1
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Zong G, Desfougères Y, Portela-Torres P, Kwon YU, Saiardi A, Shears SB, Wang H. Biochemical and structural characterization of an inositol pyrophosphate kinase from a giant virus. EMBO J 2024; 43:462-480. [PMID: 38216735 PMCID: PMC10897400 DOI: 10.1038/s44318-023-00005-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 11/11/2023] [Accepted: 11/15/2023] [Indexed: 01/14/2024] Open
Abstract
Kinases that synthesize inositol phosphates (IPs) and pyrophosphates (PP-IPs) control numerous biological processes in eukaryotic cells. Herein, we extend this cellular signaling repertoire to viruses. We have biochemically and structurally characterized a minimalist inositol phosphate kinase (i.e., TvIPK) encoded by Terrestrivirus, a nucleocytoplasmic large ("giant") DNA virus (NCLDV). We show that TvIPK can synthesize inositol pyrophosphates from a range of scyllo- and myo-IPs, both in vitro and when expressed in yeast cells. We present multiple crystal structures of enzyme/substrate/nucleotide complexes with individual resolutions from 1.95 to 2.6 Å. We find a heart-shaped ligand binding pocket comprising an array of positively charged and flexible side chains, underlying the observed substrate diversity. A crucial arginine residue in a conserved "G-loop" orients the γ-phosphate of ATP to allow substrate pyrophosphorylation. We highlight additional conserved catalytic and architectural features in TvIPK, and support their importance through site-directed mutagenesis. We propose that NCLDV inositol phosphate kinases may have assisted evolution of inositol pyrophosphate signaling, and we discuss the potential biogeochemical significance of TvIPK in soil niches.
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Affiliation(s)
- Guangning Zong
- Inositol Signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Yann Desfougères
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Paloma Portela-Torres
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Yong-Uk Kwon
- Department of Chemistry and Nanoscience, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760, South Korea
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK.
| | - Stephen B Shears
- Inositol Signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
| | - Huanchen Wang
- Inositol Signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA.
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2
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Li X, Wei Q, Zhao K, Wang W, Liu B, Li W, Wang J. Monitoring Intracellular IP6 with a Genetically Encoded Fluorescence Biosensor. ACS Sens 2023; 8:4484-4493. [PMID: 38079595 DOI: 10.1021/acssensors.3c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Inositol hexakisphosphate (IP6), a naturally occurring metabolite of inositol with specific functions in different organelles or tissues, participates in numerous physiological processes and plays a key role in mammalian metabolic regulation. However, current IP6 detection methods, i.e., high-performance liquid chromatography and gel electrophoresis, require sample destruction and lack spatiotemporal resolution. Here, we construct and characterize a genetically encoded fluorescence biosensor named HIPSer that enables ratiometric quantitative IP6 detection in HEK293T cells and subcellular compartments. We demonstrate that HIPSer has a high sensitivity and relative selectivity for IP6 in vitro. We also provide proof-of-concept evidence that HIPSer can monitor IP6 levels in real time in HEK293T cells and can be targeted for IP6 detection in the nucleus of HEK293T cells. Moreover, HIPSer could also detect changes in IP6 content induced by chemical inhibition of IP6-metabolizing enzymes in HEK293T cells. Thus, HIPSer achieves spatiotemporally precise detection of fluctuations in endogenous IP6 in live cells and provides a versatile tool for mechanistic investigations of inositol phosphate functions in metabolism and signaling.
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Affiliation(s)
- Xi Li
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Qingpeng Wei
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Kaiyuan Zhao
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Weibo Wang
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Bingjie Liu
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Wenzhe Li
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Jing Wang
- State Key Laboratory of Natural and Biomimetic Drugs and Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
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3
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Hostachy S, Wang H, Zong G, Franke K, Riley AM, Schmieder P, Potter BVL, Shears SB, Fiedler D. Fluorination Influences the Bioisostery of Myo-Inositol Pyrophosphate Analogs. Chemistry 2023; 29:e202302426. [PMID: 37773020 PMCID: PMC7615343 DOI: 10.1002/chem.202302426] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/14/2023] [Accepted: 09/28/2023] [Indexed: 09/30/2023]
Abstract
Inositol pyrophosphates (PP-IPs) are densely phosphorylated messenger molecules involved in numerous biological processes. PP-IPs contain one or two pyrophosphate group(s) attached to a phosphorylated myo-inositol ring. 5PP-IP5 is the most abundant PP-IP in human cells. To investigate the function and regulation by PP-IPs in biological contexts, metabolically stable analogs have been developed. Here, we report the synthesis of a new fluorinated phosphoramidite reagent and its application for the synthesis of a difluoromethylene bisphosphonate analog of 5PP-IP5 . Subsequently, the properties of all currently reported analogs were benchmarked using a number of biophysical and biochemical methods, including co-crystallization, ITC, kinase activity assays and chromatography. Together, the results showcase how small structural alterations of the analogs can have notable effects on their properties in a biochemical setting and will guide in the choice of the most suitable analog(s) for future investigations.
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Affiliation(s)
- Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Rössle-Straße 1013125BerlinGermany
| | - Huanchen Wang
- Inositol Signaling GroupNational Institutes of HealthResearch Triangle ParkNorth Carolina27709USA
| | - Guangning Zong
- Inositol Signaling GroupNational Institutes of HealthResearch Triangle ParkNorth Carolina27709USA
| | - Katy Franke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Rössle-Straße 1013125BerlinGermany
| | - Andrew M. Riley
- Medicinal Chemistry & Drug Discovery Department of PharmacologyUniversity of OxfordOxfordOX1 3QTUK
| | - Peter Schmieder
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Rössle-Straße 1013125BerlinGermany
| | - Barry V. L. Potter
- Medicinal Chemistry & Drug Discovery Department of PharmacologyUniversity of OxfordOxfordOX1 3QTUK
| | - Stephen B. Shears
- Inositol Signaling GroupNational Institutes of HealthResearch Triangle ParkNorth Carolina27709USA
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Rössle-Straße 1013125BerlinGermany
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Str. 212489BerlinGermany
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4
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Abstract
Several studies have identified specific signalling functions for inositol polyphosphates (IPs) in different cell types and have led to the accumulation of new information regarding their cellular roles as well as new insights into their cellular production. These studies have revealed that interaction of IPs with several proteins is critical for stabilization of protein complexes and for modulation of enzymatic activity. This has not only revealed their importance in regulation of several cellular processes but it has also highlighted the possibility of new pharmacological interventions in multiple diseases, including cancer. In this review, we describe some of the intracellular roles of IPs and we discuss the pharmacological opportunities that modulation of IPs levels can provide.
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Affiliation(s)
- Tania Maffucci
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
- Correspondence: (T.M.); (M.F.); Tel.: +61-08-92669712 (M.F.)
| | - Marco Falasca
- School of Pharmacy and Biomedical Sciences, CHIRI, Curtin University, Perth 6102, Australia
- Correspondence: (T.M.); (M.F.); Tel.: +61-08-92669712 (M.F.)
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5
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Schantl AE, Verhulst A, Neven E, Behets GJ, D'Haese PC, Maillard M, Mordasini D, Phan O, Burnier M, Spaggiari D, Decosterd LA, MacAskill MG, Alcaide-Corral CJ, Tavares AAS, Newby DE, Beindl VC, Maj R, Labarre A, Hegde C, Castagner B, Ivarsson ME, Leroux JC. Inhibition of vascular calcification by inositol phosphates derivatized with ethylene glycol oligomers. Nat Commun 2020; 11:721. [PMID: 32024848 PMCID: PMC7002685 DOI: 10.1038/s41467-019-14091-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022] Open
Abstract
Myo-inositol hexakisphosphate (IP6) is a natural product known to inhibit vascular calcification (VC), but with limited potency and low plasma exposure following bolus administration. Here we report the design of a series of inositol phosphate analogs as crystallization inhibitors, among which 4,6-di-O-(methoxy-diethyleneglycol)-myo-inositol-1,2,3,5-tetrakis(phosphate), (OEG2)2-IP4, displays increased in vitro activity, as well as more favorable pharmacokinetic and safety profiles than IP6 after subcutaneous injection. (OEG2)2-IP4 potently stabilizes calciprotein particle (CPP) growth, consistently demonstrates low micromolar activity in different in vitro models of VC (i.e., human serum, primary cell cultures, and tissue explants), and largely abolishes the development of VC in rodent models, while not causing toxicity related to serum calcium chelation. The data suggest a mechanism of action independent of the etiology of VC, whereby (OEG2)2-IP4 disrupts the nucleation and growth of pathological calcification.
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Affiliation(s)
- Antonia E Schantl
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Anja Verhulst
- Laboratory of Pathophysiology, University of Antwerp, Antwerp, Belgium
| | - Ellen Neven
- Laboratory of Pathophysiology, University of Antwerp, Antwerp, Belgium
| | - Geert J Behets
- Laboratory of Pathophysiology, University of Antwerp, Antwerp, Belgium
| | - Patrick C D'Haese
- Laboratory of Pathophysiology, University of Antwerp, Antwerp, Belgium
| | - Marc Maillard
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
| | - David Mordasini
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
| | - Olivier Phan
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
| | - Dany Spaggiari
- Division of Clinical Pharmacology, Lausanne University Hospital, Lausanne, Switzerland
| | - Laurent A Decosterd
- Division of Clinical Pharmacology, Lausanne University Hospital, Lausanne, Switzerland
| | - Mark G MacAskill
- University-BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Carlos J Alcaide-Corral
- University-BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Adriana A S Tavares
- University-BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - David E Newby
- University-BHF Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Victoria C Beindl
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | | | - Anne Labarre
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada
| | - Chrismita Hegde
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada
| | - Bastien Castagner
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Canada
| | | | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.
