The system requires activity of three enzymes (E1, E2 and E3) to bind covalently a small peptide called ubiquitin (Ub) to proteins to be degraded by the 26S proteasome. The ubiquitin E3 ligases play an important role because they are responsible to recognize the substrates. Plants use UPS to control important switches during growth and development, hormone signalling, circadian rhythm, abiotic and biotic stress responses.
We have selected the protein group of RING type ubiquitin E3 ligases as targets to assign them in plant developmental stages and organs by high throughput phenotyping of plant responses upon mutation and by structure-functional biochemical characterization.