Abstract

Damage to cellular macromolecules and organelles by chemical exposure evokes activation of various stress response pathways. To what extent different chemical stressors activate common and stressor-specific pathways is largely unknown. Here, we used quantitative phosphoproteomics to compare the signaling events induced by four stressors with different modes of action: the DNA damaging agent: cisplatin (CDDP), the topoisomerase II inhibitor: etoposide (ETO), the pro-oxidant: diethyl maleate (DEM) and the immunosuppressant: cyclosporine A (CsA) administered at an equitoxic dose to mouse embryonic stem cells. We observed major differences between the stressors in the number and identity of responsive phosphosites and the amplitude of phosphorylation. Kinase motif and pathway analyses indicated that the DNA damage response (DDR) activation by CDDP occurs predominantly through the replication-stress-related Atr kinase, whereas ETO triggers the DDR through Atr as well as the DNA double-strand-break-associated Atm kinase. CsA shares with ETO activation of CK2 kinase. Congruent with their known modes of action, CsA-mediated signaling is related to down-regulation of pathways that control hematopoietic differentiation and immunity, whereas oxidative stress is the most prominent initiator of DEM-modulated stress signaling. This study shows that even at equitoxic doses, different stressors induce distinctive and complex phosphorylation signaling cascades.

中文翻译：

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定量磷酸蛋白质组学揭示细胞对不同作用模式的化学应激源的反应。

 抽象的

化学暴露对细胞大分子和细胞器的损害会引起各种应激反应途径的激活。不同的化学应激源在多大程度上激活常见和应激源特异性途径尚不清楚。在这里，我们使用定量磷酸蛋白质组学来比较四种不同作用模式的应激源诱导的信号转导事件：DNA损伤剂：顺铂（CDDP），拓扑异构酶II抑制剂：依托泊苷（ETO），促氧化剂：马来酸二乙酯（DEM） ）和免疫抑制剂：以等毒性剂量对小鼠胚胎干细胞施用环孢素 A (CsA)。我们观察到应激源之间在响应磷酸位点的数量和特性以及磷酸化幅度方面的主要差异。激酶基序和通路分析表明，CDDP 激活的 DNA 损伤反应 (DDR) 主要通过复制应激相关的Atr激酶发生，而 ETO 通过Atr以及 DNA 双链断裂相关的Atm激酶触发 DDR 。 CsA 与 ETO 共同激活 CK2 激酶。与其已知的作用模式一致，CsA 介导的信号传导与控制造血分化和免疫的途径的下调有关，而氧化应激是 DEM 调节的应激信号传导最重要的引发因素。这项研究表明，即使在等毒剂量下，不同的应激源也会诱导独特且复杂的磷酸化信号级联反应。