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Jean-pierre Blein - One of the best experts on this subject based on the ideXlab platform.
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the 1 45 a resolution structure of the cryptogein cholesterol complex a close up view of a sterol carrier protein scp active site
Acta Crystallographica Section D-biological Crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4122, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C2221, with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-β-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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The 1.45 A resolution structure of the cryptogein-cholesterol complex: a close-up view of a sterol carrier protein (SCP) active site.
Acta crystallographica. Section D Biological crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4(1)22, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C222(1), with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-beta-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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The fungal elicitor cryptogein is a sterol carrier protein.
FEBS Letters, 1997Co-Authors: Vladimír Mikeš, Marie-louise Milat, Michel Ponchet, Pierre Ricci, Jean-pierre BleinAbstract:Cryptogein is a protein secreted by the phytopathogenic pseudo-fungus, Phytophthora cryptogea. It is a basic 10 kDa hydrophilic protein having a hydrophobic pocket and three disulfide bridges. These common features with sterol carrier proteins led us to investigate its possible sterol transfer activity using the fluorescent sterol, dehydroergosterol. The results show that cryptogein has one binding site with strong affinity for dehydroergosterol. Moreover, this protein catalyzes the transfer of sterols between phospholipidic artificial membranes. This is the first evidence for the existence of an extracellular sterol carrier protein and for a molecular activity of cryptogein. This property should contribute to an understanding of the role of cryptogein in plant-microorganism interactions.
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Changes in lipid composition in tobacco cells treated with cryptogein, an elicitor from Phytophthora cryptogea
Plant Science, 1995Co-Authors: Eric Tavernier, Jean-pierre Blein, Veerle Stallaert, Alain PuginAbstract:Abstract Changes in lipid composition occurred when tobacco cells (Nicotiana tabacum var. Xanthi) were treated with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea. The most striking change was an increase in acylated steryl glycosides and steryl esters levels, certainly resulting from the glycosylation and/or esterification of free sterols. Moreover, in vivo pulse-labelling experiments with [14C]acetate also showed that a progressive decline in the incorporation rate of [14C]acetate into free sterols started with the induction of sesquiterpenoid synthesis and lasted when sesquiterpenoid synthesis stops. This phenomenon was accompanied by a significant increase in the synthesis rate of phosphatidylethanolamine occuring after a period of 12 h (80% of [14C]incorporated into lipids was found in PE). These pulse-labelling experiments also indicated a transient neosynthesis of high levels of acylated steryl glycosides and steryl esters in elicited cells. These results demonstrated that glycosylation and/or esterification of sterols (preexistent or neosynthetised) is an initial event among plant cell responses associated with the hypersensitive reaction.
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Protein Phosphorylation Is Induced in Tobacco Cells by the Elicitor Cryptogein
Plant Physiology, 1994Co-Authors: Marie-paute Viard, Pierre Ricci, Alain Pugin, Fabrice Martin, Jean-pierre BleinAbstract:Changes in plasmalemma ion fluxes were observed when tobacco (Nicotiana tabacum) cells were treated with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea. A strong alkalization of the culture medium, accompanied by a leakage of potassium, was induced within a few minutes of treatment. These effects reached a maximum after 30 to 40 min and lasted for several hours. This treatment also resulted in a rapid, but transient, production of activated oxygen species. All these physiological responses were fully sensitive to staurosporine, a known protein kinase inhibitor. Furthermore, a study of protein phosphorylation showed that cryptogein induced a staurosporine-sensitive phosphorylation of several polypeptides. These data suggest that phosphorylated proteins may be essential for the transduction of elicitor signals.
Thierry Prange - One of the best experts on this subject based on the ideXlab platform.
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the 1 45 a resolution structure of the cryptogein cholesterol complex a close up view of a sterol carrier protein scp active site
Acta Crystallographica Section D-biological Crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4122, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C2221, with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-β-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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The 1.45 A resolution structure of the cryptogein-cholesterol complex: a close-up view of a sterol carrier protein (SCP) active site.
Acta crystallographica. Section D Biological crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4(1)22, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C222(1), with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-beta-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
Marie-louise Milat - One of the best experts on this subject based on the ideXlab platform.
