Author: "Josselin Lupette" - Searchworks@Jio Institute Digital Library Search Results

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27 results on '"Josselin Lupette"'

1. Phosphatidylinositol-4-phosphate controls autophagosome formation in Arabidopsis thaliana

Author: Rodrigo Enrique Gomez, Clément Chambaud, Josselin Lupette, Julie Castets, Stéphanie Pascal, Lysiane Brocard, Lise Noack, Yvon Jaillais, Jérôme Joubès, and Amélie Bernard
Subjects: Science
Abstract: Autophagosomes are specialized vesicles that target and deliver cargo to the lytic vacuole. Here the authors show that plasma-membrane derived lipid phosphatidylinositol-4-phosphate supports the assembly and expansion of autophagosomes in Arabidopsis
Published: 2022
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2. Stepwise Biogenesis of Subpopulations of Lipid Droplets in Nitrogen Starved Phaeodactylum tricornutum Cells

Author: Antoine Jaussaud, Josselin Lupette, Juliette Salvaing, Juliette Jouhet, Olivier Bastien, Marina Gromova, and Eric Maréchal
Subjects: diatoms, Phaeodactylum, Triacylglycerol, lipid droplet, lipids, Plant culture, SB1-1110
Abstract: Diatoms are unicellular heterokonts, living in oceans and freshwaters, exposed to frequent environmental variations. They have a sophisticated membrane compartmentalization and are bounded by a siliceous cell-wall. Formation of lipid droplets (LDs), filled with triacylglycerol (TAG), is a common response to stress. The proteome of mature-LDs from Phaeodactylum tricornutum highlighted the lack of proteins involved in early-LD formation, TAG biosynthesis or LD-to-LD connections. These features suggest that cytosolic LDs might reach a size limit. We analyzed the dynamics of LD formation in P. tricornutum (Pt1 8.6; CCAP 1055/1) during 7 days of nitrogen starvation, by monitoring TAG by mass spectrometry-based lipidomics, and LD radius using epifluorescence microscopy and pulse field gradient nuclear magnetic resonance. We confirmed that mature LDs reach a maximal size. Based on pulse field gradient nuclear magnetic resonance, we did not detect any LD-LD fusion. Three LD subpopulations were produced, each with a different maximal size, larger-sized LDs (radius 0.675 ± 0.125 µm) being generated first. Mathematical modeling showed how smaller LDs are produced once larger LDs have reached their maximum radius. In a mutant line having larger cells, the maximal size of the first LD subpopulation was higher (0.941 ± 0.169 µm), while the principle of stepwise formation of distinct LD populations was maintained. Results suggest that LD size is determined by available cytosolic space and sensing of an optimal size reached in the previous LD subpopulation. Future perspectives include the unraveling of LD-size control mechanisms upon nitrogen shortage. This study also provides novel prospects for the optimization of oleaginous microalgae for biotechnological applications.
Published: 2020
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3. Features of the Opportunistic Behaviour of the Marine Bacterium Marinobacter algicola in the Microalga Ostreococcus tauri Phycosphere

Author: Jordan Pinto, Raphaël Lami, Marc Krasovec, Régis Grimaud, Laurent Urios, Josselin Lupette, Marie-Line Escande, Frédéric Sanchez, Laurent Intertaglia, Nigel Grimsley, Gwenaël Piganeau, and Sophie Sanchez-Brosseau
Subjects: Marinobacter, bacteria, Ostreococcus, phycosphere, phytoplankton, cocultures, Biology (General), QH301-705.5
Abstract: Although interactions between microalgae and bacteria are observed in both natural environment and the laboratory, the modalities of coexistence of bacteria inside microalgae phycospheres in laboratory cultures are mostly unknown. Here, we focused on well-controlled cultures of the model green picoalga Ostreococcus tauri and the most abundant member of its phycosphere, Marinobacter algicola. The prevalence of M. algicola in O. tauri cultures raises questions about how this bacterium maintains itself under laboratory conditions in the microalga culture. The results showed that M. algicola did not promote O. tauri growth in the absence of vitamin B12 while M. algicola depended on O. tauri to grow in synthetic medium, most likely to obtain organic carbon sources provided by the microalgae. M. algicola grew on a range of lipids, including triacylglycerols that are known to be produced by O. tauri in culture during abiotic stress. Genomic screening revealed the absence of genes of two particular modes of quorum-sensing in Marinobacter genomes which refutes the idea that these bacterial communication systems operate in this genus. To date, the ‘opportunistic’ behaviour of M. algicola in the laboratory is limited to several phytoplanktonic species including Chlorophyta such as O. tauri. This would indicate a preferential occurrence of M. algicola in association with these specific microalgae under optimum laboratory conditions.
Published: 2021
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4. How Lipids Contribute to Autophagosome Biogenesis, a Critical Process in Plant Responses to Stresses

Author: Rodrigo Enrique Gomez, Josselin Lupette, Clément Chambaud, Julie Castets, Amélie Ducloy, Jean-Luc Cacas, Céline Masclaux-Daubresse, and Amélie Bernard
Subjects: autophagy, environmental stresses, lipids, ATG proteins, autophagosomes, ER-stress, Cytology, QH573-671
Abstract: Throughout their life cycle, plants face a tremendous number of environmental and developmental stresses. To respond to these different constraints, they have developed a set of refined intracellular systems including autophagy. This pathway, highly conserved among eukaryotes, is induced by a wide range of biotic and abiotic stresses upon which it mediates the degradation and recycling of cytoplasmic material. Central to autophagy is the formation of highly specialized double membrane vesicles called autophagosomes which select, engulf, and traffic cargo to the lytic vacuole for degradation. The biogenesis of these structures requires a series of membrane remodeling events during which both the quantity and quality of lipids are critical to sustain autophagy activity. This review highlights our knowledge, and raises current questions, regarding the mechanism of autophagy, and its induction and regulation upon environmental stresses with a particular focus on the fundamental contribution of lipids. How autophagy regulates metabolism and the recycling of resources, including lipids, to promote plant acclimation and resistance to stresses is further discussed.
Published: 2021
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5. The Role of Chloroplast Membrane Lipid Metabolism in Plant Environmental Responses

Author: Ron Cook, Josselin Lupette, and Christoph Benning
Subjects: fatty acids, glycerolipids, galactolipids, jasmonate, oxylipin, phospholipids, Cytology, QH573-671
Abstract: Plants are nonmotile life forms that are constantly exposed to changing environmental conditions during the course of their life cycle. Fluctuations in environmental conditions can be drastic during both day–night and seasonal cycles, as well as in the long term as the climate changes. Plants are naturally adapted to face these environmental challenges, and it has become increasingly apparent that membranes and their lipid composition are an important component of this adaptive response. Plants can remodel their membranes to change the abundance of different lipid classes, and they can release fatty acids that give rise to signaling compounds in response to environmental cues. Chloroplasts harbor the photosynthetic apparatus of plants embedded into one of the most extensive membrane systems found in nature. In part one of this review, we focus on changes in chloroplast membrane lipid class composition in response to environmental changes, and in part two, we will detail chloroplast lipid-derived signals.
Published: 2021
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6. Correction: LC-MS/MS versus TLC plus GC methods: Consistency of glycerolipid and fatty acid profiles in microalgae and higher plant cells and effect of a nitrogen starvation.

Author: Juliette Jouhet, Josselin Lupette, Olivier Clerc, Leonardo Magneschi, Mariette Bedhomme, Séverine Collin, Sylvaine Roy, Eric Maréchal, and Fabrice Rébeillé
Subjects: Medicine, Science
Abstract: [This corrects the article DOI: 10.1371/journal.pone.0182423.].
Published: 2018
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7. LC-MS/MS versus TLC plus GC methods: Consistency of glycerolipid and fatty acid profiles in microalgae and higher plant cells and effect of a nitrogen starvation.

