Gökbuget Deniz, Lenshoek Kayla, Boileau Ryan M, Bayerl Jonathan, Huang Hector, Wiita Arun P, Laird Diana J, Blelloch Robert
The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, University of California, San Francisco, San Francisco, CA, USA.
Department of Urology, University of California, San Francisco, San Francisco, CA, USA.
Nat Struct Mol Biol. 2023 Oct;30(10):1561-1570. doi: 10.1038/s41594-023-01092-7. Epub 2023 Sep 11.
Coincident transcription and DNA replication causes replication stress and genome instability. Rapidly dividing mouse pluripotent stem cells are highly transcriptionally active and experience elevated replication stress, yet paradoxically maintain genome integrity. Here, we study FOXD3, a transcriptional repressor enriched in pluripotent stem cells, and show that its repression of transcription upon S phase entry is critical to minimizing replication stress and preserving genome integrity. Acutely deleting Foxd3 leads to immediate replication stress, G2/M phase arrest, genome instability and p53-dependent apoptosis. FOXD3 binds near highly transcribed genes during S phase entry, and its loss increases the expression of these genes. Transient inhibition of RNA polymerase II in S phase reduces observed replication stress and cell cycle defects. Loss of FOXD3-interacting histone deacetylases induces replication stress, while transient inhibition of histone acetylation opposes it. These results show how a transcriptional repressor can play a central role in maintaining genome integrity through the transient inhibition of transcription during S phase, enabling faithful DNA replication.
同步转录和DNA复制会导致复制应激和基因组不稳定。快速分裂的小鼠多能干细胞具有高度的转录活性，并经历增强的复制应激，但矛盾的是它们能维持基因组完整性。在这里，我们研究了FOXD3，一种在多能干细胞中富集的转录抑制因子，并表明其在进入S期时对转录的抑制对于最小化复制应激和保持基因组完整性至关重要。急性缺失Foxd3会导致立即出现复制应激、G2/M期阻滞、基因组不稳定和p53依赖性凋亡。FOXD3在进入S期时结合在高转录基因附近，其缺失会增加这些基因的表达。在S期对RNA聚合酶II进行瞬时抑制可减少观察到的复制应激和细胞周期缺陷。与FOXD3相互作用的组蛋白脱乙酰酶的缺失会诱导复制应激，而对组蛋白乙酰化进行瞬时抑制则会起到相反作用。这些结果表明，一种转录抑制因子如何通过在S期瞬时抑制转录在维持基因组完整性中发挥核心作用，从而实现忠实的DNA复制。
