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Lucien Bettendorff - One of the best experts on this subject based on the ideXlab platform.
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Thiamine Triphosphate: a ubiquitous molecule in search of a physiological role
Metabolic Brain Disease, 2014Co-Authors: Lucien Bettendorff, Bernard Lakaye, Gregory Kohn, Pierre WinsAbstract:Thiamine Triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a more general role but this remains undefined. In contrast to Thiamine diphosphate (ThDP), ThTP is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. Though it was long thought that ThTP was synthesized by a ThDP:ATP phosphotransferase, more recent studies indicate that it can be synthesized by two different enzymes: (1) adenylate kinase 1 in the cytosol and (2) F_oF_1-ATP synthase in brain mitochondria. Both mechanisms are conserved from bacteria to mammals. Thus ThTP synthesis does not seem to require a specific enzyme. In contrast, its hydrolysis is catalyzed, at least in mammalian tissues, by a very specific cytosolic Thiamine triphosphatase (ThTPase), controlling the steady-state cellular concentration of ThTP. In some tissues where adenylate kinase activity is high and ThTPase is absent, ThTP accumulates, reaching ≥ 70 % of total Thiamine, with no obvious physiological consequences. In some animal tissues, ThTP was able to phosphorylate proteins, and activate a high-conductance anion channel in vitro. These observations raise the possibility that ThTP is part of a still uncharacterized cellular signaling pathway. On the other hand, its synthesis by a chemiosmotic mechanism in mitochondria and respiring bacteria might suggest a role in cellular energetics.
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An alternative role of FoF1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
Scientific reports, 2013Co-Authors: Tiziana Gigliobianco, Pierre Wins, Marjorie Gangolf, Bernard Lakaye, Bastien Pirson, Christoph Von Ballmoos, Lucien BettendorffAbstract:In E. coli, Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and Pi, the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for FoF1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, FoF1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
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An alternative role of F_oF_1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
Scientific Reports, 2013Co-Authors: Tiziana Gigliobianco, Pierre Wins, Marjorie Gangolf, Bernard Lakaye, Bastien Pirson, Christoph Von Ballmoos, Lucien BettendorffAbstract:In E. coli , Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and P_i, the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F_1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for F_oF_1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, F_oF_1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
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Biochemistry of Thiamine and Thiamine Phosphate Compounds
Encyclopedia of Biological Chemistry, 2013Co-Authors: Lucien Bettendorff, Pierre WinsAbstract:Thiamine (vitamin B1) is an essential molecule for all living organisms. It is the precursor for several phosphorylated derivatives, the most important being the coenzyme Thiamine diphosphate (ThDP). Plants and microorganisms synthesize Thiamine, but humans and other animals must rely on exogenous dietary sources. Thiamine is transported into cells by specific transporters and pyrophosphorylated to ThDP in the cytosol. ThDP is a cofactor for important catabolic reactions, that is, pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase (a limiting step in the Krebs cycle), branched-chain 2-oxo acid dehydrogenase, and transketolase (a key enzyme in the pentose phosphate pathway). Therefore, ThDP is indispensable for oxidative energy metabolism. Humans are particularly sensitive to Thiamine deficiency, which mainly affects the nervous system and causes two classical diseases, beriberi (a polyneuritic syndrome) and Wernicke–Korsakoff syndrome (encephalopathy and dementia linked to alcoholism). The selective vulnerability of some brain regions is difficult to explain by general metabolic impairment; hence, a non-cofactor role of some Thiamine derivative(s) has been suggested. ThDP is the precursor for two triphosphorylated derivatives, Thiamine Triphosphate and adenosine Thiamine Triphosphate. In bacteria, those compounds are produced in response to specific conditions of nutritional downshift. Their possible role(s) in eukaryotic organisms are unknown.
