Merck, E8780-50UG, Epiregulin from mouse

Biochem/physiol Actions
Binds and activates the tyrosine kinase ErbB family receptors (ErbB1-ErbB4). Inhibits the growth of several epithelial tumor cells and stimulates the growth of fibroblasts and other cell types. Its expression is upregulated in a number of carcinoma cell lines.
Physical form
Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 0.5 mg bovine serum albumin.
Preparation Note
Recombinant Mouse Epiregulin is produced from a DNA sequence encoding the mature mouse epiregulin protein sequence. The protein is expressed in E. coli.

Epiregulin is a member of EGF (epidermal growth factor) family. All members of the EGF family are synthesized as transmembrane precursors and converted to soluble forms by proteolytic cleavage. Epiregulin was originally purified from the mouse fibroblast-derived tumor cell line NIH3T3/T7. Mouse epiregulin cDNA encodes a transmembrane precursorof 162 amino acids with a mature soluble form consisting of residues 56-101. Epiregulin acts like other EGF family members by binding to and activating the tyrosine kinase ErbB family receptors (ErbB1-ErbB4). Epiregulin has a broad specificity, but this ligand seems to preferentially activate heterodimeric receptor complexes. Epiregulin inhibits the growth of several epithelial tumor cells and stimulates the growth of fibroblasts and other types of cells. Its expression is upregulated in a number of carcinoma cell lines. Epiregulin is also an autocrine growth factor in human epidermal keratinocytes, and involved in the early stages of pregnancy, regulating the attachment of the blastocyst to the uterine epithelium during the implantation process.
Analysis Note
The biological activity is measured by its ability to stimulate the ³H-thymidine incorporation in a mouse fibroblast cell line, Balb/3T3.