Description
Heparin-binding EGF-like growth factor (HB-EGF) is a 12-16 kDa member of the epidermal growth factor (EGF)family. It possesses an EGF-like domain, and a heparin-binding motif. Mature HB-EGF is a soluble peptide thatarises from proteolytic processing of the transmembrane form. Human HB -EGF shows 76% and 73% aasequence identity with rat and mouse HB-EGF, respectively. It is required for normal cardiac valve formationand normal heart function, promotes smooth muscle cell proliferation. It may be involved in macrophage-mediated cellular proliferation; it is mitogenic for fibroblasts, but not endothelial cells. HB-EGF classified as agroup 2 ErbB ligand based on its ability to activate both the EGF/ErbB1 and ErbB4 receptors. Activityassociated with ErbB4 binding appears to be limited to non -mitogenic actions, while EGFR binding inducesboth mitogenic and non-mitogenic activity.