Institute of Cryobiology and Food Technology, Department of Cryobiology and Lyophilization, 53A Cherni Vrah Blvd., 1407 Sofia, Bulgaria.
Yeast. 2010 May;27(5):259-67. doi: 10.1002/yea.1749.
Here we provide evidence for a dependence between the increased production of reactive oxygen species and the activation of Ty1 retrotransposition. We have found that the strong activator of Ty1 mobility, methylmethane sulphonate, can not induce Ty1 retrotransposition in cells with compromised mitochondrial oxidative phosphorylation (rho(-); sco1Delta), which is the major source for production of reactive oxygen species (ROS) in Saccharomyces cerevisiae. The quantitative estimation of superoxide anions in living cells showed that rho(+) cells exposed to methylmethane sulphonate increase Ty1 retrotransposition and superoxide levels. The increase of superoxide anions by the superoxide generator menadione is accompanied by induction of Ty1 mobility without any treatment with a DNA-damaging agent. Higher frequencies of retrotransposition were found in rho(+) and rho(-) cells treated with exogenously added hydrogen peroxide or in cells with disrupted YAP1 gene characterized by increased intracellular levels of hydrogen peroxide. These data indicate that increased levels of ROS may have an independent and key role in the induction of Ty1 retrotransposition.
在这里，我们提供了证据表明活性氧物种的产生增加与 Ty1 逆转录转座的激活之间存在依赖性。我们发现，Ty1 迁移的强激活剂甲基甲烷磺酸盐不能诱导线粒体氧化磷酸化受损（rho(-); sco1Delta）的细胞中的 Ty1 逆转录转座，线粒体氧化磷酸化是酵母中活性氧（ROS）产生的主要来源。对活细胞中超氧阴离子的定量估计表明，暴露于甲基甲烷磺酸盐的 rho(+)细胞增加了 Ty1 逆转录转座和超氧水平。超氧化物生成剂甲萘醌增加超氧阴离子的同时，也伴随着 Ty1 迁移的诱导，而无需用 DNA 损伤剂处理。在外源性添加过氧化氢处理的 rho(+)和 rho(-)细胞或具有 YAP1 基因破坏特征的细胞（其细胞内过氧化氢水平增加）中，发现逆转录转座的频率更高。这些数据表明，ROS 水平的增加可能在 Ty1 逆转录转座的诱导中具有独立且关键的作用。
