RABA Members Act in Distinct Steps of Subcellular Trafficking of the FLAGELLIN SENSING2 Receptor

• Published in: The Plant cell 2013-03, Vol.25 (3), p.1174-1187
• Main Authors: Choi, Seung-won, Tamaki, Takayuki, Ebine, Kazuo, Uemura, Tomohiro, Ueda, Takashi, Nakano, Akihiko
• Format: Article
• Language: English
• Subjects: Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cell Membrane - genetics; Cell Membrane - metabolism; Cell membranes; Endocytosis; Endosomes; Endosomes - genetics; Endosomes - metabolism; Epidermal cells; Genetic Vectors - genetics; Genetic Vectors - metabolism; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Ligands; Nicotiana - genetics; Nicotiana - metabolism; Organelles; Perceptual localization; Physiological regulation; Plant cells; Plant Epidermis - genetics; Plant Epidermis - metabolism; Plant Leaves - genetics; Plant Leaves - metabolism; Plasmids - genetics; Plasmids - metabolism; Protein Kinases - genetics; Protein Kinases - metabolism; Protein Transport; Qa-SNARE Proteins - genetics; Qa-SNARE Proteins - metabolism; Quantitative analysis; rab GTP-Binding Proteins - genetics; rab GTP-Binding Proteins - metabolism; Receptors; trans-Golgi Network - genetics; trans-Golgi Network - metabolism; Vacuolar Proton-Translocating ATPases - genetics; Vacuolar Proton-Translocating ATPases - metabolism
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.112.108803

Cell surface proteins play critical roles in the perception of environmental stimuli at the plasma membrane (PM) and ensuing signal transduction. Intracellular localization of such proteins must be strictly regulated, which requires elaborate integration of exocytic and endocytic trafficking pathways. Subcellular localization of Arabidopsis thaliana FLAGELLIN SENSING2 (FLS2), a receptor that recognizes bacterial flagellin, also depends on membrane trafficking. However, our understanding about the mechanisms involved is still limited. In this study, we visualized ligand-induced endocytosis of FLS2 using green fluorescent protein (GFP)-tagged FLS2 expressed in Nicotiana benthamiana. Upon treatment with the flg22 peptide, internalized FLS2-GFP from the PM was transported to a compartment with properties intermediate between the trans-Golgi network (TGN) and the multivesicular endosome. This compartment gradually discarded the TGN characteristics as it continued along the trafficking pathway. We further found that FLS2 endocytosis involves distinct RABA/RAB11 subgroups at different steps. Moreover, we demonstrated that transport of de novo—synthesized FLS2 to the PM also involves a distinct RABA/RAB11 subgroup. Our results demonstrate the complex regulatory system for property localizing FLS2 and functional differentiation in RABA members in endoand exocytosis.