RECX interacts with mitochondrial RECA to maintain mitochondrial genome stability
RECX interacts with mitochondrial RECA to maintain mitochondrial genome stability
复制标题
RECX 与线粒体 RECA 相互作用以维持线粒体基因组稳定性
DOI：
10.1104/pp.18.00218
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发表时间：
2018
期刊：
影响因子：
7.4
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Odahara;M. and Sekine;Y.
叶绿体和线粒体基因组分别对光合作用和呼吸作用至关重要。RECA和RECG是细菌同源重组修复蛋白RecA和RecG的植物特异性同源物，通过抑制藓类小立碗藓中短分散重复序列（SDR）之间的异常重组来维持细胞器基因组的稳定性。在这项研究中，我们分析了植物特异性因子RECX，一种调节RecA的细菌RecX同源物。RECX与GFP融合，分别与线粒体RECA 1和叶绿体RECA 2共定位在线粒体和叶绿体类核上。RECX基因敲除（KO）和过表达（OEX）均不改变P.表型然而，线粒体DNA的分析表明，来自SDR之间重组的产物在RECXOX线粒体中显著增加，在RECXKO线粒体中适度增加。相反，叶绿体DNA的分析表明，RECXKO和OEX叶绿体中SDR之间重组的产物数量没有实质性的变化。酵母双杂交分析揭示了RECX和RECA1之间以及RECX和RECA2之间的相互作用。表达谱显示RECX与维持细胞器基因组和RECA1稳定性的因素之间呈正相关。总的来说，这些结果表明，RECX维持线粒体基因组的稳定性，可能通过调节RECA1活性，RECX的功能受损诱导线粒体基因组的不稳定性。
The chloroplast and mitochondrial genomes are essential for photosynthesis and respiration, respectively. RECA and RECG, which are plant-specific homologs of the bacterial homologous recombination repair proteins RecA and RecG, maintain organelle genome stability by suppressing aberrant recombination between short dispersed repeats (SDRs) in the mossPhyscomitrella patens. In this study, we analyzed the plant-specific factor RECX, a homolog of bacterial RecX that regulates RecA. RECX fused to GFP colocalized with mitochondrial RECA1 and chloroplast RECA2 on mitochondrial and chloroplast nucleoids, respectively. Knockout (KO) and overexpression (OEX) ofRECXdid not alter theP. patensmorphological phenotype. Analysis of mitochondrial DNA, however, showed that products from recombination between SDRs increased significantly inRECXOEX mitochondria and modestly inRECXKO mitochondria. By contrast, analysis of chloroplast DNA revealed no substantial alteration in the number of products from recombination between SDRs inRECXKO and OEX chloroplasts. Yeast two-hybrid analysis revealed interactions between RECX and RECA1 and between RECX and RECA2. Expression profiles showed a positive correlation betweenRECXand factors maintaining the stability of both organelle genomes andRECA1. Collectively, these results suggest that RECX maintains mitochondrial genome stability, likely by modulating RECA1 activity, and that the compromised function of RECX induces mitochondrial genome instability.