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Chakkour M, Greenberg ML. Insights into the roles of inositol hexakisphosphate kinase 1 (IP6K1) in mammalian cellular processes. J Biol Chem 2024; 300:107116. [PMID: 38403246 PMCID: PMC11065760 DOI: 10.1016/j.jbc.2024.107116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 02/27/2024] Open
Abstract
Inositol phosphates and their metabolites play a significant role in several biochemical pathways, gene expression regulation, and phosphate homeostasis. Among the different inositol phosphates, inositol hexakisphosphate (IP6) is a substrate of inositol hexakisphosphate kinases (IP6Ks), which phosphorylate one or more of the IP6 phosphate groups. Pyrophosphorylation of IP6 leads to the formation of inositol pyrophosphates, high-energy signaling molecules that mediate physiological processes through their ability to modify target protein activities, either by directly binding to their target protein or by pyrophosphorylating protein serine residues. 5-diphosphoinositol pentakisphosphate, the most abundant inositol pyrophosphate in mammals, has been extensively studied and found to be significantly involved in a wide range of physiological processes. Three IP6K (IP6K1, IP6K2, and IP6K3) isoforms regulate IP7 synthesis in mammals. Here, we summarize our current understanding of IP6K1's roles in cytoskeletal remodeling, trafficking, cellular migration, metabolism, gene expression, DNA repair, and immunity. We also briefly discuss current gaps in knowledge, highlighting the need for further investigation.
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Affiliation(s)
- Mohamed Chakkour
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA.
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2
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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] [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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3
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Bizzarri M, Monti N, Piombarolo A, Angeloni A, Verna R. Myo-Inositol and D-Chiro-Inositol as Modulators of Ovary Steroidogenesis: A Narrative Review. Nutrients 2023; 15:nu15081875. [PMID: 37111094 PMCID: PMC10145676 DOI: 10.3390/nu15081875] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/11/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Myo-inositol is a natural polyol, the most abundant among the nine possible structural isomers available in living organisms. Inositol confers some distinctive traits that allow for a striking distinction between prokaryotes and eukaryotes, the basic clusters into which organisms are partitioned. Inositol cooperates in numerous biological functions where the polyol participates or by furnishing the fundamental backbone of several related derived metabolites, mostly obtained through the sequential addition of phosphate groups (inositol phosphates, phosphoinositides, and pyrophosphates). Overall myo-inositol and its phosphate metabolites display an entangled network, which is involved in the core of the biochemical processes governing critical transitions inside cells. Noticeably, experimental data have shown that myo-inositol and its most relevant epimer D-chiro-inositol are both necessary to permit a faithful transduction of insulin and of other molecular factors. This improves the complete breakdown of glucose through the citric acid cycle, especially in glucose-greedy tissues, such as the ovary. In particular, while D-chiro-inositol promotes androgen synthesis in the theca layer and down-regulates aromatase and estrogen expression in granulosa cells, myo-inositol strengthens aromatase and FSH receptor expression. Inositol effects on glucose metabolism and steroid hormone synthesis represent an intriguing area of investigation, as recent results have demonstrated that inositol-related metabolites dramatically modulate the expression of several genes. Conversely, treatments including myo-inositol and its isomers have proven to be effective in the management and symptomatic relief of a number of diseases associated with the endocrine function of the ovary, namely polycystic ovarian syndrome.
