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Suganuma Y, Sumi-Ichinose C, Kano T, Ikemoto K, Matsui T, Ichinose H, Kondo K. Quinonoid dihydropteridine reductase, a tetrahydrobiopterin-recycling enzyme, contributes to 5-hydroxytryptamine-associated platelet aggregation in mice. J Pharmacol Sci 2022; 150:173-179. [DOI: 10.1016/j.jphs.2022.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/09/2022] [Accepted: 08/25/2022] [Indexed: 10/31/2022] Open
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2
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Shen P, Gu S, Jin D, Su Y, Wu H, Li Q, Yang J, He W, Huang J, Qi F. Engineering Metabolic Pathways for Cofactor Self-Sufficiency and Serotonin Production in Escherichia coli. ACS Synth Biol 2022; 11:2889-2900. [PMID: 35866382 DOI: 10.1021/acssynbio.2c00298] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Serotonin is a neurotransmitter that plays an essential regulatory role in numerous cognitive and behavioral functions. Recent advances in synthetic biology have enabled engineering of non-natural biosynthetic pathways for serotonin production in E. coli. Here, an optimized heterologous serotonin biosynthetic pathway was engineered in E. coli and coupled with the biosynthetic and regeneration modules of the endogenous vital cofactor tetrahydrobiopterin (BH4) for efficient serotonin production using whole-cell catalysis. Further metabolic engineering efforts were performed to ensure an adequate endogenous BH4 supply, including enhancements of GTP biosynthesis and intracellular reducing power availability. Using the optimized fed-batch fermentation, an overall maximum serotonin yield of 40.3% (mol/mol) and a peak titer of 1.68 g/L (production rate of 0.016 g/L/h) were achieved. The strategies employed in this study show the promise of using E. coli for pterin self-sufficiency and high-level serotonin production, and the engineered strains hold the potential for use in industrial applications.
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Affiliation(s)
- Peijie Shen
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Suyi Gu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Dou Jin
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Yu Su
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Hongxuan Wu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Qingchen Li
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Jinhua Yang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Wenjin He
- Center of Engineering Technology Research for Microalgae Germplasm Improvement of Fujian, Southern Institute of Oceanography, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Jianzhong Huang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Feng Qi
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, Fujian, China.,Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation & Provincial University Engineering Research Center of Industrial Biocatalysis, Fujian Normal University, Fuzhou 350117, Fujian, China
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3
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Gonçalves S, Nunes-Costa D, Cardoso SM, Empadinhas N, Marugg JD. Enzyme Promiscuity in Serotonin Biosynthesis, From Bacteria to Plants and Humans. Front Microbiol 2022; 13:873555. [PMID: 35495641 PMCID: PMC9048412 DOI: 10.3389/fmicb.2022.873555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/29/2022] [Indexed: 12/12/2022] Open
Abstract
Serotonin is a phylogenetically ancient compound found in animals, plants, and some bacteria. In eukaryotes, serotonin is synthesized from the aromatic amino acid tryptophan via the key enzymes aromatic amino acid hydroxylase (AAAH) and aromatic amino acid decarboxylase (AAAD). Serotonin is also an intermediate in the melatonin biosynthetic pathway and is involved in several vital functions. In humans, serotonin is produced in the gut and in the brain, is critical in the regulation of multiple body functions, and its depletion has been implicated in multiple neurological disorders including depression and Alzheimer’s disease, as well as other peripheral conditions namely irritable bowel syndrome and fibromyalgia. The serotonin biosynthetic pathway is well described in eukaryotes, but very little is known about this pathway in bacteria. Evidence points to similar pathways since eukaryote-like AAAH and AAAD (and their genes) have been identified in multiple bacteria, even though serotonin production has not yet been detected in most species. Although data on bacterial tryptophan decarboxylase genes are very limited and no bacterial tryptophan hydroxylase genes have been identified to date, evidence suggests that serotonin production in bacteria might occur through different AAAH and AAAD. Substrate promiscuity in these enzymes has been previously reported and seems to be the key aspect in bacterial serotonin synthesis. Considering the human gut microbiota as a potential source of serotonin, further investigation on its biosynthetic pathways in microbes might lead to important discoveries, which may ultimately foster the development of new therapeutic strategies to treat serotonin depletion-related disorders in humans.
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Affiliation(s)
- Sara Gonçalves
- CNC-Center for Neuroscience and Cell Biology, CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
| | - Daniela Nunes-Costa
- CNC-Center for Neuroscience and Cell Biology, CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,PhD Program in Experimental Biology and Biomedicine (PDBEB), Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Sandra Morais Cardoso
- CNC-Center for Neuroscience and Cell Biology, CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,Institute of Cell and Molecular Biology, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Nuno Empadinhas
- CNC-Center for Neuroscience and Cell Biology, CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal.,IIIUC-Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - John David Marugg
- CNC-Center for Neuroscience and Cell Biology, CIBB-Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
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4
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Han Y, Peng L, Wang T. Tadr Is an axonal histidine transporter required for visual neurotransmission in Drosophila. eLife 2022; 11:75821. [PMID: 35229720 PMCID: PMC8916773 DOI: 10.7554/elife.75821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/28/2022] [Indexed: 11/13/2022] Open
Abstract
Neurotransmitters are generated by de novo synthesis and are essential for sustained, high-frequency synaptic transmission. Histamine, a monoamine neurotransmitter, is synthesized through decarboxylation of histidine by Histidine decarboxylase (Hdc). However, little is known about how histidine is presented to Hdc as a precursor. Here, we identified a specific histidine transporter, TADR (Torn And Diminished Rhabdomeres), which is required for visual transmission in Drosophila. Both TADR and Hdc localized to neuronal terminals, and mutations in tadr reduced levels of histamine, thus disrupting visual synaptic transmission and phototaxis behavior. These results demonstrate that a specific amino acid transporter provides precursors for monoamine neurotransmitters, providing the first genetic evidence that a histidine amino acid transporter plays a critical role in synaptic transmission. These results suggest that TADR-dependent local de novo synthesis of histamine is required for synaptic transmission.
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Affiliation(s)
- Yongchao Han
- National Institute of Biological Sciences, Beijing, Beijing, China
| | - Lei Peng
- National Institute of Biological Sciences, Beijing, Beijing, China
| | - Tao Wang
- National Institute of Biological Sciences, Beijing, Beijing, China
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5
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Xie X, Ding D, Bai D, Zhu Y, Sun W, Sun Y, Zhang D. Melatonin biosynthesis pathways in nature and its production in engineered microorganisms. Synth Syst Biotechnol 2022; 7:544-553. [PMID: 35087957 PMCID: PMC8761603 DOI: 10.1016/j.synbio.2021.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/14/2021] [Accepted: 12/24/2021] [Indexed: 12/26/2022] Open
Abstract
Melatonin is a biogenic amine that can be found in plants, animals and microorganism. The metabolic pathway of melatonin is different in various organisms, and biosynthetic endogenous melatonin acts as a molecular signal and antioxidant protection against external stress. Microbial synthesis pathways of melatonin are similar to those of animals but different from those of plants. At present, the method of using microorganism fermentation to produce melatonin is gradually prevailing, and exploring the biosynthetic pathway of melatonin to modify microorganism is becoming the mainstream, which has more advantages than traditional chemical synthesis. Here, we review recent advances in the synthesis, optimization of melatonin pathway. l-tryptophan is one of the two crucial precursors for the synthesis of melatonin, which can be produced through a four-step reaction. Enzymes involved in melatonin synthesis have low specificity and catalytic efficiency. Site-directed mutation, directed evolution or promotion of cofactor synthesis can enhance enzyme activity and increase the metabolic flow to promote microbial melatonin production. On the whole, the status and bottleneck of melatonin biosynthesis can be improved to a higher level, providing an effective reference for future microbial modification.
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Affiliation(s)
- Xiaotong Xie
- Dalian Polytechnic University, Dalian, 116000, PR China
| | - Dongqin Ding
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Danyang Bai
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Yaru Zhu
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Wei Sun
- Tianjin University of science and technology, Tianjin, 300308, PR China
| | - Yumei Sun
- Dalian Polytechnic University, Dalian, 116000, PR China
- Corresponding author.
| | - Dawei Zhang
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Corresponding author. Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China.
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6
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Jiao J, Xia Y, Zhang Y, Wu X, Liu C, Feng J, Zheng X, Song S, Bai T, Song C, Wang M, Pang H. Phenylalanine 4-Hydroxylase Contributes to Endophytic Bacterium Pseudomonas fluorescens' Melatonin Biosynthesis. Front Genet 2021; 12:746392. [PMID: 34868217 PMCID: PMC8634680 DOI: 10.3389/fgene.2021.746392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/13/2021] [Indexed: 11/18/2022] Open
Abstract
Melatonin acts both as an antioxidant and as a growth regulatory substance in plants. Pseudomonas fluorescens endophytic bacterium has been shown to produce melatonin and increase plant resistance to abiotic stressors through increasing endogenous melatonin. However, in bacteria, genes are still not known to be melatonin-related. Here, we reported that the bacterial phenylalanine 4-hydroxylase (PAH) may be involved in the 5-hydroxytryptophan (5-HTP) biosynthesis and further influenced the subsequent production of melatonin in P. fluorescens. The purified PAH protein of P. fluorescens not only hydroxylated phenylalanine but also exhibited l-tryptophan (l-Trp) hydroxylase activity by converting l-Trp to 5-HTP in vitro. However, bacterial PAH displayed lower activity and affinity for l-Trp than l-phenylalanine. Notably, the PAH deletion of P. fluorescens blocked melatonin production by causing a significant decline in 5-HTP levels and thus decreased the resistance to abiotic stress. Overall, this study revealed a possible role for bacterial PAH in controlling 5-HTP and melatonin biosynthesis in bacteria, and expanded the current knowledge of melatonin production in microorganisms.
