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Sah SK, Fan J, Blanford J, Shanklin J, Xu C. Physiological Functions of Phospholipid:Diacylglycerol Acyltransferases. PLANT & CELL PHYSIOLOGY 2024; 65:863-871. [PMID: 37702708 DOI: 10.1093/pcp/pcad106] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/01/2023] [Accepted: 09/08/2023] [Indexed: 09/14/2023]
Abstract
Triacylglycerol (TAG) is among the most energy dense storage forms of reduced carbon in living systems. TAG metabolism plays critical roles in cellular energy balance, lipid homeostasis, cell growth and stress responses. In higher plants, microalgae and fungi, TAG is assembled by acyl-CoA-dependent and acyl-CoA-independent pathways catalyzed by diacylglycerol (DAG) acyltransferase and phospholipid:DAG acyltransferase (PDAT), respectively. This review contains a summary of the current understanding of the physiological functions of PDATs. Emphasis is placed on their role in lipid remodeling and lipid homeostasis in response to abiotic stress or perturbations in lipid metabolism.
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Affiliation(s)
- Saroj Kumar Sah
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilian Fan
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jantana Blanford
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | | | - Changcheng Xu
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
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2
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Barbosa AD, Siniossoglou S. Membranes that make fat: roles of membrane lipids as acyl donors for triglyceride synthesis and organelle function. FEBS Lett 2024; 598:1226-1234. [PMID: 38140812 DOI: 10.1002/1873-3468.14793] [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: 11/02/2023] [Revised: 12/05/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023]
Abstract
Triglycerides constitute an inert storage form for fatty acids deposited in lipid droplets and are mobilized to provide metabolic energy or membrane building blocks. The biosynthesis of triglycerides is highly conserved within eukaryotes and normally involves the sequential esterification of activated fatty acids with a glycerol backbone. Some eukaryotes, however, can also use cellular membrane lipids as direct fatty acid donors for triglyceride synthesis. The biological significance of a pathway that generates triglycerides at the expense of organelle membranes has remained elusive. Here we review current knowledge on how cells use membrane lipids as fatty acid donors for triglyceride synthesis and discuss the hypothesis that a primary function of this pathway is to regulate membrane lipid remodeling and organelle function.
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Affiliation(s)
- Antonio D Barbosa
- Cambridge Institute for Medical Research, University of Cambridge, UK
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3
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K. Raval P, MacLeod AI, Gould SB. A molecular atlas of plastid and mitochondrial proteins reveals organellar remodeling during plant evolutionary transitions from algae to angiosperms. PLoS Biol 2024; 22:e3002608. [PMID: 38713727 PMCID: PMC11135702 DOI: 10.1371/journal.pbio.3002608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 05/29/2024] [Accepted: 03/28/2024] [Indexed: 05/09/2024] Open
Abstract
Algae and plants carry 2 organelles of endosymbiotic origin that have been co-evolving in their host cells for more than a billion years. The biology of plastids and mitochondria can differ significantly across major lineages and organelle changes likely accompanied the adaptation to new ecological niches such as the terrestrial habitat. Based on organelle proteome data and the genomes of 168 phototrophic (Archaeplastida) versus a broad range of 518 non-phototrophic eukaryotes, we screened for changes in plastid and mitochondrial biology across 1 billion years of evolution. Taking into account 331,571 protein families (or orthogroups), we identify 31,625 protein families that are unique to primary plastid-bearing eukaryotes. The 1,906 and 825 protein families are predicted to operate in plastids and mitochondria, respectively. Tracing the evolutionary history of these protein families through evolutionary time uncovers the significant remodeling the organelles experienced from algae to land plants. The analyses of gained orthogroups identifies molecular changes of organelle biology that connect to the diversification of major lineages and facilitated major transitions from chlorophytes en route to the global greening and origin of angiosperms.
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Affiliation(s)
- Parth K. Raval
- Institute for Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Alexander I. MacLeod
- Institute for Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sven B. Gould
- Institute for Molecular Evolution, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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4
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Plouviez M, Dubreucq E. Key Proteomics Tools for Fundamental and Applied Microalgal Research. Proteomes 2024; 12:13. [PMID: 38651372 PMCID: PMC11036299 DOI: 10.3390/proteomes12020013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/28/2024] [Accepted: 04/02/2024] [Indexed: 04/25/2024] Open
Abstract
Microscopic, photosynthetic prokaryotes and eukaryotes, collectively referred to as microalgae, are widely studied to improve our understanding of key metabolic pathways (e.g., photosynthesis) and for the development of biotechnological applications. Omics technologies, which are now common tools in biological research, have been shown to be critical in microalgal research. In the past decade, significant technological advancements have allowed omics technologies to become more affordable and efficient, with huge datasets being generated. In particular, where studies focused on a single or few proteins decades ago, it is now possible to study the whole proteome of a microalgae. The development of mass spectrometry-based methods has provided this leap forward with the high-throughput identification and quantification of proteins. This review specifically provides an overview of the use of proteomics in fundamental (e.g., photosynthesis) and applied (e.g., lipid production for biofuel) microalgal research, and presents future research directions in this field.
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Affiliation(s)
- Maxence Plouviez
- School of Agriculture and Environment, Massey University, Palmerston North 4410, New Zealand
- The Cawthron Institute, Nelson 7010, New Zealand
| | - Eric Dubreucq
- Agropolymer Engineering and Emerging Technologies, L’Institut Agro Montpellier, 34060 Montpellier, France;
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5
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Pan Y, Zhang W, Wang X, Jouhet J, Maréchal E, Liu J, Xia XQ, Hu H. Allele-dependent expression and functionality of lipid enzyme phospholipid:diacylglycerol acyltransferase affect diatom carbon storage and growth. PLANT PHYSIOLOGY 2024; 194:1024-1040. [PMID: 37930282 DOI: 10.1093/plphys/kiad581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/06/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
In the acyl-CoA-independent pathway of triacylglycerol (TAG) synthesis unique to plants, fungi, and algae, TAG formation is catalyzed by the enzyme phospholipid:diacylglycerol acyltransferase (PDAT). The unique PDAT gene of the model diatom Phaeodactylum tricornutum strain CCMP2561 boasts 47 single nucleotide variants within protein coding regions of the alleles. To deepen our understanding of TAG synthesis, we observed the allele-specific expression of PDAT by the analysis of 87 published RNA-sequencing (RNA-seq) data and experimental validation. The transcription of one of the two PDAT alleles, Allele 2, could be specifically induced by decreasing nitrogen concentrations. Overexpression of Allele 2 in P. tricornutum substantially enhanced the accumulation of TAG by 44% to 74% under nutrient stress; however, overexpression of Allele 1 resulted in little increase of TAG accumulation. Interestingly, a more serious growth inhibition was observed in the PDAT Allele 1 overexpression strains compared with Allele 2 counterparts. Heterologous expression in yeast (Saccharomyces cerevisiae) showed that enzymes encoded by PDAT Allele 2 but not Allele 1 had TAG biosynthetic activity, and 7 N-terminal and 3 C-terminal amino acid variants between the 2 allele-encoded proteins substantially affected enzymatic activity. P. tricornutum PDAT, localized in the innermost chloroplast membrane, used monogalactosyldiacylglycerol and phosphatidylcholine as acyl donors as demonstrated by the increase of the 2 lipids in PDAT knockout lines, which indicated a common origin in evolution with green algal PDATs. Our study reveals unequal roles among allele-encoded PDATs in mediating carbon storage and growth in response to nitrogen stress and suggests an unsuspected strategy toward lipid and biomass improvement for biotechnological purposes.
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Affiliation(s)
- Yufang Pan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wanting Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiaofei Wang
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Xiao-Qin Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanhua Hu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Füssy Z, Oborník M. Complex Endosymbioses I: From Primary to Complex Plastids, Serial Endosymbiotic Events. Methods Mol Biol 2024; 2776:21-41. [PMID: 38502496 DOI: 10.1007/978-1-0716-3726-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
A considerable part of the diversity of eukaryotic phototrophs consists of algae with plastids that evolved from endosymbioses between two eukaryotes. These complex plastids are characterized by a high number of envelope membranes (more than two) and some of them contain a residual nucleus of the endosymbiotic alga called a nucleomorph. Complex plastid-bearing algae are thus chimeric cell assemblies, eukaryotic symbionts living in a eukaryotic host. In contrast, the primary plastids of the Archaeplastida (plants, green algae, red algae, and glaucophytes) possibly evolved from a single endosymbiosis with a cyanobacterium and are surrounded by two membranes. Complex plastids have been acquired several times by unrelated groups of eukaryotic heterotrophic hosts, suggesting that complex plastids are somewhat easier to obtain than primary plastids. Evidence suggests that complex plastids arose twice independently in the green lineage (euglenophytes and chlorarachniophytes) through secondary endosymbiosis, and four times in the red lineage, first through secondary endosymbiosis in cryptophytes, then by higher-order events in stramenopiles, alveolates, and haptophytes. Engulfment of primary and complex plastid-containing algae by eukaryotic hosts (secondary, tertiary, and higher-order endosymbioses) is also responsible for numerous plastid replacements in dinoflagellates. Plastid endosymbiosis is accompanied by massive gene transfer from the endosymbiont to the host nucleus and cell adaptation of both endosymbiotic partners, which is related to the trophic switch to phototrophy and loss of autonomy of the endosymbiont. Such a process is essential for the metabolic integration and division control of the endosymbiont in the host. Although photosynthesis is the main advantage of acquiring plastids, loss of photosynthesis often occurs in algae with complex plastids. This chapter summarizes the essential knowledge of the acquisition, evolution, and function of complex plastids.
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Affiliation(s)
- Zoltán Füssy
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Miroslav Oborník
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
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7
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Caspari OD, Garrido C, Law CO, Choquet Y, Wollman FA, Lafontaine I. Converting antimicrobial into targeting peptides reveals key features governing protein import into mitochondria and chloroplasts. PLANT COMMUNICATIONS 2023:100555. [PMID: 36733255 PMCID: PMC10363480 DOI: 10.1016/j.xplc.2023.100555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/18/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
We asked what peptide features govern targeting to the mitochondria versus the chloroplast, using antimicrobial peptides as a starting point. This approach was inspired by the endosymbiotic hypothesis that organelle-targeting peptides derive from antimicrobial amphipathic peptides delivered by the host cell, to which organelle progenitors became resistant. To explore the molecular changes required to convert antimicrobial into targeting peptides, we expressed a set of 13 antimicrobial peptides in Chlamydomonas reinhardtii. Peptides were systematically modified to test distinctive features of mitochondrion- and chloroplast-targeting peptides, and we assessed their targeting potential by following the intracellular localization and maturation of a Venus fluorescent reporter used as a cargo protein. Mitochondrial targeting can be achieved by some unmodified antimicrobial peptide sequences. Targeting to both organelles is improved by replacing lysines with arginines. Chloroplast targeting is enabled by the presence of flanking unstructured sequences, additional constraints consistent with chloroplast endosymbiosis having occurred in a cell that already contained mitochondria. If indeed targeting peptides evolved from antimicrobial peptides, then required modifications imply a temporal evolutionary scenario with an early exchange of cationic residues and a late acquisition of chloroplast-specific motifs.
