Receptor tyrosine-protein kinase erbB-2 dimerization interface (HER2 dimerization interface)

The HER2 dimerization interface refers to the specific structural region, primarily within domain II of the extracellular region of the Receptor tyrosine-protein kinase erbB-2 (HER2/ERBB2), responsible for mediating physical interactions (dimerization) with itself (homodimerization) or with other family members such as EGFR (ERBB1), HER3 (ERBB3), or HER4 (ERBB4)[1][3][5][6]. This dimerization is required for full activation of HER2's kinase function and subsequent initiation of downstream signaling required for cell proliferation and survival. HER2 does not have its own ligand but serves as a preferred dimerization partner for other ligand-bound ERBB family receptors. The dimerization interface is highly relevant in cancer biology: in tumor cells, pathological stabilization of HER2 dimers (especially with HER3) leads to constitutive activation of proliferative and anti-apoptotic pathways. Therapeutically, the interface is directly targeted by pertuzumab, which sterically blocks the ability of HER2 to form dimers, thereby inhibiting downstream oncogenic signaling[2]. The nature and dynamics of dimerization vary depending on the exact partners and are affected by disease-associated mutations, contributing to differential drug responses and resistance mechanisms[1][2][5][6].

Other names

HER2 dimer interfaceERBB2 dimer interfaceHuman epidermal growth factor receptor 2 dimerization siteHER2/neu dimerization interface

Monoclonal antibodies: Block the dimerization interface, prevent HER2 dimerization with HER3 or EGFR (e.g., pertuzumab) Kinase inhibitors: Compete for ATP binding in the intracellular kinase domain, block downstream signaling, and can influence dimeric stability (e.g., lapatinib) Allosteric inhibition: Alter conformational state to disrupt dimer formation or activation