SEMINAR, 15.7.2015, Doan Luu
Where: B1-Library
Intracellular trafficking of aquaporins in Arabidopsis thaliana 
Aquaporins, channel proteins that facilitate water transport across the biological membranes of plant cells, have classically been used as reference markers for these membranes. Yet, recent studies have shown that the sub‐cellular localization of aquaporins is constantly adjusted in response to environmental stimuli. The present seminar addresses the mechanisms that determine the density at the cell surface of aquaporins of the Plasma Membrane Intrinsic Protein (PIP) subclass. Whereas pharmacological interference coupled to confocal imaging was extensively used in initial studies, single particle tracking of PIPs fused to GFP, fluorescence correlation spectroscopy and a novel fluorescence recovery after photobleaching approach have provided unique insights into the peculiarity of PIP cellular dynamics. It was shown in particular that, while endocytosis of PIPs is predominantly clathrin‐dependent under standard conditions, their cycling is enhanced under salt stress possibly involving a clathrin‐ and membrane raft‐mediated endocytosis. Future research will address the genetic bases of these pathways. To gain in details, super-resolution approaches were developed to study the localization and lateral diffusion of PIP at the cell surface.