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Affiliation(s)
- Oliver D Caspari
- UMR7141 (CNRS/Sorbonne Université), Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France.
| | - Clotilde Garrido
- UMR7141 (CNRS/Sorbonne Université), Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Chris O Law
- Centre for Microscopy and Cellular Imaging, Biology Department Loyola Campus of Concordia University, 7141 Sherbrooke W., Montréal, QC H4B 1R6, Canada
| | - Yves Choquet
- UMR7141 (CNRS/Sorbonne Université), Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Francis-André Wollman
- UMR7141 (CNRS/Sorbonne Université), Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Ingrid Lafontaine
- UMR7141 (CNRS/Sorbonne Université), Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France.
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8
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Liu S, Storti M, Finazzi G, Bowler C, Dorrell RG. A metabolic, phylogenomic and environmental atlas of diatom plastid transporters from the model species Phaeodactylum. FRONTIERS IN PLANT SCIENCE 2022; 13:950467. [PMID: 36212359 PMCID: PMC9546453 DOI: 10.3389/fpls.2022.950467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Diatoms are an important group of algae, contributing nearly 40% of total marine photosynthetic activity. However, the specific molecular agents and transporters underpinning the metabolic efficiency of the diatom plastid remain to be revealed. We performed in silico analyses of 70 predicted plastid transporters identified by genome-wide searches of Phaeodactylum tricornutum. We considered similarity with Arabidopsis thaliana plastid transporters, transcriptional co-regulation with genes encoding core plastid metabolic pathways and with genes encoded in the mitochondrial genomes, inferred evolutionary histories using single-gene phylogeny, and environmental expression trends using Tara Oceans meta-transcriptomics and meta-genomes data. Our data reveal diatoms conserve some of the ion, nucleotide and sugar plastid transporters associated with plants, such as non-specific triose phosphate transporters implicated in the transport of phosphorylated sugars, NTP/NDP and cation exchange transporters. However, our data also highlight the presence of diatom-specific transporter functions, such as carbon and amino acid transporters implicated in intricate plastid-mitochondria crosstalk events. These confirm previous observations that substrate non-specific triose phosphate transporters (TPT) may exist as principal transporters of phosphorylated sugars into and out of the diatom plastid, alongside suggesting probable agents of NTP exchange. Carbon and amino acid transport may be related to intricate metabolic plastid-mitochondria crosstalk. We additionally provide evidence from environmental meta-transcriptomic/meta- genomic data that plastid transporters may underpin diatom sensitivity to ocean warming, and identify a diatom plastid transporter (J43171) whose expression may be positively correlated with temperature.
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Affiliation(s)
- Shun Liu
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Centre National De La Recherche Scientifique (CNRS), Institut National De La Santé Et De La Recherche Médicale (INSERM), Université Paris Sciences et Lettres (PSL), Paris, France
- CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, Paris, France
| | - Mattia Storti
- Univ. Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique Energies Alternatives (CEA), Institut National Recherche Agriculture Alimentation Environnement (INRAE), Interdisciplinary Research Institute of Grenoble (IRIG), Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Grenoble, France
| | - Giovanni Finazzi
- Univ. Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique Energies Alternatives (CEA), Institut National Recherche Agriculture Alimentation Environnement (INRAE), Interdisciplinary Research Institute of Grenoble (IRIG), Laboratoire de Physiologie Cellulaire et Végétale (LPCV), Grenoble, France
| | - Chris Bowler
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Centre National De La Recherche Scientifique (CNRS), Institut National De La Santé Et De La Recherche Médicale (INSERM), Université Paris Sciences et Lettres (PSL), Paris, France
- CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, Paris, France
| | - Richard G. Dorrell
- Institut de Biologie de l’Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Centre National De La Recherche Scientifique (CNRS), Institut National De La Santé Et De La Recherche Médicale (INSERM), Université Paris Sciences et Lettres (PSL), Paris, France
- CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, Paris, France
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9
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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10
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Caspari OD. Transit Peptides Often Require Downstream Unstructured Sequence for Efficient Chloroplast Import in Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2022; 13:825797. [PMID: 35646025 PMCID: PMC9133816 DOI: 10.3389/fpls.2022.825797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
The N-terminal sequence stretch that defines subcellular targeting for most nuclear encoded chloroplast proteins is usually considered identical to the sequence that is cleaved upon import. Yet here this study shows that for eight out of ten tested Chlamydomonas chloroplast transit peptides, significant additional sequence stretches past the cleavage site are required to enable efficient chloroplast import of heterologous cargo proteins. Analysis of Chlamydomonas cTPs with known cleavage sites and replacements of native post-cleavage residues with alternative sequences points to a role for unstructured sequence at mature protein N-termini.
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11
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Saint-Sorny M, Brzezowski P, Arrivault S, Alric J, Johnson X. Interactions Between Carbon Metabolism and Photosynthetic Electron Transport in a Chlamydomonas reinhardtii Mutant Without CO 2 Fixation by RuBisCO. FRONTIERS IN PLANT SCIENCE 2022; 13:876439. [PMID: 35574084 PMCID: PMC9096841 DOI: 10.3389/fpls.2022.876439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
A Chlamydomonas reinhardtii RuBisCO-less mutant, ΔrbcL, was used to study carbohydrate metabolism without fixation of atmospheric carbon. The regulatory mechanism(s) that control linear electron flow, known as "photosynthetic control," are amplified in ΔrbcL at the onset of illumination. With the aim to understand the metabolites that control this regulatory response, we have correlated the kinetics of primary carbon metabolites to chlorophyll fluorescence induction curves. We identify that ΔrbcL in the absence of acetate generates adenosine triphosphate (ATP) via photosynthetic electron transfer reactions. Also, metabolites of the Calvin Benson Bassham (CBB) cycle are responsive to the light. Indeed, ribulose 1,5-bisphosphate (RuBP), the last intermediate before carboxylation by Ribulose-1,5-bisphosphate carboxylase-oxygenase, accumulates significantly with time, and CBB cycle intermediates for RuBP regeneration, dihydroxyacetone phosphate (DHAP), pentose phosphates and ribose-5-phosphate (R5P) are rapidly accumulated in the first seconds of illumination, then consumed, showing that although the CBB is blocked, these enzymes are still transiently active. In opposition, in the presence of acetate, consumption of CBB cycle intermediates is strongly diminished, suggesting that the link between light and primary carbon metabolism is almost lost. Phosphorylated hexoses and starch accumulate significantly. We show that acetate uptake results in heterotrophic metabolism dominating phototrophic metabolism, with glyoxylate and tricarboxylic acid (TCA) cycle intermediates being the most highly represented metabolites, specifically succinate and malate. These findings allow us to hypothesize which metabolites and metabolic pathways are relevant to the upregulation of processes like cyclic electron flow that are implicated in photosynthetic control mechanisms.
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Affiliation(s)
- Maureen Saint-Sorny
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | - Pawel Brzezowski
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | | | - Jean Alric
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- CEA, CNRS, UMR 7265, BIAM, CEA Cadarache, Aix-Marseille Université, Saint-Paul-lez-Durance, France
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12
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Harnessing the Algal Chloroplast for Heterologous Protein Production. Microorganisms 2022; 10:microorganisms10040743. [PMID: 35456794 PMCID: PMC9025058 DOI: 10.3390/microorganisms10040743] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 02/04/2023] Open
Abstract
Photosynthetic microbes are gaining increasing attention as heterologous hosts for the light-driven, low-cost production of high-value recombinant proteins. Recent advances in the manipulation of unicellular algal genomes offer the opportunity to establish engineered strains as safe and viable alternatives to conventional heterotrophic expression systems, including for their use in the feed, food, and biopharmaceutical industries. Due to the relatively small size of their genomes, algal chloroplasts are excellent targets for synthetic biology approaches, and are convenient subcellular sites for the compartmentalized accumulation and storage of products. Different classes of recombinant proteins, including enzymes and peptides with therapeutical applications, have been successfully expressed in the plastid of the model organism Chlamydomonas reinhardtii, and of a few other species, highlighting the emerging potential of transplastomic algal biotechnology. In this review, we provide a unified view on the state-of-the-art tools that are available to introduce protein-encoding transgenes in microalgal plastids, and discuss the main (bio)technological bottlenecks that still need to be addressed to develop robust and sustainable green cell biofactories.
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13
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Huang G, Zhao D, Lan C, Wu B, Li X, Lou S, Zheng Y, Huang Y, Hu Z, Jia B. Glucose-assisted trophic conversion of Chlamydomonas reinhardtii by expression of glucose transporter GLUT1. ALGAL RES 2022. [DOI: 10.1016/j.algal.2021.102626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Zhang N, Pazouki L, Nguyen H, Jacobshagen S, Bigge BM, Xia M, Mattoon EM, Klebanovych A, Sorkin M, Nusinow DA, Avasthi P, Czymmek KJ, Zhang R. Comparative Phenotyping of Two Commonly Used Chlamydomonas reinhardtii Background Strains: CC-1690 (21gr) and CC-5325 (The CLiP Mutant Library Background). PLANTS (BASEL, SWITZERLAND) 2022; 11:585. [PMID: 35270055 PMCID: PMC8912731 DOI: 10.3390/plants11050585] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 05/02/2023]
Abstract
The unicellular green alga Chlamydomonas reinhardtii is an excellent model organism to investigate many essential cellular processes in photosynthetic eukaryotes. Two commonly used background strains of Chlamydomonas are CC-1690 and CC-5325. CC-1690, also called 21gr, has been used for the Chlamydomonas genome project and several transcriptome analyses. CC-5325 is the background strain for the Chlamydomonas Library Project (CLiP). Photosynthetic performance in CC-5325 has not been evaluated in comparison with CC-1690. Additionally, CC-5325 is often considered to be cell-wall deficient, although detailed analysis is missing. The circadian rhythms in CC-5325 are also unclear. To fill these knowledge gaps and facilitate the use of the CLiP mutant library for various screens, we performed phenotypic comparisons between CC-1690 and CC-5325. Our results showed that CC-5325 grew faster heterotrophically in dark and equally well in mixotrophic liquid medium as compared to CC-1690. CC-5325 had lower photosynthetic efficiency and was more heat-sensitive than CC-1690. Furthermore, CC-5325 had an intact cell wall which had comparable integrity to that in CC-1690 but appeared to have reduced thickness. Additionally, CC-5325 could perform phototaxis, but could not maintain a sustained circadian rhythm of phototaxis as CC1690 did. Finally, in comparison to CC-1690, CC-5325 had longer cilia in the medium with acetate but slower swimming speed in the medium without nitrogen and acetate. Our results will be useful for researchers in the Chlamydomonas community to choose suitable background strains for mutant analysis and employ the CLiP mutant library for genome-wide mutant screens under appropriate conditions, especially in the areas of photosynthesis, thermotolerance, cell wall, and circadian rhythms.
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Affiliation(s)
- Ningning Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Leila Pazouki
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Huong Nguyen
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Sigrid Jacobshagen
- Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA;
| | - Brae M. Bigge
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (B.M.B.); (P.A.)
| | - Ming Xia
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Erin M. Mattoon
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
- Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, MO 63130, USA
| | - Anastasiya Klebanovych
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Maria Sorkin
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
- Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, MO 63130, USA
| | - Dmitri A. Nusinow
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Prachee Avasthi
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; (B.M.B.); (P.A.)
| | - Kirk J. Czymmek
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
| | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA; (N.Z.); (L.P.); (H.N.); (M.X.); (E.M.M.); (A.K.); (M.S.); (D.A.N.); (K.J.C.)
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15
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Structural analysis revealed a novel conformation of the NTRC reductase domain from Chlamydomonas reinhardtii. J Struct Biol 2021; 214:107829. [PMID: 34974142 DOI: 10.1016/j.jsb.2021.107829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/07/2021] [Accepted: 12/27/2021] [Indexed: 11/20/2022]
Abstract
In plant chloroplasts, thiol regulation is driven by two systems. One relies on the activity of thioredoxins through their light dependent reduction by ferredoxin via a ferredoxin-thioredoxin reductase (FTR). In the other system, a NADPH-dependent redox regulation is driven by a NADPH-thioredoxin reductase C (NTRC). While the thioredoxin system has been deeply studied, a more thorough understanding of the function of this plant specific NTRC is desirable. NTRC is a single polypeptide harbouring a thioredoxin domain (Trx) at the C-terminus of a NADPH-dependent Thioredoxin reductase (TrxR). To provide functional and structural insights, we studied the crystal structure of the TrxR domain of the NTRC from Chlamydomonas reinhardtii (CrNTRC, Cre01.g054150.t1.2) and its Cys136Ser (C136S) mutant, which is characterized by the mutation of the resolving cysteine in the active site of the TrxR domain. Furthermore, we confirmed the role of NTRC as electron donor for 2-Cys peroxiredoxin (PRX) also in C. reinhardtii. The structural data of TrxR were employed to develop a scheme of action which addresses electron transfer between TrxR and Trx of NTRC and between NTRC and its substrates.
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16
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Wakao S, Shih PM, Guan K, Schackwitz W, Ye J, Patel D, Shih RM, Dent RM, Chovatia M, Sharma A, Martin J, Wei CL, Niyogi KK. Discovery of photosynthesis genes through whole-genome sequencing of acetate-requiring mutants of Chlamydomonas reinhardtii. PLoS Genet 2021; 17:e1009725. [PMID: 34492001 PMCID: PMC8448359 DOI: 10.1371/journal.pgen.1009725] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 09/17/2021] [Accepted: 07/19/2021] [Indexed: 11/18/2022] Open
Abstract
Large-scale mutant libraries have been indispensable for genetic studies, and the development of next-generation genome sequencing technologies has greatly advanced efforts to analyze mutants. In this work, we sequenced the genomes of 660 Chlamydomonas reinhardtii acetate-requiring mutants, part of a larger photosynthesis mutant collection previously generated by insertional mutagenesis with a linearized plasmid. We identified 554 insertion events from 509 mutants by mapping the plasmid insertion sites through paired-end sequences, in which one end aligned to the plasmid and the other to a chromosomal location. Nearly all (96%) of the events were associated with deletions, duplications, or more complex rearrangements of genomic DNA at the sites of plasmid insertion, and together with deletions that were unassociated with a plasmid insertion, 1470 genes were identified to be affected. Functional annotations of these genes were enriched in those related to photosynthesis, signaling, and tetrapyrrole synthesis as would be expected from a library enriched for photosynthesis mutants. Systematic manual analysis of the disrupted genes for each mutant generated a list of 253 higher-confidence candidate photosynthesis genes, and we experimentally validated two genes that are essential for photoautotrophic growth, CrLPA3 and CrPSBP4. The inventory of candidate genes includes 53 genes from a phylogenomically defined set of conserved genes in green algae and plants. Altogether, 70 candidate genes encode proteins with previously characterized functions in photosynthesis in Chlamydomonas, land plants, and/or cyanobacteria; 14 genes encode proteins previously shown to have functions unrelated to photosynthesis. Among the remaining 169 uncharacterized genes, 38 genes encode proteins without any functional annotation, signifying that our results connect a function related to photosynthesis to these previously unknown proteins. This mutant library, with genome sequences that reveal the molecular extent of the chromosomal lesions and resulting higher-confidence candidate genes, will aid in advancing gene discovery and protein functional analysis in photosynthesis.
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Affiliation(s)
- Setsuko Wakao
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Patrick M. Shih
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Division of Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, California, United States of America
- Innovative Genomics Institute, University of California, Berkeley, California, United States of America
| | - Katharine Guan
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
| | - Wendy Schackwitz
- Joint Genome Institute, Berkeley, California, United States of America
| | - Joshua Ye
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
| | - Dhruv Patel
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Robert M. Shih
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Rachel M. Dent
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Mansi Chovatia
- Joint Genome Institute, Berkeley, California, United States of America
| | - Aditi Sharma
- Joint Genome Institute, Berkeley, California, United States of America
| | - Joel Martin
- Joint Genome Institute, Berkeley, California, United States of America
| | - Chia-Lin Wei
- Joint Genome Institute, Berkeley, California, United States of America
| | - Krishna K. Niyogi
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
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17
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Kachroo P, Burch-Smith TM, Grant M. An Emerging Role for Chloroplasts in Disease and Defense. ANNUAL REVIEW OF PHYTOPATHOLOGY 2021; 59:423-445. [PMID: 34432508 DOI: 10.1146/annurev-phyto-020620-115813] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chloroplasts are key players in plant immune signaling, contributing to not only de novo synthesis of defensive phytohormones but also the generation of reactive oxygen and nitrogen species following activation of pattern recognition receptors or resistance (R) proteins. The local hypersensitive response (HR) elicited by R proteins is underpinned by chloroplast-generated reactive oxygen species. HR-induced lipid peroxidation generates important chloroplast-derived signaling lipids essential to the establishment of systemic immunity. As a consequence of this pivotal role in immunity, pathogens deploy effector complements that directly or indirectly target chloroplasts to attenuate chloroplast immunity (CI). Our review summarizes the current knowledge of CI signaling and highlights common pathogen chloroplast targets and virulence strategies. We address emerging insights into chloroplast retrograde signaling in immune responses and gaps in our knowledge, including the importance of understanding chloroplast heterogeneity and chloroplast involvement in intraorganellular interactions in host immunity.
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Affiliation(s)
- Pradeep Kachroo
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546, USA
| | - Tessa M Burch-Smith
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Murray Grant
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK;
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18
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Moulin SLY, Beyly-Adriano A, Cuiné S, Blangy S, Légeret B, Floriani M, Burlacot A, Sorigué D, Samire PP, Li-Beisson Y, Peltier G, Beisson F. Fatty acid photodecarboxylase is an ancient photoenzyme that forms hydrocarbons in the thylakoids of algae. PLANT PHYSIOLOGY 2021; 186:1455-1472. [PMID: 33856460 PMCID: PMC8260138 DOI: 10.1093/plphys/kiab168] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 03/07/2021] [Indexed: 05/11/2023]
Abstract
Fatty acid photodecarboxylase (FAP) is one of the few enzymes that require light for their catalytic cycle (photoenzymes). FAP was first identified in the microalga Chlorella variabilis NC64A, and belongs to an algae-specific subgroup of the glucose-methanol-choline oxidoreductase family. While the FAP from C. variabilis and its Chlamydomonas reinhardtii homolog CrFAP have demonstrated in vitro activities, their activities and physiological functions have not been studied in vivo. Furthermore, the conservation of FAP activity beyond green microalgae remains hypothetical. Here, using a C. reinhardtii FAP knockout line (fap), we showed that CrFAP is responsible for the formation of 7-heptadecene, the only hydrocarbon of this alga. We further showed that CrFAP was predominantly membrane-associated and that >90% of 7-heptadecene was recovered in the thylakoid fraction. In the fap mutant, photosynthetic activity was not affected under standard growth conditions, but was reduced after cold acclimation when light intensity varied. A phylogenetic analysis that included sequences from Tara Ocean identified almost 200 putative FAPs and indicated that FAP was acquired early after primary endosymbiosis. Within Bikonta, FAP was retained in secondary photosynthetic endosymbiosis lineages but absent from those that lost the plastid. Characterization of recombinant FAPs from various algal genera (Nannochloropsis, Ectocarpus, Galdieria, Chondrus) provided experimental evidence that FAP photochemical activity was present in red and brown algae, and was not limited to unicellular species. These results thus indicate that FAP was conserved during the evolution of most algal lineages where photosynthesis was retained, and suggest that its function is linked to photosynthetic membranes.
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Affiliation(s)
- Solène L Y Moulin
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- Present address: Stanford University, 279 Campus Dr, Stanford, CA 94305
| | - Audrey Beyly-Adriano
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Stéphan Cuiné
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Stéphanie Blangy
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Bertrand Légeret
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Magali Floriani
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-ENV/SRTE/LECO, Cadarache, 13108 Saint-Paul-Lez-Durance, France
| | - Adrien Burlacot
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- Present address: Howard Hughes Medical Institute, Department of Plant and Microbial Biology, 111 Koshland Hall, University of California, Berkeley, CA 94720-3102, USA
| | - Damien Sorigué
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Poutoum-Palakiyem Samire
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Yonghua Li-Beisson
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
| | - Fred Beisson
- CEA, CNRS, Aix-Marseille University, Institute of Biosciences and Biotechnologies of Aix-Marseille (BIAM), UMR7265, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- Author for communication:
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19
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Thapa N, Chaudhari M, Iannetta AA, White C, Roy K, Newman RH, Hicks LM, Kc DB. A deep learning based approach for prediction of Chlamydomonas reinhardtii phosphorylation sites. Sci Rep 2021; 11:12550. [PMID: 34131195 PMCID: PMC8206365 DOI: 10.1038/s41598-021-91840-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/28/2021] [Indexed: 11/23/2022] Open
Abstract
Protein phosphorylation, which is one of the most important post-translational modifications (PTMs), is involved in regulating myriad cellular processes. Herein, we present a novel deep learning based approach for organism-specific protein phosphorylation site prediction in Chlamydomonas reinhardtii, a model algal phototroph. An ensemble model combining convolutional neural networks and long short-term memory (LSTM) achieves the best performance in predicting phosphorylation sites in C. reinhardtii. Deemed Chlamy-EnPhosSite, the measured best AUC and MCC are 0.90 and 0.64 respectively for a combined dataset of serine (S) and threonine (T) in independent testing higher than those measures for other predictors. When applied to the entire C. reinhardtii proteome (totaling 1,809,304 S and T sites), Chlamy-EnPhosSite yielded 499,411 phosphorylated sites with a cut-off value of 0.5 and 237,949 phosphorylated sites with a cut-off value of 0.7. These predictions were compared to an experimental dataset of phosphosites identified by liquid chromatography-tandem mass spectrometry (LC–MS/MS) in a blinded study and approximately 89.69% of 2,663 C. reinhardtii S and T phosphorylation sites were successfully predicted by Chlamy-EnPhosSite at a probability cut-off of 0.5 and 76.83% of sites were successfully identified at a more stringent 0.7 cut-off. Interestingly, Chlamy-EnPhosSite also successfully predicted experimentally confirmed phosphorylation sites in a protein sequence (e.g., RPS6 S245) which did not appear in the training dataset, highlighting prediction accuracy and the power of leveraging predictions to identify biologically relevant PTM sites. These results demonstrate that our method represents a robust and complementary technique for high-throughput phosphorylation site prediction in C. reinhardtii. It has potential to serve as a useful tool to the community. Chlamy-EnPhosSite will contribute to the understanding of how protein phosphorylation influences various biological processes in this important model microalga.
