Lee Dong Wook, Lee Sumin, Min Chan-Ki, Park Cana, Kim Jeong-Mok, Hwang Cheol-Sang, Park Sang Ki, Cho Nam-Hyuk, Hwang Inhwan
Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, South Korea.
Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea.
Front Plant Sci. 2020 Feb 13;11:64. doi: 10.3389/fpls.2020.00064. eCollection 2020.
Plants have two endosymbiotic organelles, chloroplast and mitochondrion. Although they have their own genomes, proteome assembly in these organelles depends on the import of proteins encoded by the nuclear genome. Previously, we elucidated the general design principles of chloroplast and mitochondrial targeting signals, transit peptide, and presequence, respectively, which are highly diverse in primary structure. Both targeting signals are composed of N-terminal specificity domain and C-terminal translocation domain. Especially, the N-terminal specificity domain of mitochondrial presequences contains multiple arginine residues and hydrophobic sequence motif. In this study we investigated whether the design principles of plant mitochondrial presequences can be applied to those in other eukaryotic species. We provide evidence that both presequences and import mechanisms are remarkably conserved throughout the species. In addition, we present evidence that the N-terminal specificity domain of presequence might have evolved from the bacterial TAT (twin-arginine translocation) signal sequence.
植物有两种内共生细胞器，即叶绿体和线粒体。尽管它们有自己的基因组，但这些细胞器中的蛋白质组组装依赖于核基因组编码的蛋白质的导入。此前，我们分别阐明了叶绿体和线粒体靶向信号、转运肽和前导序列的一般设计原则，它们在一级结构上高度多样。这两种靶向信号均由N端特异性结构域和C端转运结构域组成。特别是，线粒体前导序列的N端特异性结构域包含多个精氨酸残基和疏水序列基序。在本研究中，我们调查了植物线粒体前导序列的设计原则是否可应用于其他真核生物物种。我们提供的证据表明，前导序列和导入机制在整个物种中都非常保守。此外，我们还提供证据表明，前导序列的N端特异性结构域可能是从细菌的双精氨酸转运（TAT）信号序列进化而来的。
