Mediator is a conserved coregulator playing a key role in RNA polymerase (Pol) II transcription. Mediator also links transcription and nucleotide excision repair (NER) via a direct contact with Rad2/ERCC5(XPG) endonuclease. In this work, we analyzed the genome-wide distribution of Rad26/ERCC6(CSB) and Rad1–Rad10/ERCC4(XPF)-ERCC1, addressing the question of a potential link of these proteins with Mediator and Pol II in yeast Saccharomyces cerevisiae. Our genomic analyses reveal that Rad1–Rad10 and Rad26 are present on the yeast genome in the absence of genotoxic stress, especially at highly transcribed regions, with Rad26 binding strongly correlating with that of Pol II. Moreover, we show that Rad1–Rad10 and Rad26 colocalize with Mediator at intergenic regions and physically interact with this complex. Using kin28 TFIIH mutant, we found that Mediator stabilization on core promoters leads to an increase in Rad1–Rad10 chromatin binding, whereas Rad26 occupancy follows mainly a decrease in Pol II transcription. Combined with multivariate analyses, our results show the relationships between Rad1–Rad10, Rad26, Mediator, and Pol II, modulated by the changes in binding dynamics of Mediator and Pol II transcription. In conclusion, we extend the Mediator link to Rad1–Rad10 and Rad26 NER proteins and reveal important differences in their dependence on Mediator and Pol II. Rad2 is the most dependent on Mediator, followed by Rad1–Rad10, whereas Rad26 is the most closely related to Pol II. Our work thus contributes to new concepts of the functional interplay between transcription and DNA repair machineries, which are relevant for human diseases including cancer and XP/CS syndromes.

中文翻译：

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Rad26 和 Rad1–Rad10 的基因组分析揭示了它们对 Mediator 和 RNA 聚合酶 II 的依赖性的差异


Mediator 是一种保守的共调节因子，在 RNA 聚合酶 (Pol) II 转录中发挥关键作用。 Mediator 还通过与 Rad2/ERCC5(XPG) 核酸内切酶直接接触，将转录和核苷酸切除修复 (NER) 连接起来。在这项工作中，我们分析了 Rad26/ERCC6(CSB) 和 Rad1–Rad10/ERCC4(XPF)-ERCC1 的全基因组分布，解决了这些蛋白质与酿酒酵母中 Mediator 和 Pol II 的潜在联系的问题。我们的基因组分析表明，在没有基因毒性应激的情况下，Rad1–Rad10 和 Rad26 存在于酵母基因组上，特别是在高度转录的区域，Rad26 的结合与 Pol II 的结合密切相关。此外，我们发现 Rad1-Rad10 和 Rad26 与 Mediator 在基因间区域共定位，并与该复合物发生物理相互作用。使用kin28 TFIIH 突变体，我们发现核心启动子上的介体稳定导致 Rad1-Rad10 染色质结合增加，而 Rad26 占据主要导致 Pol II 转录减少。结合多变量分析，我们的结果显示了 Rad1–Rad10、Rad26、Mediator 和 Pol II 之间的关系，并受到 Mediator 和 Pol II 转录结合动力学变化的调节。总之，我们将 Mediator 链接扩展到 Rad1–Rad10 和 Rad26 NER 蛋白，并揭示了它们对 Mediator 和 Pol II 依赖性的重要差异。 Rad2 最依赖 Mediator，其次是 Rad1-Rad10，而 Rad26 与 Pol II 关系最密切。因此，我们的工作有助于提出转录和 DNA 修复机制之间功能相互作用的新概念，这与包括癌症和 XP/CS 综合征在内的人类疾病相关。