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Affiliation(s)
- Niraj Thapa
- Department of Computational Data Science and Engineering, North Carolina A&T State University, Greensboro, NC, USA
| | - Meenal Chaudhari
- Department of Computational Data Science and Engineering, North Carolina A&T State University, Greensboro, NC, USA
| | - Anthony A Iannetta
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Clarence White
- Department of Computational Data Science and Engineering, North Carolina A&T State University, Greensboro, NC, USA
| | - Kaushik Roy
- Department of Computer Science, North Carolina A&T State University, Greensboro, NC, USA
| | - Robert H Newman
- Department of Biology, North Carolina A&T State University, Greensboro, NC, USA
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Dukka B Kc
- Electrical Engineering and Computer Science Department, Wichita State University, Wichita, KS, USA.
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20
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Leyland B, Zarka A, Didi-Cohen S, Boussiba S, Khozin-Goldberg I. High Resolution Proteome of Lipid Droplets Isolated from the Pennate Diatom Phaeodactylum tricornutum (Bacillariophyceae) Strain pt4 provides mechanistic insights into complex intracellular coordination during nitrogen deprivation. JOURNAL OF PHYCOLOGY 2020; 56:1642-1663. [PMID: 32779202 DOI: 10.1111/jpy.13063] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/14/2020] [Accepted: 07/12/2020] [Indexed: 05/08/2023]
Abstract
Lipid droplets (LDs) are an organelle conserved amongst all eukaryotes, consisting of a neutral lipid core surrounded by a polar lipid monolayer. Many species of microalgae accumulate LDs in response to stress conditions, such as nitrogen starvation. Here, we report the isolation and proteomic profiling of LD proteins from the model oleaginous pennate diatom Phaeodactylum tricornutum, strain Pt4 (UTEX 646). We also provide a quantitative description of LD morphological ontogeny, and fatty acid content. Novel cell disruption and LD isolation methods, combined with suspension-trapping and nanoflow liquid chromatography coupled to high resolution mass spectrometry, yielded an unprecedented number of LD proteins. Predictive annotation of the LD proteome suggests a broad assemblage of proteins with diverse functions, including lipid metabolism and vesicle trafficking, as well as ribosomal and proteasomal machinery. These proteins provide mechanistic insights into LD processes, and evidence for interactions between LDs and other organelles. We identify for the first time several key steps in diatom LD-associated triacylglycerol biosynthesis. Bioinformatic analyses of the LD proteome suggests multiple protein targeting mechanisms, including amphipathic helices, post-translational modifications, and translocation machinery. This work corroborates recent findings from other strains of P. tricornutum, other diatoms, and other eukaryotic organisms, suggesting that the fundamental proteins orchestrating LDs are conserved, and represent an ancient component of the eukaryotic endomembrane system. We postulate a comprehensive model of nitrogen starvation-induced diatom LDs on a molecular scale, and provide a wealth of candidates for metabolic engineering, with the potential to eventually customize LD contents.
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Affiliation(s)
- Ben Leyland
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Aliza Zarka
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Shoshana Didi-Cohen
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Sammy Boussiba
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
| | - Inna Khozin-Goldberg
- The Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Be'er Sheva, 84990, Israel
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21
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Fuentes-Ramírez EO, Vázquez-Acevedo M, Cabrera-Orefice A, Guerrero-Castillo S, González-Halphen D. The plastid proteome of the nonphotosynthetic chlorophycean alga Polytomella parva. Microbiol Res 2020; 243:126649. [PMID: 33285428 DOI: 10.1016/j.micres.2020.126649] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/23/2020] [Accepted: 11/13/2020] [Indexed: 11/19/2022]
Abstract
The unicellular, free-living, nonphotosynthetic chlorophycean alga Polytomella parva, closely related to Chlamydomonas reinhardtii and Volvox carteri, contains colorless, starch-storing plastids. The P. parva plastids lack all light-dependent processes but maintain crucial metabolic pathways. The colorless alga also lacks a plastid genome, meaning no transcription or translation should occur inside the organelle. Here, using an algal fraction enriched in plastids as well as publicly available transcriptome data, we provide a morphological and proteomic characterization of the P. parva plastid, ultimately identifying several plastid proteins, both by mass spectrometry and bioinformatic analyses. Data are available via ProteomeXchange with identifier PXD022051. Altogether these results led us to propose a plastid proteome for P. parva, i.e., a set of proteins that participate in carbohydrate metabolism; in the synthesis and degradation of starch, amino acids and lipids; in the biosynthesis of terpenoids and tetrapyrroles; in solute transport and protein translocation; and in redox homeostasis. This is the first detailed plastid proteome from a unicellular, free-living colorless alga.
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Affiliation(s)
- Emma O Fuentes-Ramírez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, CDMX, Mexico.
| | - Miriam Vázquez-Acevedo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, CDMX, Mexico.
| | - Alfredo Cabrera-Orefice
- Radboud Institute for Molecular Life Sciences, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525, GA, Nijmegen, the Netherlands.
| | - Sergio Guerrero-Castillo
- Radboud Institute for Molecular Life Sciences, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525, GA, Nijmegen, the Netherlands; University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, CDMX, Mexico.
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Meyer MT, Itakura AK, Patena W, Wang L, He S, Emrich-Mills T, Lau CS, Yates G, Mackinder LCM, Jonikas MC. Assembly of the algal CO 2-fixing organelle, the pyrenoid, is guided by a Rubisco-binding motif. SCIENCE ADVANCES 2020; 6:eabd2408. [PMID: 33177094 PMCID: PMC7673724 DOI: 10.1126/sciadv.abd2408] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/25/2020] [Indexed: 05/05/2023]
Abstract
Approximately one-third of the Earth's photosynthetic CO2 assimilation occurs in a pyrenoid, an organelle containing the CO2-fixing enzyme Rubisco. How constituent proteins are recruited to the pyrenoid and how the organelle's subcompartments-membrane tubules, a surrounding phase-separated Rubisco matrix, and a peripheral starch sheath-are held together is unknown. Using the model alga Chlamydomonas reinhardtii, we found that pyrenoid proteins share a sequence motif. We show that the motif is necessary and sufficient to target proteins to the pyrenoid and that the motif binds to Rubisco, suggesting a mechanism for targeting. The presence of the Rubisco-binding motif on proteins that localize to the tubules and on proteins that localize to the matrix-starch sheath interface suggests that the motif holds the pyrenoid's three subcompartments together. Our findings advance our understanding of pyrenoid biogenesis and illustrate how a single protein motif can underlie the architecture of a complex multilayered phase-separated organelle.
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Affiliation(s)
- Moritz T Meyer
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Alan K Itakura
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Weronika Patena
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Lianyong Wang
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Shan He
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | | - Chun S Lau
- Department of Biology, University of York, York YO10 5DD, UK
| | - Gary Yates
- Department of Biology, University of York, York YO10 5DD, UK
| | | | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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23
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Xu C, Fan J, Shanklin J. Metabolic and functional connections between cytoplasmic and chloroplast triacylglycerol storage. Prog Lipid Res 2020; 80:101069. [DOI: 10.1016/j.plipres.2020.101069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/23/2020] [Accepted: 10/24/2020] [Indexed: 12/14/2022]
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Abstract
Lutein is particularly known to help maintain normal visual function by absorbing and attenuating the blue light that strikes the retina in our eyes. The effect of overexposure to blue light on our eyes due to the excessive use of electronic devices is becoming an issue of modern society due to insufficient dietary lutein consumption through our normal diet. There has, therefore, been an increasing demand for lutein-containing dietary supplements and also in the food industry for lutein supplementation in bakery products, infant formulas, dairy products, carbonated drinks, energy drinks, and juice concentrates. Although synthetic carotenoid dominates the market, there is a need for environmentally sustainable carotenoids including lutein production pathways to match increasing consumer demand for natural alternatives. Currently, marigold flowers are the predominant natural source of lutein. Microalgae can be a competitive sustainable alternative, which have higher growth rates and do not require arable land and/or a growth season. Currently, there is no commercial production of lutein from microalgae, even though astaxanthin and β-carotene are commercially produced from specific microalgal strains. This review discusses the potential microalgae strains for commercial lutein production, appropriate cultivation strategies, and the challenges associated with realising a commercial market share.
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Falarz LJ, Xu Y, Caldo KMP, Garroway CJ, Singer SD, Chen G. Characterization of the diversification of phospholipid:diacylglycerol acyltransferases in the green lineage. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:2025-2038. [PMID: 32538516 DOI: 10.1111/tpj.14880] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 05/03/2023]
Abstract
Triacylglycerols have important physiological roles in photosynthetic organisms, and are widely used as food, feed and industrial materials in our daily life. Phospholipid:diacylglycerol acyltransferase (PDAT) is the pivotal enzyme catalyzing the acyl-CoA-independent biosynthesis of triacylglycerols, which is unique in plants, algae and fungi, but not in animals, and has essential functions in plant and algal growth, development and stress responses. Currently, this enzyme has yet to be examined in an evolutionary context at the level of the green lineage. Some fundamental questions remain unanswered, such as how PDATs evolved in photosynthetic organisms and whether the evolution of terrestrial plant PDATs from a lineage of charophyte green algae diverges in enzyme function. As such, we used molecular evolutionary analysis and biochemical assays to address these questions. Our results indicated that PDAT underwent divergent evolution in the green lineage: PDATs exist in a wide range of plants and algae, but not in cyanobacteria. Although PDATs exhibit the conservation of several features, phylogenetic and selection-pressure analyses revealed that overall they evolved to be highly divergent, driven by different selection constraints. Positive selection, as one major driving force, may have resulted in enzymes with a higher functional importance in land plants than green algae. Further structural and mutagenesis analyses demonstrated that some amino acid sites under positive selection are critically important to PDAT structure and function, and may be central in lecithin:cholesterol acyltransferase family enzymes in general.
