The essential role of yeast topoisomerase III in meiosis depends on recombination
The essential role of yeast topoisomerase III in meiosis depends on recombination
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DOI：
10.1093/emboj/18.6.1701
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发表时间：
1999-03-15
期刊：
影响因子：
11.4
通讯作者：
Fabre, F
中科院分区：
文献类型：
--
作者：
Gangloff, S;de Massy, B;Fabre, F
TOP3基因突变的酵母细胞表现出广泛的表型，包括细胞周期改变、过度重组、基因表达异常、交配不良、染色体不稳定和缺乏孢子形成。对TOP 3在减数分裂过程中的作用的分析表明TOP 3 Δ突变体进入减数分裂并完成重组的初始步骤。然而，还原分裂并没有发生。SPO11基因的缺失可以阻止减数分裂I中同源染色体之间的重组，使top3 Delta突变体能够形成有活力的孢子，这表明成功完成重组需要Top3。拓扑异构酶活性参与该过程，因为细菌TopA在酵母top3 Delta突变体中的表达允许孢子形成。减数分裂阻滞也部分受到SGS1缺失的抑制，SGS1是编码与Top3相互作用的解旋酶的基因。我们提出了一个必不可少的作用Top3在减数分裂重组过程中产生的分子的加工。
Yeast cells mutant for TOP3, the gene encoding the evolutionary conserved type I-5' topoisomerase, display a wide range of phenotypes including altered cell cycle, hyper-recombination, abnormal gene expression, poor mating, chromosome instability and absence of sporulation, In this report, an analysis of the role of TOP3 in the meiotic process indicates that top3 Delta mutants enter meiosis and complete the initial steps of recombination. However, reductional division does not occur. Deletion of the SPO11 gene, which prevents recombination between homologous chromosomes in meiosis I division, allows top3 Delta mutants to form viable spores, indicating that Top3 is required to complete recombination successfully. A topoisomerase activity is involved in this process, since expression of bacterial TopA in yeast top3 Delta mutants permits sporulation. The meiotic block is also partially suppressed by a deletion of SGS1, a gene encoding a helicase that interacts with Top3. We propose an essential role for Top3 in the processing of molecules generated during meiotic recombination.