Lee Ji-Hoon, Guo Zhi, Myler Logan R, Zheng Suting, Paull Tanya T
The Howard Hughes Medical Institute, The Department of Molecular Biosciences, and the Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America.
Department of Medicine, Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts, United States of America, and the Department of Genetics, Harvard University Medical School, Boston, Massachusetts, United States of America and the Howard Hughes Medical Institute, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
PLoS One. 2014 Jun 16;9(6):e97969. doi: 10.1371/journal.pone.0097969. eCollection 2014.
Resveratrol has been widely reported to reduce cancer progression in model systems and to selectively induce cell death in transformed cell lines. Many enzymes have been reported to respond to resveratrol in mammalian cells, including the Ataxia-Telangiectasia Mutated (ATM) protein kinase that acts in DNA damage recognition, signaling, and repair. Here we investigate the responses of ATM to resveratrol exposure in normal and transformed human cell lines and find that ATM autophosphorylation and substrate phosphorylation is stimulated by resveratrol in a manner that is promoted by reactive oxygen species (ROS). We observe direct stimulatory effects of resveratrol on purified ATM in vitro and find that the catalytic efficiency of the kinase on a model substrate is increased by resveratrol. In the purified system we also observe a requirement for oxidation, as the effect of resveratrol on ATM signaling is substantially reduced by agents that prevent disulfide bond formation in ATM. These results demonstrate that resveratrol effects on ATM are direct, and suggest a mechanism by which the oxidizing environment of transformed cells promotes ATM activity and blocks cell proliferation.
白藜芦醇已被广泛报道可在模型系统中减少癌症进展，并在转化细胞系中选择性诱导细胞死亡。据报道，许多酶在哺乳动物细胞中对白藜芦醇有反应，包括参与DNA损伤识别、信号传导和修复的共济失调毛细血管扩张突变（ATM）蛋白激酶。在此，我们研究了正常和转化的人类细胞系中ATM对白藜芦醇暴露的反应，发现白藜芦醇以活性氧（ROS）促进的方式刺激ATM自磷酸化和底物磷酸化。我们在体外观察到白藜芦醇对纯化的ATM有直接刺激作用，并发现白藜芦醇可提高该激酶对模型底物的催化效率。在纯化系统中，我们还观察到氧化的必要性，因为防止ATM中二硫键形成的试剂会大大降低白藜芦醇对ATM信号传导的影响。这些结果表明，白藜芦醇对ATM的作用是直接的，并提示了一种机制，即转化细胞的氧化环境促进ATM活性并阻断细胞增殖。
