Journal Article

Endocytic and Secretory Traffic in Arabidopsis Merge in the Trans-Golgi Network/Early Endosome, an Independent and Highly Dynamic Organelle

van den Berg, Willy, Geldner, Niko, Stierhof, York-Dieter, Robinson, David G, Langhans, Markus, Jürgens, Gerd, Bubeck, Julia, de Vries, Sacco C, Krebs, Melanie, Viotti, Corrado, Schumacher, Karin, van Dongen, Walter, Takano, Junpei, Richter, Sandra

2010

Overview

Plants constantly adjust their repertoire of plasma membrane proteins that mediates transduction of environmental and developmental signals as well as transport of ions, nutrients, and hormones. The importance of regulated secretory and endocytic trafficking is becoming increasingly clear; however, our knowledge of the compartments and molecular machinery involved is still fragmentary. We used immunogold electron microscopy and confocal laser scanning microscopy to trace the route of cargo molecules, including the BRASSINOSTEROID INSENSITIVE1 receptor and the REQUIRES HIGH BORON1 boron exporter, throughout the plant endomembrane system. Our results provide evidence that both endocytic and secretory cargo pass through the trans-Golgi network/early endosome (TGN/EE) and demonstrate that cargo in late endosomes/multivesicular bodies is destined for vacuolar degradation. Moreover, using spinning disc microscopy, we show that TGN/EEs move independently and are only transiently associated with an individual Golgi stack.

• Publisher: American Society of Plant Biologists
• Subject: Antiporters / Antiporters - metabolism / Arabidopsis / Arabidopsis - metabolism / Arabidopsis Proteins / Arabidopsis Proteins - metabolism / atpase activity / blood proteins / Boron / boron transporter / brefeldin-a / by-2 cells / Cell walls / cell-wall pectins / confocal laser scanning microscopy / electron microscopy / Endocytosis / endoplasmic-reticulum / Endosomes / Freight / Golgi apparatus / homotypic fusion / Hormones / ion transport / metabolism / Microscopy, Confocal / Microscopy, Electron, Transmission / Multivesicular Bodies / Multivesicular Bodies - metabolism / nutrients / Plant cells / Plants / prevacuolar compartments / Protein Kinases / Protein Kinases - metabolism / Protein Transport / Receptors / root-cells / Seedlings / trans-Golgi Network / trans-Golgi Network - metabolism