The Diurnal Redox Proteome of Chlamydomonas
EMSL Project ID
51353
Abstract
Nearly all organisms exhibit diurnal metabolic cycles, especially phototrophs, whose metabolism is strictly dependent on light. Transcriptomics experiments in cyanobacteria, algae and plants have indicated that good fractions of the genome are regulated periodically in a diurnal pattern. In previous work, we used light and temperature regimes to generate exceptionally well synchronized Chlamydomonas cultures that divide exactly once every 24h. Thus, by dense temporal sampling (by 2h in a 24h cycle) we recorded growth, timing of division, metabolic capacity (photosynthesis, respiration, fermentation), key metabolites (including PQ/PQH2), transcript abundances derived from all 3 genomes (nuclear, mitochondrial and plastidial), and quantitative proteomics. It was concluded that nearly the entire genome (90% of transcribed genes) is differentially expressed with different sets of transcripts being sequentially up- and down-regulated over the course of the day. That reflects the temporal segregation of various metabolic pathways as a cell progresses through its life cycle. We want to take this work to the next level, and we have one major objective: to monitor the redox proteome of the Chlamydomonas cell during synchronized cell division to parallel measurements of the proteome, transcriptome and bioenergetics physiology. For this purpose, we will investigate i) the modifications of the proteome during metabolic cycles, especially changes in thiol status of chloroplast proteins, which reflects the operation of regulatory redox sensors and ii) protein carbonylation, which reflects oxidative damage. The project will yield an unprecedented (in terms of associated metadata and other measurements) wealth of data, which will inform the development of models of macromolecular and small molecule metabolism in a flagship organism for the DOE. This work advances the use of systems biology approaches for developing a predictive understanding of biological, environmental and energy systems, which is a pre-requisite for finding solutions to energy and environmental challenges. The EMSL user program is ideally suited for the project because of the strong tradition of quantitative proteomics at PNNL, the large number of samples, which will leverage other high throughput and quantitative omics data types, and the new method development (for carbonylation), and for exploiting previously developed methods at EMSL (thiol status).
Project Details
Project type
Large-Scale EMSL Research
Start Date
2020-10-01
End Date
2022-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
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