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Scholtysek L, Poetsch A, Hofmann E, Hemschemeier A. The activation of Chlamydomonas reinhardtii alpha amylase 2 by glutamine requires its N-terminal aspartate kinase-chorismate mutase-tyrA (ACT) domain. PLANT DIRECT 2024; 8:e609. [PMID: 38911017 PMCID: PMC11190351 DOI: 10.1002/pld3.609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/08/2024] [Accepted: 05/16/2024] [Indexed: 06/25/2024]
Abstract
The coordination of assimilation pathways for all the elements that make up cellular components is a vital task for every organism. Integrating the assimilation and use of carbon (C) and nitrogen (N) is of particular importance because of the high cellular abundance of these elements. Starch is one of the most important storage polymers of photosynthetic organisms, and a complex regulatory network ensures that biosynthesis and degradation of starch are coordinated with photosynthetic activity and growth. Here, we analyzed three starch metabolism enzymes of Chlamydomonas reinhardtii that we captured by a cyclic guanosine monophosphate (cGMP) affinity chromatography approach, namely, soluble starch synthase STA3, starch-branching enzyme SBE1, and α-amylase AMA2. While none of the recombinant enzymes was directly affected by the presence of cGMP or other nucleotides, suggesting an indirect binding to cGMP, AMA2 activity was stimulated in the presence of L-glutamine (Gln). This activating effect required the enzyme's N-terminal aspartate kinase-chorismate mutase-tyrA domain. Gln is the first N assimilation product and not only a central compound for the biosynthesis of N-containing molecules but also a recognized signaling molecule for the N status. Our observation suggests that AMA2 might be a means to coordinate N and C metabolism at the enzymatic level, increasing the liberation of C skeletons from starch when high Gln levels signal an abundance of assimilated N.
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Affiliation(s)
- Lisa Scholtysek
- Faculty of Biology and Biotechnology, PhotobiotechnologyRuhr University BochumBochumGermany
| | - Ansgar Poetsch
- Faculty of Biology and Biotechnology, Department for Plant BiochemistryRuhr University BochumBochumGermany
- School of Basic Medical SciencesNanchang UniversityNanchangChina
| | - Eckhard Hofmann
- Faculty of Biology and Biotechnology, Protein CrystallographyRuhr University BochumBochumGermany
| | - Anja Hemschemeier
- Faculty of Biology and Biotechnology, PhotobiotechnologyRuhr University BochumBochumGermany
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2
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Yao JY, Li L, Xu JX, Liu YH, Shi J, Yu XQ, Kong QQ, Li K. Real-Time Monitoring of Tyrosine Hydroxylase Activity with a Ratiometric Fluorescent Probe. Anal Chem 2024; 96:7082-7090. [PMID: 38652135 DOI: 10.1021/acs.analchem.4c00382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Parkinson's disease (PD) represents the second most widespread neurodegenerative disease, and early monitoring and diagnosis are urgent at present. Tyrosine hydroxylase (TH) is a key enzyme for producing dopamine, the levels of which can serve as an indicator for assessing the severity and progression of PD. This renders the specific detection and visualization of TH a strategically vital way to meet the above demands. However, a fluorescent probe for TH monitoring is still missing. Herein, three rationally designed wash-free ratiometric fluorescent probes were proposed. Among them, TH-1 exhibited ideal photophysical properties and specific dual-channel bioimaging of TH activity in SH-SY5Y nerve cells. Moreover, the probe allowed for in vivo imaging of TH activity in zebrafish brain and living striatal slices of mice. Overall, the ratiometric fluorescent probe TH-1 could serve as a potential tool for real-time monitoring of PD in complex biosystems.
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Affiliation(s)
- Jia-Yi Yao
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China
| | - Lu Li
- Orthopedic Department, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Sichuan University, Chengdu, Sichuan 610041, P. R. China
| | - Ji-Xuan Xu
- Orthopedic Department, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Sichuan University, Chengdu, Sichuan 610041, P. R. China
| | - Yan-Hong Liu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China
| | - Jing Shi
- Orthopedic Department, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Sichuan University, Chengdu, Sichuan 610041, P. R. China
| | - Xiao-Qi Yu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China
- Asymmetric Synthesis and Chiral Technology Key Laboratory of Sichuan Province, Department of Chemistry, Xihua University, Chengdu 610039, P. R. China
| | - Qing-Quan Kong
- Orthopedic Department, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Sichuan University, Chengdu, Sichuan 610041, P. R. China
| | - Kun Li
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, P. R. China
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3
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Sobrado P, Neira JL. Paul F. Fitzpatrick: A life of editorial duties and elucidating the mechanism of enzyme action. Arch Biochem Biophys 2023; 742:109635. [PMID: 37209767 DOI: 10.1016/j.abb.2023.109635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 05/22/2023]
Affiliation(s)
- Pablo Sobrado
- Department of Biochemistry, Virginia Tech, 360 West Campus Drive, Blacksburg, VA, 24061, USA.
| | - José Luis Neira
- IDIBE, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos (BIFI) - Unidad Mixta GBsC-CSIC-BIFI, Universidad de Zaragoza, 50018, Zaragoza, Spain.
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Vedel IM, Prestel A, Zhang Z, Skawinska NT, Stark H, Harris P, Kragelund BB, Peters GHJ. Structural characterization of human tryptophan hydroxylase 2 reveals that L-Phe is superior to L-Trp as the regulatory domain ligand. Structure 2023:S0969-2126(23)00127-2. [PMID: 37119821 DOI: 10.1016/j.str.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/03/2023] [Accepted: 04/04/2023] [Indexed: 05/01/2023]
Abstract
Tryptophan hydroxylase 2 (TPH2) catalyzes the rate-limiting step in serotonin biosynthesis in the brain. Consequently, regulation of TPH2 is relevant for serotonin-related diseases, yet the regulatory mechanism of TPH2 is poorly understood and structural and dynamical insights are missing. We use NMR spectroscopy to determine the structure of a 47 N-terminally truncated variant of the regulatory domain (RD) dimer of human TPH2 in complex with L-Phe, and show that L-Phe is the superior RD ligand compared with the natural substrate, L-Trp. Using cryo-EM, we obtain a low-resolution structure of a similarly truncated variant of the complete tetrameric enzyme with dimerized RDs. The cryo-EM two-dimensional (2D) class averages additionally indicate that the RDs are dynamic in the tetramer and likely exist in a monomer-dimer equilibrium. Our results provide structural information on the RD as an isolated domain and in the TPH2 tetramer, which will facilitate future elucidation of TPH2's regulatory mechanism.
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Affiliation(s)
- Ida M Vedel
- Department of Chemistry, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Andreas Prestel
- Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark
| | - Zhenwei Zhang
- Department of Structural Dynamics, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Natalia T Skawinska
- Department of Chemistry, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Holger Stark
- Department of Structural Dynamics, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Pernille Harris
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | - Birthe B Kragelund
- Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark.
| | - Günther H J Peters
- Department of Chemistry, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
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Fitzpatrick PF. The aromatic amino acid hydroxylases: Structures, catalysis, and regulation of phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase. Arch Biochem Biophys 2023; 735:109518. [PMID: 36639008 DOI: 10.1016/j.abb.2023.109518] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/01/2023] [Accepted: 01/06/2023] [Indexed: 01/12/2023]
Abstract
The aromatic amino acid hydroxylases phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase are non-heme iron enzymes that catalyze key physiological reactions. This review discusses the present understanding of the common catalytic mechanism of these enzymes and recent advances in understanding the relationship between their structures and their regulation.
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
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Lehrer S, Rheinstein PH. α-synuclein enfolds tyrosine hydroxylase and dopamine ß-hydroxylase, potentially reducing dopamine and norepinephrine synthesis. JOURNAL OF PROTEINS AND PROTEOMICS 2022; 13:109-115. [PMID: 36277464 PMCID: PMC9585989 DOI: 10.1007/s42485-022-00088-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Parkinson's disease (PD) results from degeneration of dopamine and norepinephrine neurons due to α-synuclein aggregates that likely have their origin in the gut. Tyrosine hydroxylase (TH) catalyses the formation of L-DOPA, the rate-limiting step in the biosynthesis of dopamine. A second enzyme, DOPA decarboxylase (DDC), catalyzes the conversion of L-DOPA to dopamine. A third enzyme, dopamine ß-hydroxylase (DBH), catalyzes the conversion of dopamine to norepinephrine. To analyze possible interactions of α-synuclein with TH, DDC and DBH, we performed in silico protein-protein docking. METHODS Protein data bank (pdb) entries were searched on the RCSB Protein Data Bank. We identified four structures that allowed us to examine the relationship of α-synuclein with TH, DDC, and DBH: (1) Human micelle-bound alpha-synuclein, (2) solution structure of the regulatory domain of tyrosine hydroxylase (Rattus norvegicus), (3) crystal structure of human aromatic L-amino acid decarboxylase (DOPA decarboxylase) in the apo form and (4) crystal structure of human dopamine ß-hydroxylase at 2.9 angstrom resolution. We used the ClusPro server (https://cluspro.org) for protein-protein docking. The protein structures were visualized with PyMOL v 2.3.4. RESULTS α-synuclein partially enfolds tyrosine hydroxylase and dopamine ß-hydroxylase, potentially reducing dopamine and norepinephrine synthesis. α-synuclein may dock too far away from DOPA decarboxylase to affect its function directly. CONCLUSIONS Our in silico finding of α-synuclein partly enfolding tyrosine hydroxylase and dopamine ß-hydroxylase suggests that α-synuclein docking inhibition could increase dopamine and norepinephrine biosynthesis, ameliorating PD symptoms. Small molecules that bind to α-synuclein have already been identified. Further studies may lead to new small molecule drugs that block α-synuclein enfolding of tyrosine hydroxylase and dopamine ß-hydroxylase.
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Affiliation(s)
- Steven Lehrer
- Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, Mount Sinai Medical Center, 1 Gustave L. Levy Place, Box 1236, New York, NY 10029, USA
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Spontaneous changes in brain striatal dopamine synthesis and storage dynamics ex vivo reveal end-product feedback-inhibition of tyrosine hydroxylase. Neuropharmacology 2022; 212:109058. [DOI: 10.1016/j.neuropharm.2022.109058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/09/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022]
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Bueno-Carrasco MT, Cuéllar J, Flydal MI, Santiago C, Kråkenes TA, Kleppe R, López-Blanco JR, Marcilla M, Teigen K, Alvira S, Chacón P, Martinez A, Valpuesta JM. Structural mechanism for tyrosine hydroxylase inhibition by dopamine and reactivation by Ser40 phosphorylation. Nat Commun 2022; 13:74. [PMID: 35013193 PMCID: PMC8748767 DOI: 10.1038/s41467-021-27657-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 12/03/2021] [Indexed: 12/15/2022] Open
Abstract
Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of dopamine (DA) and other catecholamines, and its dysfunction leads to DA deficiency and parkinsonisms. Inhibition by catecholamines and reactivation by S40 phosphorylation are key regulatory mechanisms of TH activity and conformational stability. We used Cryo-EM to determine the structures of full-length human TH without and with DA, and the structure of S40 phosphorylated TH, complemented with biophysical and biochemical characterizations and molecular dynamics simulations. TH presents a tetrameric structure with dimerized regulatory domains that are separated 15 Å from the catalytic domains. Upon DA binding, a 20-residue α-helix in the flexible N-terminal tail of the regulatory domain is fixed in the active site, blocking it, while S40-phosphorylation forces its egress. The structures reveal the molecular basis of the inhibitory and stabilizing effects of DA and its counteraction by S40-phosphorylation, key regulatory mechanisms for homeostasis of DA and TH. Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the synthesis of the catecholamine neurotransmitters and hormones dopamine (DA), adrenaline and noradrenaline. Here, the authors present the cryo-EM structures of full-length human TH in the apo form and bound with DA, as well as the structure of Ser40 phosphorylated TH, and discuss the inhibitory and stabilizing effects of DA on TH and its counteraction by Ser40-phosphorylation.
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Affiliation(s)
| | - Jorge Cuéllar
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
| | - Marte I Flydal
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - César Santiago
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | | | - Rune Kleppe
- Norwegian Centre for Maritime and Diving Medicine, Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway
| | | | | | - Knut Teigen
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Sara Alvira
- Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.,School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Pablo Chacón
- Instituto de Química Física Rocasolano (IQFR-CSIC), Madrid, Spain
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Bergen, Norway.
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Personalized Medicine to Improve Treatment of Dopa-Responsive Dystonia-A Focus on Tyrosine Hydroxylase Deficiency. J Pers Med 2021; 11:jpm11111186. [PMID: 34834538 PMCID: PMC8625014 DOI: 10.3390/jpm11111186] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 11/25/2022] Open
Abstract
Dopa-responsive dystonia (DRD) is a rare movement disorder associated with defective dopamine synthesis. This impairment may be due to the fact of a deficiency in GTP cyclohydrolase I (GTPCHI, GCH1 gene), sepiapterin reductase (SR), tyrosine hydroxylase (TH), or 6-pyruvoyl tetrahydrobiopterin synthase (PTPS) enzyme functions. Mutations in GCH1 are most frequent, whereas fewer cases have been reported for individual SR-, PTP synthase-, and TH deficiencies. Although termed DRD, a subset of patients responds poorly to L-DOPA. As this is regularly observed in severe cases of TH deficiency (THD), there is an urgent demand for more adequate or personalized treatment options. TH is a key enzyme that catalyzes the rate-limiting step in catecholamine biosynthesis, and THD patients often present with complex and variable phenotypes, which results in frequent misdiagnosis and lack of appropriate treatment. In this expert opinion review, we focus on THD pathophysiology and ongoing efforts to develop novel therapeutics for this rare disorder. We also describe how different modeling approaches can be used to improve genotype to phenotype predictions and to develop in silico testing of treatment strategies. We further discuss the current status of mathematical modeling of catecholamine synthesis and how such models can be used together with biochemical data to improve treatment of DRD patients.
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3D architecture and structural flexibility revealed in the subfamily of large glutamate dehydrogenases by a mycobacterial enzyme. Commun Biol 2021; 4:684. [PMID: 34083757 PMCID: PMC8175468 DOI: 10.1038/s42003-021-02222-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 05/14/2021] [Indexed: 11/16/2022] Open
Abstract
Glutamate dehydrogenases (GDHs) are widespread metabolic enzymes that play key roles in nitrogen homeostasis. Large glutamate dehydrogenases composed of 180 kDa subunits (L-GDHs180) contain long N- and C-terminal segments flanking the catalytic core. Despite the relevance of L-GDHs180 in bacterial physiology, the lack of structural data for these enzymes has limited the progress of functional studies. Here we show that the mycobacterial L-GDH180 (mL-GDH180) adopts a quaternary structure that is radically different from that of related low molecular weight enzymes. Intersubunit contacts in mL-GDH180 involve a C-terminal domain that we propose as a new fold and a flexible N-terminal segment comprising ACT-like and PAS-type domains that could act as metabolic sensors for allosteric regulation. These findings uncover unique aspects of the structure-function relationship in the subfamily of L-GDHs. Lázaro et. al. report the first 3D structure of a large glutamate dehydrogenase (L-GDH), the one corresponding to the Mycobacterium smegmatis enzyme composed of 180 kDa subunits (mL-GDH180), obtained by X-ray crystallography and cryo-electron microscopy. This structure reveals that mL-GDH180 assembles as tetramers with the N- and C-terminal domains being involved in inter-subunit contacts and unveils unique features of the subfamily of L-GDHs.
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Lee YS, Herrera-Tequia A, Silwal J, Geiger JH, Grotewold E. A hydrophobic residue stabilizes dimers of regulatory ACT-like domains in plant basic helix-loop-helix transcription factors. J Biol Chem 2021; 296:100708. [PMID: 33901489 PMCID: PMC8202348 DOI: 10.1016/j.jbc.2021.100708] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 11/12/2022] Open
Abstract
About a third of the plant basic helix–loop–helix (bHLH) transcription factors harbor a C-terminal aspartate kinase, chorismate mutase, and TyrA (ACT)-like domain, which was originally identified in the maize R regulator of anthocyanin biosynthesis, where it modulates the ability of the bHLH to dimerize and bind DNA. Characterization of other bHLH ACT-like domains, such as the one in the Arabidopsis R ortholog, GL3, has not definitively confirmed dimerization, raising the question of the overall role of this potential regulatory domain. To learn more, we compared the dimerization of the ACT-like domains of R (RACT) and GL3 (GL3ACT). We show that RACT dimerizes with a dissociation constant around 100 nM, over an order of magnitude stronger than GL3ACT. Structural predictions combined with mutational analyses demonstrated that V568, located in a hydrophobic pocket in RACT, is important: when mutated to the Ser residue present in GL3ACT, dimerization affinity dropped by almost an order of magnitude. The converse S595V mutation in GL3ACT significantly increased the dimerization strength. We cloned and assayed dimerization for all identified maize ACT-like domains and determined that 12 of 42 formed heterodimers in yeast two-hybrid assays, irrespective of whether they harbored V568, which was often replaced by other aliphatic amino acids. Moreover, we determined that the presence of polar residues at that position occurs only in a small subset of anthocyanin regulators. The combined results provide new insights into possibly regulatory mechanisms and suggest that many of the other plant ACT-like domains associate to modulate fundamental cellular processes.