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Affiliation(s)
- Jian Jiao
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Yan Xia
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Yingli Zhang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Xueli Wu
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Chonghuai Liu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Jiancan Feng
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Xianbo Zheng
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Shangwei Song
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Tuanhui Bai
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Chunhui Song
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Miaomiao Wang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Hongguang Pang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
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7
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Cheng J, Li W, Wang Y, Cao Q, Ni Y, Zhang W, Guo J, Chen B, Zang Y, Zhu Y. Electroacupuncture modulates the intestinal microecology to improve intestinal motility in spinal cord injury rats. Microb Biotechnol 2021; 15:862-873. [PMID: 34797954 PMCID: PMC8913878 DOI: 10.1111/1751-7915.13968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 12/14/2022] Open
Abstract
Spinal cord injury (SCI) is a disease involving gastrointestinal disorders. The underlying mechanisms of the potential protective effects of electroacupuncture (EA) and 5-hydroxytryptamine (5-HT) system on SCI remain unknown. We investigated whether EA improves gut microbial dysbiosis in SCI and regulates the 5-HT system. 16S rDNA gene sequencing was applied to investigate alterations in the gut microbiome of the rats. Faecal metabolites and the expression of the 5-HT system were detected. EA and faecal microbiota transplantation (FMT) treatment facilitated intestinal transmission functional recovery and restored the colon morphology of SCI rats. The composition of the intestinal microbiota, including numbers of phylum Proteobacteria, class Clostridia, order Bacteroidales, and genus Dorea, were amplified in SCI rats, and EA and FMT significantly reshaped the intestinal microbiota. SCI resulted in disturbed metabolic conditions in rats, and the EA and FMT group showed increased amounts of catechin compared with SCI rats. SCI inhibited 5-HT system expression in the colon, which was significantly reversed by EA and FMT treatment. Therefore, EA may ameliorate SCI by modulating microbiota and metabolites and regulate the 5-HT system. Our study provides new insights into the pathogenesis and therapy of SCI from the perspective of microbiota and 5-HT regulation.
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Affiliation(s)
- Jie Cheng
- Nanjing University of Chinese Medicine, Nanjing, China
| | - Weimin Li
- The Second Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Ying Wang
- The Ninth People's Hospital of Wuxi affiliated to Soochow University, Wuxi, China.,Department of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Qing Cao
- Department of Kinesiology, Shanghai University of Sport, Shanghai, China.,Zigong Forth People's Hospital, Zigong, China
| | - Ying Ni
- Nanjing University of Chinese Medicine, Nanjing, China
| | - Wenyi Zhang
- Zhongshan Rehabilitation Hospital Affiliated to Jiangsu Provincial People's Hospital, Nanjing, China
| | - Jiabao Guo
- The Second Clinical Medical School, Xuzhou Medical University, Xuzhou, China
| | - Binglin Chen
- The Second Clinical Medical School, Xuzhou Medical University, Xuzhou, China
| | - Yaning Zang
- Department of Kinesiology, Shanghai University of Sport, Shanghai, China
| | - Yi Zhu
- The Second Affiliated Hospital of Hainan Medical University, Haikou, China.,The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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8
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Mammoli A, Riccio A, Bianconi E, Coletti A, Camaioni E, Macchiarulo A. One Key and Multiple Locks: Substrate Binding in Structures of Tryptophan Dioxygenases and Hydroxylases. ChemMedChem 2021; 16:2732-2743. [PMID: 34137184 PMCID: PMC8518741 DOI: 10.1002/cmdc.202100312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 06/14/2021] [Indexed: 12/18/2022]
Abstract
Since its discovery at the beginning of the past century, the essential nutrient l-Tryptophan (l-Trp) and its catabolic pathways have acquired an increasing interest in an ever wider scientific community for their pivotal roles in underlying many important physiological functions and associated pathological conditions. As a consequence, enzymes catalyzing rate limiting steps along l-Trp catabolic pathways - including IDO1, TDO, TPH1 and TPH2 - have turned to be interesting drug targets for the design and development of novel therapeutic agents for different disorders such as carcinoid syndrome, cancer and autoimmune diseases. This article provides a fresh comparative overview on the most recent advancements that crystallographic studies, biophysical and computational works have brought on structural aspects and molecular recognition patterns of these enzymes toward l-Trp. Finally, a conformational analysis of l-Trp is also discussed as part of the molecular recognition process governing the binding of a substrate to its cognate enzymes.
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Affiliation(s)
- Andrea Mammoli
- Department of Pharmaceutical SciencesUniversity of PerugiaVia del Liceo N. 106123PerugiaItaly
| | - Alessandra Riccio
- Department of Pharmaceutical SciencesUniversity of PerugiaVia del Liceo N. 106123PerugiaItaly
| | - Elisa Bianconi
- Department of Pharmaceutical SciencesUniversity of PerugiaVia del Liceo N. 106123PerugiaItaly
| | - Alice Coletti
- Department of Medicine and SurgeryUniversity of PerugiaP. le Gambuli06132PerugiaItaly
| | - Emidio Camaioni
- Department of Pharmaceutical SciencesUniversity of PerugiaVia del Liceo N. 106123PerugiaItaly
| | - Antonio Macchiarulo
- Department of Pharmaceutical SciencesUniversity of PerugiaVia del Liceo N. 106123PerugiaItaly
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9
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Mordhorst A, Dhandapani P, Matthes S, Mosienko V, Rothe M, Todiras M, Self J, Schunck WH, Schütz A, Bader M, Alenina N. Phenylalanine hydroxylase contributes to serotonin synthesis in mice. FASEB J 2021; 35:e21648. [PMID: 33993565 DOI: 10.1096/fj.202100366r] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/11/2021] [Accepted: 04/21/2021] [Indexed: 12/31/2022]
Abstract
Serotonin is an important signaling molecule in the periphery and in the brain. The hydroxylation of tryptophan is the first and rate-limiting step of its synthesis. In most vertebrates, two enzymes have been described to catalyze this step, tryptophan hydroxylase (TPH) 1 and 2, with expression localized to peripheral and neuronal cells, respectively. However, animals lacking both TPH isoforms still exhibit about 10% of normal serotonin levels in the blood demanding an additional source of the monoamine. In this study, we provide evidence by the gain and loss of function approaches in in vitro and in vivo systems, including stable-isotope tracing in mice, that phenylalanine hydroxylase (PAH) is a third TPH in mammals. PAH contributes to serotonin levels in the blood, and may be important as a local source of serotonin in organs in which no other TPHs are expressed, such as liver and kidney.
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Affiliation(s)
- Alexander Mordhorst
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany.,Charite - University Medicine, Berlin, Germany
| | - Priyavathi Dhandapani
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Susann Matthes
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Valentina Mosienko
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | | | - Mihail Todiras
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Moldova
| | - Julie Self
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Wolf-Hagen Schunck
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Anja Schütz
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Michael Bader
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany.,Charite - University Medicine, Berlin, Germany.,Institute for Biology, University of Lübeck, Lübeck, Germany
| | - Natalia Alenina
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany.,Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia.,Institute of Cytology, Russian Academy of Science, St. Petersburg, Russia
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10
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Suga N, Murakami A, Arimitsu H, Nakamura T, Nakamura Y, Kato Y. Luteolin suppresses 5-hydroxytryptamine elevation in stimulated RBL-2H3 cells and experimental colitis mice. J Clin Biochem Nutr 2021; 69:20-27. [PMID: 34376910 PMCID: PMC8325766 DOI: 10.3164/jcbn.20-192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/20/2020] [Indexed: 01/11/2023] Open
Abstract
Increased 5-hydroxytryptamine may be associated with the development and progression of inflammatory bowel disease. In this study, we examined the suppressive effect of flavonoids on the increased intra- and extracellular 5-hydroxytryptamine levels in rat mast RBL-2H3 cells, known to produce 5-hydroxytryptamine by the phorbol 12-myristate 13-acetate stimulation. Among the flavonoids examined, luteolin and quercetin significantly reduced the cellular 5-hydroxytryptamine concentration. Gene and protein expression analyses revealed that luteolin significantly suppressed cellular tryptophan hydroxylase 1 expression induced by phorbol 12-myristate 13-acetate stimulation. Mitogen-activated protein kinase/extracellular signal-regulated kinase signaling was also suppressed by luteolin, suggesting that this pathway is one of targets of 5-hydroxytryptamine modulation by luteolin. An in vivo experimental colitis model was prepared by administering 2.5% dextran sodium sulfate in drinking water to C57BL/6 mice for seven days. The ingestion of 0.1% dietary luteolin suppressed the increasing 5-hydroxytryptamine in the colorectal mucosa. In conclusion, luteolin possesses a suppressive effect on extensive 5-hydroxytryptamine formation in both experimental RBL-2H3 cells and colitis models.
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Affiliation(s)
- Naoko Suga
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Akira Murakami
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Hideyuki Arimitsu
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Toshiyuki Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Okayama 700-8530, Japan
| | - Yoshimasa Nakamura
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Okayama 700-8530, Japan
| | - Yoji Kato
- Graduate School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan.,Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan
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11
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Wigner P, Synowiec E, Jóźwiak P, Czarny P, Bijak M, Białek K, Szemraj J, Gruca P, Papp M, Śliwiński T. The Effect of Chronic Mild Stress and Venlafaxine on the Expression and Methylation Levels of Genes Involved in the Tryptophan Catabolites Pathway in the Blood and Brain Structures of Rats. J Mol Neurosci 2020; 70:1425-1436. [PMID: 32406039 PMCID: PMC7399689 DOI: 10.1007/s12031-020-01563-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 04/22/2020] [Indexed: 12/21/2022]
Abstract
A growing body of evidence suggests that depression may be associated with impairment of the tryptophan catabolites (TRYCATs) pathway. The present study investigated the effects of the chronic administration of venlafaxine on the expression and methylation status of Katl, Tph1/2, Ido1, Kmo and Kynu in the brain and blood of rats exposed to the CMS model of depression. The rats were subjected to the CMS procedure for 2 or 7 weeks and administered venlafaxine (10 mg/kg/day, IP) for 5 weeks. mRNA and protein expression and the methylation status of gene promoters in PBMCs and six brain structures were evaluated and analysed using the TaqMan Gene Expression Assay and Western blotting, and methylation-sensitive high-resolution melting (MS-HRM), respectively. We found that the CMS procedure increased KatI expression in the midbrain and KatII expression in the midbrain and the amygdala, while venlafaxine administration decreased KatII expression in the hypothalamus and the cerebral cortex. The methylation status of the Tph1 and Kmo promoters in peripheral blood mononuclear cells (PBMCs) was significantly increased in the stressed group after antidepressant therapy. The protein levels of Tph1 and Ido1 were decreased following venlafaxine administration. Our results confirmed that CMS and venlafaxine modulate the expression levels and methylation status of genes involved in the TRYCATs pathway.
