Natural Variation in Arabidopsis Leads to the Identification of REME1, a Pentatricopeptide Repeat-DYW Protein Controlling the Editing of Mitochondrial Transcripts
Natural Variation in Arabidopsis Leads to the Identification of REME1, a Pentatricopeptide Repeat-DYW Protein Controlling the Editing of Mitochondrial Transcripts
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DOI：
10.1104/pp.110.165969
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发表时间：
2010-12-01
期刊：
影响因子：
7.4
通讯作者：
Hanson, Maureen
中科院分区：
文献类型：
--
作者：
Bentolila, Stephane;Knight, Walter;Hanson, Maureen
在维管植物中，细胞器 RNA 通过 C 至 U 碱基修饰进行编辑。数百个线粒体 C 残基被用于在开花植物中进行编辑。在这项研究中，我们利用编辑程度中自然发生的变异来鉴定线粒体编辑效率所需的必需基因1 (REME1)，这是拟南芥(Arabidopsis thaliana)五肽重复蛋白编码基因，属于DYW亚类，可促进不同线粒体转录本上至少两个C残基的编辑。位置克隆明确地将 REME1 鉴定为控制 nad2-558 编辑的基因。病毒诱导的 REME1 基因沉默证实了它在 nad2-558 编辑中的作用，并使我们能够将 orfX-552 鉴定为第二个 C，其编辑受 REME1 正向控制。 REME1 沉默的一个意想不到的结果是发现了许多线粒体 C 靶标，其编辑程度在沉默组织中表现出显着且可重复的增加。这种增加部分是由于病毒接种，部分是由于 REME1 特异性沉默。对 REME1 编码序列内插入 T-DNA 突变体的分析证实了病毒诱导的基因沉默实验的结果：nad2-558 和 orfX-552 的编辑程度降低，而 matR-1771 和 rpl5-92 两个位点的编辑程度增加。低编辑种质（Landsbergecta）的转基因互补将nad2-558和orfX-552的编辑恢复到高编辑种质（Columbia）型水平，甚至比Columbia更高的水平。转基因对 matR-1771 和 rpl5-92 的编辑程度没有影响。本报告中使用的策略和工具可用于识别影响植物线粒体编辑程度的其他基因。
In vascular plants, organelle RNAs are edited by C-to-U base modification. Hundreds of mitochondrial C residues are targeted for editing in flowering plants. In this study, we exploited naturally occurring variation in editing extent to identify Required for Efficiency of Mitochondrial Editing1 (REME1), an Arabidopsis (Arabidopsis thaliana) pentatricopeptide repeat protein-encoding gene belonging to the DYW subclass that promotes editing of at least two C residues on different mitochondrial transcripts. Positional cloning identified REME1 unambiguously as the gene controlling editing of nad2-558. Virus-induced gene silencing of REME1 confirmed its role in editing of nad2-558 and allowed us to identify orfX-552 as a second C whose editing is positively controlled by REME1. An unexpected outcome of REME1 silencing was the finding of a number of mitochondrial C targets whose editing extent exhibits a significant and reproducible increase in silenced tissues. That increase was shown to be partly due to the virus inoculation and partly to REME1-specific silencing. Analysis of an insertional T-DNA mutant within the REME1 coding sequence confirmed the findings of the virus-induced gene silencing experiments: decrease in editing extent of nad2-558 and orfX-552 and increase in editing extent of two sites, matR-1771 and rpl5-92. Transgenic complementation of the low-edited accession (Landsberg erecta) restored the editing of nad2-558 and orfX-552 to high-edited accession (Columbia)-type levels or to even higher levels than Columbia. There was no effect of the transgene on editing extent of matR-1771 and rpl5-92. The strategy and tools used in this report can be applied to identify additional genes that affect editing extent in plant mitochondria.