HBEGF Gene: Function, Expression, and Clinical Significance

HBEGF (Heparin Binding EGF Like Growth Factor) encodes a member of the epidermal growth factor (EGF) family. The encoded preproprotein is proteolytically processed to generate a mature, soluble growth factor that binds to the EGF receptor (EGFR) and other ErbB receptors. HBEGF is synthesized as a transmembrane protein that can be cleaved by metalloproteinases to release the soluble form. It acts as a potent mitogen and chemoattractant for various cell types, including fibroblasts, smooth muscle cells, and keratinocytes. HBEGF also functions as the cellular receptor for diphtheria toxin (DTR). It plays critical roles in wound healing, cardiac development, and tumor progression.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• EGFR tyrosine kinase inhibitor resistance (KEGG hsa01521)

• ErbB signaling pathway (KEGG hsa04012)

• MAPK signaling pathway (KEGG hsa04010)

• PI3K-Akt signaling pathway (KEGG hsa04151)

HBEGF is synthesized as a 208-amino acid precursor (pro-HBEGF) with a signal peptide, a heparin-binding domain, an EGF-like domain, a transmembrane domain, and a cytoplasmic tail. The mature soluble growth factor (86-148 amino acids) is released upon proteolytic cleavage by ADAM family metalloproteinases (e.g., ADAM9, ADAM12, ADAM17). It binds with high affinity to EGFR (ErbB1) and ErbB4, inducing receptor dimerization and activation of downstream signaling cascades including MAPK and PI3K/Akt. The heparin-binding domain allows interaction with cell surface heparan sulfate proteoglycans, which modulates its bioavailability and activity. As the diphtheria toxin receptor, HBEGF mediates toxin entry into cells.