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Affiliation(s)
- Yun Sun Lee
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Andres Herrera-Tequia
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Jagannath Silwal
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - James H Geiger
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - Erich Grotewold
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, USA.
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Bezem MT, Johannessen FG, Kråkenes TA, Sailor MJ, Martinez A. Relevance of Electrostatics for the Interaction of Tyrosine Hydroxylase with Porous Silicon Nanoparticles. Mol Pharm 2021; 18:976-985. [PMID: 33417459 PMCID: PMC7927144 DOI: 10.1021/acs.molpharmaceut.0c00960] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Tyrosine hydroxylase (TH) is the
enzyme catalyzing the rate-limiting
step in the synthesis of dopamine in the brain. Developing enzyme
replacement therapies using TH could therefore be beneficial to patient
groups with dopamine deficiency, and the use of nanocarriers that
cross the blood–brain barrier seems advantageous for this purpose.
Nanocarriers may also help to maintain the structure and function
of TH, which is complex and unstable. Understanding how TH may interact
with a nanocarrier is therefore crucial for the investigation of such
therapeutic applications. This work describes the interaction of TH
with porous silicon nanoparticles (pSiNPs), chosen since they have
been shown to deliver other macromolecular therapeutics successfully
to the brain. Size distributions obtained by dynamic light scattering
show a size increase of pSiNPs upon addition of TH and the changes
observed at the surface of pSiNPs by transmission electron microscopy
also indicated TH binding at pH 7. As pSiNPs are negatively charged,
we also investigated the binding at pH 6, which makes TH less negatively
charged than at pH 7. However, as seen by thioflavin-T fluorescence,
TH aggregated at this more acidic pH. TH activity was unaffected by
the binding to pSiNPs most probably because the active site stays
available for catalysis, in agreement with calculations of the surface
electrostatic potential pointing to the most positively charged regulatory
domains in the tetramer as the interacting regions. These results
reveal pSiNPs as a promising delivery device of enzymatically active
TH to increase local dopamine synthesis.
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Affiliation(s)
- Maria T Bezem
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, Bergen 5009, Norway
| | - Fredrik G Johannessen
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, Bergen 5009, Norway
| | - Trond-André Kråkenes
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, Bergen 5009, Norway
| | - Michael J Sailor
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, Bergen 5009, Norway
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Liu X, Lv M, Wang Y, Zhao D, Zhao S, Li S, Qin X. Deciphering the compatibility rules of traditional Chinese medicine prescriptions based on NMR metabolomics: A case study of Xiaoyaosan. JOURNAL OF ETHNOPHARMACOLOGY 2020; 254:112726. [PMID: 32135241 DOI: 10.1016/j.jep.2020.112726] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/23/2020] [Accepted: 02/28/2020] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Xiaoyaosan (XYS), a represent and classic TCM prescription, consists of Radix Bupleuri, Radix Angelicae Sinensis, Radix Paeoniae Alba, Rhizoma Atractylodis Macrocephalae, Poria, Herba Menthae, Rhizoma Zingiberis Recens and Radix Glycyrrhizae. XYS can sooth the liver and strengthen the spleen through improving the circulation of qi and nourishing blood according to the TCM theory, therefore exhibiting anti-depression effects. AIM OF THE STUDY This study was conducted to investigate the compatibility rule of antidepressant effect of XYS by using both the "Efficacy Compositions" research strategy and fecal metabolomics approach. MATERIALS AND METHODS XYS was divided into two efficacy groups, i.e. the Shugan (SG) and the Jianpi (JP) groups, according to the efficacies of both XYS and the eight herbs recorded in the TCM theory and the research strategy of "Efficacy Compositions". A CUMS-induced depression model was constructed, where rats were randomly divided into 5 groups: negative control (NC), CUMS model (MS), XYS, SG, and JP. Multivariate data analysis including Principal Components Analysis (PCA) and Orthogonal Partial Least Squares-Discriminate Analysis (OPLS-DA) was utilized. Efficacy Index (EI) was calculated. RESULTS Metabolic profiling by PCA showed that XYS exhibited the strongest effect than the two efficacy groups, locating closest to the control group. OPLS-DA showed 10 metabolites were identified as potential biomarkers for the CUMS-induced depression. 8 potential biomarkers were significantly reversed by XYS while 5 and 4 biomarkers were reversed by SG and JP, respectively. The results of regulatory degrees showed that XYS had the highest EI than SG and JP. Concerning metabolic pathways, XYS regulated all the seven metabolic pathways associated with CUMS-induced depression, while SG and JP groups regulated six and three pathways, respectively. CONCLUSIONS The antidepressant effect of XYS was stronger than that of SG and JP. The combined effects of SG and JP brought the integrated antidepressant effect of XYS. This study suggests that a combination of "Efficacy Compositions" strategy and metabolomics approach has great potentials in comprehensively and deeply understanding the scientific connotation of the compatibility rule of TCM prescriptions.
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Affiliation(s)
- Xiaojie Liu
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan, 030006, China; Key Laboratory of Effective Substances Research and Utilization in Traditional Chinese Medicine of Shanxi Province, Shanxi University, Taiyuan, 030006, China.
| | - Meng Lv
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan, 030006, China; Key Laboratory of Effective Substances Research and Utilization in Traditional Chinese Medicine of Shanxi Province, Shanxi University, Taiyuan, 030006, China.
| | - Yaze Wang
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan, 030006, China; Key Laboratory of Effective Substances Research and Utilization in Traditional Chinese Medicine of Shanxi Province, Shanxi University, Taiyuan, 030006, China.
| | - Di Zhao
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan, 030006, China; Key Laboratory of Effective Substances Research and Utilization in Traditional Chinese Medicine of Shanxi Province, Shanxi University, Taiyuan, 030006, China.
| | - Sijun Zhao
- Shanxi Institute for Food and Drug Control, Taiyuan, 030001, China.
| | - Shunyong Li
- School of Mathematics Sciences, Shanxi University, Taiyuan, 030006, China.
| | - Xuemei Qin
- Modern Research Center for Traditional Chinese Medicine, Shanxi University, Taiyuan, 030006, China; Key Laboratory of Effective Substances Research and Utilization in Traditional Chinese Medicine of Shanxi Province, Shanxi University, Taiyuan, 030006, China.
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Toxicity, gut microbiota and metabolome effects after copper exposure during early life in SD rats. Toxicology 2020; 433-434:152395. [PMID: 32027963 DOI: 10.1016/j.tox.2020.152395] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/20/2020] [Accepted: 02/02/2020] [Indexed: 12/27/2022]
Abstract
Copper, an essential microelement, can still be harmful to health and has a significant impact on the gut microbiota, which is closely related to health when copper is ingested excessively. However, the effects of low dose exposure to copper early in life on health and the gut microbiota are not well understood. Here, the effects of early-life exposure of copper on the toxicity, gut microbiota and the metabolome were investigated in Sprague-Dawley (SD) rats. The results showed that 0.20 and 1.00 mg/kg BW copper early-life exposure in SD rats significantly increased ALT, AST, and ALP levels in the blood and caused liver damage. Copper exposure had a dose-dependent effect on the alpha and beta diversity and reduced the abundance of probiotics, the ratio of Firmicutes to Bacteroidetes (F/B), and changed the abundance of fat metabolism and intestinal inflammation-related bacteria. The results of the fecal metabolome also demonstrated the effects of early-life copper exposure on liver damage and intestinal inflammation-related metabolic pathways. Together, our findings demonstrated that copper exposure during early life induced liver damage and gut microbiota dysbiosis and affected the relevant metabolic pathways.
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15
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Tomé CS, Lopes RR, Sousa PMF, Amaro MP, Leandro J, Mertens HDT, Leandro P, Vicente JB. Structure of full-length wild-type human phenylalanine hydroxylase by small angle X-ray scattering reveals substrate-induced conformational stability. Sci Rep 2019; 9:13615. [PMID: 31541188 PMCID: PMC6754429 DOI: 10.1038/s41598-019-49944-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/03/2019] [Indexed: 01/30/2023] Open
Abstract
Human phenylalanine hydroxylase (hPAH) hydroxylates L-phenylalanine (L-Phe) to L-tyrosine, a precursor for neurotransmitter biosynthesis. Phenylketonuria (PKU), caused by mutations in PAH that impair PAH function, leads to neurological impairment when untreated. Understanding the hPAH structural and regulatory properties is essential to outline PKU pathophysiological mechanisms. Each hPAH monomer comprises an N-terminal regulatory, a central catalytic and a C-terminal oligomerisation domain. To maintain physiological L-Phe levels, hPAH employs complex regulatory mechanisms. Resting PAH adopts an auto-inhibited conformation where regulatory domains block access to the active site. L-Phe-mediated allosteric activation induces a repositioning of the regulatory domains. Since a structure of activated wild-type hPAH is lacking, we addressed hPAH L-Phe-mediated conformational changes and report the first solution structure of the allosterically activated state. Our solution structures obtained by small-angle X-ray scattering support a tetramer with distorted P222 symmetry, where catalytic and oligomerisation domains form a core from which regulatory domains protrude, positioning themselves close to the active site entrance in the absence of L-Phe. Binding of L-Phe induces a large movement and dimerisation of regulatory domains, exposing the active site. Activated hPAH is more resistant to proteolytic cleavage and thermal denaturation, suggesting that the association of regulatory domains stabilises hPAH.
