Direct evaluation of metabolic rhythms from quantitative circadian proteomics revealed rampant post-transcriptional regulation by Chlamydomonas clock

ABSTRACT: Temporal dynamics in an organism's behavior, physiology, metabolism, and biochemistry over the course of 24 hours are governed by an inherent cellular clock. Transcriptomic studies revealed that the clock is governed by intricate transcriptional and translational feedback loops(TTFLs) involving daily transcription and translation of the clock genes. As a result, the consensus focussed on transcription as the primary driver of this daily regulation since mRNA of the clock genes show robust oscillations. However, protein dynamics across the 24-hour cycle have not been studied in great detail. The notion of mRNA rhythms corresponding to protein rhythms needs reinvestigation. Many recent studies revealed that the pattern of mRNA rhythms does not match their encoded protein rhythms. Here, we used a high-throughput quantitative mass spectrometry technique to investigate the daily variation in protein expression in a single-cell phytoplankton C.reinhardtii. We found hundreds of proteins oscillating over 24 hours. Further, we found several known and unique physiological and metabolic pathways are controlled by the circadian clock in a time-dependent manner. In addition, to gain more insights into the complex clock regulation of these pathways, we compared the RNA abundance to protein abundance. Intriguingly, we found a significant discrepancy in the peak phase distribution of RNA and proteins unraveling the intricate mechanism shaping the daily circadian physiology and metabolism in C.reinhardtii. Altogether, our study reports the first comprehensive circadian proteome and the important role of post-transcriptional control over the C.reinhardtii circadian clock.

INSTRUMENT(S): TripleTOF 6600

ORGANISM(S): Chlamydomonas Reinhardtii

TISSUE(S): Photosynthetic Cell

SUBMITTER: Dinesh Jadhav  

LAB HEAD: Sougata Roy

PROVIDER: PXD043839 | Pride | 2025-05-27

REPOSITORIES: pride