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6
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Duliński R, Zdaniewicz M, Pater A, Poniewska D, Żyła K. The Impact of Phytases on the Release of Bioactive Inositols, the Profile of Inositol Phosphates, and the Release of Selected Minerals in the Technology of Buckwheat Beer Production. Biomolecules 2020; 10:biom10020166. [PMID: 31973207 PMCID: PMC7072348 DOI: 10.3390/biom10020166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/17/2020] [Accepted: 01/18/2020] [Indexed: 01/01/2023] Open
Abstract
A relatively high concentration of phytate in buckwheat malt, and the low activity of endogenous buckwheat phytases, both of which limit the effective use of substrates (starch, proteins, minerals) for fermentation and yeast metabolism, gives rise to the potential for application of phytases in beer production. This study aims at obtaining a 100% buckwheat wort with high bioactive cyclitols (myo-inositol and D-chiro-inositol) concentrations released by exogenous phytases and acid phosphatases. Two mashing programs were used in the study, i.e., (1) typical for basic raw materials, namely the well-established Congress method, and (2) optimized for phytase activity. The results indicated a nearly 50% increase in the level of bioactive myo-inositol and an 80% degradation of phytate in the wort as a result of simultaneous application of phytase and phosphatase enzymes in the mashing of buckwheat malt. In addition, high D-chiro-inositol concentrations were released from malt to the buckwheat wort. The concerted action of the two phytases significantly increased (19–44%) Zn2+ concentrations in wort. This may be of great importance during mash fermentation by Saccharomyces cerevisiae yeasts. There is a potential to develop technology for buckwheat beer production, which, in addition to being free from gluten, comprises high levels of bioactive myo- and D-chiro-inositols.
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Affiliation(s)
- Robert Duliński
- Department of Biotechnology and General Technology of Food, Faculty of Food Technology, Agricultural University in Krakow, Balicka 122, 30-149 Krakow, Poland; (D.P.)
- Correspondence: ; Tel.: +48-12-6624796; Fax: +48-12-6624795
| | - Marek Zdaniewicz
- Department of Fermentation Technology and Microbiology, Faculty of Food Technology, Agricultural University in Krakow, Balicka 122, 30-149 Krakow, Poland; (M.Z.); (A.P.)
| | - Aneta Pater
- Department of Fermentation Technology and Microbiology, Faculty of Food Technology, Agricultural University in Krakow, Balicka 122, 30-149 Krakow, Poland; (M.Z.); (A.P.)
| | - Dagmara Poniewska
- Department of Biotechnology and General Technology of Food, Faculty of Food Technology, Agricultural University in Krakow, Balicka 122, 30-149 Krakow, Poland; (D.P.)
| | - Krzysztof Żyła
- Department of Biotechnology and General Technology of Food, Faculty of Food Technology, Agricultural University in Krakow, Balicka 122, 30-149 Krakow, Poland; (D.P.)
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7
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Lorenzo‐Orts L, Couto D, Hothorn M. Identity and functions of inorganic and inositol polyphosphates in plants. New Phytol 2020; 225:637-652. [PMID: 31423587 PMCID: PMC6973038 DOI: 10.1111/nph.16129] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/22/2019] [Indexed: 05/08/2023]
Abstract
Inorganic polyphosphates (polyPs) and inositol pyrophosphates (PP-InsPs) form important stores of inorganic phosphate and can act as energy metabolites and signaling molecules. Here we review our current understanding of polyP and inositol phosphate (InsP) metabolism and physiology in plants. We outline methods for polyP and InsP detection, discuss the known plant enzymes involved in their synthesis and breakdown, and summarize the potential physiological and signaling functions for these enigmatic molecules in plants.
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Affiliation(s)
- Laura Lorenzo‐Orts
- Structural Plant Biology LaboratoryDepartment of Botany and Plant BiologyUniversity of Geneva30 Quai E. AnsermetGeneva1211Switzerland
| | - Daniel Couto
- Structural Plant Biology LaboratoryDepartment of Botany and Plant BiologyUniversity of Geneva30 Quai E. AnsermetGeneva1211Switzerland
| | - Michael Hothorn
- Structural Plant Biology LaboratoryDepartment of Botany and Plant BiologyUniversity of Geneva30 Quai E. AnsermetGeneva1211Switzerland
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8
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Hirvonen J, Liljavirta J, Saarinen MT, Lehtinen MJ, Ahonen I, Nurminen P. Effect of Phytase on in Vitro Hydrolysis of Phytate and the Formation of myo-Inositol Phosphate Esters in Various Feed Materials. J Agric Food Chem 2019; 67:11396-11402. [PMID: 31537068 DOI: 10.1021/acs.jafc.9b03919] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phytase is commonly used as a feed enzyme in monogastric animals to increase the bioavailability of phytate phosphorus and other nutrients. The accumulation of myo-inositol phosphate intermediates during phytate degradation in various segments of the gastrointestinal tract (GIT) is poorly understood. The aim of this study was to determine the efficacy of Buttiauxella spp. phytase in degrading the phytate in corn, soybean meal, and complete corn-soybean meal diet to myo-inositol phosphate esters (IP1-IP5) and completely dephosphorylated myo-inositol rings using an in vitro model of the poultry upper GIT. Our results show that the phytase hydrolyzes phytate efficiently to small IP esters, whereas the myo-inositol level remains constant between control and phytase treatments. Although the in vitro digestion model does not incorporate all factors that govern phytate hydrolysis, it is a valuable tool for evaluating phytase efficacy at various enzyme doses and with different feed ingredients.
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Affiliation(s)
- Johanna Hirvonen
- DuPont Nutrition & Biosciences, Global Health & Nutrition Science, Danisco Sweeteners Oy , 02460 Kantvik , Finland
| | - Jenni Liljavirta
- DuPont Nutrition & Biosciences, Global Health & Nutrition Science, Danisco Sweeteners Oy , 02460 Kantvik , Finland
| | - Markku T Saarinen
- DuPont Nutrition & Biosciences, Global Health & Nutrition Science, Danisco Sweeteners Oy , 02460 Kantvik , Finland
| | - Markus J Lehtinen
- DuPont Nutrition & Biosciences, Global Health & Nutrition Science, Danisco Sweeteners Oy , 02460 Kantvik , Finland
| | | | - Päivi Nurminen
- DuPont Nutrition & Biosciences, Global Health & Nutrition Science, Danisco Sweeteners Oy , 02460 Kantvik , Finland
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9
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Goßner S, Yuan F, Zhou C, Tan Y, Shu Q, Engel KH. Impact of Cross-Breeding of Low Phytic Acid MIPS1 and IPK1 Soybean ( Glycine max L. Merr.) Mutants on Their Contents of Inositol Phosphate Isomers. J Agric Food Chem 2019; 67:247-257. [PMID: 30541281 DOI: 10.1021/acs.jafc.8b06117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The knowledge on consequences of cross-breeding of induced low phytic acid ( lpa) soybean ( Glycine max L. Merr.) mutants on the contents of phytic acid (InsP6) and lower inositol phosphate isomers (InsP2-InsP5) in the resulting progenies is limited. Therefore, MIPS1 and IPK1 lpa soybean mutants were crossed with wild-type (WT) cultivars or among themselves to generate homozygous lpa and WT progenies and double lpa mutants. The lpa trait of the MIPS1 mutant was not altered by cross-breeding with a WT cultivar; lpa progenies had InsP6 reductions of about 44% compared to WT progenies. IPK1 progenies showed pronounced accumulations of specific InsP3-InsP5 isomers (up to 12.4 mg/g) compared to the progenitor lpa mutant (4.7 mg/g); the extent of InsP6 reduction (43-71%) was depending on the WT crossing parent. Double mutants exhibited the most pronounced InsP6 reductions (up to 87%), accompanied by moderate accumulations of InsP3-InsP5 (2.5 mg/g). Cross-breeding offers the potential to modulate the amounts of both InsP6 and InsP3-InsP5 contents in lpa soybean mutants and thus to improve their nutritional quality.
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Affiliation(s)
- Sophia Goßner
- Chair of General Food Technology , Technical University of Munich , Maximus-von-Imhof-Forum 2 , D-85354 Freising-Weihenstephan , Germany
| | - Fengjie Yuan
- Institute of Crop Science and Nuclear Technology Utilization , Zhejiang Academy of Agricultural Sciences , Hangzhou 310021 , China
| | - Chenguang Zhou
- Chair of General Food Technology , Technical University of Munich , Maximus-von-Imhof-Forum 2 , D-85354 Freising-Weihenstephan , Germany
| | - Yuanyuan Tan
- State Key Laboratory of Rice Biology and Zhejiang Provincial Key Laboratory of Plant Germplasm, Institute of Crop Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Qingyao Shu
- State Key Laboratory of Rice Biology and Zhejiang Provincial Key Laboratory of Plant Germplasm, Institute of Crop Sciences , Zhejiang University , Hangzhou 310058 , China
| | - Karl-Heinz Engel
- Chair of General Food Technology , Technical University of Munich , Maximus-von-Imhof-Forum 2 , D-85354 Freising-Weihenstephan , Germany
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10
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Chakraborty A. The inositol pyrophosphate pathway in health and diseases. Biol Rev Camb Philos Soc 2018; 93:1203-1227. [PMID: 29282838 PMCID: PMC6383672 DOI: 10.1111/brv.12392] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 11/28/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022]
Abstract
Inositol pyrophosphates (IPPs) are present in organisms ranging from plants, slime moulds and fungi to mammals. Distinct classes of kinases generate different forms of energetic diphosphate-containing IPPs from inositol phosphates (IPs). Conversely, polyphosphate phosphohydrolase enzymes dephosphorylate IPPs to regenerate the respective IPs. IPPs and/or their metabolizing enzymes regulate various cell biological processes by modulating many proteins via diverse mechanisms. In the last decade, extensive research has been conducted in mammalian systems, particularly in knockout mouse models of relevant enzymes. Results obtained from these studies suggest impacts of the IPP pathway on organ development, especially of brain and testis. Conversely, deletion of specific enzymes in the pathway protects mice from various diseases such as diet-induced obesity (DIO), type-2 diabetes (T2D), fatty liver, bacterial infection, thromboembolism, cancer metastasis and aging. Furthermore, pharmacological inhibition of the same class of enzymes in mice validates the therapeutic importance of this pathway in cardio-metabolic diseases. This review critically analyses these findings and summarizes the significance of the IPP pathway in mammalian health and diseases. It also evaluates benefits and risks of targeting this pathway in disease therapies. Finally, future directions of mammalian IPP research are discussed.