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Affiliation(s)
- Paulina Wigner
- Faculty of Biology and Environmental Protection, Laboratory of Medical Genetics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Ewelina Synowiec
- Faculty of Biology and Environmental Protection, Laboratory of Medical Genetics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Paweł Jóźwiak
- Faculty of Biology and Environmental Protection, Department of Cytobiochemistry, University of Lodz, Lodz, Poland
| | - Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Michał Bijak
- Faculty of Biology and Environmental Protection, Department of General Biochemistry, University of Lodz, Lodz, Poland
| | - Katarzyna Białek
- Faculty of Biology and Environmental Protection, Laboratory of Medical Genetics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Janusz Szemraj
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Piotr Gruca
- Polish Academy of Sciences, Institute of Pharmacology, Krakow, Poland
| | - Mariusz Papp
- Polish Academy of Sciences, Institute of Pharmacology, Krakow, Poland
| | - Tomasz Śliwiński
- Faculty of Biology and Environmental Protection, Laboratory of Medical Genetics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland.
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12
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Lv Y, Li Y, Li J, Bian C, Qin C, Shi Q. A Comparative Genomics Study on the Molecular Evolution of Serotonin/Melatonin Biosynthesizing Enzymes in Vertebrates. Front Mol Biosci 2020; 7:11. [PMID: 32118037 PMCID: PMC7010912 DOI: 10.3389/fmolb.2020.00011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/17/2020] [Indexed: 11/13/2022] Open
Abstract
Serotonin is important in vertebrates for its crucial roles in regulation of various physiological functions. Investigations on how the biosynthesizing enzymes mediate serotonin production and conversion during biological processes have been active in the past decades. However, a clear-cut picture of these enzymes in molecular evolution is very limited, particularly when the complexity is imaginable in fishes since teleosts had experienced additional whole genome duplication (WGD) event(s) than tetrapods. Since serotonin is the main intermediate product during melatonin biosynthesis from tryptophan, we therefore summarize an overview of recent discoveries about molecular evolution of the four melatonin biosynthesizing enzymes, especially the L-aromatic amino acid decarboxylase (AAAD) for serotonin production and aralkylamine N-acetyltransferase (AANAT) for serotonin conversion in vertebrates. Novel copies of these genes, possibly due to WGD, were discovered in fishes. Detailed sequence comparisons revealed various variant sites in these newly identified genes, suggesting functional changes from the conventional recognition of these enzymes. These interesting advances will benefit readers to obtain new insights into related genomic differences between mammals and fishes, with an emphasis on the potential specificity for AANAT in naturally cave-restricted and deep-sea fishes.
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Affiliation(s)
- Yunyun Lv
- Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, College of Life Sciences, Neijiang Normal University, Neijiang, China
| | - Yanping Li
- Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, College of Life Sciences, Neijiang Normal University, Neijiang, China.,Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen, China
| | - Jia Li
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen, China
| | - Chao Bian
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen, China
| | - Chuanjie Qin
- Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, College of Life Sciences, Neijiang Normal University, Neijiang, China
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen, China
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13
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Reilley DJ, Popov KI, Dokholyan NV, Alexandrova AN. Uncovered Dynamic Coupling Resolves the Ambiguous Mechanism of Phenylalanine Hydroxylase Oxygen Binding. J Phys Chem B 2019; 123:4534-4539. [PMID: 31038957 DOI: 10.1021/acs.jpcb.9b02893] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Phenylalanine hydroxylase (PAH) is an iron enzyme catalyzing the oxidation of l-Phe to l-Tyr during phenylalanine catabolism. Dysfunction of PAH leads to the debilitating condition phenylketonuria (PKU), which prompted research into the structure and function of PAH over the last 50 years. Despite intensive study, there is no consensus on the atomistic details of the mechanism of O2 binding and splitting by wild-type (WT) PAH and how it varies with PKU-inducing mutations, Arg158Gln and Glu280Lys. We studied structures involved in a proposed mechanism for the WT and mutants using extensive mixed quantum-classical molecular dynamics simulations. Simulations reveal a previously unobserved dynamic coupling between the active site and the mutation sites, suggesting how they can affect the catalytic performance of PAH. Furthermore, the effect of the coupling on the PAH structure agrees with and expands our understanding of the experimentally observed differences in activity between the WT and mutants.
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Affiliation(s)
- David J Reilley
- Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095-1569 , United States
| | - Konstantin I Popov
- Department of Biochemistry and Biophysics , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Nikolay V Dokholyan
- Department of Biochemistry and Biophysics , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States.,Department of Pharmacology, Department of Biochemistry & Molecular Biology , Penn State University College of Medicine , Hershey , Pennsylvania 17033 , United States
| | - Anastassia N Alexandrova
- Department of Chemistry and Biochemistry , University of California, Los Angeles , Los Angeles , California 90095-1569 , United States.,California NanoSystems Institute, Los Angeles , California 90095-1569 , United States
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14
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Xu J, Li Y, Lv Y, Bian C, You X, Endoh D, Teraoka H, Shi Q. Molecular Evolution of Tryptophan Hydroxylases in Vertebrates: A Comparative Genomic Survey. Genes (Basel) 2019; 10:genes10030203. [PMID: 30857219 PMCID: PMC6470480 DOI: 10.3390/genes10030203] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/19/2019] [Accepted: 03/04/2019] [Indexed: 02/02/2023] Open
Abstract
Serotonin is a neurotransmitter involved in various physiological processes in the central and peripheral nervous systems. Serotonin is also a precursor for melatonin biosynthesis, which mainly occurs in the pineal gland of vertebrates. Tryptophan hydroxylase (TPH) acts as the rate-limiting enzyme in serotonin biosynthesis and is the initial enzyme involved in the synthesis of melatonin. Recently, two enzymes—TPH1 and TPH2—were reported to form the TPH family in vertebrates and to play divergent roles in serotonergic systems. Here, we examined the evolution of the TPH family from 70 vertebrate genomes. Based on the sequence similarity, we extracted 184 predicted tph homologs in the examined vertebrates. A phylogenetic tree, constructed on the basis of these protein sequences, indicated that tph genes could be divided into two main clades (tph1 and tph2), and that the two clades were further split into two subgroups of tetrapods and Actinopterygii. In tetrapods, and some basal non-teleost ray-finned fishes, only two tph isotypes exist. Notably, tph1 in most teleosts that had undergone the teleost-specific genome duplication could be further divided into tph1a and tph1b. Moreover, protein sequence comparisons indicated that TPH protein changes among vertebrates were concentrated at the NH2-terminal. The tertiary structures of TPH1 and TPH2 revealed obvious differences in the structural elements. Five positively selected sites were characterized in TPH2 compared with TPH1; these sites may reflect the functional divergence in enzyme activity and substrate specificity. In summary, our current work provides novel insights into the evolution of tph genes in vertebrates from a comprehensive genomic perspective.
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Affiliation(s)
- Junmin Xu
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
| | - Yanping Li
- BGI-Shenzhen, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Yunyun Lv
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Chao Bian
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Xinxin You
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Daiji Endoh
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
| | - Hiroki Teraoka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
| | - Qiong Shi
- BGI-Shenzhen, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
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15
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Wang H, Liu W, Shi F, Huang L, Lian J, Qu L, Cai J, Xu Z. Metabolic pathway engineering for high-level production of 5-hydroxytryptophan in Escherichia coli. Metab Eng 2018; 48:279-287. [PMID: 29933064 DOI: 10.1016/j.ymben.2018.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/27/2018] [Accepted: 06/18/2018] [Indexed: 11/22/2022]
Abstract
Cellular metabolic networks should be carefully balanced using metabolic engineering to produce the desired products at the industrial scale. As the precursor for the biosynthesis of the neurotransmitter serotonin, 5-hydroxytryptophan (5-HTP) is effective in treating a variety of diseases, such as depression, fibromyalgia, obesity, and cerebellar ataxia. Due to the lack of an efficient synthetic method, commercial production of 5-HTP is only achieved by extracting from the seeds of Griffonia Smplicifolia. This study reports efficient microbial production of 5-HTP via metabolically engineered Escherichia coli. Firstly, human tryptophan hydroxylase I (TPH1) gene was functionally expressed. For endogenous supply of the cofactor tetrahydrobiopterin (BH4), human BH4 biosynthesis and regeneration pathway was reconstituted. Whole-cell bioconversion resulted in high-level production of 5-HTP (~1.2 g/L) from 2 g/L L-tryptophan in shake flasks. Further metabolic engineering efforts were employed to achieve 5-HTP biosynthesis from simple carbon sources. The whole biosynthetic pathway was divided into three functional modules, L-tryptophan module, the hydroxylation module, and the BH4 module. By reducing the copy number of L-tryptophan module, replacing TPH1 with a more stable mutant form, and promoter regulation of the BH4 module, 5-HTP was produced at a final titer of 1.3 g/L in the shake flask and 5.1 g/L in a fed-batch fermenter with glycerol as the carbon source, both of which were the highest ever reported for microbial production of 5-HTP.
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Affiliation(s)
- Haijiao Wang
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China; Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Wenqian Liu
- Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Feng Shi
- Shandong Institute for Food and Drug Control, Jinan 250101, China
| | - Lei Huang
- Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China; Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Liang Qu
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jin Cai
- Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhinan Xu
- Key Laboratory of Biomass Chemical Engineering (Education Ministry), College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China; Institute of Biological Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China; Shandong Institute for Food and Drug Control, Jinan 250101, China.
