Post-translational modifications by SUMO (Small Ubiquitin-like MOdifier) modulate protein activity through regulation of subcellular localization, protein activity and stability, and protein-protein interactions. In plants, SUMO is essential during seed development, modulates hormone signaling, and biotic/abiotic stress responses. Several studies point to a nuclear enrichment of SUMO conjugation machinery, which is consistent with a preferential nuclear localization of the SUMO targets. Nonetheless, non–nuclear targets exist and the molecular mechanisms that mediate their modification remain elusive. Dr Lois’s group has uncovered a novel regulatory mechanism consisting of the processing of the C-terminus of the SUMO E1-activating enzyme large subunit, SAE2. Processed SAE2 partially localize to the cytosol and the processing activity is prominent at the transition between embryo growth and seed maturation. Accumulation of SAE2 in the cytosol promotes cytosolic SUMOylation and behave as a signal for growth arrest, suggesting that SAE2 processing could contribute to finalising embryogenesis. SUMOCell aims to uncover the signals that trigger SAE2 cytosolic localization and the cellular responses activated by cytosolic SUMOylation. First, with Duke University partner, we will study SAE2 subcellular dynamics using super-resolution microscopy, under hormone treatments and stress challenges. Second, we will study the physiological processes regulated by SAE2 localization to the cytosol. For that, we will perform single-cell RNAseq studies from cells enriched in cytosolic SAE2. Bioinformatics analysis will be carried out by a placement at Sequentia SL. Finally, we will analyse physiological parameters related to seed quality. Data obtained from cell studies, transcriptomics and seed performance will be integrated in a signalling model to understand the role of cytosolic SUMO conjugation in seed development, providing a multidisciplinar training program.
Fields of science
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsproteomics
- natural sciencesphysical sciencesopticsmicroscopysuper resolution microscopy
- natural sciencesbiological sciencesdevelopmental biology
- medical and health sciencesclinical medicineembryology
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme