Dynamics of lipids and metabolites during the cell cycle of <i>Chlamydomonas reinhardtii</i>

Jüppner, Jessica; Mubeen, Umarah; Leisse, Andrea; Brust, Henrike; Steup, Martin; Herrmann, Markus; Steinhauser, Dirk; Giavalisco, Patrick

doi:10.1111/tpj.13642

Cited by 44 publications

(68 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Lipids of Chlamydomonas are observed to show specific alterations in relation to the phase in the cell cycle; and three unique patterns can be seen (Juppner et al ., ). TAGs have shown a bimodal accumulation, with degradation occurring in the middle of the day, as well as at the beginning of the night.…”

Section: Lipid Degradation In Relation To Other Cellular Processesmentioning

confidence: 97%

Lipid catabolism in microalgae

et al. 2018

View full text Add to dashboard Cite

Lipid degradation processes are important in microalgae because survival and growth of microalgal cells under fluctuating environmental conditions require permanent remodeling or turnover of membrane lipids as well as rapid mobilization of storage lipids. Lipid catabolism comprises two major spatially and temporarily separated steps, namely lipolysis, which releases fatty acids and head groups and is catalyzed by lipases at membranes or lipid droplets, and degradation of fatty acids to acetyl-CoA, which occurs in peroxisomes through the β-oxidation pathway in green microalgae, and can sometimes occur in mitochondria in some other algal species. Here we review the current knowledge on the enzymes and regulatory proteins involved in lipolysis and peroxisomal β-oxidation and highlight gaps in our understanding of lipid degradation pathways in microalgae. Metabolic use of acetyl-CoA products via glyoxylate cycle and gluconeogenesis is also reviewed. We then present the implication of various cellular processes such as vesicle trafficking, cell cycle and autophagy on lipid turnover. Finally, physiological roles and the manipulation of lipid catabolism for biotechnological applications in microalgae are discussed.

show abstract

Section: Lipid Degradation In Relation To Other Cellular Processesmentioning

confidence: 97%

Lipid catabolism in microalgae

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In the present study, we therefore conducted a systemic study to better understand the physiological and molecular response of Chlamydomonas to pharmacological‐induced TOR inhibition. Contrary to all the previous studies, we analyze the influence of rapamycin treatment on cell cycle dynamics, primary‐ and lipid metabolism, using synchronized cultures, grown under photoautotrophic conditions (Juppner et al ., ). In addition to using self‐sustaining growth conditions, we also included short‐term kinetic sampling throughout the complete diel cell cycle, allowing us to determine the timing and chronology of physiological and molecular changes after TOR repression.…”

Section: Introductionmentioning

confidence: 97%

The target of rapamycin kinase affects biomass accumulation and cell cycle progression by altering carbon/nitrogen balance in synchronized Chlamydomonas reinhardtii cells

et al. 2017

Self Cite

View full text Add to dashboard Cite

SUMMARYSeveral metabolic processes tightly regulate growth and biomass accumulation. A highly conserved protein complex containing the target of rapamycin (TOR) kinase is known to integrate intra-and extracellular stimuli controlling nutrient allocation and hence cellular growth. Although several functions of TOR have been described in various heterotrophic eukaryotes, our understanding lags far behind in photosynthetic organisms. In the present investigation, we used the model alga Chlamydomonas reinhardtii to conduct a time-resolved analysis of molecular and physiological features throughout the diurnal cycle after TOR inhibition. Detailed examination of the cell cycle phases revealed that growth is not only repressed by 50%, but also that significant, non-linear delays in the progression can be observed. By using metabolomics analysis, we elucidated that the growth repression was mainly driven by differential carbon partitioning between anabolic and catabolic processes. Accordingly, the time-resolved analysis illustrated that metabolic processes including amino acid-, starch-and triacylglycerol synthesis, as well RNA degradation, were redirected within minutes of TOR inhibition. Here especially the high accumulation of nitrogen-containing compounds indicated that an active TOR kinase controls the carbon to nitrogen balance of the cell, which is responsible for biomass accumulation, growth and cell cycle progression.

show abstract

“…Starch would be consumed for the cell division process in the dark and also in light, when energy could be provided directly by photosynthesis (Wanka, ; Vítová et al ., ). In a recent study of cell cycle of C. reinhardtii primary metabolites and lipids were followed throughout the diurnal cell cycle (Jüppner et al ., ). The authors showed that protein, DNA, and starch synthesis took place during light whereas cell division occurred during dark.…”

Section: Discussionmentioning

confidence: 97%

“…The approach used by Jüppner et al . () to study the cell cycle of the alga, including the synchronized growth of the photoautotrophic cell culture and the detailed metabolic phenotyping, can be combined with complex metabolic modelling as presented here, to understand the production and consumption of commercially useful metabolites. The experimental data needed to define the fate of storage molecules in the dark are the uptake rate of starch (or TAG) and the rate of protein synthesis.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Metabolic modelling and simulation of the light and dark metabolism of Chlamydomonas reinhardtii

2018

View full text Add to dashboard Cite

A metabolic network model of the green microalga Chlamydomonas reinhardtii was used to characterize photoautotrophic and heterotrophic (i.e. growth on stored compounds) growth under light and dark, respectively. The metabolic network comprised 2514 reactions distributed among nine intracellular compartments and the extracellular space. The metabolic network included all the key biochemical pathways for synthesis and metabolism of starch and triacylglycerols (TAGs). Under light and nitrogen limitation, the model simulated the accumulation of the energy-rich compounds (TAGs and starch) in the cell. In the dark, the model could simulate cell growth and maintenance on stored compounds. The model-predicted consumption rates of storage compounds (starch or TAGs) to enable growth in the dark, were found to be greater than the rates of synthesis under light. This implied utilization of the storage compounds for cell maintenance in the dark. Under constant illumination, the simulations of cell growth and intracellular starch content agreed closely with independent experimental data. In other simulations, compared with the case without photorespiration, light uptake rate increased 1.04-fold when the ratio of the rates of oxygenation and carboxylation (Rubisco) was 0.1. Although extensive experimental work exists on culture and physiology of microalgae, it does not allow quantitative predictions of the influence of dark metabolism on the productivity of metabolites to be made. This limitation is overcome using the present model. A metabolic network model of Chlamydomonas reinhardtii is shown to simulate growth and synthesis of energy-rich compounds (triacylglycerols and starch) under light. The same model also simulates dark growth and maintenance through consumption of the stored energy-rich compounds.

show abstract

Dynamics of lipids and metabolites during the cell cycle of Chlamydomonas reinhardtii

Cited by 44 publications

References 50 publications

Lipid catabolism in microalgae

Lipid catabolism in microalgae

The target of rapamycin kinase affects biomass accumulation and cell cycle progression by altering carbon/nitrogen balance in synchronized Chlamydomonas reinhardtii cells

Metabolic modelling and simulation of the light and dark metabolism of Chlamydomonas reinhardtii

Contact Info

Product

Resources

About