DNA polymerase delta interacting protein 3 facilitates the activation and maintenance of DNA damage checkpoint in response to replication stress.
DNA polymerase delta interacting protein 3 facilitates the activation and maintenance of DNA damage checkpoint in response to replication stress.
复制标题
DOI：
10.1002/ame2.12274
复制
发表时间：
2022-10
影响因子：
3.7
通讯作者：
Zhang, Dong
中科院分区：
文献类型：
--
作者：
Zhang, Sufang;Lee, Ernest Y C;Lee, Marietta Y W T;Zhang, Dong
复制应激反应对于维持稳定的基因组至关重要。 POLDIP3（DNA 聚合酶 δ 相互作用蛋白 3）在大约 20 年前最初被鉴定为 DNA 聚合酶 δ (Pol δ) 相互作用蛋白之一。通过各种体外生化测定，我们之前确定 POLDIP3 是 Pol δ 酶活性的关键调节因子。然而，POLDIP3 在 DNA 复制和 DNA 损伤反应中的体内功能尚不清楚。我们首先使用 CRISPR/Cas9 技术生成 POLDIP3 敲除 (KO) 细胞。然后，我们使用各种生化和细胞生物学测定研究了其体内生物学功能。我们发现，尽管 POLDIP3-KO 细胞在非应激条件下整体 DNA 合成没有表现出明显的缺陷，但它们对多种复制叉阻断剂敏感。有趣的是，我们发现 POLDIP3 在响应外源和内源复制应激的 DNA 损伤检查点的激活和维持中发挥着至关重要的作用。我们的结果表明，当 DNA 复制叉被阻断时，POLDIP3 可以被招募到停滞的复制叉，并发挥桥梁早期 DNA 损伤检查点响应和后期复制叉修复/重启的作用。 DNA复制应激是基因组不稳定和肿瘤发生的主要原因。在本文中，我们展示了先前鉴定的 DNA 聚合酶 δ 相互作用蛋白 POLDIP3，其功能是桥接早期 DNA 复制应激反应事件（DNA 损伤检查点激活）和晚期 DNA 复制应激反应事件（DNA 聚合酶 δ 或 Pol δ4，依赖性叉修复/重启）。
Replication stress response is crucial for the maintenance of a stable genome. POLDIP3 (DNA polymerase delta interacting protein 3) was initially identified as one of the DNA polymerase δ (Pol δ) interacting proteins almost 20 years ago. Using a variety of in vitro biochemical assays, we previously established that POLDIP3 is a key regulator of the enzymatic activity of Pol δ. However, the in vivo function of POLDIP3 in DNA replication and DNA damage response has been elusive. We first generated POLDIP3 knockout (KO) cells using the CRISPR/Cas9 technology. We then investigated its biological functions in vivo using a variety of biochemical and cell biology assays. We showed that although the POLDIP3‐KO cells manifest no pronounced defect in global DNA synthesis under nonstress conditions, they are sensitive to a variety of replication fork blockers. Intriguingly, we found that POLDIP3 plays a crucial role in the activation and maintenance of the DNA damage checkpoint in response to exogenous as well as endogenous replication stress. Our results indicate that when the DNA replication fork is blocked, POLDIP3 can be recruited to the stalled replication fork and functions to bridge the early DNA damage checkpoint response and the later replication fork repair/restart. DNA replication stress is a major cause of genome instability and tumorigenesis. In this article, we show that a previously identified DNA polymerase δ interacting protein, POLDIP3, functions to bridge the early DNA replication stress response event (DNA damage checkpoint activation) and the late DNA replication stress response events (DNA polymerase δ, or Pol δ4, dependent fork repair/restart).