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Affiliation(s)
- Lucas J Falarz
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Colin J Garroway
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Stacy D Singer
- Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, AB, T1J 4B1, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada
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26
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Puzanskiy RK, Romanyuk DA, Kirpichnikova AA, Shishova MF. Alteration in the Expression of Genes Encoding Primary Metabolism Enzymes and Plastid Transporters during the Culture Growth of Chlamydomonas reinhardtii. Mol Biol 2020. [DOI: 10.1134/s0026893320040147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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27
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de Vries J, de Vries S, Curtis BA, Zhou H, Penny S, Feussner K, Pinto DM, Steinert M, Cohen AM, von Schwartzenberg K, Archibald JM. Heat stress response in the closest algal relatives of land plants reveals conserved stress signaling circuits. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1025-1048. [PMID: 32333477 DOI: 10.1111/tpj.14782] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/28/2020] [Accepted: 04/08/2020] [Indexed: 05/20/2023]
Abstract
All land plants (embryophytes) share a common ancestor that likely evolved from a filamentous freshwater alga. Elucidating the transition from algae to embryophytes - and the eventual conquering of Earth's surface - is one of the most fundamental questions in plant evolutionary biology. Here, we investigated one of the organismal properties that might have enabled this transition: resistance to drastic temperature shifts. We explored the effect of heat stress in Mougeotia and Spirogyra, two representatives of Zygnematophyceae - the closest known algal sister lineage to land plants. Heat stress induced pronounced phenotypic alterations in their plastids, and high-performance liquid chromatography-tandem mass spectroscopy-based profiling of 565 transitions for the analysis of main central metabolites revealed significant shifts in 43 compounds. We also analyzed the global differential gene expression responses triggered by heat, generating 92.8 Gbp of sequence data and assembling a combined set of 8905 well-expressed genes. Each organism had its own distinct gene expression profile; less than one-half of their shared genes showed concordant gene expression trends. We nevertheless detected common signature responses to heat such as elevated transcript levels for molecular chaperones, thylakoid components, and - corroborating our metabolomic data - amino acid metabolism. We also uncovered the heat-stress responsiveness of genes for phosphorelay-based signal transduction that links environmental cues, calcium signatures and plastid biology. Our data allow us to infer the molecular heat stress response that the earliest land plants might have used when facing the rapidly shifting temperature conditions of the terrestrial habitat.
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Affiliation(s)
- Jan de Vries
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, NS, B3H 4R2, Canada
- Institute of Microbiology, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
- Department of Applied Bioinformatics, Institute for Microbiology and Genetics, University of Goettingen, Goldschmidtstr. 1, 37077, Goettingen, Germany
- Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077, Goettingen, Germany
| | - Sophie de Vries
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, NS, B3H 4R2, Canada
- Institute of Population Genetics, Heinrich-Heine University Duesseldorf, Universitätsstr. 1, 40225, Duesseldorf, Germany
| | - Bruce A Curtis
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, NS, B3H 4R2, Canada
| | - Hong Zhou
- Microalgae and Zygnematophyceae Collection Hamburg (MZCH) and Aquatic Ecophysiology and Phycology, Institute of Plant Science and Microbiology, Universität Hamburg, 22609, Hamburg, Germany
| | - Susanne Penny
- National Research Council, Human Health Therapeutics, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada
| | - Kirstin Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, Justus-von-Liebig-Weg 11, 37077, Goettingen, Germany
- Service Unit for Metabolomics and Lipidomics, Goettingen Center for Molecular Biosciences (GZMB), 37077, Goettingen, Germany
| | - Devanand M Pinto
- National Research Council, Human Health Therapeutics, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada
- Department of Chemistry, Dalhousie University, 6274 Coburg Rd, Halifax, NS, B3H 4R2, Canada
| | - Michael Steinert
- Institute of Microbiology, Technische Universität Braunschweig, Spielmannstr. 7, 38106, Braunschweig, Germany
| | - Alejandro M Cohen
- Biological Spectrometry Core Facility, Life Sciences Research Institute, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Klaus von Schwartzenberg
- Microalgae and Zygnematophyceae Collection Hamburg (MZCH) and Aquatic Ecophysiology and Phycology, Institute of Plant Science and Microbiology, Universität Hamburg, 22609, Hamburg, Germany
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, NS, B3H 4R2, Canada
- Canadian Institute for Advanced Research, 661 University Ave, Suite 505, Toronto, ON, M5G 1M1, Canada
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28
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Bjerkelund Røkke G, Hohmann-Marriott MF, Almaas E. An adjustable algal chloroplast plug-and-play model for genome-scale metabolic models. PLoS One 2020; 15:e0229408. [PMID: 32092117 PMCID: PMC7039451 DOI: 10.1371/journal.pone.0229408] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/05/2020] [Indexed: 01/25/2023] Open
Abstract
The chloroplast is a central part of plant cells, as this is the organelle where the photosynthesis, fixation of inorganic carbon, and other key functions related to fatty acid synthesis and amino acid synthesis occur. Since this organelle should be an integral part of any genome-scale metabolic model for a microalgae or a higher plant, it is of great interest to generate a detailed and standardized chloroplast model. Additionally, we see the need for a novel type of sub-model template, or organelle model, which could be incorporated into a larger, less specific genome-scale metabolic model, while allowing for minor differences between chloroplast-containing organisms. The result of this work is the very first standardized chloroplast model, iGR774, consisting of 788 reactions, 764 metabolites, and 774 genes. The model is currently able to run in three different modes, mimicking the chloroplast metabolism of three photosynthetic microalgae-Nannochloropsis gaditana, Chlamydomonas reinhardtii and Phaeodactylum tricornutum. In addition to developing the chloroplast metabolic network reconstruction, we have developed multiple software tools for working with this novel type of sub-model in the COBRA Toolbox for MATLAB, including tools for connecting the chloroplast model to a genome-scale metabolic reconstruction in need of a chloroplast, for switching the model between running in different organism modes, and for expanding it by introducing more reactions either related to one of the current organisms included in the model, or to a new organism.
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Affiliation(s)
- Gunvor Bjerkelund Røkke
- Department of Biotechnology and Food Science, The Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Eivind Almaas
- Department of Biotechnology and Food Science, The Norwegian University of Science and Technology, Trondheim, Norway
- K. G. Jebsen Center for Genetic Epidemiology, The Norwegian University of Science and Technology, Trondheim, Norway
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29
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Novák Vanclová AMG, Zoltner M, Kelly S, Soukal P, Záhonová K, Füssy Z, Ebenezer TE, Lacová Dobáková E, Eliáš M, Lukeš J, Field MC, Hampl V. Metabolic quirks and the colourful history of the Euglena gracilis secondary plastid. THE NEW PHYTOLOGIST 2020; 225:1578-1592. [PMID: 31580486 DOI: 10.1111/nph.16237] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/25/2019] [Indexed: 05/20/2023]
Abstract
Euglena spp. are phototrophic flagellates with considerable ecological presence and impact. Euglena gracilis harbours secondary green plastids, but an incompletely characterised proteome precludes accurate understanding of both plastid function and evolutionary history. Using subcellular fractionation, an improved sequence database and MS we determined the composition, evolutionary relationships and hence predicted functions of the E. gracilis plastid proteome. We confidently identified 1345 distinct plastid protein groups and found that at least 100 proteins represent horizontal acquisitions from organisms other than green algae or prokaryotes. Metabolic reconstruction confirmed previously studied/predicted enzymes/pathways and provided evidence for multiple unusual features, including uncoupling of carotenoid and phytol metabolism, a limited role in amino acid metabolism, and dual sets of the SUF pathway for FeS cluster assembly, one of which was acquired by lateral gene transfer from Chlamydiae. Plastid paralogues of trafficking-associated proteins potentially mediating fusion of transport vesicles with the outermost plastid membrane were identified, together with derlin-related proteins, potential translocases across the middle membrane, and an extremely simplified TIC complex. The Euglena plastid, as the product of many genomes, combines novel and conserved features of metabolism and transport.
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Affiliation(s)
| | - Martin Zoltner
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Steven Kelly
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - Petr Soukal
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
| | - Kristína Záhonová
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
- Faculty of Science, University of Ostrava, Ostrava, 710 00, Czechia
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - Zoltán Füssy
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - ThankGod E Ebenezer
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Eva Lacová Dobáková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - Marek Eliáš
- Faculty of Science, University of Ostrava, Ostrava, 710 00, Czechia
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
- Faculty of Science, University of South Bohemia, České Budějovice, 370 05, Czechia
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, 370 05, Czechia
| | - Vladimír Hampl
- Faculty of Science, Charles University, BIOCEV, Vestec, 252 50, Czechia
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30
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Kayama M, Maciszewski K, Yabuki A, Miyashita H, Karnkowska A, Kamikawa R. Highly Reduced Plastid Genomes of the Non-photosynthetic Dictyochophyceans Pteridomonas spp. (Ochrophyta, SAR) Are Retained for tRNA-Glu-Based Organellar Heme Biosynthesis. FRONTIERS IN PLANT SCIENCE 2020; 11:602455. [PMID: 33329672 PMCID: PMC7728698 DOI: 10.3389/fpls.2020.602455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/03/2020] [Indexed: 05/05/2023]
Abstract
Organisms that have lost their photosynthetic capabilities are present in a variety of eukaryotic lineages, such as plants and disparate algal groups. Most of such non-photosynthetic eukaryotes still carry plastids, as these organelles retain essential biological functions. Most non-photosynthetic plastids possess genomes with varied protein-coding contents. Such remnant plastids are known to be present in the non-photosynthetic, bacteriovorous alga Pteridomonas danica (Dictyochophyceae, Ochrophyta), which, regardless of its obligatory heterotrophic lifestyle, has been reported to retain the typically plastid-encoded gene for ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit (rbcL). The presence of rbcL without photosynthetic activity suggests that investigating the function of plastids in Pteridomonas spp. would likely bring unique insights into understanding the reductive evolution of plastids, their genomes, and plastid functions retained after the loss of photosynthesis. In this study, we demonstrate that two newly established strains of the non-photosynthetic genus Pteridomonas possess highly reduced plastid genomes lacking rbcL gene, in contrast to the previous report. Interestingly, we discovered that all plastid-encoded proteins in Pteridomonas spp. are involved only in housekeeping processes (e.g., transcription, translation and protein degradation), indicating that all metabolite synthesis pathways in their plastids are supported fully by nuclear genome-encoded proteins. Moreover, through an in-depth survey of the available transcriptomic data of another strain of the genus, we detected no candidate sequences for nuclear-encoded, plastid-directed Fe-S cluster assembly pathway proteins, suggesting complete loss of this pathway in the organelle, despite its widespread conservation in non-photosynthetic plastids. Instead, the transcriptome contains plastid-targeted components of heme biosynthesis, glycolysis, and pentose phosphate pathways. The retention of the plastid genomes in Pteridomonas spp. is not explained by the Suf-mediated constraint against loss of plastid genomes, previously proposed for Alveolates, as they lack Suf genes. Bearing all these findings in mind, we propose the hypothesis that plastid DNA is retained in Pteridomonas spp. for the purpose of providing glutamyl-tRNA, encoded by trnE gene, as a substrate for the heme biosynthesis pathway.
