Identifying the target genes of SUPPRESSOR OF GAMMA RESPONSE 1, a master transcription factor controlling DNA damage response in Arabidopsis
Identifying the target genes of SUPPRESSOR OF GAMMA RESPONSE 1, a master transcription factor controlling DNA damage response in Arabidopsis
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DOI：
10.1111/tpj.13866
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发表时间：
2018-05-01
期刊：
影响因子：
7.2
通讯作者：
Umeda, Masaaki
中科院分区：
文献类型：
--
作者：
Ogita, Nobuo;Okushima, Yoko;Umeda, Masaaki
在哺乳动物细胞中，转录因子p53在传递DNA损伤信号以维持基因组完整性方面起着至关重要的作用。然而，在植物中，p53和检查点蛋白的同源基因缺失。相反，植物特异性转录因子抑制γ反应1 （SOG1）控制着伽马辐照诱导的大多数基因，并促进DNA修复、细胞周期阻滞和干细胞死亡。迄今为止，SOG1直接控制的基因在很大程度上仍然未知，限制了对植物DNA损伤信号传导的理解。在这里，我们进行了微阵列分析和染色质免疫沉淀（ChIP）测序，鉴定出146个拟南芥基因是SOG1的直接靶点。通过chip测序数据，我们提取了回文基序[CTT(N)(7)AAG]作为共识的sog1结合序列，该序列在DNA损伤响应中介导靶基因诱导。此外，DNA损伤引发的SOG1磷酸化是有效结合SOG1结合序列所必需的。SOG1和p53靶基因的比较表明，这两种转录因子都能调控细胞周期调控基因，如CDK抑制剂和DNA修复，而SOG1优先调控参与同源重组的基因。我们还发现防御相关基因在SOG1靶基因中富集。与这一发现一致的是，SOG1是抵抗半生物营养真菌炭疽菌（Colletotrichum higginsianum）所必需的，这表明SOG1在控制免疫应答方面具有独特的功能。
In mammalian cells, the transcription factor p53 plays a crucial role in transmitting DNA damage signals to maintain genome integrity. However, in plants, orthologous genes for p53 and checkpoint proteins are absent. Instead, the plant-specific transcription factor SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1) controls most of the genes induced by gamma irradiation and promotes DNA repair, cell cycle arrest, and stem cell death. To date, the genes directly controlled by SOG1 remain largely unknown, limiting the understanding of DNA damage signaling in plants. Here, we conducted a microarray analysis and chromatin immunoprecipitation (ChIP)-sequencing, and identified 146 Arabidopsis genes as direct targets of SOG1. By using ChIP-sequencing data, we extracted the palindromic motif [CTT(N)(7)AAG] as a consensus SOG1-binding sequence, which mediates target gene induction in response to DNA damage. Furthermore, DNA damage-triggered phosphorylation of SOG1 is required for efficient binding to the SOG1-binding sequence. Comparison between SOG1 and p53 target genes showed that both transcription factors control genes responsible for cell cycle regulation, such as CDK inhibitors, and DNA repair, whereas SOG1 preferentially targets genes involved in homologous recombination. We also found that defense-related genes were enriched in the SOG1 target genes. Consistent with this finding, SOG1 is required for resistance against the hemi-biotrophic fungus Colletotrichum higginsianum, suggesting that SOG1 has a unique function in controlling the immune response.