Acetylation dynamics of human nuclear proteins during the ionizing radiation-induced DNA damage response
Acetylation dynamics of human nuclear proteins during the ionizing radiation-induced DNA damage response
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DOI：
10.4161/cc.24758
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发表时间：
2013-06-01
期刊：
影响因子：
4.3
通讯作者：
Andersen, Jens S.
中科院分区：
文献类型：
--
作者：
Bennetzen, Martin V.;Larsen, Dorthe Helena;Andersen, Jens S.
遗传毒性损伤，如电离辐射（IR），引起DNA损伤，引起多方面的细胞DNA损伤反应（DDR）。控制蛋白质活性、亚细胞定位、DNA结合、蛋白质-蛋白质相互作用等的DNA损伤信号传导事件严重依赖于时间依赖性翻译后修饰（ptM）。为了补充我们先前对IR诱导的核磷酸化蛋白质组的时间动力学的分析，我们现在通过使用基于质谱的蛋白质组学方法鉴定了一系列在IR诱导的DDR期间由乙酰化和主要是脱乙酰化动态调节的人类核蛋白。除了通过SILAC蛋白质组学分析对U2 oS细胞IR前和IR暴露后5和60 min的乙酰化位点进行编目外，我们还报道：（1）转录机制的关键组分，如ep 300和CReBBp，被动态乙酰化;（2）核乙酰转移酶本身不是在蛋白质丰度水平上，而是通过乙酰化（去乙酰化）进行调节;和（3）最近报道的p53共激活因子和甲基转移酶MLL 3在DDR期间在五个赖氨酸上被乙酰化。对于选定的实施例，使用蛋白质免疫沉淀和免疫印迹来评估赖氨酸乙酰化状态，从而验证质谱数据。因此，我们提出的证据表明，核蛋白，包括那些已知的调节细胞功能，通过表观遗传修饰的组蛋白，调节（去）乙酰化，在细胞暴露于遗传毒性的侮辱及时。总体而言，这些结果提供了DDR过程中蛋白质乙酰化位点谱的时间特征的资源，并提供了对有助于协调维持基因组完整性的调节ptM的高度动态性质的进一步了解。
Genotoxic insults, such as ionizing radiation (IR), cause DNA damage that evokes a multifaceted cellular DNA damage response (DDR). DNA damage signaling events that control protein activity, subcellular localization, DNA binding, protein-protein interactions, etc. rely heavily on time-dependent posttranslational modiications (ptMs). to complement our previous analysis of IR-induced temporal dynamics of nuclear phosphoproteome, we now identify a range of human nuclear proteins that are dynamically regulated by acetylation, and predominantly deacetylation, during IR-induced DDR by using mass spectrometry-based proteomic approaches. Apart from cataloging acetylation sites through SILAC proteomic analyses before IR and at 5 and 60 min after IR exposure of U2oS cells, we report that: (1) key components of the transcriptional machinery, such as ep300 and CReBBp, are dynamically acetylated; (2) that nuclear acetyltransferases themselves are regulated, not on the protein abundance level, but by (de) acetylation; and (3) that the recently reported p53 co-activator and methyltransferase MLL3 is acetylated on ive lysines during the DDR. For selected examples, protein immunoprecipitation and immunoblotting were used to assess lysine acetylation status and thereby validate the mass spectrometry data. We thus present evidence that nuclear proteins, including those known to regulate cellular functions via epigenetic modiications of histones, are regulated by (de) acetylation in a timely manner upon cell's exposure to genotoxic insults. overall, these results present a resource of temporal proiles of a spectrum of protein acetylation sites during DDR and provide further insights into the highly dynamic nature of regulatory ptMs that help orchestrate the maintenance of genome integrity.