Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey.
Department of Molecular Biology and Genetics, College of Sciences, Koc University, Istanbul, Turkey.
Sci Rep. 2024 Feb 8;14(1):3308. doi: 10.1038/s41598-024-53472-8.
Ultraviolet (UV) component of solar radiation impairs genome stability by inducing the formation of pyrimidine-pyrimidone (6-4) photoproducts [(6-4)PPs] in plant genomes. (6-4)PPs disrupt growth and development by interfering with transcription and DNA replication. To resist UV stress, plants employ both photoreactivation and nucleotide excision repair that excises oligonucleotide containing (6-4)PPs through two subpathways: global and transcription-coupled excision repair (TCR). Here, we analyzed the genome-wide excision repair-mediated repair of (6-4)PPs in Arabidopsis thaliana and found that (6-4)PPs can be repaired by TCR; however, the main subpathway to remove (6-4)PPs from the genome is global repair. Our analysis showed that open chromatin genome regions are more rapidly repaired than heterochromatin regions, and the repair level peaks at the promoter, transcription start site and transcription end site of genes. Our study revealed that the repair of (6-4)PP in plants showed a distinct genome-wide repair profile compared to the repair of other major UV-induced DNA lesion called cyclobutane pyrimidine dimers (CPDs).
太阳辐射的紫外线（UV）成分通过在植物基因组中诱导嘧啶-嘧啶酮（6-4）光产物（[6-4]PPs）的形成来损害基因组稳定性。[6-4]PPs 通过干扰转录和 DNA 复制来破坏生长和发育。为了抵抗 UV 应激，植物既采用光复活又采用核苷酸切除修复，通过两条亚途径切除含有[6-4]PP 的寡核苷酸：全局和转录偶联切除修复（TCR）。在这里，我们分析了拟南芥中（6-4）PP 的全基因组切除修复介导的修复，并发现 TCR 可以修复[6-4]PP；然而，从基因组中去除[6-4]PP 的主要亚途径是全局修复。我们的分析表明，开放染色质基因组区域比异染色质区域修复得更快，修复水平在基因的启动子、转录起始位点和转录终止位点达到峰值。我们的研究表明，与其他主要的紫外线诱导的 DNA 损伤，如环丁烷嘧啶二聚体（CPDs）相比，植物中[6-4]PP 的修复显示出明显的全基因组修复特征。
