A Combinatorial Reporter Set to Visualize the Membrane Contact Sites Between Endoplasmic Reticulum and Other Organelles in Plant Cell
A Combinatorial Reporter Set to Visualize the Membrane Contact Sites Between Endoplasmic Reticulum and Other Organelles in Plant Cell
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组合报告基因组可可视化植物细胞内质网和其他细胞器之间的膜接触位点
DOI：
10.3389/fpls.2020.01280
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发表时间：
2020-08-18
影响因子：
5.6
通讯作者：
Gao, Caiji
中科院分区：
文献类型：
--
作者：
Li, Tingting;Xiao, Zhidan;Gao, Caiji
膜接触位点（MCS）通过在延伸的膜表面上以数十纳米的距离关联细胞器来实现细胞器间的通信，并通过细胞器之间的代谢物、脂质和钙的有效交换、细胞器分裂和运动来维持细胞内稳态。大多数MCSs和越来越多的栓系蛋白，特别是那些参与介导内质网（ER）和其他细胞器之间的连接已被广泛的哺乳动物和酵母的特点。然而，对植物MCSs的研究仍处于起步阶段，至少一个原因可能是由于缺乏真正的标记物来可视化植物细胞中的这些膜连接。本研究设计了一系列基于GFP蛋白的报告基因，用于检测植物细胞内质网与叶绿体、线粒体和质膜之间可能存在的MCSs。通过在烟草原生质体和烟草叶片中表达这些基因编码的报告基因，我们可以直观地观察到ER-叶绿体MCS报告基因表达时叶绿体周围的点状信号、ER-线粒体MCS报告基因表达时的点状信号以及ER-PM MCS报告基因表达时PM附近的点状信号。我们还表明，ER-叶绿体MCSs的动态结构，进行积极的重塑与伴随发生的叶绿体功能障碍的植物细胞内。这项研究表明，ER与植物细胞中的各种细胞器密切相关，并提供了可能适用于可视化植物MCSs的工具。
The membrane contact sites (MCSs) enable interorganelle communication by associating organelles at distances of tens of nanometers over extended membrane surfaces and serve to maintain cellular homeostasis through efficient exchange of metabolites, lipid, and calcium between organelles, organelle fission, and movement. Most MCSs and a growing number of tethering proteins especially those involved in mediating the junctions between endoplasmic reticulum (ER) and other organelles have been extensively characterized in mammal and yeast. However, the studies of plant MCSs are still at stages of infancy, at least one reason might be due to the lack of bona fide markers for visualizing these membrane junctions in plant cells. In this study, a series of genetically encoded reporters using split super-folder GFP protein were designed to detect the possible MCSs between ER and three other cellular compartments including chloroplast, mitochondria and plasma membrane (PM) in plant cell. By expressing these genetically encoded reporter inArabidopsisprotoplasts as well asNicotiana benthamianaleaf, we could intuitively observe the punctate signal surrounding chloroplast upon expression of ER-chloroplast MCS reporter, punctate signal of ER-mitochondria MCS reporter and punctate signal close to the PM upon expression of ER-PM MCS reporter. We also showed that the ER-chloroplast MCSs were dynamic structures that undergo active remodeling with concomitant occurrence of chloroplast dysfunction inside plant cells. This study demonstrates that ER associates with various organelles in close proximity in plant cells and provides tools that might be applicable for visualizing MCSs in plants.