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Abuhammad A, Laurieri N, Rice A, Lowe ED, Singh N, Naser SM, Ratrout SS, Churchill GC. Structural and biochemical analysis of human inositol monophosphatase-1 inhibition by ebselen. J Biomol Struct Dyn 2023; 41:14036-14048. [PMID: 36762717 DOI: 10.1080/07391102.2023.2176925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 01/30/2023] [Indexed: 02/11/2023]
Abstract
Bipolar disorder is a major psychiatric disorder associated with cognitive impairment and a high suicide rate. Frontline therapy for this condition includes lithium (Li+)-containing treatments that can exert severe side effects. One target of Li+ is inositol monophosphatase-1 (IMPase1); inhibition of IMPase1 through small-molecule compounds may provide an alternative treatment for bipolar disorder. One such compound is the anti-inflammatory drug ebselen, which is well tolerated and safe; however, ebselen's exact mechanism of action in IMPase1 inhibition is not fully understood, preventing rational design of IMPase1 inhibitors. To fill this gap, we performed crystallographic and biochemical studies to investigate how ebselen inhibits IMPase1. We obtained a structure of IMPase1 in space group P21 after treatment with ebselen that revealed three key active-site loops (residues 33-44, 70-79, and 161-165) that are either disordered or in multiple conformations, supporting a hypothesis whereby dynamic conformational changes may be important for catalysis and ebselen inhibition. Using the thermal shift assay, we confirmed that ebselen significantly destabilizes the enzyme. Molecular docking suggests that ebselen could bind in the vicinity of His217. Investigation of the role of IMPase1 residues His217 and Cys218 suggests that inhibition of IMPase1 by ebselen may not be mediated via covalent modification of the active-site cysteine (Cys218) and is not affected by the covalent modification of other cysteine residues in the structure. Our results suggest that effects previously ascribed to ebselen-dependent inhibition likely result from disruption of essential active-site architecture, preventing activation of the IMPase1-Mg2+ complex.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Areej Abuhammad
- Department of Pharmaceutical Sciences, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Nicola Laurieri
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Alistair Rice
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Edward D Lowe
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Nisha Singh
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Saleem M Naser
- Research and Development Department, APIs Division, Hikma Pharmaceutical Co. Ltd, Amman, Jordan
| | - Samer S Ratrout
- Research and Development Department, APIs Division, Hikma Pharmaceutical Co. Ltd, Amman, Jordan
| | - Grant C Churchill
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
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Li N, Zhou J, Wang H, Mu C, Wang C. The iTRAQ-based quantitative proteomics reveals metabolic changes in Scylla paramamosain under different light intensities during indoor overwintering. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 207:111384. [PMID: 33011457 DOI: 10.1016/j.ecoenv.2020.111384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Light intensity is one of the ecological factors that appreciably affects the metabolism of Scylla paramamosain during overwintering. This study adopted the isobaric tag for relative and absolute quantitation (iTRAQ) method to investigate metabolic changes of S. paramamosain under three illumination levels (0, 1.43 and 40.31 μmol m-2·s-1) for four months during indoor overwintering. The iTRAQ identified 3282 proteins, among which 267 exhibited significant differential expression (122 upregulated and 145 downregulated) in the low light group, and 299 with significant differential expression (252 upregulated and 47 downregulated) in the high light group. Analysis of these results showed that there were different metabolic regulatory patterns under different light intensities. Low light is more conducive to the survival of S. paramamosain, which needs to produce and consume relatively less energy to sustain physiological activities. Thus, the essential proteins associated with physiological activities were significantly upregulated, while those related to energy production were significantly downregulated. In contrast, high light exerts a certain stress on the survival of S. paramamosain and required more energy to cope with this stress, which forced a significant upregulation of proteins related to stress response and energy production. The findings of this study highlighted the metabolic regulatory mechanisms of S. paramamosain under different light intensities.
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Affiliation(s)
- Na Li
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Junming Zhou
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Huan Wang
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Changkao Mu
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
| | - Chunlin Wang
- School of Marine Science, Ningbo University, Ningbo, 315211, Zhejiang, China; Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, 315211, Zhejiang, China.