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the 1 45 a resolution structure of the cryptogein cholesterol complex a close up view of a sterol carrier protein scp active site
Acta Crystallographica Section D-biological Crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4122, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C2221, with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-β-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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The 1.45 A resolution structure of the cryptogein-cholesterol complex: a close-up view of a sterol carrier protein (SCP) active site.
Acta crystallographica. Section D Biological crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4(1)22, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C222(1), with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-beta-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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The fungal elicitor cryptogein is a sterol carrier protein.
FEBS Letters, 1997Co-Authors: Vladimír Mikeš, Marie-louise Milat, Michel Ponchet, Pierre Ricci, Jean-pierre BleinAbstract:Cryptogein is a protein secreted by the phytopathogenic pseudo-fungus, Phytophthora cryptogea. It is a basic 10 kDa hydrophilic protein having a hydrophobic pocket and three disulfide bridges. These common features with sterol carrier proteins led us to investigate its possible sterol transfer activity using the fluorescent sterol, dehydroergosterol. The results show that cryptogein has one binding site with strong affinity for dehydroergosterol. Moreover, this protein catalyzes the transfer of sterols between phospholipidic artificial membranes. This is the first evidence for the existence of an extracellular sterol carrier protein and for a molecular activity of cryptogein. This property should contribute to an understanding of the role of cryptogein in plant-microorganism interactions.
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Responses of Cultured Tobacco Cells to Cryptogein, a Proteinaceous Elicitor from Phytophthora cryptogea: Possible Plasmalemma Involvement.
Plant Physiology, 1991Co-Authors: Jean-pierre Blein, Marie-louise Milat, Pierre RicciAbstract:In culture, the phytopathogenic fungus Phytophthora cryptogea secretes a protein which elicits hypersensitive-like necroses and protects tobacco plants against invasion by the pathogen Phytophthora parasitica var. nicotianae. This protein, named cryptogein, has been purified and its amino acid sequence determined. In this work, we studied the effect of cryptogein on tobacco cell suspension cultures. Cryptogein was lethal at about 0.10 micromolar. When added at sublethal doses, it elicited the production of ethylene and phytoalexins. It also induced a rapid increase in pH and conductivity of the extracellular medium without affecting the integrity of the plasma membrane. Cryptogein reduced the fusicoccin-induced acidification of the extracellular medium. The concentration which inhibited the fusicoccin response by 50% was 0.8 nanomolar, while 1 micromolar erythrosine B, an ATPase inhibitor, was needed to produce the same inhibition. However, cryptogein did not inhibit the activity of a purified plasma membrane ATPase. Results of binding studies with whole cells suggested the presence of elicitor-binding sites with a high affinity for cryptogein. The involvement of the plasma membrane during the initial interaction between elicitor and cells is discussed.
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Capsidiol and ethylene production by tobacco cells in response to cryptogein, an elicitor from Phytophthora cryptogea
Phytochemistry, 1991Co-Authors: Marie-louise Milat, Pierre Ricci, Philippe Bonnet, Jean-pierre BleinAbstract:Abstract Tobacco cells treated with cryptogein, an extracellular protein produced by Phytophthora cryptogea, accumulated ethylene and sesquiterpenoid compounds, mainly capsidiol. This protein, which causes hypersensitive-like necroses and ultimately makes tobacco resistant to the pathogen P. parasitica var. nicotianae is, therefore, an elicitor of defence mechanisms.
Monica Höfte - One of the best experts on this subject based on the ideXlab platform.
