Epiregulin consists of 46 amino acid residues. Its secondary structure contains approximately 30 percent of β-sheet in the strand. Some of the residues form loops and turns due to the hydrogen bonding. The percentage of β-sheet in epiregulin depends on the domain and the secondary structures that they occupy. The polymeric molecules of epiregulin has the formula weight of 5280.1 g/mol with a polypeptide(L), a polymer type.
Structural motifs in most proteins have typical connections in an all β motif. Meaning that the polypeptide chains do not make a crossover connection or in so far as this type of connection has not been observed. Epiregulin is one of the proteins that occupies a typical connection in all β motif. Furthermore, as the structure of epiregulin forms a chain in an all β motif, it also forms β hairpinstructural motif. A β hairpin is when the two adjacent anti-parallel β strands connected by a β-turn.
Epiregulin is a member of the epidermal growth factor family. Epiregulin can function as a ligand of epidermal growth factor receptor (EGFR), as well as a ligand of most members of the ERBB (v-erb-b2 oncogene homolog) family of tyrosine-kinase receptors. The secondary structure at the C-terminus epiregulin is different from other epidermal growth factor family ligands because of the lack of hydrogen bonds. The structural difference at the C-terminus may provide an explanation for the reduced binding affinity of epiregulin to the ERBB receptors.
Cho MC, Choi HS, Lee S, et al. (2008). "Epiregulin expression by Ets-1 and ERK signaling pathway in Ki-ras-transformed cells". Biochem. Biophys. Res. Commun. 377 (3): 832–7. doi:10.1016/j.bbrc.2008.10.053. PMID18948081.
Lindvall C, Hou M, Komurasaki T, et al. (2003). "Molecular characterization of human telomerase reverse transcriptase-immortalized human fibroblasts by gene expression profiling: activation of the epiregulin gene". Cancer Res. 63 (8): 1743–7. PMID12702554.
Morita S, Shirakata Y, Shiraishi A, et al. (2007). "Human corneal epithelial cell proliferation by epiregulin and its cross-induction by other EGF family members". Mol. Vis. 13: 2119–28. PMID18079685.
Freimann S, Ben-Ami I, Dantes A, et al. (2004). "EGF-like factor epiregulin and amphiregulin expression is regulated by gonadotropins/cAMP in human ovarian follicular cells". Biochem. Biophys. Res. Commun. 324 (2): 829–34. doi:10.1016/j.bbrc.2004.09.129. PMID15474502.
Draper BK, Komurasaki T, Davidson MK, Nanney LB (2003). "Epiregulin is more potent than EGF or TGFalpha in promoting in vitro wound closure due to enhanced ERK/MAPK activation". J. Cell. Biochem. 89 (6): 1126–37. doi:10.1002/jcb.10584. PMID12898511. S2CID24643892.