Systems-wide analysis of ubiquitylation dynamics reveals a key role for PAF15 ubiquitylation in DNA-damage bypass
Systems-wide analysis of ubiquitylation dynamics reveals a key role for PAF15 ubiquitylation in DNA-damage bypass
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DOI：
10.1038/ncb2579
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发表时间：
2012-10-01
影响因子：
21.3
通讯作者：
Choudhary, Chunaram
中科院分区：
文献类型：
--
作者：
Povlsen, Lou K.;Beli, Petra;Choudhary, Chunaram
蛋白质泛素化已成为DNA损伤信号传导和修复途径中的关键调节机制。我们报告了紫外线照射后泛素化变化的蛋白质组范围内，特定位点的调查，确定了许多上调和下调的泛素化位点的已知组件的DNA损伤信号，以及蛋白质没有以前牵连在这个过程中。我们的研究结果揭示了PCNA相关因子PAF 15（p15（PAF）/KIAA 0101）泛素化在DNA复制过程中的关键作用。在未受干扰的S期，染色质相关的PAF 15被修饰的双单泛素化的赖氨酸15和24模板通过PCNA结合。复制阻断触发快速的、蛋白酶体依赖性的从PCNA中去除赖氨酸15/24-泛素化的PAF 15，通过允许跨病变DNA合成聚合酶pol eta在停滞的复制体中募集到单泛素化的PCNA来促进绕过复制叉阻断病变。我们的研究结果表明，遍在蛋白信号广泛参与基因毒性应激反应，并确定了当DNA复制受到挑战时，动态PAF 15遍在蛋白化在保护基因组完整性方面的关键功能。
Protein ubiquitylation has emerged as a key regulatory mechanism in DNA-damage signalling and repair pathways. We report a proteome-wide, site-specific survey of ubiquitylation changes after ultraviolet irradiation, identifying numerous upregulated and downregulated ubiquitylation sites on known components of DNA-damage signalling, as well as on proteins not previously implicated in this process. Our results uncover a critical role for PCNA-associated factor PAF15 (p15(PAF)/KIAA0101) ubiquitylation during DNA replication. During unperturbed S phase, chromatin-associated PAF15 is modified by double mono-ubiquitylation of Lys 15 and 24 templated through PCNA binding. Replication blocks trigger rapid, proteasome-dependent removal of Lys 15/24-ubiquitylated PAF15 from PCNA, facilitating bypass of replication-fork-blocking lesions by allowing recruitment of translesion DNA synthesis polymerase pol eta to mono-ubiquitylated PCNA at stalled replisomes. Our findings demonstrate widespread involvement of ubiquitin signalling in genotoxic-stress responses and identify a critical function for dynamic PAF15 ubiquitylation in safeguarding genome integrity when DNA replication is challenged.