Cellular Dynamics of Rad51 and Rad54 in Response to Postreplicative Stress and DNA Damage in HeLa Cells
Cellular Dynamics of Rad51 and Rad54 in Response to Postreplicative Stress and DNA Damage in HeLa Cells
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DOI：
10.14348/molcells.2017.2275
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发表时间：
2017-02-01
影响因子：
3.8
通讯作者：
Kim, Keun P.
中科院分区：
文献类型：
--
作者：
Choi, Eui-Hwan;Yoon, Seobin;Kim, Keun P.
同源重组（HR）是维持基因组完整性和预防肿瘤抑制基因和原癌基因突变所必需的。Rad51和Rad54是应对真核生物复制应激和DNA断裂的关键HR因子。Rad51与单链DNA（ssDNA）结合形成突触前丝，促进同源性搜索和DNA链交换，Rad54刺激Rad51的链配对功能。在这里，我们研究了Rad51和Rad54在HeLa细胞周期中的分子动力学。这些细胞在整个细胞周期中组成性表达Rad51和Rad54，并且病灶的形成立即响应于各种类型的DNA损伤和复制应激而增加，除了咖啡因，其抑制Rad51依赖性HR途径。Rad51的缺失导致严重的缺陷，在应对postreplicative压力。因此，HeLa细胞在G2-M转变时被阻滞，尽管少量的Rad51稳定地维持在HeLa细胞中。我们的研究结果表明，细胞周期的进展和增殖的HeLa细胞可以严格控制的丰富的HR蛋白，这是必不可少的快速响应postreplicative应力和DNA损伤应力。
Homologous recombination (HR) is necessary for maintenance of genomic integrity and prevention of various mutations in tumor suppressor genes and proto-oncogenes. Rad51 and Rad54 are key HR factors that cope with replication stress and DNA breaks in eukaryotes. Rad51 binds to single-stranded DNA (ssDNA) to form the presynaptic filament that promotes a homology search and DNA strand exchange, and Rad54 stimulates the strand-pairing function of Rad51. Here, we studied the molecular dynamics of Rad51 and Rad54 during the cell cycle of HeLa cells. These cells constitutively express Rad51 and Rad54 throughout the entire cell cycle, and the formation of foci immediately increased in response to various types of DNA damage and replication stress, except for caffeine, which suppressed the Rad51-dependent HR pathway. Depletion of Rad51 caused severe defects in response to postreplicative stress. Accordingly, HeLa cells were arrested at the G2-M transition although a small amount of Rad51 was steadily maintained in HeLa cells. Our results suggest that cell cycle progression and proliferation of HeLa cells can be tightly controlled by the abundance of HR proteins, which are essential for the rapid response to postreplicative stress and DNA damage stress.