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Redox Regulation of EGFR Signaling in Innate Airway Epithelial Responses to Injury
Author(s) -
Heppner David,
Hristrova Milena,
Habibovic Aida,
Vliet Albert
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.863.4
Subject(s) - microbiology and biotechnology , proto oncogene tyrosine protein kinase src , epidermal growth factor receptor , transactivation , signal transduction , tyrosine kinase , purinergic receptor , chemistry , nadph oxidase , protein tyrosine phosphatase , receptor tyrosine kinase , biology , biochemistry , receptor , reactive oxygen species , transcription factor , gene
The epidermal growth factor receptor (EGFR) is expressed in airway epithelia and facilitates epithelial responses to various environmental triggers by promoting wound responses and producing inflammatory cytokines. It is known that EGFR activation is controlled by redox‐dependent mechanisms through reversible cysteine oxidation of its negative regulator, protein tyrosine phosphatase 1B (PTP1B), upstream Src‐family tyrosine kinases, or EGFR directly. However, these oxidant‐dependent mechanisms remain unclear. To these ends, we have determined that epithelial injury leads to EGFR transactivation by initial activation of purinergic receptors, via cellular release of ATP, which involves Src activation, and is mediated by the NADPH oxidase dual oxidase 1 (DUOX1). Oxidant‐dependent cysteine modifications to proteins in response to ATP stimulation were determined via biotin labeling strategies. We observed that ATP stimulation induced both sulfenylation or glutathionylation modifications within Src, EGFR, and PTP1B, and each was dependent on DUOX1. Dimedone trapping experiments furthermore indicated that sulfenylation preceded glutathionylation, indicating a sequential oxidation mechanism with initial sulfenylation followed by glutathionylation. In vitro studies with purified proteins show oxidation via H 2 O 2 enhances EGFR tyrosine kinase activity, whereas glutathionylation via GSSG did not. Similarly, H 2 O 2 enhances Src kinase activity but, at higher concentrations, is inhibitory. Our findings offer insights into the mechanisms by which DUOX1‐derived H 2 O 2 regulates EGFR‐dependent signaling as a major contributor to epithelial wound responses. Supported by NIH HL085646 and HL076122