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Affiliation(s)
- Catarina S Tomé
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Raquel R Lopes
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro M F Sousa
- Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
| | - Mariana P Amaro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - João Leandro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
- Department of Genetics and Genomic Sciences and Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Paula Leandro
- Research Institute for Medicines (iMed.ULisboa) and Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.
| | - João B Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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16
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Arturo EC, Gupta K, Hansen MR, Borne E, Jaffe EK. Biophysical characterization of full-length human phenylalanine hydroxylase provides a deeper understanding of its quaternary structure equilibrium. J Biol Chem 2019; 294:10131-10145. [PMID: 31076506 PMCID: PMC6664189 DOI: 10.1074/jbc.ra119.008294] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 05/09/2019] [Indexed: 11/06/2022] Open
Abstract
Dysfunction of human phenylalanine hydroxylase (hPAH, EC 1.14.16.1) is the primary cause of phenylketonuria, the most common inborn error of amino acid metabolism. The dynamic domain rearrangements of this multimeric protein have thwarted structural study of the full-length form for decades, until now. In this study, a tractable C29S variant of hPAH (C29S) yielded a 3.06 Å resolution crystal structure of the tetrameric resting-state conformation. We used size-exclusion chromatography in line with small-angle X-ray scattering (SEC-SAXS) to analyze the full-length hPAH solution structure both in the presence and absence of Phe, which serves as both substrate and allosteric activators. Allosteric Phe binding favors accumulation of an activated PAH tetramer conformation, which is biophysically distinct in solution. Protein characterization with enzyme kinetics and intrinsic fluorescence revealed that the C29S variant and hPAH are otherwise equivalent in their response to Phe, further supported by their behavior on various chromatography resins and by analytical ultracentrifugation. Modeling of resting-state and activated forms of C29S against SAXS data with available structural data created and evaluated several new models for the transition between the architecturally distinct conformations of PAH and highlighted unique intra- and inter-subunit interactions. Three best-fitting alternative models all placed the allosteric Phe-binding module 8-10 Å farther from the tetramer center than do all previous models. The structural insights into allosteric activation of hPAH reported here may help inform ongoing efforts to treat phenylketonuria with novel therapeutic approaches.
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Affiliation(s)
- Emilia C Arturo
- From the Molecular Therapeutics Program, Fox Chase Cancer Center, Temple University Health Systems, Philadelphia, Pennsylvania 19111
- the Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, and
| | - Kushol Gupta
- the Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Michael R Hansen
- From the Molecular Therapeutics Program, Fox Chase Cancer Center, Temple University Health Systems, Philadelphia, Pennsylvania 19111
| | - Elias Borne
- From the Molecular Therapeutics Program, Fox Chase Cancer Center, Temple University Health Systems, Philadelphia, Pennsylvania 19111
| | - Eileen K Jaffe
- From the Molecular Therapeutics Program, Fox Chase Cancer Center, Temple University Health Systems, Philadelphia, Pennsylvania 19111,
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17
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Bansal A, Karanth NM, Demeler B, Schindelin H, Sarma SP. Crystallographic Structures of IlvN·Val/Ile Complexes: Conformational Selectivity for Feedback Inhibition of Aceto Hydroxy Acid Synthases. Biochemistry 2019; 58:1992-2008. [PMID: 30887800 PMCID: PMC6668035 DOI: 10.1021/acs.biochem.9b00050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Conformational factors that predicate selectivity for valine or isoleucine binding to IlvN leading to the regulation of aceto hydroxy acid synthase I (AHAS I) of Escherichia coli have been determined for the first time from high-resolution (1.9-2.43 Å) crystal structures of IlvN·Val and IlvN·Ile complexes. The valine and isoleucine ligand binding pockets are located at the dimer interface. In the IlvN·Ile complex, among residues in the binding pocket, the side chain of Cys43 is 2-fold disordered (χ1 angles of gauche- and trans). Only one conformation can be observed for the identical residue in the IlvN·Val complexes. In a reversal, the side chain of His53, located at the surface of the protein, exhibits two conformations in the IlvN·Val complex. The concerted conformational switch in the side chains of Cys43 and His53 may play an important role in the regulation of the AHAS I holoenzyme activity. A significant result is the establishment of the subunit composition in the AHAS I holoenzyme by analytical ultracentrifugation. Solution nuclear magnetic resonance and analytical ultracentrifugation experiments have also provided important insights into the hydrodynamic properties of IlvN in the ligand-free and -bound states. The structural and biophysical data unequivocally establish the molecular basis for differential binding of the ligands to IlvN and a rationale for the resistance of IlvM to feedback inhibition by the branched-chain amino acids.
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Affiliation(s)
- Akanksha Bansal
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - N. Megha Karanth
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Borries Demeler
- Department of Biochemistry and Structural Biology, The University of Texas Health Science Center at San Antonio, Mailcode 7760, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, United States
| | - Hermann Schindelin
- Rudolf Virchow Centre for Experimental Biomedicine, Institute of Structural Biology, University of Wuerzburg, Josef-Schneider-Strasse 2, D-97080 Wuerzburg, Germany
| | - Siddhartha P. Sarma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
- NMR Research Center, Indian Institute of Science, Bangalore, Karnataka 560012, India
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18
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Szigetvari PD, Muruganandam G, Kallio JP, Hallin EI, Fossbakk A, Loris R, Kursula I, Møller LB, Knappskog PM, Kursula P, Haavik J. The quaternary structure of human tyrosine hydroxylase: effects of dystonia-associated missense variants on oligomeric state and enzyme activity. J Neurochem 2018; 148:291-306. [PMID: 30411798 PMCID: PMC6587854 DOI: 10.1111/jnc.14624] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/26/2018] [Accepted: 10/31/2018] [Indexed: 01/27/2023]
Abstract
Abstract Tyrosine hydroxylase (TH) is a multi‐domain, homo‐oligomeric enzyme that catalyses the rate‐limiting step of catecholamine neurotransmitter biosynthesis. Missense variants of human TH are associated with a recessive neurometabolic disease with low levels of brain dopamine and noradrenaline, resulting in a variable clinical picture, from progressive brain encephalopathy to adolescent onset DOPA‐responsive dystonia (DRD). We expressed isoform 1 of human TH (hTH1) and its dystonia‐associated missense variants in E. coli, analysed their quaternary structure and thermal stability using size‐exclusion chromatography, circular dichroism, multi‐angle light scattering, transmission electron microscopy, small‐angle X‐ray scattering and assayed hydroxylase activity. Wild‐type (WT) hTH1 was a mixture of enzymatically stable tetramers (85.6%) and octamers (14.4%), with little interconversion between these species. We also observed small amounts of higher order assemblies of long chains of enzyme by transmission electron microscopy. To investigate the role of molecular assemblies in the pathogenesis of DRD, we compared the structure of WT hTH1 with the DRD‐associated variants R410P and D467G that are found in vicinity of the predicted subunit interfaces. In contrast to WT hTH1, R410P and D467G were mixtures of tetrameric and dimeric species. Inspection of the available structures revealed that Arg‐410 and Asp‐467 are important for maintaining the stability and oligomeric structure of TH. Disruption of the normal quaternary enzyme structure by missense variants is a new molecular mechanism that may explain the loss of TH enzymatic activity in DRD. Unstable missense variants could be targets for pharmacological intervention in DRD, aimed to re‐establish the normal oligomeric state of TH. ![]()
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Affiliation(s)
- Peter D Szigetvari
- Department of Biomedicine, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway
| | - Gopinath Muruganandam
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Juha P Kallio
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Erik I Hallin
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Agnete Fossbakk
- K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway
| | - Remy Loris
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Inari Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Lisbeth B Møller
- Applied Human Molecular Genetics, Kennedy Center, Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
| | - Per M Knappskog
- K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway.,Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Jan Haavik
- Department of Biomedicine, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.,Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
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19
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Human tyrosine hydroxylase in Parkinson's disease and in related disorders. J Neural Transm (Vienna) 2018; 126:397-409. [PMID: 29995172 DOI: 10.1007/s00702-018-1903-3] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 07/05/2018] [Indexed: 10/28/2022]
Abstract
Parkinson's disease (PD) is an aging-related movement disorder mainly caused by a deficiency of neurotransmitter dopamine (DA) in the striatum of the brain and is considered to be due to progressive degeneration of nigro-striatal DA neurons. Most PD is sporadic without family history (sPD), and there are only a few percent of cases of young-onset familial PD (fPD, PARKs) with the chromosomal locations and the genes identified. Tyrosine hydroxylase (TH), tetrahydrobiopterin (BH4)-dependent and iron-containing monooxygenase, catalyzes the conversion of L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA), which is the initial and rate-limiting step in the biosynthesis of catecholamines (DA, noradrenaline, and adrenaline). PD affects specifically TH-containing catecholamine neurons. The most marked neurodegeneration in patients with DA deficiency is observed in the nigro-striatal DA neurons, which contain abundant TH. Accordingly, TH has been speculated to play some important roles in the pathophysiology in PD. However, this decrease in TH is thought to be secondary due to neurodegeneration of DA neurons caused by some as yet unidentified genetic and environmental factors, and thus, TH deficiency may not play a direct role in PD. This manuscript provides an overview of the role of human TH in the pathophysiology of PD, covering the following aspects: (1) structures of the gene and protein of human TH in relation to PD; (2) similarity and dissimilarity between the phenotypes of aging-related sPD and those of young-onset fPD or DOPA-responsive dystonia due to DA deficiency in the striatum with decreased TH activity caused by mutations in either the TH gene or GTP cyclohydrolase I (GCH1) gene; and (3) genetic variants of the TH gene (polymorphisms, rare variants, and mutations) in PD, as discovered recently by advanced genome analysis.