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Affiliation(s)
- Motoki Kayama
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Kacper Maciszewski
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Hideaki Miyashita
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Anna Karnkowska
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
- *Correspondence: Anna Karnkowska,
| | - Ryoma Kamikawa
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- Ryoma Kamikawa,
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Metabolic Innovations Underpinning the Origin and Diversification of the Diatom Chloroplast. Biomolecules 2019; 9:biom9080322. [PMID: 31366180 PMCID: PMC6723447 DOI: 10.3390/biom9080322] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 12/13/2022] Open
Abstract
Of all the eukaryotic algal groups, diatoms make the most substantial contributions to photosynthesis in the contemporary ocean. Understanding the biological innovations that have occurred in the diatom chloroplast may provide us with explanations to the ecological success of this lineage and clues as to how best to exploit the biology of these organisms for biotechnology. In this paper, we use multi-species transcriptome datasets to compare chloroplast metabolism pathways in diatoms to other algal lineages. We identify possible diatom-specific innovations in chloroplast metabolism, including the completion of tocopherol synthesis via a chloroplast-targeted tocopherol cyclase, a complete chloroplast ornithine cycle, and chloroplast-targeted proteins involved in iron acquisition and CO2 concentration not shared between diatoms and their closest relatives in the stramenopiles. We additionally present a detailed investigation of the chloroplast metabolism of the oil-producing diatom Fistulifera solaris, which is of industrial interest for biofuel production. These include modified amino acid and pyruvate hub metabolism that might enhance acetyl-coA production for chloroplast lipid biosynthesis and the presence of a chloroplast-localised squalene synthesis pathway unknown in other diatoms. Our data provides valuable insights into the biological adaptations underpinning an ecologically critical lineage, and how chloroplast metabolism can change even at a species level in extant algae.
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32
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Selim KA, Lapina T, Forchhammer K, Ermilova E. Interaction of N-acetyl-l-glutamate kinase with the PII signal transducer in the non-photosynthetic alga Polytomella parva: Co-evolution towards a hetero-oligomeric enzyme. FEBS J 2019; 287:465-482. [PMID: 31287617 PMCID: PMC7027753 DOI: 10.1111/febs.14989] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/17/2019] [Accepted: 07/06/2019] [Indexed: 12/27/2022]
Abstract
During evolution, several algae and plants became heterotrophic and lost photosynthesis; however, in most cases, a nonphotosynthetic plastid was maintained. Among these organisms, the colourless alga Polytomella parva is a special case, as its plastid is devoid of any DNA, but is maintained for specific metabolic tasks carried out by nuclear encoded enzymes. This makes P. parva attractive to study molecular events underlying the transition from autotrophic to heterotrophic lifestyle. Here we characterize metabolic adaptation strategies of P. parva in comparison to the closely related photosynthetic alga Chlamydomonas reinhardtii with a focus on the role of plastid‐localized PII signalling protein. Polytomella parva accumulates significantly higher amounts of most TCA cycle intermediates as well as glutamate, aspartate and arginine, the latter being specific for the colourless plastid. Correlating with the altered metabolite status, the carbon/nitrogen sensory PII signalling protein and its regulatory target N‐acetyl‐l‐glutamate‐kinase (NAGK; the controlling enzyme of arginine biosynthesis) show unique features: They have co‐evolved into a stable hetero‐oligomeric complex, irrespective of effector molecules. The PII signalling protein, so far known as a transiently interacting signalling protein, appears as a permanent subunit of the enzyme NAGK. NAGK requires PII to properly sense the feedback inhibitor arginine, and moreover, PII tunes arginine‐inhibition in response to glutamine. No other PII effector molecules interfere, indicating that the PII‐NAGK system in P. parva has lost the ability to estimate the cellular energy and carbon status but has specialized to provide an entirely glutamine‐dependent arginine feedback control, highlighting the evolutionary plasticity of PII signalling system.
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Affiliation(s)
- Khaled A Selim
- Department of Microbiology/Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard-Karls-Universität Tübingen, Germany
| | - Tatyana Lapina
- Biological Faculty, Saint-Petersburg State University, Russia
| | - Karl Forchhammer
- Department of Microbiology/Organismic Interactions, Interfaculty Institute of Microbiology and Infection Medicine, Eberhard-Karls-Universität Tübingen, Germany
| | - Elena Ermilova
- Biological Faculty, Saint-Petersburg State University, Russia
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Bai Y, Chen T, Happe T, Lu Y, Sawyer A. Iron-sulphur cluster biogenesis via the SUF pathway. Metallomics 2019; 10:1038-1052. [PMID: 30019043 DOI: 10.1039/c8mt00150b] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Iron-sulphur (Fe-S) clusters are versatile cofactors, which are essential for key metabolic processes in cells, such as respiration and photosynthesis, and which may have also played a crucial role in establishing life on Earth. They can be found in almost all living organisms, from unicellular prokaryotes and archaea to multicellular animals and plants, and exist in diverse forms. This review focuses on the most ancient Fe-S cluster assembly system, the sulphur utilization factor (SUF) mechanism, which is crucial in bacteria for cell survival under stress conditions such as oxidation and iron starvation, and which is also present in the chloroplasts of green microalgae and plants, where it is responsible for plastidial Fe-S protein maturation. We explain the SUF Fe-S cluster assembly process, the proteins involved, their regulation and provide evolutionary insights. We specifically focus on examples from Fe-S cluster synthesis in the model organisms Escherichia coli and Arabidopsis thaliana and discuss in an in vivo context the assembly of the [FeFe]-hydrogenase H-cluster from Chlamydomonas reinhardtii.
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Affiliation(s)
- Y Bai
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
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34
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Füssy Z, Faitová T, Oborník M. Subcellular Compartments Interplay for Carbon and Nitrogen Allocation in Chromera velia and Vitrella brassicaformis. Genome Biol Evol 2019; 11:1765-1779. [PMID: 31192348 PMCID: PMC6668581 DOI: 10.1093/gbe/evz123] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2019] [Indexed: 12/20/2022] Open
Abstract
Endosymbioses necessitate functional cooperation of cellular compartments to avoid pathway redundancy and streamline the control of biological processes. To gain insight into the metabolic compartmentation in chromerids, phototrophic relatives to apicomplexan parasites, we prepared a reference set of proteins probably localized to mitochondria, cytosol, and the plastid, taking advantage of available genomic and transcriptomic data. Training of prediction algorithms with the reference set now allows a genome-wide analysis of protein localization in Chromera velia and Vitrella brassicaformis. We confirm that the chromerid plastids house enzymatic pathways needed for their maintenance and photosynthetic activity, but for carbon and nitrogen allocation, metabolite exchange is necessary with the cytosol and mitochondria. This indeed suggests that the regulatory mechanisms operate in the cytosol to control carbon metabolism based on the availability of both light and nutrients. We discuss that this arrangement is largely shared with apicomplexans and dinoflagellates, possibly stemming from a common ancestral metabolic architecture, and supports the mixotrophy of the chromerid algae.
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Affiliation(s)
- Zoltán Füssy
- Faculty of Science, Department of Molecular Biology and Genetics, University of South Bohemia, České Budějovice, Czech Republic
- Department of Evolutionary Protistology, Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
| | - Tereza Faitová
- Faculty of Science, Department of Molecular Biology and Genetics, University of South Bohemia, České Budějovice, Czech Republic
- Department of Evolutionary Protistology, Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
- Faculty of Engineering and Natural Sciences, Department of Computer Science, Johannes Kepler University, Linz, Austria
| | - Miroslav Oborník
- Faculty of Science, Department of Molecular Biology and Genetics, University of South Bohemia, České Budějovice, Czech Republic
- Department of Evolutionary Protistology, Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
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A genome-wide algal mutant library and functional screen identifies genes required for eukaryotic photosynthesis. Nat Genet 2019; 51:627-635. [PMID: 30886426 PMCID: PMC6636631 DOI: 10.1038/s41588-019-0370-6] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 02/08/2019] [Indexed: 12/22/2022]
Abstract
Photosynthetic organisms provide food and energy for nearly all life on Earth, yet half of their protein-coding genes remain uncharacterized1,2. Characterization of these genes could be greatly accelerated by new genetic resources for unicellular organisms. Here, we generated a genome-wide, indexed library of mapped insertion mutants for the unicellular alga Chlamydomonas reinhardtii. The 62,389 mutants in the library, covering 83% of nuclear, protein-coding genes, are available to the community. Each mutant contains unique DNA barcodes, allowing the collection to be screened as a pool. We performed a genome-wide survey of genes required for photosynthesis, which identified 303 candidate genes. Characterization of one of these genes, the conserved predicted phosphatase-encoding gene CPL3, showed it is important for accumulation of multiple photosynthetic protein complexes. Notably, 21 of the 43 highest-confidence genes are novel, opening new opportunities for advances in our understanding of this biogeochemically fundamental process. This library will accelerate the characterization of thousands of genes in algae, plants and animals. Generation of a library of 62,389 mapped insertion mutants for the unicellular alga Chlamydomonas reinhardtii enables screening for genes required for photosynthesis and the identification of 303 candidate genes.
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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Naghshbandi MP, Tabatabaei M, Aghbashlo M, Aftab MN, Iqbal I. Metabolic Engineering of Microalgae for Biofuel Production. Methods Mol Biol 2019; 1980:153-172. [PMID: 30666564 DOI: 10.1007/7651_2018_205] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Microalgae are considered as promising cell factories for the production of various types of biofuels, including bioethanol, biodiesel, and biohydrogen by using carbon dioxide and sunlight. In spite of unique advantages of these microorganisms, the commercialization of microalgal biofuels has been hindered by poor economic features. Metabolic engineering is among the most promising strategies put forth to overcome this challenge. In this chapter, metabolic pathways involved in lipid and hydrogen production by microalgae are reviewed and discussed. Moreover, metabolic and genetic engineering approaches investigated for improving the rate of lipid (as a feedstock for biodiesel production) and biohydrogen synthesis are presented. Finally, genetic engineering tools and approaches employed for engineering microalgal metabolic pathways are elaborated. A thorough step-by-step protocol for reconstructing the metabolic pathway of various microorganisms including microalgae is also presented.
