References of "Cardol, Pierre"
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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 (The) (2017), 17(8), 2045-2054

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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See detailPhotosynthetic electrons transfer in Thalassiosira pseudonana in anoxic condition
Berne, Nicolas ULiege; Cardol, Pierre ULiege

Poster (2017, July)

Photosynthetic activity of Thalassiosira pseudonana in anoxic condition Berne Nicolas, Pierre Cardol. Diatoms are responsible for a large part of oceanic primary production. This ecological success ... [more ▼]

Photosynthetic activity of Thalassiosira pseudonana in anoxic condition Berne Nicolas, Pierre Cardol. Diatoms are responsible for a large part of oceanic primary production. This ecological success suggests that they have developed a range of strategies to cope with various biotic and abiotic stress factors. In this respect, several diatoms can experience more or less prolonged periods in hypoxia or anoxia. In similar environmental conditions, several green algae express hydrogenase that is connected to photosynthesis and is able to oxidize reduced ferredoxin. Together with photosynthetic cyclic electron flow around PS1 (CEF), this hydrogenase allows the Calvin-Benson Cycle (CBB) reactivation by increasing the ATP/NADPH ratio (Godaux et al, 2015) In this work, we show that in the centric diatom Thalassiosira pseudonana the availability of photosynthetic electron acceptors decreases during the two first hours of dark anoxic acclimation and reaches a steady state (up to 48h). The existence of some metabolic pathways that oxidized photosynthetic cofactors in anoxia is discussed in the light of the recent report on the putative presence of several fermentative pathways in T. pseudonana (Atteia et al, 2013). We also show that photosynthetic reactivation after prolonged periods of dark anoxic acclimation relies on high and transient CEF. This last result contrasts with the absence of high CEF in oxic condition in diatoms (Bailleul et al, 2015). Altogether our results point to peculiar regulatory mechanisms (CEF and fermentation) that might contribute to sustain photosynthetic capacity in diatoms in hypoxic / anoxic environments. Godaux D. et al, 2015. Plant Physiol 168: 648–58 Bailleul B, et al, 2015. Nature 524: 366–369 Atteia A, et al, 2013. Biochim Biophys Acta - Bioenerg 1827: 210–223 [less ▲]

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See detailPhotosynthetic activity of Thalassiosira pseudonana in anoxic condition
Berne, Nicolas ULiege; Cardol, Pierre ULiege

Poster (2017, July)

Photosynthetic activity of Thalassiosira pseudonana in anoxic condition Berne Nicolas, Pierre Cardol. Diatoms are responsible for a large part of oceanic primary production. This ecological success ... [more ▼]

Photosynthetic activity of Thalassiosira pseudonana in anoxic condition Berne Nicolas, Pierre Cardol. Diatoms are responsible for a large part of oceanic primary production. This ecological success suggests that they have developed a range of strategies to cope with various biotic and abiotic stress factors. In this respect, several diatoms can experience more or less prolonged periods in hypoxia or anoxia. In similar environmental conditions, several green algae express hydrogenase that is connected to photosynthesis and is able to oxidize reduced ferredoxin. Together with photosynthetic cyclic electron flow around PS1 (CEF), this hydrogenase allows the Calvin-Benson Cycle (CBB) reactivation by increasing the ATP/NADPH ratio (Godaux et al, 2015) In this work, we show that in the centric diatom Thalassiosira pseudonana the availability of photosynthetic electron acceptors decreases during the two first hours of dark anoxic acclimation and reaches a steady state (up to 48h). The existence of some metabolic pathways that oxidized photosynthetic cofactors in anoxia is discussed in the light of the recent report on the putative presence of several fermentative pathways in T. pseudonana (Atteia et al, 2013). We also show that photosynthetic reactivation after prolonged periods of dark anoxic acclimation relies on high and transient CEF. This last result contrasts with the absence of high CEF in oxic condition in diatoms (Bailleul et al, 2015). Altogether our results point to peculiar regulatory mechanisms (CEF and fermentation) that might contribute to sustain photosynthetic capacity in diatoms in hypoxic / anoxic environments. Godaux D. et al, 2015. Plant Physiol 168: 648–58 Bailleul B, et al, 2015. Nature 524: 366–369 Atteia A, et al, 2013. Biochim Biophys Acta - Bioenerg 1827: 210–223 [less ▲]