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16
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Backström T, Winberg S. Serotonin Coordinates Responses to Social Stress-What We Can Learn from Fish. Front Neurosci 2017; 11:595. [PMID: 29163002 PMCID: PMC5669303 DOI: 10.3389/fnins.2017.00595] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/10/2017] [Indexed: 12/20/2022] Open
Abstract
Social interaction is stressful and subordinate individuals are often subjected to chronic stress, which greatly affects both their behavior and physiology. In teleost fish the social position of an individual may have long-term effects, such as effects on migration, age of sexual maturation or even sex. The brain serotonergic system plays a key role in coordinating autonomic, behavioral and neuroendocrine stress responses. Social subordination results in a chronic activation of the brain serotonergic system an effect, which seems to be central in the subordinate phenotype. However, behavioral effects of short-term acute activation of the serotonergic system are less obvious. As in other vertebrates, divergent stress coping styles, often referred to as proactive and reactive, has been described in teleosts. As demonstrated by selective breeding, stress coping styles appear to be partly heritable. However, teleost fish are characterized by plasticity, stress coping style being affected by social experience. Again, the brain serotonergic system appears to play an important role. Studies comparing brain gene expression of fish of different social rank and/or displaying divergent stress coping styles have identified several novel factors that seem important for controlling aggressive behavior and stress coping, e.g., histamine and hypocretin/orexin. These may also interact with brain monoaminergic systems, including serotonin.
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Affiliation(s)
- Tobias Backström
- Institute of Integrated Natural Sciences, University Koblenz-Landau, Koblenz, Germany
| | - Svante Winberg
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
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17
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Coates MD, Tekin I, Vrana KE, Mawe GM. Review article: the many potential roles of intestinal serotonin (5-hydroxytryptamine, 5-HT) signalling in inflammatory bowel disease. Aliment Pharmacol Ther 2017; 46:569-580. [PMID: 28737264 DOI: 10.1111/apt.14226] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 04/10/2017] [Accepted: 06/24/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Serotonin (5-hydroxytryptamine, 5-HT) is an important mediator of every major gut-related function. Recent investigations also suggest that 5-HT can influence the development and severity of inflammation within the gut, particularly in the setting of inflammatory bowel disease (IBD). AIM To review the roles that the intestinal serotonin signalling system plays in gut function, with a specific focus on IBD. METHODS We reviewed manuscripts from 1952 to 2017 that investigated and discussed roles for 5-HT signalling in gastrointestinal function and IBD, as well as the influence of inflammation on 5-HT signalling elements within the gut. RESULTS Inflammation appears to affect every major element of intestinal 5-HT signalling, including 5-HT synthesis, release, receptor expression and reuptake capacity. Importantly, many studies (most utilising animal models) also demonstrate that modulation of selective serotonergic receptors (via agonism of 5-HT4 R and antagonism of 5-HT3 R) or 5-HT signal termination (via serotonin reuptake inhibitors) can alter the likelihood and severity of intestinal inflammation and/or its complicating symptoms. However, there are few human studies that have studied these relationships in a targeted manner. CONCLUSIONS Insights discussed in this review have strong potential to lead to new diagnostic and therapeutic tools to improve the management of IBD and other related disorders. Specifically, strategies that focus on modifying the activity of selective serotonin receptors and reuptake transporters in the gut could be effective for controlling disease activity and/or its associated symptoms. Further studies in humans are required, however, to more completely understand the pathophysiological mechanisms underlying the roles of 5-HT in this setting.
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Affiliation(s)
- M D Coates
- Department of Medicine, Division of Gastroenterology & Hepatology, Penn State Hershey Medical Center, Hershey, PA, USA
| | - I Tekin
- Neuroscience Institute, University of California at Santa Barbara, Santa Barbara, CA, USA
| | - K E Vrana
- Department of Pharmacology, Penn State College of Medicine, Hershey, PA, USA
| | - G M Mawe
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, VT, USA
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18
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Mora-Villalobos JA, Zeng AP. Protein and pathway engineering for the biosynthesis of 5-hydroxytryptophan in Escherichia coli. Eng Life Sci 2017; 17:892-899. [PMID: 32624837 DOI: 10.1002/elsc.201700064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/16/2017] [Accepted: 05/29/2017] [Indexed: 11/06/2022] Open
Abstract
The hydroxylation of tryptophan is an important reaction in the biosynthesis of natural products. 5-Hydroxytryptophan (5HTP) is not only an important compound for its pharmaceutical value but also because it is the precursor of other molecules, such as serotonin. In this study, we have extended the metabolism of an E. coli strain to produce 5HTP. Aromatic amino acid hydroxylase from Cupriavidus taiwanensis (CtAAAH) was selected using an in silico structure-based approach. We have predicted and selected several substrate-determining residues using sequence, phylogenetic and functional divergence analyses; we also did rational design on CtAAAH to shift the enzyme preference from phenylalanine to tryptophan. Whole cell bioconversion assays were used to show the effect of predicted sites. In general, all of them decreased the preference toward phenylalanine and increased the tryptophan synthesis activity. The best performer, CtAAAH-W192F, was transformed into a strain that had the tryptophanase gene disrupted and carried a human tetrahydrobiopterin (BH4) regeneration pathway. The resulting strain was capable of synthesizing 2.5 mM 5HTP after 24 hours. This work demonstrates the application of computational approaches for protein engineering and further coupling with the bacterial metabolism.
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Affiliation(s)
- José-Aníbal Mora-Villalobos
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany.,Centro Nacional de Innovaciones Biotecnológicas Centro Nacional de Alta Tecnología San Jose Costa Rica
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering Hamburg University of Technology Hamburg Germany
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19
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Abstract
Comparative models suggest that effects of dietary tryptophan (Trp) on brain serotonin (5-hydroxytryptamine; 5-HT) neurochemistry and stress responsiveness are present throughout the vertebrate lineage. Moreover, hypothalamic 5-HT seems to play a central role in control of the neuroendocrine stress axis in all vertebrates. Still, recent fish studies suggest long-term effects of dietary Trp on stress responsiveness, which are independent of hypothalamic 5-HT. Here, we investigated if dietary Trp treatment may result in long-lasting effects on stress responsiveness, including changes in plasma cortisol levels and 5-HT neurochemistry in the telencephalon and hypothalamus of Atlantic salmon. Fish were fed diets containing one, two or three times the Trp content in normal feed for 1 week. Subsequently, fish were reintroduced to control feed and were exposed to acute crowding stress for 1 h, 8 and 21 d post Trp treatment. Generally, acute crowding resulted in lower plasma cortisol levels in fish treated with 3×Trp compared with 1×Trp- and 2×Trp-treated fish. The same general pattern was reflected in telencephalic 5-HTergic turnover, for which 3×Trp-treated fish showed decreased values compared with 2×Trp-treated fish. These long-term effects on post-stress plasma cortisol levels and concomitant 5-HT turnover in the telencephalon lends further support to the fact that the extrahypothalamic control of the neuroendocrine stress response is conserved within the vertebrate lineage. Moreover, they indicate that trophic/structural effects in the brain underlie the effects of dietary Trp treatment on stress reactivity.
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20
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Kim WT, Yun SJ, Yan C, Jeong P, Kim YH, Lee IS, Kang HW, Park S, Moon SK, Choi YH, Choi YD, Kim IY, Kim J, Kim WJ. Metabolic Pathway Signatures Associated with Urinary Metabolite Biomarkers Differentiate Bladder Cancer Patients from Healthy Controls. Yonsei Med J 2016; 57:865-71. [PMID: 27189278 PMCID: PMC4951461 DOI: 10.3349/ymj.2016.57.4.865] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/22/2015] [Accepted: 10/22/2015] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Our previous high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry study identified bladder cancer (BCA)-specific urine metabolites, including carnitine, acylcarnitines, and melatonin. The objective of the current study was to determine which metabolic pathways are perturbed in BCA, based on our previously identified urinary metabolome. MATERIALS AND METHODS A total of 135 primary BCA samples and 26 control tissue samples from healthy volunteers were analyzed. The association between specific urinary metabolites and their related encoding genes was analyzed. RESULTS Significant alterations in the carnitine-acylcarnitine and tryptophan metabolic pathways were detected in urine specimens from BCA patients compared to those of healthy controls. The expression of eight genes involved in the carnitine-acylcarnitine metabolic pathway (CPT1A, CPT1B, CPT1C, CPT2, SLC25A20, and CRAT) or tryptophan metabolism (TPH1 and IDO1) was assessed by RT-PCR in our BCA cohort (n=135). CPT1B, CPT1C, SLC25A20, CRAT, TPH1, and IOD1 were significantly downregulated in tumor tissues compared to normal bladder tissues (p<0.05 all) of patients with non-muscle invasive BCA, whereas CPT1B, CPT1C, CRAT, and TPH1 were downregulated in those with muscle invasive BCA (p<0.05), with no changes in IDO1 expression. CONCLUSION Alterations in the expression of genes associated with the carnitine-acylcarnitine and tryptophan metabolic pathways, which were the most perturbed pathways in BCA, were determined.
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Affiliation(s)
- Won Tae Kim
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
- Department of Urology, Graduate School of Medicine, Yonsei University, Seoul, Korea
| | - Seok Joong Yun
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Chunri Yan
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Pildu Jeong
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Ye Hwan Kim
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Il Seok Lee
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Ho Won Kang
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea
| | - Sunghyouk Park
- College of Pharmacy, Natural Product Research Institute, Seoul National University, Seoul, Korea
| | - Sung Kwon Moon
- School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Yung Hyun Choi
- Department of Biochemistry, Dongeui University College of Oriental Medicine, Busan, Korea
| | - Young Deuk Choi
- Department of Urology, Graduate School of Medicine, Yonsei University, Seoul, Korea
| | - Isaac Yi Kim
- Section of Urological Oncology, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Jayoung Kim
- Department of Surgery, Harvard Medical School, Boston, MA, USA.
- Cancer Biology Division, Departments of Surgery and Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Wun Jae Kim
- Department of Urology, Chungbuk National University College of Medicine, Cheongju, Korea.
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21
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Winberg S, Thörnqvist PO. Role of brain serotonin in modulating fish behavior. Curr Zool 2016; 62:317-323. [PMID: 29491919 PMCID: PMC5804243 DOI: 10.1093/cz/zow037] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 02/17/2016] [Indexed: 12/22/2022] Open
Abstract
The organization of the brain serotonergic system appears to have been highly conserved across the vertebrate subphylum. In fish as well as in other vertebrates, brain serotonin (5-HT), mainly acts as a neuromodulator with complex effects on multiple functions. It is becoming increasingly clear that acute and chronic increase in brain 5-HT neurotransmission have very different effects. An acute 5-HT activation, which is seen in both winners and losers of agonistic interactions, could be related to a general arousal effect, whereas the chronic activation observed in subordinate fish is clearly linked to the behavioral inhibition displayed by these individuals. Fish displaying divergent stress coping styles (proactive vs. reactive) differ in 5-HT functions. In teleost fish, brain monoaminergic function is also related to life history traits.
