Regulation of transporter processes
Transporters are known to be regulated at the posttranslational level. This indicates that protein partners are interacting with the transporters to modify their activity. We use the glucosinolate defense compounds in the model plant Arabidopsis thaliana to study (re)mobilization of defense compounds from cellular storage in response to developmental and external cues.
Towards our goal of understanding the regulation of glucosinolate transporters (GTRs), we want to identify proteins that interact with the GTRs and modify their activity. We apply several independent approaches such as using the GTRs as baits in untargeted yeast-2-hybrid screens and in co-immunoprecipitation with tagged GTRs, as well as co-expression databases. Candidate interacting partners are characterized biochemically and the biological significance of their action investigated in vivo. Similar strategies will be applied with the additional glucosinolate transporters (both importers and exporters) currently being characterized.
Ultimately, this will advance our understanding of how regulation of transport processes across (sub)cellular barriers contribute to source and sink strength capacity and thereby to the distribution pattern of a given metabolite.
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Jørgensen ME, Olsen CE, Halkier BA, Nour-Eldin HH (2016) Phosphorylation at serine 52 and 635 does not alter the transport properties of glucosinolate transporter AtGTR1. Plant Signal Behav 11: e1071751. DOI:10.1080/15592324.2015.1071751
Jørgensen ME, Olsen CE, Geiger D, Mirza O, Halkier BA, Nour-Eldin HH (2015) A functional EXXEK motif is essential for proton coupling and active glucosinolate transport by NPF2.11. Plant Cell Physiol 56: 2340–2350. DOI:10.1093/pcp/pcv145