Regulation of apoptosis by Bcl-2 cysteine oxidation in human lung epithelial cells.
Luanpitpong-S; Chanvorachote-P; Stehlik-C; Tse-W; Callery-PS; Wang-L; Rojanasakul-Y
Mol Biol Cell 2013 Mar; 24(6):858-869
Hydrogen peroxide is a key mediator of oxidative stress known to be important in various cellular processes, including apoptosis. B-cell lymphoma-2 (Bcl-2) is an oxidative stress-responsive protein and a key regulator of apoptosis; however, the underlying mechanisms of oxidative regulation of Bcl-2 are not well understood. The present study investigates the direct effect of H2O2 on Bcl-2 cysteine oxidation as a potential mechanism of apoptosis regulation. Exposure of human lung epithelial cells to H2O2 induces apoptosis concomitant with cysteine oxidation and down-regulation of Bcl-2. Inhibition of Bcl-2 oxidation by antioxidants or by site-directed mutagenesis of Bcl-2 at Cys-158 and Cys-229 abrogates the effects of H2O2 on Bcl-2 and apoptosis. Immunoprecipitation and confocal microscopic studies show that Bcl-2 interacts with mitogen-activated protein kinase (extracellular signal-regulated kinase 1/2 [ERK1/2]) to suppress apoptosis and that this interaction is modulated by cysteine oxidation of Bcl-2. The H2O2-induced Bcl-2 cysteine oxidation interferes with Bcl-2 and ERK1/2 interaction. Mutation of the cysteine residues inhibits the disruption of Bcl-2-ERK complex, as well as the induction of apoptosis by H2O2. Taken together, these results demonstrate the critical role of Bcl-2 cysteine oxidation in the regulation of apoptosis through ERK signaling. This new finding reveals crucial redox regulatory mechanisms that control the antiapoptotic function of Bcl-2.
Cell-alteration; Cell-damage; Proteins; Oxidative-processes; Oxides; Hydroxides; Cellular-function; Antioxidants; Mutagenesis; Microscopic-analysis; Oxidation-reduction-reactions; Humans; Lung-cells; Cytology; Metabolism; Drug-interaction; Spectrographic-analysis; Pharmacodynamics
Yon Rojanasakul, Department of Basic Pharmaceutical Sciences and Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV 26506
7722-84-1; 5722-80-5; 23214-92-8
Molecular Biology of the Cell