Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229-3900, USA.
Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229-3900, USA.
Nat Commun. 2018 May 23;9(1):2025. doi: 10.1038/s41467-018-04327-0.
Yeast Rad1-Rad10 (XPF-ERCC1 in mammals) incises UV, oxidation, and cross-linking agent-induced DNA lesions, and contributes to multiple DNA repair pathways. To determine how Rad1-Rad10 catalyzes inter-strand crosslink repair (ICLR), we examined sensitivity to ICLs from yeast deleted for SAW1 and SLX4, which encode proteins that interact physically with Rad1-Rad10 and bind stalled replication forks. Saw1, Slx1, and Slx4 are critical for replication-coupled ICLR in mus81 deficient cells. Two rad1 mutations that disrupt interactions between Rpa1 and Rad1-Rad10 selectively disable non-nucleotide excision repair (NER) function, but retain UV lesion repair. Mutations in the analogous region of XPF also compromised XPF interactions with Rpa1 and Slx4, and are proficient in NER but deficient in ICLR and direct repeat recombination. We propose that Rad1-Rad10 makes distinct contributions to ICLR depending on cell cycle phase: in G1, Rad1-Rad10 removes ICL via NER, whereas in S/G2, Rad1-Rad10 facilitates NER-independent replication-coupled ICLR.
酵母 Rad1-Rad10（哺乳动物中的 XPF-ERCC1）可切割 UV、氧化和交联剂诱导的 DNA 损伤，并参与多种 DNA 修复途径。为了确定 Rad1-Rad10 如何催化交联修复（ICLR），我们研究了酵母中缺失 Saw1 和 Slx4 的细胞对 ICL 的敏感性，这两种蛋白与 Rad1-Rad10 相互作用并结合停滞的复制叉。Saw1、Slx1 和 Slx4 对于 Mus81 缺陷细胞中复制偶联的 ICLR 至关重要。两种破坏 Rpa1 和 Rad1-Rad10 之间相互作用的 rad1 突变选择性地使非核苷酸切除修复（NER）功能失活，但保留 UV 损伤修复。XPF 中类似区域的突变也损害了 XPF 与 Rpa1 和 Slx4 的相互作用，并且在 NER 中有效，但在 ICLR 和直接重复重组中无效。我们提出 Rad1-Rad10 根据细胞周期阶段对 ICLR 做出不同的贡献：在 G1 期，Rad1-Rad10 通过 NER 去除 ICL，而在 S/G2 期，Rad1-Rad10 促进 NER 独立的复制偶联 ICLR。
