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Title: Hexokinase is necessary for glucose-mediated photosynthesis repression and lipid accumulation in a green alga

Abstract

Global primary production is driven largely by oxygenic photosynthesis, with algae as major contributors. The green alga Chromochloris zofingiensisreversibly switches off photosynthesis in the presence of glucose in the light and augments production of biofuel precursors(triacylglycerols) and the high-value antioxidant astaxanthin. Here we used forward genetics to reveal that this photosynthetic and metabolic switch is mediated by the glycolytic enzyme hexokinase (CzHXK1). In contrast to wild-type, glucose-treated hxk1 mutants do not shut off photosynthesis or accumulate astaxanthin, triacylglycerols, or cytoplasmic lipid droplets. We show that CzHXK1 is critical for the regulation of genes related to photosynthesis, ketocarotenoid synthesis and fatty acid biosynthesis. Sugars play fundamental regulatory roles in gene expression, physiology, metabolism, and growth in plants and animals, and we introduce a relatively simple, emerging model system to investigate conserved eukaryotic sugar sensing and signaling at the base of the green lineage.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]
  1. Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER). Biological Systems Science Division
OSTI Identifier:
1580873
Alternate Identifier(s):
OSTI ID: 1562686
Grant/Contract Number:  
AC02-05CH11231; SC0018301
Resource Type:
Accepted Manuscript
Journal Name:
Communications Biology
Additional Journal Information:
Journal Volume: 2; Journal Issue: 1; Journal ID: ISSN 2399-3642
Publisher:
Springer Nature
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Roth, Melissa S., Westcott, Daniel J., Iwai, Masakazu, and Niyogi, Krishna K. Hexokinase is necessary for glucose-mediated photosynthesis repression and lipid accumulation in a green alga. United States: N. p., 2019. Web. doi:10.1038/s42003-019-0577-1.
Roth, Melissa S., Westcott, Daniel J., Iwai, Masakazu, & Niyogi, Krishna K. Hexokinase is necessary for glucose-mediated photosynthesis repression and lipid accumulation in a green alga. United States. https://doi.org/10.1038/s42003-019-0577-1
Roth, Melissa S., Westcott, Daniel J., Iwai, Masakazu, and Niyogi, Krishna K. Thu . "Hexokinase is necessary for glucose-mediated photosynthesis repression and lipid accumulation in a green alga". United States. https://doi.org/10.1038/s42003-019-0577-1. https://www.osti.gov/servlets/purl/1580873.
@article{osti_1580873,
title = {Hexokinase is necessary for glucose-mediated photosynthesis repression and lipid accumulation in a green alga},
author = {Roth, Melissa S. and Westcott, Daniel J. and Iwai, Masakazu and Niyogi, Krishna K.},
abstractNote = {Global primary production is driven largely by oxygenic photosynthesis, with algae as major contributors. The green alga Chromochloris zofingiensisreversibly switches off photosynthesis in the presence of glucose in the light and augments production of biofuel precursors(triacylglycerols) and the high-value antioxidant astaxanthin. Here we used forward genetics to reveal that this photosynthetic and metabolic switch is mediated by the glycolytic enzyme hexokinase (CzHXK1). In contrast to wild-type, glucose-treated hxk1 mutants do not shut off photosynthesis or accumulate astaxanthin, triacylglycerols, or cytoplasmic lipid droplets. We show that CzHXK1 is critical for the regulation of genes related to photosynthesis, ketocarotenoid synthesis and fatty acid biosynthesis. Sugars play fundamental regulatory roles in gene expression, physiology, metabolism, and growth in plants and animals, and we introduce a relatively simple, emerging model system to investigate conserved eukaryotic sugar sensing and signaling at the base of the green lineage.},
doi = {10.1038/s42003-019-0577-1},
journal = {Communications Biology},
number = 1,
volume = 2,
place = {United States},
year = {Thu Sep 19 00:00:00 EDT 2019},
month = {Thu Sep 19 00:00:00 EDT 2019}
}

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Cited by: 17 works
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Figures / Tables:

Figure 1 Figure 1: Mutants reveal hexokinase1 as regulator of photosynthesis. (A) Gene structure of CzHXK1 with mutation location and type of hxk1 mutations as determined by whole-genome sequencing (See Methods). (B) Image of extracted pigments from representative samples of WT and hxk1 mutants after 84 h with and without glucose (Glc).more » (C) Maximum photosystem Ⅱ efficiency ($F$$v$ / $F$$m$) of hxk1 mutants is insensitive to glucose. Data represent means ± SD (n = 4 biological replicates, individual data points shown). (D) Photosynthetic apparatus of hxk1 mutants is insensitive to glucose. Immunoblot analysis of PSⅡ (D2, CP43), PSI (PsaA), cytochrome b6f (Cyt b6), light-harvesting complex of PSⅡ (LHCⅡ), light-harvesting complex of PSⅠ (LHCⅠ), and ATP synthase (AtpB) subunits after 84 h with and without glucose. The global AtpB antibody detected both the chloroplastic AtpB at ~50 kDa and the mitochondrial AtpB at ~70 kDa. Samples were normalized to total protein, and 10 μg of protein were loaded in each well. See Fig. 1G for stained total protein gel loading control. Images of the detected chemiluminescent signal on the complete membranes are available in Supplementary Fig. 4. (E) Net oxygen evolution (oxygen production in the light, 100 μmol photons m−2 s−1) of hxk1 mutants is insensitive to glucose. Data represent means ± SD (n = 3 biological replicates, individual data points shown). (F) Respiration (oxygen consumption in the dark) of hxk1 mutants is sensitive to glucose. Data represent means ± SD (n = 3 biological replicates, individual data points shown). (G) SDS-PAGE analysis of total protein extracted from whole cells and stained with Coomassie brilliant blue. Samples were normalized to total protein, and 10 μg of protein were loaded in each well. (H) Cell volume of hxk1 mutants increases with glucose. Data represent means ± SD (n = 4 biological replicates, individual data points shown).« less

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Works referenced in this record:

Interaction between Starch Breakdown, Acetate Assimilation, and Photosynthetic Cyclic Electron Flow in Chlamydomonas reinhardtii
journal, June 2012


A framework for variation discovery and genotyping using next-generation DNA sequencing data
journal, April 2011

  • DePristo, Mark A.; Banks, Eric; Poplin, Ryan
  • Nature Genetics, Vol. 43, Issue 5
  • DOI: 10.1038/ng.806

Glucose repression can be alleviated by reducing glucose phosphorylation rate in Saccharomyces cerevisiae
journal, February 2018


Master regulators in plant glucose signaling networks
journal, March 2014


Isozymes of Plant Hexokinase: Occurrence, Properties and Functions
journal, July 2007


The Chlamydomonas Genome Reveals the Evolution of Key Animal and Plant Functions
journal, October 2007

  • Merchant, S. S.; Prochnik, S. E.; Vallon, O.
  • Science, Vol. 318, Issue 5848, p. 245-250
  • DOI: 10.1126/science.1143609

The impact of nitrogen starvation on the dynamics of triacylglycerol accumulation in nine microalgae strains
journal, November 2012


Subdiffraction-resolution live-cell imaging for visualizing thylakoid membranes
journal, July 2018

  • Iwai, Masakazu; Roth, Melissa S.; Niyogi, Krishna K.
  • The Plant Journal, Vol. 96, Issue 1
  • DOI: 10.1111/tpj.14021

Isozymes of plant hexokinase: Occurrence, properties and functions
journal, March 2007


Dynamic and diverse sugar signaling
journal, October 2016


Fast and accurate short read alignment with Burrows-Wheeler transform
journal, May 2009


Plant Hexokinases are Multifaceted Proteins
journal, April 2017

  • Aguilera-Alvarado, G. Paulina; S�nchez-Nieto, Sobeida
  • Plant and Cell Physiology, Vol. 58, Issue 7
  • DOI: 10.1093/pcp/pcx062

A method for the quantitative recovery of protein in dilute solution in the presence of detergents and lipids
journal, April 1984


A central integrator of transcription networks in plant stress and energy signalling
journal, August 2007

  • Baena-González, Elena; Rolland, Filip; Thevelein, Johan M.
  • Nature, Vol. 448, Issue 7156
  • DOI: 10.1038/nature06069

SUGAR SENSING AND SIGNALING IN PLANTS: Conserved and Novel Mechanisms
journal, June 2006


Nitrogen-depleted Chlorella zofingiensis produces astaxanthin, ketolutein and their fatty acid esters: a carotenoid metabolism study
journal, May 2014

  • Mulders, Kim J. M.; Weesepoel, Yannick; Bodenes, Pierre
  • Journal of Applied Phycology, Vol. 27, Issue 1
  • DOI: 10.1007/s10811-014-0333-3

Glucose–TOR signalling reprograms the transcriptome and activates meristems
journal, March 2013

  • Xiong, Yan; McCormack, Matthew; Li, Lei
  • Nature, Vol. 496, Issue 7444
  • DOI: 10.1038/nature12030

Chromosome-level genome assembly and transcriptome of the green alga Chromochloris zofingiensis illuminates astaxanthin production
journal, May 2017

  • Roth, Melissa S.; Cokus, Shawn J.; Gallaher, Sean D.
  • Proceedings of the National Academy of Sciences, Vol. 114, Issue 21
  • DOI: 10.1073/pnas.1619928114

Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT Method
journal, December 2001


Chlorella zofingiensis as an Alternative Microalgal Producer of Astaxanthin: Biology and Industrial Potential
journal, June 2014

