Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.
Department of Molecular Pharmaco-Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Life Sci Alliance. 2022 Jul 29;5(12):e202201584. doi: 10.26508/lsa.202201584.
DNA damage tolerance pathways are regulated by proliferating cell nuclear antigen (PCNA) modifications at lysine 164. Translesion DNA synthesis by DNA polymerase η (Polη) is well studied, but less is known about Polη-independent mechanisms. Illudin S and its derivatives induce alkyl DNA adducts, which are repaired by transcription-coupled nucleotide excision repair (TC-NER). We demonstrate that in addition to TC-NER, PCNA modification at K164 plays an essential role in cellular resistance to these compounds by overcoming replication blockages, with no requirement for Polη. Polκ and RING finger and WD repeat domain 3 (RFWD3) contribute to tolerance, and are both dependent on PCNA modifications. Although RFWD3 is a FANC protein, we demonstrate that it plays a role in DNA damage tolerance independent of the FANC pathway. Finally, we demonstrate that RFWD3-mediated cellular survival after UV irradiation is dependent on PCNA modifications but is independent of Polη. Thus, RFWD3 contributes to PCNA modification-dependent DNA damage tolerance in addition to translesion DNA polymerases.
DNA 损伤容忍途径受赖氨酸 164 上增殖细胞核抗原 (PCNA) 修饰的调节。DNA 聚合酶 η (Polη) 的跨损伤 DNA 合成研究得比较透彻,但对 Polη 不依赖的机制知之甚少。伊鲁毒素 S 及其衍生物诱导烷基 DNA 加合物,这些加合物通过转录偶联核苷酸切除修复 (TC-NER) 进行修复。我们证明,除了 TC-NER 之外,PCNA 在 K164 的修饰在克服复制阻断方面对细胞对这些化合物的抗性起着至关重要的作用,而不需要 Polη。Polκ 和环指和 WD 重复域 3 (RFWD3) 有助于耐受,两者都依赖于 PCNA 的修饰。尽管 RFWD3 是 FANC 蛋白,但我们证明它在 DNA 损伤容忍中发挥作用,而不依赖于 FANC 途径。最后,我们证明 RFWD3 介导的 UV 照射后细胞存活依赖于 PCNA 修饰,但不依赖于 Polη。因此,RFWD3 除了跨损伤 DNA 聚合酶外,还有助于 PCNA 修饰依赖性 DNA 损伤容忍。