title: Molecular Basis for Redox Activation of Epidermal Growth Factor Receptor Kinase.
abstract: Epidermal growth factor receptor (EGFR) is a target of signal-derived H2O2, and oxidation of active-site cysteine 797 to sulfenic acid enhances kinase activity. Although a major class of covalent drugs targets C797, nothing is known about its catalytic importance or how S-sulfenylation leads to activation. Here, we report the first detailed functional analysis of C797. In contrast to prior assumptions, mutation of C797 diminishes catalytic efficiency in vitro and cells. The experimentally determined pKa and reactivity of C797 toward H2O2 correspondingly distinguish this residue from the bulk of the cysteinome. Molecular dynamics simulation of reduced versus oxidized EGFR, reinforced by experimental testing, indicates that sulfenylation of C797 allows new electrostatic interactions to be formed with the catalytic loop. Finally, we show that chronic oxidative stress yields an EGFR subpopulation that is refractory to the FDA-approved drug afatinib. Collectively, our data highlight the significance of redox biology to understanding kinase regulation and drug pharmacology.
authors.affiliation: Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA; Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Thu H
authors.initials: TH
authors.lastname: Truong
authors.affiliation: Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
authors.forename: Peter Man-Un
authors.initials: PM
authors.lastname: Ung
authors.affiliation: Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Prakash B
authors.initials: PB
authors.lastname: Palde
authors.affiliation: Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA.
authors.forename: Candice E
authors.initials: CE
authors.lastname: Paulsen
authors.affiliation: Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
authors.forename: Avner
authors.initials: A
authors.lastname: Schlessinger
authors.affiliation: Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA. Electronic address: kcarroll@scripps.edu.
authors.forename: Kate S
authors.initials: KS
authors.lastname: Carroll
mesh_terms: D000077716:Afatinib; D004789:Enzyme Activation; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D056004:Molecular Dynamics Simulation; D009154:Mutation; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D011799:Quinazolines / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000077716:Afatinib; D011494:Protein Kinases; C512478:EGFR protein, human; D066246:ErbB Receptors