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Ma A, Cui W, Wang X, Zhang W, Liu Z, Zhang J, Zhao T. Osmoregulation by the myo-inositol biosynthesis pathway in turbot Scophthalmus maximus and its regulation by anabolite and c-Myc. Comp Biochem Physiol A Mol Integr Physiol 2019; 242:110636. [PMID: 31846703 DOI: 10.1016/j.cbpa.2019.110636] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 12/08/2019] [Accepted: 12/12/2019] [Indexed: 12/12/2022]
Abstract
The induction of the myo-inositol biosynthesis (MIB) pathway in euryhaline fishes is an important component of the cellular response to osmotic challenge. The MIPS and IMPA1 genes were sequenced in turbot and found to be highly conserved in phylogenetic evolution, especially within the fish species tested. Under salinity stress in turbot, both MIPS and IMPA1 showed adaptive expression, a turning point in the level of expression occurred at 12 h in all tissues tested. We performed an RNAi assay mediated by long fragment dsRNA prepared by transcription in vitro. The findings demonstrated that knockdown of the MIB pathway weakened the function of gill osmotic regulation, and may induce a genetic compensation response in the kidney and gill to maintain physiological function. Even though the gill and kidney conducted stress reactions or compensatory responses to salinity stress, this inadequately addressed the consequences of MIB knockdown. Therefore, the survival time of turbot under salinity stress after knockdown was obviously less than that under seawater, especially under low salt stress. Pearson's correlation analysis between gene expression and dietary myo-inositol concentration indicated that the MIB pathway had a remarkable negative feedback control, and the dynamic equilibrium mediated by negative feedback on the MIB pathway played a crucial role in osmoregulation in turbot. An RNAi assay with c-Myc in vivo and the use of a c-Myc inhibitor (10058-F4) in vitro demonstrated that c-Myc was likely to positively regulate the MIB pathway in turbot.
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Affiliation(s)
- Aijun Ma
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
| | - Wenxiao Cui
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Xinan Wang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Wei Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Zhifeng Liu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Jinsheng Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Tingting Zhao
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shandong Key Laboratory of Marine Fisheries Biotechnology and Genetic Breeding, Qingdao Key Laboratory for Marine Fish Breeding and Biotechnology, Qingdao 266071, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
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Kraft L, Roe SM, Gill R, Atack JR. Co-crystallization of human inositol monophosphatase with the lithium mimetic L-690,330. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:973-978. [PMID: 30289407 DOI: 10.1107/s2059798318010380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/18/2018] [Indexed: 11/10/2022]
Abstract
Lithium, which is still the gold standard in the treatment of bipolar disorder, has been proposed to inhibit inositol monophosphatase (IMPase) and is hypothesized to exert its therapeutic effects by attenuating phosphatidylinositol (PI) cell signalling. Drug-discovery efforts have focused on small-molecule lithium mimetics that would specifically inhibit IMPase without exhibiting the undesired side effects of lithium. L-690,330 is a potent bisphosphonate substrate-based inhibitor developed by Merck Sharp & Dohme. To aid future structure-based inhibitor design, determination of the exact binding mechanism of L-690,330 to IMPase was of interest. Here, the high-resolution X-ray structure of human IMPase in complex with L690,330 and manganese ions determined at 1.39 Å resolution is reported.
