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Jan Schirawski - One of the best experts on this subject based on the ideXlab platform.
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the Tryptophan Aminotransferase tam1 catalyses the single biosynthetic step for Tryptophan dependent pigment synthesis in ustilago maydis
Molecular Microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
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The Tryptophan Aminotransferase Tam1 catalyses the single biosynthetic step for Tryptophan‐dependent pigment synthesis in Ustilago maydis
Molecular microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
Peter Mayser - One of the best experts on this subject based on the ideXlab platform.
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characterization of Tryptophan Aminotransferase 1 of malassezia furfur the key enzyme in the production of indolic compounds by m furfur
Experimental Dermatology, 2013Co-Authors: Janina Preuss, Wiebke Hort, Sarah Lang, Anette Netsch, Stefan Rahlfs, Gunter Lochnit, Esther Jortzik, Katja Becker, Peter MayserAbstract:Malassezia yeasts are responsible for the widely distributed skin disease Pityriasis versicolor (PV), which is characterized by a hyper- or hypopigmentation of affected skin areas. For Malassezia furfur, it has been shown that pigment production relies on Tryptophan metabolism. A Tryptophan Aminotransferase was found to catalyse the initial catalytic step in pigment formation in the model organism Ustilago maydis. Here, we describe the sequence determination, recombinant production and biochemical characterization of Tryptophan Aminotransferase MfTam1 from M. furfur. The enzyme catalyses the transamination from l-Tryptophan to keto acids such as α-ketoglutarate with Km values for both substrates in the low millimolar range. Furthermore, MfTam1 presents a temperature optimum at 40°C and a pH optimum at 8.0. MfTam1 activity is highly dependent on pyridoxal phosphate (PLP), whereas compounds interfering with PLP, such as cycloserine (CS) and aminooxyacetate, inhibit the MfTam1 reaction. CS is known to reverse hyperpigmentation in PV. Thus, the results of the present study give a deeper insight into the role of MfTam1 in PV pathogenesis and as potential target for the development of novel PV therapeutics.
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the Tryptophan Aminotransferase tam1 catalyses the single biosynthetic step for Tryptophan dependent pigment synthesis in ustilago maydis
Molecular Microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
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The Tryptophan Aminotransferase Tam1 catalyses the single biosynthetic step for Tryptophan‐dependent pigment synthesis in Ustilago maydis
Molecular microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
Katja Zuther - One of the best experts on this subject based on the ideXlab platform.
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the Tryptophan Aminotransferase tam1 catalyses the single biosynthetic step for Tryptophan dependent pigment synthesis in ustilago maydis
Molecular Microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
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The Tryptophan Aminotransferase Tam1 catalyses the single biosynthetic step for Tryptophan‐dependent pigment synthesis in Ustilago maydis
Molecular microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
Jose M Alonso - One of the best experts on this subject based on the ideXlab platform.
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The Arabidopsis YUCCA1 Flavin Monooxygenase Functions in the Indole-3-Pyruvic Acid Branch of Auxin Biosynthesis
The Plant cell, 2011Co-Authors: Anna Stepanova, Karin Ljung, Jeonga Yun, Linda M. Robles, Ondřej Novák, Hongwei Guo, Jose M AlonsoAbstract:The effects of auxins on plant growth and development have been known for more than 100 years, yet our understanding of how plants synthesize this essential plant hormone is still fragmentary at best. Gene loss- and gain-of-function studies have conclusively implicated three gene families, CYTOCHROME P450 79B2/B3 (CYP79B2/B3), YUCCA (YUC), and Tryptophan Aminotransferase OF ARABIDOPSIS1/Tryptophan Aminotransferase-RELATED (TAA1/TAR), in the production of this hormone in the reference plant Arabidopsis thaliana. Each of these three gene families is believed to represent independent routes of auxin biosynthesis. Using a combination of pharmacological, genetic, and biochemical approaches, we examined the possible relationships between the auxin biosynthetic pathways defined by these three gene families. Our findings clearly indicate that TAA1/TARs and YUCs function in a common linear biosynthetic pathway that is genetically distinct from the CYP79B2/B3 route. In the redefined TAA1-YUC auxin biosynthetic pathway, TAA1/TARs are required for the production of indole-3-pyruvic acid (IPyA) from Trp, whereas YUCs are likely to function downstream. These results, together with the extensive genetic analysis of four pyruvate decarboxylases, the putative downstream components of the TAA1 pathway, strongly suggest that the enzymatic reactions involved in indole-3-acetic acid (IAA) production via IPyA are different than those previously postulated, and a new and testable model for how IAA is produced in plants is needed.