Author: Juliette Jouhet, Josselin Lupette, Olivier Clerc, Leonardo Magneschi, Mariette Bedhomme, Séverine Collin, Sylvaine Roy, Eric Maréchal, and Fabrice Rébeillé
Subjects: Medicine, Science
Abstract: Methods to analyze lipidomes have considerably evolved, more and more based on mass spectrometry technics (LC-MS/MS). However, accurate quantifications using these methods require 13C-labeled standards for each lipid, which is not feasible because of the very large number of molecules. Thus, quantifications rely on standard molecules representative of a whole class of lipids, which might lead to false estimations of some molecular species. Here, we determined and compared glycerolipid distributions from three different types of cells, two microalgae (Phaeodactylum tricornutum, Nannochloropsis gaditana) and one higher plant (Arabidopsis thaliana), using either LC-MS/MS or Thin Layer Chromatography coupled with Gas Chromatography (TLC-GC), this last approach relying on the precise quantification of the fatty acids present in each glycerolipid class. Our results showed that the glycerolipid distribution was significantly different depending on the method used. How can one reconcile these two analytical methods? Here we propose that the possible bias with MS data can be circumvented by systematically running in tandem with the sample to be analyzed a lipid extract from a qualified control (QC) of each type of cells, previously analyzed by TLC-GC, and used as an external standard to quantify the MS results. As a case study, we applied this method to compare the impact of a nitrogen deficiency on the three types of cells.
Published: 2017
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8. Marinobacter dominates the bacterial community of the Ostreococcus tauri phycosphere in culture

Author: Josselin Lupette, Raphaël Lami, Marc Krasovec, Nigel Harry Grimsley, Hervé Moreau, Gwenael Piganeau, and Sophie Sanchez-Ferandin
Subjects: Bacteria, Phytoplankton, interactions, Ostreococcus tauri, Marinobacter sp., Picoalgae, Microbiology, QR1-502
Abstract: Microalgal-bacterial interactions are commonly found in marine environments and are well known in diatom cultures maintained in laboratory. These interactions also exert strong effects on bacterial and algal diversity in the oceans. Small green eukaryote algae of the class Mamiellophyceae (Chlorophyta) are ubiquitous and some species, such as Ostreococcus spp., are particularly important in Mediterranean coastal lagoons, and are observed as dominant species during phytoplankton blooms in open sea. Despite this, little is known about the diversity of bacteria that might facilitate or hinder O. tauri growth. We show, using rDNA 16S sequences, that the bacterial community found in O. tauri RCC4221 laboratory cultures is dominated by γ-proteobacteria from the Marinobacter genus, regardless of the growth phase of O. tauri RCC4221, the photoperiod used, or the nutrient conditions (limited in nitrogen or phosphorous) tested. Several strains of M. algicola were detected, all closely related to strains found in association with taxonomically distinct organisms, particularly with dinoflagellates and coccolithophorids. These sequences were more distantly related to M. adhaerens, M. aquaeoli and bacteria usually associated to euglenoids. This is the first time, to our knowledge, that distinct Marinobacter strains have been found to be associated with a green alga in culture.
Published: 2016
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9. Human health benefits of very-long-chain polyunsaturated fatty acids from microalgae

Author: Josselin Lupette and Christoph Benning
Subjects: 0301 basic medicine, Cell signaling, Biodiversity, Very long chain, Photosynthesis, Biochemistry, 03 medical and health sciences, Human health, Fatty Acids, Omega-6, Fatty Acids, Omega-3, Microalgae, Animals, Humans, Oxylipins, Beneficial effects, Inflammation, chemistry.chemical_classification, 030102 biochemistry & molecular biology, General Medicine, Lipid Metabolism, 030104 developmental biology, chemistry, lipids (amino acids, peptides, and proteins), sense organs, human activities, Polyunsaturated fatty acid
Abstract: Microalgae are single-cell, photosynthetic organisms whose biodiversity places them at the forefront of biological producers of high-value molecules including lipids and pigments. Some of these organisms particular are capable of synthesizing n-3 very long chain polyunsaturated fatty acids (VLC-PUFAs), known to have beneficial effects on human health. Indeed, VLC-PUFAs are the precursors of many signaling molecules in humans involved in the complexities of inflammatory processes. This mini-review provides an inventory of knowledge on the synthesis of VLC-PUFAs in microalgae and on the diversity of signaling molecules (prostanoids, leukotrienes, SPMs, EFOX, isoprostanoids) that arise in humans from VLC-PUFAs.
Published: 2020

10. Quantitative proteomic analyses reveal the impact of nitrogen starvation on the proteome of the model diatom Phaeodactylum tricornutum

Author: Josselin Lupette, Marianne Tardif, Sabine Brugière, Yohann Couté, Juliette Salvaing, Eric Maréchal, LIPID, Physiologie cellulaire et végétale (LPCV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Laboratoire de biogenèse membranaire (LBM), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Etude de la dynamique des protéomes (EDyP), BioSanté (UMR BioSanté), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-17-EURE-0003,CBH-EUR-GS,CBH-EUR-GS(2017), ANR-10-INBS-0008,ProFI,Infrastructure Française de Protéomique(2010), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), Salvaing, Juliette, Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID, CBH-EUR-GS - - CBH-EUR-GS2017 - ANR-17-EURE-0003 - EURE - VALID, Infrastructure Française de Protéomique - - ProFI2010 - ANR-10-INBS-0008 - INBS - VALID, and IDEX UGA - - UGA2015 - ANR-15-IDEX-0002 - IDEX - VALID
Subjects: Diatoms, Proteomics, Proteome, Nitrogen, Nitrogen starvation, Phaeodactylum, Fatty Acids, Diatom, Biochemistry, Carbon, Proteome remodelling, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Quantitative proteomics, [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Molecular Biology, [SDV.MP] Life Sciences [q-bio]/Microbiology and Parasitology, Triglycerides
Abstract: Data Paper; International audience; Diatoms are one of the largest groups in phytoplankton biodiversity. Understanding their response to nitrogen variations, present from micromolar to near-zero levels in oceans and fresh waters, is essential to comprehend their ecological success. Nitrogen starvation is used in biotechnological processes, to trigger the remodeling of carbon metabolism in the direction of fatty acids and triacylglycerol synthesis. We evaluated whole proteome changes in Phaeodactylum tricornutum after 7 days of cultivation with 5.5-mM nitrate (+N) or without any nitrogen source (-N). On a total of 3768 proteins detected in biological replicates, our analysis pointed to 384 differentially abundant proteins (DAP). Analysis of proteins of lower abundance in -N revealed an arrest of amino acid and protein syntheses, a remodeling of nitrogen metabolism, and a decrease of the proteasome abundance suggesting a decline in unselective whole-proteome decay. Analysis of proteins of higher abundance revealed the setting up of a general nitrogen scavenging system dependent on deaminases. The increase of a plastid palmitoyl-ACP desaturase appeared as a hallmark of carbon metabolism rewiring in the direction of fatty acid and triacylglycerol synthesis. This dataset is also valuable to select gene candidates for improved biotechnological properties.
Published: 2022