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Affiliation(s)
- Mariano Bizzarri
- Department of Experimental Medicine, Sapienza University, Via A. Scarpa 16, 00160 Rome, Italy
- Systems Biology Group Lab, Sapienza University, 00160 Rome, Italy
| | - Noemi Monti
- Department of Experimental Medicine, Sapienza University, Via A. Scarpa 16, 00160 Rome, Italy
| | - Aurora Piombarolo
- Department of Experimental Medicine, Sapienza University, Via A. Scarpa 16, 00160 Rome, Italy
| | - Antonio Angeloni
- Department of Experimental Medicine, Sapienza University, Via A. Scarpa 16, 00160 Rome, Italy
| | - Roberto Verna
- Systems Biology Group Lab, Sapienza University, 00160 Rome, Italy
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4
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Fedeli V, Catizone A, Querqui A, Unfer V, Bizzarri M. The Role of Inositols in the Hyperandrogenic Phenotypes of PCOS: A Re-Reading of Larner’s Results. Int J Mol Sci 2023; 24:ijms24076296. [PMID: 37047265 PMCID: PMC10093919 DOI: 10.3390/ijms24076296] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 03/30/2023] Open
Abstract
Polycystic ovarian syndrome (PCOS) is the most common endocrinological disorder in women, in which, besides chronic anovulation/oligomenorrhea and ovarian cysts, hyperandrogenism plays a critical role in a large fraction of subjects. Inositol isomers—myo-Inositol and D-Chiro-Inositol—have recently been pharmacologically effective in managing many PCOS symptoms while rescuing ovarian fertility. However, some disappointing clinical results prompted the reconsideration of their specific biological functions. Surprisingly, D-Chiro-Ins stimulates androgen synthesis and decreases the ovarian estrogen pathway; on the contrary, myo-Ins activates FSH response and aromatase activity, finally mitigating ovarian hyperandrogenism. However, when the two isomers are given in association—according to the physiological ratio of 40:1—patients could benefit from myo-Ins enhanced FSH and estrogen responsiveness, while taking advantage of the insulin-sensitizing effects displayed mostly by D-Chiro-Ins. We need not postulate insulin resistance to explain PCOS pathogenesis, given that insulin hypersensitivity is likely a shared feature of PCOS ovaries. Indeed, even in the presence of physiological insulin stimulation, the PCOS ovary synthesizes D-Chiro-Ins four times more than that measured in control theca cells. The increased D-Chiro-Ins within the ovary is detrimental in preserving steroidogenic control, and this failure can easily explain why treatment strategies based upon high D-Chiro-Ins have been recognized as poorly effective. Within this perspective, two factors emerge as major determinants in PCOS: hyperandrogenism and reduced aromatase expression. Therefore, PCOS could no longer be considered a disease only due to increased androgen synthesis without considering the contemporary downregulation of aromatase and FSH receptors. Furthermore, these findings suggest that inositols can be specifically effective only for those PCOS phenotypes featured by hyperandrogenism.
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Ito M, Fujii N, Kohara S, Hori S, Tanaka M, Wittwer C, Kikuchi K, Iijima T, Kakimoto Y, Hirabayashi K, Kurotaki D, Jessen HJ, Saiardi A, Nagata E. Inositol pyrophosphate profiling reveals regulatory roles of IP6K2-dependent enhanced IP 7 metabolism in the enteric nervous system. J Biol Chem 2023; 299:102928. [PMID: 36681123 PMCID: PMC9957762 DOI: 10.1016/j.jbc.2023.102928] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 01/20/2023] Open
Abstract
Inositol pyrophosphates regulate diverse physiological processes; to better understand their functional roles, assessing their tissue-specific distribution is important. Here, we profiled inositol pyrophosphate levels in mammalian organs using an originally designed liquid chromatography-mass spectrometry (LC-MS) protocol and discovered that the gastrointestinal tract (GIT) contained the highest levels of diphosphoinositol pentakisphosphate (IP7) and its precursor inositol hexakisphosphate (IP6). Although their absolute levels in the GIT are diet dependent, elevated IP7 metabolism still exists under dietary regimens devoid of exogenous IP7. Of the major GIT cells, enteric neurons selectively express the IP7-synthesizing enzyme IP6K2. We found that IP6K2-knockout mice exhibited significantly impaired IP7 metabolism in the various organs including the proximal GIT. In addition, our LC-MS analysis displayed that genetic ablation of IP6K2 significantly impaired IP7 metabolism in the gut and duodenal muscularis externa containing myenteric plexus. Whole transcriptome analysis of duodenal muscularis externa further suggested that IP6K2 inhibition significantly altered expression levels of the gene sets associated with mature neurons, neural progenitor/stem cells, and glial cells, as well as of certain genes modulating neuronal differentiation and functioning, implying critical roles of the IP6K2-IP7 axis in developmental and functional regulation of the enteric nervous system. These results collectively reveal an unexpected role of mammalian IP7-a highly active IP6K2-IP7 pathway is conducive to the enteric nervous system.
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Affiliation(s)
- Masatoshi Ito
- Support Center for Medical Research and Education, Tokai University, Isehara, Japan.
| | - Natsuko Fujii
- Department of Neurology, Tokai University School of Medicine, Isehara, Japan
| | - Saori Kohara
- Department of Neurology, Tokai University School of Medicine, Isehara, Japan
| | - Shuho Hori
- Support Center for Medical Research and Education, Tokai University, Isehara, Japan
| | - Masayuki Tanaka
- Support Center for Medical Research and Education, Tokai University, Isehara, Japan
| | | | - Kenta Kikuchi
- Laboratory of Chromatin Organization in Immune Cell Development, International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Takatoshi Iijima
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Japan
| | - Yu Kakimoto
- Department of Forensic Medicine, Tokai University School of Medicine, Isehara, Japan
| | - Kenichi Hirabayashi
- Department of Pathology, Tokai University School of Medicine, Isehara, Japan
| | - Daisuke Kurotaki
- Laboratory of Chromatin Organization in Immune Cell Development, International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Henning J Jessen
- Institute of Organic Chemistry, University of Freiburg, Freiburg, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Eiichiro Nagata
- Department of Neurology, Tokai University School of Medicine, Isehara, Japan.
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Osorio T, Scoma ER, Shain DH, Melissaratos DS, Riggs LM, Hambardikar V, Solesio ME. The Glacier Ice Worm, Mesenchytraeus solifugus, Elevates Mitochondrial Inorganic Polyphosphate (PolyP) Levels in Response to Stress. BIOLOGY 2022; 11:biology11121771. [PMID: 36552279 PMCID: PMC9774917 DOI: 10.3390/biology11121771] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
The inorganic polymer, polyphosphate (polyP), is present in all organisms examined to date with putative functions ranging from the maintenance of bioenergetics to stress resilience and protein homeostasis. Bioenergetics in the glacier-obligate, segmented worm, Mesenchytraeus solifugus, is characterized by a paradoxical increase in intracellular ATP levels as temperatures decline. We show here that steady-state, mitochondrial polyP levels vary among species of Annelida, but were elevated only in M. solifugus in response to thermal stress. In contrast, polyP levels decreased with temperature in the mesophilic worm, Enchytraeus crypticus. These results identify fundamentally different bioenergetic strategies between closely related annelid worms, and suggest that I worm mitochondria maintain ATP and polyP in a dynamic equilibrium.
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Hambardikar V, Guitart-Mampel M, Scoma ER, Urquiza P, Nagana GGA, Raftery D, Collins JA, Solesio ME. Enzymatic Depletion of Mitochondrial Inorganic Polyphosphate (polyP) Increases the Generation of Reactive Oxygen Species (ROS) and the Activity of the Pentose Phosphate Pathway (PPP) in Mammalian Cells. Antioxidants (Basel) 2022; 11:685. [PMID: 35453370 PMCID: PMC9029763 DOI: 10.3390/antiox11040685] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/21/2022] [Accepted: 03/23/2022] [Indexed: 01/27/2023] Open
Abstract
Inorganic polyphosphate (polyP) is an ancient biopolymer that is well preserved throughout evolution and present in all studied organisms. In mammals, it shows a high co-localization with mitochondria, and it has been demonstrated to be involved in the homeostasis of key processes within the organelle, including mitochondrial bioenergetics. However, the exact extent of the effects of polyP on the regulation of cellular bioenergetics, as well as the mechanisms explaining these effects, still remain poorly understood. Here, using HEK293 mammalian cells under Wild-type (Wt) and MitoPPX (cells enzymatically depleted of mitochondrial polyP) conditions, we show that depletion of polyP within mitochondria increased oxidative stress conditions. This is characterized by enhanced mitochondrial O2- and intracellular H2O2 levels, which may be a consequence of the dysregulation of oxidative phosphorylation (OXPHOS) that we have demonstrated in MitoPPX cells in our previous work. These findings were associated with an increase in basal peroxiredoxin-1 (Prx1), superoxide dismutase-2 (SOD2), and thioredoxin (Trx) antioxidant protein levels. Using 13C-NMR and immunoblotting, we assayed the status of glycolysis and the pentose phosphate pathway (PPP) in Wt and MitoPPX cells. Our results show that MitoPPX cells display a significant increase in the activity of the PPP and an increase in the protein levels of transaldolase (TAL), which is a crucial component of the non-oxidative phase of the PPP and is involved in the regulation of oxidative stress. In addition, we observed a trend towards increased glycolysis in MitoPPX cells, which corroborates our prior work. Here, for the first time, we show the crucial role played by mitochondrial polyP in the regulation of mammalian redox homeostasis. Moreover, we demonstrate a significant effect of mitochondrial polyP on the regulation of global cellular bioenergetics in these cells.