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control of Phytophthora cryptogea in the hydroponic forcing of witloof chicory with the rhamnolipid based biosurfactant formulation pro1
Plant Pathology, 2005Co-Authors: K. De Jonghe, I. De Dobbelaere, Rob Sarrazyn, Monica HöfteAbstract:Rhamnolipids, extracellular metabolites of Pseudomonas aeruginosa with surfactant properties, proved to be very effective in controlling the spread of brown root rot disease caused by Phytophthora cryptogea in the hydroponic forcing system of witloof chicory (Cichorium intybus var. foliosum). The biosurfactant was applied as the product PRO1, a formulation of 25% rhamnolipids in oil. Both an in vitro screening and in vivo experiments in a mini-hydroponic system demonstrated the ability of PRO1 to control brown root rot. A 25 µg mL−1 rhamnolipids nutrient solution was enough to obtain good control of an artificial infection with a zoospore suspension of P. cryptogea. The biosurfactant PRO1 performed well in a semicommercial system under growers’ conditions. A treatment of 25 µg mL−1 rhamnolipids (100 µg mL−1 PRO1) reduced the disease incidence significantly in two independent experiments. However, PRO1 was not effective when a mycelial suspension was used as inoculum. Rhamnolipids have good potential to limit the spread of P. cryptogea in the hydroponic forcing system of witloof chicory, and can be used as a preventive measure against brown root rot.
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Control of Phytophthora cryptogea in the hydroponic forcing of witloof chicory with the rhamnolipid‐based biosurfactant formulation PRO1
Plant Pathology, 2005Co-Authors: K. De Jonghe, I. De Dobbelaere, Rob Sarrazyn, Monica HöfteAbstract:Rhamnolipids, extracellular metabolites of Pseudomonas aeruginosa with surfactant properties, proved to be very effective in controlling the spread of brown root rot disease caused by Phytophthora cryptogea in the hydroponic forcing system of witloof chicory (Cichorium intybus var. foliosum). The biosurfactant was applied as the product PRO1, a formulation of 25% rhamnolipids in oil. Both an in vitro screening and in vivo experiments in a mini-hydroponic system demonstrated the ability of PRO1 to control brown root rot. A 25 µg mL−1 rhamnolipids nutrient solution was enough to obtain good control of an artificial infection with a zoospore suspension of P. cryptogea. The biosurfactant PRO1 performed well in a semicommercial system under growers’ conditions. A treatment of 25 µg mL−1 rhamnolipids (100 µg mL−1 PRO1) reduced the disease incidence significantly in two independent experiments. However, PRO1 was not effective when a mycelial suspension was used as inoculum. Rhamnolipids have good potential to limit the spread of P. cryptogea in the hydroponic forcing system of witloof chicory, and can be used as a preventive measure against brown root rot.
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Control of brown root rot caused by Phytophthora cryptogea in the hydroponic forcing of witloof chicory (Cichorium intybus var. foliosum) by means of a nonionic surfactant
Crop Protection, 2005Co-Authors: Kris De Jonghe, Rob Sarrazyn, Isabelle De Dobbelaere, Monica HöfteAbstract:Abstract The surfactant Atplus MBA1301, a monobranched C13 alcohol alkoxylate, was tested for its efficacy to control brown root rot, caused by the zoosporic pathogen Phytophthora cryptogea in the hydroponic crop production (forcing) of witloof chicory. In in vitro experiments, 4 μg ml −1 Atplus MBA1301 inhibited sporangia development, while motile zoospores of P. cryptogea ceased motility and lysed within 1 min upon exposure to 10 μg ml −1 surfactant. When the pathogen was artificially introduced in pot assays or in a mini hydroponic system using a mycelial suspension and/or zoospores as an inoculum, a concentration of 10 μg Atplus MBA1301 ml −1 nutrient solution was sufficient to obtain a good control. Root hair development appeared to be negatively correlated with disease incidence and disease severity and can be used to monitor the brown root rot disease in a nondestructive way. The surfactant Atplus MBA1301 was also tested in a commercial setting under growers’ conditions. Organically grown witloof chicory roots of the cultivar Vintor were artificially infected with 10 2 zoospores ml −1 . A disease incidence of 90.8% was recorded in the infected control. Only 1.3% of the roots showed symptoms in a treatment with 10 μg ml −1 Atplus MBA1301. This is not significantly different from the healthy control, which remained free of symptoms. It can be concluded that Atplus MBA1301 has excellent potential to control Phytophthora brown root rot in witloof chicory hydroponic forcing.
Michel Ponchet - One of the best experts on this subject based on the ideXlab platform.
