References of "Cardol, Pierre"
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See detailCharacterization of fermentation pathways and their interaction with photosynthesis in different microalgae
Gain, Gwenaëlle ULiege; Berne, Nicolas; Remacle, Claire ULiege et al

Poster (2019, February 07)

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See detailMaximal cyclic electron flow rate is independent of PGRL1 in Chlamydomonas.
Nawrocki, W. J.; Bailleul, B.; Cardol, Pierre ULiege et al

in Biochimica et biophysica acta. Bioenergetics (2019), 1860(5), 425-432

Cyclic electron flow (CEF) is defined as a return of the reductants from the acceptor side of Photosystem I (PSI) to the pool of its donors via the cytochrome b6f. It is described to be complementary to ... [more ▼]

Cyclic electron flow (CEF) is defined as a return of the reductants from the acceptor side of Photosystem I (PSI) to the pool of its donors via the cytochrome b6f. It is described to be complementary to the linear electron flow and essential for photosynthesis. However, despite many efforts aimed to characterize CEF, its pathway and its regulation modes remain equivocal, and its physiological significance is still not clear. Here we use novel spectroscopic to measure the rate of CEF at the onset of light in the green alga Chlamydomonas reinhardtii. The initial redox state of the photosynthetic chain or the oxygen concentration do not modify the initial maximal rate of CEF (60 electrons per second per PSI) but rather strongly influence its duration. Neither the maximal rate nor the duration of CEF are different in the pgrl1 mutant compared to the wild type, disqualifying PGRL1 as the ferredoxin-plastoquinone oxidoreductase involved in the CEF mechanism. [less ▲]

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See detailThe mechanism of cyclic electron flow.
Nawrocki, W. J.; Bailleul, B.; Picot, D. et al

in Biochimica et biophysica acta. Bioenergetics (2019), 1860(5), 433-438

Apart from the canonical light-driven linear electron flow (LEF) from water to CO2, numerous regulatory and alternative electron transfer pathways exist in chloroplasts. One of them is the cyclic electron ... [more ▼]

Apart from the canonical light-driven linear electron flow (LEF) from water to CO2, numerous regulatory and alternative electron transfer pathways exist in chloroplasts. One of them is the cyclic electron flow around Photosystem I (CEF), contributing to photoprotection of both Photosystem I and II (PSI, PSII) and supplying extra ATP to fix atmospheric carbon. Nonetheless, CEF remains an enigma in the field of functional photosynthesis as we lack understanding of its pathway. Here, we address the discrepancies between functional and genetic/biochemical data in the literature and formulate novel hypotheses about the pathway and regulation of CEF based on recent structural and kinetic information. [less ▲]

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See detailImpact of heat stress on the photosynthetic electron transport in golden jellyfish Mastigias papua
Vega de Luna, Felix ULiege; Dang, Kieu Van; Roberty, Stéphane ULiege et al

Poster (2018, June 26)

Phenomena as the strong El Niño Southern-Oscillation (ENSO) in 1997/1998, can lead to fast changes in sea water temperature. Some species, like the golden jellyfish Mastigias papua (Scyphozoa ... [more ▼]

Phenomena as the strong El Niño Southern-Oscillation (ENSO) in 1997/1998, can lead to fast changes in sea water temperature. Some species, like the golden jellyfish Mastigias papua (Scyphozoa, Rhizostomeae), are sensible to changes in the environment, and are being used as sensors to chemical pollution and global temperature changes due to their ecological responses to disturbances. The aim of this study was to compare the photosynthetic electron flow and its alternative electron flows upon heat stress in oceanic and lake golden jellyfishes. [less ▲]

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See detailOxidative phosphorylation supercomplexes and respirasome reconstitution of the colorless alga Polytomella sp
Miranda Astudillo, Héctor Vicente ULiege; Colina-Tenorio, Lilia; Jiménez-Suárez, Alejandra et al

in Biochimica et Biophysica Acta. Bioenergetics (2018), 1859

The proposal that the respiratory complexes can associate with each other in larger structures named super- complexes (SC) is generally accepted. In the last decades most of the data about this ... [more ▼]

The proposal that the respiratory complexes can associate with each other in larger structures named super- complexes (SC) is generally accepted. In the last decades most of the data about this association came from studies in yeasts, mammals and plants, and information is scarce in other lineages. Here we studied the su- pramolecular association of the F1FO-ATP synthase (complex V) and the respiratory complexes I, III and IV of the colorless alga Polytomella sp. with an approach that involves solubilization using mild detergents, n-dodecyl-β-D- maltoside (DDM) or digitonin, followed by separation of native protein complexes by electrophoresis (BN- PAGE), after which we identified oligomeric forms of complex V (mainly V2 and V4) and different respiratory supercomplexes (I/IV6, I/III4, I/IV). In addition, purification/reconstitution of the supercomplexes by anion exchange chromatography was also performed. The data show that these complexes have the ability to strongly associate with each other and form DDM-stable macromolecular structures. The stable V4 ATPase oligomer was observed by electron-microscopy and the association of the respiratory complexes in the so-called “respirasome” was able to perform in-vitro oxygen consumption. [less ▲]

