Pervasive and essential roles of the Top3-Rmi1 decatenase orchestrate recombination and facilitate chromosome segregation in meiosis.
Pervasive and essential roles of the Top3-Rmi1 decatenase orchestrate recombination and facilitate chromosome segregation in meiosis.
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DOI：
10.1016/j.molcel.2015.01.021
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发表时间：
2015-02-19
期刊：
影响因子：
16
通讯作者：
Hunter N
中科院分区：
文献类型：
--
作者：
Tang S;Wu MKY;Zhang R;Hunter N
Bloom's解旋酶同源基因Sgs 1在芽殖酵母减数分裂重组过程中协调接合分子中间体（JM）的形成和分解中起着重要作用。Sgs 1可以与I型拓扑异构酶Top3及其辅助因子Rmi 1结合形成保守的复合物，以其独特的使双霍利迪连接去连锁的能力而闻名。与预期相反，我们表明，链通过活性的Top3-Rmi 1所需的所有已知功能的SGS 1在减数分裂重组，包括通道JM进入生理交叉和非交叉途径，抑制非等位基因重组。我们推断Sgs 1总是在Sgs 1-Top3-Rmi 1复合物的背景下发挥作用，以调节减数分裂重组。此外，我们揭示了一个独特的后期作用Top3-Rmi 1在解决重组依赖的染色体缠结，使隔离在后期。令人惊讶的是，Sgs 1并不具有Top3-Rmi 1的这种重要作用。这些数据揭示了一个重要的和意想不到的普遍作用Top3-Rmi 1 decatenase减数分裂过程中。
The Bloom’s helicase ortholog, Sgs1, plays central roles to coordinate the formation and resolution of joint molecule intermediates (JMs) during meiotic recombination in budding yeast. Sgs1 can associate with type-I topoisomerase Top3 and its accessory factor Rmi1 to form a conserved complex best known for its unique ability to decatenate double-Holliday junctions. Contrary to expectations, we show that the strand-passage activity of Top3-Rmi1 is required for all known functions of Sgs1 in meiotic recombination, including channeling JMs into physiological crossover and noncrossover pathways, and suppression of non-allelic recombination. We infer that Sgs1 always functions in the context of the Sgs1-Top3-Rmi1 complex to regulate meiotic recombination. In addition, we reveal a distinct late role for Top3-Rmi1 in resolving recombination-dependent chromosome entanglements to allow segregation at anaphase. Surprisingly, Sgs1 does not share this essential role of Top3-Rmi1. These data reveal an essential and unexpectedly pervasive role for the Top3-Rmi1 decatenase during meiosis.