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Biological functions of Thiamine derivatives: focus on non-coenzyme roles
OA Biochemistry, 2013Co-Authors: Lucien Bettendorff, Pierre WinsAbstract:Introduction Thiamine (vitamin B1) is mainly known for its diphosphorylated derivatives, an essential coenzyme in energy metabolism. However, noncoenzyme roles have been suggested for this vitamin for many years. Such roles have remained hypothetical, but recent data from various sources have shed a new light on this hypothesis. First, other phosphorylated Thiamine derivatives, most prominently Thiamine Triphosphate and adenosine Thiamine Triphosphate, can reach significant levels in Escherichia coli, respectively, during amino acid starvation and energy stress. Although much less is known about these compounds in animals, mammalian cells contain a highly specific soluble Thiamine triphosphatase controlling cytosolic Thiamine Triphosphate concentrations. Second, there is now growing evidence in favour of the existence of Thiamine-binding proteins with specific roles in the nervous system, possibly in the regulation of neurotransmitter release. Thiamine and some of its synthetic precursors with higher bioavailability have beneficial effects in several models of Alzheimer’s disease and may be beneficial for patients suffering from Alzheimer’s or Parkinson’s diseases. These effects might be related to non-coenzyme roles of Thiamine, possibly involving Thiamine-binding proteins. The aim of this review was to discuss biological
Pierre Wins - One of the best experts on this subject based on the ideXlab platform.
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Thiamine Triphosphate: a ubiquitous molecule in search of a physiological role
Metabolic Brain Disease, 2014Co-Authors: Lucien Bettendorff, Bernard Lakaye, Gregory Kohn, Pierre WinsAbstract:Thiamine Triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a more general role but this remains undefined. In contrast to Thiamine diphosphate (ThDP), ThTP is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. Though it was long thought that ThTP was synthesized by a ThDP:ATP phosphotransferase, more recent studies indicate that it can be synthesized by two different enzymes: (1) adenylate kinase 1 in the cytosol and (2) F_oF_1-ATP synthase in brain mitochondria. Both mechanisms are conserved from bacteria to mammals. Thus ThTP synthesis does not seem to require a specific enzyme. In contrast, its hydrolysis is catalyzed, at least in mammalian tissues, by a very specific cytosolic Thiamine triphosphatase (ThTPase), controlling the steady-state cellular concentration of ThTP. In some tissues where adenylate kinase activity is high and ThTPase is absent, ThTP accumulates, reaching ≥ 70 % of total Thiamine, with no obvious physiological consequences. In some animal tissues, ThTP was able to phosphorylate proteins, and activate a high-conductance anion channel in vitro. These observations raise the possibility that ThTP is part of a still uncharacterized cellular signaling pathway. On the other hand, its synthesis by a chemiosmotic mechanism in mitochondria and respiring bacteria might suggest a role in cellular energetics.
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An alternative role of F_oF_1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
Scientific Reports, 2013Co-Authors: Tiziana Gigliobianco, Pierre Wins, Marjorie Gangolf, Bernard Lakaye, Bastien Pirson, Christoph Von Ballmoos, Lucien BettendorffAbstract:In E. coli , Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and P_i, the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F_1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for F_oF_1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, F_oF_1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
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An alternative role of FoF1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
Scientific reports, 2013Co-Authors: Tiziana Gigliobianco, Pierre Wins, Marjorie Gangolf, Bernard Lakaye, Bastien Pirson, Christoph Von Ballmoos, Lucien BettendorffAbstract:In E. coli, Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and Pi, the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for FoF1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, FoF1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
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Biochemistry of Thiamine and Thiamine Phosphate Compounds
Encyclopedia of Biological Chemistry, 2013Co-Authors: Lucien Bettendorff, Pierre WinsAbstract:Thiamine (vitamin B1) is an essential molecule for all living organisms. It is the precursor for several phosphorylated derivatives, the most important being the coenzyme Thiamine diphosphate (ThDP). Plants and microorganisms synthesize Thiamine, but humans and other animals must rely on exogenous dietary sources. Thiamine is transported into cells by specific transporters and pyrophosphorylated to ThDP in the cytosol. ThDP is a cofactor for important catabolic reactions, that is, pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase (a limiting step in the Krebs cycle), branched-chain 2-oxo acid dehydrogenase, and transketolase (a key enzyme in the pentose phosphate pathway). Therefore, ThDP is indispensable for oxidative energy metabolism. Humans are particularly sensitive to Thiamine deficiency, which mainly affects the nervous system and causes two classical diseases, beriberi (a polyneuritic syndrome) and Wernicke–Korsakoff syndrome (encephalopathy and dementia linked to alcoholism). The selective vulnerability of some brain regions is difficult to explain by general metabolic impairment; hence, a non-cofactor role of some Thiamine derivative(s) has been suggested. ThDP is the precursor for two triphosphorylated derivatives, Thiamine Triphosphate and adenosine Thiamine Triphosphate. In bacteria, those compounds are produced in response to specific conditions of nutritional downshift. Their possible role(s) in eukaryotic organisms are unknown.