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Affiliation(s)
- Lucas Kraft
- Sussex Drug Discovery Centre, University of Sussex, Chichester II, Falmer, Brighton BN1 9QJ, England
| | - S Mark Roe
- University of Sussex, Arundel Building, Falmer, Brighton BN1 9QJ, England
| | - Raj Gill
- Sussex Drug Discovery Centre, University of Sussex, Chichester II, Falmer, Brighton BN1 9QJ, England
| | - John R Atack
- School of Biosciences, Medicines Discovery Institute, Park Place, Cardiff CF10 3AT, Wales
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Lu Y, Wang L, Teng F, Zhang J, Hu M, Tao Y. Production of myo-inositol from glucose by a novel trienzymatic cascade of polyphosphate glucokinase, inositol 1-phosphate synthase and inositol monophosphatase. Enzyme Microb Technol 2018; 112:1-5. [DOI: 10.1016/j.enzmictec.2018.01.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/20/2017] [Accepted: 01/15/2018] [Indexed: 02/06/2023]
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6
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Kulis-Horn RK, Rückert C, Kalinowski J, Persicke M. Sequence-based identification of inositol monophosphatase-like histidinol-phosphate phosphatases (HisN) in Corynebacterium glutamicum, Actinobacteria, and beyond. BMC Microbiol 2017; 17:161. [PMID: 28720084 PMCID: PMC5516325 DOI: 10.1186/s12866-017-1069-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/10/2017] [Indexed: 12/30/2022] Open
Abstract
Background The eighth step of l-histidine biosynthesis is carried out by an enzyme called histidinol-phosphate phosphatase (HolPase). Three unrelated HolPase families are known so far. Two of them are well studied: HAD-type HolPases known from Gammaproteobacteria like Escherichia coli or Salmonella enterica and PHP-type HolPases known from yeast and Firmicutes like Bacillus subtilis. However, the third family of HolPases, the inositol monophosphatase (IMPase)-like HolPases, present in Actinobacteria like Corynebacterium glutamicum (HisN) and plants, are poorly characterized. Moreover, there exist several IMPase-like proteins in bacteria (e.g. CysQ, ImpA, and SuhB) which are very similar to HisN but most likely do not participate in l-histidine biosynthesis. Results Deletion of hisN, the gene encoding the IMPase-like HolPase in C. glutamicum, does not result in complete l-histidine auxotrophy. Out of four hisN homologs present in the genome of C. glutamicum (impA, suhB, cysQ, and cg0911), only cg0911 encodes an enzyme with HolPase activity. The enzymatic properties of HisN and Cg0911 were determined, delivering the first available kinetic data for IMPase-like HolPases. Additionally, we analyzed the amino acid sequences of potential HisN, ImpA, SuhB, CysQ and Cg0911 orthologs from bacteria and identified six conserved sequence motifs for each group of orthologs. Mutational studies confirmed the importance of a highly conserved aspartate residue accompanied by several aromatic amino acid residues present in motif 5 for HolPase activity. Several bacterial proteins containing all identified HolPase motifs, but showing only moderate sequence similarity to HisN from C. glutamicum, were experimentally confirmed as IMPase-like HolPases, demonstrating the value of the identified motifs. Based on the confirmed IMPase-like HolPases two profile Hidden Markov Models (HMMs) were build using an iterative approach. These HMMs allow the fast, reliable detection and differentiation of the two paralog groups from each other and other IMPases. Conclusion The kinetic data obtained for HisN from C. glutamicum, as an example for an IMPase-like HolPases, shows remarkable differences in enzyme properties as compared to HAD- or PHP-type HolPases. The six sequence motifs and the HMMs presented in this study can be used to reliably differentiate between IMPase-like HolPases and IMPase-like proteins with no such activity, with the potential to enhance current and future genome annotations. A phylogenetic analysis reveals that IMPase-like HolPases are not only present in Actinobacteria and plant but can be found in further bacterial phyla, including, among others, Proteobacteria, Chlorobi and Planctomycetes. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-1069-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Robert Kasimir Kulis-Horn
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Christian Rückert
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany
| | - Marcus Persicke
- Microbial Genomics and Biotechnology, Center for Biotechnology, Bielefeld University, Universitätsstraße 27, 33615, Bielefeld, Germany.
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7
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Ferruz N, Tresadern G, Pineda-Lucena A, De Fabritiis G. Multibody cofactor and substrate molecular recognition in the myo-inositol monophosphatase enzyme. Sci Rep 2016; 6:30275. [PMID: 27440438 PMCID: PMC4954947 DOI: 10.1038/srep30275] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/29/2016] [Indexed: 01/22/2023] Open
Abstract
Molecular recognition is rarely a two-body protein-ligand problem, as it often involves the dynamic interplay of multiple molecules that together control the binding process. Myo-inositol monophosphatase (IMPase), a drug target for bipolar disorder, depends on 3 Mg(2+) ions as cofactor for its catalytic activity. Although the crystallographic pose of the pre-catalytic complex is well characterized, the binding process by which substrate, cofactor and protein cooperate is essentially unknown. Here, we have characterized cofactor and substrate cooperative binding by means of large-scale molecular dynamics. Our study showed the first and second Mg(2+) ions identify the binding pocket with fast kinetics whereas the third ion presents a much higher energy barrier. Substrate binding can occur in cooperation with cofactor, or alone to a binary or ternary cofactor-IMPase complex, although the last scenario occurs several orders of magnitude faster. Our atomic description of the three-body mechanism offers a particularly challenging example of pathway reconstruction, and may prove particularly useful in realistic contexts where water, ions, cofactors or other entities cooperate and modulate the binding process.