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Affiliation(s)
- Svante Winberg
- Department of Neuroscience, Comparative Behavioral Neuroendocrinology Lab, Uppsala University, Box 593, 751 24 Uppsala, Sweden
| | - Per-Ove Thörnqvist
- Department of Neuroscience, Comparative Behavioral Neuroendocrinology Lab, Uppsala University, Box 593, 751 24 Uppsala, Sweden
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23
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Fu HJ, Zhao Y, Zhou YR, Bao BH, Du Y, Li JX. Ursolic acid derivatives as bone anabolic agents targeted to tryptophan hydroxylase 1 (Tph-1). Eur J Pharm Sci 2015; 76:33-47. [PMID: 25930119 DOI: 10.1016/j.ejps.2015.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/15/2015] [Accepted: 04/26/2015] [Indexed: 01/28/2023]
Abstract
Tryptophan hydroxylase 1 (Tph-1) initiates the biosynthesis of peripheral serotonin. As peripheral serotonin suppresses bone formation, inhibitor of Tph-1 provides a useful tool to discover anabolic agents for osteoporosis. In the present study, series of ursolic acid (UA) derivatives were synthesized, and their inhibitory activity on serotonin biosynthesis and cytotoxicity were evaluated. Among the derivatives, 8d with potent inhibitory activity on serotonin was applied for further research. The data revealed that 8d significantly inhibited protein and mRNA expressions of Tph-1, and an SPR study indicated that 8d directly interacted to Tph-1 with a binding affinity of KD=15.09μM. Oral administration of 8d significantly prevented bone loss via suppressing serotonin biosynthesis without estrogenic side-effects in ovariectomized (OVX) rats.
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Affiliation(s)
- Hai-Jian Fu
- State Key Lab of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, PR China
| | - Yang Zhao
- State Key Lab of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, PR China
| | - Yu-Ren Zhou
- State Key Lab of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, PR China
| | - Bei-Hua Bao
- State Key Lab of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, PR China
| | - Yun Du
- State Key Lab of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, PR China
| | - Jian-Xin Li
- State Key Lab of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210093, PR China.
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Rajathei DM, Preethi J, Singh HK, Rajan KE. Molecular docking of bacosides with tryptophan hydroxylase: a model to understand the bacosides mechanism. NATURAL PRODUCTS AND BIOPROSPECTING 2014; 4:251-255. [PMID: 25089244 PMCID: PMC4111882 DOI: 10.1007/s13659-014-0031-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 06/30/2014] [Indexed: 06/03/2023]
Abstract
Tryptophan hydroxylase (TPH) catalyses l-tryptophan into 5-hydroxy-l-tryptophan, which is the first and rate-limiting step of serotonin (5-HT) biosynthesis. Earlier, we found that TPH2 up-regulated in the hippocampus of postnatal rats after the oral treatment of Bacopa monniera leaf extract containing the active compound bacosides. However, the knowledge about the interactions between bacosides with TPH is limited. In this study, we take advantage of in silico approach to understand the interaction of bacoside-TPH complex using three different docking algorithms such as HexDock, PatchDock and AutoDock. All these three algorithms showed that bacoside A and A3 well fit into the cavity consists of active sites. Further, our analysis revealed that major active compounds bacoside A3 and A interact with different residues of TPH through hydrogen bond. Interestingly, Tyr235, Thr265 and Glu317 are the key residues among them, but none of them are either at tryptophan or BH4 binding region. However, its note worthy to mention that Tyr 235 is a catalytic sensitive residue, Thr265 is present in the flexible loop region and Glu317 is known to interacts with Fe. Interactions with these residues may critically regulate TPH function and thus serotonin synthesis. Our study suggested that the interaction of bacosides (A3/A) with TPH might up-regulate its activity to elevate the biosynthesis of 5-HT, thereby enhances learning and memory formation.
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Affiliation(s)
- David Mary Rajathei
- Department of Bioinformtics, Bharathidasan University, Tiruchirappalli, 620024 India
| | - Jayakumar Preethi
- Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024 India
| | - Hemant K. Singh
- Laboratories of CNS Disorder, Learning & Memory, Division of Pharmacology, Central Drug Research Institute, Lucknow, 226031 India
| | - Koilmani Emmanuvel Rajan
- Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620024 India
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Autoantibodies against aromatic amino acid hydroxylases in patients with autoimmune polyendocrine syndrome type 1 target multiple antigenic determinants and reveal regulatory regions crucial for enzymatic activity. Immunobiology 2013. [DOI: 10.1016/j.imbio.2012.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Roberts KM, Fitzpatrick PF. Mechanisms of tryptophan and tyrosine hydroxylase. IUBMB Life 2013; 65:350-7. [PMID: 23441081 DOI: 10.1002/iub.1144] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 01/02/2013] [Indexed: 11/11/2022]
Abstract
The aromatic amino acid hydroxylases tryptophan hydroxylase and tyrosine hydroxylase are responsible for the initial steps in the formation of serotonin and the catecholamine neurotransmitters, respectively. Both enzymes are nonheme iron-dependent monooxygenases that catalyze the insertion of one atom of molecular oxygen onto the aromatic ring of their amino acid substrates, using a tetrahydropterin as a two electron donor to reduce the second oxygen atom to water. This review discusses the current understanding of the catalytic mechanism of these two enzymes. The reaction occurs as two sequential half reactions: a reaction between the active site iron, oxygen, and the tetrahydropterin to form a reactive Fe(IV) O intermediate and hydroxylation of the amino acid by the Fe(IV) O. The mechanism of formation of the Fe(IV) O is unclear; however, considerable evidence suggests the formation of an Fe(II) -peroxypterin intermediate. The amino acid is hydroxylated by the Fe(IV) O intermediate in an electrophilic aromatic substitution mechanism.
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Affiliation(s)
- Kenneth M Roberts
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78228, USA
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Daubner SC, Avila A, Bailey JO, Barrera D, Bermudez JY, Giles DH, Khan CA, Shaheen N, Thompson JW, Vasquez J, Oxley SP, Fitzpatrick PF. Mutagenesis of a specificity-determining residue in tyrosine hydroxylase establishes that the enzyme is a robust phenylalanine hydroxylase but a fragile tyrosine hydroxylase. Biochemistry 2013; 52:1446-55. [PMID: 23368961 DOI: 10.1021/bi400031n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The aromatic amino acid hydroxylases tyrosine hydroxylase (TyrH) and phenylalanine hydroxylase (PheH) have essentially identical active sites; however, PheH is nearly incapable of hydroxylating tyrosine, while TyrH can readily hydroxylate both tyrosine and phenylalanine. Previous studies have indicated that Asp425 of TyrH is important in determining the substrate specificity of that enzyme [Daubner, S. C., Melendez, J., and Fitzpatrick, P. F. (2000) Biochemistry 39, 9652-9661]. Alanine-scanning mutagenesis of amino acids 423-427, a mobile loop containing Asp425, shows that only mutagenesis of Asp425 alters the activity of the enzyme significantly. Saturation mutagenesis of Asp425 results in large (up to 10(4)) decreases in the V(max) and V(max)/K(tyr) values for tyrosine hydroxylation, but only small decreases or even increases in the V(max) and V(max)/K(phe) values for phenylalanine hydroxylation. The decrease in the tyrosine hydroxylation activity of the mutant proteins is due to an uncoupling of tetrahydropterin oxidation from amino acid hydroxylation with tyrosine as the amino acid substrate. In contrast, with the exception of the D425W mutant, the extent of coupling of tetrahydropterin oxidation and amino acid hydroxylation is unaffected or increases with phenylalanine as the amino acid substrate. The decrease in the V(max) value with tyrosine as the substrate shows a negative correlation with the hydrophobicity of the amino acid residue at position 425. The results are consistent with a critical role of Asp425 being to prevent a hydrophobic interaction that results in a restricted active site in which hydroxylation of tyrosine does not occur.
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Affiliation(s)
- S Colette Daubner
- Department of Biological Sciences, St. Mary's University, San Antonio, Texas 78228, United States.
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Roberts KM, Pavon JA, Fitzpatrick PF. Kinetic mechanism of phenylalanine hydroxylase: intrinsic binding and rate constants from single-turnover experiments. Biochemistry 2013; 52:1062-73. [PMID: 23327364 DOI: 10.1021/bi301675e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phenylalanine hydroxylase (PheH) catalyzes the key step in the catabolism of dietary phenylalanine, its hydroxylation to tyrosine using tetrahydrobiopterin (BH(4)) and O(2). A complete kinetic mechanism for PheH was determined by global analysis of single-turnover data in the reaction of PheHΔ117, a truncated form of the enzyme lacking the N-terminal regulatory domain. Formation of the productive PheHΔ117-BH(4)-phenylalanine complex begins with the rapid binding of BH(4) (K(d) = 65 μM). Subsequent addition of phenylalanine to the binary complex to form the productive ternary complex (K(d) = 130 μM) is approximately 10-fold slower. Both substrates can also bind to the free enzyme to form inhibitory binary complexes. O(2) rapidly binds to the productive ternary complex; this is followed by formation of an unidentified intermediate, which can be detected as a decrease in absorbance at 340 nm, with a rate constant of 140 s(-1). Formation of the 4a-hydroxypterin and Fe(IV)O intermediates is 10-fold slower and is followed by the rapid hydroxylation of the amino acid. Product release is the rate-determining step and largely determines k(cat). Similar reactions using 6-methyltetrahydropterin indicate a preference for the physiological pterin during hydroxylation.
