The binding of auxin to the Arabidopsis auxin influxtransporter, AUX1
Carrier, David J. , Bakar, Norliza Tendot Abu , Swarup, Ranjan , Callaghan, Richard , Napier, Richard M. , Bennett, Malcolm J. and Kerr, Ian D. . (2008) The binding of auxin to the Arabidopsis auxin influxtransporter, AUX1. Plant Physiology, Vol.147 . ISSN 0032-0889Full text not available from this repository.
Official URL: http://dx.doi.org/10.1104/pp.108.122044
The cellular import of the hormone auxin is a fundamental requirement for the generation of auxin gradients which control a multitude of plant developmental processes. The AUX/LAX family of auxin importers, exemplified by AUX1 from Arabidopsis thaliana, has been shown to mediate auxin import when expressed heterologously. The quantitative nature of the interaction between AUX1 and its transport substrate indole-3-acetic acid (IAA) is incompletely understood and we sought to address this in the present investigation. We expressed AUX1 to high levels in a baculovirus expression system and prepared membrane fragments from baculovirus-infected insect cells. These membranes proved suitable for determination of the binding of IAA to AUX1 and enabled us to determine a Kd of 2.6 µM, comparable with estimates for the Km for IAA transport. The efficacy of a number of auxin analogues and auxin transport inhibitors to displace IAA binding from AUX1 has also been determined and can be rationalized in terms of their physiological effects. Determination of the parameters describing the initial interaction between a plant transporter and its hormone ligand provides novel quantitative data for modelling auxin fluxes.
|Item Type:||Journal Article|
|Subjects:||Q Science > QK Botany
Q Science > QH Natural history
|Divisions:||Faculty of Science > Life Sciences (2010- ) > Warwick HRI (2004-2010)|
|Library of Congress Subject Headings (LCSH):||Auxin|
|Journal or Publication Title:||Plant Physiology|
|Publisher:||American Society of Plant Biologists|
|Official Date:||9 July 2008|
|Access rights to Published version:||Open Access|
Version accepted by publisher (post-print, after peer review, before copy-editing).
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