This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 18/11/3171    most recent tpc.106.042770v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Kleine-Vehn, J. Articles by Friml, J. Search for Related Content PubMed PubMed Citation Articles by Kleine-Vehn, J. Articles by Friml, J. Agricola Articles by Kleine-Vehn, J. Articles by Friml, J.

Subcellular Trafficking of the Arabidopsis Auxin Influx Carrier AUX1 Uses a Novel Pathway Distinct from PIN1^[W]

Jürgen Kleine-Vehn^a, Pankaj Dhonukshe^a, Ranjan Swarup^b, Malcolm Bennett^b and Jií Friml^a,1

^a Center for Molecular Biology of Plants, University of Tübingen, D-72076 Tübingen, Germany
^b Plant Sciences Division, School of Biosciences, University of Nottingham, Loughborough LE12 5RD, United Kingdom

¹ To whom correspondence should be addressed. E-mail jiri.friml{at}zmbp.uni-tuebingen.de; fax 49-7071-295797.

The directional flow of the plant hormone auxin mediates multiple developmental processes, including patterning and tropisms. Apical and basal plasma membrane localization of AUXIN-RESISTANT1 (AUX1) and PIN-FORMED1 (PIN1) auxin transport components underpins the directionality of intercellular auxin flow in Arabidopsis thaliana roots. Here, we examined the mechanism of polar trafficking of AUX1. Real-time live cell analysis along with subcellular markers revealed that AUX1 resides at the apical plasma membrane of protophloem cells and at highly dynamic subpopulations of Golgi apparatus and endosomes in all cell types. Plasma membrane and intracellular pools of AUX1 are interconnected by actin-dependent constitutive trafficking, which is not sensitive to the vesicle trafficking inhibitor brefeldin A. AUX1 subcellular dynamics are not influenced by the auxin influx inhibitor NOA but are blocked by the auxin efflux inhibitors TIBA and PBA. Furthermore, auxin transport inhibitors and interference with the sterol composition of membranes disrupt polar AUX1 distribution at the plasma membrane. Compared with PIN1 trafficking, AUX1 dynamics display different sensitivities to trafficking inhibitors and are independent of the endosomal trafficking regulator ARF GEF GNOM. Hence, AUX1 uses a novel trafficking pathway in plants that is distinct from PIN trafficking, providing an additional mechanism for the fine regulation of auxin transport.

This article has been cited by other articles:

				L. Li, N. Saga, and K. Mikami Phosphatidylinositol 3-kinase activity and asymmetrical accumulation of F-actin are necessary for establishment of cell polarity in the early development of monospores from the marine red alga Porphyra yezoensis J. Exp. Bot., August 13, 2008; (2008) ern207v1. [Abstract] [Full Text] [PDF]

				E. Feraru and J. Friml PIN Polar Targeting Plant Physiology, August 1, 2008; 147(4): 1553 - 1559. [Full Text] [PDF]

				S. Robert, S. N. Chary, G. Drakakaki, S. Li, Z. Yang, N. V. Raikhel, and G. R. Hicks Endosidin1 defines a compartment involved in endocytosis of the brassinosteroid receptor BRI1 and the auxin transporters PIN2 and AUX1 PNAS, June 17, 2008; 105(24): 8464 - 8469. [Abstract] [Full Text] [PDF]

				R. G. Kulka Hormonal control of root development on epiphyllous plantlets of Bryophyllum (Kalanchoe) marnierianum: role of auxin and ethylene J. Exp. Bot., June 1, 2008; 59(9): 2361 - 2370. [Abstract] [Full Text] [PDF]

				P. Dhonukshe, I. Grigoriev, R. Fischer, M. Tominaga, D. G. Robinson, J. Hasek, T. Paciorek, J. Petrasek, D. Seifertova, R. Tejos, et al. Auxin transport inhibitors impair vesicle motility and actin cytoskeleton dynamics in diverse eukaryotes PNAS, March 18, 2008; 105(11): 4489 - 4494. [Abstract] [Full Text] [PDF]

				K. Hoyerova, L. Perry, P. Hand, M. Lankova, T. Kocabek, S. May, J. Kottova, J. Paces, R. Napier, and E. Zazimalova Functional Characterization of PaLAX1, a Putative Auxin Permease, in Heterologous Plant Systems Plant Physiology, March 1, 2008; 146(3): 1128 - 1141. [Abstract] [Full Text] [PDF]

				M. Cho, S. H. Lee, and H.-T. Cho P-Glycoprotein4 Displays Auxin Efflux Transporter-Like Action in Arabidopsis Root Hair Cells and Tobacco Cells PLANT CELL, December 1, 2007; 19(12): 3930 - 3943. [Abstract] [Full Text] [PDF]

				J. I. Kim, A. Sharkhuu, J. B. Jin, P. Li, J. C. Jeong, D. Baek, S. Y. Lee, J. J. Blakeslee, A. S. Murphy, H. J. Bohnert, et al. yucca6, a Dominant Mutation in Arabidopsis, Affects Auxin Accumulation and Auxin-Related Phenotypes Plant Physiology, November 1, 2007; 145(3): 722 - 735. [Abstract] [Full Text] [PDF]