Trujillo LabCopyright: © Marco Trujillo
At the Institute of Molecular Plant Physiology we investigate how plants are able to cope with stresses. Plants are able to sense environmental cues and respond to them rapidly in order to efficiently acclimate. Responses to challenges occur at multiple levels, and coordinated proteolysis is paramount to allow plants to reshape the proteome, as well as to maintain protein homeostasis (proteostasis) during cellular stress. We take a multidisciplinary approach to understand how the signalling molecule ubiquitin shapes cellular responses to stress.
We believe that understanding the basic mechanisms by which plants are able to survive challenging environments, will provide the basis for the development of solutions to enable sustainable agriculture in the face of climate change.
Our research areas
Mechanisms of ubiquitinationCopyright: © Marco Trujillo
Even though ubiquitination participates in most, if not all cellular processes, many questions in the field remain unanswered. These include questions regarding the basis of the ubiquitination process. The final step is carried out by the ubiquitin ligase (E3) which guides the modification of a substrate by bringing both the E2-ubiquitin conjugate and the substrate together. One of the outstanding questions concerns the regulation of the E3 ligase activity, in particular of single-unit E3 ligases of which there are more than 540 in Arabidopsis.
Regulatory functions of ubiquitin
Ubiquitin signalling plays a key role in the regulation of cellular responses. Our aim is to uncover cellular processes and the components that are targeted by ubiquitination, with a focus on the immune response (Trujillo 2021). Ubiquitin and ubiquitin-like protein modifiers play key roles in controlling signalling amplitude and intensity, as well as in buffering proteome imbalances caused by pathogen attack. An intertwined and complex signalling circuitry, regulates cellular dynamics and protein degradation to maintain homeostasis.
One of the ultimate aims is to engineer systems allowing Targeted Protein Degradation (TPD). However, the study of ubiquitinated proteins faces many challenges such as the low stoichiometry of ubiquitin, rapid cleavage of ubiquitin moieties and the degradation of modified proteins. By reconstituting the ubiquitination cascade in an orthogonal system such as E. coli, we are able to circumvents some of these limitations.