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20
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Zhou YZ, Yan ML, Gao L, Zhang JQ, Qin XM, Zhang X, Du GH. Metabonomics approach to assessing the metabolism variation and gender gap of Drosophila melanogaster in aging process. Exp Gerontol 2017; 98:110-119. [DOI: 10.1016/j.exger.2017.07.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 07/25/2017] [Accepted: 07/31/2017] [Indexed: 02/06/2023]
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21
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Louša P, Nedozrálová H, Župa E, Nováček J, Hritz J. Phosphorylation of the regulatory domain of human tyrosine hydroxylase 1 monitored using non-uniformly sampled NMR. Biophys Chem 2017; 223:25-29. [PMID: 28282625 DOI: 10.1016/j.bpc.2017.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 01/24/2017] [Indexed: 10/20/2022]
Abstract
Human tyrosine hydroxylase 1 (hTH1) activity is regulated by phosphorylation of its regulatory domain (RD-hTH1) and by an interaction with the 14-3-3 protein. The RD-hTH1 is composed of a structured region (66-169) preceded by an intrinsically disordered protein region (IDP, hTH1_65) containing two phosphorylation sites (S19 and S40) which are highly relevant for its increase in activity. The NMR signals of the IDP region in the non-phosphorylated, singly phosphorylated (pS40) and doubly phosphorylated states (pS19_pS40) were assigned by non-uniformly sampled spectra with increased dimensionality (5D). The structural changes induced by phosphorylation were analyzed by means of secondary structure propensities. The phosphorylation kinetics of the S40 and S19 by kinases PKA and PRAK respectively were monitored by non-uniformly sampled time-resolved NMR spectroscopy followed by their quantitative analysis.
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Affiliation(s)
- Petr Louša
- CEITEC MU, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Hana Nedozrálová
- CEITEC MU, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Erik Župa
- CEITEC MU, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Jiří Nováček
- CEITEC MU, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Jozef Hritz
- CEITEC MU, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic.
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22
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Waløen K, Kleppe R, Martinez A, Haavik J. Tyrosine and tryptophan hydroxylases as therapeutic targets in human disease. Expert Opin Ther Targets 2016; 21:167-180. [PMID: 27973928 DOI: 10.1080/14728222.2017.1272581] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The ancient and ubiquitous monoamine signalling molecules serotonin, dopamine, norepinephrine, and epinephrine are involved in multiple physiological functions. The aromatic amino acid hydroxylases tyrosine hydroxylase (TH), tryptophan hydroxylase 1 (TPH1), and tryptophan hydroxylase 2 (TPH2) catalyse the rate-limiting steps in the biosynthesis of these monoamines. Genetic variants of TH, TPH1, and TPH2 genes are associated with neuropsychiatric disorders. The interest in these enzymes as therapeutic targets is increasing as new roles of these monoamines have been discovered, not only in brain function and disease, but also in development, cardiovascular function, energy and bone homeostasis, gastrointestinal motility, hemostasis, and liver function. Areas covered: Physiological roles of TH, TPH1, and TPH2. Enzyme structures, catalytic and regulatory mechanisms, animal models, and associated diseases. Interactions with inhibitors, pharmacological chaperones, and regulatory proteins relevant for drug development. Expert opinion: Established inhibitors of these enzymes mainly target their amino acid substrate binding site, while tetrahydrobiopterin analogues, iron chelators, and allosteric ligands are less studied. New insights into monoamine biology and 3D-structural information and new computational/experimental tools have triggered the development of a new generation of more selective inhibitors and pharmacological chaperones. The enzyme complexes with their regulatory 14-3-3 proteins are also emerging as therapeutic targets.
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Affiliation(s)
- Kai Waløen
- a Department of Biomedicine and K.G. Jebsen Centre for Neuropsychiatric Disorders , University of Bergen , Bergen , Norway
| | - Rune Kleppe
- b Computational Biology Unit, Department of Informatics , University of Bergen , Bergen , Norway
| | - Aurora Martinez
- a Department of Biomedicine and K.G. Jebsen Centre for Neuropsychiatric Disorders , University of Bergen , Bergen , Norway
| | - Jan Haavik
- a Department of Biomedicine and K.G. Jebsen Centre for Neuropsychiatric Disorders , University of Bergen , Bergen , Norway
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23
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Baumann A, Jorge-Finnigan A, Jung-Kc K, Sauter A, Horvath I, Morozova-Roche LA, Martinez A. Tyrosine Hydroxylase Binding to Phospholipid Membranes Prompts Its Amyloid Aggregation and Compromises Bilayer Integrity. Sci Rep 2016; 6:39488. [PMID: 28004763 PMCID: PMC5177901 DOI: 10.1038/srep39488] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 11/21/2016] [Indexed: 12/14/2022] Open
Abstract
Tyrosine hydroxylase (TH), a rate-limiting enzyme in the synthesis of catecholamine neurotransmitters and hormones, binds to negatively charged phospholipid membranes. Binding to both large and giant unilamellar vesicles causes membrane permeabilization, as observed by efflux and influx of fluorescence dyes. Whereas the initial protein-membrane interaction involves the N-terminal tail that constitutes an extension of the regulatory ACT-domain, prolonged membrane binding induces misfolding and self-oligomerization of TH over time as shown by circular dichroism and Thioflavin T fluorescence. The gradual amyloid-like aggregation likely occurs through cross-β interactions involving aggregation-prone motives in the catalytic domains, consistent with the formation of chain and ring-like protofilaments observed by atomic force microscopy in monolayer-bound TH. PC12 cells treated with the neurotoxin 6-hydroxydopamine displayed increased TH levels in the mitochondrial fraction, while incubation of isolated mitochondria with TH led to a decrease in the mitochondrial membrane potential. Furthermore, cell-substrate impedance and viability assays showed that supplementing the culture media with TH compromises cell viability over time. Our results revealed that the disruptive effect of TH on cell membranes may be a cytotoxic and pathogenic factor if the regulation and intracellular stability of TH is compromised.
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Affiliation(s)
- Anne Baumann
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway.,Division of Psychiatry, Haukeland University Hospital, 5021 Bergen, Norway
| | - Ana Jorge-Finnigan
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway.,K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5009 Bergen, Norway
| | - Kunwar Jung-Kc
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway
| | - Alexander Sauter
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway.,Department of Clinical Dentistry, University of Bergen, 5009 Bergen, Norway
| | - Istvan Horvath
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187 Umeå, Sweden
| | | | - Aurora Martinez
- Department of Biomedicine, University of Bergen, 5009 Bergen, Norway.,K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5009 Bergen, Norway
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24
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Proteasome-mediated degradation of tyrosine hydroxylase triggered by its phosphorylation: a new question as to the intracellular location at which the degradation occurs. J Neural Transm (Vienna) 2016; 125:9-15. [DOI: 10.1007/s00702-016-1653-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/14/2016] [Indexed: 10/20/2022]
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25
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Tidemand KD, Christensen HEM, Hoeck N, Harris P, Boesen J, Peters GH. Stabilization of tryptophan hydroxylase 2 by l-phenylalanine-induced dimerization. FEBS Open Bio 2016; 6:987-999. [PMID: 27761358 PMCID: PMC5055035 DOI: 10.1002/2211-5463.12100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 06/20/2016] [Accepted: 06/29/2016] [Indexed: 12/12/2022] Open
Abstract
Tryptophan hydroxylase 2 (TPH2) catalyses the initial and rate‐limiting step in the biosynthesis of serotonin, which is associated with a variety of disorders such as depression, obsessive compulsive disorder, and schizophrenia. Full‐length TPH2 is poorly characterized due to low purification quantities caused by its inherent instability. Three truncated variants of human TPH2 (rchTPH2; regulatory and catalytic domain, NΔ47‐rchTPH2; truncation of 47 residues in the N terminus of rchTPH2, and chTPH2; catalytic domain) were expressed, purified, and examined for changes in transition temperature, inactivation rate, and oligomeric state. chTPH2 displayed 14‐ and 11‐fold higher half‐lives compared to rchTPH2 and NΔ47‐rchTPH2, respectively. Differential scanning calorimetry experiments demonstrated that this is caused by premature unfolding of the less stable regulatory domain. By differential scanning fluorimetry, the unfolding transitions of rchTPH2 and NΔ47‐rchTPH2 are found to shift from polyphasic to apparent two‐state by the addition of l‐Trp or l‐Phe. Analytical gel filtration revealed that rchTPH2 and NΔ47‐rchTPH2 reside in a monomer–dimer equilibrium which is significantly shifted toward dimer in the presence of l‐Phe. The dimerizing effect induced by l‐Phe is accompanied by a stabilizing effect, which resulted in a threefold increase in half‐lives of rchTPH2 and NΔ47‐rchTPH2. Addition of l‐Phe to the purification buffer significantly increases the purification yields, which will facilitate characterization of hTPH2.
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Affiliation(s)
- Kasper D Tidemand
- Department of Chemistry Technical University of Denmark Kongens Lyngby Denmark
| | | | - Niclas Hoeck
- Department of Chemistry Technical University of Denmark Kongens Lyngby Denmark
| | - Pernille Harris
- Department of Chemistry Technical University of Denmark Kongens Lyngby Denmark
| | - Jane Boesen
- Department of Chemistry Technical University of Denmark Kongens Lyngby Denmark
| | - Günther H Peters
- Department of Chemistry Technical University of Denmark Kongens Lyngby Denmark
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26
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Stable preparations of tyrosine hydroxylase provide the solution structure of the full-length enzyme. Sci Rep 2016; 6:30390. [PMID: 27462005 PMCID: PMC4961952 DOI: 10.1038/srep30390] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/30/2016] [Indexed: 01/22/2023] Open
Abstract
Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of catecholamine neurotransmitters. TH is a highly complex enzyme at mechanistic, structural, and regulatory levels, and the preparation of kinetically and conformationally stable enzyme for structural characterization has been challenging. Here, we report on improved protocols for purification of recombinant human TH isoform 1 (TH1), which provide large amounts of pure, stable, active TH1 with an intact N-terminus. TH1 purified through fusion with a His-tagged maltose-binding protein on amylose resin was representative of the iron-bound functional enzyme, showing high activity and stabilization by the natural feedback inhibitor dopamine. TH1 purified through fusion with a His-tagged ZZ domain on TALON is remarkably stable, as it was partially inhibited by resin-derived cobalt. This more stable enzyme preparation provided high-quality small-angle X-ray scattering (SAXS) data and reliable structural models of full-length tetrameric TH1. The SAXS-derived model reveals an elongated conformation (Dmax = 20 nm) for TH1, different arrangement of the catalytic domains compared with the crystal structure of truncated forms, and an N-terminal region with an unstructured tail that hosts the phosphorylation sites and a separated Ala-rich helical motif that may have a role in regulation of TH by interacting with binding partners.
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27
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Neira JL, Hornos F, Bacarizo J, Cámara-Artigás A, Gómez J. The Monomeric Species of the Regulatory Domain of Tyrosine Hydroxylase Has a Low Conformational Stability. Biochemistry 2016; 55:3418-31. [PMID: 27224548 DOI: 10.1021/acs.biochem.6b00135] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tyrosine hydroxylase (TyrH) catalyzes the hydroxylation of tyrosine to form 3,4-dihydroxyphenylalanine, the first step in the synthesis of catecholamine neurotransmitters. The protein contains a 159-residue regulatory domain (RD) at its N-terminus that forms dimers in solution; the N-terminal region of RDTyrH (residues 1-71) is absent in the solution structure of the domain. We have characterized the conformational stability of two species of RDTyrH (one containing the N-terminal region and another lacking the first 64 residues) to clarify how that N-terminal region modulates the conformational stability of RD. Under the conditions used in this study, the RD species lacking the first 64 residues is a monomer at pH 7.0, with a small conformational stability at 25 °C (4.7 ± 0.8 kcal mol(-1)). On the other hand, the entire RDTyrH is dimeric at physiological pH, with an estimated dissociation constant of 1.6 μM, as determined by zonal gel filtration chromatography; dimer dissociation was spectroscopically silent to circular dichroism but not to fluoresecence. Both RD species were disordered below physiological pH, but the acquisition of secondary native-like structure occurs at pHs lower than those measured for the attainment of tertiary native- and compactness-like arrangements.
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Affiliation(s)
- José L Neira
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández , 03202 Elche (Alicante), Spain.,Biocomputation and Complex Systems Physics Institute , 50009 Zaragoza, Spain
| | - Felipe Hornos
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández , 03202 Elche (Alicante), Spain
| | - Julio Bacarizo
- Department of Physical Chemistry, Biochemistry and Inorganic Chemistry, University of Almería , Agrifood Campus of International Excellence (ceiA3), Almería, Spain
| | - Ana Cámara-Artigás
- Department of Physical Chemistry, Biochemistry and Inorganic Chemistry, University of Almería , Agrifood Campus of International Excellence (ceiA3), Almería, Spain
| | - Javier Gómez
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández , 03202 Elche (Alicante), Spain
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28
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The regulatory domain of human tryptophan hydroxylase 1 forms a stable dimer. Biochem Biophys Res Commun 2016; 476:457-461. [PMID: 27255998 DOI: 10.1016/j.bbrc.2016.05.144] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 05/27/2016] [Indexed: 02/06/2023]
Abstract
The three eukaryotic aromatic amino acid hydroxylases phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase have essentially identical catalytic domains and discrete regulatory domains. The regulatory domains of phenylalanine hydroxylase form ACT domain dimers when phenylalanine is bound to an allosteric site. In contrast the regulatory domains of tyrosine hydroxylase form a stable ACT dimer that does not bind the amino acid substrate. The regulatory domain of isoform 1 of human tryptophan hydroxylase was expressed and purified; mutagenesis of Cys64 was required to prevent formation of disulfide-linked dimers. The resulting protein behaved as a dimer upon gel filtration and in analytical ultracentrifugation. The sw value of the protein was unchanged from 2.7 to 35 μM, a concentration range over which the regulatory domain of phenylalanine hydroxylase forms both monomers and dimers, consistent with the regulatory domain of tryptophan hydroxylase 1 forming a stable dimer stable that does not undergo a monomer-dimer equilibrium. Addition of phenylalanine, a good substrate for the enzyme, had no effect on the sw value, consistent with there being no allosteric site for the amino acid substrate.
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29
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Meisburger SP, Taylor AB, Khan CA, Zhang S, Fitzpatrick PF, Ando N. Domain Movements upon Activation of Phenylalanine Hydroxylase Characterized by Crystallography and Chromatography-Coupled Small-Angle X-ray Scattering. J Am Chem Soc 2016; 138:6506-16. [PMID: 27145334 PMCID: PMC4896396 DOI: 10.1021/jacs.6b01563] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mammalian phenylalanine hydroxylase (PheH) is an allosteric enzyme that catalyzes the first step in the catabolism of the amino acid phenylalanine. Following allosteric activation by high phenylalanine levels, the enzyme catalyzes the pterin-dependent conversion of phenylalanine to tyrosine. Inability to control elevated phenylalanine levels in the blood leads to increased risk of mental disabilities commonly associated with the inherited metabolic disorder, phenylketonuria. Although extensively studied, structural changes associated with allosteric activation in mammalian PheH have been elusive. Here, we examine the complex allosteric mechanisms of rat PheH using X-ray crystallography, isothermal titration calorimetry (ITC), and small-angle X-ray scattering (SAXS). We describe crystal structures of the preactivated state of the PheH tetramer depicting the regulatory domains docked against the catalytic domains and preventing substrate binding. Using SAXS, we further describe the domain movements involved in allosteric activation of PheH in solution and present the first demonstration of chromatography-coupled SAXS with Evolving Factor Analysis (EFA), a powerful method for separating scattering components in a model-independent way. Together, these results support a model for allostery in PheH in which phenylalanine stabilizes the dimerization of the regulatory domains and exposes the active site for substrate binding and other structural changes needed for activity.
