Periodic Reporting for period 2 - CHLARABIDOX (Discovering genome-wide thiol-dependent metabolic regulation in photosynthesis with redox chemoproteomics)
Berichtszeitraum: 2022-06-01 bis 2023-05-31
Photosynthesis is a biological process that converts sunlight (renewable energy) and carbon dioxide (an important greenhouse gas) into oxygen (used to breathe) and organic matter (nutrients). Thus, photosynthesis not only is an essential process for life on Earth, due to increasing concern on global warming caused by atmospheric CO2 accumulation, it is also a process that allows tools for reducing atmospheric CO2, which is one of the Sustainable Development Goals (13. Climate Action). In this regard, research interest on photosynthetic organisms is gaining even more attention with the aim of providing tools for facing the challenge of global warming. In our project we have used two photosynthetic model organisms: Chlamydomonas reinhardtii, a single-cell alga, and Arabidopsis thaliana, a land plant. We aim to study modifications of proteins that change their conformations and activities in response to internal or external stimuli, such as light, that have an impact on the operation of the photosynthetic apparatus. Our focus is a type of modification that changes the oxidation state of the protein. The findings of our research might have applications for the field of plant science: i) in the case of algae, by developing new biotechnological strategies to manipulate their metabolism for production of biofuels and bioproducts, and ii) in the case of plants, by generating new useful tools to develop innovative strategies of crop acclimation to future climate conditions, given that the climatic change is expected to have an enormous impact on agronomic yields worldwide.
The goal of this project is to identify functional and redox-sensitive cysteine residues at a proteome-wide level relevant through the Chlamydomonas reinhardtii cell cycle and for plant (Arabidopsis thaliana) response to changes in light intensity. To achieve this goal, we have combined two different redox proteomics approaches in collaboration with different laboratories in the USA: isoTOP-ABPP approach and thiol resin-assisted enrichment method. We have successfully validated both approaches to monitor disulphide-dithiol status of the entire proteome during the diurnal cycle of Chlamydomonas. In parallel, we have also characterized the Chlamydomonas diurnal cycle under different light intensities (low, medium, and high). To generate the redox proteome of Arabidopsis, we used the thiol resin-assisted enrichment approach. An inventory of the key redox-regulated enzymes in both photosynthetic organisms is expected to be published soon. In the meantime, the results of the project have already been disseminated in local, national, and international conferences, in addition to outreach activities.
The outcome of the project will be a proteome-wide view of the operation of regulatory redox sensors in photosynthetic organisms, which will inform the development of light-driven metabolic models. Moreover, in combination with the physiological characterization, transcriptome, and proteome of Chlamydomonas during the diurnal period at different light intensities, our results will be a rich resource for metabolic models in plant field.