Abstract
Proteins and lipids are delivered from the trans-Golgi network (TGN) to the cell exterior by secretory vesicles. However, little is known about the behavior of the vesicles. Secretory Carrier Membrane Protein (SCAMP) has four transmenbrane domains and various domains involved in the intracellular trafficking. We have been analyzing about the localization and the function of SCAMP in plant cells. Confocal laser scanning microscopy (CLSM) and TEM observation by high-pressure freezing technique revealed that SCAMP in tobacco BY-2 cells was localized in the plasma membrane (PM), TGN and novel vesicle cluster, designated SCAMP-containing vesicle cluster (SVC). By TEM, four-dimensional CLSM and total internal reflection microscopy, we showed that the SVC existed away from TGN. Moreover, we observed that the SVC fused with PM and cell plate. From these results, we conclude that the SVC is involved in the secretory pathway from the TGN to the cell exterior.
