Eme1 is involved in DNA damage processing and maintenance of genomic stability in mammalian cells
Eme1 is involved in DNA damage processing and maintenance of genomic stability in mammalian cells
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DOI：
10.1093/emboj/cdg580
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发表时间：
2003-11-17
期刊：
影响因子：
11.4
通讯作者：
Hakem, R
中科院分区：
文献类型：
--
作者：
Abraham, J;Lemmers, B;Hakem, R
酵母和人类Eme1蛋白与Mus81形成复合物，构成一种核酸内切酶，可切割分支DNA结构，尤其是在DNA复制停滞期间产生的那些结构。我们鉴定了小鼠Eme1，并表明它与Mus81相互作用形成一种复合物，该复合物在体外优先切割3' - flap结构和复制叉，而非霍利迪连接体。我们证明Eme1（-/-）胚胎干细胞（ES）对DNA交联剂丝裂霉素C和顺铂高度敏感，但对电离辐射、紫外线辐射和羟基脲处理仅轻度敏感。在同源重组过程（如基因打靶、基因转换和姐妹染色单体交换（SCE））中产生的DNA中间体的分解不需要哺乳动物Eme1。与Blm缺陷型ES细胞不同，仅在Eme1缺陷型细胞中诱导DNA损伤后才观察到SCE增加。最重要的是，Eme1缺陷导致自发的基因组不稳定性。这些结果表明，哺乳动物Eme1在DNA修复和基因组完整性的维持中起关键作用。
Yeast and human Eme1 protein, in complex with Mus81, constitute an endonuclease that cleaves branched DNA structures, especially those arising during stalled DNA replication. We identified mouse Eme1, and show that it interacts with Mus81 to form a complex that preferentially cleaves 3'-flap structures and replication forks rather than Holliday junctions in vitro. We demonstrate that Eme1(-/-) embryonic stem (ES) cells are hypersensitive to the DNA cross-linking agents mitomycin C and cisplatin, but only mildly sensitive to ionizing radiation, UV radiation and hydroxyurea treatment. Mammalian Eme1 is not required for the resolution of DNA intermediates that arise during homologous recombination processes such as gene targeting, gene conversion and sister chromatid exchange (SCE). Unlike Blm-deficient ES cells, increased SCE was seen only following induced DNA damage in Eme1-deficient cells. Most importantly, Eme1 deficiency led to spontaneous genomic instability. These results reveal that mammalian Eme1 plays a key role in DNA repair and the maintenance of genome integrity.