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Affiliation(s)
- Noelia Ferruz
- Computational Biophysics Laboratory (GRIB-IMIM), Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), Doctor Aiguader 88, 08003, Barcelona, Spain
- Acellera, Barcelona Biomedical Research Park, C Dr Aiguader 88, 08003, Barcelona, Spain
| | - Gary Tresadern
- Research Informatics, Janssen Research and Development, Janssen Cilag S A, Calle Jarama 75, Poligono Industrial, Toledo 45007, Spain
| | | | - Gianni De Fabritiis
- Computational Biophysics Laboratory (GRIB-IMIM), Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), Doctor Aiguader 88, 08003, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010 Barcelona, Spain
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Villarreal FD, Kültz D. Direct Ionic Regulation of the Activity of Myo-Inositol Biosynthesis Enzymes in Mozambique Tilapia. PLoS One 2015; 10:e0123212. [PMID: 26066044 PMCID: PMC4466255 DOI: 10.1371/journal.pone.0123212] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 02/28/2015] [Indexed: 11/27/2022] Open
Abstract
Myo-inositol (Ins) is a major compatible osmolyte in many cells, including those of Mozambique tilapia (Oreochromis mossambicus). Ins biosynthesis is highly up-regulated in tilapia and other euryhaline fish exposed to hyperosmotic stress. In this study, enzymatic regulation of two enzymes of Ins biosynthesis, Ins phosphate synthase (MIPS) and inositol monophosphatase (IMPase), by direct ionic effects is analyzed. Specific MIPS and IMPase isoforms from Mozambique tilapia (MIPS-160 and IMPase 1) were selected based on experimental, phylogenetic, and structural evidence supporting their role for Ins biosynthesis during hyperosmotic stress. Recombinant tilapia IMPase 1 and MIPS-160 activity was assayed in vitro at ionic conditions that mimic changes in the intracellular milieu during hyperosmotic stress. The in vitro activities of MIPS-160 and IMPase 1 are highest at alkaline pH of 8.8. IMPase 1 catalytic efficiency is strongly increased during hyperosmolality (particularly for the substrate D-Ins-3-phosphate, Ins-3P), mainly as a result of [Na+] elevation. Furthermore, the substrate-specificity of IMPase 1 towards D-Ins-1-phosphate (Ins-1P) is lower than towards Ins-3P. Because MIPS catalysis results in Ins-3P this results represents additional evidence for IMPase 1 being the isoform that mediates Ins biosynthesis in tilapia. Our data collectively demonstrate that the Ins biosynthesis enzymes are activated under ionic conditions that cells are exposed to during hypertonicity, resulting in Ins accumulation, which, in turn, results in restoration of intracellular ion homeostasis. We propose that the unique and direct ionic regulation of the activities of Ins biosynthesis enzymes represents an efficient biochemical feedback loop for regulation of intracellular physiological ion homeostasis during hyperosmotic stress.
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Affiliation(s)
- Fernando D. Villarreal
- EcoPhysiological Proteomics Laboratory, Department of Animal Science, University of California Davis, One Shields Avenue, Davis, California 95616, United States of America
| | - Dietmar Kültz
- EcoPhysiological Proteomics Laboratory, Department of Animal Science, University of California Davis, One Shields Avenue, Davis, California 95616, United States of America
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Haimovich A, Goldbourt A. Characterization of lithium coordination sites with magic-angle spinning NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 254:131-138. [PMID: 25899290 DOI: 10.1016/j.jmr.2015.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/28/2015] [Accepted: 02/07/2015] [Indexed: 06/04/2023]
Abstract
Lithium, in the form of lithium carbonate, is one of the most common drugs for bipolar disorder. Lithium is also considered to have an effect on many other cellular processes hence it possesses additional therapeutic as well as side effects. In order to quantitatively characterize the binding mode of lithium, it is required to identify the interacting species and measure their distances from the metal center. Here we use magic-angle spinning (MAS) solid-state NMR to study the binding site of lithium in complex with glycine and water (LiGlyW). Such a compound is a good enzyme mimetic since lithium is four-coordinated to one water molecule and three carboxylic groups. Distance measurements to carbons are performed using a 2D transferred echo double resonance (TEDOR) MAS solid-state NMR experiment, and water binding is probed by heteronuclear high-resolution proton-lithium and proton-carbon correlation (wPMLG-HETCOR) experiments. Both HETCOR experiments separate the main complex from impurities and non-specifically bound lithium species, demonstrating the sensitivity of the method to probe the species in the binding site. Optimizations of the TEDOR pulse scheme in the case of a quadrupolar nucleus with a small quadrupole coupling constant show that it is most efficient when pulses are positioned on the spin-1/2 (carbon-13) nucleus. Since the intensity of the TEDOR signal is not normalized, careful data analysis that considers both intensity and dipolar oscillations has to be performed. Nevertheless we show that accurate distances can be extracted for both carbons of the bound glycine and that these distances are consistent with the X-ray data and with lithium in a tetrahedral environment. The lithium environment in the complex is very similar to the binding site in inositol monophosphatase, an enzyme associated with bipolar disorder and the putative target for lithium therapy. A 2D TEDOR experiment applied to the bacterial SuhB gene product of this enzyme was designed to probe direct correlations between lithium, the enzyme inhibitor, and the closest carboxyl carbons of the binding site. At this point, the chemical shift of the bound carboxyl groups in this 29 kDa enzyme could be determined.
