Department of Interdisciplinary Environmental Sciences, Graduate School of Human and Environmental Sciences, Kyoto University, Kyoto, Japan.
Laboratory of DNA Damage Signaling, Department of Late Effects Studies, Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.
Genes Cells. 2023 Sep;28(9):663-673. doi: 10.1111/gtc.13056. Epub 2023 Jul 19.
The SLFN11 gene participates in cell fate decision following cancer chemotherapy and encodes the N-terminal ribonuclease (RNase) domain and the C-terminal helicase/ATPase domain. How these domains contribute to the chemotherapeutic response remains controversial. Here, we expressed SLFN11 containing mutations in two critical residues required for RNase activity in SLFN11 cells. We found that this mutant was still able to suppress DNA damage tolerance, destabilized the stalled replication forks, and perturbed recruitment of the fork protector RAD51. In contrast, we confirmed that the helicase domain was essential to accelerate fork degradation. The fork degradation by the RNase mutant was dependent on both DNA2 and MRE11 nuclease, but not on MRE11's novel interactor FXR1. Collectively, these results supported the view that the RNase domain function is dispensable for SLFN11 to mediate cell fate decision during replication stress response.
SLFN11 基因参与癌症化疗后的细胞命运决定，其编码 N 端核糖核酸酶（RNase）结构域和 C 端解旋酶/ATP 酶结构域。这些结构域如何影响化疗反应仍存在争议。在这里，我们在 SLFN11 细胞中表达了含有两个关键残基突变的 SLFN11，这两个残基对于 RNase 活性是必需的。我们发现，这种突变体仍能抑制 DNA 损伤耐受，使停滞的复制叉不稳定，并干扰叉保护蛋白 RAD51 的募集。相比之下，我们证实解旋酶结构域对于加速叉降解是必需的。RNase 突变体的叉降解依赖于 DNA2 和 MRE11 核酸酶，但不依赖于 MRE11 的新型相互作用因子 FXR1。总之，这些结果支持这样一种观点，即 RNase 结构域的功能对于 SLFN11 在复制应激反应过程中介导细胞命运决定是可有可无的。
