Protein phosphatase 2A (PP2A) promotes anaphase entry after DNA replication stress in budding yeast.
Protein phosphatase 2A (PP2A) promotes anaphase entry after DNA replication stress in budding yeast.
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DOI：
10.1091/mbc.e21-04-0222
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发表时间：
2021-12-01
影响因子：
3.3
通讯作者：
Wang Y
中科院分区：
文献类型：
--
作者：
Haluska C;Jin F;Wang Y
DNA 复制应激会激活 S 期检查点，使细胞周期停滞，但人们对细胞如何从这种停滞中恢复知之甚少。细胞周期蛋白依赖性激酶 (CDK) 和蛋白磷酸酶 2A (PP2A) 是关键的细胞周期调节因子，Cdc55 是芽殖酵母中 PP2A 的调节亚基。我们发现，缺乏功能性 PP2ACdc55 的酵母细胞在 DNA 合成抑制剂羟基脲 (HU) 的存在下表现出缓慢的生长，但没有明显的活力损失。此外，PP2A 突变体在 HU 处理后表现出延迟进入后期和持续水平的后期抑制剂 Pds1。 DNA 损伤检查点 Chk1 磷酸化并稳定 Pds1。我们表明，CHK1Δ 和 Pds1 中 Chk1 磷酸化位点的突变在很大程度上恢复了 HU 处理后 PP2A 突变体的有效后期进入。此外，编码CDK抑制性激酶的SWE1的缺失或CDK中Swe1磷酸化位点（cdc28F19）的突变也抑制了HU处理后PP2A突变体的后期进入延迟。我们的遗传数据表明 Swe1/CDK 在 Pds1 上游发挥作用。令人惊讶的是，cdc55Δ 在 DNA 合成阻断期间显示出对 S 期检查点突变体活力丧失的显着抑制。总之，我们的结果揭示了 PP2A-Swe1-CDK-Chk1-Pds1 轴，可促进 DNA 复制应激的恢复。
DNA replication stress activates the S-phase checkpoint that arrests the cell cycle, but it is poorly understood how cells recover from this arrest. Cyclin-dependent kinase (CDK) and protein phosphatase 2A (PP2A) are key cell cycle regulators, and Cdc55 is a regulatory subunit of PP2A in budding yeast. We found that yeast cells lacking functional PP2ACdc55 showed slow growth in the presence of hydroxyurea (HU), a DNA synthesis inhibitor, without obvious viability loss. Moreover, PP2A mutants exhibited delayed anaphase entry and sustained levels of anaphase inhibitor Pds1 after HU treatment. A DNA damage checkpoint Chk1 phosphorylates and stabilizes Pds1. We show that chk1Δ and mutation of the Chk1 phosphorylation sites in Pds1 largely restored efficient anaphase entry in PP2A mutants after HU treatment. In addition, deletion of SWE1, which encodes the inhibitory kinase for CDK or mutation of the Swe1 phosphorylation site in CDK (cdc28F19), also suppressed the anaphase entry delay in PP2A mutants after HU treatment. Our genetic data suggest that Swe1/CDK acts upstream of Pds1. Surprisingly, cdc55Δ showed significant suppression to the viability loss of S-phase checkpoint mutants during DNA synthesis block. Together, our results uncover a PP2A-Swe1-CDK-Chk1-Pds1 axis that promotes recovery from DNA replication stress.
影响因子：
4.5
作者：
Abreu CM;Kumar R;Hamilton D;Dawdy AW;Creavin K;Eivers S;Finn K;Balsbaugh JL;O'Connor R;Kiely PA;Shabanowitz J;Hunt DF;Grenon M;Lowndes NF
通讯作者：
Lowndes NF