Budding yeast mcm10 /dna43 mutant requires a novel repair pathway for viability
Budding yeast mcm10 /dna43 mutant requires a novel repair pathway for viability
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DOI：
10.1046/j.1365-2443.2003.00648.x
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发表时间：
2003-05-01
期刊：
影响因子：
2.1
通讯作者：
Sugino, A
中科院分区：
文献类型：
--
作者：
Araki, Y;Kawasaki, Y;Sugino, A
背景：MCM 10是酿酒酵母染色体DNA复制启动所必需的。Mcm 10 p与复制前复合物（Mcm 2-Mcm 7复合物和起源识别复合物）的组分以及起始前复合物组分（Cdc 45 p）在功能上相互作用，表明它可能是前RC和前IC的组分。二维凝胶电泳分析表明，Mcm 10 p不仅需要在复制起点的DNA合成的起始，但也为复制叉在起点顺利通过。遗传分析表明，MCM 10相互作用的组件的延伸机械，如Poldelta和Polymerase，这表明它可能发挥作用，在延长replication.Results：我们发现，MCM 10突变导致复制叉暂停不仅在潜在的活跃的起源，但也在沉默的起源。我们筛选了与mcm 10 -1组合致死的突变体，并获得了7个突变体，命名为slm 1-slm 6，分别用于bar下的（s）和bar下的（m）。这些突变体包括六个互补组，可以分为三类。1类包括编码前RC和前IC组分的基因，并由分别与MCM 7、MCM 2和CDC 45等位的SLM 3、4和5表示。第2类包括在滞后链合成中参与冈崎片段加工的基因，并由与DNA 2等位的SLM 1代表。第3类包括以SLM 2和SLM 6为代表的新的DNA修复基因。结论：mcm 10 -1突变体的生存能力依赖于一种新的修复途径，该途径可能参与解决积累的复制中间体或复制叉阻断引起的损伤。这些结果是一致的假设，Mcm 10 p是通过复制叉所需的障碍，如由前RC组装在活跃或不活跃的复制起点。
Background: MCM10 is essential for the initiation of chromosomal DNA replication in Saccharomyces cerevisiae . Mcm10p functionally interacts with components of the pre-replicative complex (Mcm2-Mcm7 complex and origin recognition complex) as well as the pre-initiation complex component (Cdc45p) suggesting that it may be a component of the pre-RC as well as the pre-IC. Two-dimensional gel electrophoresis analysis showed that Mcm10p is required not only for the initiation of DNA synthesis at replication origins but also for the smooth passage of replication forks at origins. Genetic analysis showed that MCM10 interacts with components of the elongation machinery such as Poldelta and Polepsilon, suggesting that it may play a role in elongation replication.Results: We show that the mcm10 mutation causes replication fork pausing not only at potentially active origins but also at silent origins. We screened for mutations that are lethal in combination with mcm10-1 and obtained seven mutants named slm1-slm6 for (s) under bar ynthetically (l) under bar ethal with (m) under bar cm10 . These mutants comprised six complementation groups that can be divided into three classes. Class 1 includes genes that encode components of the pre-RC and pre-IC and are represented by SLM3 , 4 and 5 which are allelic to MCM7 , MCM2 and CDC45 , respectively. Class 2 includes genes involved in the processing of Okazaki fragments in lagging strand synthesis and is represented by SLM1 , which is allelic to DNA2 . Class 3 includes novel DNA repair genes represented by SLM2 and SLM6 .Conclusions: The viability of the mcm10-1 mutant is dependent on a novel repair pathway that may participate either in resolving accumulated replication intermediates or the damage caused by blocked replication forks. These results are consistent with the hypothesis that Mcm10p is required for the passage of replication forks through obstacles such as those created by pre-RCs assembled at active or inactive replication origins.