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Affiliation(s)
- Kenneth M Roberts
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229, USA
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Schallreuter KU, Salem MAEL, Gibbons NCJ, Martinez A, Slominski R, Lüdemann J, Rokos H. Blunted epidermal L-tryptophan metabolism in vitiligo affects immune response and ROS scavenging by Fenton chemistry, part 1: Epidermal H2O2/ONOO(-)-mediated stress abrogates tryptophan hydroxylase and dopa decarboxylase activities, leading to low serotonin and melatonin levels. FASEB J 2012; 26:2457-70. [PMID: 22415302 DOI: 10.1096/fj.11-197137] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vitiligo is characterized by a progressive loss of inherited skin color. The cause of the disease is still unknown. To date, there is accumulating in vivo and in vitro evidence for massive oxidative stress via hydrogen peroxide (H(2)O(2)) and peroxynitrite (ONOO(-)) in the skin of affected individuals. Autoimmune etiology is the favored theory. Since depletion of the essential amino acid L-tryptophan (Trp) affects immune response mechanisms, we here looked at epidermal Trp metabolism via tryptophan hydroxylase (TPH) with its downstream cascade, including serotonin and melatonin. Our in situ immunofluorescence and Western blot data reveal significantly lower TPH1 expression in patients with vitiligo. Expression is also low in melanocytes and keratinocytes under in vitro conditions. Although in vivo Fourier transform-Raman spectroscopy proves the presence of 5-hydroxytryptophan, epidermal TPH activity is completely absent. Regulation of TPH via microphthalmia-associated transcription factor and L-type calcium channels is severely affected. Moreover, dopa decarboxylase (DDC) expression is significantly lower, in association with decreased serotonin and melatonin levels. Computer simulation supports H(2)O(2)/ONOO(-)-mediated oxidation/nitration of TPH1 and DDC, affecting, in turn, enzyme functionality. Taken together, our data point to depletion of epidermal Trp by Fenton chemistry and exclude melatonin as a relevant contributor to epidermal redox balance and immune response in vitiligo.
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Affiliation(s)
- Karin U Schallreuter
- Institute for Pigmentary Disorders, E. M. Arndt University, Greifswald, Germany.
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Kino K, Hara R, Nozawa A. Enhancement of L-tryptophan 5-hydroxylation activity by structure-based modification of L-phenylalanine 4-hydroxylase from Chromobacterium violaceum. J Biosci Bioeng 2010; 108:184-9. [PMID: 19664549 DOI: 10.1016/j.jbiosc.2009.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2008] [Revised: 04/02/2009] [Accepted: 04/03/2009] [Indexed: 10/20/2022]
Abstract
The objective of this study was to enhance l-tryptophan hydroxylation activity of l-phenylalanine 4-hydroxylase. It had been known that l-phenylalanine 4-hydroxylase from Chromobacterium violaceum could convert l-tryptophan to 5-hydroxy-l-tryptophan and l-phenylalanine to l-tyrosine; however, the activity for l-tryptophan was extremely low compared to l-phenylalanine activity levels. We used the information on the crystal structures of aromatic amino acid hydroxylases to generate C. violaceuml-phenylalanine 4-hydroxylase with high l-tryptophan hydroxylating activity. In silico structural modeling analysis suggested that hydrophobic and/or stacking interactions with the substrate and cofactor at L101 and W180 in C. violaceuml-phenylalanine 4-hydroxylase would increase hydroxylation activity. Based on this hypothesis, we introduced a saturation mutagenesis towards these sites followed by the evaluation of 5-hydroxy-l-tryptophan productivity using a modified Gibbs assay. Three and nine positive mutants were obtained from the L101 and W180 mutant libraries, respectively. Among the mutants, L101Y and W180F showed the highest l-tryptophan hydroxylation activity at the respective residues. Steady-state kinetic analysis revealed that k(cat) values for l-tryptophan hydroxylation were increased from 0.40 (wild-type) to 1.02 (L101Y) and 0.51 s(-1) (W180F). In addition, the double mutant (L101Y-W180F) displayed higher l-tryptophan hydroxylation activity than the wild-type and the W180F and L101Y mutants. The k(cat) value of L101Y-W180F increased to 2.08 s(-1), showing a 5.2-fold increase compared to wild-type enzyme levels.
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Affiliation(s)
- Kuniki Kino
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
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The Aromatic Amino Acid Hydroxylase Mechanism: A Perspective From Computational Chemistry. ADVANCES IN INORGANIC CHEMISTRY 2010. [DOI: 10.1016/s0898-8838(10)62011-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Haahr LT, Jensen KP, Boesen J, Christensen HEM. Experimentally calibrated computational chemistry of tryptophan hydroxylase: trans influence, hydrogen-bonding, and 18-electron rule govern O2-activation. J Inorg Biochem 2009; 104:136-45. [PMID: 19939457 DOI: 10.1016/j.jinorgbio.2009.10.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 10/09/2009] [Accepted: 10/16/2009] [Indexed: 10/20/2022]
Abstract
Insight into the nature of oxygen activation in tryptophan hydroxylase has been obtained from density functional computations. Conformations of O(2)-bound intermediates have been studied with oxygen trans to glutamate and histidine, respectively. An O(2)-adduct with O(2)trans to histidine (O(his)) and a peroxo intermediate with peroxide trans to glutamate (P(glu)) were found to be consistent (0.57-0.59mm/s) with experimental Mössbauer isomer shifts (0.55mm/s) and had low computed free energies. The weaker trans influence of histidine is shown to give rise to a bent O(2) coordination mode with O(2) pointing towards the cofactor and a more activated O-O bond (1.33A) than in O(glu) (1.30A). It is shown that the cofactor can hydrogen bond to O(2) and activate the O-O bond further (from 1.33 to 1.38A). The O(his) intermediate leads to a ferryl intermediate (F(his)) with an isomer shift of 0.34mm/s, also consistent with the experimental value (0.25mm/s) which we propose as the structure of the hydroxylating intermediate, with the tryptophan substrate well located for further reaction 3.5A from the ferryl group. Based on the optimized transition states, the activation barriers for the two paths (glu and his) are similar, so a two-state scenario involving O(his) and P(glu) is possible. A structure of the activated deoxy state which is high-spin implies that the valence electron count has been lowered from 18 to 16 (glutamate becomes bidentate), giving a "green light" that invites O(2)-binding. Our mechanism of oxygen activation in tryptophan hydroxylase does not require inversion of spin, which may be an important observation.
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Affiliation(s)
- Laerke T Haahr
- Technical University of Denmark, DTU Chemistry, Kemitorvet 207, 2800 Kgs. Lyngby, DK, Denmark
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33
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Windahl MS, Boesen J, Karlsen PE, Christensen HEM. Expression, Purification and Enzymatic Characterization of the Catalytic Domains of Human Tryptophan Hydroxylase Isoforms. Protein J 2009; 28:400-6. [DOI: 10.1007/s10930-009-9207-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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McKinney JA, Turel B, Winge I, Knappskog PM, Haavik J. Functional properties of missense variants of human tryptophan hydroxylase 2. Hum Mutat 2009; 30:787-94. [PMID: 19319927 DOI: 10.1002/humu.20956] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tryptophan hydroxylase 2 (TPH2) catalyzes the rate-limiting step in serotonin biosynthesis in the nervous system. Several variants of human TPH2 have been reported to be associated with a spectrum of neuropsychiatric disorders such as unipolar major depression, bipolar disorder, suicidality, and attention-deficit/hyperactivity disorder (ADHD). We used three different expression systems: rabbit reticulocyte lysate, Escherichia coli, and human embryonic kidney cells, to identify functional effects of all human TPH2 missense variants reported to date. The properties of mutants affecting the regulatory domain, that is, p.Leu36Val, p.Leu36Pro, p.Ser41Tyr, and p.Arg55Cys, were indistinguishable from the wild-type (WT). Moderate loss-of-function effects were observed for mutants in the catalytic and oligomerization domains, that is, p.Pro206Ser, p.Ala328Val, p.Arg441His, and p.Asp479Glu, which were manifested via stability and solubility effects, whereas p.Arg303Trp had severely reduced solubility and was completely inactive. All variants were tested as substrates for protein kinase A and were found to have similar phosphorylation stoichiometries. A standardized assay protocol as described here for activity and solubility screening should also be useful for determining properties of other TPH2 variants that will be discovered in the future.
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35
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Windahl MS, Petersen CR, Christensen HEM, Harris P. Crystal structure of tryptophan hydroxylase with bound amino acid substrate. Biochemistry 2008; 47:12087-94. [PMID: 18937498 DOI: 10.1021/bi8015263] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tryptophan hydroxylase (TPH) is a mononuclear non-heme iron enzyme, which catalyzes the reaction between tryptophan, O 2, and tetrahydrobiopterin (BH 4) to produce 5-hydroxytryptophan and 4a-hydroxytetrahydrobiopterin. This is the first and rate-limiting step in the biosynthesis of the neurotransmitter and hormone serotonin (5-hydroxytryptamine). We have determined the 1.9 A resolution crystal structure of the catalytic domain (Delta1-100/Delta415-445) of chicken TPH isoform 1 (TPH1) in complex with the tryptophan substrate and an iron-bound imidazole. This is the first structure of any aromatic amino acid hydroxylase with bound natural amino acid substrate. The iron coordination can be described as distorted trigonal bipyramidal coordination with His273, His278, and Glu318 (partially bidentate) and one imidazole as ligands. The tryptophan stacks against Pro269 with a distance of 3.9 A between the iron and the tryptophan Czeta3 atom that is hydroxylated. The binding of tryptophan and maybe the imidazole has caused the structural changes in the catalytic domain compared to the structure of the human TPH1 without tryptophan. The structure of chicken TPH1 is more compact, and the loops of residues Leu124-Asp139 and Ile367-Thr369 close around the active site. Similar structural changes are seen in the catalytic domain of phenylalanine hydroxylase (PAH) upon binding of substrate analogues norleucine and thienylalanine to the PAH.BH 4 complex. In fact, the chicken TPH1.Trp.imidazole structure resembles the PAH.BH 4.thienylalanine structure more (root-mean-square deviation for Calpha atoms of 0.90 A) than the human TPH1 structure (root-mean-square deviation of 1.47 A).
