Dynamic Behavior of the trans-Golgi Network in Root Tissues of Arabidopsis Revealed by Super-Resolution Live Imaging
Dynamic Behavior of the trans-Golgi Network in Root Tissues of Arabidopsis Revealed by Super-Resolution Live Imaging
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DOI：
10.1093/pcp/pcu010
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发表时间：
2014-04-01
影响因子：
4.9
通讯作者：
Nakano, Akihiko
中科院分区：
文献类型：
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作者：
Uemura, Tomohiro;Suda, Yasuyuki;Nakano, Akihiko
反式高尔基体网络（trans-Golgi network，TGN）是高尔基体后网络中蛋白质转运的重要细胞器，其功能是将货物蛋白引导至各种目的地，包括高尔基体后区室和细胞外空间。然而，TGN在植物细胞中的功能和动力学尚未得到很好的理解。为了阐明植物TGN的动力学，我们建立了表达绿色荧光蛋白（GFP）-SYP 43的转基因植物，SYP 43是Tlg 2/syntaxin 16的直系同源物，其在作为TGN标记的天然启动子的控制下定位于酵母和哺乳动物细胞中的TGN。通过激光共聚焦显微镜和超分辨激光共聚焦活体成像显微镜观察，发现拟南芥根中存在两种类型的TGN：位于高尔基体反侧的GA-TGNs（Golgi-associated TGNs）和远离高尔基体独立活动的GI-TGNs（Golgi-released independent TGNs）。GI-TGN通过分离衍生自GA-TGN的群体，尽管GA-TGN的核心甚至在GI-TGN产生之后仍然存在。我们进一步发现，GI-TGN的丰度在所观察的组织之间不同。我们的研究结果表明，在植物细胞中的TGN的动力学特征不同于动物和酵母细胞。
The trans-Golgi network (TGN) is an important organelle for protein transport at the post-Golgi network, which functions as a sorting station that directs cargo proteins to a variety of destinations including post-Golgi compartments and the extracellular space. However, the functions and dynamics of the TGN in plant cells have not been well understood yet. To elucidate the dynamics of the plant TGN, we established transgenic plants expressing green fluorescent protein (GFP)-SYP43, the ortholog of Tlg2/syntaxin16, which is localized to the TGN in yeast and mammalian cells, under the control of the native promoter as a TGN marker. Observation by confocal laser scanning microscopy and super-resolution confocal live imaging microscopy revealed two types of TGN in Arabidopsis root: the GA-TGNs (Golgi-associated TGNs), located on the trans-side of the Golgi apparatus, and the GI-TGNs (Golgi-released independent TGNs), located away from the Golgi apparatus and behaving independently. The GI-TGNs is derived from a population of GA-TGNs by segregation, although the core of the GA-TGN remains even after the generation of the GI-TGN. We further found that the abundance of the GI-TGNs differs between observed tissues. Our results indicate that the dynamic features of the TGN in plant cells differ from those of animal and yeast cells.