Position effects influencing intrachromosomal repair of a double-strand break in budding yeast
Position effects influencing intrachromosomal repair of a double-strand break in budding yeast
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DOI：
10.1371/journal.pone.0180994
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发表时间：
2017-07-11
期刊：
影响因子：
3.7
通讯作者：
Haber, James E.
中科院分区：
文献类型：
--
作者：
Wang, Ruoxi W.;Lee, Cheng-Sheng;Haber, James E.
通过异位同源供体序列修复双链断裂（DSB）受制于单倍体芽殖酵母细胞核中染色体的三维排列。染色体间重组的数据表明，寻找同源性是通过随机碰撞过程完成的，受供体和受体序列的接触概率的强烈影响。在这里，我们探讨如何重组发生在同一染色体上，是否有额外的限制修复。具体而言，我们研究了染色体内修复如何受到供体序列沿着813 kb的2号染色体（Chr2）的位置的影响，在右臂（位置625 kb）上产生位点特异性DSB。修复与染色体构象捕获为基础的研究确定的接触频率（r = 0.85）。此外，有一个深刻的约束所施加的锚定的着丝粒（CEN2，位置238 kb）的主轴杆体。在CEN2两侧相同距离处的序列在与位于一个臂上更远侧的DSB重组时受到同等限制，这表明与DSB相对臂上的序列在与DSB的相互作用中不受其他限制。可以通过诱导转录通过着丝粒到TCEN2拴系部分解除着丝粒约束。在二倍体细胞中，DSB通过其等位基因供体的修复受到异位染色体内供体的存在和位置的强烈影响。
Repair of a double-strand break (DSB) by an ectopic homologous donor sequence is subject to the three-dimensional arrangement of chromosomes in the nucleus of haploid budding yeast. The data for interchromosomal recombination suggest that searching for homology is accomplished by a random collision process, strongly influenced by the contact probability of the donor and recipient sequences. Here we explore how recombination occurs on the same chromosome and whether there are additional constraints imposed on repair. Specifically, we examined how intrachromosomal repair is affected by the location of the donor sequence along the 813-kb chromosome 2 (Chr2), with a site-specific DSB created on the right arm (position 625 kb). Repair correlates well with contact frequencies determined by chromosome conformation capture-based studies (r = 0.85). Moreover, there is a profound constraint imposed by the anchoring of the centromere (CEN2, position 238 kb) to the spindle pole body. Sequences at the same distance on either side of CEN2 are equivalently constrained in recombining with a DSB located more distally on one arm, suggesting that sequences on the opposite arm from the DSB are not otherwise constrained in their interaction with the DSB. The centromere constraint can be partially relieved by inducing transcription through the centromere to inactivate CEN2 tethering. In diploid cells, repair of a DSB via its allelic donor is strongly influenced by the presence and the position of an ectopic intrachromosomal donor.