CRL2(Lrr1) promotes unloading of the vertebrate replisome from chromatin during replication termination.
CRL2(Lrr1) promotes unloading of the vertebrate replisome from chromatin during replication termination.
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DOI：
10.1101/gad.291799.116
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发表时间：
2017-02-01
影响因子：
10.5
通讯作者：
Walter JC
中科院分区：
文献类型：
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作者：
Dewar JM;Low E;Mann M;Räschle M;Walter JC
在这里，杜瓦等人。使用非洲爪蟾卵提取物中的蛋白质组筛选来鉴定当 CMG 从染色质卸载（真核复制终止过程中的关键事件）被阻断时，染色质上富集的因子。他们的结果表明，CRL2Lrr1 是脊椎动物 DNA 复制终止期间复制体分解的主要调节因子。真核复制终止过程中的一个关键事件是从染色质中去除 CMG 解旋酶。 CMG 卸载涉及其 Mcm7 亚基的泛素化和 p97 ATP 酶的作用。通过对爪蟾卵提取物进行蛋白质组筛选，我们确定了当 CMG 卸载被阻断时染色质上富集的因子。该方法鉴定了 E3 泛素连接酶 CRL2Lrr1、特定的 p97 复合物、其他潜在的终止调节因子以及许多复制体组件。我们发现，Mcm7 泛素化和 CRL2Lrr1 与染色质的结合是暂时相关的，并且仅在复制终止期间发生。在缺乏 CRL2Lrr1 的情况下，Mcm7 不会泛素化，CMG 卸载受到抑制，并且包含 DNA Pol ε 的脊椎动物复制体的大亚复合体保留在 DNA 上。我们的数据表明 CRL2Lrr1 是脊椎动物 DNA 复制终止期间复制体分解的主要调节因子。
Here, Dewar et al. use a proteomic screen in Xenopus egg extracts to identify factors that are enriched on chromatin when CMG unloading from chromatin, which is a key event during eukaryotic replication termination, is blocked. Their results show that CRL2Lrr1 is a master regulator of replisome disassembly during vertebrate DNA replication termination. A key event during eukaryotic replication termination is the removal of the CMG helicase from chromatin. CMG unloading involves ubiquitylation of its Mcm7 subunit and the action of the p97 ATPase. Using a proteomic screen in Xenopus egg extracts, we identified factors that are enriched on chromatin when CMG unloading is blocked. This approach identified the E3 ubiquitin ligase CRL2Lrr1, a specific p97 complex, other potential regulators of termination, and many replisome components. We show that Mcm7 ubiquitylation and CRL2Lrr1 binding to chromatin are temporally linked and occur only during replication termination. In the absence of CRL2Lrr1, Mcm7 is not ubiquitylated, CMG unloading is inhibited, and a large subcomplex of the vertebrate replisome that includes DNA Pol ε is retained on DNA. Our data identify CRL2Lrr1 as a master regulator of replisome disassembly during vertebrate DNA replication termination.