11. Phosphatidylinositol-4-phosphate controls autophagosome formation in Arabidopsis thaliana

Author: Rodrigo Enrique Gomez, Clément Chambaud, Josselin Lupette, Julie Castets, Stéphanie Pascal, Lysiane Brocard, Lise Noack, Yvon Jaillais, Jérôme Joubès, Amélie Bernard, Bernard, Amelie, Laboratoire de biogenèse membranaire (LBM), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Bordeaux Imaging Center (BIC), Université de Bordeaux (UB)-Institut François Magendie-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Reproduction et développement des plantes (RDP), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: Multidisciplinary, Phosphatidylinositol Phosphates, [SDV.BC.BC] Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Arabidopsis, Autophagosomes, Autophagy, General Physics and Astronomy, Autophagy-Related Proteins, General Chemistry, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, General Biochemistry, Genetics and Molecular Biology, [SDV.BV.BOT] Life Sciences [q-bio]/Vegetal Biology/Botanics
Abstract: Autophagy is an intracellular degradation mechanism critical for plant acclimation to environmental stresses. Central to autophagy is the formation of specialized vesicles, the autophagosomes, which target and deliver cargo to the lytic vacuole. How autophagosomes form in plant cells remains poorly understood. Here, we uncover the importance of the lipid phosphatidylinositol-4-phosphate in autophagy using pharmacological and genetical approaches. Combining biochemical and live-microscopy analyses, we show that PI4K activity is required for early stages of autophagosome formation. Further, our results show that the plasma membrane-localized PI4Kα1 is involved in autophagy and that a substantial portion of autophagy structures are found in proximity to the PI4P-enriched plasma membrane. Together, our study unravels critical insights into the molecular determinants of autophagy, proposing a model whereby the plasma membrane provides PI4P to support the proper assembly and expansion of the phagophore thus governing autophagosome formation in Arabidopsis.
Published: 2021

12. The Puzzling Conservation and Diversification of Lipid Droplets from Bacteria to Eukaryotes

Author: Josselin Lupette, Eric Maréchal, LIPID, Physiologie cellulaire et végétale (LPCV), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Flagship program from 1110 the CEA High Commissioner, Kloc M., ANR-10-LABX-0004,CeMEB,Labex(2010), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-0002,UGA,T-Norms(2015), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), ANR-10-LABX-0004,CeMEB,Mediterranean Center for Environment and Biodiversity(2010), and ANR-15-IDEX-0002,UGA,IDEX UGA(2015)
Subjects: 0303 health sciences, Symbiogenesis, Endosymbiosis, Chemistry, Evolution, Endoplasmic reticulum, Catabolism, Golgi apparatus, Lipid droplets, Cell biology, 03 medical and health sciences, symbols.namesake, Lipid droplet, Organelle, Architecture, symbols, Endomembrane system, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Lipid bilayer, Biogenesis, 030304 developmental biology
Abstract: Membrane compartments are amongst the most fascinating markers of cell evolution from prokaryotes to eukaryotes, some being conserved and the others having emerged via a series of primary and secondary endosymbiosis events. Membrane compartments comprise the system limiting cells (one or two membranes in bacteria, a unique plasma membrane in eukaryotes) and a variety of internal vesicular, subspherical, tubular, or reticulated organelles. In eukaryotes, the internal membranes comprise on the one hand the general endomembrane system, a dynamic network including organelles like the endoplasmic reticulum, the Golgi apparatus, the nuclear envelope, etc. and also the plasma membrane, which are linked via direct lateral connectivity (e.g. between the endoplasmic reticulum and the nuclear outer envelope membrane) or indirectly via vesicular trafficking. On the other hand, semi-autonomous organelles, i.e. mitochondria and chloroplasts, are disconnected from the endomembrane system and request vertical transmission following cell division. Membranes are organized as lipid bilayers in which proteins are embedded. The budding of some of these membranes, leading to the formation of the so-called lipid droplets (LDs) loaded with hydrophobic molecules, most notably triacylglycerol, is conserved in all clades. The evolution of eukaryotes is marked by the acquisition of mitochondria and simple plastids from Gram-positive bacteria by primary endosymbiosis events and the emergence of extremely complex plastids, collectively called secondary plastids, bounded by three to four membranes, following multiple and independent secondary endosymbiosis events. There is currently no consensus view of the evolution of LDs in the Tree of Life. Some features are conserved; others show a striking level of diversification. Here, we summarize the current knowledge on the architecture, dynamics, and multitude of functions of the lipid droplets in prokaryotes and in eukaryotes deriving from primary and secondary endosymbiosis events.
Published: 2020

13. Relationship between acyl-lipid and sterol metabolisms in diatoms

Author: Josselin Lupette, Eric Maréchal, LIPID, Physiologie cellulaire et végétale (LPCV), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ANR-10-LABX-0004,CeMEB,Mediterranean Center for Environment and Biodiversity(2010), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR–10–LABEX–04 ,GRAL,Labex, ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-02,GlycoAlps, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)
Subjects: 0301 basic medicine, Phaeodactylum, Palmitic Acid, Mevalonic Acid, Endoplasmic Reticulum, Biochemistry, Triacylglycerol, 03 medical and health sciences, chemistry.chemical_compound, Biosynthesis, Acetyl Coenzyme A, Multienzyme Complexes, Endomembrane system, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Plastids, Phaeodactylum tricornutum, Plastid, Triglycerides, Sterol, chemistry.chemical_classification, Diatoms, 030102 biochemistry & molecular biology, biology, Endosymbiosis, Chemistry, Algal Proteins, fungi, Lipid metabolism, General Medicine, Acyl-lipid, biology.organism_classification, Carbon, Sterols, 030104 developmental biology, Phytoplankton, Fatty Acids, Unsaturated, Mevalonate pathway, Polyunsaturated fatty acid
Abstract: International audience; Diatoms are a phylum of unicellular photosynthetic eukaryotes living in oceans and fresh waters, characterized by the complexity of their plastid, resulting from a secondary endosymbiosis event. In the model diatom Phaeodactylum tricornutum, fatty acids (FAs) are synthesized from acetyl-CoA in the stroma of the plastid, producing palmitic acid. FAs are elongated and desaturated to form very-long chain polyunsaturated fatty acids (VLC-PUFAs) in domains of the endomembrane system that need to be identified. Synthesis of VLC-PUFAs is coupled with their import to the core of the plastid via the so-called "omega" pathway. The biosynthesis of sterols in diatoms is likely to be localized in the endoplasmic reticulum as well as using precursors deriving from the mevalonate pathway, using acetyl-CoA as initial substrate. These metabolic modules can be characterized functionally by genetic analyzes or chemical treatments with appropriate inhibitors. Some 'metabolic modules' are characterized by a very low level of metabolic intermediates. Since some chemical treatments or genetic perturbation of lipid metabolism induce the accumulation of these intermediates, channeling processes are possibly involved, suggesting that protein-protein interactions might occur between enzymes within large size complexes or metabolons. At the junction of these modules, metabolic intermediates might therefore play dramatic roles in directing carbon fluxes from one direction to another. Here, acetyl-CoA seems determinant in the balance between TAGs and sterols. Future lines of research and potential utilization for biotechnological applications are discussed.
Published: 2020

14. Proposal of a new thraustochytrid genus Hondaea gen. nov. and comparison of its lipid dynamics with the closely related pseudo-cryptic genus Aurantiochytrium

