BEX1/ARF1A1C is required for BFA-sensitive recycling of PIN auxin transporters and auxin-mediated development in arabidopsis Journal Article

Author(s): Tanaka, Hirokazu; Nodzyński, Tomasz; Kitakura, Saeko; Feraru, Mugurel I; Sasabe, Michiko; Ishikawa, Tomomi; Kleine-Vehn, Jürgen; Kakimoto, Tatsuo; Friml, Jiří
Article Title: BEX1/ARF1A1C is required for BFA-sensitive recycling of PIN auxin transporters and auxin-mediated development in arabidopsis
Affiliation IST Austria
Abstract: Correct positioning of membrane proteins is an essential process in eukaryotic organisms. The plant hormone auxin is distributed through intercellular transport and triggers various cellular responses. Auxin transporters of the PIN-FORMED (PIN) family localize asymmetrically at the plasma membrane (PM) and mediate the directional transport of auxin between cells. A fungal toxin, brefeldin A (BFA), inhibits a subset of guanine nucleotide exchange factors for ADP-ribosylation factor small GTPases (ARF GEFs) including GNOM, which plays a major role in localization of PIN1 predominantly to the basal side of the PM. The Arabidopsis genome encodes 19 ARF-related putative GTPases. However, ARF components involved in PIN1 localization have been genetically poorly defined. Using a fluorescence imaging-based forward genetic approach, we identified an Arabidopsis mutant, bfa-visualized exocytic trafficking defective1 (bex1), in which PM localization of PIN1-green fluorescent protein (GFP) as well as development is hypersensitive to BFA. We found that in bex1 a member of the ARF1 gene family, ARF1A1C, was mutated. ARF1A1C localizes to the trans-Golgi network/early endosome and Golgi apparatus, acts synergistically to BEN1/MIN7 ARF GEF and is important for PIN recycling to the PM. Consistent with the developmental importance of PIN proteins, functional interference with ARF1 resulted in an impaired auxin response gradient and various developmental defects including embryonic patterning defects and growth arrest. Our results show that ARF1A1C is essential for recycling of PIN auxin transporters and for various auxin-dependent developmental processes.
Keywords: Exocytosis; Auxin; Arabidopsis thaliana; PIN-FORMED; Embryogenesis
Journal Title: Plant and Cell Physiology
Volume: 55
Issue 4
ISSN: 1471-9053
Publisher: Oxford University Press  
Date Published: 2014-04-01
Start Page: 737
End Page: 749
Copyright Statement: CC-BY NC
DOI: 10.1093/pcp/pct196
Notes: This work was supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and the Japan Society for the Promotion of Science (JSPS) KAKENHI [23012026 and 23770147]; the International Human Frontier Science Program Organization (HFSP CDA) [to H.T.]; the Vienna Science and Technology Fund (WWTF) [to J.K.-V.]; the European Research Council [Independent Research grant ERC-2011-StG-20101109-PSDP to J.F.]; European Social Fund [CZ.1.07/2.3.00/20.0043 to J.F.]; the Czech Science Foundation GAČR [GA13-40637S to J.F.]; the state budget of the Czech Republic [project ‘Postdoc I.’ CZ.1.07/2.3.00/30.0009 to T.N.]. Part of the work was realized in the CEITEC – Central European Institute of Technology [CZ.1.05/1.1.00/02.0068].
Open access: no