B05: Protein interactions for the dynamic regulation of the IRON-REGULATED TRANSPORTER1 (IRT1) and cellular metal trafficking

IRON-REGULATED TRANSPORTER1 (IRT1) is the prominent member of an evolutionarily ancient family of divalent metal zinc and iron permeases (ZIP) and controls the entry of iron into roots of many plant species. IRT1 activity was found regulated at multiple levels, ranging from IRT1 gene expression to IRT1 protein stability and IRT1 trafficking and localization at the plasma membrane. The membrane-bound IRT1 protein contains a distinctive large cytosolic loop domain with discrete residues involved in protein stability control and metal binding. This cytosolic IRT1 loop domain was shown experimentally, also in our group, to confer protein-protein interactions in cells with different cytosolic and peripheral membrane-associated proteins. These interacting proteins may act at the face of membranes as molecular anchors to affect dynamic processes such as assembly of protein complexes for signaling, phospholipid composition, membrane fusion, vesicle formation and movement.

In this first round of CRC we will investigate IRT1 function and regulation and address links with iron signaling and intracellular iron homeostasis via the protein-protein interactions. Which roles do the IRT1 protein interactions play in regulation of iron uptake, intracellular IRT1 endomembrane trafficking and iron signaling from the plasma membrane to other compartments and targets? What is the nature of the iron-regulated mechanism that control IRT1 trafficking and function? To address these central questions, two doctoral researchers will specialize on complementary aspects related to either the biochemical or the cellular interactions between IRT1 and the cytosolic and peripheral membrane proteins. Genetic and physiological characterization will be combined with targeted interaction assays.

In the long term run of this CRC we expect to provide answers to the mechanistic and structural principles that regulate IRT1 and affect metal uptake and trafficking. This knowledge can be used to manipulate IRT1 activity and interactions for improved iron uptake and utilization in plants.

Project leader:
Prof. Dr. Petra Bauer, undefined email,
                         undefinedInstitute of Botany

Researchers: Imran Khan, undefined email
                        Inga Mohr, undefined email
                        Karolin Mo
ntag, undefined email
                        Dr. Rumen Ivanov, undefined email

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