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Steichen S, Deshpande A, Mosey M, Loob J, Douchi D, Knoshaug EP, Brown S, Nielsen R, Weissman J, Carrillo LR, Laurens LML. Central transcriptional regulator controls photosynthetic growth and carbon storage in response to high light. Nat Commun 2024; 15:4842. [PMID: 38844786 PMCID: PMC11156908 DOI: 10.1038/s41467-024-49090-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/14/2024] [Indexed: 06/09/2024] Open
Abstract
Carbon capture and biochemical storage are some of the primary drivers of photosynthetic yield and productivity. To elucidate the mechanisms governing carbon allocation, we designed a photosynthetic light response test system for genetic and metabolic carbon assimilation tracking, using microalgae as simplified plant models. The systems biology mapping of high light-responsive photophysiology and carbon utilization dynamics between two variants of the same Picochlorum celeri species, TG1 and TG2 elucidated metabolic bottlenecks and transport rates of intermediates using instationary 13C-fluxomics. Simultaneous global gene expression dynamics showed 73% of the annotated genes responding within one hour, elucidating a singular, diel-responsive transcription factor, closely related to the CCA1/LHY clock genes in plants, with significantly altered expression in TG2. Transgenic P. celeri TG1 cells expressing the TG2 CCA1/LHY gene, showed 15% increase in growth rates and 25% increase in storage carbohydrate content, supporting a coordinating regulatory function for a single transcription factor.
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Affiliation(s)
- Seth Steichen
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Arnav Deshpande
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Megan Mosey
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Jessica Loob
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Damien Douchi
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Eric P Knoshaug
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA
| | - Stuart Brown
- ExxonMobil Technology and Engineering Co. (EMTEC), CLD286 Annandale, 1545 Route 22 East, Annandale, NJ, 08801, USA
| | - Robert Nielsen
- ExxonMobil Technology and Engineering Co. (EMTEC), CLD286 Annandale, 1545 Route 22 East, Annandale, NJ, 08801, USA
| | - Joseph Weissman
- ExxonMobil Technology and Engineering Co. (EMTEC), CLD286 Annandale, 1545 Route 22 East, Annandale, NJ, 08801, USA
| | - L Ruby Carrillo
- ExxonMobil Technology and Engineering Co. (EMTEC), CLD286 Annandale, 1545 Route 22 East, Annandale, NJ, 08801, USA
| | - Lieve M L Laurens
- Bioenergy Science and Technology Directorate, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO, 80401, USA.
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Gowda GAN, Pascua V, Raftery D. Anomalous Dynamics of Labile Metabolites in Cold Human Blood Detected Using 1H NMR Spectroscopy. Anal Chem 2023; 95:12923-12930. [PMID: 37582233 PMCID: PMC10528060 DOI: 10.1021/acs.analchem.3c02478] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Recent efforts in our laboratory have enabled access to an unprecedented number (∼90) of quantifiable metabolites in human blood by a simple nuclear magnetic resonance (NMR) spectroscopy method, which includes energy coenzymes, redox coenzymes, and antioxidants that are fundamental to cellular functions [ J. Magn. Reson. Open 2022, 12-13, 100082]. The coenzymes and antioxidants, however, are notoriously labile and are extremely sensitive to specimen harvesting, extraction, and measurement conditions. This problem is largely underappreciated and carries the risk of grossly inaccurate measurements and incorrect study outcomes. As a part of addressing this challenge, in this study, human blood specimens were comprehensively and quantitatively investigated using 1H NMR spectroscopy. Freshly drawn human blood specimens were treated or not treated with methanol, ethanol, or a mixture of methanol and chloroform, and stored on ice or on bench, at room temperature for different time periods from 0 to 24 h, prior to storing at -80 °C. Interestingly, the labile metabolite levels were stable in blood treated with an organic solvent. However, their levels in blood in untreated samples increased or decreased by factors of up to 5 or more within 3 h. Further, surprisingly, and contrary to the current knowledge about metabolite stability, the variation of coenzyme levels was more dramatic in blood stored on ice than on bench, at room temperature. In addition, unlike the generally observed phenomenon of oxidation of redox coenzymes, reduction was observed in untreated blood. Such preanalytical dynamics of the labile metabolites potentially arises from the active cellular metabolism. From the metabolomics perspective, the massive variation of the labile metabolite levels even in blood stored on ice is alarming and stresses the critical need to immediately quench the cellular metabolism for reliable analyses. Overall, the results provide compelling evidence that warrants a paradigm shift in the sample collection protocol for blood metabolomics involving labile metabolites.