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Affiliation(s)
- Michael S Windahl
- Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
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36
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Activation and stabilization of human tryptophan hydroxylase 2 by phosphorylation and 14-3-3 binding. Biochem J 2008; 410:195-204. [PMID: 17973628 DOI: 10.1042/bj20071033] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
TPH (tryptophan hydroxylase) catalyses the rate-limiting step in the synthesis of serotonin, and exists in two isoforms: TPH1, mainly found in peripheral tissues and the pineal body, and TPH2, a neuronal form. In the present study human TPH2 was expressed in Escherichia coli and in HEK (human embryonic kidney)-293 cells and phosphorylated using several different mammalian protein kinases. TPH2 was rapidly phosphorylated to a stoichiometry of 2 mol of phosphate/mol of subunit by PKA (protein kinase A), but only to a stoichiometry of 0.2 by Ca(2+)/calmodulin dependent protein kinase II. Both kinases phosphorylated Ser(19), but PKA also phosphorylated Ser(104), as determined by MS, phosphospecific antibodies and site-directed mutagenesis of several possible phosphorylation sites, i.e. Ser(19), Ser(99), Ser(104) and Ser(306). On average, purified TPH2 WT (wild-type) was activated by 30% after PKA phosphorylation and studies of the mutant enzymes showed that enzyme activation was mainly due to phosphorylation at Ser(19). This site was phosphorylated to a stoichiometry of up to 50% in HEK-293 cells expressing TPH2, and the enzyme activity and phosphorylation stoichiometry was further increased upon treatment with forskolin. Purified PKA-phosphorylated TPH2 bound to the 14-3-3 proteins gamma, epsilon and BMH1 with high affinity, causing a further increase in enzyme stability and activity. This indicates that 14-3-3 proteins could play a role in consolidating and strengthening the effects of phosphorylation on TPH2 and that they may be important for the regulation of serotonin function in the nervous system.
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A simple two step procedure for purification of the catalytic domain of chicken tryptophan hydroxylase 1 in a form suitable for crystallization. Protein Expr Purif 2008; 57:116-26. [DOI: 10.1016/j.pep.2007.10.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 10/12/2007] [Accepted: 10/18/2007] [Indexed: 11/24/2022]
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Winge I, McKinney JA, Knappskog PM, Haavik J. Characterization of wild-type and mutant forms of human tryptophan hydroxylase 2. J Neurochem 2006; 100:1648-57. [PMID: 17181551 DOI: 10.1111/j.1471-4159.2006.04290.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tryptophan hydroxylase (TPH) catalyses the rate-limiting step in the biosynthesis of serotonin. In vertebrates, the homologous genes tph1 and tph2 encode two different enzymes with distinct patterns of expression, enzyme kinetics and regulation. Variants of TPH2 have recently reported to be associated with reduced serotonin production and behavioural alterations in man and mice. We have produced the human forms of these enzymes in Esherichia coli and in human embryonic kidney cell lines (HEK293) and examined the effects of mutations on their heterologous expression levels, solubility, thermal stability, secondary structure, and catalytic properties. Pure human TPH2 P449R (corresponds to mouse P447R) had comparable catalytic activity (V(max)) and solubility relative to the wild type, but had decreased thermal stability; whereas human TPH2 R441H had decreased activity, solubility and stability. Thus, we consider the variations in kinetic values between wild-type and TPH2 mutants to be of secondary importance to their effects on protein stability and solubility. These findings provide potential molecular explanations for disorders related to the central serotonergic system, such as depression or suicidal behaviour.
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Affiliation(s)
- Ingeborg Winge
- Department of Biomedicine, Section of Biochemistry and Molecular Biology, University of Bergen, Norway
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Pavon JA, Fitzpatrick PF. Insights into the catalytic mechanisms of phenylalanine and tryptophan hydroxylase from kinetic isotope effects on aromatic hydroxylation. Biochemistry 2006; 45:11030-7. [PMID: 16953590 PMCID: PMC1945167 DOI: 10.1021/bi0607554] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phenylalanine hydroxylase (PheH) and tryptophan hydroxylase (TrpH) catalyze the aromatic hydroxylation of phenylalanine and tryptophan, forming tyrosine and 5-hydroxytryptophan, respectively. The reactions of PheH and TrpH have been investigated with [4-(2)H]-, [3,5-(2)H(2)]-, and (2)H(5)-phenylalanine as substrates. All (D)k(cat) values are normal with Delta117PheH, the catalytic core of rat phenylalanine hydroxylase, ranging from 1.12-1.41. In contrast, for Delta117PheH V379D, a mutant protein in which the stoichiometry between tetrahydropterin oxidation and amino acid hydroxylation is altered, the (D)k(cat) value with [4-(2)H]-phenylalanine is 0.92 but is normal with [3,5-(2)H(2)]-phenylalanine. The ratio of tetrahydropterin oxidation to amino acid hydroxylation for Delta117PheH V379D shows a similar inverse isotope effect with [4-(2)H]-phenylalanine. Intramolecular isotope effects, determined from the deuterium contents of the tyrosine formed from [4-(2)H]-and [3,5(2)H(2)]-phenylalanine, are identical for Delta117PheH and Delta117PheH V379D, suggesting that steps subsequent to oxygen addition are unaffected in the mutant protein. The inverse effects are consistent with the reaction of an activated ferryl-oxo species at the para position of the side chain of the amino acid to form a cationic intermediate. The normal effects on the (D)k(cat) value for the wild-type enzyme are attributed to an isotope effect of 5.1 on the tautomerization of a dienone intermediate to tyrosine with a rate constant 6- to7-fold that for hydroxylation. In addition, there is a slight ( approximately 34%) preference for the loss of the hydrogen originally at C4 of phenylalanine. With (2)H(5)-indole-tryptophan as a substrate for Delta117PheH, the (D)k(cat) value is 0.89, consistent with hydroxylation being rate-limiting in this case. When deuterated phenylalanines are used as substrates for TrpH, the (D)k(cat) values are within error of those for Delta117PheH V379D. Overall, these results are consistent with the aromatic amino acid hydroxylases all sharing the same chemical mechanism, but with the isotope effect for hydroxylation by PheH being masked by tautomerization of an enedione intermediate to tyrosine.
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Affiliation(s)
- Jorge Alex Pavon
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, USA
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Carkaci-Salli N, Flanagan JM, Martz MK, Salli U, Walther DJ, Bader M, Vrana KE. Functional Domains of Human Tryptophan Hydroxylase 2 (hTPH2). J Biol Chem 2006; 281:28105-12. [PMID: 16864580 DOI: 10.1074/jbc.m602817200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in serotonin biosynthesis. A novel gene, termed TPH2, has recently been described. This gene is preferentially expressed in the central nervous system, while the original TPH1 is the peripheral gene. We have expressed human tryptophan hydroxylase 2 (hTPH2) and two deletion mutants (NDelta150 and NDelta150/CDelta24) using isopropyl beta-D-thiogalactopyranoside-free autoinduction in Escherichia coli. This expression system produced active wild type TPH2 with relatively low solubility. The solubility was increased for mutants lacking the NH(2)-terminal regulatory domain. The solubility of hTPH2, NDelta150, and NDelta150/CDelta24 are 6.9, 62, and 97.5%, respectively. Removal of the regulatory domain also produced a more than 6-fold increase in enzyme stability (t((1/2)) at 37 degrees C). The wild type hTPH2, like other members of the aromatic amino acid hydroxylase superfamily, exists as a homotetramer (236 kDa on size exclusion chromatography). Similarly, NDelta150 also migrates as a tetramer (168 kDa). In contrast, removal of the NH(2)-terminal domain and the COOH-terminal, putative leucine zipper tetramerization domain produces monomeric enzyme (39 kDa). Interestingly, removal of the NH(2)-terminal regulatory domain did not affect the Michaelis constants for either substrate but did increase V(max) values. These data identify the NH(2)-terminal regulatory domain as the source of hTPH2 instability and reduced solubility.
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Affiliation(s)
- Nurgul Carkaci-Salli
- Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033-2360, USA
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Daubner SC, McGinnis JT, Gardner M, Kroboth SL, Morris AR, Fitzpatrick PF. A flexible loop in tyrosine hydroxylase controls coupling of amino acid hydroxylation to tetrahydropterin oxidation. J Mol Biol 2006; 359:299-307. [PMID: 16618490 PMCID: PMC1945210 DOI: 10.1016/j.jmb.2006.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2006] [Revised: 03/08/2006] [Accepted: 03/08/2006] [Indexed: 10/24/2022]
Abstract
The role of a polypeptide loop in tyrosine hydroxylase (TyrH) whose homolog in phenylalanine hydroxylase (PheH) takes on a different conformation when substrates are bound has been studied using site-directed mutagenesis. The loop spans positions 177 to 191; alanine was introduced into those positions, introducing one alanine substitution per TyrH variant. Mutagenesis of residues in the center of the loop resulted in alterations in the KM values for substrates, the Vmax value for dihydroxyphenylalanine (DOPA) synthesis, and the coupling of tetrahydropterin oxidation to tyrosine hydroxylation. The variant with the most altered KM value for 6-methyltetrahydropterin was TyrH F184A. The variants with the most affected K(tyr) values were those with substitutions in the center of the loop, TyrH K183A, F184A, D185A, P186A and D187A. These five variants also had the most reduced Vmax values for DOPA synthesis. Alanine substitution in positions 182-186 resulted in lowered ratios of tyrosine hydroxylation to tetrahydropterin oxidation. TyrH F184Y and PheH Y138F, variants with the residue at the center of the loop substituted with the residue present at the homologous position in the other hydroxylase, were also studied. The V/K(tyr) to V/K(phe) ratios for these variants were altered significantly, but the results did not suggest that F184 of TyrH or Y138 of PheH plays a dominant role in determining amino acid substrate specificity.
