Human HER3 protein (extracellular domain), biotinylated, recombinant

Description :
HER3 is a member of the epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases (RTK). Four members of the EGFR family have been identified: EGFR (ERBB1, HER1), HER2 (ERBB2), HER3 (ERBB3) and HER4 (ERBB4). They typically contain an extracellular ligand binding domain (ECD), a transmembrane domain (TM), and an intracellular kinase domain that can interact with a multitude of signaling molecules and exhibit both ligand-dependent and ligand-independent activity. EGFR signaling is initiated by ligand binding to the extracellular ligand binding domain. This initiates receptor homo-/hetero-dimerization and autophosphorylation by the intracellular kinase domain, resulting in receptor activation. Following activation, phosphorylation of cytoplasmic substrates occurs and a signaling cascade is initiated that drives many cellular responses, including changes in gene expression, cytoskeletal rearrangement, anti-apoptosis and increased cell proliferation. HER3 binds neuregulins NRG1 and NRG2, but lacks an active kinase domain. It therefore can bind this ligand but not convey the signal into the cell through protein phosphorylation. However, heterodimerization with other EGF receptor family members, which have kinase activity, leads to the activation of pathways. Amplification or overexpression of this gene has been reported in several cancers, including lung, prostate, bladder, and breast tumors. HER3 is also genetically linked to type 1 diabetes and lethal congenital contracture syndrome-2 (LCCS2).