The Configuration of RPA, RAD51, and DMC1 Binding in Meiosis Reveals the Nature of Critical Recombination Intermediates
The Configuration of RPA, RAD51, and DMC1 Binding in Meiosis Reveals the Nature of Critical Recombination Intermediates
复制标题
减数分裂中 RPA、RAD51 和 DMC1 结合的构型揭示了关键重组中间体的本质
DOI：
10.1016/j.molcel.2020.06.015
复制
发表时间：
2020-08-20
期刊：
影响因子：
16
通讯作者：
Donnelly, Peter
中科院分区：
文献类型：
--
作者：
Hinch, Anjali Gupta;Becker, Philipp W.;Donnelly, Peter
减数分裂重组通过RPA、RAD 51和DMC 1与程序性DNA双链断裂形成后产生的单链DNA（ssDNA）底物结合进行。在这里，我们报告了RPA和RAD 51在减数分裂中的高分辨率体内地图，使用基因工程杂交小鼠将其结合位置和寿命映射到单个同源染色体。连同高分辨率显微镜和DMC 1结合地图，我们表明，DMC 1和RAD 51有不同的空间定位的ssDNA：DMC 1结合附近的断裂位点，和RAD 51结合远离it. We之间的同源重组中间体结合RPA在体内，与预期的关键位移环（D-环）中间体的属性。这些数据支持的假设，DMC 1，而不是RAD 51，在哺乳动物减数分裂中进行链交换。RPA结合的D-环可以被解析为交叉或非交叉，但交叉目的地的D-环可能具有更长的寿命。D环在大小上类似于交叉基因转换，但它们在两种修复途径中的程度相似。
Meiotic recombination proceeds via binding of RPA, RAD51, and DMC1 to single-stranded DNA (ssDNA) substrates created after formation of programmed DNA double-strand breaks. Here we report high-resolution in vivo maps of RPA and RAD51 in meiosis, mapping their binding locations and lifespans to individual homologous chromosomes using a genetically engineered hybrid mouse. Together with high-resolution microscopy and DMC1 binding maps, we show that DMC1 and RAD51 have distinct spatial localization on ssDNA: DMC1 binds near the break site, and RAD51 binds away from it. We characterize inter-homolog recombination intermediates bound by RPA in vivo, with properties expected for the critical displacement loop (D-loop) intermediates. These data support the hypothesis that DMC1, not RAD51, performs strand exchange in mammalian meiosis. RPA-bound D-loops can be resolved as crossovers or non-crossovers, but crossover-destined D-loops may have longer lifespans. D-loops resemble crossover gene conversions in size, but their extent is similar in both repair pathways.