Roles of DNA polymerases delta and epsilon in replication, repair, and genomic fidelity

摘要 在真核生物中，DNA 聚合酶 (Pols)  和  在复制中发挥着重要作用，但是这些 Pols 是如何发挥作用的？ 对于主要 DNA 链复制的贡献仍不清楚。虽然被广泛接受的模型 假设 Pol 复制前导链，Pol 复制滞后链，我们最近发表 有证据表明 Pol 可以复制前导 DNA 链和滞后 DNA 链。尽管如此，重要的问题 关于它们在复制中的作用仍有待解决。在这里我们提出了一些极具创新性的 明确建立 Pol 和 Pol 在复制中的作用的想法和实验方法。至 确定 Pol 或 Pol 是否复制前导链，在目标 1 中，我们将分析 Pol 生成的错误 基因中的两条 DNA 链位于不同的染色体位点，并且在许多不同的基因组范围内 酵母菌株，我们还将检查引导台上是否出现 Pol 产生的错误；在目标 2 中，我们 将利用 Pol 和 Pol 的 PCNA 结合域的突变来确定 Pol 是否在 复制两条 DNA 链或 Pol 是否复制前导链，我们将进行研究 分析pol2M-644G突变表型和核酸外切酶缺陷pol2-4的遗传基础 Pol 突变等位基因；在目标 3 中，我们将确定是否如我们的遗传学研究所示，Pol 在重组和错配修复过程中，而不是在前导链上整合 rNMP 复制。总而言之，我们期望拟议的研究将解决与 Pols  和  在复制中的作用，它们将对 DNA 复制和相关 DNA 产生重要影响 修复过程以及对这些 Pols 在基因组保真度中的作用的理解。

Abstract In eukaryotes, DNA polymerases (Pols)  and  play important roles in replication, but how these Pols contribute to the replication of the leading DNA strand has remained unclear. While the widely accepted model posits that Pol replicates the leading strand and Pol replicates the lagging strand, we recently published evidence that Pol replicates both the leading and lagging DNA strands. Nevertheless, important issues pertaining to their roles in replication remain to be resolved. Here we propose a number of highly innovative ideas and experimental approaches to unambiguously establish the roles of Pol and Pol in replication. To determine whether Pol or Pol replicates the leading strand, in Aim 1 we will analyze Pol-generated errors on the two DNA strands in genes located at different chromosomal sites and genome-wide in a number of different yeast strains, and we will also examine whether Pol-generated errors occur on the leading stand; in Aim 2 we will use mutations in the PCNA binding domain of Pol and Pol to determine whether Pol plays a major role in replicating both DNA strands or whether Pol replicates the leading strand, and we will carry out studies to analyze the genetic basis of the mutator phenotype of the pol2M-644G and the exonuclease defective pol2-4 Pol mutant alleles; and in Aim 3, we will determine whether as indicated from our genetic studies, Pol incorporates rNMPs on the leading strand during its roles in recombination and mismatch repair, and not during replication. Altogether, we expect that the proposed studies will resolve the outstanding issues relating to the role of Pols  and  in replication, and they will have important bearing on DNA replication and associated DNA repair processes and on the understanding of the roles of these Pols in genomic fidelity.