Mediator of DNA damage checkpoint 1 (MDC1) contributes to high NaCl-induced activation of the osmoprotective transcription factor TonEBP/OREBP.
Mediator of DNA damage checkpoint 1 (MDC1) contributes to high NaCl-induced activation of the osmoprotective transcription factor TonEBP/OREBP.
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DOI：
10.1371/journal.pone.0012108
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发表时间：
2010-08-11
期刊：
影响因子：
3.7
通讯作者：
Ferraris JD
中科院分区：
文献类型：
--
作者：
Kunin M;Dmitrieva NI;Gallazzini M;Shen RF;Wang G;Burg MB;Ferraris JD
高渗，如高NaCl诱导的，增加了转录因子TonEBP/OREBP的活性，其靶基因增加了细胞保护性有机渗透压物质和热休克蛋白。我们使用质谱分析与TonEBP/OREBP共免疫沉淀的蛋白质，以确定可能有助于其高NaCl诱导的激活。我们从DNA损伤检查点1（MDC 1）的介体中鉴定了20个具有高概率的独特肽。通过Western分析证实了该鉴定。我们使用小干扰RNA敲低MDC 1来表征其渗透功能。敲低MDC 1降低高NaCl诱导的TonEBP/OREBP转录和反式激活活性的增加，但对其核定位没有显著影响。我们确认了6个以前已知的磷酸化位点在MDC 1，但没有发现证据表明，高NaCl增加MDC 1的磷酸化。这表明，MDC 1作为一种DNA损伤反应蛋白，因为高渗可逆地增加DNA断裂，和其他DNA损伤反应蛋白，如ATM，也与TonEBP/OREBP和有助于其激活的高渗。MDC 1与TonEBP/OREBP相关，并有助于高NaCl诱导的该因子转录活性的增加。
Hypertonicity, such as induced by high NaCl, increases the activity of the transcription factor TonEBP/OREBP whose target genes increase osmoprotective organic osmolytes and heat shock proteins. We used mass spectrometry to analyze proteins that coimmunoprecipitate with TonEBP/OREBP in order to identify ones that might contribute to its high NaCl-induced activation. We identified 20 unique peptides from Mediator of DNA Damage Checkpoint 1 (MDC1) with high probability. The identification was confirmed by Western analysis. We used small interfering RNA knockdown of MDC1 to characterize its osmotic function. Knocking down MDC1 reduces high NaCl-induced increases in TonEBP/OREBP transcriptional and transactivating activity, but has no significant effect on its nuclear localization. We confirm six previously known phosphorylation sites in MDC1, but do not find evidence that high NaCl increases phosphorylation of MDC1. It is suggestive that MDC1 acts as a DNA damage response protein since hypertonicity reversibly increases DNA breaks, and other DNA damage response proteins, like ATM, also associate with TonEBP/OREBP and contribute to its activation by hypertonicity. MDC1 associates with TonEBP/OREBP and contributes to high NaCl-induced increase of that factor's transcriptional activity.
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DOI：
10.1152/ajprenal.90424.2008
发表时间：
2008-12-01
影响因子：
4.2
作者：
Dmitrieva, Natalia I.;Burg, Maurice B.
通讯作者：
Burg, Maurice B.
DOI：
10.1073/pnas.0504870102
发表时间：
2005-07-26
影响因子：
11.1
作者：
Dmitrieva, NI;Celeste, A;Burg, MB
通讯作者：
Burg, MB
影响因子：
64.8
作者：
Lou, ZK;Minter-Dykhouse, K;Chen, JJ
通讯作者：
Chen, JJ
DOI：
10.1073/pnas.0308463100
发表时间：
2004-02-24
影响因子：
11.1
作者：
Dmitrieva, NI;Cai, Q;Burg, MB
通讯作者：
Burg, MB
影响因子：
46.9
作者：
Kim, DH;Behlke, MA;Rossi, JJ
通讯作者：
Rossi, JJ