF precursor) containing nine EGF domains and nine LDLR class B repeats. However, the mature protein is much smaller, only 53 aa, and is generated by proteolytic cleavage of the EGF domain proximal to the transmembrane region ^[3]. EGF is well conserved across mammals with mature human EGF 70% identical to mature mouse and rat EGF. Physiologically, EGF is found in various body fluids, including blood, milk, urine, saliva, seminal fluid, pancreatic juice, cerebrospinal fluid, and amniotic fluid ^[4]. EGF is a high affinity ligand of the EGF receptor (ErbB). Four ErbB (HER) family receptor tyrosine kinases including EGFR/ErbB1, ErbB2, ErbB3 and ErbB4, mediate responses to EGF family members ^[5]. EGF binding induces dimerization of the EGF receptor resulting in activation of the protein tyrosine kinase signaling pathway. These receptors undergo a complex pattern of ligand-induced homo-or hetero-dimerization to transduce EGF family signals ^{[6, 7]}.

Reference

[1]. Harris, R.C. et al. (2003) Exp. Cell Res. 284:2.

[2]. Carpenter, G. and Cohen, S. (1990) J. Biol. Chem. 265:7709.

[3]. Bell, G.I. et al. (1986) Nucl. Acids Res. 14:8427.

[4]. Carpenter, G. and Zendegui, J.G. (1986) Exp. Cell Res. 164:1.

[5]. Jorissen, R.N. et al. (2003) Exp. Cell Res. 284:31.

[6]. Gamett, D.C. et al. (1997) J. Biol. Chem. 272:12052.

[7]. Qian, X. et al. (1994) Proc. Natl. Acad. Sci. 91:1500.