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Biological functions of Thiamine derivatives: focus on non-coenzyme roles
OA Biochemistry, 2013Co-Authors: Lucien Bettendorff, Pierre WinsAbstract:Introduction Thiamine (vitamin B1) is mainly known for its diphosphorylated derivatives, an essential coenzyme in energy metabolism. However, noncoenzyme roles have been suggested for this vitamin for many years. Such roles have remained hypothetical, but recent data from various sources have shed a new light on this hypothesis. First, other phosphorylated Thiamine derivatives, most prominently Thiamine Triphosphate and adenosine Thiamine Triphosphate, can reach significant levels in Escherichia coli, respectively, during amino acid starvation and energy stress. Although much less is known about these compounds in animals, mammalian cells contain a highly specific soluble Thiamine triphosphatase controlling cytosolic Thiamine Triphosphate concentrations. Second, there is now growing evidence in favour of the existence of Thiamine-binding proteins with specific roles in the nervous system, possibly in the regulation of neurotransmitter release. Thiamine and some of its synthetic precursors with higher bioavailability have beneficial effects in several models of Alzheimer’s disease and may be beneficial for patients suffering from Alzheimer’s or Parkinson’s diseases. These effects might be related to non-coenzyme roles of Thiamine, possibly involving Thiamine-binding proteins. The aim of this review was to discuss biological
Bernard Lakaye - One of the best experts on this subject based on the ideXlab platform.
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Thiamine Triphosphate: a ubiquitous molecule in search of a physiological role
Metabolic Brain Disease, 2014Co-Authors: Lucien Bettendorff, Bernard Lakaye, Gregory Kohn, Pierre WinsAbstract:Thiamine Triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a more general role but this remains undefined. In contrast to Thiamine diphosphate (ThDP), ThTP is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. Though it was long thought that ThTP was synthesized by a ThDP:ATP phosphotransferase, more recent studies indicate that it can be synthesized by two different enzymes: (1) adenylate kinase 1 in the cytosol and (2) F_oF_1-ATP synthase in brain mitochondria. Both mechanisms are conserved from bacteria to mammals. Thus ThTP synthesis does not seem to require a specific enzyme. In contrast, its hydrolysis is catalyzed, at least in mammalian tissues, by a very specific cytosolic Thiamine triphosphatase (ThTPase), controlling the steady-state cellular concentration of ThTP. In some tissues where adenylate kinase activity is high and ThTPase is absent, ThTP accumulates, reaching ≥ 70 % of total Thiamine, with no obvious physiological consequences. In some animal tissues, ThTP was able to phosphorylate proteins, and activate a high-conductance anion channel in vitro. These observations raise the possibility that ThTP is part of a still uncharacterized cellular signaling pathway. On the other hand, its synthesis by a chemiosmotic mechanism in mitochondria and respiring bacteria might suggest a role in cellular energetics.
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An alternative role of F_oF_1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
Scientific Reports, 2013Co-Authors: Tiziana Gigliobianco, Pierre Wins, Marjorie Gangolf, Bernard Lakaye, Bastien Pirson, Christoph Von Ballmoos, Lucien BettendorffAbstract:In E. coli , Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and P_i, the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F_1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for F_oF_1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, F_oF_1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
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An alternative role of FoF1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
Scientific reports, 2013Co-Authors: Tiziana Gigliobianco, Pierre Wins, Marjorie Gangolf, Bernard Lakaye, Bastien Pirson, Christoph Von Ballmoos, Lucien BettendorffAbstract:In E. coli, Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and Pi, the reaction being energized by the proton-motive force (Δp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for FoF1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, FoF1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria.