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the arabidopsis yucca1 flavin monooxygenase functions in the indole 3 pyruvic acid branch of auxin biosynthesis
The Plant Cell, 2011Co-Authors: Anna N Stepanova, Linda Robles, Ondrej Novak, Wenrong He, Karin Ljung, Jose M AlonsoAbstract:The effects of auxins on plant growth and development have been known for more than 100 years, yet our understanding of how plants synthesize this essential plant hormone is still fragmentary at best. Gene loss- and gain-of-function studies have conclusively implicated three gene families, CYTOCHROME P450 79B2/B3 (CYP79B2/B3), YUCCA (YUC), and Tryptophan Aminotransferase OF ARABIDOPSIS1/Tryptophan Aminotransferase-RELATED (TAA1/TAR), in the production of this hormone in the reference plant Arabidopsis thaliana. Each of these three gene families is believed to represent independent routes of auxin biosynthesis. Using a combination of pharmacological, genetic, and biochemical approaches, we examined the possible relationships between the auxin biosynthetic pathways defined by these three gene families. Our findings clearly indicate that TAA1/TARs and YUCs function in a common linear biosynthetic pathway that is genetically distinct from the CYP79B2/B3 route. In the redefined TAA1-YUC auxin biosynthetic pathway, TAA1/TARs are required for the production of indole-3-pyruvic acid (IPyA) from Trp, whereas YUCs are likely to function downstream. These results, together with the extensive genetic analysis of four pyruvate decarboxylases, the putative downstream components of the TAA1 pathway, strongly suggest that the enzymatic reactions involved in indole-3-acetic acid (IAA) production via IPyA are different than those previously postulated, and a new and testable model for how IAA is produced in plants is needed.
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taa1 mediated auxin biosynthesis is essential for hormone crosstalk and plant development
Cell, 2008Co-Authors: Anna Stepanova, Joyce Robertsonhoyt, Larissa M Benavente, Karel Doležal, Alexandra Schlereth, Gerd Jurgens, Jose M AlonsoAbstract:Plants have evolved a tremendous ability to respond to environmental changes by adapting their growth and development. The interaction between hormonal and developmental signals is a critical mechanism in the generation of this enormous plasticity. A good example is the response to the hormone ethylene that depends on tissue type, developmental stage, and environmental conditions. By characterizing the Arabidopsis wei8 mutant, we have found that a small family of genes mediates tissue-specific responses to ethylene. Biochemical studies revealed that WEI8 encodes a long-anticipated Tryptophan Aminotransferase, TAA1, in the essential, yet genetically uncharacterized, indole-3-pyruvic acid (IPA) branch of the auxin biosynthetic pathway. Analysis of TAA1 and its paralogues revealed a link between local auxin production, tissue-specific ethylene effects, and organ development. Thus, the IPA route of auxin production is key to generating robust auxin gradients in response to environmental and developmental cues.
Bernhard L J Kindler - One of the best experts on this subject based on the ideXlab platform.
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the Tryptophan Aminotransferase tam1 catalyses the single biosynthetic step for Tryptophan dependent pigment synthesis in ustilago maydis
Molecular Microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
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The Tryptophan Aminotransferase Tam1 catalyses the single biosynthetic step for Tryptophan‐dependent pigment synthesis in Ustilago maydis
Molecular microbiology, 2008Co-Authors: Katja Zuther, Peter Mayser, Ursula Hettwer, Peter Spiteller, Bernhard L J Kindler, Petr Karlovsky, Christoph W Basse, Jan SchirawskiAbstract:Tryptophan is a precursor for many biologically active secondary metabolites. We have investigated the origin of indole pigments first described in the pityriasis versicolor-associated fungus Malassezia furfur. Some of the identified indole pigments have properties potentially explaining characteristics of the disease. As M. furfur is not amenable to genetic manipulation, we used Ustilago maydis to investigate the pathway leading to pigment production from Tryptophan. We show by high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance analysis that the compounds produced by U. maydis include those putatively involved in the etiology of pityriasis versicolor. Using a reverse genetics approach, we demonstrate that the Tryptophan Aminotransferase Tam1 catalyses pigment biosynthesis by conversion of Tryptophan into indolepyruvate. A forward genetics approach led to the identification of mutants incapable of producing the pigments. These mutants were affected in the sir1 gene, presumably encoding a sulphite reductase. In vitro experiments with purified Tam1 showed that 2-oxo 4-methylthio butanoate serves as a substrate linking Tryptophan deamination to sulphur metabolism. We provide the first direct evidence that these indole pigments form spontaneously from indolepyruvate and Tryptophan without any enzymatic activity. This suggests that compounds with a proposed function in M. furfur-associated disease consist of indolepyruvate-derived spontaneously generated metabolic by-products.