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Affiliation(s)
- Vedangi Hambardikar
- Department of Biology and Center for Computational and Integrative Biology (CCIB), College of Arts and Sciences, Rutgers University, Camden, NJ 08103, USA; (V.H.); (M.G.-M.); (E.R.S.); (P.U.)
| | - Mariona Guitart-Mampel
- Department of Biology and Center for Computational and Integrative Biology (CCIB), College of Arts and Sciences, Rutgers University, Camden, NJ 08103, USA; (V.H.); (M.G.-M.); (E.R.S.); (P.U.)
| | - Ernest R. Scoma
- Department of Biology and Center for Computational and Integrative Biology (CCIB), College of Arts and Sciences, Rutgers University, Camden, NJ 08103, USA; (V.H.); (M.G.-M.); (E.R.S.); (P.U.)
| | - Pedro Urquiza
- Department of Biology and Center for Computational and Integrative Biology (CCIB), College of Arts and Sciences, Rutgers University, Camden, NJ 08103, USA; (V.H.); (M.G.-M.); (E.R.S.); (P.U.)
| | - Gowda G. A. Nagana
- Mitochondrial and Metabolism Center, University of Washington, Seattle, WA 98109, USA; (G.G.A.N.); (D.R.)
| | - Daniel Raftery
- Mitochondrial and Metabolism Center, University of Washington, Seattle, WA 98109, USA; (G.G.A.N.); (D.R.)
| | - John A. Collins
- Department of Orthopedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA;
| | - Maria E. Solesio
- Department of Biology and Center for Computational and Integrative Biology (CCIB), College of Arts and Sciences, Rutgers University, Camden, NJ 08103, USA; (V.H.); (M.G.-M.); (E.R.S.); (P.U.)
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Whole Body Ip6k1 Deletion Protects Mice from Age-Induced Weight Gain, Insulin Resistance and Metabolic Dysfunction. Int J Mol Sci 2022; 23:ijms23042059. [PMID: 35216174 PMCID: PMC8878859 DOI: 10.3390/ijms23042059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/05/2022] [Accepted: 02/10/2022] [Indexed: 12/21/2022] Open
Abstract
(1) Background: We previously demonstrated that disruption of IP6K1 improves metabolism, protecting mice from high-fat diet-induced obesity, insulin resistance, and non-alcoholic fatty liver disease and steatohepatitis. Age-induced metabolic dysfunction is a major risk factor for metabolic diseases. The involvement of IP6K1 in this process is unknown. (2) Methods: Here, we compared body and fat mass, insulin sensitivity, energy expenditure and serum-, adipose tissue- and liver-metabolic parameters of chow-fed, aged, wild type (aWT) and whole body Ip6k1 knockout (aKO) mice. (3) Results: IP6K1 was upregulated in the adipose tissue and liver of aWT mice compared to young WT mice. Moreover, Ip6k1 deletion blocked age-induced increase in body- and fat-weight and insulin resistance in mice. aKO mice oxidized carbohydrates more efficiently. The knockouts displayed reduced levels of serum insulin, triglycerides, and non-esterified fatty acids. Ip6k1 deletion partly protected age-induced decline of the thermogenic uncoupling protein UCP1 in inguinal white adipose tissue. Targets inhibited by IP6K1 activity such as the insulin sensitivity- and energy expenditure-inducing protein kinases, protein kinase B (PKB/Akt) and AMP-activated protein kinase (AMPK), were activated in the adipose tissue and liver of aKO mice. (4) Conclusions: Ip6k1 deletion maintains healthy metabolism in aging and thus, targeting this kinase may delay the development of age-induced metabolic dysfunction.
