Pharmacology and signaling properties of epidermal growth factor receptor isoforms studied by bioluminescence resonance energy transfer

We have developed a new assay for measuring epidermal growth factor receptor (EGFR) activation using the biolumines-cence resonance energy transfer (BRET) technology, which directly measures the recruitment of signaling proteins to acti-vated EGFR. Our results demonstrate that EGFR BRET assays precisely measure the pharmacology and signaling properties of EGFR expressed in human embryonic kidney 293T cells. EGFR BRET assays are highly sensitive to known EGFR ligands [pEC50 of epidermal growth factor (EGF) 10.1 0.09], con-sistent with previous pharmacological methods for measuring EGFR activation. We applied EGFR BRET assays to study the characteristics of somatic EGFR mutations that were recently identified in lung cancer. In agreement with recent reports, we detected constitutively active mutant EGFR isoforms, whic