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Affiliation(s)
- G. A. Nagana Gowda
- Northwest Metabolomics Research Center, University of Washington, Seattle, WA 98109
- Mitochondria and Metabolism Center, Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98109
| | - Vadim Pascua
- Northwest Metabolomics Research Center, University of Washington, Seattle, WA 98109
| | - Daniel Raftery
- Northwest Metabolomics Research Center, University of Washington, Seattle, WA 98109
- Mitochondria and Metabolism Center, Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98109
- Fred Hutchinson Cancer Center, Seattle, WA 98109
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Huang W, Krishnan A, Plett A, Meagher M, Linka N, Wang Y, Ren B, Findinier J, Redekop P, Fakhimi N, Kim RG, Karns DA, Boyle N, Posewitz MC, Grossman AR. Chlamydomonas mutants lacking chloroplast TRIOSE PHOSPHATE TRANSPORTER3 are metabolically compromised and light-sensitive. THE PLANT CELL 2023:koad095. [PMID: 36970811 DOI: 10.1093/plcell/koad095] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/08/2023] [Accepted: 03/23/2023] [Indexed: 06/18/2023]
Abstract
Modulation of photoassimilate export from the chloroplast is essential for controlling the distribution of fixed carbon in the cell and maintaining optimum photosynthetic rates. In this study we identified chloroplast TRIOSE PHOSPHATE/PHOSPHATE TRANSLOCATOR2 (CreTPT2) and CreTPT3 in the green alga Chlamydomonas (Chlamydomonas reinhardtii), which exhibit similar substrate specificities but whose encoding genes are differentially expressed over the diurnal cycle. We focused mostly on CreTPT3 because of its high level of expression and the severe phenotype exhibited by tpt3 relative to tpt2 mutants. Null mutants for CreTPT3 had a pleiotropic phenotype that affected growth, photosynthetic activities, metabolite profiles, carbon partitioning, and organelle-specific accumulation of H2O2. These analyses demonstrated that CreTPT3 is a dominant conduit on the chloroplast envelope for the transport of photoassimilates. In addition, CreTPT3 can serve as a safety valve that moves excess reductant out of the chloroplast and appears to be essential for preventing cells from experiencing oxidative stress and accumulating reactive oxygen species, even under low/moderate light intensities. Finally, our studies indicate subfunctionalization of the CreTPT transporters and suggest that there are differences in managing the export of photoassimilates from the chloroplasts of Chlamydomonas and vascular plants.
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Affiliation(s)
- Weichao Huang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Anagha Krishnan
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Anastasija Plett
- Institute of Plant Biochemistry, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Michelle Meagher
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Nicole Linka
- Institute of Plant Biochemistry, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Yongsheng Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
- School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Bijie Ren
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Justin Findinier
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Petra Redekop
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Neda Fakhimi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Rick G Kim
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Devin A Karns
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Nanette Boyle
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Matthew C Posewitz
- Department of Chemistry, Colorado School of Mines, Golden, CO 80401, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
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Wang B, Young JD. 13C-Isotope-Assisted Assessment of Metabolic Quenching During Sample Collection from Suspension Cell Cultures. Anal Chem 2022; 94:7787-7794. [PMID: 35613318 DOI: 10.1021/acs.analchem.1c05338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metabolomics and fluxomics are core approaches to directly profile and interrogate cellular metabolism in response to various genetic or environmental perturbations. In order to accurately measure the abundance and isotope enrichment of intracellular metabolites, cell culture samples must be rapidly harvested and cold quenched to preserve the in vivo metabolic state of the cells at the time of sample collection. When dealing with suspension cultures, this process is complicated by the need to separate the liquid culture media from cellular biomass prior to metabolite extraction. Here, we examine the efficacy of several commonly used metabolic quenching methods, using the model cyanobacterium Synechocystis sp. PCC 6803 as an example. Multiple 13C-labeled compounds, including 13C-bicarbonate, 13C-glucose, and 13C-glutamine, were used as tracers during the sample collection and the cold-quenching process to assess the extent of metabolic turnover after cells were harvested from culture flasks. We show that the combination of rapid filtration followed by 100% cold (-80 °C) methanol quenching exhibits the highest quenching efficiency, while mixing cell samples with a partially frozen 30% methanol slurry (-24 °C) followed by centrifugation is slightly less effective at quenching metabolism but enables less laborious sample processing. By contrast, rapidly mixing the cells with a saline ice slurry (∼0 °C) is less effective, as indicated by high isotope-labeling rates after sample harvest, while mixing the cells with 60% cold methanol (-65 °C) prior to centrifugation causes significant metabolite loss. This study demonstrates a rigorous, quantitative, and broadly applicable method for assessing the metabolic quenching efficacy of protocols used for sample collection in metabolomics and fluxomics studies.
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Affiliation(s)
- Bo Wang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, United States.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37235, United States
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