PhD fellowship in Grenoble

Intrinsically Disordered Proteins and Temperature Sensing – Structural Studies of ELF3

Due to climate change and global warming, understanding how plants sense and respond to changes in temperature is a critical challenge for ensuring crop yield and food security in the coming decades. Recent studies suggest that the plant-specific protein, EARLY FLOWERING 3 (ELF3), acts as a direct thermosensor. ELF3 is an intrinsically disordered protein (IDP) with a low-complexity prion-like domain (PrLD) containing a glutamine-rich polyQ region. Tandem repeats of polyQs are represented in a large proportion of eukaryotic proteins involved in complex formation and transcriptional regulation. Expansion of polyQ tracts above a certain threshold (36Q) is responsible for neurodegenerative diseases including Huntington disease and ataxias in humans. However, shorter non-pathogenic polyQ tracts likely play important roles in genetic variation and adaptation in diverse organisms, although their mechanism of action is much less well-studied. Arabidopsis offers an attractive model to investigate the putative role of the ELF3 polyQ PrLD due to the wide geographic distribution of the plant and the availability of hundreds of sequenced genomes. Recent data suggests that the PrLD domain of ELF3 allows it to act as a thermosensor by switching the protein from a monomeric to aggregated species in a temperature-dependent manner. The proposed thesis project will define the molecular mechanism of ELF3-mediated thermosensing through biochemical, biophysical and structural experiments. The project has 3 main objectives: 1) produce and characterize ELF3 full length and PrLD constructs, 2) characterise the protein using biophysical techniques including SEC-MALS and CD 3) characterize the structure and dynamics at different temperatures by high resolution solution state NMR (600, 700, 850 and 950 MHz spectrometers at the IBS). These objectives will allow us to develop a molecular understanding of how ELF3 is able to respond to temperature changes over a narrow growth permissive range. In the longer term these data will form the basis of engineering altered thermoresponse through targeted mutations in ELF3 in model plant and crop species for improved adaptation to warming growth conditions.

This 3-year thesis project is funded through the Initiatives de Recherche Stratégiques (IRS) IDEX Université Grenoble-Alpes. Start date Sept-Nov 2018.

For more information or to submit your CV and letter of motivation please contact: C. ZUBIETA (CEA/PCV/BIG) chloe.zubieta@cea.fr and M. BLACKLEDGE (IBS) martin.blackledge@ibs.fr