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See detailBioenergetics in microlagae. Electron transfer chains : structure, function & evolution.
Cardol, Pierre ULiege

Scientific conference (2017, March 14)

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See detailAtypical composition and structure of the mitochondrial dimeric ATP synthase from Euglena gracilis
Yadav, K.N. Sathish; Miranda Astudillo, Héctor Vicente ULiege; Colina-Tenorio, Lili et al

in Biochimica et Biophysica Acta-Bioenergetics (2017), 1858(4), 267-275

Mitochondrial respiratory-chain complexes from Euglenozoa comprise classical subunits described in other eukaryotes (i.e. mammals and fungi) and subunits that are restricted to Euglenozoa (e.g. Euglena ... [more ▼]

Mitochondrial respiratory-chain complexes from Euglenozoa comprise classical subunits described in other eukaryotes (i.e. mammals and fungi) and subunits that are restricted to Euglenozoa (e.g. Euglena gracilis and Trypanosoma brucei). Here we studied the mitochondrial F1FO-ATP synthase (or Complex V) from the photosynthetic eukaryote E. gracilis in detail. The enzyme was purified by a two-step chromatographic procedure and its subunit composition was resolved by a three-dimensional gel electrophoresis (BN/SDS/SDS). Twenty-two different subunits were identified by mass-spectrometry analyses among which the canonical alpha, beta, gamma, delta, epsilon and OSCP subunits, and at least seven subunits previously found in Trypanosoma. The ADP/ATP carrier was also associated to the ATP synthase into a dimeric ATP synthasome. Single-particle analysis by transmission electron microscopy of the dimeric ATP synthase indicated that the structures of both the catalytic and central rotor parts are conserved while other structural features are original. These new features include a large membrane-spanning region joining the monomers, an external peripheral stalk and a structure that goes through the membrane and reaches the inter membrane space below the c-ring, the latter having not been reported for any mitochondrial F-ATPase. [less ▲]

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See detailNear-neighbor interactions of the membrane-embedded subunits of the mitochondrial ATP synthase of a chlorophycean alga
Sánchez-Vásquez, Lorenzo; Vázquez-Acevedo, M; de la Mora, J et al

in Biochimica et Biophysica Acta-Bioenergetics (2017), 1858(7), 497-509

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See detailAnalysisi of Euglena gracilis proteome under mixotrophic conditions
Córdoba Jacoste, Francisco Javier ULiege; Perez, Emilie; Baurain, Denis ULiege et al

Conference (2017)

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See detailAnalysis of Euglena gracilis proteome under mixotrophic conditions
Córdoba Jacoste, Francisco Javier ULiege; Perez, Emilie; Baurain, Denis ULiege et al

Scientific conference (2017)

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See detailFrom light capture to metabolic needs, oxygenic photosynthesis is an ever-expanding field of study in plants, algae and cyanobacteria.
Cardol, Pierre ULiege; Krieger-Liskay, A.

in Physiologia Plantarum (2017), 61(1), 2-5

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See detailCarbon Supply and Photoacclimation Cross Talk in the Green Alga Chlamydomonas reinhardtii.
Polukhina, I; Fristedt, R; Dinc, E et al

in Plant Physiology (2016), 172(3), 1494-1505

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See detailThe peculiar NPQ regulation in the Pinguiphyte Phaeomonas challenge the xanthopyll cycle dogma
Berne, Nicolas ULiege; Bailleul, Benjamin; Cardol, Pierre ULiege

Poster (2016, August 05)

Photosynthetic organisms can experience fluctuating light conditions in their environment, and can develop different strategies to maintain a fine balance between light harvesting, photochemistry, and ... [more ▼]