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Adenosine Thiamine Triphosphate accumulates in Escherichia coli cells in response to specific conditions of metabolic stress
BMC Microbiology, 2010Co-Authors: Tiziana Gigliobianco, Pierre Wins, Bernard Lakaye, Benaïssa El Moualij, Willy Zorzi, Lucien BettendorffAbstract:Background E. coli cells are rich in Thiamine, most of it in the form of the cofactor Thiamine diphosphate (ThDP). Free ThDP is the precursor for two triphosphorylated derivatives, Thiamine Triphosphate (ThTP) and the newly discovered adenosine Thiamine Triphosphate (AThTP). While, ThTP accumulation requires oxidation of a carbon source, AThTP slowly accumulates in response to carbon starvation, reaching ~15% of total Thiamine. Here, we address the question whether AThTP accumulation in E. coli is triggered by the absence of a carbon source in the medium, the resulting drop in energy charge or other forms of metabolic stress. Results In minimal M9 medium, E. coli cells produce AThTP not only when energy substrates are lacking but also when their metabolization is inhibited. Thus AThTP accumulates in the presence of glucose, when glycolysis is blocked by iodoacetate, or in the presence lactate, when respiration is blocked by cyanide or anoxia. In both cases, ATP synthesis is impaired, but AThTP accumulation does not appear to be a direct consequence of reduced ATP levels. Indeed, in the CV2 E. coli strain (containing a thermolabile adenylate kinase), the ATP content is very low at 37°C, even in the presence of metabolizable substrates (glucose or lactate) and under these conditions, the cells produce ThTP but not AThTP. Furthermore, we show that ThTP inhibits AThTP accumulation. Therefore, we conclude that a low energy charge is not sufficient to trigger AThTP accumulation and the latter can only accumulate under conditions where no ThTP is synthesized. We further show that AThTP production can also be induced by the uncoupler CCCP but, unexpectedly, this requires the presence of pyruvate or a substrate yielding pyruvate (such a D-glucose or L-lactate). Under the conditions described, AThTP production is not different when RelA or SpoT mutants are used. Conclusions In E. coli , AThTP accumulates in response to two different conditions of metabolic stress: lack of energy substrates (or inhibition of their metabolization) and uncoupled pyruvate oxidation. Both conditions prevent bacterial growth. There is no obvious link with the stringent response or catabolite repression.
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Adenosine Thiamine Triphosphate accumulates in Escherichia coli cells in response to specific conditions of metabolic stress
BMC microbiology, 2010Co-Authors: Tiziana Gigliobianco, Pierre Wins, Bernard Lakaye, Benaïssa El Moualij, Willy Zorzi, Lucien BettendorffAbstract:E. coli cells are rich in Thiamine, most of it in the form of the cofactor Thiamine diphosphate (ThDP). Free ThDP is the precursor for two triphosphorylated derivatives, Thiamine Triphosphate (ThTP) and the newly discovered adenosine Thiamine Triphosphate (AThTP). While, ThTP accumulation requires oxidation of a carbon source, AThTP slowly accumulates in response to carbon starvation, reaching ~15% of total Thiamine. Here, we address the question whether AThTP accumulation in E. coli is triggered by the absence of a carbon source in the medium, the resulting drop in energy charge or other forms of metabolic stress. In minimal M9 medium, E. coli cells produce AThTP not only when energy substrates are lacking but also when their metabolization is inhibited. Thus AThTP accumulates in the presence of glucose, when glycolysis is blocked by iodoacetate, or in the presence lactate, when respiration is blocked by cyanide or anoxia. In both cases, ATP synthesis is impaired, but AThTP accumulation does not appear to be a direct consequence of reduced ATP levels. Indeed, in the CV2 E. coli strain (containing a thermolabile adenylate kinase), the ATP content is very low at 37°C, even in the presence of metabolizable substrates (glucose or lactate) and under these conditions, the cells produce ThTP but not AThTP. Furthermore, we show that ThTP inhibits AThTP accumulation. Therefore, we conclude that a low energy charge is not sufficient to trigger AThTP accumulation and the latter can only accumulate under conditions where no ThTP is synthesized. We further show that AThTP production can also be induced by the uncoupler CCCP but, unexpectedly, this requires the presence of pyruvate or a substrate yielding pyruvate (such a D-glucose or L-lactate). Under the conditions described, AThTP production is not different when RelA or SpoT mutants are used. In E. coli, AThTP accumulates in response to two different conditions of metabolic stress: lack of energy substrates (or inhibition of their metabolization) and uncoupled pyruvate oxidation. Both conditions prevent bacterial growth. There is no obvious link with the stringent response or catabolite repression.
