Heparin-binding epidermal growth factor-like growth factor is a high-affinity, activating ligand for the epidermal growth factor receptor (EGFR/HER1/ErbB1) and for the related receptor tyrosine kinase, ErbB4. HB-EGF was originally identified by a combination of biochemical and bioactivity-based in vitro assays. Following biochemical purification, the protein was recognized as a member of the epidermal growth factor (EGF) family by molecular cloning. The HB-EGF gene resides on chromosome 5 (5q23) in the human genome.
HB-EGF is a mitogen, morphogen, motility, and cell survival factor. The protein is initially expressed in a membrane-anchored form (proHB-EGF), with a single membrane-spanning domain, a structural characteristic shared by other ErbB family ligands. HB-EGF was initially observed as a mitogenic activity recognizable in cell culture medium conditioned by macrophage-like cells. The protein was recognized to have a high affinity for immobilized...