Photosynthetic organisms can experience fluctuating light conditions in their environment, and can develop different strategies to maintain a fine balance between light harvesting, photochemistry, and protection from excess photon absorption. One of those strategies is the high energy state quenching (or qE, a component of the Non Photochemical Quenching) which consists in the dissipation of excess light energy in the form of heat in the photosystem II antenna. This mechanism is tightly related to the xanthophyll cycle, which consists in the reversible deepoxidation of some carotenoids: violaxanthin into zeaxanthin or diadinoxanthin into diatoxanthin/dinoxanthin. In the pinguiophyte Phaeomonas sp whose NPQ is strictly proportional tothe amount of zeaxanthin, the light regulation of this qE mechanism is very peculiar, displaying a very important quenching in the dark, which recovers under low to moderate light. This peculiar feature of the qE in Phaeomonas offers a unique opportunity to study the xanthophyll cycle, and to dissect its different regulators. We could show that, because of the existence of a transthylakoidal proton gradient in the dark, the deepoxydase is already active in the absence of a light-induced proton transport. At the contrary, the epoxidase activity was completely inactive in the dark, and slow under high light, but showed an optimum under low light conditions. [less ▲]

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See detailDissecting the peripheral stalk of the mitochondrial ATP synthase of chlorophycean algae.
Vázquez-Acevedo, M; Vega de Luna, F; Sánchez-Vásquez, L et al

in Biochimica et Biophysica Acta-Bioenergetics (2016), 1857(8), 1183-90

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See detailIsolation and characterization of mutants deficient in four steps of the phylloquinone biosynthesis pathway in Chlamydomonas reinhardtii.
Emonds-Alt, Barbara ULiege; Remacle, Claire ULiege; Cardol, Pierre ULiege

Poster (2016, April 26)

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in ... [more ▼]

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in Synechocystis sp. PCC 6803, involves 8 enzymatic steps from chorismate [1]. In the green alga Chlamydomonas reinhardtii, characterization of phylloquinone biosynthesis was still partial and only one mutant deficient for MEND was characterized [2]. In the present work, we found MENA-H homologs in C. reinhardtii genomic database. In particular, MENF, MEND, MENC, and MENH catalytic domains are present in a single ORF (named PHYLLO by similarity to gene organisation in Arabidopsis). We then took advantage of the fact that a double reduction of plastoquinone (PQ) in PQH2 occurs in anoxia into the A1 site in the mend mutant, interrupting photosynthetic electron transfer [3], to isolate new phylloquinone-deficient strains. UPLC-MS analysis confirmed the absence of phylloquinone in four news mutants impaired in MENA, MENB, MENC (PHYLLO) and MENE. Despite this loss, men mutants are still able to grow in low light but are high light-sensitive. In low light, the level of active PSII in men mutants is identical to that of the wild-type, but the level of active PSI is reduced by 30-40% as assayed by spectroscopic measurements. This decrease is more pronounced when cells are exposed to high light intensities during 4 hours. The level of active PSI is ~ 10% of wild-type cells and the electron photosynthetic transfer is reduced accordingly. Reorganization of the photosynthetic apparatus following lack of phylloquinone in men mutants is discussed. [less ▲]

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See detailIsolation and characterization of mutants deficient in four steps of the phylloquinone biosynthesis pathway in Chlamydomonas reinhardtii.
Emonds-Alt, Barbara ULiege; Remacle, Claire ULiege; Cardol, Pierre ULiege

Poster (2016, April 26)

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in ... [more ▼]

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in Synechocystis sp. PCC 6803, involves 8 enzymatic steps from chorismate [1]. In the green alga Chlamydomonas reinhardtii, characterization of phylloquinone biosynthesis was still partial and only one mutant deficient for MEND was characterized [2]. In the present work, we found MENA-H homologs in C. reinhardtii genomic database. In particular, MENF, MEND, MENC, and MENH catalytic domains are present in a single ORF (named PHYLLO by similarity to gene organisation in Arabidopsis). We then took advantage of the fact that a double reduction of plastoquinone (PQ) in PQH2 occurs in anoxia into the A1 site in the mend mutant, interrupting photosynthetic electron transfer [3], to isolate new phylloquinone-deficient strains. UPLC-MS analysis confirmed the absence of phylloquinone in four news mutants impaired in MENA, MENB, MENC (PHYLLO) and MENE. Despite this loss, men mutants are still able to grow in low light but are high light-sensitive. In low light, the level of active PSII in men mutants is identical to that of the wild-type, but the level of active PSI is reduced by 30-40% as assayed by spectroscopic measurements. This decrease is more pronounced when cells are exposed to high light intensities during 4 hours. The level of active PSI is ~ 10% of wild-type cells and the electron photosynthetic transfer is reduced accordingly. Reorganization of the photosynthetic apparatus following lack of phylloquinone in men mutants is discussed. [less ▲]