Alexander F. Makarchikov - One of the best experts on this subject based on the ideXlab platform.
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Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate-5
2011Co-Authors: Alexander F. Makarchikov, Alain Brans, Lucien BettendorffAbstract:Copyright information:Taken from "Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate"http://www.biomedcentral.com/1471-2091/8/17BMC Biochemistry 2007;8():17-17.Published online 16 Aug 2007PMCID:PMC1976097.
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Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate-0
2011Co-Authors: Alexander F. Makarchikov, Alain Brans, Lucien BettendorffAbstract:Copyright information:Taken from "Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate"http://www.biomedcentral.com/1471-2091/8/17BMC Biochemistry 2007;8():17-17.Published online 16 Aug 2007PMCID:PMC1976097. mM ADP. The flow rate was 0.5 ml/min
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Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate-6
2011Co-Authors: Alexander F. Makarchikov, Alain Brans, Lucien BettendorffAbstract:Copyright information:Taken from "Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate"http://www.biomedcentral.com/1471-2091/8/17BMC Biochemistry 2007;8():17-17.Published online 16 Aug 2007PMCID:PMC1976097. mM ADP. The flow rate was 0.5 ml/min
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Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate-2
2011Co-Authors: Alexander F. Makarchikov, Alain Brans, Lucien BettendorffAbstract:Copyright information:Taken from "Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate"http://www.biomedcentral.com/1471-2091/8/17BMC Biochemistry 2007;8():17-17.Published online 16 Aug 2007PMCID:PMC1976097.s-maleate, pH 7.0; 50 mM Tris-HCl, pH 7.5; (■) 50 mM Bis-Tris-propane; (□) 100 mM Bis-Tris-propane
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Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate-4
2011Co-Authors: Alexander F. Makarchikov, Alain Brans, Lucien BettendorffAbstract:Copyright information:Taken from "Thiamine diphosphate adenylyl transferase from : functional characterization of the enzyme synthesizing adenosine Thiamine Triphosphate"http://www.biomedcentral.com/1471-2091/8/17BMC Biochemistry 2007;8():17-17.Published online 16 Aug 2007PMCID:PMC1976097.rve with an of 0.08 mM. The inset shows a Hill plot obtained for ADP concentrations ranging from 0.04 to 0.6 mM. The Hill coefficient (n= 2.1) was calculated from the slope of the regression line over the linear portion of the graph (0.01 – 0.20 mM ADP)
Bettendorff Lucien - One of the best experts on this subject based on the ideXlab platform.
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In search of a physiological role for Thiamine Triphosphate and the 25-kDa Thiamine triphosphatase
2014Co-Authors: Bettendorff Lucien, Lakaye Bernard, Kohn Grégory, Wins PierreAbstract:audience: researcher, professionalIn search of a physiological role for Thiamine Triphosphate and the 25-kDa Thiamine triphosphatase L. BETTENDORFF, B. LAKAYE, G. KOHN AND P. WINS GIGA-Neurosciences, University of Liège, 4000-Liège, Belgium Thiamine Triphosphate (ThTP) was discovered over 60 years ago. Although it is present in most organisms from bacteria to mammals, its possible biological functions remain unclear. In contrast to Thiamine diphosphate (ThDP), it is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. In some animal tissues, ThTP was able to phosphorylate proteins and activate a high-conductance anion channel in vitro. These observations raised the possibility of ThTP being part of a still uncharacterized cellular signaling pathway. Though it was long thought that ThTP is synthesized by a specific ThDP:ATP phosphotransferase, more recent studies indicate that two main mechanisms are involved: (1) in the cytosol adenylate kinase 1 can catalyze ThTP production from ThDP and ADP and (2) in brain mitochondria FoF1-ATP synthase can catalyze ThTP production from ThDP + Pi. The latter reaction is energized by the respiratory chain through a chemiosmotic mechanism analogous to oxidative phosphorylation. Both mechanisms are conserved from bacteria to mammals. While ThTP synthesis does not seem to require a specific enzyme, its hydrolysis in mammalian tissues is catalyzed by a very specific cytosolic 25 kDa Thiamine triphosphatase (ThTPase). Because of this activity, steady-state ThTP levels are kept low in mammalian cells. ThTPase belongs to the CYTH superfamily of proteins which has representatives in all