| Institution: | 1. Department of Bioscience and Biotechnology, Graduate School of Bioenvironmental Sciences, Kyushu University , Fukuoka, Japan;2. Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University , Fukuoka, Japan;3. RIKEN Plant Science Center , Yokohama, Japan |
| Abstract: | ABSTRACT Endomembrane transport system begins at the endoplasmic reticulum (ER), continues to the Golgi apparatus and subsequent compartment called trans-Golgi network (TGN). We found that SUT2, a tobacco sucrose-transporter ortholog and was localized in the TGN, decreased significantly under a sucrose-starvation condition. The tobacco SNARE protein SYP41, localized in the TGN and secretory vesicle cluster (SVC), also decreased under the starvation. Similarly, the SCAMP2-RFP fusion protein, which is localized in TGN, SVC, and plasma membrane (PM), was distributed solely in the PM under the starvation. Under the same starvation condition, protein secretion was not arrested but pectin deposition to cell wall was suppressed. These data indicated that the protein composition in TGN and existence of the SVC are regulated by sugar availability. Furthermore, our findings as well as the involvement of SVC in pectin secretion suggested that synthesis and transport of pectin are regulated by the level of extracellular sugars. |