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Affiliation(s)
- Anutosh Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO 63104, U.S.A
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11
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Greiner R. Activity of Escherichia coli, Aspergillus niger, and Rye Phytase toward Partially Phosphorylated myo-Inositol Phosphates. J Agric Food Chem 2017; 65:9603-9607. [PMID: 29052415 DOI: 10.1021/acs.jafc.7b03897] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Kinetic parameters for the dephosphorylation of sodium phytate and a series of partially phosphorylated myo-inositol phosphates were determined at pH 3.0 and pH 5.0 for three phytase preparations (Aspergillus niger, Escherichia coli, rye). The enzymes showed lower affinity and turnover numbers at pH 3 compared to pH 5 toward all myo-inositol phosphates included in the study. The number and distribution of phosphate groups on the myo-inositol ring affected the kinetic parameters. Representatives of the individual phytate dephosphorylation pathways were identified as the best substrates of the phytases. Within the individual phytate dephosphorylation pathways, the pentakisphosphates were better substrates compared to the tetrakisphosphates or phytate itself. E. coli and rye phytase showed comparable activities at both pH values toward the tetrakis- and trisphosphate, whereas A. niger phytase exhibited a higher activity toward the tetrakisphosphate. A myo-inositol phosphate with alternate phosphate groups was shown to be not significantly dephosphorylated by the phytases.
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Affiliation(s)
- Ralf Greiner
- Federal Research Institute of Nutrition and Food, Department of Food Technology and Bioprocess Engineering, Max Rubner-Institut , Haid-und-Neu-Straße 9, 76131 Karlsruhe, Germany
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12
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Sommerfeld V, Schollenberger M, Hemberle L, Rodehutscord M. Modification and application of an in vitro assay to examine inositol phosphate degradation in the digestive tract of poultry. J Sci Food Agric 2017; 97:4219-4226. [PMID: 28247412 DOI: 10.1002/jsfa.8297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/16/2017] [Accepted: 02/23/2017] [Indexed: 06/06/2023]
Abstract
BACKGROUND An in vitro assay was modified to study the disappearance of inositol hexakisphosphate (InsP6 ) and the formation of lower inositol phosphate (InsP) isomers in the poultry digestive tract, and three experiments investigated the influence of diets with different ingredients and additives. Using the poultry diet as a matrix, the assay simulated the conditions (e.g. pH, temperature, proteolytic enzymes, water content, and retention time) of the crop, stomach, and small intestine, and extraction and analysis of InsP isomers were immediately conducted. RESULTS The assay produced highly reproducible results with coefficients of variation ≤10% for an InsP isomer concentration ≥0.4 µmol g-1 DM (n = 3), and it was sensitive to the factors that varied in the three experiments. CONCLUSION The described assay is a suitable tool that can be used to screen feed enzymes and to investigate the effects of supplements in the absence of endogenous phytases. The ease of handling and high reproducibility of the assay indicated that the assay is a rapid and feasible method that can be used to examine the degradation pathway of phytate in feed under gastrointestinal conditions. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Vera Sommerfeld
- Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany
| | | | - Luca Hemberle
- Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany
| | - Markus Rodehutscord
- Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany
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13
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Riley AM, Wang H, Shears SB, L. Potter BV. Synthetic tools for studying the chemical biology of InsP8. Chem Commun (Camb) 2015; 51:12605-8. [PMID: 26153667 PMCID: PMC4643724 DOI: 10.1039/c5cc05017k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 07/03/2015] [Indexed: 12/28/2022]
Abstract
To synthesise stabilised mimics of InsP8, the most phosphorylated inositol phosphate signalling molecule in Nature, we replaced its two diphosphate (PP) groups with either phosphonoacetate (PA) or methylenebisphosphonate (PCP) groups. Utility of the PA and PCP analogues was verified by structural and biochemical analyses of their interactions with enzymes of InsP8 metabolism.
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Affiliation(s)
- Andrew M. Riley
- Wolfson Laboratory of Medicinal Chemistry , Department of Pharmacy and Pharmacology , University of Bath , Claverton Down , Bath , BA2 7AY , UK
| | - Huanchen Wang
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Stephen B. Shears
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Barry V. L. Potter
- Wolfson Laboratory of Medicinal Chemistry , Department of Pharmacy and Pharmacology , University of Bath , Claverton Down , Bath , BA2 7AY , UK
- Department of Pharmacology , University of Oxford , Mansfield Road , Oxford , OX1 3QT , UK . ; Fax: +44-1865-271853 ; Tel: +44-1865-271945
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14
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Xi X, Tatei K, Kihara Y, Izumi T. Expression pattern of class I phosphoinositide 3-kinase and distribution of its product, phosphatidylinositol-3,4,5-trisphosphate, during Drosophila embryogenesis. Gene Expr Patterns 2014; 15:88-95. [PMID: 24928809 DOI: 10.1016/j.gep.2014.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 05/27/2014] [Accepted: 06/02/2014] [Indexed: 11/17/2022]
Abstract
The class I phosphoinositide 3-kinase (PI3K) can be activated by a large variety of extracellular stimuli and is responsible for generating phosphatidylinositol-3,4,5-trisphosphate (PI(3,4,5)P(3)) from phosphatidylinositol-4,5-bisphosphate at the plasma membrane. The expression pattern of the class I PI3K and distribution of PI(3,4,5)P(3), visualized by its specific binding protein, GRP1-PH, were examined during Drosophila embryogenesis. We found that the RNA of Pi3K21B, encoding the Drosophila p60 regulatory subunit of the class I PI3Ks, was expressed maternally and expressed primarily in pole cells after cellularization until completion of germ band elongation. The RNA of Pi3K92E, encoding the Drosophila p110 catalytic subunit of the class I PI3Ks, was also expressed maternally. During gastrulation, its transcript level became lower and was slightly enriched in invaginating cells. Both Pi3K21B and Pi3K92E were expressed ubiquitously after germ band elongation and persisted during germ band shortening. PI(3,4,5)P(3) was distributed at the apical region of the invaginating cells during gastrulation. These findings suggest a possible involvement of class I PI3K and PI(3,4,5)P(3) in the regulation of invagination during gastrulation.
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Affiliation(s)
- Xin Xi
- Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Kazuaki Tatei
- Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Yumiko Kihara
- Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
| | - Takashi Izumi
- Department of Biochemistry, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
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15
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Trésaugues L, Silvander C, Flodin S, Welin M, Nyman T, Gräslund S, Hammarström M, Berglund H, Nordlund P. Structural basis for phosphoinositide substrate recognition, catalysis, and membrane interactions in human inositol polyphosphate 5-phosphatases. Structure 2014; 22:744-55. [PMID: 24704254 DOI: 10.1016/j.str.2014.01.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/24/2014] [Accepted: 01/24/2014] [Indexed: 11/15/2022]
Abstract
SHIP2, OCRL, and INPP5B belong to inositol polyphosphate 5-phophatase subfamilies involved in insulin regulation and Lowes syndrome. The structural basis for membrane recognition, substrate specificity, and regulation of inositol polyphosphate 5-phophatases is still poorly understood. We determined the crystal structures of human SHIP2, OCRL, and INPP5B, the latter in complex with phosphoinositide substrate analogs, which revealed a membrane interaction patch likely to assist in sequestering substrates from the lipid bilayer. Residues recognizing the 1-phosphate of the substrates are highly conserved among human family members, suggesting similar substrate binding modes. However, 3- and 4-phosphate recognition varies and determines individual substrate specificity profiles. The high conservation of the environment of the scissile 5-phosphate suggests a common reaction geometry for all members of the human 5-phosphatase family.
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Affiliation(s)
- Lionel Trésaugues
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Camilla Silvander
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden.
| | - Susanne Flodin
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Martin Welin
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Tomas Nyman
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Susanne Gräslund
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Martin Hammarström
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Helena Berglund
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Pär Nordlund
- Structural Genomics Consortium, Karolinska Institutet, 17177 Stockholm, Sweden; Division of Biophysics, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden; Centre for Biomedical Structural Biology, School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
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16
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De Luca AC, Reader-Harris P, Mazilu M, Mariggiò S, Corda D, Di Falco A. Reproducible surface-enhanced Raman quantification of biomarkers in multicomponent mixtures. ACS Nano 2014; 8:2575-2583. [PMID: 24524333 DOI: 10.1021/nn406200y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Direct and quantitative detection of unlabeled glycerophosphoinositol (GroPIns), an abundant cytosolic phosphoinositide derivative, would allow rapid evaluation of several malignant cell transformations. Here we report label-free analysis of GroPIns via surface-enhanced Raman spectroscopy (SERS) with a sensitivity of 200 nM, well below its apparent concentration in cells. Crucially, our SERS substrates, based on lithographically defined gold nanofeatures, can be used to predict accurately the GroPIns concentration even in multicomponent mixtures, avoiding the preliminary separation of individual compounds. Our results represent a critical step toward the creation of SERS-based biosensor for rapid, label-free, and reproducible detection of specific molecules, overcoming limits of current experimental methods.
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Affiliation(s)
- Anna Chiara De Luca
- Institute of Protein Biochemistry, National Research Council , Via P. Castellino 111, 80131 Naples, Italy
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17
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Arrar M, de Oliveira CAF, Andrew McCammon J. Inactivating mutation in histone deacetylase 3 stabilizes its active conformation. Protein Sci 2013; 22:1306-12. [PMID: 23904210 PMCID: PMC3795489 DOI: 10.1002/pro.2317] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 07/12/2013] [Indexed: 12/11/2022]
Abstract
Histone deacetylases (HDACs), together with histone acetyltransferases (HATs), regulate gene expression by modulating the acetylation level of chromatin. HDAC3 is implicated in many important cellular processes, particularly in cancer cell proliferation and metastasis, making inhibition of HDAC3 a promising epigenetic treatment for certain cancers. HDAC3 is activated upon complex formation with both inositol tetraphosphate (IP4) and the deacetylase-activating domain (DAD) of multi-protein nuclear receptor corepressor complexes. In previous studies, we have shown that binding of DAD and IP4 to HDAC3 significantly restricts its conformational space towards its stable ternary complex conformation, and suggest this to be the active conformation. Here, we report a single mutation of HDAC3 that is capable of mimicking the stabilizing effects of DAD and IP4, without the presence of either. This mutation, however, results in a total loss of deacetylase activity, prompting a closer evaluation of our understanding of the activation of HDAC3.