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Affiliation(s)
- Mohammad Pooya Naghshbandi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Meisam Tabatabaei
- Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran. .,Biofuel Research Team (BRTeam), Karaj, Iran.
| | - Mortaza Aghbashlo
- Department of Mechanical Engineering of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
| | - Muhammad Nauman Aftab
- Institute of Industrial Biotechnology, Government College University, Lahore, Pakistan
| | - Irfana Iqbal
- Department of Zoology, Lahore College for Women University, Lahore, Pakistan
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Marchand J, Heydarizadeh P, Schoefs B, Spetea C. Ion and metabolite transport in the chloroplast of algae: lessons from land plants. Cell Mol Life Sci 2018; 75:2153-2176. [PMID: 29541792 PMCID: PMC5948301 DOI: 10.1007/s00018-018-2793-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 03/01/2018] [Accepted: 03/07/2018] [Indexed: 12/28/2022]
Abstract
Chloroplasts are endosymbiotic organelles and play crucial roles in energy supply and metabolism of eukaryotic photosynthetic organisms (algae and land plants). They harbor channels and transporters in the envelope and thylakoid membranes, mediating the exchange of ions and metabolites with the cytosol and the chloroplast stroma and between the different chloroplast subcompartments. In secondarily evolved algae, three or four envelope membranes surround the chloroplast, making more complex the exchange of ions and metabolites. Despite the importance of transport proteins for the optimal functioning of the chloroplast in algae, and that many land plant homologues have been predicted, experimental evidence and molecular characterization are missing in most cases. Here, we provide an overview of the current knowledge about ion and metabolite transport in the chloroplast from algae. The main aspects reviewed are localization and activity of the transport proteins from algae and/or of homologues from other organisms including land plants. Most chloroplast transporters were identified in the green alga Chlamydomonas reinhardtii, reside in the envelope and participate in carbon acquisition and metabolism. Only a few identified algal transporters are located in the thylakoid membrane and play role in ion transport. The presence of genes for putative transporters in green algae, red algae, diatoms, glaucophytes and cryptophytes is discussed, and roles in the chloroplast are suggested. A deep knowledge in this field is required because algae represent a potential source of biomass and valuable metabolites for industry, medicine and agriculture.
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Affiliation(s)
- Justine Marchand
- Metabolism, Bioengineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML, FR 3473 CNRS, Le Mans University, 72000, Le Mans, France
| | - Parisa Heydarizadeh
- Metabolism, Bioengineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML, FR 3473 CNRS, Le Mans University, 72000, Le Mans, France
| | - Benoît Schoefs
- Metabolism, Bioengineering of Microalgal Molecules and Applications (MIMMA), Mer Molécules Santé, IUML, FR 3473 CNRS, Le Mans University, 72000, Le Mans, France.
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, 40530, Göteborg, Sweden.
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Wittkopp TM, Saroussi S, Yang W, Johnson X, Kim RG, Heinnickel ML, Russell JJ, Phuthong W, Dent RM, Broeckling CD, Peers G, Lohr M, Wollman FA, Niyogi KK, Grossman AR. GreenCut protein CPLD49 of Chlamydomonas reinhardtii associates with thylakoid membranes and is required for cytochrome b 6 f complex accumulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:1023-1037. [PMID: 29602195 DOI: 10.1111/tpj.13915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/23/2018] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
The GreenCut encompasses a suite of nucleus-encoded proteins with orthologs among green lineage organisms (plants, green algae), but that are absent or poorly conserved in non-photosynthetic/heterotrophic organisms. In Chlamydomonas reinhardtii, CPLD49 (Conserved in Plant Lineage and Diatoms49) is an uncharacterized GreenCut protein that is critical for maintaining normal photosynthetic function. We demonstrate that a cpld49 mutant has impaired photoautotrophic growth under high-light conditions. The mutant exhibits a nearly 90% reduction in the level of the cytochrome b6 f complex (Cytb6 f), which impacts linear and cyclic electron transport, but does not compromise the ability of the strain to perform state transitions. Furthermore, CPLD49 strongly associates with thylakoid membranes where it may be part of a membrane protein complex with another GreenCut protein, CPLD38; a mutant null for CPLD38 also impacts Cytb6 f complex accumulation. We investigated several potential functions of CPLD49, with some suggested by protein homology. Our findings are congruent with the hypothesis that CPLD38 and CPLD49 are part of a novel thylakoid membrane complex that primarily modulates accumulation, but also impacts the activity of the Cytb6 f complex. Based on motifs of CPLD49 and the activities of other CPLD49-like proteins, we suggest a role for this putative dehydrogenase in the synthesis of a lipophilic thylakoid membrane molecule or cofactor that influences the assembly and activity of Cytb6 f.
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Affiliation(s)
- Tyler M Wittkopp
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Shai Saroussi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Wenqiang Yang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Xenie Johnson
- Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint Paul lez Durance, France
| | - Rick G Kim
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Mark L Heinnickel
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - James J Russell
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Witchukorn Phuthong
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Rachel M Dent
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Corey D Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, CO, 80523, USA
| | - Graham Peers
- Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Martin Lohr
- Institut für Molekulare Physiologie - Pflanzenbiochemie, Johannes Gutenberg-Universität, 55099, Mainz, Germany
| | | | - Krishna K Niyogi
- Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720-3102, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
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McKie-Krisberg ZM, Laurens LM, Huang A, Polle JE. Comparative energetics of carbon storage molecules in green algae. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.01.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Füssy Z, Oborník M. Complex Endosymbioses I: From Primary to Complex Plastids, Multiple Independent Events. Methods Mol Biol 2018; 1829:17-35. [PMID: 29987712 DOI: 10.1007/978-1-4939-8654-5_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A substantial portion of eukaryote diversity consists of algae with complex plastids, i.e., plastids originating from eukaryote-to-eukaryote endosymbioses. These plastids are characteristic by a deviating number of envelope membranes (higher than two), and sometimes a remnant nucleus of the endosymbiont alga, termed the nucleomorph, is present. Complex plastid-bearing algae are therefore much like living matryoshka dolls, eukaryotes within eukaryotes. In comparison, primary plastids of Archaeplastida (plants, green algae, red algae, and glaucophytes) arose upon a single endosymbiosis event with a cyanobacterium and are surrounded by two membranes. Complex plastids were acquired several times by unrelated groups nested within eukaryotic heterotrophs, suggesting complex plastids are somewhat easier to obtain than primary plastids. This is consistent with the existence of higher-order and serial endosymbioses, i.e., engulfment of complex plastid-bearing algae by (tertiary) eukaryotic hosts and functional plastid replacements, respectively. Plastid endosymbiosis is typical by a massive transfer of genetic material from the endosymbiont to the host nucleus and metabolic rearrangements related to the trophic switch to phototrophy; this is necessary to establish metabolic integration of the plastid and control over its division. Although photosynthesis is the main advantage of plastid acquisition, algae that lost photosynthesis often maintain complex plastids, suggesting their roles beyond photosynthesis. This chapter summarizes basic knowledge on acquisition and functions of complex plastid.
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Affiliation(s)
- Zoltán Füssy
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, České Budějovice, 37005, Czech Republic
- University of South Bohemia, Faculty of Science, Branišovská 31, 37005, České Budějovice, Czech Republic
| | - Miroslav Oborník
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, České Budějovice, 37005, Czech Republic.
- University of South Bohemia, Faculty of Science, Branišovská 31, 37005, České Budějovice, Czech Republic.
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Reductive evolution of chloroplasts in non-photosynthetic plants, algae and protists. Curr Genet 2017; 64:365-387. [DOI: 10.1007/s00294-017-0761-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/22/2017] [Accepted: 10/04/2017] [Indexed: 11/24/2022]
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Büchel C, Wilhelm C, Wagner V, Mittag M. Functional proteomics of light-harvesting complex proteins under varying light-conditions in diatoms. JOURNAL OF PLANT PHYSIOLOGY 2017; 217:38-43. [PMID: 28709708 DOI: 10.1016/j.jplph.2017.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/08/2017] [Accepted: 06/09/2017] [Indexed: 06/07/2023]
Abstract
Comparative proteome analysis of subcellular compartments like thylakoid membranes and their associated supercomplexes can deliver important in-vivo information on the molecular basis of physiological functions which go far beyond to that what can be learnt from transcriptional-based gene expression studies. For instance, the finding that light intensity influences mainly the relative stoichiometry of subunits could be obtained only by high resolution proteome analysis. The high sensitivity of LC-ESI-MS/MS based proteome analysis allows the determination of proteins in very small subfractions along with their non-labeled semi quantitative analysis. This provides insights in the protein-protein interactions of supercomplexes that are the operative units in intact cells. Here, we have focused on functional proteome approaches for the identification of microalgal light-harvesting complex proteins in chloroplasts and the eyespot in general and in detail for those of diatoms that are exposed to varying light conditions.
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Affiliation(s)
- Claudia Büchel
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Christian Wilhelm
- Institute of Biology, Department of Plant Physiology, University of Leipzig, 04103 Leipzig, Germany
| | - Volker Wagner
- Institute of General Botany and Plant Physiology, Friedrich Schiller University, 07743 Jena, Germany
| | - Maria Mittag
- Institute of General Botany and Plant Physiology, Friedrich Schiller University, 07743 Jena, Germany.
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Sawyer A, Bai Y, Lu Y, Hemschemeier A, Happe T. Compartmentalisation of [FeFe]-hydrogenase maturation in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:1134-1143. [PMID: 28295776 DOI: 10.1111/tpj.13535] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/01/2017] [Accepted: 03/06/2017] [Indexed: 06/06/2023]
Abstract
Molecular hydrogen (H2 ) can be produced in green microalgae by [FeFe]-hydrogenases as a direct product of photosynthesis. The Chlamydomonas reinhardtii hydrogenase HYDA1 contains a catalytic site comprising a classic [4Fe4S] cluster linked to a unique 2Fe sub-cluster. From in vitro studies it appears that the [4Fe4S] cluster is incorporated first by the housekeeping FeS cluster assembly machinery, followed by the 2Fe sub-cluster, whose biosynthesis requires the specific maturases HYDEF and HYDG. To investigate the maturation process in vivo, we expressed HYDA1 from the C. reinhardtii chloroplast and nuclear genomes (with and without a chloroplast transit peptide) in a hydrogenase-deficient mutant strain, and examined the cellular enzymatic hydrogenase activity, as well as in vivo H2 production. The transformants expressing HYDA1 from the chloroplast genome displayed levels of H2 production comparable to the wild type, as did the transformants expressing full-length HYDA1 from the nuclear genome. In contrast, cells equipped with cytoplasm-targeted HYDA1 produced inactive enzyme, which could only be activated in vitro after reconstitution of the [4Fe4S] cluster. This indicates that the HYDA1 FeS cluster can only be built by the chloroplastic FeS cluster assembly machinery. Further, the expression of a bacterial hydrogenase gene, CPI, from the C. reinhardtii chloroplast genome resulted in H2 -producing strains, demonstrating that a hydrogenase with a very different structure can fulfil the role of HYDA1 in vivo and that overexpression of foreign hydrogenases in C. reinhardtii is possible. All chloroplast transformants were stable and no toxic effects were seen from HYDA1 or CPI expression.
