Ubiquitin-dependent DNA damage bypass is separable from genome replication.
Ubiquitin-dependent DNA damage bypass is separable from genome replication.
复制标题
作者：
复制后修复（PRR）是一种允许细胞在DNA复制期间绕过或克服病变的途径。在真核生物中，损伤旁路通过复制钳PCNA的泛素化通过RAD6途径的组分激活。而PCNA的单泛素化允许损伤耐受DNA聚合酶的诱变translesion合成，多泛素化是一个无错误的途径，可能涉及到未受损的姐妹染色单体的模板开关所需的。PRR事件在细胞周期中的时间和它们相对于复制叉的位置，以及PCNA泛素化下游所需的因素，都仍然没有得到很好的表征。在这里，我们证明了RAD6通路在S期正常运作。然而，使用诱导系统的DNA损伤旁路在芽殖酵母，我们表明，该过程是可分离的时间和空间从基因组复制，从而允许直接可视化和定量生产PRR大片。我们发现，在S期紫外线辐射诱导的病变期间和之后，主要通过translesion合成绕过，而无错误的途径作为备份系统。我们的方法首次揭示了PRR束在同步细胞群中的分布。它将允许对细胞如何在复制期间和复制后管理其基因组损伤的处理进行深入的机制分析。
Postreplication repair (PRR) is a pathway that allows cells to bypass or overcome lesions during DNA replication. In eukaryotes, damage bypass is activated by ubiquitylation of the replication clamp PCNA through components of the RAD6 pathway. Whereas monoubiquitylation of PCNA allows mutagenic translesion synthesis by damage-tolerant DNA polymerases, polyubiquitylation is required for an error-free pathway that likely involves a template switch to the undamaged sister chromatid. Both the timing of PRR events during the cell cycle and their location relative to replication forks, as well as the factors required downstream of PCNA ubiquitylation, have remained poorly characterised. Here we demonstrate that the RAD6 pathway normally operates during S phase. However, using an inducible system of DNA damage bypass in budding yeast, we show that the process is separable in time and space from genome replication, thus allowing direct visualisation and quantification of productive PRR tracts. We found that both during and after S phase ultraviolet radiation-induced lesions are bypassed predominantly via translesion synthesis, whereas the error-free pathway functions as a backup system. Our approach has for the first time revealed the distribution of PRR tracts in a synchronised cell population. It will allow an in-depth mechanistic analysis of how cells manage the processing of lesions to their genomes during and after replication.
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DOI：
10.1073/pnas.0505949102
发表时间：
2005-12-20
影响因子：
11.1
作者：
Garg, P;Burgers, PM
通讯作者：
Burgers, PM
影响因子：
2.6
作者：
Viggiani, Christopher J.;Aparicio, Oscar M.
通讯作者：
Aparicio, Oscar M.
影响因子：
64.8
作者：
Stelter, P;Ulrich, HD
通讯作者：
Ulrich, HD
影响因子：
16
作者：
Kannouche, PL;Wing, J;Lehmann, AR
通讯作者：
Lehmann, AR
影响因子：
16
作者：
Edmunds, Charlotte E.;Simpson, Laura J.;Sale, Julian E.
通讯作者：
Sale, Julian E.