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Affiliation(s)
- Mehrnoosh Arrar
- Department of Chemistry and Biochemistry, University of California San DiegoLa Jolla, California, 92093-0365
| | - Cesar Augusto F de Oliveira
- Department of Chemistry and Biochemistry, University of California San DiegoLa Jolla, California, 92093-0365
- Howard Hughes Medical Institute, University of California San DiegoLa Jolla, California, 92093-0365
| | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California San DiegoLa Jolla, California, 92093-0365
- Howard Hughes Medical Institute, University of California San DiegoLa Jolla, California, 92093-0365
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18
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Millard C, Watson P, Celardo I, Gordiyenko Y, Cowley S, Robinson C, Fairall L, Schwabe J. Class I HDACs share a common mechanism of regulation by inositol phosphates. Mol Cell 2013; 51:57-67. [PMID: 23791785 PMCID: PMC3710971 DOI: 10.1016/j.molcel.2013.05.020] [Citation(s) in RCA: 268] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 04/23/2013] [Accepted: 05/16/2013] [Indexed: 01/06/2023]
Abstract
Class I histone deacetylases (HDAC1, HDAC2, and HDAC3) are recruited by cognate corepressor proteins into specific transcriptional repression complexes that target HDAC activity to chromatin resulting in chromatin condensation and transcriptional silencing. We previously reported the structure of HDAC3 in complex with the SMRT corepressor. This structure revealed the presence of inositol-tetraphosphate [Ins(1,4,5,6)P4] at the interface of the two proteins. It was previously unclear whether the role of Ins(1,4,5,6)P4 is to act as a structural cofactor or a regulator of HDAC3 activity. Here we report the structure of HDAC1 in complex with MTA1 from the NuRD complex. The ELM2-SANT domains from MTA1 wrap completely around HDAC1 occupying both sides of the active site such that the adjacent BAH domain is ideally positioned to recruit nucleosomes to the active site of the enzyme. Functional assays of both the HDAC1 and HDAC3 complexes reveal that Ins(1,4,5,6)P4 is a bona fide conserved regulator of class I HDAC complexes.
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Affiliation(s)
- Christopher J. Millard
- Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK
| | - Peter J. Watson
- Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK
| | - Ivana Celardo
- Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK
| | - Yuliya Gordiyenko
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Shaun M. Cowley
- Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK
| | - Carol V. Robinson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Louise Fairall
- Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK
| | - John W.R. Schwabe
- Henry Wellcome Laboratories of Structural Biology, Department of Biochemistry, University of Leicester, Leicester, LE1 9HN, UK
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19
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Konishi T, Takahashi S, Zhuang Z, Nagata K, Mizumoto M, Honda M, Takeuchi Y, Matsunari H, Nagashima H, Aizawa M. Biodegradable β-tricalcium phosphate cement with anti-washout property based on chelate-setting mechanism of inositol phosphate. J Mater Sci Mater Med 2013; 24:1383-1394. [PMID: 23471502 DOI: 10.1007/s10856-013-4903-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 02/26/2013] [Indexed: 06/01/2023]
Abstract
Novel biodegradable β-tricalcium phosphate (β-TCP) cements with anti-washout properties were created on the basis of chelate-setting mechanism of inositol phosphate (IP6) using β-TCP powders. The β-TCP powders were ball-milled using ZrO₂ beads for 0-6 h in the IP6 solutions with concentrations from 0 to 10,000 ppm. The chelate-setting β-TCP cement with anti-washout property was successfully fabricated by mixing the β-TCP powder ball-milled in 3,000 ppm IP6 solution for 3 h and 2.5 mass% Na₂HPO₄ solution, and compressive strength of the cement was 13.4 ± 0.8 MPa. An in vivo study revealed that the above cement was directly in contact with host and newly formed bones without fibrous tissue layers, and was resorbed by osteoclast-like cells on the surface of the cement. The chelate-setting β-TCP cement with anti-washout property is promising for application as a novel injectable artificial bone with both biodegradability and osteoconductivity.
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Affiliation(s)
- Toshiisa Konishi
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki 214-8571, Japan.
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20
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Skippen A, Swigart P, Cockcroft S. Measurement of phospholipase C by monitoring inositol phosphates using [³H]inositol labeling protocols in permeabilized cells. Methods Mol Biol 2013; 937:163-174. [PMID: 23007585 DOI: 10.1007/978-1-62703-086-1_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Data on the production of inositol phosphates is a useful complement to measurements of intracellular Ca(2+). The basic principle is labeling of the inositol lipids by growing the appropriate cell line in culture in the presence of [3H]inositol for 2-3 days to reach labeling equilibrium. Lithium ions at 10 mM inhibits the degradation of inositol phosphates to free inositol and is used to trap the inositol in the inositol polyphosphate forms. Inositol phosphates can be separated with ease from free inositol by using anion exchange chromatography. A method capable of easily processing approximately 40-60 samples in a single day is presented.
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Affiliation(s)
- Alison Skippen
- Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
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21
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Smart D. Measurement of inositol(1,4,5)trisphosphate using a stereospecific radioreceptor mass assay. Methods Mol Biol 2013; 937:193-203. [PMID: 23007587 DOI: 10.1007/978-1-62703-086-1_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Inositol(1,4,5)trisphosphate [Ins(1,4,5)P(3)] is an important second messenger that activates its cognate Ins(1,4,5)P(3) receptor to release Ca(2+) from intracellular stores. The assay described in this chapter uses the Ins(1,4,5)P(3) receptor (essentially as a binding protein) to measure the biologically active trisphosphate (specifically from other trisphosphates). The binding protein (Ins(1,4,5)P3 receptor) is prepared from Bovine adrenal glands and this is mixed with [(3)H]-labeled and unlabeled (generated from biological samples or standards) Ins(1,4,5)P(3). Using the same principles as for radioimmunoassay/ELISA the mass of Ins(1,4,5)P(3) in biological samples can be estimated.
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Affiliation(s)
- Darren Smart
- Neurology CEDD, GlaxoSmithKline Pharmaceuticals Ltd., Harlow, Essex, UK
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22
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Bunney T, Esposito D, Mas-Droux C, Lamber E, Baxendale R, Martins M, Cole A, Svergun D, Driscoll P, Katan M. Structural and functional integration of the PLCγ interaction domains critical for regulatory mechanisms and signaling deregulation. Structure 2012; 20:2062-75. [PMID: 23063561 PMCID: PMC3532599 DOI: 10.1016/j.str.2012.09.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/03/2012] [Accepted: 09/07/2012] [Indexed: 11/30/2022]
Abstract
Multidomain proteins incorporating interaction domains are central to regulation of cellular processes. The elucidation of structural organization and mechanistic insights into many of these proteins, however, remain challenging due to their inherent flexibility. Here, we describe the organization and function of four interaction domains in PLCγ1 using a combination of structural biology and biochemical approaches. Intramolecular interactions within the regulatory region center on the cSH2 domain, the only domain that also interacts with the PLC-core. In the context of fibroblast growth-factor receptor signaling, the coordinated involvement of nSH2 and cSH2 domains mediates efficient phosphorylation of PLCγ1 resulting in the interruption of an autoinhibitory interface by direct competition and, independently, dissociation of PLCγ1 from the receptor. Further structural insights into the autoinhibitory surfaces provide a framework to interpret gain-of-function mutations in PLCγ isoforms linked to immune disorders and illustrate a distinct mechanism for regulation of PLC activity by common interaction domains.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Substitution
- Animals
- Catalytic Domain
- Cell Line
- Crystallography, X-Ray
- Enzyme Activation
- Humans
- Inositol Phosphates/chemistry
- Kinetics
- Models, Molecular
- Mutagenesis, Site-Directed
- Nuclear Magnetic Resonance, Biomolecular
- Phospholipase C gamma/chemistry
- Phospholipase C gamma/genetics
- Phospholipase C gamma/metabolism
- Phosphorylation
- Protein Binding
- Protein Interaction Domains and Motifs
- Protein Processing, Post-Translational
- Protein Structure, Secondary
- Receptor, Fibroblast Growth Factor, Type 1/metabolism
- Receptor, Fibroblast Growth Factor, Type 1/physiology
- Signal Transduction
- Sus scrofa
- Thermodynamics
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Affiliation(s)
- Tom D. Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Diego Esposito
- Division of Molecular Structure, MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Corine Mas-Droux
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Ekatarina Lamber
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, 1030 Vienna, Austria
| | - Rhona W. Baxendale
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Marta Martins
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | | | - Dmitri Svergun
- European Molecular Biology Laboratory, Hamburg Outstation c/o DESY, Notkestrasse 85, 22603 Hamburg, Germany
| | - Paul C. Driscoll
- Division of Molecular Structure, MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
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23
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Riley AM, Wang H, Weaver JD, Shears SB, Potter BVL. First synthetic analogues of diphosphoinositol polyphosphates: interaction with PP-InsP5 kinase. Chem Commun (Camb) 2012; 48:11292-4. [PMID: 23032903 PMCID: PMC3923271 DOI: 10.1039/c2cc36044f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 09/14/2012] [Indexed: 12/27/2022]
Abstract
We synthesised analogues of diphosphoinositol polyphosphates (PP-InsPs) in which the diphosphate is replaced by an α-phosphonoacetic acid (PA) ester. Structural analysis revealed that 5-PA-InsP(5) mimics 5-PP-InsP(5) binding to the kinase domain of PPIP5K2; both molecules were phosphorylated by the enzyme. PA-InsPs are promising candidates for further studies into the biology of PP-InsPs.
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Affiliation(s)
- Andrew M. Riley
- Wolfson Laboratory of Medicinal Chemistry , Department of Pharmacy and Pharmacology , University of Bath , BA2 7AY , UK . ; Fax: +44 (0)1225 386114 ; Tel: +44 (0)1225 386639
| | - Huanchen Wang
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Jeremy D. Weaver
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Stephen B. Shears
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Barry V. L. Potter
- Wolfson Laboratory of Medicinal Chemistry , Department of Pharmacy and Pharmacology , University of Bath , BA2 7AY , UK . ; Fax: +44 (0)1225 386114 ; Tel: +44 (0)1225 386639
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24
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Singh N, Halliday AC, Knight M, Lack NA, Lowe E, Churchill GC. Cloning, expression, purification, crystallization and X-ray analysis of inositol monophosphatase from Mus musculus and Homo sapiens. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1149-52. [PMID: 23027737 PMCID: PMC3497969 DOI: 10.1107/s1744309112035191] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/08/2012] [Indexed: 11/10/2022]
Abstract
Inositol monophosphatase (IMPase) catalyses the hydrolysis of inositol monophosphate to inositol and is crucial in the phosphatidylinositol (PI) signalling pathway. Lithium, which is the drug of choice for bipolar disorder, inhibits IMPase at therapeutically relevant plasma concentrations. Both mouse IMPase 1 (MmIMPase 1) and human IMPase 1 (HsIMPase 1) were cloned into pRSET5a, expressed in Escherichia coli, purified and crystallized using the sitting-drop method. The structures were solved at resolutions of 2.4 and 1.7 Å, respectively. Comparison of MmIMPase 1 and HsIMPase 1 revealed a core r.m.s. deviation of 0.516 Å.
