Arabidopsis RAD51, RAD51C and XRCC3 proteins form a complex and facilitate RAD51 localization on chromosomes for meiotic recombination.
Arabidopsis RAD51, RAD51C and XRCC3 proteins form a complex and facilitate RAD51 localization on chromosomes for meiotic recombination.
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拟南芥 RAD51、RAD51C 和 XRCC3 蛋白形成复合物，促进 RAD51 在染色体上定位以进行减数分裂重组。
DOI：
10.1371/journal.pgen.1006827
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发表时间：
2017-05
期刊：
影响因子：
4.5
通讯作者：
Wang Y
中科院分区：
文献类型：
--
作者：
Su H;Cheng Z;Huang J;Lin J;Copenhaver GP;Ma H;Wang Y
减数分裂重组是植物和其他真核生物中同源染色体正确分离所必需的。真核生物的RAD 51基因家族有7个古老的旁系同源基因，在有丝分裂和减数分裂重组中发挥重要作用。哺乳动物RAD 51同源物RAD 51 C和XRCC 3中的突变导致胚胎致死。在模式植物拟南芥（Arabidopsis thaliana）中，RAD 51 C和XRCC 3同源物对于营养体发育不是必需的，但对于体细胞和减数分裂重组都是必需的，但RAD 51 C和XRCC 3在减数分裂重组中的机制尚不清楚。非致死拟南芥rad 51 c和xrcc 3无效突变体提供了一个机会，研究其减数分裂功能。在这里，我们表明，AtRAD 51 C和AtXRCC 3是RAD 51依赖的减数分裂重组途径的组成部分，并需要正常AtRAD 51减数分裂染色体上的本地化。此外，AtRAD 51 C在体外和体内与AtRAD 51和AtXRCC 3相互作用，表明这些蛋白质形成复合物。AtRAD 51焦点在性母细胞的atrad 51，atrad 51 c，atxrcc 3单，双和三杂合突变体的比较进一步支持AtRAD 51 C和AtXRCC 3之间的相互作用，增强AtRAD 51的本地化。此外，atrad 51 c-/+ atxrcc 3-/+双突变体和atrad 51-/+ atrad 51 c-/+ atxrcc 3-/+三杂合突变体在减数分裂重组中存在缺陷，这表明AtRAD 51 C-AtXRCC 3复合物在减数分裂重组中的作用部分依赖于AtRAD 51。总之，我们的研究结果支持一个模型，其中RAD 51 C-XRCC 3复合物和RAD 51之间的直接相互作用促进RAD 51的减数分裂染色体上的定位和RAD 51依赖的减数分裂重组。最后，我们假设由RAD 51 C-XRCC 3复合物促进的RAD 51功能的维持在真核生物中可能是高度保守的。
Meiotic recombination is required for proper homologous chromosome segregation in plants and other eukaryotes. The eukaryotic RAD51 gene family has seven ancient paralogs with important roles in mitotic and meiotic recombination. Mutations in mammalian RAD51 homologs RAD51C and XRCC3 lead to embryonic lethality. In the model plant Arabidopsis thaliana, RAD51C and XRCC3 homologs are not essential for vegetative development but are each required for somatic and meiotic recombination, but the mechanism of RAD51C and XRCC3 in meiotic recombination is unclear. The non-lethal Arabidopsis rad51c and xrcc3 null mutants provide an opportunity to study their meiotic functions. Here, we show that AtRAD51C and AtXRCC3 are components of the RAD51-dependent meiotic recombination pathway and required for normal AtRAD51 localization on meiotic chromosomes. In addition, AtRAD51C interacts with both AtRAD51 and AtXRCC3 in vitro and in vivo, suggesting that these proteins form a complex (es). Comparison of AtRAD51 foci in meiocytes from atrad51, atrad51c, and atxrcc3 single, double and triple heterozygous mutants further supports an interaction between AtRAD51C and AtXRCC3 that enhances AtRAD51 localization. Moreover, atrad51c-/+ atxrcc3-/+ double and atrad51-/+ atrad51c-/+ atxrcc3-/+ triple heterozygous mutants have defects in meiotic recombination, suggesting the role of the AtRAD51C-AtXRCC3 complex in meiotic recombination is in part AtRAD51-dependent. Together, our results support a model in which direct interactions between the RAD51C-XRCC3 complex and RAD51 facilitate RAD51 localization on meiotic chromosomes and RAD51-dependent meiotic recombination. Finally, we hypothesize that maintenance of RAD51 function facilitated by the RAD51C-XRCC3 complex could be highly conserved in eukaryotes.