superkingdoms of life acting on tripolyphosphate and various triphosphorylated substrates. Although the whole chromosome region containing the ThTPase gene was lost in birds, orthologs of the ThTPase gene were found in all other known metazoan genomes. It seems that ThTPase activity appeared as a secondary acquisition of the CYTH proteins in the lineage leading from cnidarians to vertebrates. In particular, the Trp-53 residue of mammalian ThTPases plays a key role in substrate recognition and specificity by interacting with the thiazole part of ThTP. This residue is conserved in metazoan CYTH proteins with ThTPase activity. In order to gain insight into the physiological function(s) of the ThTP-ThTPase couple, we tried to produce a mouse invalidated in 25-kDa ThTPase. Surprisingly, we were unable to obtain any knockout animal, apparently because ThTPase seems to be required for spermatogenesis. As we previously showed that the enzyme is much more abundant in differentiated versus undifferentiated cells, we suspect that 25-kDa ThTPase might play a more general and important role during cell differentiation. Acknowledgments This work was supported by the F.R.S.-FNRS. LB and BL are respectively Research Director and Research Associate at the F.R.S.-FNRS
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Thiamine Triphosphate: a ubiquitous molecule in search of a physiological role
2014Co-Authors: Bettendorff Lucien, Wins PierreAbstract:Thiamine Triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a more general role but this remains undefined. In contrast to Thiamine diphosphate (ThDP), ThTP is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. Though it was long thought that ThTP was synthesized by a ThDP:ATP phosphotransferase, more recent studies indicate that it can be synthesized by two different enzymes: (1) adenylate kinase 1 in the cytosol and (2) FoF1-ATP synthase in brain mitochondria. Both mechanisms are conserved from bacteria to mammals. Thus ThTP synthesis does not seem to require a specific enzyme. In contrast, its hydrolysis is catalyzed, at least in mammalian tissues, by a very specific cytosolic Thiamine triphosphatase (ThTPase), controlling the steady-state cellular concentration of ThTP. In some tissues where adenylate kinase activity is high and ThTPase is absent, ThTP accumulates, reaching ≥ 70% of total Thiamine, with no obvious physiological consequences. In some animal tissues, ThTP was able to phosphorylate proteins, and activate a high-conductance anion channel in vitro. These observations raise the possibility that ThTP is part of a still uncharacterized cellular signaling pathway. On the other hand, its synthesis by a chemiosmotic mechanism in mitochondria and respiring bacteria might suggest a role in cellular energetics.Peer reviewe
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In search of a physiological role for Thiamine Triphosphate and the 25-kDa Thiamine triphosphatase
2014Co-Authors: Bettendorff Lucien, Lakaye Bernard, Kohn Grégory, Wins PierreAbstract:In search of a physiological role for Thiamine Triphosphate and the 25-kDa Thiamine triphosphatase L. BETTENDORFF, B. LAKAYE, G. KOHN AND P. WINS GIGA-Neurosciences, University of Liège, 4000-Liège, Belgium Thiamine Triphosphate (ThTP) was discovered over 60 years ago. Although it is present in most organisms from bacteria to mammals, its possible biological functions remain unclear. In contrast to Thiamine diphosphate (ThDP), it is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. In some animal tissues, ThTP was able to phosphorylate proteins and activate a high-conductance anion channel in vitro. These observations raised the possibility of ThTP being part of a still uncharacterized cellular signaling pathway. Though it was long thought that ThTP is synthesized by a specific ThDP:ATP phosphotransferase, more recent studies indicate that two main mechanisms are involved: (1) in the cytosol adenylate kinase 1 can catalyze ThTP production from ThDP and ADP and (2) in brain mitochondria FoF1-ATP synthase can catalyze ThTP production from ThDP + Pi. The latter reaction is energized by the respiratory chain through a chemiosmotic mechanism analogous to oxidative phosphorylation. Both mechanisms are conserved from bacteria to mammals. While ThTP synthesis does not seem to require a specific enzyme, its hydrolysis in mammalian tissues is catalyzed by a very specific cytosolic 25 kDa Thiamine triphosphatase (ThTPase). Because of this activity, steady-state ThTP levels are kept low in mammalian cells. ThTPase belongs to the CYTH superfamily