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Affiliation(s)
- Nisha Singh
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, England
| | - Amy C. Halliday
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, England
| | - Matthew Knight
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, England
| | - Nathan A. Lack
- Koç University School of Medicine, Rumelifeneri Yolu, Sarıyer, Istanbul, Turkey
| | - Edward Lowe
- Biochemistry Department, University of Oxford, Oxford OX1 3QU, England
| | - Grant C. Churchill
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, England
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25
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Abstract
Inositol serves as a module for the generation of a high level of molecular diversity through the combinatorial attachment and removal of phosphate groups. The array of potential inositol-containing molecules is further expanded by the generation of diphospho inositol polyphosphates, commonly referred as inositol pyrophosphates. All eukaryotic cells possess inositol pyrophosphates containing one or more diphospho- moieties. The metabolism of this class of molecules is highly dynamic, and the enzymes responsible for their metabolism are evolutionary conserved. This new, exciting class of molecules are uniquely chracterized by a high energetic diphospho- bound that is able to participate in phosphotrasfer reactions thereby generating pyrophosphorylation of protein. However, allosteric mechanisms of action have been also proposed. In the past decade several disparate nuclear and cytoplasmic functions have been attributed to inositol pyrophosphates, ranging from intracellular trafficking to telomere length control and from regulating apoptotic process to stimulating insulin secretion. The extraordinary range of cellular function controlled by inositol pyrophosphate underline their great importance.
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Affiliation(s)
- Adolfo Saiardi
- MRC-LMCB, Department of Cell and Developmental Biology, University College London, Gower Street, WC1E 6BT, London, UK,
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Kleinau G, Jaeschke H, Worth CL, Mueller S, Gonzalez J, Paschke R, Krause G. Principles and determinants of G-protein coupling by the rhodopsin-like thyrotropin receptor. PLoS One 2010; 5:e9745. [PMID: 20305779 PMCID: PMC2841179 DOI: 10.1371/journal.pone.0009745] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Accepted: 02/19/2010] [Indexed: 11/23/2022] Open
Abstract
In this study we wanted to gain insights into selectivity mechanisms between G-protein-coupled receptors (GPCR) and different subtypes of G-proteins. The thyrotropin receptor (TSHR) binds G-proteins promiscuously and activates both Gs (cAMP) and Gq (IP). Our goal was to dissect selectivity patterns for both pathways in the intracellular region of this receptor. We were particularly interested in the participation of poorly investigated receptor parts. We systematically investigated the amino acids of intracellular loop (ICL) 1 and helix 8 using site-directed mutagenesis alongside characterization of cAMP and IP accumulation. This approach was guided by a homology model of activated TSHR in complex with heterotrimeric Gq, using the X-ray structure of opsin with a bound G-protein peptide as a structural template. We provide evidence that ICL1 is significantly involved in G-protein activation and our model suggests potential interactions with subunits Gα as well as Gβγ. Several amino acid substitutions impaired both IP and cAMP accumulation. Moreover, we found a few residues in ICL1 (L440, T441, H443) and helix 8 (R687) that are sensitive for Gq but not for Gs activation. Conversely, not even one residue was found that selectively affects cAMP accumulation only. Together with our previous mutagenesis data on ICL2 and ICL3 we provide here the first systematically completed map of potential interfaces between TSHR and heterotrimeric G-protein. The TSHR/Gq-heterotrimer complex is characterized by more selective interactions than the TSHR/Gs complex. In fact the receptor interface for binding Gs is a subset of that for Gq and we postulate that this may be true for other GPCRs coupling these G-proteins. Our findings support that G-protein coupling and preference is dominated by specific structural features at the intracellular region of the activated GPCR but is completed by additional complementary recognition patterns between receptor and G-protein subtypes.
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Affiliation(s)
- Gunnar Kleinau
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Holger Jaeschke
- Department for Internal Medicine, Neurology and Dermatology, University of Leipzig, Leipzig, Germany
| | | | - Sandra Mueller
- Department for Internal Medicine, Neurology and Dermatology, University of Leipzig, Leipzig, Germany
| | - Jorge Gonzalez
- Department for Internal Medicine, Neurology and Dermatology, University of Leipzig, Leipzig, Germany
| | - Ralf Paschke
- Department for Internal Medicine, Neurology and Dermatology, University of Leipzig, Leipzig, Germany
| | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
- * E-mail:
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Abstract
A nonradioactive high-performance anion-exchange chromatographic method based on MDD-HPLC (Mayr Biochem. J. 254:585-591, 1988) was developed for the separation of inositol hexakisphosphate (InsP(6), phytic acid) and most isomers of pyrophosphorylated inositol phosphates, such as diphosphoinositol pentakisphosphate (PPInsP(5) or InsP(7)) and bis-diphosphoinositol tetrakisphosphate (bisPPInsP(4) or InsP(8)). With an acidic elution, the anion-exchange separation led to the resolution of four separable PPInsP(5) isomers (including pairs of enantiomers) into three peaks and of nine separable bisPPInsP(4) isomers into nine peaks. The whole separation procedure was completed within 20-36 min after optimization. Reference standards of all bisPPInsP(4) isomers were generated by a nonenzymatic shotgun synthesis from InsP(6). Hereby, the phosphorylation was brought about nonenzymatically when concentrated InsP(6) bound to the solid surface of anion-exchange beads was incubated with creatine phosphate under optimal pH conditions. From the mixture of pyrophosphorylated InsP(6) derivatives containing all theoretically possible isomers of PPInsP(5), bisPPInsP(4), and also some isomers of trisPPInsP(3), isomers were separated by anion-exchange chromatography and fractions served as reference standards of bisPPInsP(4) isomers for further investigation. Their isomeric nature could be partly assigned by comparison with position specifically synthesized or NMR-characterized purified protozoan reference compounds and partly by limited hydrolysis to PPInsP(5) isomers. By applying this nonradioactive analysis technique to cellular studies, the isomeric nature of the major bisPPInsP(4) in mammalian cells could be identified without the need to obtain sufficient material for NMR analysis.
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Affiliation(s)
- Hongying Lin
- Institut für Biochemie und Molekularbiologie I: Zelluläre Signaltransduktion, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
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Barker CJ, Illies C, Gaboardi GC, Berggren PO. Inositol pyrophosphates: structure, enzymology and function. Cell Mol Life Sci 2009; 66:3851-71. [PMID: 19714294 PMCID: PMC11115731 DOI: 10.1007/s00018-009-0115-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/13/2009] [Accepted: 07/20/2009] [Indexed: 02/04/2023]
Abstract
The stereochemistry of the inositol backbone provides a platform on which to generate a vast array of distinct molecular motifs that are used to convey information both in signal transduction and many other critical areas of cell biology. Diphosphoinositol phosphates, or inositol pyrophosphates, are the most recently characterized members of the inositide family. They represent a new frontier with both novel targets within the cell and novel modes of action. This includes the proposed pyrophosphorylation of a unique subset of proteins. We review recent insights into the structures of these molecules and the properties of the enzymes which regulate their concentration. These enzymes also act independently of their catalytic activity via protein-protein interactions. This unique combination of enzymes and products has an important role in diverse cellular processes including vesicle trafficking, endo- and exocytosis, apoptosis, telomere length regulation, chromatin hyperrecombination, the response to osmotic stress, and elements of nucleolar function.
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Affiliation(s)
- Christopher John Barker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, 171 76 Stockholm, Sweden
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Ferreira LT, Dale LB, Ribeiro FM, Babwah AV, Pampillo M, Ferguson SSG. Calcineurin inhibitor protein (CAIN) attenuates Group I metabotropic glutamate receptor endocytosis and signaling. J Biol Chem 2009; 284:28986-94. [PMID: 19717561 PMCID: PMC2781445 DOI: 10.1074/jbc.m109.050872] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Indexed: 11/06/2022] Open
Abstract
Group I metabotropic glutamate receptors (mGluRs) are coupled via phospholipase Cbeta to the hydrolysis of phosphoinositides and function to modulate neuronal excitability and synaptic transmission at glutamatergic synapses. The desensitization of Group I mGluR signaling is thought to be mediated primarily via second messenger-dependent protein kinases and G protein-coupled receptor kinases. We show here that both mGluR1 and mGluR5 interact with the calcineurin inhibitor protein (CAIN). CAIN is co-immunoprecipitated in a complex with Group I mGluRs from both HEK 293 cells and mouse cortical brain lysates. Purified CAIN and its C-terminal domain specifically interact with glutathione S-transferase fusion proteins corresponding to the second intracellular loop and the distal C-terminal tail domains of mGluR1. The interaction of CAIN with mGluR1 could also be blocked using a Tat-tagged peptide corresponding to the mGluR1 second intracellular loop domain. Overexpression of full-length CAIN attenuates the agonist-stimulated endocytosis of both mGluR1a and mGluR5a in HEK 293 cells, but expression of the CAIN C-terminal domain does not alter mGluR5a internalization. In contrast, overexpression of either full-length CAIN or the CAIN C-terminal domain impairs agonist-stimulated inositol phosphate formation in HEK 293 cells expressing mGluR1a. This CAIN-mediated antagonism of mGluR1a signaling appears to involve the disruption of receptor-Galpha(q/11) complexes. Taken together, these observations suggest that the association of CAIN with intracellular domains involved in mGluR/G protein coupling provides an additional mechanism by which Group I mGluR endocytosis and signaling are regulated.
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Affiliation(s)
- Lucimar T. Ferreira
- From the J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, Ontario N6A 5K8 and
| | - Lianne B. Dale
- From the J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, Ontario N6A 5K8 and
| | - Fabiola M. Ribeiro
- From the J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, Ontario N6A 5K8 and
| | - Andy V. Babwah
- From the J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, Ontario N6A 5K8 and
| | - Macarena Pampillo
- From the J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, Ontario N6A 5K8 and
| | - Stephen S. G. Ferguson
- From the J. Allyn Taylor Centre for Cell Biology, Molecular Brain Research Group, Robarts Research Institute, Ontario N6A 5K8 and
- the Department of Physiology and Pharmacology, The University of Western Ontario, Ontario N6A 5C1, Canada
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30
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Wang N, Yang HF, Zhu X, Zhang R, Wang Y, Huang GF, Zhang ZR. Synthesis of anti-aggregation silver nanoparticles based on inositol hexakisphosphoric micelles for a stable surface enhanced Raman scattering substrate. Nanotechnology 2009; 20:315603. [PMID: 19597257 DOI: 10.1088/0957-4484/20/31/315603] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report a novel method of synthesizing a kind of silver nanoparticles aided by the inositol hexakisphosphoric micelle as a soft template and stabilizer. By controlling the reaction time, UV-vis and TEM observations of the size growth of the nanoparticles are performed. Careful examinations of surface enhanced Raman scattering (SERS) spectra of 2-mercaptopyridine (2-Mpy) on the as-produced silver nanoparticles exhibit very stable and reproducible Raman signals within about 4 months.
