Terada Kayo, Gimenez-Dejoz Joan, Kurita Taichi, Oikawa Kazusato, Uji Hirotaka, Tsuchiya Kousuke, Numata Keiji
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
ACS Biomater Sci Eng. 2021 Apr 12;7(4):1475-1484. doi: 10.1021/acsbiomaterials.0c01533. Epub 2021 Feb 19.
In the genetic modification of plant cells, the mitochondrion is an important target in addition to the nucleus and plastid. However, gene delivery into the mitochondria of plant cells has yet to be established by conventional methods, such as particle bombardment, because of the small size and high mobility of mitochondria. To develop an efficient mitochondria-targeting signal (MTS) that functions in plant cells, we designed the artificial peptide (LURL) and its analogues, which periodically feature hydrophobic α-aminoisobutyric acid (Aib, U) and cationic arginine (R), considering the consensus motif recognized by the mitochondrial import receptor Tom20. Circular dichroism measurements and molecular dynamics simulation studies revealed that (LURL) had a propensity to form a stable α-helix in 0.1 M phosphate buffer solution containing 1.0 wt % sodium dodecyl sulfate. After internalization into plant cells via particle bombardment, (LURL) revealed highly selective accumulation in the mitochondria, whereas its analogue (LARL) was predominantly located in the vacuoles in addition to mitochondria. The high selectivity of (LURL) can be attributed to the incorporation of Aib, which promotes the hydrophobic interaction between the MTS and Tom20 by increasing the hydrophobicity and helicity of (LURL). The present study provided a prospective mitochondrial targeting system using the simple design of artificial peptides.
在植物细胞的基因改造中，除细胞核和质体外，线粒体也是一个重要的靶点。然而，由于线粒体体积小且流动性高，通过传统方法（如粒子轰击）将基因导入植物细胞的线粒体尚未实现。为了开发一种在植物细胞中起作用的高效线粒体靶向信号（MTS），我们设计了人工肽（LURL）及其类似物，考虑到线粒体输入受体Tom20识别的共有基序，它们周期性地具有疏水的α-氨基异丁酸（Aib，U）和阳离子精氨酸（R）。圆二色性测量和分子动力学模拟研究表明，（LURL）在含有1.0 wt%十二烷基硫酸钠的0.1 M磷酸盐缓冲溶液中倾向于形成稳定的α-螺旋。通过粒子轰击内化到植物细胞后，（LURL）显示出在线粒体中的高度选择性积累，而其类似物（LARL）除了线粒体之外主要位于液泡中。（LURL）的高选择性可归因于Aib的掺入，它通过增加（LURL）的疏水性和螺旋度促进了MTS与Tom20之间的疏水相互作用。本研究提供了一种使用简单设计的人工肽的前瞻性线粒体靶向系统。
