Porphobilinogen deaminase HEMC interacts with the PPR-protein AtECB2 for chloroplast RNA editing
Porphobilinogen deaminase HEMC interacts with the PPR-protein AtECB2 for chloroplast RNA editing
复制标题
胆色素原脱氨酶 HEMC 与 PPR 蛋白 AtECB2 相互作用进行叶绿体 RNA 编辑
DOI：
10.1111/tpj.13672
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发表时间：
2017-11-01
期刊：
影响因子：
7.2
通讯作者：
Yang, Zhong-Nan
中科院分区：
文献类型：
--
作者：
Huang, Chao;Yu, Qing-Bo;Yang, Zhong-Nan
五肽重复 DYW 蛋白 AtECB2 影响 7 个位点的质体 RNA 编辑，包括 accD-794、accD-1568、ndhF-290、ndhG-50、petL-5、rpoA-200 和 rpoC1-488。为了了解其参与 RNA 编辑的机制，我们构建了一个转基因系，其中 AtECB2 与 4xMYC 标签融合，可以补充 atecb2 表型。 RNA免疫沉淀分析表明AtECB2与accD、ndhF、ndhG和petL的转录本相关。免疫共沉淀和质谱实验表明，多个细胞器 RNA 编辑因子 2 (MORF2) 和胆色素原脱氨酶 HEMC 与 AtECB2 相关。生化分析表明AtECB2通过其E结构域直接与HEMC相互作用，而HEMC与MORF8/RIP1相互作用。删除分析表明 E 结构域对于 RNA 编辑至关重要。 hemc-1 突变体表现出白化和幼苗致死表型。在atecb2中受影响的七个编辑位点中，hemc-1中accD-794和ndhF-290的编辑也减少了。 RNA免疫沉淀分析表明HEMC与ndhF转录本的编辑位点相关。这些结果表明，HEMC 和多种细胞器 RNA 编辑因子 (MORF) 蛋白均与 AtECB2 相关，用于质体中的 RNA 编辑。 意义说明 PPO1 是叶绿素生物合成途径中的一种酶，据报道对于质体 RNA 编辑至关重要。该途径中的另一种酶 HEMC 现在也被发现参与质体 RNA 编辑。这项研究进一步深入了解叶绿素生物合成和质体 RNA 编辑之间的协调。
The pentatricopeptide repeat-DYW protein AtECB2 affects plastid RNA editing at seven sites, including accD-794, accD-1568, ndhF-290, ndhG-50, petL-5, rpoA-200 and rpoC1-488. To understand the mechanism of its involvement in RNA editing, a transgenic line was constructed with AtECB2 fused to a 4xMYC tag that could complement the atecb2 phenotype. RNA immunoprecipitation analysis indicated that AtECB2 is associated with the transcripts of accD, ndhF, ndhG and petL. Co-immunoprecipitation and mass spectrometry experiments showed that multiple organelle RNA editing factor 2 (MORF2) and porphobilinogen deaminase HEMC are associated with AtECB2. Biochemical analysis showed that AtECB2 directly interacts with HEMC through its E domain, while HEMC interacts with MORF8/RIP1. Deletion analysis showed that the E domain is essential for RNA editing. The hemc-1 mutant showed an albino and seedling-lethal phenotype. Of the seven editing sites affected in atecb2, the editing of accD-794 and ndhF-290 was also reduced in hemc-1. RNA immunoprecipitation analysis suggested that HEMC is associated with the editing sites of ndhF transcripts. These results showed that both HEMC and multiple organellar RNA editing factor (MORF) proteins are associated with AtECB2 for RNA editing in plastids.Significance Statement PPO1, an enzyme in the chlorophyll biosynthetic pathway, was reported to be essential for plastid RNA editing. Another enzyme in this pathway, HEMC, has now also been found to be involved in plastid RNA editing. This research provides further insight into the coordination between chlorophyll biosynthesis and plastid RNA editing.