Processive DNA synthesis is associated with localized decompaction of constitutive heterochromatin at the sites of DNA replication and repair
Processive DNA synthesis is associated with localized decompaction of constitutive heterochromatin at the sites of DNA replication and repair
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DOI：
10.1080/19491034.2019.1688932
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发表时间：
2019-01-01
期刊：
影响因子：
3.7
通讯作者：
Cardoso, M. Cristina
中科院分区：
文献类型：
--
作者：
Chagin, Vadim O.;Reinhart, Britta;Cardoso, M. Cristina
本构异染色质被认为是一个功能惰性的基因组室，对其结构和稳定性很重要。这种稳定的结构是如何维持的还不是很清楚。在这里，我们应用四种不同的可视化方案来标记它，并研究其在DNA复制和修复过程中的动力学。我们表明，复制体在异染色质上以一种时间有序的方式组装。此外，异染色质在DNA合成的活性位点局部经历短暂的分解。使用选择性激光微照射条件，通过DNA合成修复损伤，我们测量了异染色质的类似局部分解。在这两种情况下，我们都无法观察到异染色质向结构域表面的大规模运动。相反，过程DNA合成机器在复制/修复位点组装。总的来说，我们的数据与DNA复制/修复沿着染色质以一种动态模式进行的进展是一致的，这种模式具有局部和短暂的分解，而不是全局重塑整个异染色质室。
Constitutive heterochromatin is considered as a functionally inert genome compartment, important for its architecture and stability. How such stable structure is maintained is not well understood. Here, we apply four different visualization schemes to label it and investigate its dynamics during DNA replication and repair. We show that replisomes assemble over the heterochromatin in a temporally ordered manner. Furthermore, heterochromatin undergoes transient decompaction locally at the active sites of DNA synthesis. Using selective laser microirradiation conditions that lead to damage repaired via processive DNA synthesis, we measured similarly local decompaction of heterochromatin. In both cases, we could not observe large-scale movement of heterochromatin to the domain surface. Instead, the processive DNA synthesis machinery assembled at the replication/repair sites. Altogether, our data are compatible with a progression of DNA replication/repair along the chromatin in a dynamic mode with localized and transient decompaction that does not globally remodels the whole heterochromatin compartment.