Periodic Reporting for period 1 - CHLARABIDOX (Discovering genome-wide thiol-dependent metabolic regulation in photosynthesis with redox chemoproteomics)
Reporting period: 2020-06-01 to 2022-05-31
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). Photosynthesis is an essential process for life on Earth. In recent years, increased atmospheric CO2 is causing concern and its reduction 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 this context, algae are diverse aquatic photosynthetic organisms found all over the planet and closely related to plants. Chlamydomonas reinhardtii is a single-cell alga that has been used as a model organism for decades. In the laboratory, we expose Chlamydomonas cultures to conditions that mimic a day in nature to generate exceptionally well synchronized cultures, that allow us to investigate all the essential processes required for the life of this alga. In our project, we are particularly interested in studying modifications of proteins that change their conformations and activities in response to internal or external stimuli that have an impact on the operation of the photosynthetic apparatus over the diurnal cycle. Our focus is a type of modification that changes the oxidation state of the protein. The findings of our research might have applications in the biofuels space or the production of high value bioproducts.
The goal of this project is to identify functional and redox-sensitive cysteine residues whose status changes during the diurnal cycle at a proteome-wide level in Chlamydomonas through the diurnal period. To achieve this goal, we have combined two different redox proteomics approaches in collaboration with different laboratories from the US: isoTOP-ABPP approach and thiol resin-assisted enrichment method. We successfully validated both approaches to monitor disulphide-dithiol status of the whole proteome throughout the diurnal cycle of Chlamydomonas. In parallel, we have also characterized the Chlamydomonas diurnal cycle at different light intensities (low light, medium light and high light).
The outcome of the project will be a proteome-wide view of the operation of regulatory redox sensors, which informs 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.