Rad52 forms DMA repair and recombination centers during S phase
Rad52 forms DMA repair and recombination centers during S phase
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DOI：
10.1073/pnas.121006298
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发表时间：
2001-07-17
影响因子：
11.1
通讯作者：
Mortensen, UH
中科院分区：
文献类型：
--
作者：
Lisby, M;Rothstein, R;Mortensen, UH
基因组完整性和稳定的遗传信息传播取决于许多DNA修复过程。不忠实地执行这些过程会导致遗传改变以及随后的癌症和其他遗传疾病的发展。在酿酒酵母的真核生糖糖疗法中，同源重组是修复DNA双链断裂的主要途径。 Rad52在该途径中扮演的关键作用归因于其寻求和介导同源DNA链退火的能力。在这项研究中，我们发现与绿色荧光蛋白（GFP）融合的酿酒酵母Rad52在DNA修复和重组中完全有效。通过伽马辐射，减数分裂或HO内切核酸酶诱导DNA双链断裂后，RAD52-GFP从弥漫性核分布重新定位到不同的焦点。有趣的是，在有丝分裂细胞的5期中，Rad52灶几乎完全形成，与重组修复和DNA复制之间的协调一致。通过在POL12-100复制突变体和MEC1 DNA损伤检查点突变体中观察到的RAD52焦点形成的频率的急剧增加，进一步加强了这一概念。此外，我们的数据表明，每个RAD52焦点都代表了能够处理多个DNA病变的重组维修中心。
Maintenance of genomic integrity and stable transmission of genetic information depend on a number of DNA repair processes. Failure to faithfully perform these processes can result in genetic alterations and subsequent development of cancer and other genetic diseases. In the eukaryote Saccharomyces cerevisiae, homologous recombination is the major pathway for repairing DNA double-strand breaks. The key role played by Rad52 in this pathway has been attributed to its ability to seek out and mediate annealing of homologous DNA strands. In this study, we find that S. cerevisiae Rad52 fused to green fluorescent protein (GFP) is fully functional in DNA repair and recombination. After induction of DNA double-strand breaks by gamma -irradiation, meiosis, or the HO endonuclease, Rad52-GFP relocalizes from a diffuse nuclear distribution to distinct foci. Interestingly, Rad52 foci are formed almost exclusively during the 5 phase of mitotic cells, consistent with coordination between recombinational repair and DNA replication. This notion is further strengthened by the dramatic increase in the frequency of Rad52 focus formation observed in a pol12-100 replication mutant and a mec1 DNA damage checkpoint mutant. Furthermore, our data indicate that each Rad52 focus represents a center of recombinational repair capable of processing multiple DNA lesions.