Author: Juliette Jouhet, Fabrice Rébeillé, Mathilde Cussac, Christian Morabito, Eric Maréchal, Younès Dellero, Riccardo Aiese Cigliano, Alberto Amato, Khawla Seddiki, Walter Sanseverino, Josselin Lupette, Olivier Cagnac, Suzanne Rose, Marcel Kuntz, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Fermentalg, Sequentia Biotech SL, Trans'Alg Bpifrance project, Fermentalg-CEA partnership, ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR–10–LABEX–04 ,GRAL,Labex, Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-10-LABX-0004,CeMEB,Mediterranean Center for Environment and Biodiversity(2010), Physiologie cellulaire et végétale [2016-2019] (LPCV [2016-2019]), Fermentalg SA, UMR 1417 PCV Laboratoire de Physiologie Cellulaire Végétale. Centre de recherche Auvergne-Rhône-Alpes, Institut National de la Recherche Agronomique (INRA), Oceanomics ANR program 11-BTBR-0008, French National Research Agency ANR-10-LABEX-04 ANR-11-BTBR-0008, and PhD Flagship program of CEA high commissioner
Subjects: 0106 biological sciences, 0301 basic medicine, Canthaxanthin, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, [SDV]Life Sciences [q-bio], omega 3 fatty acid, Biology, 01 natural sciences, DNA sequencing, 03 medical and health sciences, Genus, 010608 biotechnology, Botany, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, 14. Life underwater, Mangrove, Clade, Gene, Carotenoid, ComputingMilieux_MISCELLANEOUS, Phylogeny, Sterol, chemistry.chemical_classification, Phylogenetic tree, Protist, Fatty acid, 15. Life on land, Mayotte Island, Lipids, Chemotaxonomy, Thraustochytrid, Biotechnological Potential, 030104 developmental biology, Pigment, chemistry, Omega 3, Auriantiochytrium, Sterol-thraustochytrid-triacylglycerol, Agronomy and Crop Science
Abstract: International audience; Thraustochytrids are marine protists highly ecologically relevant in mangrove environments. The family Thraustochytriaceae underwent profound taxonomical rearrangements in the last decade, with the description and emendation of several genera. Here, we identified two new thraustochytrid strains (CCAP 4062/1 and CCAP 4062/3) collected from the same mangrove environment in Mayotte Island (Indian Ocean) and representative of two sister clades in the phylogenetic Aurantiochytrium super Glade. Phylogenomic (on 2389 genes) and phylogenetic analyses on 18S rDNA sequences led us to propose the description of a new genus, Hondaea gen. nov. (CCAP 4062/3), closely related and pseudo-cryptic to Aurantiochytrium (CCAP 4062/1). Compared to Aurantiochytrium, Hondaea did not produce amoeboid cells and its zoospores were smaller. Chemotaxonomical traits, such as fatty acid, sterol, and carotenoid profiles measured along the growth curves, validated the new genus description. Genome sequencing and manual annotation of lipid metabolism genes revealed similar pathways in both strains. However, such pathways showed different dynamics during the growth phases. Aurantiochytrium accumulated carotenoids (canthaxanthin) and large amounts of triacylglycerols enriched in omega 3-docosahexaenoic acid in the stationary phase, while squalene and free cholesterol increased during the early exponential phase. In contrast, Hondaea accumulated low amounts of triacylglycerols enriched in odd and saturated fatty acids during the early exponential phase, whereas free-sterol and carotenoid contents were little affected. These results suggest that these genera evolved independently, although phylogenetically and ecologically closely related. This comparative study also showed that the biotechnological potential of thraus-tochytrids cannot be deduced solely from phylogenetic and genomic analyses.
Published: 2018

15. The architecture of lipid droplets in the diatom Phaeodactylum tricornutum

Author: Khawla Seddiki, Juliette Salvaing, Fabrice Rébeillé, Juliette Jouhet, Denis Falconet, Sabine Brugière, Yohann Couté, Eric Maréchal, Marcel Kuntz, Pierre-Henri Jouneau, Hubert Schaller, Antoine Jaussaud, Josselin Lupette, Marianne Tardif, Christian Morabito, Jean-Luc Putaux, LIPID, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la dynamique des protéomes (EDyP ), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de biologie moléculaire des plantes (IBMP), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Dynamique du protéome et biogenèse du chloroplaste (ChloroGenesis), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Flagship program from the CEA High Commissioner, French National Research Agency (ANR) ANR-11-BTBR-0008 ANR-15-IDEX-02 ANR-10-INBS-08, ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), ANR-10-INBS-0008,ProFI,Infrastructure Française de Protéomique(2010), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Etude de la dynamique des protéomes (EDyP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes (UGA), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA), Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-02,DATA@UGA,Grenoble Alpes Data Institute(2016), ANR-10-INBS-08-01/10-INBS-0008,ProFI,Infrastructure Française de Protéomique(2010), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Jouneau, Pierre-Henri, Biotech - Bioressources - Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques - - OCEANOMICS2011 - ANR-11-BTBR-0008 - BTBR - VALID, IDEX UGA - - UGA2015 - ANR-15-IDEX-0002 - IDEX - VALID, and Infrastructure Française de Protéomique - - ProFI2010 - ANR-10-INBS-0008 - INBS - VALID
Subjects: 0106 biological sciences, 0301 basic medicine, Betaine lipid, Phaeodactylum, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], 01 natural sciences, Ribosome, Triacylglycerol, [SDV.BV.BOT] Life Sciences [q-bio]/Vegetal Biology/Botanics, Histones, 03 medical and health sciences, Lipid droplet, Protein biosynthesis, ERAD pathway, Phaeodactylum tricornutum, Plastid, Secondary plastid, ComputingMilieux_MISCELLANEOUS, Diatoms, biology, Chemistry, Endoplasmic reticulum, fungi, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, biology.organism_classification, Lipid droplets, Carotenoids, 030104 developmental biology, Biochemistry, Proteome, Agronomy and Crop Science, 010606 plant biology & botany
Abstract: International audience; Diatoms are a major phylum of phytoplankton biodiversity and a resource considered for biotechnological developments, as feedstock for biofuels and applications ranging from food, human health or green chemistry. They contain a secondary plastid limited by four membranes, the outermost one being connected with the endoplasmic reticulum (ER). Upon nitrogen stress, diatoms reallocate carbon to triacylglycerol storage inside lipid droplets (LDs). The comprehensive glycerolipid and sterol composition and the architecture of diatom LDs are unknown. In Phaeodactylum tricornutum, LDs are in contact with plastid, mitochondria and uncharacterized endomembranes. We purified LDs from nitrogen-starved P. tricornutum cells to high purity level (99 mol% triacylglycerol of total glycerolipids). We used the Stramenopile Lipid Droplet Protein (StLDP) as a previously validated marker for the identity of P. tricornutum LD. Amphipathic lipids surrounding LDs consist of a betaine lipid, diacylglycerylhydroxymethyltrimethyl-beta-alanine (0.4 mol%); sulfoquinovosyldiacylglycerol (0.35 mol%); phosphatidylcholine (0.15 mol%) and one sterol, brassicasterol. By contrast with whole cell extracts, the betaine lipid from LDs only contains eicosapentaenoic acid paired with palmitoleic or palmitolenic acids. This polar lipid composition suggests a budding of LDs from the cytosolic leaflet of the plastid outermost membrane. LD pigments reveal a specific accumulation of beta-carotene. The LD proteome obtained from three independent biological replicates, based on stringent filtering of extracted data, and following subtraction of proteins downregulated by nitrogen starvation, highlights a core proteome of 86 proteins, including StLDP. LD-associated proteins suggest connections with vesicular trafficking (coatomer, clathrin), cytoskeleton, plastid and mitochondria. Unsuspected LD-associated function includes protein synthesis (ribosomes), folding (chaperones), posttranslational modifications and quality control (ubiquitination and ERAD pathway), possibly preparing translation of specific mRNAs. The detection of histone proteins, as previously demonstrated in drosophila embryo LDs, also suggests the storage of nucleosome components, preparing cell division and chromatin packaging, when cells are not stressed anymore.
Published: 2019