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Affiliation(s)
- A Haimovich
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - A Goldbourt
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel.
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Dutta A, Bhattacharyya S, Dutta D, Das AK. Structural elucidation of the binding site and mode of inhibition of Li+and Mg2+in inositol monophosphatase. FEBS J 2014; 281:5309-24. [PMID: 25263816 DOI: 10.1111/febs.13070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 09/16/2014] [Accepted: 09/23/2014] [Indexed: 01/20/2023]
Affiliation(s)
- Anirudha Dutta
- Department of Biotechnology; Indian Institute of Technology Kharagpur; Kharagpur West Bengal India
| | - Sudipta Bhattacharyya
- Department of Biotechnology; Indian Institute of Technology Kharagpur; Kharagpur West Bengal India
| | - Debajyoti Dutta
- Department of Biotechnology; Indian Institute of Technology Kharagpur; Kharagpur West Bengal India
| | - Amit Kumar Das
- Department of Biotechnology; Indian Institute of Technology Kharagpur; Kharagpur West Bengal India
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Ohnishi T, Murata T, Watanabe A, Hida A, Ohba H, Iwayama Y, Mishima K, Gondo Y, Yoshikawa T. Defective craniofacial development and brain function in a mouse model for depletion of intracellular inositol synthesis. J Biol Chem 2014; 289:10785-10796. [PMID: 24554717 DOI: 10.1074/jbc.m113.536706] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
myo-Inositol is an essential biomolecule that is synthesized by myo-inositol monophosphatase (IMPase) from inositol monophosphate species. The enzymatic activity of IMPase is inhibited by lithium, a drug used for the treatment of mood swings seen in bipolar disorder. Therefore, myo-inositol is thought to have an important role in the mechanism of bipolar disorder, although the details remain elusive. We screened an ethyl nitrosourea mutant mouse library for IMPase gene (Impa) mutations and identified an Impa1 T95K missense mutation. The mutant protein possessed undetectable enzymatic activity. Homozygotes died perinatally, and E18.5 embryos exhibited striking developmental defects, including hypoplasia of the mandible and asymmetric fusion of ribs to the sternum. Perinatal lethality and morphological defects in homozygotes were rescued by dietary myo-inositol. Rescued homozygotes raised on normal drinking water after weaning exhibited a hyper-locomotive trait and prolonged circadian periods, as reported in rodents treated with lithium. Our mice should be advantageous, compared with those generated by the conventional gene knock-out strategy, because they carry minimal genomic damage, e.g. a point mutation. In conclusion, our results reveal critical roles for intracellular myo-inositol synthesis in craniofacial development and the maintenance of proper brain function. Furthermore, this mouse model for cellular inositol depletion could be beneficial for understanding the molecular mechanisms underlying the clinical effect of lithium and myo-inositol-mediated skeletal development.
