Cellular and molecular requirements for polar PIN targeting and transcytosis in plants Journal Article

Author(s): Kleine-Vehn, Jürgen; Łangowski, Łukasz; Wiśniewska, Justyna; Dhonukshe, Pankaj; Brewer, Philip B; Friml, Jiří
Article Title: Cellular and molecular requirements for polar PIN targeting and transcytosis in plants
Abstract: The polar, sub-cellular localization of PIN auxin efflux carriers determines the direction of intercellular auxin flow, thus defining the spatial aspect of auxin signalling. Dynamic, transcytosis-like relocalizations of PIN proteins occur in response to external and internal signals, integrating these signals into changes in auxin distribution. Here, we examine the cellular and molecular mechanisms of polar PIN delivery and transcytosis. The mechanisms of the ARF-GEF-dependent polar targeting and transcytosis are well conserved and show little variations among diverse Arabidopsis ecotypes consistent with their fundamental importance in regulating plant development. At the cellular level, we refine previous findings on the role of the actin cytoskeleton in apical and basal PIN targeting, and identify a previously unknown role for microtubules, specifically in basal targeting. PIN protein delivery to different sides of the cell is mediated by ARF-dependent trafficking with a previously unknown complex level of distinct ARF-GEF vesicle trafficking regulators. Our data suggest that alternative recruitment of PIN proteins by these distinct pathways can account for cell type- and cargo-specific aspects of polar targeting, as well as for polarity changes in response to different signals. The resulting dynamic PIN positioning to different sides of cells defines a three-dimensional pattern of auxin fluxes within plant tissues.
Keywords: Cytoskeleton; Polarity; Protein targeting
Journal Title: Molecular Plant
Volume: 1
Issue 6
ISSN: 1752-9867
Publisher: Oxford University Press  
Date Published: 2008-01-01
Start Page: 1056
End Page: 1066
DOI: 10.1093/mp/ssn062
Open access: no