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Affiliation(s)
- Na Wang
- Department of Chemistry, Shanghai Normal University, Shanghai 200234, People's Republic of China
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31
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Heighton L, Schmidt WF, Siefert RL. Kinetic and equilibrium constants of phytic acid and ferric and ferrous phytate derived from nuclear magnetic resonance spectroscopy. J Agric Food Chem 2008; 56:9543-9547. [PMID: 18798632 DOI: 10.1021/jf801465y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Inositol phosphates are metabolically derived organic phosphates (P) that increasingly appear to be an important sink and source of P in the environment. Salts of myo-inositol hexakisdihydrogen phosphate (IHP) or more commonly phytate are the most common inositol phosphates in the environment. IHP resists acidic dephosphorylation and enzymatic dephosphorylation as ferric or ferrous IHP. Mobility of IHP iron complexes is potentially pH and redox responsive, making the time scale and environmental fate and transport of the P associated with the IHP of interest to the mass balance of phosphorus. Ferric and ferrous complexes of IHP were investigated by proton nuclear magnetic resonance spectroscopy ( (1)H NMR) and enzymatic dephosphorylation. Ferrous IHP was found to form quickly and persist for a longer period then ferric IHP. Dissociation constants derived from (1)H NMR experiments of chemically exchanging systems at equilibrium were 1.11 and 1.19 and formation constants were 0.90 and 0.84 for ferric and ferrous IHP, respectively. The recovery of P from enzymatic dephosphorylation of ferric and ferrous IHP was consistent with the magnitude of the kinetic and equilibrium rate constants.
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Affiliation(s)
- Lynne Heighton
- Chemistry and Biochemistry Department, University of Maryland, College Park, Maryland 20742, USA.
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32
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Vetting MW, Frantom PA, Blanchard JS. Structural and enzymatic analysis of MshA from Corynebacterium glutamicum: substrate-assisted catalysis. J Biol Chem 2008; 283:15834-44. [PMID: 18390549 PMCID: PMC2414306 DOI: 10.1074/jbc.m801017200] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 03/26/2008] [Indexed: 11/06/2022] Open
Abstract
The glycosyltransferase termed MshA catalyzes the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to 1-L-myo-inositol-1-phosphate in the first committed step of mycothiol biosynthesis. The structure of MshA from Corynebacterium glutamicum was determined both in the absence of substrates and in a complex with UDP and 1-L-myo-inositol-1-phosphate. MshA belongs to the GT-B structural family whose members have a two-domain structure with both domains exhibiting a Rossman-type fold. Binding of the donor sugar to the C-terminal domain produces a 97 degrees rotational reorientation of the N-terminal domain relative to the C-terminal domain, clamping down on UDP and generating the binding site for 1-L-myo-inositol-1-phosphate. The structure highlights the residues important in binding of UDP-N-acetylglucosamine and 1-L-myo-inositol-1-phosphate. Molecular models of the ternary complex suggest a mechanism in which the beta-phosphate of the substrate, UDP-N-acetylglucosamine, promotes the nucleophilic attack of the 3-hydroxyl group of 1-L-myo-inositol-1-phosphate while at the same time promoting the cleavage of the sugar nucleotide bond.
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Affiliation(s)
- Matthew W Vetting
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Kunjara S, McLean P, Greenbaum AL, Rademacher TW. Insight into the role of inositol phosphoglycans in insulin response and the regulation of glucose and lipid metabolism illustrated by the response of adipocytes from two strains of rats. Mol Genet Metab 2008; 94:263-6. [PMID: 18359258 DOI: 10.1016/j.ymgme.2008.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Accepted: 02/12/2008] [Indexed: 11/28/2022]
Abstract
Differences in biochemical and hormone profiles between two strains of rats provide insights into the relationships between insulin response, inositol phosphoglycans and lipid metabolism in adipose tissue. The results suggest the apparent anomaly of a higher rate of lipogenesis and response to insulin with a lower fat pad weight in the Charles River vs. Harlan Olac group relates to: (i) enzyme pre-programming with IPG-A, (ii) faster turnover of lipid, (iii) effects of leptin and cAMP.
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Affiliation(s)
- S Kunjara
- University College London Medical School, Department of Immunology and Molecular Pathology, Molecular Medicine Unit, London W1T 4JF, UK
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34
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Abstract
In this review, I summarize the development over the past several years of fluorescent and/or bioluminescent indicators to pinpoint cellular processes in living cells. These processes involve second messengers, protein phosphorylations, protein-protein interactions, protein-ligand interactions, nuclear receptor-coregulator interactions, nucleocytoplasmic trafficking of functional proteins, and protein localization.
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Bhandari R, Saiardi A, Ahmadibeni Y, Snowman AM, Resnick AC, Kristiansen TZ, Molina H, Pandey A, Werner JK, Juluri KR, Xu Y, Prestwich GD, Parang K, Snyder SH. Protein pyrophosphorylation by inositol pyrophosphates is a posttranslational event. Proc Natl Acad Sci U S A 2007; 104:15305-10. [PMID: 17873058 PMCID: PMC2000531 DOI: 10.1073/pnas.0707338104] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In a previous study, we showed that the inositol pyrophosphate diphosphoinositol pentakisphosphate (IP(7)) physiologically phosphorylates mammalian and yeast proteins. We now report that this phosphate transfer reflects pyrophosphorylation. Thus, proteins must be prephosphorylated by ATP to prime them for IP(7) phosphorylation. IP(7) phosphorylates synthetic phosphopeptides but not if their phosphates have been masked by methylation or pyrophosphorylation. Moreover, IP(7) phosphorylated peptides are more acid-labile and more resistant to phosphatases than ATP phosphorylated peptides, indicating a different type of phosphate bond. Pyrophosphorylation may represent a novel mode of signaling to proteins.
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Affiliation(s)
| | - Adolfo Saiardi
- Medical Research Council (MRC) Cell Biology Unit and Laboratory for Molecular Cell Biology, Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Yousef Ahmadibeni
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881; and
| | | | | | - Troels Z. Kristiansen
- McKusick–Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205
| | - Henrik Molina
- McKusick–Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205
| | - Akhilesh Pandey
- McKusick–Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205
| | | | | | - Yong Xu
- Department of Medicinal Chemistry, University of Utah, 419 Wakara Way,Suite 205, Salt Lake City, UT 84108
| | - Glenn D. Prestwich
- Department of Medicinal Chemistry, University of Utah, 419 Wakara Way,Suite 205, Salt Lake City, UT 84108
| | - Keykavous Parang
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI 02881; and
| | - Solomon H. Snyder
- *The Solomon H. Snyder Department of Neuroscience
- Departments of **Pharmacology and Molecular Sciences
- Psychiatry and Behavioral Sciences, and
- To whom correspondence should be addressed at:
725 North Wolfe Street, WBSB 813, Baltimore, MD 21205. E-mail:
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36
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Abstract
Using a combination of high-performance ion chromatography analysis and kinetic studies, the pathway of myo-inositol hexakisphosphate dephosphorylation by the beta-propeller phytase of Shewanella oneidensis was established, which was then compared with that of Bacillus subtilis 168, Bacillus amyloliquefaciens ATCC 15841, and B. amyloliquefaciens 45 beta-propeller phytases. The data demonstrate that all of these beta-propeller phytases dephosphorylate myo-inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via d-Ins(1,2,4,5,6)P5, Ins(2,4,5,6)P4 to finally Ins(2,4,6)P3. Thus, the beta-propeller phytases prefer the hydrolysis of every second phosphate over that of adjacent ones. This finding does not support previous phytate degradation models proposed by J. Kerovuo, J. Rouvinen, and F. Hatzack (2000. Biochem. J. 352: 623-628) and R. Greiner, A. Farouk, M. Larsson Alminger, and N.G. Carlsson (2002. Can. J. Microbiol. 48: 986-994), but seems to fit with the structural model given by S. Shin, N.C. Ha, B.C. Oh, T.K. Oh, and B.H. Oh (2001. Structure, 9: 851-858).
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Affiliation(s)
- Ralf Greiner
- Centre for Molecular Biology, Federal Research Centre for Nutrition and Food, Haid-und-Neu-Strasse 9, Karlsruhe, Germany.
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Abstract
Noncoding RNAs (ncRNA) participate in epigenetic regulation but are poorly understood. Here we characterize the transcriptional landscape of the four human HOX loci at five base pair resolution in 11 anatomic sites and identify 231 HOX ncRNAs that extend known transcribed regions by more than 30 kilobases. HOX ncRNAs are spatially expressed along developmental axes and possess unique sequence motifs, and their expression demarcates broad chromosomal domains of differential histone methylation and RNA polymerase accessibility. We identified a 2.2 kilobase ncRNA residing in the HOXC locus, termed HOTAIR, which represses transcription in trans across 40 kilobases of the HOXD locus. HOTAIR interacts with Polycomb Repressive Complex 2 (PRC2) and is required for PRC2 occupancy and histone H3 lysine-27 trimethylation of HOXD locus. Thus, transcription of ncRNA may demarcate chromosomal domains of gene silencing at a distance; these results have broad implications for gene regulation in development and disease states.
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Affiliation(s)
- Sara Maria Nancy Onnebo
- Medical Research Council (MRC) Cell Biology Unit and Laboratory for Molecular Cell Biology, Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, UK
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Abstract
Among the many derivatives of the inositol-based signalling family are a subgroup that possess diphosphates. In this review, some recent research into the actions of these specialized polyphosphates is analysed, and key goals for future studies are identified, which, it is hoped, will result in the wider cell-signalling community giving considerably greater attention to this intriguing but relatively neglected class of inositol polyphosphates.
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Affiliation(s)
- Stephen B Shears
- Inositide Signaling Group, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, PO Box 12233, NC 27709, USA.