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the 1 45 a resolution structure of the cryptogein cholesterol complex a close up view of a sterol carrier protein scp active site
Acta Crystallographica Section D-biological Crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4122, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C2221, with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-β-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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The 1.45 A resolution structure of the cryptogein-cholesterol complex: a close-up view of a sterol carrier protein (SCP) active site.
Acta crystallographica. Section D Biological crystallography, 2002Co-Authors: Marie Bernard Lascombe, Marie-louise Milat, Michel Ponchet, Jean-pierre Blein, Paul Venard, Thierry PrangeAbstract:Cryptogein is a small 10 kDa elicitor produced by the phytoparasitic oomycete Phytophthora cryptogea. The protein also displays a sterol carrier activity. The native protein crystallizes in space group P4(1)22, with unit-cell parameters a = b = 46.51, c = 134.9 A (diffraction limit: 2.1 A). Its complex with cholesterol crystallizes in space group C222(1), with unit-cell parameters a = 30.96, b = 94.8, c = 65.3 A and a resolution enhanced to 1.45 A. The large inner non-specific hydrophobic cavity is able to accommodate a large variety of 3-beta-hydroxy sterols. Cryptogein probably acts as a sterol shuttle helping the pathogen to grow and complete its life cycle.
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Heterologous expression of a basic elicitin from Phytophthora cryptogea in Phytophthora infestans increases its ability to cause leaf necrosis in tobacco
Microbiology, 1998Co-Authors: Franck Panabières, Michel Ponchet, Pierre Ricci, Paul R. J. Birch, Shiela E. Unkles, Isabelle Lacourt, Paul Venard, Harald Keller, Valérie Allasia, James M. DuncanAbstract:Summary: The cry-b sequence, encoding a basic elicitin (cryptogein B) from Phytophthora cryptogea, was co-transformed into Phytophthora infestans. The copy number of the cry-b sequence varied in co-transformants. Nevertheless, in all cases the alien elicitin gene was transcribed, translated and the protein secreted in vitro from such transformants. Moreover, the secreted cryptogein B from P. infestans co-transformants increased their ability to cause a hypersensitive-response-like necrosis of tobacco leaves. It was thus concluded that the transfer of a single gene encoding a basic elicitin from one Phytophthora species to another can dramatically alter the phenotypic interaction of the transformed species with tobacco.
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The fungal elicitor cryptogein is a sterol carrier protein.
FEBS Letters, 1997Co-Authors: Vladimír Mikeš, Marie-louise Milat, Michel Ponchet, Pierre Ricci, Jean-pierre BleinAbstract:Cryptogein is a protein secreted by the phytopathogenic pseudo-fungus, Phytophthora cryptogea. It is a basic 10 kDa hydrophilic protein having a hydrophobic pocket and three disulfide bridges. These common features with sterol carrier proteins led us to investigate its possible sterol transfer activity using the fluorescent sterol, dehydroergosterol. The results show that cryptogein has one binding site with strong affinity for dehydroergosterol. Moreover, this protein catalyzes the transfer of sterols between phospholipidic artificial membranes. This is the first evidence for the existence of an extracellular sterol carrier protein and for a molecular activity of cryptogein. This property should contribute to an understanding of the role of cryptogein in plant-microorganism interactions.
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Occurrence of multiple forms of elicitins in Phytophthora cryptogea
Plant Physiology and Biochemistry, 1994Co-Authors: J.-y.k Le Berre, Michel Ponchet, Philippe Bonnet, Franck Panabières, L. Denoroy, Antoine Marais, Pierre RicciAbstract:The phytopathogenic fungus Phytophthora cryptogea produces large amounts of cryptogein, a proteinaceous elicitor of active defences in tobacco, which induces a hypersensitive-like response and acquired resistance to the compatible pathogen Phytophthora parasitica var. nicotinae. We found that P. cryptogea actually synthesizes at least three isoforms of cryptogein, differing by their pI. These three isoforms were purified and were tested on tobacco. The major form is a basic protein, cryptogein B, which was identified to the previously described cryptogein. The two other forms, A1 and A2, are acidic and resemble other acidic elicitins already characterized, by their behaviour in electrophoresis, their amino-acid sequence and by their ability to induce resistance in tobacco plants with limited or no phytotoxic symptoms