François Perreau
Agro ParisTech
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Featured researches published by François Perreau.
Journal of Biological Chemistry | 2010
Adjélé Wilson; James N. Kinney; Petrus H. Zwart; Claire Punginelli; Sandrine D'Haene; François Perreau; Michael G. Klein; Diana Kirilovsky; Cheryl A. Kerfeld
The photoprotective processes of photosynthetic organisms involve the dissipation of excess absorbed light energy as heat. Photoprotection in cyanobacteria is mechanistically distinct from that in plants; it involves the orange carotenoid protein (OCP), a water-soluble protein containing a single carotenoid. The OCP is a new member of the family of blue light-photoactive proteins; blue-green light triggers the OCP-mediated photoprotective response. Here we report structural and functional characterization of the wild type and two mutant forms of the OCP, from the model organism Synechocystis PCC6803. The structural analysis provides high resolution detail of the carotenoid-protein interactions that underlie the optical properties of the OCP, unique among carotenoid-proteins in binding a single pigment per polypeptide chain. Collectively, these data implicate several key amino acids in the function of the OCP and reveal that the photoconversion and photoprotective responses of the OCP to blue-green light can be decoupled.
Plant Journal | 2012
Anne Frey; Delphine Effroy; Valérie Lefebvre; Mitsunori Seo; François Perreau; Adeline Berger; Julien Sechet; Alexandra To; Helen M. North; Annie Marion-Poll
Carotenoid cleavage, catalyzed by the 9-cis-epoxycarotenoid dioxygenase (NCED) constitutes a key step in the regulation of ABA biosynthesis. In Arabidopsis, this enzyme is encoded by five genes. NCED3 has been shown to play a major role in the regulation of ABA synthesis in response to water deficit, whereas NCED6 and NCED9 have been shown to be essential for the ABA production in the embryo and endosperm that imposes dormancy. Reporter gene analysis was carried out to determine the spatiotemporal pattern of NCED5 and NCED9 gene expression. GUS activity from the NCED5 promoter was detected in both the embryo and endosperm of developing seeds with maximal staining after mid-development. NCED9 expression was found at early stages in the testa outer integument layer 1, and after mid-development in epidermal cells of the embryo, but not in the endosperm. In accordance with its temporal- and tissue-specific expression, the phenotypic analysis of nced5 nced6 nced9 triple mutant showed the involvement of the NCED5 gene, together with NCED6 and NCED9, in the induction of seed dormancy. In contrast to nced6 and nced9, however, nced5 mutation did not affect the gibberellin required for germination. In vegetative tissues, combining nced5 and nced3 mutations reduced vegetative growth, increased water loss upon dehydration, and decreased ABA levels under both normal and stressed conditions, as compared with nced3. NCED5 thus contributes, together with NCED3, to ABA production affecting plant growth and water stress tolerance.
Science | 2015
Ryan L. Leverenz; Markus Sutter; Adjélé Wilson; Sayan Gupta; Adrien Thurotte; Céline Bourcier de Carbon; Christopher J. Petzold; Corie Ralston; François Perreau; Diana Kirilovsky; Cheryl A. Kerfeld
Protection from too much light Photosynthetic organisms protect themselves from too much light using pigment photoswitches that absorb excess energy. Leverenz et al. analyzed the structure of an active, energy-dissipating form of the orange carotenoid protein (OCP) from a cyanobacterium. When activated by excess light, OCP moves its hydrophobic carotenoid pigment 12 Å within the protein to accommodate nonphotochemical quenching by the broader photosynthetic antenna complex. Science, this issue p. 1463 Large-scale pigment movement accompanies photoactivation of the orange carotenoid protein. Pigment-protein and pigment-pigment interactions are of fundamental importance to the light-harvesting and photoprotective functions essential to oxygenic photosynthesis. The orange carotenoid protein (OCP) functions as both a sensor of light and effector of photoprotective energy dissipation in cyanobacteria. We report the atomic-resolution structure of an active form of the OCP consisting of the N-terminal domain and a single noncovalently bound carotenoid pigment. The crystal structure, combined with additional solution-state structural data, reveals that OCP photoactivation is accompanied by a 12 angstrom translocation of the pigment within the protein and a reconfiguration of carotenoid-protein interactions. Our results identify the origin of the photochromic changes in the OCP triggered by light and reveal the structural determinants required for interaction with the light-harvesting antenna during photoprotection.