of proteins which has representatives in all superkingdoms of life acting on tripolyphosphate and various triphosphorylated substrates. Although the whole chromosome region containing the ThTPase gene was lost in birds, orthologs of the ThTPase gene were found in all other known metazoan genomes. It seems that ThTPase activity appeared as a secondary acquisition of the CYTH proteins in the lineage leading from cnidarians to vertebrates. In particular, the Trp-53 residue of mammalian ThTPases plays a key role in substrate recognition and specificity by interacting with the thiazole part of ThTP. This residue is conserved in metazoan CYTH proteins with ThTPase activity. In order to gain insight into the physiological function(s) of the ThTP-ThTPase couple, we tried to produce a mouse invalidated in 25-kDa ThTPase. Surprisingly, we were unable to obtain any knockout animal, apparently because ThTPase seems to be required for spermatogenesis. As we previously showed that the enzyme is much more abundant in differentiated versus undifferentiated cells, we suspect that 25-kDa ThTPase might play a more general and important role during cell differentiation. Acknowledgments This work was supported by the F.R.S.-FNRS. LB and BL are respectively Research Director and Research Associate at the F.R.S.-FNRS
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Thiamine Triphosphate: a ubiquitous molecule in search of a physiological role
'Springer Science and Business Media LLC', 2014Co-Authors: Bettendorff Lucien, Wins PierreAbstract:peer reviewedaudience: researcher, professional, studentThiamine Triphosphate (ThTP) was discovered over 60 years ago and it was long thought to be a specifically neuroactive compound. Its presence in most cell types, from bacteria to mammals, would suggest a more general role but this remains undefined. In contrast to Thiamine diphosphate (ThDP), ThTP is not a coenzyme. In E. coli cells, ThTP is transiently produced in response to amino acid starvation, while in mammalian cells, it is constitutively produced at a low rate. Though it was long thought that ThTP was synthesized by a ThDP:ATP phosphotransferase, more recent studies indicate that it can be synthesized by two different enzymes: (1) adenylate kinase 1 in the cytosol and (2) FoF1-ATP synthase in brain mitochondria. Both mechanisms are conserved from bacteria to mammals. Thus ThTP synthesis does not seem to require a specific enzyme. In contrast, its hydrolysis is catalyzed, at least in mammalian tissues, by a very specific cytosolic Thiamine triphosphatase (ThTPase), controlling the steady-state cellular concentration of ThTP. In some tissues where adenylate kinase activity is high and ThTPase is absent, ThTP accumulates, reaching ≥ 70% of total Thiamine, with no obvious physiological consequences. In some animal tissues, ThTP was able to phosphorylate proteins, and activate a high-conductance anion channel in vitro. These observations raise the possibility that ThTP is part of a still uncharacterized cellular signaling pathway. On the other hand, its synthesis by a chemiosmotic mechanism in mitochondria and respiring bacteria might suggest a role in cellular energetics
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An alternative role of FoF1-ATP synthase in Escherichia coli: synthesis of Thiamine Triphosphate
'Springer Science and Business Media LLC', 2013Co-Authors: Gigliobianco Tiziana, Wins Pierre, Lakaye Bernard, Gangolf Marjorie, Pirson Bastien, Von Ballmoos Christoph, Bettendorff LucienAbstract:peer reviewedaudience: researcher, professional, studentIn E. coli, Thiamine Triphosphate (ThTP), a putative signaling molecule, transiently accumulates in response to amino acid starvation. This accumulation requires the presence of an energy substrate yielding pyruvate. Here we show that in intact bacteria ThTP is synthesized from free Thiamine diphosphate (ThDP) and Pi, the reaction being energized by the proton-motive force (Dp) generated by the respiratory chain. ThTP production is suppressed in strains carrying mutations in F1 or a deletion of the atp operon. Transformation with a plasmid encoding the whole atp operon fully restored ThTP production, highlighting the requirement for FoF1-ATP synthase in ThTP synthesis. Our results show that, under specific conditions of nutritional downshift, FoF1-ATP synthase catalyzes the synthesis of ThTP, rather than ATP, through a highly regulated process requiring pyruvate oxidation. Moreover, this chemiosmotic mechanism for ThTP production is conserved from E. coli to mammalian brain mitochondria