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Subcellular trafficking of the Arabidopsis auxin influx carrier AUX1 uses a novel pathway distinct from PIN1.
- Source :
-
The Plant cell [Plant Cell] 2006 Nov; Vol. 18 (11), pp. 3171-81. Date of Electronic Publication: 2006 Nov 17. - Publication Year :
- 2006
-
Abstract
- 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.
- Subjects :
- Actins metabolism
Arabidopsis drug effects
Brefeldin A pharmacology
Cytoskeleton drug effects
Endosomes drug effects
Endosomes metabolism
Fluorescence Recovery After Photobleaching
Golgi Apparatus drug effects
Golgi Apparatus metabolism
Guanine Nucleotide Exchange Factors metabolism
Intracellular Membranes drug effects
Intracellular Membranes metabolism
Models, Biological
Phloem cytology
Phloem drug effects
Plant Epidermis cytology
Plant Epidermis drug effects
Protein Transport drug effects
Sterols metabolism
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Indoleacetic Acids metabolism
Membrane Transport Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1040-4651
- Volume :
- 18
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 17114355
- Full Text :
- https://doi.org/10.1105/tpc.106.042770