Stable interactions between DNA polymerase δ catalytic and structural subunits are essential for efficient DNA repair
Stable interactions between DNA polymerase δ catalytic and structural subunits are essential for efficient DNA repair
复制标题
DOI：
10.1016/j.dnarep.2010.07.013
复制
发表时间：
2010-10-05
期刊：
影响因子：
3.8
通讯作者：
Maloisel, Laurent
中科院分区：
文献类型：
--
作者：
Brocas, Clementine;Charbonnier, Jean-Baptiste;Maloisel, Laurent
真核 DNA 聚合酶 delta (Pol delta) 活性对于染色体复制和 DNA 修复至关重要，因此在基因组稳定性中起着至关重要的作用。 在酿酒酵母中，Pol delta 是一种异三聚体复合物，由催化亚基 Pol3、结构 B 亚基 Pol31 和 Pol32 组成，另外一个辅助亚基 Pol3 与 Pol31 由于其 C 端结构域 (CTD) 而这种相互作用在 DNA 复制和 DNA 修复中都具有重要的功能。有趣的是，在 pol3-ct 突变体中删除最后四个 C 端 Pol3 残基 LSKW 不会影响 DNA 复制，但会导致同源重组和断裂诱导复制 (BIR) 修复途径中的缺陷。与 pol3-ct 相关的缺陷可能会导致 然而，我们发现，LSKW 基序是 Pol3 C 末端和 Pol31 之间相互作用所必需的。这种相互作用的丧失在体内是相关的，因为我们发现 pol3-ct 本身赋予 HU 敏感性，并通过 POL32 缺失赋予合成致死性。此外，pol3-ct 显示遗传相互作用，包括抑制和合成 结构分析表明，Pol δ 的 B 亚基在其表面显示出一个主要保守区域，并且 pol31 等位基因与 pol3-ct 相互作用，对应于位于该特定区域的 Pol31 氨基酸的取代。将我们的 Pol31 模型叠加在系统发育相关的 DNA 聚合酶 α (Pol alpha) 的 3D 结构上表明 Pol3 CTD 与 Pol31 的保守区域相互作用，从而为理解 pol3-ct 相关缺陷提供了分子基础 总而言之，我们的数据强调了 DNA 修复中对 Pol δ 复合物稳定性的严格依赖 (C) 2010 Elsevier B V 保留所有权利
Eukaryotic DNA polymerase delta (Pol delta) activity is crucial for chromosome replication and DNA repair and thus, plays an essential role in genome stability In Saccharomyces cerevisme, Pol delta is a heterotrimeric complex composed of the catalytic subunit Pol3, the structural B subunit Pol31, and Pol32, an additional auxiliary subunit Pol3 interacts with Pol31 thanks to its C-terminal domain (CTD) and this interaction is of functional importance both in DNA replication and DNA repair Interestingly, deletion of the last four C-terminal Pol3 residues, LSKW, in the pol3-ct mutant does not affect DNA replication but leads to defects in homologous recombination and in break-induced replication (BIR) repair pathways The defect associated with pol3-ct could result from a defective interaction between Pol delta and a protein involved in recombination However, we show that the LSKW motif is required for the interaction between Pol3 C-terminal end and Pol31 This loss of interaction is relevant in vivo since we found that pol3-ct confers HU sensitivity on its own and synthetic lethality with a POL32 deletion Moreover, pol3-ct shows genetic interactions, both suppression and synthetic lethality, with POL31 mutant alleles Structural analyses indicate that the B subunit of Pol delta displays a major conserved region at its surface and that pol31 alleles interacting with pol3-ct, correspond to substitutions of Pol31 amino acids that are situated in this particular region Superimposition of our Pol31 model on the 3D architecture of the phylogenetically related DNA polymerase alpha (Pol alpha) suggests that Pol3 CTD interacts with the conserved region of Pol31, thus providing a molecular basis to understand the defects associated with pol3-ct Taken together, our data highlight a stringent dependence on Pol delta complex stability in DNA repair (C) 2010 Elsevier B V All rights reserved