Biochimica et Biophysica Acta | 2011
Adjélé Wilson; Claire Punginelli; Mohea Couturier; François Perreau; Diana Kirilovsky
Photosynthetic organisms have developed photoprotective mechanisms to protect themselves from lethal high light intensities. One of these mechanisms involves the dissipation of excess absorbed light energy into heat. In cyanobacteria, light activation of a soluble carotenoid protein, the Orange Carotenoid Protein (OCP), binding a keto carotenoid, is the key inducer of this mechanism. Blue-green light absorption triggers structural changes within the carotenoid and the protein, leading to the conversion of a dark orange form into a red active form. Here we report the role in photoconversion and photoprotection of individual conserved tyrosines and tryptophans surrounding the rings of the carotenoid. Our results demonstrate that the interaction between the keto group of the carotenoid and Tyr201 and Trp288 is essential for OCP photoactivity. In addition, these amino acids are responsible for carotenoid affinity and specificity. We have already demonstrated that the aromatic character of Tyr44 and Trp110 interacting with the hydroxyl ring is critical. Here we show that the replacement of Tyr44 by Ser affects the stability of the red form avoiding its accumulation at any temperature, while Trp110Ser is affected in the energy necessary to the orange to red conversion and in the interaction with the antenna. Collectively our data support the idea that the red form is essential for photoprotection but not sufficient. Specific conformational changes occurring in the protein seem to be critical to the events leading to energy dissipation.
The Plant Cell | 2014
Arezki Sedoud; Rocío López-Igual; Ateeq Ur Rehman; Adjélé Wilson; François Perreau; Clémence Boulay; Imre Vass; Anja Krieger-Liszkay; Diana Kirilovsky
This work shows that the cyanobacterial photoactive orange carotenoid protein (OCP) protects Synechocystis cells from photoinhibition even under conditions in which it is unable to quench excess energy absorbed by phycobilisomes. OCP plays a dual role under light stress conditions, protecting cells against photooxidative stress by quenching excess energy and singlet oxygen. Cyanobacteria have developed a photoprotective mechanism that decreases the energy arriving at the photosynthetic reaction centers under high-light conditions. The photoactive orange carotenoid protein (OCP) is essential in this mechanism as a light sensor and energy quencher. When OCP is photoactivated by strong blue-green light, it is able to dissipate excess energy as heat by interacting with phycobilisomes. As a consequence, charge separation and recombination leading to the formation of singlet oxygen diminishes. Here, we demonstrate that OCP has another essential role. We observed that OCP also protects Synechocystis cells from strong orange-red light, a condition in which OCP is not photoactivated. We first showed that this photoprotection is related to a decrease of singlet oxygen concentration due to OCP action. Then, we demonstrated that, in vitro, OCP is a very good singlet oxygen quencher. By contrast, another carotenoid protein having a high similarity with the N-terminal domain of OCP is not more efficient as a singlet oxygen quencher than a protein without carotenoid. Although OCP is a soluble protein, it is able to quench the singlet oxygen generated in the thylakoid membranes. Thus, OCP has dual and complementary photoprotective functions as an energy quencher and a singlet oxygen quencher.
Plant Journal | 2013
Nicolas Denancé; Philippe Ranocha; Nicolas Oria; Xavier Barlet; Marie-Pierre Rivière; Koste A. Yadeta; Laurent Hoffmann; François Perreau; Gilles Clément; Alessandra Maia-Grondard; Grardy C. M. van den Berg; Bruno Savelli; Sylvie Fournier; Yann Aubert; Sandra Pelletier; Bart P. H. J. Thomma; Antonio Molina; Lise Jouanin; Yves Marco; Deborah Goffner
Inactivation of Arabidopsis WAT1 (Walls Are Thin1), a gene required for secondary cell-wall deposition, conferred broad-spectrum resistance to vascular pathogens, including the bacteria Ralstonia solanacearum and Xanthomonas campestris pv. campestris, and the fungi Verticillium dahliae and Verticillium albo-atrum. Introduction of NahG, the bacterial salicylic acid (SA)-degrading salicylate hydroxylase gene, into the wat1 mutant restored full susceptibility to both R. solanacearum and X. campestris pv. campestris. Moreover, SA content was constitutively higher in wat1 roots, further supporting a role for SA in wat1-mediated resistance to vascular pathogens. By combining transcriptomic and metabolomic data, we demonstrated a general repression of indole metabolism in wat1-1 roots as shown by constitutive down-regulation of several genes encoding proteins of the indole glucosinolate biosynthetic pathway and reduced amounts of tryptophan (Trp), indole-3-acetic acid and neoglucobrassicin, the major form of indole glucosinolate in roots. Furthermore, the susceptibility of the wat1 mutant to R. solanacearum was partially restored when crossed with either the trp5 mutant, an over-accumulator of Trp, or Pro35S:AFB1-myc, in which indole-3-acetic acid signaling is constitutively activated. Our original hypothesis placed cell-wall modifications at the heart of the wat1 resistance phenotype. However, the results presented here suggest a mechanism involving root-localized metabolic channeling away from indole metabolites to SA as a central feature of wat1 resistance to R. solanacearum.