16. Algal remodeling in a ubiquitous planktonic photosymbiosis

Author: Josselin Lupette, Rémi Tucoulou, Pierre-Henri Jouneau, Juliette Jouhet, Johan Decelle, Sophie Marro, Yannick Schwab, Sergio Balzano, Hans H. Richnow, Giovanni Finazzi, Benoit Gallet, Giulia Veronesi, Niculina Musat, Eric Maréchal, Matthias Schmidt, Nicole L. Schieber, Clarisse Uwizeye, Hryhoriy Stryhanyuk, Light Photosynthesis & Metabolism (Photosynthesis), Physiologie cellulaire et végétale (LPCV), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry (UFZ), Institut de biologie structurale (IBS - UMR 5075 ), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Groupe modélisation et chimie théorique (MCT), Laboratoire de Chimie et Biologie des Métaux (LCBM - UMR 5249), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Royal Netherlands Institute for Sea Research (NIOZ), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), LIPID, Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de génétique et biologie moléculaire et cellulaire (IGBMC), Université Louis Pasteur - Strasbourg I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Cell Biology and Biophysics Unit, European Molecular Biology Laboratory [Grenoble] (EMBL), Helmholtz Association, The electron microscope facility is supported by the Rhoˆ ne-Alpes Region, the Fondation Recherche Medicale (FRM), the fonds FEDER, the Centre National de la Recherche Scientifique (CNRS), the CEA, the University of Grenoble Alpes (UGA), EMBL, and the GIS-Infrastrutures en Biologie Sante et Agronomie (IBISA), RGP0052 HFSP grant, CEA_DRF_impulsion (Fib-Bio) grant, ANR-10-LABX-0049,GRAL,Grenoble Alliance for Integrated Structural Cell Biology(2010), ANR-10-INBS-0002,EMBRC-France,CENTRE NATIONAL DE RESSOURCES BIOLOGIQUES MARINES(2010), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), European Project: 658442,H2020,H2020-MSCA-IF-2014,MINOTAUR(2016), European Project: EFRE, Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de biologie structurale (IBS - UMR 5075), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA), Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-10- LABX-49-01,Labex GRAL,Labex GRAL, ANR-10-INBS-02-01/10-INBS-0002,EMBRC-France,CENTRE NATIONAL DE RESSOURCES BIOLOGIQUES MARINES(2010), ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-02,DATA@UGA,Grenoble Alpes Data Institute(2016), Martin-Laffon, Jacqueline, Grenoble Alliance for Integrated Structural Cell Biology - - GRAL2010 - ANR-10-LABX-0049 - LABX - VALID, Infrastructures - CENTRE NATIONAL DE RESSOURCES BIOLOGIQUES MARINES - - EMBRC-France2010 - ANR-10-INBS-0002 - INBS - VALID, Biotech - Bioressources - Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques - - OCEANOMICS2011 - ANR-11-BTBR-0008 - BTBR - VALID, IDEX UGA - - UGA2015 - ANR-15-IDEX-0002 - IDEX - VALID, Metabolic interactions in oceanic photosymbioses - MINOTAUR - - H20202016-01-01 - 2017-12-31 - 658442 - VALID, and European Regional Development Funds - Europe fonds Saxony - EFRE - INCOMING
Subjects: 0301 basic medicine, mass spectrometry imaging, Photosynthesis, General Biochemistry, Genetics and Molecular Biology, Haptophyte, 03 medical and health sciences, 0302 clinical medicine, eukaryotes, Algae, Symbiosis, Botany, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Plastid, plastid, Cell Size, Trophic level, Phaeocystis, photosynthesis, biology, plankton, fungi, Haptophyta, food and beverages, [SDV.EE.IEO] Life Sciences [q-bio]/Ecology, environment/Symbiosis, Plankton, Metal homeostasis, biology.organism_classification, microalga, 3D electron microscopy, symbiosis, Rhizaria, 030104 developmental biology, Thylakoid, General Agricultural and Biological Sciences, single-cell imaging, Cell Division, 030217 neurology & neurosurgery, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; Photosymbiosis between single-celled hosts and microalgae is common in oceanic plankton, especially in oligotrophic surface waters. However, the functioning of this ecologically important cell-cell interaction and the subcellular mechanisms allowing the host to accommodate and benefit from its microalgae remain enigmatic. Here, using a combination of quantitative single-cell structural and chemical imaging techniques (FIB-SEM, nanoSIMS, Synchrotron X-ray fluorescence), we show that the structural organization, physiology, and trophic status of the algal symbionts (the haptophyte Phaeocystis) significantly change within their acantharian hosts compared to their free-living phase in culture. In symbiosis, algal cell division is blocked, photosynthesis is enhanced, and cell volume is increased by up to 10-fold with a higher number of plastids (from 2 to up to 30) and thylakoid membranes. The multiplication of plastids can lead to a 38-fold increase of the total plastid volume in a cell. Subcellular mapping of nutrients (nitrogen and phosphorous) and their stoichiometric ratios shows that symbiotic algae are impoverished in phosphorous and suggests a higher investment in energy-acquisition machinery rather than in growth. Nanoscale imaging also showed that the host supplies a substantial amount of trace metals (e.g., iron and cobalt), which are stored in algal vacuoles at high concentrations (up to 660 ppm). Sulfur mapping reveals a high concentration in algal vacuoles that may be a source of antioxidant molecules. Overall, this study unveils an unprecedented morphological and metabolic transformation of microalgae following their integration into a host, and it suggests that this widespread symbiosis is a farming strategy wherein the host engulfs and exploits microalgae.
Published: 2019

17. The Role of Chloroplast Membrane Lipid Metabolism in Plant Environmental Responses

Author: Christoph Benning, Ron Cook, and Josselin Lupette
Subjects: 0106 biological sciences, 0301 basic medicine, Chloroplasts, Review, Environment, Biology, oxylipin, Photosynthesis, fatty acids, 01 natural sciences, Chloroplast membrane, Membrane Lipids, 03 medical and health sciences, Jasmonate, skin and connective tissue diseases, lcsh:QH301-705.5, phospholipids, galactolipids, fungi, glycerolipids, food and beverages, Lipid metabolism, Intracellular Membranes, General Medicine, Adaptive response, Plants, Oxylipin, Lipid Metabolism, jasmonate, Cell biology, Chloroplast, 030104 developmental biology, Membrane, lcsh:Biology (General), plant stress, sense organs, 010606 plant biology & botany
Abstract: Plants are nonmotile life forms that are constantly exposed to changing environmental conditions during the course of their life cycle. Fluctuations in environmental conditions can be drastic during both day–night and seasonal cycles, as well as in the long term as the climate changes. Plants are naturally adapted to face these environmental challenges, and it has become increasingly apparent that membranes and their lipid composition are an important component of this adaptive response. Plants can remodel their membranes to change the abundance of different lipid classes, and they can release fatty acids that give rise to signaling compounds in response to environmental cues. Chloroplasts harbor the photosynthetic apparatus of plants embedded into one of the most extensive membrane systems found in nature. In part one of this review, we focus on changes in chloroplast membrane lipid class composition in response to environmental changes, and in part two, we will detail chloroplast lipid-derived signals.
Published: 2021

