Mechanism of Dmc1-mediated Meiotic Recombination in Budding Yeast

同源重组在染色体的还原分离中起着关键作用， 减数分裂减数分裂重组是由DNA双链的程序诱导启动的 断裂（DSB），并涉及有丝分裂中DSB重组修复相关机制 细胞减数分裂重组受到独特的调控过程， 同源染色单体之间的重组，而不是姐妹染色单体，也调节 交叉型重组事件的频率，以确保所有同源染色体 对参与至少一个这样的事件。重组的中心步骤是同源 链侵入和交换。芽殖酵母和包括人类在内的许多其他生物 有一个专门的减数分裂重组酶，Dmc 1，催化减数分裂的中心步骤 涉及DNA序列同源性搜索的重组， 链交换以形成连接重组伴侣的杂交DNA区域。不同的 链交换蛋白Rad51催化有丝分裂重组的中心步骤。DMC1有 一组独特的减数分裂特异性辅助蛋白，但也受到有丝分裂的调控。 重组蛋白，包括有丝分裂重组酶Rad51。Rad51是由一个 在减数分裂过程中，有丝分裂中的酶转化为Dmc 1辅助蛋白。我们小组研究了 Dmc 1促进减数分裂重组的分子机制。我们寻求 了解Dmc 1的活性是如何由其每个辅助蛋白调节的。这一目标 通过结合各种先进的实验方法来实现。特别 重要的是我们小组在生物化学重组重组过程方面的独特努力 使用纯化的组分。为了补充我们的生化研究，我们首先开发了 研究减数分裂的结构和动力学所需的工具和方法 使用超分辨率光学显微镜观察重组体。我们的团队还使用分子 允许检测断裂和分支DNA重组的遗传技术 中间体，以及重组过程中发生的蛋白质-蛋白质相互作用 过程我们寻求联合收割机这些方法来揭示重要的机械特征， 重组过程包括控制它的调节机制。

Homologous recombination plays a critical role in reductional segregation of chromosomes in meiosis. Meiotic recombination is initiated by the programmed induction of DNA double strand breaks (DSBs) and involves a mechanism related to recombinational repair of DSBs in mitotic cells. Meiotic recombination is subject to unique regulatory processes that promote recombination between homologous chromatids rather than sister chromatids and also regulate the frequency of crossover type recombination events to ensure all homologous chromosome pairs engage in at least one such event. The central step of recombination is homologous strand invasion and exchange. Budding yeast and many other organisms including humans have a specialized meiotic recombinase, Dmc1, that catalyzes the central step of meiotic recombination which involves DNA sequence homology searching that culminates in DNA strand exchange to form regions of hybrid DNA that connect recombining partners. A different strand exchange protein, Rad51, catalyzes the central step of mitotic recombination. Dmc1 has a unique set of meiosis-specific accessory proteins, but is also regulated by mitotic recombination proteins, including the mitotic recombinase Rad51. Rad51 is converted from an enzyme in mitosis into to a Dmc1 accessory protein during meiosis. Our group studies the molecular mechanism through which Dmc1 promotes meiotic recombination. We seek to understand how Dmc1’s activity is regulated by each of its accessory proteins. This goal is achieved by combining a wide range of advanced experimental approaches. Of particular importance is our group’s unique effort to biochemically reconstitute the recombination process using purified components. To complement our biochemical studies, we were first to develop the tools and methods required to study the architecture and dynamics of meiotic recombinosomes using super-resolution light microscopy. Our group also employs molecular genetic techniques that allow detection of broken and branched DNA recombination intermediates, as well as the protein-protein interactions that occur during the recombination process. We seek to combine these approaches to uncover important mechanistic features of the recombination process including the regulatory mechanisms that control it.