Mcm2-7 Is an Active Player in the DNA Replication Checkpoint Signaling Cascade via Proposed Modulation of Its DNA Gate.
Mcm2-7 Is an Active Player in the DNA Replication Checkpoint Signaling Cascade via Proposed Modulation of Its DNA Gate.
复制标题
Mcm2-7 通过对其 DNA 门的拟议调制，成为 DNA 复制检查点信号级联中的活跃参与者。
DOI：
10.1128/mcb.01357-14
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发表时间：
2015
影响因子：
5.3
通讯作者：
Schwacha,Anthony
中科院分区：
文献类型：
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作者：
Tsai,Feng-Ling;Vijayraghavan,Sriram;Prinz,Joseph;MacAlpine,HeatherK;MacAlpine,DavidM;Schwacha,Anthony
DNA复制检查点(DRC)监控并响应停滞的复制分叉，以防止基因组不稳定。核心复制因子是如何整合到这个磷酸化级联中的，目前还不完全清楚。在这里，通过对一个针对特定ATPase活性位点(Mcm2DENQ)的独特等位基因的分析，我们发现McM2-7复制解旋酶具有作为信号转导级联的一部分的新的DRC功能。该等位基因表现出正常的下游介体(Mrc1)磷酸化，暗示DRC传感器激酶激活。然而，突变体也表现出缺陷的效应蛋白激酶(Rad53)激活和经典的DRC表型。我们先前的体外分析表明，cm2DENQ突变阻止了Mcm2-7六聚体的特定构象变化。我们推测这种构象变化是其DRC角色所必需的，并提出它在变构上促进了Rad53的激活，以确保复制特异性的检查点反应。
The DNA replication checkpoint (DRC) monitors and responds to stalled replication forks to prevent genomic instability. How core replication factors integrate into this phosphorylation cascade is incompletely understood. Here, through analysis of a uniquemcmallele targeting a specific ATPase active site (mcm2DENQ), we show that the Mcm2-7 replicative helicase has a novel DRC function as part of the signal transduction cascade. This allele exhibits normal downstream mediator (Mrc1) phosphorylation, implying DRC sensor kinase activation. However, the mutant also exhibits defective effector kinase (Rad53) activation and classic DRC phenotypes. Our previousin vitroanalysis showed that themcm2DENQmutation prevents a specific conformational change in the Mcm2-7 hexamer. We infer that this conformational change is required for its DRC role and propose that it allosterically facilitates Rad53 activation to ensure a replication-specific checkpoint response.