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Affiliation(s)
- Steve P. Meisburger
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
| | - Alexander B. Taylor
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Crystal A. Khan
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Shengnan Zhang
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Paul F. Fitzpatrick
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Nozomi Ando
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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30
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Boulton S, Melacini G. Advances in NMR Methods To Map Allosteric Sites: From Models to Translation. Chem Rev 2016; 116:6267-304. [PMID: 27111288 DOI: 10.1021/acs.chemrev.5b00718] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The last five years have witnessed major developments in the understanding of the allosteric phenomenon, broadly defined as coupling between remote molecular sites. Such advances have been driven not only by new theoretical models and pharmacological applications of allostery, but also by progress in the experimental approaches designed to map allosteric sites and transitions. Among these techniques, NMR spectroscopy has played a major role given its unique near-atomic resolution and sensitivity to the dynamics that underlie allosteric couplings. Here, we highlight recent progress in the NMR methods tailored to investigate allostery with the goal of offering an overview of which NMR approaches are best suited for which allosterically relevant questions. The picture of the allosteric "NMR toolbox" is provided starting from one of the simplest models of allostery (i.e., the four-state thermodynamic cycle) and continuing to more complex multistate mechanisms. We also review how such an "NMR toolbox" has assisted the elucidation of the allosteric molecular basis for disease-related mutations and the discovery of novel leads for allosteric drugs. From this overview, it is clear that NMR plays a central role not only in experimentally validating transformative theories of allostery, but also in tapping the full translational potential of allosteric systems.
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Affiliation(s)
- Stephen Boulton
- Department of Chemistry and Chemical Biology Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main St. W., Hamilton L8S 4M1, Canada
| | - Giuseppe Melacini
- Department of Chemistry and Chemical Biology Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main St. W., Hamilton L8S 4M1, Canada
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31
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Patel D, Kopec J, Fitzpatrick F, McCorvie TJ, Yue WW. Structural basis for ligand-dependent dimerization of phenylalanine hydroxylase regulatory domain. Sci Rep 2016; 6:23748. [PMID: 27049649 PMCID: PMC4822156 DOI: 10.1038/srep23748] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 03/08/2016] [Indexed: 02/01/2023] Open
Abstract
The multi-domain enzyme phenylalanine hydroxylase (PAH) catalyzes the hydroxylation of dietary I-phenylalanine (Phe) to I-tyrosine. Inherited mutations that result in PAH enzyme deficiency are the genetic cause of the autosomal recessive disorder phenylketonuria. Phe is the substrate for the PAH active site, but also an allosteric ligand that increases enzyme activity. Phe has been proposed to bind, in addition to the catalytic domain, a site at the PAH N-terminal regulatory domain (PAH-RD), to activate the enzyme via an unclear mechanism. Here we report the crystal structure of human PAH-RD bound with Phe at 1.8 Å resolution, revealing a homodimer of ACT folds with Phe bound at the dimer interface. This work delivers the structural evidence to support previous solution studies that a binding site exists in the RD for Phe, and that Phe binding results in dimerization of PAH-RD. Consistent with our structural observation, a disease-associated PAH mutant impaired in Phe binding disrupts the monomer:dimer equilibrium of PAH-RD. Our data therefore support an emerging model of PAH allosteric regulation, whereby Phe binds to PAH-RD and mediates the dimerization of regulatory modules that would bring about conformational changes to activate the enzyme.
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Affiliation(s)
- Dipali Patel
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, UK OX3 7DQ
| | - Jolanta Kopec
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, UK OX3 7DQ
| | - Fiona Fitzpatrick
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, UK OX3 7DQ
| | - Thomas J McCorvie
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, UK OX3 7DQ
| | - Wyatt W Yue
- Structural Genomics Consortium, Nuffield Department of Clinical Medicine, University of Oxford, UK OX3 7DQ
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32
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First structure of full-length mammalian phenylalanine hydroxylase reveals the architecture of an autoinhibited tetramer. Proc Natl Acad Sci U S A 2016; 113:2394-9. [PMID: 26884182 DOI: 10.1073/pnas.1516967113] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Improved understanding of the relationship among structure, dynamics, and function for the enzyme phenylalanine hydroxylase (PAH) can lead to needed new therapies for phenylketonuria, the most common inborn error of amino acid metabolism. PAH is a multidomain homo-multimeric protein whose conformation and multimerization properties respond to allosteric activation by the substrate phenylalanine (Phe); the allosteric regulation is necessary to maintain Phe below neurotoxic levels. A recently introduced model for allosteric regulation of PAH involves major domain motions and architecturally distinct PAH tetramers [Jaffe EK, Stith L, Lawrence SH, Andrake M, Dunbrack RL, Jr (2013) Arch Biochem Biophys 530(2):73-82]. Herein, we present, to our knowledge, the first X-ray crystal structure for a full-length mammalian (rat) PAH in an autoinhibited conformation. Chromatographic isolation of a monodisperse tetrameric PAH, in the absence of Phe, facilitated determination of the 2.9 Å crystal structure. The structure of full-length PAH supersedes a composite homology model that had been used extensively to rationalize phenylketonuria genotype-phenotype relationships. Small-angle X-ray scattering (SAXS) confirms that this tetramer, which dominates in the absence of Phe, is different from a Phe-stabilized allosterically activated PAH tetramer. The lack of structural detail for activated PAH remains a barrier to complete understanding of phenylketonuria genotype-phenotype relationships. Nevertheless, the use of SAXS and X-ray crystallography together to inspect PAH structure provides, to our knowledge, the first complete view of the enzyme in a tetrameric form that was not possible with prior partial crystal structures, and facilitates interpretation of a wealth of biochemical and structural data that was hitherto impossible to evaluate.
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33
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Zhang S, Fitzpatrick PF. Identification of the Allosteric Site for Phenylalanine in Rat Phenylalanine Hydroxylase. J Biol Chem 2016; 291:7418-25. [PMID: 26823465 DOI: 10.1074/jbc.m115.709998] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Indexed: 11/06/2022] Open
Abstract
Liver phenylalanine hydroxylase (PheH) is an allosteric enzyme that requires activation by phenylalanine for full activity. The location of the allosteric site for phenylalanine has not been established. NMR spectroscopy of the isolated regulatory domain (RDPheH(25-117) is the regulatory domain of PheH lacking residues 1-24) of the rat enzyme in the presence of phenylalanine is consistent with formation of a side-by-side ACT dimer. Six residues in RDPheH(25-117) were identified as being in the phenylalanine-binding site on the basis of intermolecular NOEs between unlabeled phenylalanine and isotopically labeled protein. The location of these residues is consistent with two allosteric sites per dimer, with each site containing residues from both monomers. Site-specific variants of five of the residues (E44Q, A47G, L48V, L62V, and H64N) decreased the affinity of RDPheH(25-117) for phenylalanine based on the ability to stabilize the dimer. Incorporation of the A47G, L48V, and H64N mutations into the intact protein increased the concentration of phenylalanine required for activation. The results identify the location of the allosteric site as the interface of the regulatory domain dimer formed in activated PheH.
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Affiliation(s)
- Shengnan Zhang
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Paul F Fitzpatrick
- From the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
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34
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Zhang S, Hinck AP, Fitzpatrick PF. The Amino Acid Specificity for Activation of Phenylalanine Hydroxylase Matches the Specificity for Stabilization of Regulatory Domain Dimers. Biochemistry 2015; 54:5167-74. [PMID: 26252467 PMCID: PMC4551101 DOI: 10.1021/acs.biochem.5b00616] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Liver
phenylalanine hydroxylase is allosterically activated by
phenylalanine. The structural changes that accompany activation have
not been identified, but recent studies of the effects of phenylalanine
on the isolated regulatory domain of the enzyme support a model in
which phenylalanine binding promotes regulatory domain dimerization.
Such a model predicts that compounds that stabilize the regulatory
domain dimer will also activate the enzyme. Nuclear magnetic resonance
spectroscopy and analytical ultracentrifugation were used to determine
the ability of different amino acids and phenylalanine analogues to
stabilize the regulatory domain dimer. The abilities of these compounds
to activate the enzyme were analyzed by measuring their effects on
the fluorescence change that accompanies activation and on the activity
directly. At concentrations of 10–50 mM, d-phenylalanine, l-methionine, l-norleucine, and (S)-2-amino-3-phenyl-1-propanol were able to activate the enzyme to
the same extent as 1 mM l-phenylalanine. Lower levels of
activation were seen with l-4-aminophenylalanine, l-leucine, l-isoleucine, and 3-phenylpropionate. The ability
of these compounds to stabilize the regulatory domain dimer agreed
with their ability to activate the enzyme. These results support a
model in which allosteric activation of phenylalanine hydroxylase
is linked to dimerization of regulatory domains.
