Our over-arching goal is to better understand the role of the ubiquitin modification system in plant biology using the model plant Arabidopsis thaliana. We seek to uncover the molecular mechanisms by which specific proteins are targetted for vacuolar or proteasomal degradation, and how the various stages of this pathway are regulated. This includes identifying the cis-acting signals that mediate the recognition of protein substrates by E3 ubiquitin ligases and discovering trans-acting factors that facilitate or impede substrate ubiquitination. Our lab focuses on three major projects.