3D Electron Tomography Study of Unconventional Exocytosis in Arabidopsis
Other conference paper


摘要Exocytosis is one of key mechanisms to deliver materials into extracellular space for cell function and communication. Conventional protein secretion (CPS) is achieved via an ER (endoplasmic reticulum)–Golgi-TGN (trans-Golgi network)–PM (plasma membrane) pathway in the plant endomembrane system. Unconventional protein secretion (UPS) bypassing the secretory organelles is also operated in plant cells, which shows a connection to plant defense and stress response. We have previously showed that 1) a double membrane organelle termed EXPO (exocyst-positive organelle) is distinct from the autophagosome; and 2) EXPO may mediate UPS via EXPO fusion with the plasma membrane (PM) for release of cytoplasmic contents outside of the cells upon the burst of the single membrane bounded vesicle. However, the presence of extracellular vesicles (EVs) or EXPO-like structures outside the PM remain to be demonstrated in intact plant cells, and the origin of these EVs/EXPO-like structures remains exclusive and controversial. In this study, we use 3D Tomography TEM (transmission electron microscope) to reconstruct Arabidopsis PM and extracellular space region to demonstrate how EVs/EXPO-like vesicles are secreted out. The obtained results so far indicate that 1) EVs/EXPO-like structures can be found in Arabidopsis root and pollen cells; 2) these EVs/EXPO-like structures vary in size and morphology; and 3) they are most likely secreted out by EXPO-PM fusion. Here we will present an update on this study. Supported by grants from the RGC and CUHK (G-CUHK402/15, CUHK14130716, CUHK2/CRF/11G, C4011-14R and AoE/M-05/12).
著者Hao YE, Yong CUI, Youshun LIN, Liwen JIANG
會議名稱20th European Network for Plant Endomembrane Research meeting

上次更新時間 2018-16-04 於 17:52