18. Non-Enzymatic Synthesis of Bioactive Isoprostanoids in the Diatom Phaeodactylum following Oxidative Stress

Author: Claire Vigor, Juliette Jouhet, Eric Maréchal, Joseph Vercauteren, Thierry Durand, Josselin Lupette, Guillaume Reversat, Antoine Jaussaud, Jean-Marie Galano, Camille Oger, Physiologie cellulaire et végétale (LPCV), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), CEA DRF Impulsion program, ANR-10-LABX-0004,CeMEB,Mediterranean Center for Environment and Biodiversity(2010), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-0002,UGA,IDEX UGA(2015), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ANR–10–LABEX–04 ,GRAL,Labex, ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), ANR-15-IDEX-02,GlycoAlps, and Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
Subjects: 0106 biological sciences, Physiology, Plant Science, medicine.disease_cause, Photosynthesis, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Phosphatidylcholine, Genetics, medicine, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Phaeodactylum tricornutum, Jasmonate, Hydrogen peroxide, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Reactive oxygen species, biology, biology.organism_classification, chemistry, Biochemistry, Thromboxanes, Oxidative stress, 010606 plant biology & botany
Abstract: International audience; The ecological success of diatoms requires a remarkable ability to survive many types of stress, including variations in temperature, light, salinity, and nutrient availability. On exposure to these stresses, diatoms exhibit common responses, including growth arrest, impairment of photosynthesis, production of reactive oxygen species, and accumulation of triacylglycerol (TAG). We studied the production of cyclopentane oxylipins derived from fatty acids in the diatom Phaeodactylum tricornutum in response to oxidative stress. P. tricornutum lacks the enzymatic pathway for producing cyclopentane-oxylipins, such as jasmonate, prostaglandins, or thromboxanes. In cells subjected to increasing doses of hydrogen peroxide (H2O2), we detected nonenzymatic production of isoprostanoids, including six phytoprostanes, three F2t-isoprostanes, two F3t-isoprostanes, and three F4t-neuroprostanes, by radical peroxidation of α-linolenic, arachidonic, eicosapentaenoic, and docosahexanoic acids, respectively. H2O2 also triggered photosynthesis impairment and TAG accumulation. F1t-phytoprostanes constitute the major class detected (300 pmol per 1 million cells; intracellular concentration, ∼4 µm). Only two glycerolipids, phosphatidylcholine and diacylglycerylhydroxymethyl-trimethyl-alanine, could provide all substrates for these isoprostanoids. Treatment of P. tricornutum with nine synthetic isoprostanoids produced an effect in the micromolar range, marked by the accumulation of TAG and reduced growth, without affecting photosynthesis. Therefore, the emission of H2O2 and free radicals upon exposure to stresses can lead to glycerolipid peroxidation and nonenzymatic synthesis of isoprostanoids, inhibiting growth and contributing to the induction of TAG accumulation via unknown processes. This characterization of nonenzymatic oxylipins in P. tricornutum opens a field of research on the study of processes controlled by isoprostanoid signaling in various physiological and environmental contexts in diatoms.
Published: 2018

19. Phytoplankton Glycerolipids: Challenging but Promising Prospects from Biomedicine to Green Chemistry and Biofuels

Author: Eric Maréchal, Josselin Lupette, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), La Barre Stéphane - S. Bates Stephen, Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Martin-Laffon, Jacqueline
Subjects: 0106 biological sciences, 0301 basic medicine, Green chemistry, business.industry, Chemistry, 7. Clean energy, 01 natural sciences, 03 medical and health sciences, 030104 developmental biology, Biofuel, Phytoplankton, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Biochemical engineering, business, ComputingMilieux_MISCELLANEOUS, Biomedicine, 010606 plant biology & botany
Abstract: International audience
Published: 2018

20. Ecophysiology and lipid dynamics of a eukaryotic mangrove decomposer

Author: Fabrice Rébeillé, Juliette Jouhet, Eric Maréchal, Josselin Lupette, Suzanne Rose, Alberto Amato, Christian Morabito, Younès Dellero, Coralie Metton, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Fermentalg-CEA partnership, Trans’Alg Bpifrance project, ANR-10-LABX-0004,CeMEB,Mediterranean Center for Environment and Biodiversity(2010), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR–10–LABEX–04 ,GRAL,Labex, ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
Subjects: 0301 basic medicine, Ecophysiology, Spores, Zoospore, Life cycle, Microbiology, Mangrove decomposers, Decomposer, 03 medical and health sciences, Thraustochytriaceae, Botany, Lipids metabolism, Colonization, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Ecology, Evolution, Behavior and Systematics, biology, Ecology, Protist, Aurantiochytrium limacinum, Lipid metabolism, Zoospores, biology.organism_classification, Lipid Metabolism, Lipids, Culture Media, Plant Leaves, 030104 developmental biology, Biodegradation, Environmental, Glucose, Labyrinthulomycetes, Triacylglycerols, Mangrove, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Stramenopiles
Abstract: International audience; Aurantiochytrium limacinum is an osmo-heterotrophic Stramenopile and a pioneering mangrove decomposer which is taxonomically assigned to the family of Thraustochytriaceae (class: Labyrinthulomycetes). The life cycle of A. limacinum involves different cell types including mono- and multi-nucleated cells as well as flagellated zoospores which colonize new fallen leaves. The ecological relevance of thraustochytrids is underestimated and eclipsed by their biotechnological importance, due to their ability to accumulate large amount of lipids, mainly triacylglycerols (TAGs). In this study, we aimed to understand the ecophysiological parameters that trigger zoospore production and the interplay between the life cycle of A. limacinum and its lipid metabolism. When grown in a rich medium, cells accumulated large amounts of TAGs at the end of their growth period, but no zoospores were produced. In poor media such as artificial sea water, zoospores were produced in massive quantities. In the absence of organic carbon, the zoospores remained swimming for at least 6 days, consuming their TAGs in the process. Addition of glucose rapidly triggered the maturation of the zoospores. On the basis of these data, we propose a life cycle for A. limacinum integrating the potential perturbations/changes in the environment surrounding a mangrove leaf that could lead to the production of zoospores and colonization of new areas.
Published: 2018

21. Non-Enzymatic Synthesis of Bioactive Isoprostanoids in the Diatom

Author: Josselin, Lupette, Antoine, Jaussaud, Claire, Vigor, Camille, Oger, Jean-Marie, Galano, Guillaume, Réversat, Joseph, Vercauteren, Juliette, Jouhet, Thierry, Durand, and Eric, Maréchal
Subjects: Diatoms, Oxidative Stress, Fatty Acids, Cyclopentanes, Hydrogen Peroxide, Oxylipins, Articles, Isoprostanes, Photosynthesis, Reactive Oxygen Species
Abstract: The ecological success of diatoms requires a remarkable ability to survive many types of stress, including variations in temperature, light, salinity, and nutrient availability. On exposure to these stresses, diatoms exhibit common responses, including growth arrest, impairment of photosynthesis, production of reactive oxygen species, and accumulation of triacylglycerol (TAG). We studied the production of cyclopentane oxylipins derived from fatty acids in the diatom Phaeodactylum tricornutum in response to oxidative stress. P. tricornutum lacks the enzymatic pathway for producing cyclopentane-oxylipins, such as jasmonate, prostaglandins, or thromboxanes. In cells subjected to increasing doses of hydrogen peroxide (H(2)O(2)), we detected nonenzymatic production of isoprostanoids, including six phytoprostanes, three F(2t)-isoprostanes, two F(3t)-isoprostanes, and three F(4t)-neuroprostanes, by radical peroxidation of α-linolenic, arachidonic, eicosapentaenoic, and docosahexanoic acids, respectively. H(2)O(2) also triggered photosynthesis impairment and TAG accumulation. F(1t)-phytoprostanes constitute the major class detected (300 pmol per 1 million cells; intracellular concentration, ∼4 µm). Only two glycerolipids, phosphatidylcholine and diacylglycerylhydroxymethyl-trimethyl-alanine, could provide all substrates for these isoprostanoids. Treatment of P. tricornutum with nine synthetic isoprostanoids produced an effect in the micromolar range, marked by the accumulation of TAG and reduced growth, without affecting photosynthesis. Therefore, the emission of H(2)O(2) and free radicals upon exposure to stresses can lead to glycerolipid peroxidation and nonenzymatic synthesis of isoprostanoids, inhibiting growth and contributing to the induction of TAG accumulation via unknown processes. This characterization of nonenzymatic oxylipins in P. tricornutum opens a field of research on the study of processes controlled by isoprostanoid signaling in various physiological and environmental contexts in diatoms.
Published: 2018

