Involvement of mitochondrial-targeted RecA in the repair of mitochondrial DNA in the moss, Physcomitrella patens
Involvement of mitochondrial-targeted RecA in the repair of mitochondrial DNA in the moss, Physcomitrella patens
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DOI：
10.1266/ggs.82.43
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发表时间：
2007-02-01
影响因子：
1.1
通讯作者：
Sekine, Yasuhiko
中科院分区：
文献类型：
--
作者：
Odahara, Masaki;Inouye, Takayuki;Sekine, Yasuhiko
同源重组是一个普遍的过程，有助于遗传多样性和基因组的完整性。细菌型RecA普遍存在于所有细菌中，在同源重组中起着至关重要的作用。虽然RecA同源物也存在于植物线粒体中，但关于这些同源物的体内功能的报道很少。我们在藓类植物小立碗藓（Physcomitrella patens）的cDNA文库中发现了一个recA基因的直向同源物（命名为PprecA 1）。PpRecA 1的推定的细胞器靶向序列与GFP的N-末端融合导致PpRecA 1靶向线粒体。PprecA 1部分补充了大肠杆菌recA缺陷株中DNA损伤剂的作用。此外，通过用DNA损伤剂处理植物来诱导PprecA 1的表达。通过靶向置换破坏PprecA 1导致线粒体DNA从甲基甲磺酸损伤中恢复的速率较低。这是首次报道植物中细菌型recA基因无效突变体的特性。这些数据表明PprecA 1参与了P. patens线粒体DNA的修复。
Homologous recombination is a universal process that contributes to genetic diversity and genomic integrity. Bacterial-type RecA generally exists in all bacteria and plays a crucial role in homologous recombination. Although RecA homologues also exist in plant mitochondria, there have been few reports about the in vivo functions of these homologues. We identified a recA gene orthologue (named PprecA1) in a cDNA library of the moss, Physcomitrella patens. N-terminal fusion of the putative organellar targeting sequence of PpRecA1 to GFP caused a targeting of PpRecA1 to mitochondria. PprecA1 partially complemented the effects of a DNA damaging agent in an Escherichia coli recA deficient strain. Additionally, the expression of PprecA1 was induced by treating the plants with DNA damaging agents. Disruption of PprecA1 by targeted replacement resulted lower rate of the recovery of the mitochondrial DNA from methyl methan sulfonate damage. This is the first report about the characteristics of a null mutant of bacterial-type recA gene in plant. The data suggest that PprecA1 participates in the repair of mitochondrial DNA in P. patens.