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See detailDissecting the peripheral stalk of the mitochondrial ATP synthase of chlorophycean algae
Vázquez-Acevedo, Miriam; Vega-deLuna, Félix; Sánchez-Vásquez, Lorenzo et al

in Biochimica et Biophysica Acta-Bioenergetics (2016), 1857(8), 1183-1190

The algae Chlamydomonas reinhardtii and Polytomella sp., a green and a colorless member of the chlorophycean lineage respectively, exhibit a highly-stable dimeric mitochondrial F1Fo-ATP synthase (complex ... [more ▼]

The algae Chlamydomonas reinhardtii and Polytomella sp., a green and a colorless member of the chlorophycean lineage respectively, exhibit a highly-stable dimeric mitochondrial F1Fo-ATP synthase (complex V), with a molecular mass of 1600kDa. Polytomella, lacking both chloroplasts and a cell wall, has greatly facilitated the purification of the algal ATP-synthase. Each monomer of the enzyme has 17 polypeptides, eight of which are the conserved, main functional components, and nine polypeptides (Asa1 to Asa9) unique to chlorophycean algae. These atypical subunits form the two robust peripheral stalks observed in the highly-stable dimer of the algal ATP synthase in several electron-microscopy studies. The topological disposition of the components of the enzyme has been addressed with cross-linking experiments in the isolated complex; generation of subcomplexes by limited dissociation of complex V; detection of subunit-subunit interactions using recombinant subunits; in vitro reconstitution of subcomplexes; silencing of the expression of Asa subunits; and modeling of the overall structural features of the complex by EM image reconstruction. Here, we report that the amphipathic polymer Amphipol A8-35 partially dissociates the enzyme, giving rise to two discrete dimeric subcomplexes, whose compositions were characterized. An updated model for the topological disposition of the 17 polypeptides that constitute the algal enzyme is suggested. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. [less ▲]

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See detailMeasurement of photosynthetic electron transfers by absorption spectroscopy
Cardol, Pierre ULiege

Conference (2016, January 27)

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See detailSubunit Asa1 spans all the peripheral stalk of the mitochondrial ATP synthase of the chlorophycean alga Polytomella sp.
Colina-Tenorio, Lilia; Miranda-Astudillo, Hector; Cano-Estrada, Araceli et al

in Biochimica et biophysica acta (2016)

Mitochondrial F1FO-ATP synthase of chlorophycean algae is dimeric. It contains eight orthodox subunits (alpha, beta, gamma, delta, epsilon, OSCP, a and c) and nine atypical subunits (Asa1 to 9). These ... [more ▼]

Mitochondrial F1FO-ATP synthase of chlorophycean algae is dimeric. It contains eight orthodox subunits (alpha, beta, gamma, delta, epsilon, OSCP, a and c) and nine atypical subunits (Asa1 to 9). These subunits build the peripheral stalk of the enzyme and stabilize its dimeric structure. The location of the 66.1kDa subunit Asa1 has been debated. On one hand, it was found in a transient subcomplex that contained membrane-bound subunits Asa1/Asa3/Asa5/Asa8/a (Atp6)/c (Atp9). On the other hand, Asa1 was proposed to form the bulky structure of the peripheral stalk that contacts the OSCP subunit in the F1 sector. Here, we overexpressed and purified the recombinant proteins Asa1 and OSCP and explored their interactions in vitro, using immunochemical techniques and affinity chromatography. Asa1 and OSCP interact strongly, and the carboxy-terminal half of OSCP seems to be instrumental for this association. In addition, the algal ATP synthase was partially dissociated at relatively high detergent concentrations, and an Asa1/Asa3/Asa5/Asa8/a/c10 subcomplex was identified. Furthermore, Far-Western analysis suggests an Asa1-Asa8 interaction. Based on these results, a model is proposed in which Asa1 spans the whole peripheral arm of the enzyme, from a region close to the matrix-exposed side of the mitochondrial inner membrane to the F1 region where OSCP is located. 3D models show elongated, helix-rich structures for chlorophycean Asa1 subunits. Asa1 subunit probably plays a scaffolding role in the peripheral stalk analogous to the one of subunit b in orthodox mitochondrial enzymes. [less ▲]

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