Telomerase-null survivor screening identifies novel telomere recombination regulators.
Telomerase-null survivor screening identifies novel telomere recombination regulators.
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端粒酶无效幸存者筛选鉴定出新型端粒重组调节因子
DOI：
10.1371/journal.pgen.1003208
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发表时间：
2013
期刊：
影响因子：
4.5
通讯作者：
Zhou JQ
中科院分区：
文献类型：
--
作者：
Hu Y;Tang HB;Liu NN;Tong XJ;Dang W;Duan YM;Fu XH;Zhang Y;Peng J;Meng FL;Zhou JQ
端粒是在线性染色体末端发现的蛋白质-DNA结构，对基因组的完整性至关重要。端粒DNA长度主要由端粒酶维持。当端粒变得非常短时，缺乏端粒酶的细胞将经历衰老。在酿酒酵母中，非常小比例的缺乏端粒酶的细胞可以通过两种不同的同源重组途径延长端粒来保持活力。这些“幸存者”细胞分为I型或II型，每类幸存者具有不同的端粒DNA结构和遗传要求。为了阐明有助于幸存者产生的调控途径，我们敲除了280个端粒长度维持（TLM）基因突变体中的端粒酶RNA基因TLC 1，并检查了衰老后幸存者的端粒结构。我们发现了10个基因的新功能作用，这些基因影响I型与II型幸存者的比例，以及II型幸存者产生所需的22个基因。我们进一步证实了Pif 1解旋酶是I型重组所必需的，INO 80染色质重塑复合物极大地影响了I型幸存者的出现频率。最后，我们发现Rad 6介导的泛素化途径和KEOPS复合物是II型重组所必需的。我们的数据提供了一个独立的证据支持的想法，这些基因在端粒动力学中发挥重要作用。同源重组是生物体或细胞修复其基因组中受损DNA的一种手段。真核细胞染色体具有线性构型，两端是称为端粒的特殊DNA-蛋白质结构。端粒可以被细胞识别为DNA双链断裂，并通过同源重组进行修复。在面包酵母酿酒酵母（Saccharomyces cerevisiae）中，缺乏端粒酶（负责端粒DNA延长的主要因素）的细胞能够在端粒通过同源重组进行修复时逃脱衰老和细胞死亡。在这项研究中，我们进行了遗传筛选，以确定影响端粒DNA重组的基因。通过检查280个突变体的端粒结构，每个突变体都缺乏端粒长度维持基因和端粒酶RNA基因，我们确定了32个以前不知道参与端粒重组的基因。这些基因在多种细胞过程中发挥作用，我们的工作为在没有端粒酶的情况下调节端粒重组提供了新的见解。
Telomeres are protein–DNA structures found at the ends of linear chromosomes and are crucial for genome integrity. Telomeric DNA length is primarily maintained by the enzyme telomerase. Cells lacking telomerase will undergo senescence when telomeres become critically short. In Saccharomyces cerevisiae, a very small percentage of cells lacking telomerase can remain viable by lengthening telomeres via two distinct homologous recombination pathways. These “survivor” cells are classified as either Type I or Type II, with each class of survivor possessing distinct telomeric DNA structures and genetic requirements. To elucidate the regulatory pathways contributing to survivor generation, we knocked out the telomerase RNA gene TLC1 in 280 telomere-length-maintenance (TLM) gene mutants and examined telomere structures in post-senescent survivors. We uncovered new functional roles for 10 genes that affect the emerging ratio of Type I versus Type II survivors and 22 genes that are required for Type II survivor generation. We further verified that Pif1 helicase was required for Type I recombination and that the INO80 chromatin remodeling complex greatly affected the emerging frequency of Type I survivors. Finally, we found the Rad6-mediated ubiquitination pathway and the KEOPS complex were required for Type II recombination. Our data provide an independent line of evidence supporting the idea that these genes play important roles in telomere dynamics. Homologous recombination is a means for an organism or a cell to repair damaged DNA in its genome. Eukaryotic chromosomes have a linear configuration with two ends that are special DNA–protein structures called telomeres. Telomeres can be recognized by the cell as DNA double-strand breaks and subjected to repair by homologous recombination. In the baker's yeast Saccharomyces cerevisiae, cells that lack the enzyme telomerase, which is the primary factor responsible for telomeric DNA elongation, are able to escape senescence and cell death when telomeres undergo repair via homologous recombination. In this study, we have performed genetic screens to identify genes that affect telomeric DNA recombination. By examining the telomere structures in 280 mutants, each of which lacks both a telomere-length-maintenance gene and telomerase RNA gene, we identified 32 genes that were not previously known to be involved in telomere recombination. These genes have functions in a variety of cellular processes, and our work provides new insights into the regulation of telomere recombination in the absence of telomerase.
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影响因子：
64.5
作者：
Bao Y;Shen X
通讯作者：
Shen X
影响因子：
9.2
作者：
Huang, PH;Pryde, FE;Louis, EJ
通讯作者：
Louis, EJ
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11.4
作者：
Hecker, Arnaud;Lopreiato, Raffaele;van Tilbeurgh, Herman
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van Tilbeurgh, Herman
影响因子：
64.8
作者：
Boulé, JB;Vega, LR;Zakian, VA
通讯作者：
Zakian, VA
酵母PIF1P DNA解旋酶优先放出RNA DNA底物。
影响因子：
14.9
作者：
Boule, Jean-Baptiste;Zakian, Virginia A.
通讯作者：
Zakian, Virginia A.