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Affiliation(s)
- Tetsuo Ohnishi
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Saitama 351-0198.
| | - Takuya Murata
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074
| | - Akiko Watanabe
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Saitama 351-0198
| | - Akiko Hida
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8553, Japan
| | - Hisako Ohba
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Saitama 351-0198
| | - Yoshimi Iwayama
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Saitama 351-0198
| | - Kazuo Mishima
- Department of Psychophysiology, National Institute of Mental Health, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8553, Japan
| | - Yoichi Gondo
- Mutagenesis and Genomics Team, RIKEN BioResource Center, Tsukuba, Ibaraki 305-0074
| | - Takeo Yoshikawa
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, Wako, Saitama 351-0198
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Singh N, Halliday AC, Thomas JM, Kuznetsova OV, Baldwin R, Woon ECY, Aley PK, Antoniadou I, Sharp T, Vasudevan SR, Churchill GC. A safe lithium mimetic for bipolar disorder. Nat Commun 2013; 4:1332. [PMID: 23299882 PMCID: PMC3605789 DOI: 10.1038/ncomms2320] [Citation(s) in RCA: 188] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 11/22/2012] [Indexed: 12/29/2022] Open
Abstract
Lithium is the most effective mood stabilizer for the treatment of bipolar disorder, but it is toxic at only twice the therapeutic dosage and has many undesirable side effects. It is likely that a small molecule could be found with lithium-like efficacy but without toxicity through target-based drug discovery; however, lithium’s therapeutic target remains equivocal. Inositol monophosphatase is a possible target but no bioavailable inhibitors exist. Here we report that the antioxidant ebselen inhibits inositol monophosphatase and induces lithium-like effects on mouse behaviour, which are reversed with inositol, consistent with a mechanism involving inhibition of inositol recycling. Ebselen is part of the National Institutes of Health Clinical Collection, a chemical library of bioavailable drugs considered clinically safe but without proven use. Therefore, ebselen represents a lithium mimetic with the potential both to validate inositol monophosphatase inhibition as a treatment for bipolar disorder and to serve as a treatment itself.
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Affiliation(s)
- Nisha Singh
- University of Oxford, Department of Pharmacology, Mansfield Road, Oxford OX1 3QT, UK
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Kalujnaia S, Gellatly SA, Hazon N, Villasenor A, Yancey PH, Cramb G. Seawater acclimation and inositol monophosphatase isoform expression in the European eel (Anguilla anguilla) and Nile tilapia (Orechromis niloticus). Am J Physiol Regul Integr Comp Physiol 2013; 305:R369-84. [PMID: 23739342 DOI: 10.1152/ajpregu.00044.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Inositol monophosphatase (IMPA) is responsible for the synthesis of inositol, a polyol that can function as an intracellular osmolyte helping re-establish cell volume when exposed to hypertonic environments. Some epithelial tissues in euryhaline teleosts such as the eel and tilapia encounter considerable hyperosmotic challenge when fish move from freshwater (FW) to seawater (SW) environments; however, the roles played by organic osmolytes, such as inositol, have yet to be determined. Syntenic analysis has indicated that, as a result of whole genome- and tandem-duplication events, up to six IMPA isoforms can exist within teleost genomes. Four isoforms are homologs of the mammalian IMPA1 gene, and two isoforms are homologs of the mammalian IMPA2 gene. Although the tissue-dependent isoform expression profiles of the teleost isoforms appear to be species-specific, it was primarily mRNA for the IMPA1.1 isoform that was upregulated in epithelial tissues after fish were transferred to SW (up to 16-fold in eel and 90-fold in tilapia). Although up-regulation of IMPA1.1 expression was evident in many tissues in the eel, more substantial increases in IMPA1.1 expression were found in tilapia tissues, where SW acclimation resulted in up to 2,000-fold increases in protein expression, 16-fold increases in enzyme activity and 15-fold increases in tissue inositol contents. Immunohistochemical studies indicated that the tissue and cellular distribution of IMPA1.1 protein differed slightly between eels and tilapia; however, in both species the basal epithelial cell layers within the skin and fin, and the branchial epithelium and interstitial cells within the kidney, exhibited high levels of IMPA1.1 protein expression.
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Affiliation(s)
- Svetlana Kalujnaia
- School of Medicine, University of St. Andrews, St. Andrews, United Kingdom
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Wang X, Hirao H. ONIOM (DFT:MM) Study of the Catalytic Mechanism of myo-Inositol Monophosphatase: Essential Role of Water in Enzyme Catalysis in the Two-Metal Mechanism. J Phys Chem B 2013; 117:833-42. [DOI: 10.1021/jp312483n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Xiaoqing Wang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore
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| | - Hajime Hirao
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore
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