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See detailHost-pathogen biotic interactions shaped vitamin K metabolism in Archaeplastida
Cenci, U.; Qiu, H.; Pillonel, T. et al

in Scientific Reports (2018), 8(1),

Menaquinone (vitamin K2) shuttles electrons between membrane-bound respiratory complexes under microaerophilic conditions. In photosynthetic eukaryotes and cyanobacteria, phylloquinone (vitamin K1 ... [more ▼]

Menaquinone (vitamin K2) shuttles electrons between membrane-bound respiratory complexes under microaerophilic conditions. In photosynthetic eukaryotes and cyanobacteria, phylloquinone (vitamin K1) participates in photosystem I function. Here we elucidate the evolutionary history of vitamin K metabolism in algae and plants. We show that Chlamydiales intracellular pathogens made major genetic contributions to the synthesis of the naphthoyl ring core and the isoprenoid side-chain of these quinones. Production of the core in extremophilic red algae is under control of a menaquinone (Men) gene cluster consisting of 7 genes that putatively originated via lateral gene transfer (LGT) from a chlamydial donor to the plastid genome. In other green and red algae, functionally related nuclear genes also originated via LGT from a non-cyanobacterial, albeit unidentified source. In addition, we show that 3–4 of the 9 required steps for synthesis of the isoprenoid side chains are under control of genes of chlamydial origin. These results are discussed in the light of the hypoxic response experienced by the cyanobacterial endosymbiont when it gained access to the eukaryotic cytosol. © 2018, The Author(s). [less ▲]

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See detailThe atypical subunit composition of respiratory complexes I and IV is associated with original extra structural domains in Euglena gracilis.
Miranda-Astudillo, H. V.; Yadav, K. N. S.; Colina-Tenorio, L. et al

in Scientific Reports (2018), 8(1), 9698

In mitochondrial oxidative phosphorylation, electron transfer from NADH or succinate to oxygen by a series of large protein complexes in the inner mitochondrial membrane (complexes I-IV) is coupled to the ... [more ▼]

In mitochondrial oxidative phosphorylation, electron transfer from NADH or succinate to oxygen by a series of large protein complexes in the inner mitochondrial membrane (complexes I-IV) is coupled to the generation of an electrochemical proton gradient, the energy of which is utilized by complex V to generate ATP. In Euglena gracilis, a non-parasitic secondary green alga related to trypanosomes, these respiratory complexes totalize more than 40 Euglenozoa-specific subunits along with about 50 classical subunits described in other eukaryotes. In the present study the Euglena proton-pumping complexes I, III, and IV were purified from isolated mitochondria by a two-steps liquid chromatography approach. Their atypical subunit composition was further resolved and confirmed using a three-steps PAGE analysis coupled to mass spectrometry identification of peptides. The purified complexes were also observed by electron microscopy followed by single-particle analysis. Even if the overall structures of the three oxidases are similar to the structure of canonical enzymes (e.g. from mammals), additional atypical domains were observed in complexes I and IV: an extra domain located at the tip of the peripheral arm of complex I and a "helmet-like" domain on the top of the cytochrome c binding region in complex IV. [less ▲]

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See detailThe peculiar NPQ regulation in the stramenopile Phaeomonas sp. challenges the xanthophyll cycle dogma
Berne, Nicolas ULiege; Fabryova, T.; Istaz, B. et al

in Biochimica et Biophysica Acta. Bioenergetics (2018), 1859(7), 491-500

In changing light conditions, photosynthetic organisms develop different strategies to maintain a fine balance between light harvesting, photochemistry, and photoprotection. One of the most widespread ... [more ▼]

