DNA Ends Alter the Molecular Composition and Localization of Ku Multicomponent Complexes
DNA Ends Alter the Molecular Composition and Localization of Ku Multicomponent Complexes
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DOI：
10.1074/mcp.m111.013581
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发表时间：
2012-08-01
影响因子：
7
通讯作者：
Lazaro, Jean-Bernard
中科院分区：
文献类型：
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作者：
Adelmant, Guillaume;Calkins, Anne S.;Lazaro, Jean-Bernard
Ku异源二聚体在非同源末端连接和其他细胞过程中发挥重要作用，包括转录，端粒维持和凋亡。虽然Ku的功能是通过与其他蛋白质和核酸的关联来调节的，但这些大分子复合物的具体组成及其对内源性和外源性细胞刺激的动态响应还不清楚。在这里，我们使用定量蛋白质组学来定义Ku多组分复合物的组成，并证明它们在响应UV辐射时发生了显着改变。随后的生物化学分析显示，DNA末端的存在导致RNA结合蛋白被DNA和染色质相关因子取代，以产生准备用于DNA修复的大分子复合物。我们观察到Ku复合物的动态重塑与Ku和其他DNA修复蛋白从核仁的退出相一致。将剪切的DNA作为双链断裂的模拟物显微注射到活细胞中证实了这些体内发现。Molecular & Cellular Proteomics 11：10.1074/mcp.M111.013581，411-421，2012.
The Ku heterodimer plays an essential role in non-homologous end-joining and other cellular processes including transcription, telomere maintenance and apoptosis. While the function of Ku is regulated through its association with other proteins and nucleic acids, the specific composition of these macromolecular complexes and their dynamic response to endogenous and exogenous cellular stimuli are not well understood. Here we use quantitative proteomics to define the composition of Ku multicomponent complexes and demonstrate that they are dramatically altered in response to UV radiation. Subsequent biochemical assays revealed that the presence of DNA ends leads to the substitution of RNA-binding proteins with DNA and chromatin associated factors to create a macromolecular complex poised for DNA repair. We observed that dynamic remodeling of the Ku complex coincided with exit of Ku and other DNA repair proteins from the nucleolus. Microinjection of sheared DNA into live cells as a mimetic for double strand breaks confirmed these findings in vivo. Molecular & Cellular Proteomics 11: 10.1074/mcp.M111.013581, 411-421, 2012.