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Affiliation(s)
- Anne Sawyer
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Yu Bai
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yinghua Lu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Anja Hemschemeier
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
| | - Thomas Happe
- AG Photobiotechnologie, Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie und Biotechnologie, Ruhr-Universität Bochum, 44801, Bochum, Germany
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Morales-Sánchez D, Kim Y, Terng EL, Peterson L, Cerutti H. A multidomain enzyme, with glycerol-3-phosphate dehydrogenase and phosphatase activities, is involved in a chloroplastic pathway for glycerol synthesis in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:1079-1092. [PMID: 28273364 DOI: 10.1111/tpj.13530] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 02/06/2017] [Accepted: 02/28/2017] [Indexed: 05/20/2023]
Abstract
Understanding the unique features of algal metabolism may be necessary to realize the full potential of algae as feedstock for the production of biofuels and biomaterials. Under nitrogen deprivation, the green alga C. reinhardtii showed substantial triacylglycerol (TAG) accumulation and up-regulation of a gene, GPD2, encoding a multidomain enzyme with a putative phosphoserine phosphatase (PSP) motif fused to glycerol-3-phosphate dehydrogenase (GPD) domains. Canonical GPD enzymes catalyze the synthesis of glycerol-3-phosphate (G3P) by reduction of dihydroxyacetone phosphate (DHAP). G3P forms the backbone of TAGs and membrane glycerolipids and it can be dephosphorylated to yield glycerol, an osmotic stabilizer and compatible solute under hypertonic stress. Recombinant Chlamydomonas GPD2 showed both reductase and phosphatase activities in vitro and it can work as a bifunctional enzyme capable of synthesizing glycerol directly from DHAP. In addition, GPD2 and a gene encoding glycerol kinase were up-regulated in Chlamydomonas cells exposed to high salinity. RNA-mediated silencing of GPD2 revealed that the multidomain enzyme was required for TAG accumulation under nitrogen deprivation and for glycerol synthesis under high salinity. Moreover, a GPD2-mCherry fusion protein was found to localize to the chloroplast, supporting the existence of a GPD2-dependent plastid pathway for the rapid synthesis of glycerol in response to hyperosmotic stress. We hypothesize that the reductase and phosphatase activities of PSP-GPD multidomain enzymes may be modulated by post-translational modifications/mechanisms, allowing them to synthesize primarily G3P or glycerol depending on environmental conditions and/or metabolic demands in algal species of the core Chlorophytes.
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Affiliation(s)
- Daniela Morales-Sánchez
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Yeongho Kim
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Ee Leng Terng
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Laura Peterson
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Heriberto Cerutti
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
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Dynamic metabolic profiling together with transcription analysis reveals salinity-induced starch-to-lipid biosynthesis in alga Chlamydomonas sp. JSC4. Sci Rep 2017; 7:45471. [PMID: 28374798 PMCID: PMC5379629 DOI: 10.1038/srep45471] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 02/27/2017] [Indexed: 12/24/2022] Open
Abstract
Biodiesel production using microalgae would play a pivotal role in satisfying future global energy demands. Understanding of lipid metabolism in microalgae is important to isolate oleaginous strain capable of overproducing lipids. It has been reported that reducing starch biosynthesis can enhance lipid accumulation. However, the metabolic mechanism controlling carbon partitioning from starch to lipids in microalgae remains unclear, thus complicating the genetic engineering of algal strains. We here used “dynamic” metabolic profiling and essential transcription analysis of the oleaginous green alga Chlamydomonas sp. JSC4 for the first time to demonstrate the switching mechanisms from starch to lipid synthesis using salinity as a regulator, and identified the metabolic rate-limiting step for enhancing lipid accumulation (e.g., pyruvate-to-acetyl-CoA). These results, showing salinity-induced starch-to-lipid biosynthesis, will help increase our understanding of dynamic carbon partitioning in oleaginous microalgae. Moreover, we successfully determined the changes of several key lipid-synthesis-related genes (e.g., acetyl-CoA carboxylase, pyruvate decarboxylase, acetaldehyde dehydrogenase, acetyl-CoA synthetase and pyruvate ferredoxin oxidoreductase) and starch-degradation related genes (e.g., starch phosphorylases), which could provide a breakthrough in the marine microalgal production of biodiesel.
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Bagnato C, Prados MB, Franchini GR, Scaglia N, Miranda SE, Beligni MV. Analysis of triglyceride synthesis unveils a green algal soluble diacylglycerol acyltransferase and provides clues to potential enzymatic components of the chloroplast pathway. BMC Genomics 2017; 18:223. [PMID: 28274201 PMCID: PMC5343412 DOI: 10.1186/s12864-017-3602-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 02/24/2017] [Indexed: 12/26/2022] Open
Abstract
Background Microalgal triglyceride (TAG) synthesis has attracted considerable attention. Particular emphasis has been put towards characterizing the algal homologs of the canonical rate-limiting enzymes, diacylglycerol acyltransferase (DGAT) and phospholipid:diacylglycerol acyltransferase (PDAT). Less work has been done to analyze homologs from a phylogenetic perspective. In this work, we used HMMER iterative profiling and phylogenetic and functional analyses to determine the number and sequence characteristics of algal DGAT and PDAT, as well as related sequences that constitute their corresponding superfamilies. We included most algae with available genomes, as well as representative eukaryotic and prokaryotic species. Results Amongst our main findings, we identified a novel clade of DGAT1-like proteins exclusive to red algae and glaucophyta and a previously uncharacterized subclade of DGAT2 proteins with an unusual number of transmembrane segments. Our analysis also revealed the existence of a novel DGAT exclusive to green algae with moderate similarity to plant soluble DGAT3. The DGAT3 clade shares a most recent ancestor with a group of uncharacterized proteins from cyanobacteria. Subcellular targeting prediction suggests that most green algal DGAT3 proteins are imported to the chloroplast, evidencing that the green algal chloroplast might have a soluble pathway for the de novo synthesis of TAGs. Heterologous expression of C. reinhardtii DGAT3 produces an increase in the accumulation of TAG, as evidenced by thin layer chromatography. Conclusions Our analysis contributes to advance in the knowledge of complex superfamilies involved in lipid metabolism and provides clues to possible enzymatic players of chloroplast TAG synthesis. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3602-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Carolina Bagnato
- Instituto de Energía y Desarrollo Sustentable, Comisión Nacional de Energía Atómica, Centro Atómico Bariloche, Av. Bustillo 9500, 8400S. C. de Bariloche, Río Negro, Argentina
| | - María B Prados
- Instituto de Energía y Desarrollo Sustentable, Comisión Nacional de Energía Atómica, Centro Atómico Bariloche, Av. Bustillo 9500, 8400S. C. de Bariloche, Río Negro, Argentina
| | - Gisela R Franchini
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP-CONICET-UNLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120 s/n, 1900, La Plata, Argentina
| | - Natalia Scaglia
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP-CONICET-UNLP), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120 s/n, 1900, La Plata, Argentina
| | - Silvia E Miranda
- Universidad de Buenos Aires. CONICET Instituto de Investigaciones Cardiológicas (ININCA), - Laboratorio de Glico-Inmuno-Biología, Marcelo T. de Alvear 2270, C1122AAJ, Buenos Aires, Argentina
| | - María V Beligni
- Instituto de Investigaciones Biológicas (IIB-CONICET-UNMdP), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1245, 7600, Mar del Plata, Argentina.
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Kang NK, Kim EK, Kim YU, Lee B, Jeong WJ, Jeong BR, Chang YK. Increased lipid production by heterologous expression of AtWRI1 transcription factor in Nannochloropsis salina. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:231. [PMID: 29046718 PMCID: PMC5635583 DOI: 10.1186/s13068-017-0919-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/30/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Genetic engineering of microalgae is necessary to produce economically feasible strains for biofuel production. Current efforts are focused on the manipulation of individual metabolic genes, but the outcomes are not sufficiently stable and/or efficient for large-scale production of biofuels and other materials. Transcription factors (TFs) are emerging as good alternatives for engineering of microalgae, not only to increase production of biomaterials but to enhance stress tolerance. Here, we investigated an AP2 type TF Wrinkled1 in Arabidopsis (AtWRI1) known as a key regulator of lipid biosynthesis in plants, and applied it to industrial microalgae, Nannochloropsis salina. RESULTS We expressed AtWRI1 TF heterologously in N. salina, named NsAtWRI1, in an effort to re-enact its key regulatory function of lipid accumulation. Stable integration AtWRI1 was confirmed by RESDA PCR, and its expression was confirmed by Western blotting using the FLAG tag. Characterizations of transformants revealed that the neutral and total lipid contents were greater in NsAtWRI1 transformants than in WT under both normal and stress conditions from day 8. Especially, total lipid contents were 36.5 and 44.7% higher in NsAtWRI1 2-3 than in WT under normal and osmotic stress condition, respectively. FAME contents of NsAtWRI1 2-3 were also increased compared to WT. As a result, FAME yield of NsAtWRI1 2-3 was increased to 768 mg/L/day, which was 64% higher than that of WT under the normal condition. We identified candidates of AtWRI1-regulated genes by searching for the presence of the AW-box in promoter regions, among which lipid metabolic genes were further analyzed by qRT-PCR. Overall, qRT-PCR results on day 1 indicated that AtWRI1 down-regulated TAGL and DAGK, and up-regulated PPDK, LPL, LPGAT1, and PDH, resulting in enhanced lipid production in NsAtWRI1 transformants from early growth phase. CONCLUSION AtWRI1 TF regulated several genes involved in lipid synthesis in N. salina, resulting in enhancement of neutral lipid and FAME production. These findings suggest that heterologous expression of AtWRI1 TF can be utilized for efficient biofuel production in industrial microalgae.
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Affiliation(s)
- Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Young Uk Kim
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125, Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Won-Joong Jeong
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125, Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Tan KWM, Lee YK. The dilemma for lipid productivity in green microalgae: importance of substrate provision in improving oil yield without sacrificing growth. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:255. [PMID: 27895709 PMCID: PMC5120525 DOI: 10.1186/s13068-016-0671-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/16/2016] [Indexed: 05/02/2023]
Abstract
Rising oil prices and concerns over climate change have resulted in more emphasis on research into renewable biofuels from microalgae. Unlike plants, green microalgae have higher biomass productivity, will not compete with food and agriculture, and do not require fertile land for cultivation. However, microalgae biofuels currently suffer from high capital and operating costs due to low yields and costly extraction methods. Microalgae grown under optimal conditions produce large amounts of biomass but with low neutral lipid content, while microalgae grown in nutrient starvation accumulate high levels of neutral lipids but are slow growing. Producing lipids while maintaining high growth rates is vital for biofuel production because high biomass productivity increases yield per harvest volume while high lipid content decreases the cost of extraction per unit product. Therefore, there is a need for metabolic engineering of microalgae to constitutively produce high amounts of lipids without sacrificing growth. Substrate availability is a rate-limiting step in balancing growth and fatty acid (FA) production because both biomass and FA synthesis pathways compete for the same substrates, namely acetyl-CoA and NADPH. In this review, we discuss the efforts made for improving biofuel production in plants and microorganisms, the challenges faced in achieving lipid productivity, and the important role of precursor supply for FA synthesis. The main focus is placed on the enzymes which catalyzed the reactions supplying acetyl-CoA and NADPH.
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Affiliation(s)
- Kenneth Wei Min Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545 Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545 Singapore
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Current advances in molecular, biochemical, and computational modeling analysis of microalgal triacylglycerol biosynthesis. Biotechnol Adv 2016; 34:1046-1063. [DOI: 10.1016/j.biotechadv.2016.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/08/2016] [Accepted: 06/12/2016] [Indexed: 12/12/2022]
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