Characterisation of the N-end rule pathway and its substrates as a modulator of the plant immune response

We previously provided the first evidence for functions for the N-end rule pathway of ubiquitin-mediated targeted proteolysis in plants (Gibbs et al Nature 2011; Gibbs et al Molecular Cell 2014; Abbas et al Current Biology 2015, Vicente et al Current Biology 2017). This pathway regulates the stability of regulatory proteins in eukaryotic cells, and is a key regulator of growth and development. The pathway controls protein degradation dependent on the amino (N)-terminal (Nt-) residue of proteins. We have shown that one branch of this pathway, controlled by a Glutamine Amido-hydrolase (NTAQ), controls the plant immune response. This is the first time that a function for this branch of the pathway has been discovered in plants. This project will focus on discovering protein substrates of NTAQ and understanding their contribution to plant defence responses. The student will learn molecular genetics of Arabidopsis thaliana, as well as developing theoretical and practical understanding of plant pathology. Molecular biology, proteomics and Western blotting will be used to validate mutants, analyse genetic stress markers and probe for new protein substrates. This study will reveal new functions for the N-end rule pathway, determining the relationship between newly discovered NTAQ substrates and the known plant immune network.