Carbonylation of glycolytic proteins is a key response to drug-induced oxidative stress and apoptosis.
Recent work has highlighted the importance of protein post-translational modifications such as phosphorylation (enzymatic) and nitrosylation (nonenzymatic) in the early stages of apoptosis. In this study, we have investigated the levels of protein carbonylation, a nonenzymatic protein modification that occurs in conditions of cellular oxidative stress, during etopside-induced apoptosis of HL60 cells. Within 1 h of VP16 treatment, a number of proteins underwent carbonylation due to oxidative stress. This was inhibited by the antioxidant N-acetyl-L-cysteine. Among the proteins found to be carbonylated were glycolytic enzymes. Subsequently, we found that the rate of glycolysis was significantly reduced, probably due to a carbonylation mediated reduction in enzymatic activity of glycolytic enzymes. Our work demonstrates that protein carbonylation can be rapidly induced through cytotoxic drug treatment and may specifically inhibit the glycolytic pathway. Given the importance of glycolysis as a source of cellular ATP, this has severe implications for cell function.
England
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Tumour Biology Laboratory, Biosciences Institute, Department of Biochemistry, University College Cork, Cork, Republic of Ireland.
O'Driscoll
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Cotter
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D000111:Acetylcysteine / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D002244:Carbon / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D005047:Etoposide / Q000633:toxicity; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D006019:Glycolysis; D018922:HL-60 Cells; D006801:Humans; D006834:Hydrazines / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D011233:Precipitin Tests; D011506:Proteins / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
D016166:Free Radical Scavengers; D006834:Hydrazines; D011506:Proteins; D017382:Reactive Oxygen Species; C446799:dinitrophenylhydrazine; D005047:Etoposide; D002244:Carbon; D006861:Hydrogen Peroxide; D000111:Acetylcysteine