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Bzymek KP, Newton GL, Ta P, Fahey RC. Mycothiol import by Mycobacterium smegmatis and function as a resource for metabolic precursors and energy production. J Bacteriol 2007; 189:6796-805. [PMID: 17644601 PMCID: PMC2045207 DOI: 10.1128/jb.00644-07] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mycothiol ([MSH] AcCys-GlcN-Ins, where Ac is acetyl) is the major thiol produced by Mycobacterium smegmatis and other actinomycetes. Mutants deficient in MshA (strain 49) or MshC (transposon mutant Tn1) of MSH biosynthesis produce no MSH. However, when stationary phase cultures of these mutants were incubated in medium containing MSH, they actively transported it to generate cellular levels of MSH comparable to or greater than the normal content of the wild-type strain. When these MSH-loaded mutants were transferred to MSH-free preconditioned medium, the cellular MSH was catabolized to generate GlcN-Ins and AcCys. The latter was rapidly converted to Cys by a high deacetylase activity assayed in extracts. The Cys could be converted to pyruvate by a cysteine desulfhydrase or used to regenerate MSH in cells with active MshC. Using MSH labeled with [U-(14)C]cysteine or with [6-(3)H]GlcN, it was shown that these residues are catabolized to generate radiolabeled products that are ultimately lost from the cell, indicating extensive catabolism via the glycolytic and Krebs cycle pathways. These findings, coupled with the fact the myo-inositol can serve as a sole carbon source for growth of M. smegmatis, indicate that MSH functions not only as a protective cofactor but also as a reservoir of readily available biosynthetic precursors and energy-generating metabolites potentially important under stress conditions. The half-life of MSH was determined in stationary phase cells to be approximately 50 h in strains with active MshC and 16 +/- 3 h in the MshC-deficient mutant, suggesting that MSH biosynthesis may be a suitable target for drugs to treat dormant tuberculosis.
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Affiliation(s)
- Krzysztof P Bzymek
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0314, USA
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Egerer M, Giesemann T, Jank T, Satchell KJF, Aktories K. Auto-catalytic cleavage of Clostridium difficile toxins A and B depends on cysteine protease activity. J Biol Chem 2007; 282:25314-21. [PMID: 17591770 DOI: 10.1074/jbc.m703062200] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The action of Clostridium difficile toxins A and B depends on processing and translocation of the catalytic glucosyltransferase domain into the cytosol of target cells where Rho GTPases are modified. Here we studied the processing of the toxins. Dithiothreitol and beta-mercaptoethanol induced auto-cleavage of purified native toxin A and toxin B into approximately 250/210- and approximately 63-kDa fragments. The 63-kDa fragment was identified by mass spectrometric analysis as the N-terminal glucosyltransferase domain. This cleavage was blocked by N-ethylmaleimide or iodoacetamide. Exchange of cysteine 698, histidine 653, or aspartate 587 of toxin B prevented cleavage of full-length recombinant toxin B and of an N-terminal fragment covering residues 1-955 and inhibited cytotoxicity of full-length toxin B. Dithiothreitol synergistically increased the effect of myo-inositol hexakisphosphate, which has been reported to facilitate auto-cleavage of toxin B (Reineke, J., Tenzer, S., Rupnik, M., Koschinski, A., Hasselmayer, O., Schrattenholz, A., Schild, H., and Von Eichel-Streiber, C. (2007) Nature 446, 415-419). N-Ethylmaleimide blocked auto-cleavage induced by the addition of myo-inositol hexakisphosphate, suggesting that cysteine residues are essential for the processing of clostridial glucosylating toxins. Our data indicate that clostridial glucosylating cytotoxins possess an inherent cysteine protease activity related to the cysteine protease of Vibrio cholerae RTX toxin, which is responsible for auto-cleavage of glucosylating toxins.
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Affiliation(s)
- Martina Egerer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität, D-79104 Freiburg, Germany
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41
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Puhl AA, Gruninger RJ, Greiner R, Janzen TW, Mosimann SC, Selinger LB. Kinetic and structural analysis of a bacterial protein tyrosine phosphatase-like myo-inositol polyphosphatase. Protein Sci 2007; 16:1368-78. [PMID: 17567745 PMCID: PMC2206706 DOI: 10.1110/ps.062738307] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PhyA from Selenomonas ruminantium (PhyAsr), is a bacterial protein tyrosine phosphatase (PTP)-like inositol polyphosphate phosphatase (IPPase) that is distantly related to known PTPs. PhyAsr has a second substrate binding site referred to as a standby site and the P-loop (HCX5R) has been observed in both open (inactive) and closed (active) conformations. Site-directed mutagenesis and kinetic and structural studies indicate PhyAsr follows a classical PTP mechanism of hydrolysis and has a broad specificity toward polyphosphorylated myo-inositol substrates, including phosphoinositides. Kinetic and molecular docking experiments demonstrate PhyAsr preferentially cleaves the 3-phosphate position of Ins P6 and will produce Ins(2)P via a highly ordered series of sequential dephosphorylations: D-Ins(1,2,4,5,6)P5, Ins(2,4,5,6)P4, D-Ins(2,4,5)P3, and D-Ins(2,4)P2. The data support a distributive enzyme mechanism and suggest the PhyAsr standby site is involved in the recruitment of substrate. Structural studies at physiological pH and high salt concentrations demonstrate the "closed" or active P-loop conformation can be induced in the absence of substrate. These results suggest PhyAsr should be reclassified as a D-3 myo-inositol hexakisphosphate phosphohydrolase and suggest the PhyAsr reaction mechanism is more similar to that of PTPs than previously suspected.
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Affiliation(s)
- Aaron A Puhl
- Department of Biological Sciences, University of Lethbridge, Alberta, Canada
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Sarkisov DV, Gelber SE, Walker JW, Wang SSH. Synapse specificity of calcium release probed by chemical two-photon uncaging of inositol 1,4,5-trisphosphate. J Biol Chem 2007; 282:25517-26. [PMID: 17540776 DOI: 10.1074/jbc.m609672200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biological messengers can be "caged" by adding a single photosensitive group that can be photolyzed by a light flash to achieve spatially and temporally precise biochemical control. Here we report that photolysis of a double-caged form of the second messenger inositol 1,4,5-trisphosphate (IP3) triggers focal calcium release in Purkinje cell somata, dendrites, and spines as measured by two-photon microscopy. In calbindin knock-out Purkinje cells, peak calcium increased with flash energy with higher cooperativity for double-caged IP3 than for conventional single-caged IP3, consistent with a chemical two-photon effect. Spine photolysis of double-caged IP3 led to local calcium release. Uncaging of glycerophosphoryl-myo-inositol 4,5-bisphosphate (gPIP2), a poorly metabolizable IP3 analog, led to less well localized release. Thus, IP3 breakdown is necessary for spine-specificity. IP3- and gPIP2-evoked signals declined from peak with similar, slow time courses, indicating that release lasts hundreds of milliseconds and is terminated not by IP3 degradation but by intrinsic receptor dynamics. Based on measurements of spine-dendrite coupling, IP3-evoked calcium signals are expected to be at least 2.4-fold larger in their spine of origin than in nearby spines, allowing IP3 to act as a synapse-specific second messenger. Unexpectedly, single-caged IP3 led to less release in somata and was ineffective in dendrites and spines. Calcium release using caged gPIP2 was inhibited by the addition of single-caged IP3, suggesting that single-caged IP3 is an antagonist of calcium release. Caging at multiple sites may be an effective general approach to reducing residual receptor interaction.
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Affiliation(s)
- Dmitry V Sarkisov
- Department of Physics and Molecular Biology and Program in Neuroscience, Princeton University, Princeton, New Jersey 08544, USA
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Wada M, DeLong CJ, Hong YH, Rieke CJ, Song I, Sidhu RS, Yuan C, Warnock M, Schmaier AH, Yokoyama C, Smyth EM, Wilson SJ, FitzGerald GA, Garavito RM, Sui DX, Regan JW, Smith WL. Enzymes and receptors of prostaglandin pathways with arachidonic acid-derived versus eicosapentaenoic acid-derived substrates and products. J Biol Chem 2007; 282:22254-66. [PMID: 17519235 DOI: 10.1074/jbc.m703169200] [Citation(s) in RCA: 282] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Dietary fish oil containing omega 3 highly unsaturated fatty acids has cardioprotective and anti-inflammatory effects. Prostaglandins (PGs) and thromboxanes are produced in vivo both from the omega 6 fatty acid arachidonic acid (AA) and the omega 3 fatty acid eicosapentaenoic acid (EPA). Certain beneficial effects of fish oil may result from altered PG metabolism resulting from increases in the EPA/AA ratios of precursor phospholipids. Here we report in vitro specificities of prostanoid enzymes and receptors toward EPA-derived, 3-series versus AA-derived, 2-series prostanoid substrates and products. The largest difference was seen with PG endoperoxide H synthase (PGHS)-1. Under optimal conditions purified PGHS-1 oxygenates EPA with only 10% of the efficiency of AA, and EPA significantly inhibits AA oxygenation by PGHS-1. Two- to 3-fold higher activities or potencies with 2-series versus 3-series compounds were observed with PGHS-2, PGD synthases, microsomal PGE synthase-1 and EP1, EP2, EP3, and FP receptors. Our most surprising observation was that AA oxygenation by PGHS-2 is only modestly inhibited by EPA (i.e. PGHS-2 exhibits a marked preference for AA when EPA and AA are tested together). Also unexpectedly, TxA(3) is about equipotent to TxA(2) at the TP alpha receptor. Our biochemical data predict that increasing phospholipid EPA/AA ratios in cells would dampen prostanoid signaling with the largest effects being on PGHS-1 pathways involving PGD, PGE, and PGF. Production of 2-series prostanoids from AA by PGHS-2 would be expected to decrease in proportion to the compensatory decrease in the AA content of phospholipids that would result from increased incorporation of omega 3 fatty acids such as EPA.
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Affiliation(s)
- Masayuki Wada
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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Abstract
Physiologic roles of highly phosphorylated inositol phosphates, including those containing pyrophosphate groups, have been the focus of much recent interest. In the April 6, 2007 issue of Science, two papers (Lee et al., 2007; Mulugu et al., 2007) demonstrate the occurrence of a novel inositol pyrophosphate molecule in yeast and elucidate its role in phosphate homeostasis.
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Affiliation(s)
- Rashna Bhandari
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Abstract
This review highlights inositol polyphosphate- and phosphatidylinositol-based small molecule probes that have advanced our understanding of intracellular signalling.