  • Liu, Jin; Sun, Zheng; Gerken, Henri
  • Marine Drugs, Vol. 12, Issue 6
  • DOI: 10.3390/md12063487

Regulation of Oxygenic Photosynthesis during Trophic Transitions in the Green Alga Chromochloris zofingiensis
journal, February 2019

  • Roth, Melissa S.; Gallaher, Sean D.; Westcott, Daniel J.
  • The Plant Cell, Vol. 31, Issue 3
  • DOI: 10.1105/tpc.18.00742

Localization of the Primary Metabolic Block Produced by 2-Deoxyglucose
journal, February 1957


Nitrogen-depleted Chlorella zofingiensis produces astaxanthin, ketolutein and their fatty acid esters: a carotenoid metabolism study
journal, May 2014

  • Mulders, Kim J. M.; Weesepoel, Yannick; Bodenes, Pierre
  • Journal of Applied Phycology, Vol. 27, Issue 1
  • DOI: 10.1007/s10811-014-0333-3

Master regulators in plant glucose signaling networks
journal, March 2014


The impact of nitrogen starvation on the dynamics of triacylglycerol accumulation in nine microalgae strains
journal, November 2012


Dynamic and diverse sugar signaling
journal, October 2016


Pigment and Structural Changes in Chlorella zofingiensis upon Light and Nitrogen Stress
journal, July 1995


A central integrator of transcription networks in plant stress and energy signalling
journal, August 2007

  • Baena-González, Elena; Rolland, Filip; Thevelein, Johan M.
  • Nature, Vol. 448, Issue 7156
  • DOI: 10.1038/nature06069

A framework for variation discovery and genotyping using next-generation DNA sequencing data
journal, April 2011

  • DePristo, Mark A.; Banks, Eric; Poplin, Ryan
  • Nature Genetics, Vol. 43, Issue 5
  • DOI: 10.1038/ng.806

A type 2C protein phosphatase activates high-affinity nitrate uptake by dephosphorylating NRT2.1
journal, March 2021


Targeted introduction of heritable point mutations into the plant mitochondrial genome
journal, March 2022


Targeted A-to-G base editing of chloroplast DNA in plants
journal, December 2022


Glucose repression can be alleviated by reducing glucose phosphorylation rate in Saccharomyces cerevisiae
journal, February 2018


Chromosome-level genome assembly and transcriptome of the green alga Chromochloris zofingiensis illuminates astaxanthin production
journal, May 2017

  • Roth, Melissa S.; Cokus, Shawn J.; Gallaher, Sean D.
  • Proceedings of the National Academy of Sciences, Vol. 114, Issue 21
  • DOI: 10.1073/pnas.1619928114

Hexokinase 2 Is an Intracellular Glucose Sensor of Yeast Cells That Maintains the Structure and Activity of Mig1 Protein Repressor Complex
journal, February 2016

  • Vega, Montserrat; Riera, Alberto; Fernández-Cid, Alejandra
  • Journal of Biological Chemistry, Vol. 291, Issue 14
  • DOI: 10.1074/jbc.m115.711408

The Glucose-regulated Nuclear Localization of Hexokinase 2 in Saccharomyces cerevisiae Is Mig1-dependent
journal, January 2004

  • Ahuatzi, Deifilia; Herrero, Pilar; de la Cera, Tamara
  • Journal of Biological Chemistry, Vol. 279, Issue 14
  • DOI: 10.1074/jbc.m313431200

Plant Hexokinases are Multifaceted Proteins
journal, April 2017

  • Aguilera-Alvarado, G. Paulina; S�nchez-Nieto, Sobeida
  • Plant and Cell Physiology, Vol. 58, Issue 7
  • DOI: 10.1093/pcp/pcx062

Regulation of Oxygenic Photosynthesis during Trophic Transitions in the Green Alga Chromochloris zofingiensis
journal, February 2019

  • Roth, Melissa S.; Gallaher, Sean D.; Westcott, Daniel J.
  • The Plant Cell, Vol. 31, Issue 3
  • DOI: 10.1105/tpc.18.00742

Transcriptome and de novo analysis of Rosa xanthina f. spontanea in response to cold stress
journal, October 2021


RNA Purification from the Unicellular Green Alga, Chromochloris zofingiensis
journal, January 2018


Hexokinase as a Sugar Sensor in Higher Plants
journal, January 1997

  • Jang, Jyan-Chyun; Leon, Patricia; Zhou, Li
  • The Plant Cell, Vol. 9, Issue 1
  • DOI: 10.2307/3870367

Chlorella zofingiensis as an Alternative Microalgal Producer of Astaxanthin: Biology and Industrial Potential
journal, June 2014

  • Liu, Jin; Sun, Zheng; Gerken, Henri
  • Marine Drugs, Vol. 12, Issue 6
  • DOI: 10.3390/md12063487

Works referencing / citing this record: