Auxin transport inhibitors impair vesicle motility and actin cytoskeleton dynamics in diverse eukaryotes

作者：Dhonukshe Pankaj; Grigoriev Ilya; Fischer Rainer; Tominaga Motoki; Robinson David G; Hasek Jiri; Paciorek Tomasz; Petrasek Jan; Seifertova Daniela; Tejos Ricardo; Meisel Lee A; Zazimalova Eva; Gadella Theodorus W J Jr; Stierhof York Dieter; Ueda Takashi; Oiwa Kazuhiro; Akhmanova Anna; Brock Roland; Spang Anne; Friml Jiri^*

来源：Proceedings of the National Academy of Sciences, 2008, 105(11): 4489-4494.

DOI：10.1073/pnas.0711414105

• PIN proteins
• plant development
• vesicle traffic
• auxin efflux inhibitors

Many aspects of plant development, including patterning and tropisms, are largely dependent on the asymmetric distribution of the plant signaling molecule auxin. Auxin transport inhibitors (ATIs), which interfere with directional auxin transport, have been essential tools in formulating this concept. However, despite the use of ATIs in plant research for many decades, the mechanism of ATI action has remained largely elusive. Using real-time live-cell microscopy, we show here that prominent ATIs such as 2,3,5-triiodobenzoic acid (TIBA) and 2-(1-pyrenoyl) benzoic acid (PBA) inhibit vesicle trafficking in plant, yeast, and mammalian cells. Effects on micropinocytosis, rab5-labeled endosomal motility at the periphery of HeLa cells and on fibroblast mobility indicate that ATIs influence actin cytoskeleton. Visualization of actin cytoskeleton dynamics in plants, yeast, and mammalian cells show that ATIs stabilize actin. Conversely, stabilizing actin by chemical or genetic means interferes with endocytosis, vesicle motility, auxin transport, and plant development, including auxin transport-dependent processes. Our results show that a class of ATIs act as actin stabilizers and advocate that actin-dependent trafficking of auxin transport components participates in the mechanism of auxin transport. These studies also provide an example of how the common eukaryotic process of actin-based vesicle motility can fulfill a plant-specific physiological role.

• 出版日期2008-3-18