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Affiliation(s)
- Stuart J Conway
- EaStCHEM, School of Chemistry and Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife, UK KY16 9ST
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Yang P, Spiess B, Murthy PPN, Brown RE. Influence of Metal Cations on the Intramolecular Hydrogen-Bonding Network and pKa in Phosphorylated Compounds. J Phys Chem A 2007; 111:3602-12. [PMID: 17432837 DOI: 10.1021/jp068890d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The binding of the most common metal cations of cytoplasm (Li+, Na+, K+, Mg2+ and Ca2+) to a model molecule having an intramolecular hydrogen-bonding network, myo-inositol-2-monophosphate, was studied using first principles. A strong correlation between the conformation of metal inositol phosphate complexes with the type of metal cation, degree of deprotonation state, and the surrounding environment has been observed. On the basis of the hydrogen-bonding network analysis of the cation-phosphate complexes (Mn+-Ins(2)P1), the alkali cations show little effect on the conformational preference while the conformational preference for the binding of the alkaline earth cations is pH-dependent and solvent-dependent. For example, these calculations predict that Mg2+-Ins(2)P1(0) and Mg2+-Ins(2)P1(2-) favor the 1a/5e form while Mg2+-Ins(2)P1(1-) favors the 5a/1e conformation. The Ca2+-Ins(2)P1(2-) complex prefers the 1a/5e conformation in the gas phase and in a nonpolar protein environment, but inverts to the 5a/1e conformation upon entering the polar aqueous phase. The binding affinities of the cations and the pK(a) values for the cation-phosphate complexes are derived from thermodynamical analysis.
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Affiliation(s)
- Ping Yang
- Theoretical Division, MS B268, Los Alamos National Laboratory, Los Alamos, NM 87544, USA.
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Islas-Flores I, Villanueva MA. Inositol-1 (or 4)-monophosphatase from Glycine max embryo axes is a phosphatase with broad substrate specificity that includes phytate dephosphorylation. Biochim Biophys Acta 2007; 1770:543-50. [PMID: 17241743 DOI: 10.1016/j.bbagen.2006.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 12/05/2006] [Accepted: 12/06/2006] [Indexed: 10/23/2022]
Abstract
A phosphate-hydrolyzing activity from Glycine max embryo axes was purified by a series of chromatographic steps and electroelution from activity gels, and demonstrated to be an inositol-1 (or 4)-monophosphatase by partial internal amino acid sequence. This enzyme hydrolyzed ATP, sodium pyrophosphate (NaPPi), inositol hexakisphosphate, and inositol 1-monophosphate, but not p-nitrophenyl phosphate, ADP, AMP or glucose 6-P. Using NaPPi as substrate, the highly purified protein hydrolyzed up to 0.4 mmol phosphate min(-1) mg(-1) protein and had a Km(avg) of 235 microM for NaPPi. Since NaPPi is relatively inexpensive and readily available, we used this as substrate for the subsequent characterization. We observed the following: (a) specific inhibition by Li and NaF but not by butanedione monoxime, or orthovanadate; (b) activation by Cu(2+) and Mg(2+); (c) optimum activity at pH 7.4; and (d) temperature stability after 1-h incubations at 37-80 degrees C, with maximum activity at 37 degrees C. The partially purified protein was detected by in-gel activity assays and the band was electroeluted to yield a highly purified protein. Analysis by SDS-PAGE and native IEF-PAGE yielded a single major polypeptide of 29 kDa and pI approximately 5.9, respectively. In addition, in-gel activity from embryo axes and whole hypocotyls at early germination times revealed one high and one intermediate molecular weight isoform, but only the intermediate one corresponded to IMPase. Throughout the post-imbibition period, the activity of the high molecular weight isoform disappeared and IMPase increased, indicating an increasing expression of the enzyme as germination and growth proceeded. These data indicate that the inositol-1 (or 4)-monophosphatase present in the embryo axis of G. max has a wide phosphate substrate specificity, and may play an important role in phosphate metabolism during the germination process.
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Affiliation(s)
- Ignacio Islas-Flores
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, Cuernavaca, Morelos 62250, México
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Rodionov DA, Kurnasov OV, Stec B, Wang Y, Roberts MF, Osterman AL. Genomic identification and in vitro reconstitution of a complete biosynthetic pathway for the osmolyte di-myo-inositol-phosphate. Proc Natl Acad Sci U S A 2007; 104:4279-84. [PMID: 17360515 PMCID: PMC1838593 DOI: 10.1073/pnas.0609279104] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Indexed: 11/18/2022] Open
Abstract
Di-myo-inositol 1,1'-phosphate (DIP) is a major osmoprotecting metabolite in a number of hyperthermophilic species of archaea and bacteria. Although the DIP biosynthesis pathway was previously proposed, genes encoding only two of the four required enzymes, inositol-1-phosphate synthase and inositol monophosphatase, were identified. In this study we used a comparative genomic analysis to predict two additional genes of this pathway (termed dipA and dipB) that remained missing. In Thermotoga maritima both candidate genes (in an originally misannotated locus TM1418) form an operon with the inositol-1-phosphate synthase encoding gene (TM1419). A predicted inositol-mono-phosphate cytidylyltransferase activity was directly confirmed for the purified product of T. maritima gene dipA cloned and expressed in Escherichia coli. The entire DIP pathway was reconstituted in E. coli by cloning of the TM1418-TM1419 operon in pBAD expression vector and confirmed to function in the crude lysate. (31)P NMR and MS analysis revealed that DIP synthesis proceeds via a phosphorylated DIP intermediate, P-DIP, which is generated by the dipB-encoded enzyme, now termed P-DIP synthase. This previously unknown intermediate is apparently converted to the final product, DIP, by an inositol monophosphatase-like phosphatase. These findings allowed us to revise the previously proposed DIP pathway. The genomic survey confirmed its presence in the species known to use DIP for osmoprotection. Among several newly identified species with a postulated DIP pathway, Aeropyrum pernix was directly proven to produce this osmolyte.
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Affiliation(s)
- Dmitry A. Rodionov
- *Burnham Institute for Medical Research, La Jolla, CA 92037
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia; and
| | | | - Boguslaw Stec
- *Burnham Institute for Medical Research, La Jolla, CA 92037
| | - Yan Wang
- Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467; and
| | - Mary F. Roberts
- Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467; and
| | - Andrei L. Osterman
- *Burnham Institute for Medical Research, La Jolla, CA 92037
- Fellowship for Interpretation of Genomes, Burr Ridge, IL 60527
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Binet V, Duthey B, Lecaillon J, Vol C, Quoyer J, Labesse G, Pin JP, Prézeau L. Common structural requirements for heptahelical domain function in class A and class C G protein-coupled receptors. J Biol Chem 2007; 282:12154-63. [PMID: 17310064 PMCID: PMC2565688 DOI: 10.1074/jbc.m611071200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are key players in cell communication. Several classes of such receptors have been identified. Although all GPCRs possess a heptahelical domain directly activating G proteins, important structural and sequence differences within receptors from different classes suggested distinct activation mechanisms. Here we show that highly conserved charged residues likely involved in an interaction network between transmembrane domains (TM) 3 and 6 at the cytoplasmic side of class C GPCRs are critical for activation of the gamma-aminobutyric acid type B receptor. Indeed, the loss of function resulting from the mutation of the conserved lysine residue into aspartate or glutamate in the TM3 of gamma-aminobutyric acid type B(2) can be partly rescued by mutating the conserved acidic residue of TM6 into either lysine or arginine. In addition, mutation of the conserved lysine into an acidic residue leads to a nonfunctional receptor that displays a high agonist affinity. This is reminiscent of a similar ionic network that constitutes a lock stabilizing the inactive state of many class A rhodopsin-like GPCRs. These data reveal that despite their original structure, class C GPCRs share with class A receptors at least some common structural feature controlling G protein activation.
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Affiliation(s)
- Virginie Binet
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
- Centre Hospitalo-Universitaire de Montpellier
CHUI MontpellierFR
| | - Béatrice Duthey
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
| | - Jennifer Lecaillon
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
| | - Claire Vol
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
| | - Julie Quoyer
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
| | - Gilles Labesse
- CBS, Centre de biochimie structurale
CNRS : UMR5048INSERM : U554IFR3Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc29 rue de Navacelles
34090 MONTPELLIER,FR
| | - Jean-Philippe Pin
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
| | - Laurent Prézeau
- IGF, Institut de génomique fonctionnelle
CNRS : UMR5203INSERM : U661Université Montpellier IUniversité Montpellier II - Sciences et Techniques du Languedoc141, Rue de la Cardonille
34094 MONTPELLIER CEDEX 5,FR
- * Correspondence should be adressed to: Laurent Prézeau
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50
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Dinev Z, Gannon CT, Egan C, Watt JA, McConville MJ, Williams SJ. Galactose-derived phosphonate analogues as potential inhibitors of phosphatidylinositol biosynthesis in mycobacteria. Org Biomol Chem 2007; 5:952-9. [PMID: 17340011 DOI: 10.1039/b616450a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Galactose-based phosphonate analogues of myo-inositol-1-phosphate and phosphatidylinositol have been synthesized from methyl beta-d-galactopyranoside. Michaelis-Arbuzov reaction of isopropyl diphenyl phosphite or triisopropyl phosphite with a 6-iodo-3,4-isopropylidene galactoside afforded the corresponding phosphonates. Deprotection of the diphenyl phosphonate afforded methyl beta-d-galactoside 6-phosphonate, an analogue of myo-inositol-1-phosphate. The diisopropyl esters of the diisopropyl phosphonate were selectively deprotected and the corresponding anion was coupled with 1,2-dipalmitoyl-sn-glycerol using dicyclohexylcarbodiimide. Deprotection afforded a methyl beta-d-galactoside-derived analogue of phosphatidylinositol. The galactose-derived analogues of phosphatidylinositol and myo-inositol-1-phosphate were not substrates for mycobacterial mannosyltransferases (at concentrations up to 1 mM) involved in phosphatidylinositol mannoside biosynthesis in a cell-free extract of Mycobacterium smegmatis. The galactose-derived phosphonate analogue of phosphatidylinositol was shown to be an inhibitor at 0.01 mM of PimA mannosyltransferase involved in the synthesis of phosphatidylinositol mannoside from phosphatidylinositol, and a weaker inhibitor of the next mannosyltransferase(s), which catalyzes the mannosylation of phosphatidylinositol mannoside.
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Affiliation(s)
- Zoran Dinev
- School of Chemistry, University of Melbourne, Parkville, Australia
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