Distinct roles of DNA polymerases delta and epsilon at the replication fork in Xenopus egg extracts
Distinct roles of DNA polymerases delta and epsilon at the replication fork in Xenopus egg extracts
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DOI：
10.1111/j.1356-9597.2004.00716.x
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发表时间：
2004-03-01
期刊：
影响因子：
2.1
通讯作者：
Waga, S
中科院分区：
文献类型：
--
作者：
Fukui, T;Yamauchi, K;Waga, S
DNA聚合酶Delta和Epsilon（Poldelta和polepsilon）被广泛认为是真核细胞中DNA复制过程中伸长的主要DNA聚合酶。但是，这些聚合酶的确切作用尚不清楚。在这里，我们比较分析了对Poldelta或polepsilon免疫部门的爪蟾卵提取物中的DNA复制。两种聚合酶的耗竭导致DNA合成和短期新生DNA产物的积累显着降低，表明伸长缺陷。此外，Poldelta的耗竭会导致伸长率更严重，如短的新生DNA产物和单链DNA间隙的持续积累所示，以及通过在滞后链合成过程中更频繁地起作用的复制蛋白的染色质结合。因此，我们的数据强烈表明Poldelta对于滞后链的合成至关重要，并且Polepsilon不能代替Poldelta的这种功能。
DNA polymerases delta and epsilon (Poldelta and Polepsilon) are widely thought to be the major DNA polymerases that function in elongation during DNA replication in eukaryotic cells. However, the precise roles of these polymerases are still unclear. Here we comparatively analysed DNA replication in Xenopus egg extracts in which Poldelta or Polepsilon was immunodepleted. Depletion of either polymerase resulted in a significant decrease in DNA synthesis and accumulation of short nascent DNA products, indicating an elongation defect. Moreover, Poldelta depletion caused a more severe defect in elongation, as shown by sustained accumulation of both short nascent DNA products and single-stranded DNA gaps, and also by elevated chromatin binding of replication proteins that function more frequently during lagging strand synthesis. Therefore, our data strongly suggest the possibilities that Poldelta is essential for lagging strand synthesis and that this function of Poldelta cannot be substituted for by Polepsilon.