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A more recent version of this article appeared on April 1, 2007 Originally published as MBC in Press, 10.1091/mbc.E06-08-0718 on February 21, 2007
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Submitted on August 16, 2006
Revised on January 8, 2007
Accepted on January 31, 2007
Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210
Monitoring Editor: Charles Boone
Actins functional complexity makes it a likely target of oxidative stress but also places it in a prime position to coordinate the response to oxidative stress. We have previously shown that the NADPH oxidoreductase Oye2p protects the actin cytoskeleton from oxidative stress. Here we demonstrate that the physiological consequence of actin oxidation is to accelerate cell death in yeast. Loss of Oye2p leads to ROS accumulation, activation of the oxidative stress response, nuclear fragmentation and DNA degradation and premature chronological aging of yeast cells. The oye2
phenotype can be completely suppressed by removing the potential for formation of the actin C285-C374 disulfide bond, the likely substrate of the Oye2p enzyme or by treating the cells with the clinically important reductant N-acetylcysteine. Because these two cysteines are coconserved in all actin isoforms, we theorize that we have uncovered a universal mechanism whereby actin helps to coordinate the cellular response to oxidative stress by both sensing and responding to oxidative load.