Aquatic Toxicology | 2009
Rémy D. Tadonléké; Brigitte Leberre; François Perreau; Jean-François Humbert
The direct effects of pesticides on aquatic bacteria are poorly known. We experimentally investigated the direct effects of diuron (herbicide) on the composition and activities of lake bacterioplankton, using Denaturing Gradient Gel Electrophoresis (DGGE), cloning/sequencing, and flow cytometry with dyes that allow detection of dead cells, cells with depolarized membranes and cells with esterase activity (for physiological state). Generally, diuron had negative impacts on bacterial viability and abundance. Bacterial production strongly correlated with ammonium in controls, but not in diuron-treated samples. Moreover the increase in nitrate concentration with the proportion of dead bacteria was significantly higher in controls, providing evidence not previously shown for natural communities, that diuron may alter the mineralization of organic matter and nitrification. A picocyanobacteria and members of the family Flavobacteriaceae, known to degrade complex polymeric organic matter in aquatic systems were negatively affected by diuron. Except that, the DGGE banding patterns in controls and in polluted samples were generally similar, suggesting no perceptible susceptibility of major bacterial groups, and contrasting with previous reports that diuron has a strong impact on bacterial community composition. Our data suggest that diuron may affect functioning of aquatic systems through negative impacts on some bacterial phylotypes and bacterial cycling of nitrogen.
Analytical and Bioanalytical Chemistry | 2008
Aline Ghanem; Philippe Bados; François Perreau; Rachid Benabdallah; Cécile Plagellat; Luiz Felippe De Alencastro; Jacques Einhorn
A multiresidue method has been developed to analyze atrazine (ATZ), diuron (DIU), and their major degradation products, desethylatrazine (DEA), desisopropylatrazine (DIA), and dichlorophenylmethylurea in sewage sludge. Liquid chromatography coupled to electrospray tandem mass spectrometry (LC–ESI-MS–MS) allowed, in the multiple-reaction monitoring mode, the simultaneous analysis of these pesticides in only one run after their extraction with ethyl acetate–dichloromethane 90:10 (v/v) and a cleanup on a Florisil column. Stable isotopically labeled ATZ and DIU were used as internal standards to overcome matrix effects during the pesticide quantification. Using fortified samples, the method gave rise to 86–115% as mean recovery values depending on the analyte. Limits of detection (LODs) and of quantification (LOQs) ranging from 0.3 (DIA) to 1.5 (DEA) μg kg−1 dw and from 0.4 (DIA) to 2.0 (DEA) μg kg−1 dw, respectively, were sufficient to achieve the monitoring of these molecules in sludge from wastewater treatment plants of the Ile-de-France region.
Scientific Reports | 2015
Céline Bourcier de Carbon; Adrien Thurotte; Adjélé Wilson; François Perreau; Diana Kirilovsky
Carotenoids are widely distributed natural pigments that are excellent antioxidants acting in photoprotection. They are typically solubilized in membranes or attached to proteins. In cyanobacteria, the photoactive soluble Orange Carotenoid Protein (OCP) is involved in photoprotective mechanisms as a highly active singlet oxygen and excitation energy quencher. Here we describe a method for producing large amounts of holo-OCP in E.coli. The six different genes involved in the synthesis of holo-OCP were introduced into E. coli using three different plasmids. The choice of promoters and the order of gene induction were important: the induction of genes involved in carotenoid synthesis must precede the induction of the ocp gene in order to obtain holo-OCPs. Active holo-OCPs with primary structures derived from several cyanobacterial strains and containing different carotenoids were isolated. This approach for rapid heterologous synthesis of large quantities of carotenoproteins is a fundamental advance in the production of antioxidants of great interest to the pharmaceutical and cosmetic industries.
Plant Physiology | 2016
Rocío López-Igual; Adjélé Wilson; Ryan L. Leverenz; Matthew R. Melnicki; Céline Bourcier de Carbon; Markus Sutter; Aiko Turmo; François Perreau; Cheryl A. Kerfeld; Diana Kirilovsky
The N-terminal domains of the four Orange Carotenoid Protein isoforms defines distinct functions. The photoactive Orange Carotenoid Protein (OCP) is involved in cyanobacterial photoprotection. Its N-terminal domain (NTD) is responsible for interaction with the antenna and induction of excitation energy quenching, while the C-terminal domain is the regulatory domain that senses light and induces photoactivation. In most nitrogen-fixing cyanobacterial strains, there are one to four paralogous genes coding for homologs to the NTD of the OCP. The functions of these proteins are unknown. Here, we study the expression, localization, and function of these genes in Anabaena sp. PCC 7120. We show that the four genes present in the genome are expressed in both vegetative cells and heterocysts but do not seem to have an essential role in heterocyst formation. This study establishes that all four Anabaena NTD-like proteins can bind a carotenoid and the different paralogs have distinct functions. Surprisingly, only one paralog (All4941) was able to interact with the antenna and to induce permanent thermal energy dissipation. Two of the other Anabaena paralogs (All3221 and Alr4783) were shown to be very good singlet oxygen quenchers. The fourth paralog (All1123) does not seem to be involved in photoprotection. Structural homology modeling allowed us to propose specific features responsible for the different functions of these soluble carotenoid-binding proteins.