22. Extraction and Quantification of Lipids from Plant or Algae

Author: Valérie, Gros, Josselin, Lupette, and Juliette, Jouhet
Subjects: Chromatography, Gas, Tandem Mass Spectrometry, Plant Cells, Liquid-Liquid Extraction, Viridiplantae, Plants, Lipids, Chromatography, Liquid
Abstract: In plants and algae, the glycerolipidome changes in response to environmental modifications. For instance, in phosphate starvation, phospholipids are degraded and replaced by nonphosphorus lipids and in nitrogen starvation, storage lipids accumulate. In addition to the well-known applications of oil crops for food, algae lipids are becoming a model for potential applications in health, biofuel, and green chemistry and are used as a platform for genetic engineering. It is therefore important to measure accurately and quickly the glycerolipid content in plants and algae. Here we describe the methods to extract the lipid, quantify the fatty acid amount of the lipid extract and to quantify the different lipid classes that are present in these samples.
Published: 2018

23. Extraction and Quantification of Lipids from Plant or Algae

Author: Juliette Jouhet, Valérie Gros, Josselin Lupette, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Marechal Eric, and Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
Subjects: 0106 biological sciences, 0301 basic medicine, Extraction, 7. Clean energy, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Algae, Quantification, Fatty acid methyl ester, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Food science, chemistry.chemical_classification, Gas chromatography, biology, Mass spectrometry, Chemistry, Extraction (chemistry), Fatty acid, food and beverages, Lipid, Phosphate, biology.organism_classification, 030104 developmental biology, 13. Climate action, Biofuel, lipids (amino acids, peptides, and proteins), HPLC, 010606 plant biology & botany
Abstract: International audience; In plants and algae, the glycerolipidome changes in response to environmental modifications. For instance, in phosphate starvation, phospholipids are degraded and replaced by nonphosphorus lipids and in nitrogen starvation, storage lipids accumulate. In addition to the well-known applications of oil crops for food, algae lipids are becoming a model for potential applications in health, biofuel, and green chemistry and are used as a platform for genetic engineering. It is therefore important to measure accurately and quickly the glycerolipid content in plants and algae. Here we describe the methods to extract the lipid, quantify the fatty acid amount of the lipid extract and to quantify the different lipid classes that are present in these samples.
Published: 2018

24. Screening for Biologically Annotated Drugs That Trigger Triacylglycerol Accumulation in the Diatom Phaeodactylum

Author: Khawla Seddiki, Eric Maréchal, Fabrice Rébeillé, Valérie Gros, Josselin Lupette, Melissa Conte, Caroline Barette, Coline Meï, Juliette Jouhet, Lina Juana Dolch, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Groupe Plateforme et Moyens Scientifiques et techniques communs / Centre de Criblage pour Molécules Bio-Actives (GPMS / CMBA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Genetics and Chemogenomics (GenChem), Laboratoire de Biologie à Grande Échelle (BGE - UMR S1038), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Agence Nationale de la Recherche (DiaDomOil), Commissariat a l'Energie Atomique, Agence Nationale de la Recherche Programme Investissement d'Avenir (Oceanomics), and Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
Subjects: 0301 basic medicine, Active molecule screening, Physiology, Estrone, Membrane lipids, Phenotypic screening, Drug Evaluation, Preclinical, Plant Science, Ethinyl Estradiol, Phaeodactylum tricornutum, 03 medical and health sciences, chemistry.chemical_compound, Biosynthesis, Biofuel, Genetics, Microalgae, Ethylnylestradiol, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Lipids production, Triglycerides, chemistry.chemical_classification, Diatoms, Biological Products, Triacylglycerol accumulation, biology, Dose-Response Relationship, Drug, Catabolism, Fatty acid, Cytochrome P450, Glycerolipids, Diatom, Articles, Feedstock, biology.organism_classification, Estrogen, Sterol metabolism, 3. Good health, 030104 developmental biology, chemistry, Biochemistry, Gene Expression Regulation, Metabolic pathway, biology.protein, [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition, Polyunsaturated fatty acid
Abstract: International audience; Microalgae are a promising feedstock for the production of triacylglycerol (TAG) for a variety of potential applications, ranging from food and human health to biofuels and green chemistry. However, obtaining high TAG yields is challenging. A phenotypic assay for the accumulation of oil droplets was developed to screen a library of 1,200 drugs, annotated with pharmacology information, to select compounds that trigger TAG accumulation in the diatom Phaeodactylum tricornutum Using this screen, we identified 34 molecules acting in a dose-dependent manner. Previously characterized targets of these compounds include cell division and cell signaling effectors, membrane receptors and transporters, and sterol metabolism. Among the five compounds possibly acting on sterol metabolism, we focused our study on ethynylestradiol, a synthetic form of estrogen that is used in contraceptive pills and known for its ecological impact as an endocrine disruptor. Ethynylestradiol impaired the production of very-long-chain polyunsaturated fatty acids, destabilized the galactolipid versus phospholipid balance, and triggered the recycling of fatty acids from membrane lipids to TAG. The P. tricornutum transcriptomic response to treatment with ethynylestradiol was consistent with the reallocation of carbon from sterols to acetyl-coenzyme A and TAG. The mode of action and catabolism of ethynylestradiol are unknown but might involve several up-regulated cytochrome P450 proteins. A fatty acid elongase, Δ6-ELO-B1, might be involved in the impairment of very-long-chain polyunsaturated fatty acids and fatty acid turnover. This phenotypic screen opens new perspectives for the exploration of novel bioactive molecules, potential target genes, and pathways controlling TAG biosynthesis. It also unraveled the sensitivity of diatoms to endocrine disruptors, highlighting an impact of anthropogenic pollution on phytoplankton.
Published: 2018

25. Nitric Oxide Mediates Nitrite-Sensing and Acclimation and Triggers a Remodeling of Lipids

Author: Fabrice Rébeillé, Mariette Bedhomme, Leonardo Magneschi, Laurent Fourage, Juliette Jouhet, Michael Reith, Séverine Collin, Eric Maréchal, Lina-Juana Dolch, Frédéric Laeuffer, Christelle Richard, Josselin Lupette, Guillaume Tourcier, Melissa Conte, Patrick J. McGinn, Khawla Seddiki, Robert S. Richards, Erwan Corre, Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Total Refining Chemicals, UMR 1417 PCV Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique (CNRS), Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Aquatic and Crop Resource Development, National Research Council of Canada (NRC), National Research Council of Canada’s Algal Carbon Conversion Program, ANR-12-BIME-0005,DiaDomOil,Domestication des diatomées pour la production de biocarburants(2012), ANR-11-BTBR-0008/11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), ANR-11-BTBR-0008,OCEANOMICS,Biotechnologies et bioressources pour la valorisation des écosystèmes marins planctoniques(2011), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Fédération de recherche de Roscoff (FR2424), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 0301 basic medicine, Transcription, Genetic, Physiology, Phaeodactylum, Acclimatization, Plant Science, Aquatic ecosystem, MGDG, chemistry.chemical_compound, NOA, Gene Expression Regulation, Plant, Climate change, Phosphoenolpyruvate dehydrogenase, Plastids, Nitrite, Cell Death, Galactosyltransferases, Pollution, Adaptation, Physiological, Biochemistry, Caspases, Metabolic pathway, Ferredoxins, triacylglycerol, Phosphoenolpyruvate carboxykinase, Intracellular, Nitrite Reductases, Monogalactosyldiacylglycerol, Biology, S-Nitroso-N-Acetylpenicillamine, Nitrate reductase, Arginine, Nitric Oxide, Nitric oxide, 03 medical and health sciences, Biosynthesis, Genetics, nitrogen cycle, Signaling and Response, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Nitrogen metabolism, Nitrites, Triglycerides, Diatoms, Aldehydes, Phytoplancton, Galactolipids, Gene Expression Profiling, fungi, Diatom, Nitrite reductase, Lipid Metabolism, Triacylglycerol biosynthesis, 030104 developmental biology, chemistry, 13. Climate action, Gene expression, S-Nitroso-N-acetylpenicillamine
Abstract: International audience; Nitric oxide (NO) is an intermediate of the nitrogen cycle, an industrial pollutant, and a marker of climate change. NO also acts as a gaseous transmitter in a variety of biological processes. The impact of environmental NO needs to be addressed. In diatoms, a dominant phylum in phytoplankton, NO was reported to mediate programmed cell death in response to diatom-derived polyunsaturated aldehydes. Here, using the Phaeodactylum Pt1 strain, 2E,4E-decadienal supplied in the micromolar concentration range led to a nonspecific cell toxicity. We reexamined NO biosynthesis and response in Phaeodactylum NO inhibits cell growth and triggers triacylglycerol (TAG) accumulation. Feeding experiments indicate that NO is not produced from Arg but via conversion of nitrite by the nitrate reductase. Genome-wide transcriptional analysis shows that NO up-regulates the expression of the plastid nitrite reductase and genes involved in the subsequent incorporation of ammonium into amino acids, via both Gln synthesis and Orn-urea pathway. The phosphoenolpyruvate dehydrogenase complex is also up-regulated, leading to the production of acetyl-CoA, which can feed TAG accumulation upon exposure to NO. Transcriptional reprogramming leading to higher TAG content is balanced with a decrease of monogalactosyldiacylglycerol (MGDG) in the plastid via posttranslational inhibition of MGDG synthase enzymatic activity by NO. Intracellular and transient NO emission acts therefore at the basis of a nitrite-sensing and acclimating system, whereas a long exposure to NO can additionally induce a redirection of carbon to neutral lipids and a stress response.
Published: 2017

