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的关键。我们之前已经鉴定并分析了拟南芥SOG1，这是一种控制DNA损伤反应的植物特异性转录因子。SOG1是唯一已知的植物特有的DNA修复/DNA损伤应答相关转录因子。在本研究中，我们研究了SOG1的激活机制。我们证明了SOG1以atm依赖的方式磷酸化，并且这种磷酸化对于细胞周期阻滞、转录调节和程序性细胞死亡是必不可少的。我们之前报道过，虽然SOG1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非常相似。我们目前的研究阐明了SOG1功能调控机制的新方面，这些功能与p53的特性非常相似。

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.