Department of Environment and Health, Mechanisms, Biomarkers and Models Section, Genome Stability Group, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
FAST, Core Facilities Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
Nucleic Acids Res. 2024 Nov 11;52(20):12334-12350. doi: 10.1093/nar/gkae807.
Replication-dependent DNA double-strand breaks are harmful lesions preferentially repaired by homologous recombination (HR), a process that requires processing of DNA ends to allow RAD51-mediated strand invasion. End resection and subsequent repair are two intertwined processes, but the mechanism underlying their execution is still poorly appreciated. The WRN helicase is one of the crucial factors for end resection and is instrumental in selecting the proper repair pathway. Here, we reveal that ordered phosphorylation of WRN by the CDK1, ATM and ATR kinases defines a complex regulatory layer essential for correct long-range end resection, connecting it to repair by HR. We establish that long-range end resection requires an ATM-dependent phosphorylation of WRN at Ser1058 and that phosphorylation at Ser1141, together with dephosphorylation at the CDK1 site Ser1133, is needed for the proper metabolism of RAD51 foci and RAD51-dependent repair. Collectively, our findings suggest that regulation of WRN by multiple kinases functions as a molecular switch to allow timely execution of end resection and repair at replication-dependent DNA double-strand breaks.
复制依赖性 DNA 双链断裂是有害的损伤，优先通过同源重组（HR）进行修复，这是一个需要处理 DNA 末端以允许 RAD51 介导的链入侵的过程。末端切除和随后的修复是两个交织在一起的过程，但它们执行的机制仍未被很好地理解。WRN 解旋酶是末端切除的关键因素之一，对于选择适当的修复途径至关重要。在这里，我们揭示了 CDK1、ATM 和 ATR 激酶对 WRN 的有序磷酸化定义了一个复杂的调控层，对于正确的长距离末端切除至关重要，将其与 HR 修复联系起来。我们确定长距离末端切除需要 ATM 依赖性 WRN 丝氨酸 1058 的磷酸化，并且丝氨酸 1141 的磷酸化与 CDK1 位点丝氨酸 1133 的去磷酸化一起，是 RAD51 焦点和 RAD51 依赖性修复的适当代谢所必需的。总的来说，我们的发现表明，多个激酶对 WRN 的调节作为一个分子开关，允许在复制依赖性 DNA 双链断裂处及时执行末端切除和修复。
