Functional interactomics of auxin transport
Molecular Plant Physiology - Hormone Transport
Work in our group is concentrating on the individual roles of auxin catalysts – members of ABCB/PGP- and PIN families - in auxin transport, their functional interaction and regulation and their impact on auxin-mediated plant physiology and plant development.
Although ABCB- and PIN-mediated auxin efflux can apparently function independently, ABCBs and PINs are able to interactively and coordinately transport auxin. The current model is that in interacting cells, multilaterally expressed ABCBs minimize apoplastic reflux while polar ABCB-PIN interactions provide the basis for specific, vectorial auxin streams.
Meanwhile, we have substantially characterized the FKBP42, TWISTED DWARF1 (TWD1), as a positive regulator of ABCB-catalyzed auxin transport by protein-protein interaction (Fig. 1). ABCB-TWD1 interaction and thus auxin flows are disrupted by binding of the diagnostic auxin efflux inhibitor, NPA, suggesting that ABCBs and TWD1 are key components of the NPA-sensitive auxin efflux complex.
Recent work has identified flavonols as endogenous modulators of auxin transport by inhibiting ABCBs and promoting asymmetric PIN shifts in the root (Fig. 2). Moreover, by means of chemical genomics, we have identified a novel ABCB-specific auxin transport inhibitor, called BUM.
Interactomics and cell biology of auxin transport complexes
Drug-modulation of transport complexes
Regulation of auxin catalystis by protein phosphorylation
Chemical genetic screens for natural and synthetic growth regulators
In silico analysis of transport complex functionality and interaction
Auxin transporter-cytoskeleton interaction
Hormone transport and action
Arabidopsis developmental biology
Transporter structure-function relationships