In changing light conditions, photosynthetic organisms develop different strategies to maintain a fine balance between light harvesting, photochemistry, and photoprotection. One of the most widespread photoprotective mechanisms consists in the dissipation of excess light energy in the form of heat in the photosystem II antenna, which participates to the Non Photochemical Quenching (NPQ) of chlorophyll fluorescence. It is tightly related to the reversible epoxidation of xanthophyll pigments, catalyzed by the two enzymes, the violaxanthin deepoxidase and the zeaxanthin epoxidase. In Phaeomonas sp. (Pinguiophyte, Stramenopiles), we show that the regulation of the heat dissipation process is different from that of the green lineage: the NPQ is strictly proportional to the amount of the xanthophyll pigment zeaxanthin and the xanthophyll cycle enzymes are differently regulated. The violaxanthin deepoxidase is already active in the dark, because of a low luminal pH, and the zeaxanthin epoxidase shows a maximal activity under moderate light conditions, being almost inactive in the dark and under high light. This light-dependency mirrors the one of NPQ: Phaeomonas sp. displays a large NPQ in the dark as well as under high light, which recovers under moderate light. Our results pinpoint zeaxanthin epoxidase activity as the prime regulator of NPQ in Phaeomonas sp. and therefore challenge the deepoxidase-regulated xanthophyll cycle dogma. © 2018 Elsevier B.V. [less ▲]

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See detailDispositif pour la production d'hydrogène gazeux
Lorge, Philippe ULiege; Remacle, Claire ULiege; Gerin, Stéphanie ULiege et al

Patent (2017)

Dispositif de dissociation d’une phase aqueuse pour produire de l’hydrogène gazeux, ledit dispositif comprenant : - une première zone comprenant ladite phase aqueuse, - un moyen de capture d’électrons ... [more ▼]

Dispositif de dissociation d’une phase aqueuse pour produire de l’hydrogène gazeux, ledit dispositif comprenant : - une première zone comprenant ladite phase aqueuse, - un moyen de capture d’électrons, - un moyen de capture de protons, et - une source énergétique, ledit dispositif comprenant une deuxième zone non aqueuse et étant conçu pour réaliser ladite réaction de réduction au niveau de ladite deuxième zone non aqueuse. [less ▲]

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See detailDISPOSITIF PHOTO-CATALYTIQUE POUR LA PRODUCTION D'HYDROGENE GAZEUX
Lorge, Philippe ULiege; Remacle, Claire ULiege; Gerin, Stéphanie ULiege et al

Patent (2017)

Dispositif photo-catalytique de dissociation d’une phase aqueuse pour produire de l’hydrogène gazeux, ledit dispositif étant agencé de sorte que qu’au moins un système photo-catalytique en contact avec ... [more ▼]

Dispositif photo-catalytique de dissociation d’une phase aqueuse pour produire de l’hydrogène gazeux, ledit dispositif étant agencé de sorte que qu’au moins un système photo-catalytique en contact avec ladite phase aqueuse puisse être irradié par une source lumineuse pour produire, via une réaction d’oxydation de ladite phase aqueuse, de l’oxygène gazeux, des électrons et des protons, ledit dispositif comprenant : - un première zone comprenant ladite phase aqueuse, et - un moyen de capture desdits protons agencé pour réaliser une réaction de réduction desdits protons par lesdits électrons afin de produire de l’hydrogène gazeux, ledit dispositif comprenant une deuxième zone non aqueuse et étant conçu pour réaliser ladite réaction de réduction au niveau de ladite deuxième zone non aqueuse. [less ▲]

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See detailIn vivo chlorophyll fluorescence screening allows the isolation of a Chlamydomonas mutant defective for NDUFAF3, an assembly factor involved in mitochondrial complex I assembly
Massoz, Simon; Hanikenne, Marc ULiege; Bailleul, Benjamin et al

in Plant Journal (2017), 92(4), 584-595

The qualitative screening method to select complex I mutants in the microalga Chlamydomonas, based on reduced growth under heterotrophic condition, is not suited for high throughput screening. In order to ... [more ▼]

The qualitative screening method to select complex I mutants in the microalga Chlamydomonas, based on reduced growth under heterotrophic condition, is not suited for high throughput screening. In order to develop a fast screening method based on measurements of chlorophyll fluorescence, we first demonstrated that complex I mutants displayed decreased photosystem II efficiency in the genetic background of a photosynthetic mutation leading to reduced formation of the electrochemical proton gradient in the chloroplast (pgrl1 mutation). In contrast, single mutants (complex I and pgrl1 mutants) could not be distinguished from wild type by their photosystem II efficiency in the tested conditions. We next performed an insertional mutagenesis on the pgrl1 mutant. Out of ~3000 hygromycin-resistant insertional transformants, 46 had decreased photosystem II efficiency and three were complex I mutants. One of the mutants was tagged and whole genome sequencing identified the resistance cassette in NDUFAF3, a homolog of the human NDUFAF3 gene, encoding for an assembly factor involved in complex I assembly. Complemented strains showed restored complex I activity and assembly. Overall, we described here a screening method which is fast and particularly suited for identification of Chlamydomonas complex I mutants. [less ▲]

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