Uncovering the mechanisms of DNA damage checkpoint unique to plants

DNA损伤检查点系统是维持基因组稳定性的关键。我们之前已经鉴定和分析了拟南芥SOG 1，这是一个植物特异性转录因子，控制DNA损伤反应。SOG 1是唯一已知的植物特有的DNA修复/DNA损伤反应相关转录因子。在这项研究中，我们研究了SOG 1的激活机制。我们证明了SOG 1是以ATM依赖的方式磷酸化的，并且这种磷酸化对于细胞周期停滞、转录调节和程序性细胞死亡是必不可少的。我们以前报道过，尽管SOG 1的氨基酸序列与哺乳动物肿瘤抑制因子p53的氨基酸序列完全不同，但它们在DNA损伤检查点中的功能和作用是非常相似的。我们目前的研究阐明了SOG 1功能的调节机制的新方面，这些功能与p53的性质非常相似。

DNA damage checkpoint system is crucial to maintain genome stability. We have previously identified and analyzed Arabidopsis SOG1, which is a plant-specific transcription factor, governs DNA damage response. SOG1 is the only known DNA repair-/DNA damage response-related transcription factor that is unique to plants. In this study, we investigated the mechanism of activation of SOG1. We demonstrated that SOG1 is phosphorylated in an ATM-dependent manner, and that this phosphorylation is essential for cell cycle arrest, transcriptional regulation, and programmed cell death. We have previously reported that, although the amino acid sequence of SOG1 is completely different from that of the mammalian tumor suppressor p53, their functions and roles in DNA damage checkpoint are quite similar. Our current study illuminates new aspects of the regulatory mechanisms of SOG1 functions which are mostly similar to properties of p53.