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Affiliation(s)
- Shengnan Zhang
- Department of Biochemistry, University of Texas Health Science Center , San Antonio, Texas 78229, United States
| | - Andrew P Hinck
- Department of Biochemistry, University of Texas Health Science Center , San Antonio, Texas 78229, United States
| | - Paul F Fitzpatrick
- Department of Biochemistry, University of Texas Health Science Center , San Antonio, Texas 78229, United States
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35
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Fitzpatrick PF. Structural insights into the regulation of aromatic amino acid hydroxylation. Curr Opin Struct Biol 2015; 35:1-6. [PMID: 26241318 DOI: 10.1016/j.sbi.2015.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/30/2015] [Accepted: 07/15/2015] [Indexed: 11/30/2022]
Abstract
The aromatic amino acid hydroxylases phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase are homotetramers, with each subunit containing a homologous catalytic domain and a divergent regulatory domain. The solution structure of the regulatory domain of tyrosine hydroxylase establishes that it contains a core ACT domain similar to that in phenylalanine hydroxylase. The isolated regulatory domain of tyrosine hydroxylase forms a stable dimer, while that of phenylalanine hydroxylase undergoes a monomer-dimer equilibrium, with phenylalanine stabilizing the dimer. These solution properties are consistent with the regulatory mechanisms of the two enzymes, in that phenylalanine hydroxylase is activated by phenylalanine binding to an allosteric site, while tyrosine hydroxylase is regulated by binding of catecholamines in the active site.
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Affiliation(s)
- Paul F Fitzpatrick
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229, United States.
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36
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Lang EJM, Cross PJ, Mittelstädt G, Jameson GB, Parker EJ. Allosteric ACTion: the varied ACT domains regulating enzymes of amino-acid metabolism. Curr Opin Struct Biol 2014; 29:102-11. [PMID: 25543886 DOI: 10.1016/j.sbi.2014.10.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 10/28/2014] [Indexed: 11/29/2022]
Abstract
Allosteric regulation of enzyme activity plays important metabolic roles. Here we review the allostery of enzymes of amino-acid metabolism conferred by a discrete domain known as the ACT domain. This domain of 60-70 residues has a βαββαβ topology leading to a four-stranded β4β1β3β2 antiparallel sheet with two antiparallel helices on one face. Extensive sequence variation requires a combined sequence/structure/function analysis for identification of the ACT domain. Common features include highly varied modes of self-association of ACT domains, ligand binding at domain interfaces, and transmittal of allosteric signals through conformational changes and/or the manipulation of quaternary equilibria. A recent example illustrates the relatively facile adoption of this versatile module of allostery by gene fusion.
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Affiliation(s)
- Eric J M Lang
- Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand
| | - Penelope J Cross
- Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand
| | - Gerd Mittelstädt
- Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand
| | - Geoffrey B Jameson
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Emily J Parker
- Maurice Wilkins Centre, Biomolecular Interaction Centre, Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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37
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Zhang S, Roberts KM, Fitzpatrick PF. Phenylalanine binding is linked to dimerization of the regulatory domain of phenylalanine hydroxylase. Biochemistry 2014; 53:6625-7. [PMID: 25299136 PMCID: PMC4251497 DOI: 10.1021/bi501109s] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Analytical ultracentrifugation has
been used to analyze the oligomeric
structure of the isolated regulatory domain of phenylalanine hydroxylase.
The protein exhibits a monomer–dimer equilibrium with a dissociation
constant of ∼46 μM; this value is unaffected by the removal
of the 24 N-terminal residues or by phosphorylation of Ser16. In contrast,
phenylalanine binding (Kd = 8 μM)
stabilizes the dimer. These results suggest that dimerization of the
regulatory domain of phenylalanine hydroxylase is linked to allosteric
activation of the enzyme.
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Affiliation(s)
- Shengnan Zhang
- Department of Biochemistry, University of Texas Health Science Center at San Antonio , San Antonio, Texas 78229, United States
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38
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Kleppe R, Rosati S, Jorge-Finnigan A, Alvira S, Ghorbani S, Haavik J, Valpuesta JM, Heck AJR, Martinez A. Phosphorylation dependence and stoichiometry of the complex formed by tyrosine hydroxylase and 14-3-3γ. Mol Cell Proteomics 2014; 13:2017-30. [PMID: 24947669 PMCID: PMC4125734 DOI: 10.1074/mcp.m113.035709] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphorylated tyrosine hydroxylase (TH) can form complexes with 14-3-3 proteins, resulting in enzyme activation and stabilization. Although TH was among the first binding partners identified for these ubiquitous regulatory proteins, the binding stoichiometry and the activation mechanism remain unknown. To address this, we performed native mass spectrometry analyses of human TH (nonphosphorylated or phosphorylated on Ser19 (TH-pS19), Ser40 (TH-pS40), or Ser19 and Ser40 (TH-pS19pS40)) alone and together with 14-3-3γ. Tetrameric TH-pS19 (224 kDa) bound 14-3-3γ (58.3 kDa) with high affinity (Kd = 3.2 nM), generating complexes containing either one (282.4 kDa) or two (340.8 kDa) dimers of 14-3-3. Electron microscopy also revealed one major population of an asymmetric complex, consistent with one TH tetramer and one 14-3-3 dimer, and a minor population of a symmetric complex of one TH tetramer with two 14-3-3 dimers. Lower phosphorylation stoichiometries (0.15–0.54 phosphate/monomer) produced moderate changes in binding kinetics, but native MS detected much less of the symmetric TH:14-3-3γ complex. Interestingly, dephosphorylation of [32P]-TH-pS19 was mono-exponential for low phosphorylation stoichiometries (0.18–0.52), and addition of phosphatase accelerated the dissociation of the TH-pS19:14-3-3γ complex 3- to 4-fold. All together this is consistent with a model in which the pS19 residues in the TH tetramer contribute differently in the association to 14-3-3γ. Complex formation between TH-pS40 and 14-3-3γ was not detected via native MS, and surface plasmon resonance showed that the interaction was very weak. Furthermore, TH-pS19pS40 behaved similarly to TH-pS19 in terms of binding stoichiometry and affinity (Kd = 2.1 nM). However, we found that 14-3-3γ inhibited the phosphorylation rate of TH-pS19 by PKA (3.5-fold) on Ser40. We therefore conclude that Ser40 does not significantly contribute to the binding of 14-3-3γ, and rather has reduced accessibility in the TH:14-3-3γ complex. This adds to our understanding of the fine-tuned physiological regulation of TH, including hierarchical phosphorylation at multiple sites.
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Affiliation(s)
- Rune Kleppe
- From the ‡Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; §K. G. Jebsen Centre for Research on Neuropsychiatric disorders, Jonas Lies vei 91, 5009 Bergen, Norway; ¶Division for Psychiatry, Haukeland University Hospital, Sandviksleitet 1, 5036 Bergen, Norway
| | - Sara Rosati
- **Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; ‡‡Netherland Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Ana Jorge-Finnigan
- From the ‡Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Sara Alvira
- §§Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049 Madrid, Spain
| | - Sadaf Ghorbani
- From the ‡Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Jan Haavik
- From the ‡Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; §K. G. Jebsen Centre for Research on Neuropsychiatric disorders, Jonas Lies vei 91, 5009 Bergen, Norway; ¶Division for Psychiatry, Haukeland University Hospital, Sandviksleitet 1, 5036 Bergen, Norway
| | | | - Albert J R Heck
- **Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; ‡‡Netherland Proteomics Center, Padualaan 8, 3584 CH Utrecht, The Netherlands;
| | - Aurora Martinez
- From the ‡Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway; §K. G. Jebsen Centre for Research on Neuropsychiatric disorders, Jonas Lies vei 91, 5009 Bergen, Norway;
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39
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Complex molecular regulation of tyrosine hydroxylase. J Neural Transm (Vienna) 2014; 121:1451-81. [PMID: 24866693 DOI: 10.1007/s00702-014-1238-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/04/2014] [Indexed: 12/16/2022]
Abstract
Tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, is strictly controlled by several interrelated regulatory mechanisms. Enzyme synthesis is controlled by epigenetic factors, transcription factors, and mRNA levels. Enzyme activity is regulated by end-product feedback inhibition. Phosphorylation of the enzyme is catalyzed by several protein kinases and dephosphorylation is mediated by two protein phosphatases that establish a sensitive process for regulating enzyme activity on a minute-to-minute basis. Interactions between tyrosine hydroxylase and other proteins introduce additional layers to the already tightly controlled production of catecholamines. Tyrosine hydroxylase degradation by the ubiquitin-proteasome coupled pathway represents yet another mechanism of regulation. Here, we revisit the myriad mechanisms that regulate tyrosine hydroxylase expression and activity and highlight their physiological importance in the control of catecholamine biosynthesis.
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