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Affiliation(s)
- S Colette Daubner
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA
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Sakowski SA, Geddes TJ, Kuhn DM. Mouse tryptophan hydroxylase isoform 2 and the role of proline 447 in enzyme function. J Neurochem 2006; 96:758-65. [PMID: 16405505 DOI: 10.1111/j.1471-4159.2005.03604.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the synthesis of the neurotransmitter serotonin (5-HT). Once thought to be a single gene product, TPH is now known to exist in two isoforms. Isoform 1 (TPH1) is found in the pineal gland and gut, and isoform 2 (TPH2) is selectively expressed in brain. A single-nucleotide polymorphism in TPH2 results in a proline-to-arginine mutation at residue 447 and substantially lowers catalytic activity. In view of the importance of TPH in determining brain 5-HT function, we cloned TPH2 and produced the P447R mutant to assess the importance of this proline in enzyme function. Catalytically active TPH2 and the P447R mutant were expressed at the predicted subunit molecular mass of 56 kDa. The P447R mutant expressed less than 50% of the activity of TPH2. Mutation of this conserved proline in TPH1 (P403R) also resulted in an enzyme with significantly lower activity than the wild-type enzyme. The P447R mutant had a V(max) 50% lower than that of TPH2. The P447R mutation did not alter the oligomeric assembly of the protein, nor change its responsiveness to cysteine modification. The P447R mutation did not alter enzyme substrate specificity or stability, but conferred slightly enhanced sensitivity to inhibition by dopamine and diminished sensitivity to iron in catalysis. The conserved proline in TPH (residue 447 in TPH2 and 403 in TPH1) plays an important role in enzyme function by regulating V(max) of the catalytic reaction.
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Affiliation(s)
- Stacey A Sakowski
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
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Abu-Omar MM, Loaiza A, Hontzeas N. Reaction mechanisms of mononuclear non-heme iron oxygenases. Chem Rev 2005; 105:2227-52. [PMID: 15941213 DOI: 10.1021/cr040653o] [Citation(s) in RCA: 447] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mahdi M Abu-Omar
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA.
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Fossbakk A, Haavik J. An oxygraphic method for determining kinetic properties and catalytic mechanism of aromatic amino acid hydroxylases. Anal Biochem 2005; 343:100-5. [PMID: 15963939 DOI: 10.1016/j.ab.2005.04.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 04/27/2005] [Accepted: 04/29/2005] [Indexed: 11/28/2022]
Abstract
We have developed a simple and versatile oxygraphic assay procedure that can be used for determination of kinetic constants and enzyme reaction mechanisms of wild-type and mutant aromatic amino acid hydroxylases. The oxygen concentration and rate of oxygen consumption were measured continuously throughout the enzyme reaction, while aliquots of the reaction mixture were removed at regular intervals for measurement of other substrates and products. Using (6R)-tetrahydrobiopterin as electron donor in the phenylalanine hydroxylase (PAH) reaction, a stable stoichiometry of 1:1 was obtained between the amount of oxygen consumed and the tyrosine formation. In comparison, low and variable coupling efficiency values between oxygen consumption and tyrosine formation were found using the parent unsubstituted tetrahydropterin. The application of this assay procedure to study mechanisms of disease-associated mutations was also demonstrated. Thus, the phenylketonuria-associated PAH mutant R158Q had a coupling efficiency of about 80%, compared to the wild-type enzyme under similar conditions. Furthermore, the amount of H(2)O(2) produced in the reaction catalyzed by R158Q PAH was about four times higher than the amount produced by the wild-type PAH, demonstrating a possible pathogenetic mechanism of the mutant enzyme.
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Affiliation(s)
- Agnete Fossbakk
- Department of Biomedicine, Section of Biochemistry and Molecular Biology, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
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McKinney J, Knappskog PM, Haavik J. Different properties of the central and peripheral forms of human tryptophan hydroxylase. J Neurochem 2005; 92:311-20. [PMID: 15663479 DOI: 10.1111/j.1471-4159.2004.02850.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tryptophan hydroxylase (TPH) catalyses the rate-limiting reaction in the biosynthesis of serotonin. In humans, two different TPH genes exist, located on chromosomes 11 and 12, respectively, and encoding two enzymes (TPH1 and TPH2) with an overall sequence identity of 71%. We have expressed both enzymes as various fusion proteins in Escherichia coli and using an in vitro transcription/translation system, and compared their solubility and kinetic properties. TPH2 is more soluble than TPH1, has a higher molecular weight and different kinetic properties, including a lower catalytic efficiency towards phenylalanine than TPH1. Both enzymes are phosphorylated by cAMP-dependent protein kinase A. TPH2 was phosphorylated at Ser19, a phosphorylation site not present in TPH1. The differences between TPH1 and TPH2 have important implications for the regulation of serotonin production in the brain and the periphery and may provide an explanation for some of the diverging results reported for TPH from different sources in the past.
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Affiliation(s)
- Jeffrey McKinney
- Department of Biomedicine, Section of Biochemistry and Molecular Biology, University of Bergen, Bergen, Norway
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Teigen K, Dao KK, McKinney JA, Gorren ACF, Mayer B, Frøystein NA, Haavik J, Martínez A. Tetrahydrobiopterin binding to aromatic amino acid hydroxylases. Ligand recognition and specificity. J Med Chem 2004; 47:5962-71. [PMID: 15537351 DOI: 10.1021/jm0497646] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The three aromatic amino acid hydroxylases (phenylalanine, tyrosine, and tryptophan hydroxylase) and nitric oxide synthase (NOS) all utilize (6R)-l-erythro-5,6,7,8-tetrahydrobiopterin (BH(4)) as cofactor. The pterin binding site in the three hydroxylases is well conserved and different from the binding site in NOS. The structures of phenylalanine hydroxylase (PAH) and of NOS in complex with BH(4) are still the only crystal structures available for the reduced cofactor-enzyme complexes. We have studied the enzyme-bound and free conformations of BH(4) by NMR spectroscopy and molecular docking into the active site of the three hydroxylases, using endothelial NOS as a comparative probe. We have found that the dihydroxypropyl side chain of BH(4) adopts different conformations depending on which hydroxylase it interacts with. All the bound conformations are different from that of BH(4) free in solution at neutral pH. The different bound conformations appear to result from specific interactions with nonconserved amino acids at the BH(4) binding sites of the hydroxylases, notably the stretch 248-251 (numeration in PAH) and the residue corresponding to Ala322 in PAH, i.e., Ser in TH and Ala in TPH. On the basis of analysis of molecular interaction fields, we discuss the selectivity determinants for each hydroxylase and explain the high-affinity inhibitory effect of 7-tetrahydrobiopterin specifically for PAH.
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Affiliation(s)
- Knut Teigen
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009-Bergen, Norway
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McKinney J, Knappskog PM, Pereira J, Ekern T, Toska K, Kuitert BB, Levine D, Gronenborn AM, Martinez A, Haavik J. Expression and purification of human tryptophan hydroxylase from Escherichia coli and Pichia pastoris. Protein Expr Purif 2004; 33:185-94. [PMID: 14711505 DOI: 10.1016/j.pep.2003.09.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tryptophan hydroxylase (TPH) from several mammalian species has previously been cloned and expressed in bacteria. However, due to the instability of wild type TPH, most successful attempts have been limited to the truncated forms of this enzyme. We have expressed full-length human TPH in large amounts in Escherichia coli and Pichia pastoris and purified the enzyme using new purification protocols. When expressed as a fusion protein in E. coli, the maltose-binding protein-TPH (MBP-TPH) fusion protein was more soluble than native TPH and the other fusion proteins and had a 3-fold higher specific activity than the His-Patch-thioredoxin-TPH and 6xHis-TPH fusion proteins. The purified MBP-TPH had a V(max) of 296 nmol/min/mg and a K(m) for L-tryptophan of 7.5+/-0.7 microM, compared to 18+/-5 microM for the partially purified enzyme from P. pastoris. To overcome the unfavorable properties of TPH, the stabilizing effect of different agents was investigated. Both tryptophan and glycerol had a stabilizing effect, whereas dithiothreitol, (6R)-5,6,7,8,-tetrahydrobiopterin, and Fe(2+) inactivated the enzyme. Irrespective of expression conditions, both native TPH expressed in bacteria or yeast, or TPH fusion proteins expressed in bacteria exhibited a strong tendency to aggregate and precipitate during purification, indicating that this is an intrinsic property of this enzyme. This supports previous observations that the enzyme in vivo may be stabilized by additional interactions.
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Affiliation(s)
- Jeffrey McKinney
- Department of Biochemistry and Molecular Biology, University of Bergen, Bergen, Norway.
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Costas M, Mehn MP, Jensen MP, Que L. Dioxygen Activation at Mononuclear Nonheme Iron Active Sites: Enzymes, Models, and Intermediates. Chem Rev 2004; 104:939-86. [PMID: 14871146 DOI: 10.1021/cr020628n] [Citation(s) in RCA: 2007] [Impact Index Per Article: 100.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Miquel Costas
- Departament de Quimica, Universitat de Girona, 17071, Girona, Spain
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Yaguchi S, Katow H. Expression of tryptophan 5-hydroxylase gene during sea urchin neurogenesis and role of serotonergic nervous system in larval behavior. J Comp Neurol 2003; 466:219-29. [PMID: 14528449 DOI: 10.1002/cne.10865] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tryptophan 5-hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of serotonin. cDNA cloning of TPH was carried out, and the occurrence of spatiotemporal transcription of TPH message was examined in larvae of the sea urchin, Hemicentrotus pulcherrimus (HpTPH), with in situ hybridization by using the tyramide signal amplification (TSA) technique and Northern hybridization. Based on deduced amino acids sequence of HpTPH, phylogenetically sea urchin locates at the closest position to vertebrates among invertebrates, and HpTPH had common conserved sequences in a catalytic domain. Initiation of HpTPH transcription occurred at the late gastrula stage exclusively in serotonin cells of apical ganglion (SAG) that was composed of a cluster of HpTPH-positive cells and the negative cells in between. In situ hybridization showed that the mRNA expression pattern was similar to the immunohistochemical localization of serotonin cells reported before (Bisgrove and Burke [1986] Dev. Growth Differ. 28:557-569; Yaguchi et al. [2000] Dev. Growth Differ. 42:479-488). p-Chlorophenylalanine (CPA), an irreversible inhibitor of TPH activity, considerably decreased serotonin content in the serotonin cells, whereas the HpTPH expression pattern and timing, and the extension of neurofibers from SAG cells were apparently unaffected, suggesting CPA exclusively perturbed synthesis of serotonin but not nervous system organization. CPA-treated larvae did not swim, despite the occurrence of ciliary beating in culture chamber, suggesting that proper serotonin synthesis is necessary for normal swimming of the larvae.
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Affiliation(s)
- Shunsuke Yaguchi
- Laboratory of Developmental and Cell Biology, Marine Biological Station, Graduate School of Life Sciences, University of Tohoku, Asamushi, Aomori, Aomori 039-3501, Japan
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50
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA.
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