26. Marinobacter Dominates the Bacterial Community of the Ostreococcus tauri Phycosphere in Culture

Author: Marc Krasovec, Sophie Sanchez-Ferandin, Raphaël Lami, Gwenael Piganeau, Hervé Moreau, Nigel Grimsley, Josselin Lupette, Biologie intégrative des organismes marins (BIOM), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Physiologie cellulaire et végétale (LPCV), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-PIERRE FABRE-EDF (EDF)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Universites, SATS-SU [ANR-11-IDEX-0004-02], PHYTNESS project [ANR-I3-JSV6-0005], Michael Thomas-Poulsen, Tony Gutierrez, Garret Suen, Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Sanchez-Ferandin, Sophie
Subjects: 0301 basic medicine, Microbiology (medical), 030106 microbiology, lcsh:QR1-502, Chlorophyta, Microbiology, lcsh:Microbiology, Ostreococcus tauri, Ostreococcus, 03 medical and health sciences, Algae, Phytoplankton, Botany, Marinobacter sp, 14. Life underwater, Marinobacter algicola, bacteria, Original Research, picoalgae, interactions, phytoplankton, biology, fungi, Marinobacter, biology.organism_classification, 030104 developmental biology, Diatom, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology
Abstract: International audience; Microalgal–bacterial interactions are commonly found in marine environments and are well known in diatom cultures maintained in laboratory. These interactions also exert strong effects on bacterial and algal diversity in the oceans. Small green eukaryote algae of the class Mamiellophyceae (Chlorophyta) are ubiquitous and some species, such as Ostreococcus spp., are particularly important in Mediterranean coastal lagoons, and are observed as dominant species during phytoplankton blooms in open sea. Despite this, little is known about the diversity of bacteria that might facilitate or hinder O. tauri growth. We show, using rDNA 16S sequences, that the bacterial community found in O. tauri RCC4221 laboratory cultures is dominated by γ-proteobacteria from the Marinobacter genus, regardless of the growth phase of O. tauri RCC4221, the photoperiod used, or the nutrient conditions (limited in nitrogen or phosphorous) tested. Several strains of Marinobacter algicola were detected, all closely related to strains found in association with taxonomically distinct organisms, particularly with dinoflagellates and coccolithophorids. These sequences were more distantly related to M. adhaerens, M. aquaeoli and bacteria usually associated to euglenoids. This is the first time, to our knowledge, that distinct Marinobacter strains have been found to be associated with a green alga in culture.
Published: 2016

27. Phosphatidylinositol-4-phosphate joins the dance of plant autophagosome formation

Author: Rodrigo Enrique Gomez, Julie Castets, Josselin Lupette, Clément Chambaud, Jérôme Joubès, and Amélie Bernard
Subjects: Cell Biology, Molecular Biology
Abstract: In plants, macroautophagy/autophagy is a key mechanism that contributes to their ability to cope with a wide range of environmental constraints such as drought, nutrient starvation or pathogen resistance. Nevertheless, the molecular mechanisms of plant autophagy, and notably that of autophagosome formation, remain poorly understood. As the starting point of our recent paper, we considered the potential functional contribution of lipids in the numerous membrane-remodeling steps involved in this process. By combining biochemistry, genetics, cell biology and high-resolution 3D imaging, we unraveled the function of the lipid phosphatidylinositol-4-phosphate (PtdIns4P) in autophagy in
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27 results on '"Josselin Lupette"'

1. Phosphatidylinositol-4-phosphate controls autophagosome formation in Arabidopsis thaliana

2. Stepwise Biogenesis of Subpopulations of Lipid Droplets in Nitrogen Starved Phaeodactylum tricornutum Cells

3. Features of the Opportunistic Behaviour of the Marine Bacterium Marinobacter algicola in the Microalga Ostreococcus tauri Phycosphere

4. How Lipids Contribute to Autophagosome Biogenesis, a Critical Process in Plant Responses to Stresses

5. The Role of Chloroplast Membrane Lipid Metabolism in Plant Environmental Responses

6. Correction: LC-MS/MS versus TLC plus GC methods: Consistency of glycerolipid and fatty acid profiles in microalgae and higher plant cells and effect of a nitrogen starvation.

7. LC-MS/MS versus TLC plus GC methods: Consistency of glycerolipid and fatty acid profiles in microalgae and higher plant cells and effect of a nitrogen starvation.

8. Marinobacter dominates the bacterial community of the Ostreococcus tauri phycosphere in culture

9. Human health benefits of very-long-chain polyunsaturated fatty acids from microalgae

10. Quantitative proteomic analyses reveal the impact of nitrogen starvation on the proteome of the model diatom Phaeodactylum tricornutum

11. Phosphatidylinositol-4-phosphate controls autophagosome formation in Arabidopsis thaliana

12. The Puzzling Conservation and Diversification of Lipid Droplets from Bacteria to Eukaryotes

13. Relationship between acyl-lipid and sterol metabolisms in diatoms

14. Proposal of a new thraustochytrid genus Hondaea gen. nov. and comparison of its lipid dynamics with the closely related pseudo-cryptic genus Aurantiochytrium

15. The architecture of lipid droplets in the diatom Phaeodactylum tricornutum

16. Algal remodeling in a ubiquitous planktonic photosymbiosis

17. The Role of Chloroplast Membrane Lipid Metabolism in Plant Environmental Responses

18. Non-Enzymatic Synthesis of Bioactive Isoprostanoids in the Diatom Phaeodactylum following Oxidative Stress

19. Phytoplankton Glycerolipids: Challenging but Promising Prospects from Biomedicine to Green Chemistry and Biofuels

20. Ecophysiology and lipid dynamics of a eukaryotic mangrove decomposer

21. Non-Enzymatic Synthesis of Bioactive Isoprostanoids in the Diatom

22. Extraction and Quantification of Lipids from Plant or Algae

23. Extraction and Quantification of Lipids from Plant or Algae

24. Screening for Biologically Annotated Drugs That Trigger Triacylglycerol Accumulation in the Diatom Phaeodactylum

25. Nitric Oxide Mediates Nitrite-Sensing and Acclimation and Triggers a Remodeling of Lipids

26. Marinobacter Dominates the Bacterial Community of the Ostreococcus tauri Phycosphere in Culture

27. Phosphatidylinositol-4-phosphate joins the dance of plant autophagosome formation

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27 results on '"Josselin Lupette"'

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