Laboratory of Functional Plant Biology, Department of Biology, Ghent University, B-9000 Gent, Belgium.
Molekulare Botanik, Universitaet Ulm, D-89069 Ulm, Germany.
Proc Natl Acad Sci U S A. 2017 Aug 15;114(33):8883-8888. doi: 10.1073/pnas.1705815114. Epub 2017 Jul 31.
Recent identification of several different types of RNA editing factors in plant organelles suggests complex RNA editosomes within which each factor has a different task. However, the precise protein interactions between the different editing factors are still poorly understood. In this paper, we show that the E-type pentatricopeptide repeat (PPR) protein SLO2, which lacks a C-terminal cytidine deaminase-like DYW domain, interacts in vivo with the DYW-type PPR protein DYW2 and the P-type PPR protein NUWA in mitochondria, and that the latter enhances the interaction of the former ones. These results may reflect a protein scaffold or complex stabilization role of NUWA between E-type PPR and DYW2 proteins. Interestingly, DYW2 and NUWA also interact in chloroplasts, and DYW2-GFP overexpressing lines show broad editing defects in both organelles, with predominant specificity for sites edited by E-type PPR proteins. The latter suggests a coordinated regulation of organellar multiple site editing through DYW2, which probably provides the deaminase activity to E editosomes.
最近在植物细胞器中鉴定出几种不同类型的 RNA 编辑因子，这表明在每个因子具有不同任务的复杂 RNA 编辑体中。然而，不同编辑因子之间的确切蛋白相互作用仍知之甚少。在本文中，我们表明，缺乏 C 端胞嘧啶脱氨酶样 DYW 结构域的 E 型五肽重复（PPR）蛋白 SLO2，在体内与 DYW 型 PPR 蛋白 DYW2 和 P 型 PPR 蛋白 NUWA 相互作用，并且后者增强了前者的相互作用。这些结果可能反映了 NUWA 在 E 型 PPR 和 DYW2 蛋白之间的蛋白支架或复合物稳定作用。有趣的是，DYW2 和 NUWA 也在叶绿体中相互作用，并且 DYW2-GFP 过表达系在两个细胞器中均表现出广泛的编辑缺陷，主要针对 E 型 PPR 蛋白编辑的位点具有特异性。后者表明通过 DYW2 对细胞器多部位编辑进行协调调节，这可能为 E 编辑体提供脱氨酶活性。
