Epidermal growth factor receptor dimerization domain II (EGFR domain II)

Epidermal growth factor receptor dimerization domain II refers to a specific region within the extracellular portion of the human epidermal growth factor receptor (EGFR). This domain contains a "dimerization arm" that plays an essential role in mediating receptor-receptor interactions required for activation. Upon binding its ligand—such as EGF—the conformation changes so that this arm becomes exposed and can interact with another EGFR molecule's corresponding region. This interaction leads to receptor dimerization, which is necessary for activating intracellular tyrosine kinase domains and initiating downstream signaling pathways involved in cell proliferation, survival, differentiation, and migration[1][2]. Disruption or mutation within this region impairs proper signal transduction by preventing effective autophosphorylation following ligand engagement[2]. The structure consists mainly of short antiparallel beta sheets and random coils[3]. While no approved drugs currently target only Domain II directly, it remains critical for understanding how therapeutic antibodies might block or alter dimer formation—a key step in pathological signaling seen in many cancers.

Other names

EGFR dimerization armEpidermal growth factor receptor extracellular domain IIErbB1 domain II (less common, as EGFR is also known as ErbB1)

For drugs targeting the full EGFR molecule (not specifically Domain II): - Inhibition of tyrosine kinase activity (erlotinib, gefitinib) - Blockade of ligand binding and prevention of dimerization/activation (cetuximab, panitumumab)