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Phosphate Starvation by Energy Metabolism Disturbance in Candida albicansvip1Δ/Δ Induces Lipid Droplet Accumulation and Cell Membrane Damage. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030686. [PMID: 35163951 PMCID: PMC8839741 DOI: 10.3390/molecules27030686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/11/2022] [Accepted: 01/15/2022] [Indexed: 11/17/2022]
Abstract
Phosphorus in the form of phosphate (Pi) is an essential element for metabolic processes, including lipid metabolism. In yeast, the inositol polyphosphate kinase vip1 mediated synthesis of inositol heptakisphosphate (IP7) regulates the phosphate-responsive (PHO) signaling pathway, which plays an important role in response to Pi stress. The role of vip1 in Pi stress and lipid metabolism of Candida albicans has not yet been studied. We found that when vip1Δ/Δ was grown in glucose medium, if Pi was supplemented in the medium or mitochondrial Pi transporter was overexpressed in the strain, the lipid droplet (LD) content was reduced and membrane damage was alleviated. However, further studies showed that neither the addition of Pi nor the overexpression of the Pi transporter affected the energy balance of vip1Δ/Δ. In addition, the LD content of vip1Δ/Δ grown in Pi limitation medium PNMC was lower than that grown in SC, and the metabolic activity of vip1Δ/Δ grown in PNMC was also lower than that grown in SC medium. This suggests that the increase in Pi demand by a high energy metabolic rate is the cause of LD accumulation in vip1Δ/Δ. In addition, in the vip1Δ/Δ strains, the core transcription factor PHO4 in the PHO pathway was transported to the vacuole and degraded, which reduced the pathway activity. However, this does not mean that knocking out vip1 completely blocks the activation of the PHO pathway, because the LD content of vip1Δ/Δ grown in the medium with β-glycerol phosphate as the Pi source was significantly reduced. In summary, the increased Pi demand and the decreased PHO pathway activity in vip1Δ/Δ ultimately lead to LD accumulation and cell membrane damage.
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10
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Couso I, Smythers AL, Ford MM, Umen JG, Crespo JL, Hicks LM. Inositol polyphosphates and target of rapamycin kinase signalling govern photosystem II protein phosphorylation and photosynthetic function under light stress in Chlamydomonas. THE NEW PHYTOLOGIST 2021; 232:2011-2025. [PMID: 34529857 DOI: 10.1111/nph.17741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 09/09/2021] [Indexed: 05/28/2023]
Abstract
Stress and nutrient availability influence cell proliferation through complex intracellular signalling networks. In a previous study it was found that pyro-inositol polyphosphates (InsP7 and InsP8 ) produced by VIP1 kinase, and target of rapamycin (TOR) kinase signalling interacted synergistically to control cell growth and lipid metabolism in the green alga Chlamydomonas reinhardtii. However, the relationship between InsPs and TOR was not completely elucidated. We used an in vivo assay for TOR activity together with global proteomic and phosphoproteomic analyses to assess differences between wild-type and vip1-1 in the presence and absence of rapamycin. We found that TOR signalling is more severely affected by the inhibitor rapamycin in a vip1-1 mutant compared with wild-type, indicating that InsP7 and InsP8 produced by VIP1 act independently but also coordinately with TOR. Additionally, among hundreds of differentially phosphorylated peptides detected, an enrichment for photosynthesis-related proteins was observed, particularly photosystem II proteins. The significance of these results was underscored by the finding that vip1-1 strains show multiple defects in photosynthetic physiology that were exacerbated under high light conditions. These results suggest a novel role for inositol pyrophosphates and TOR signalling in coordinating photosystem phosphorylation patterns in Chlamydomonas cells in response to light stress and possibly other stresses.
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Affiliation(s)
- Inmaculada Couso
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla, Avda. Américo Vespucio, 49, Sevilla, 41092, Spain
| | - Amanda L Smythers
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Megan M Ford
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - James G Umen
- Donald Danforth Plant Science Center, St Louis, MO, 63132, USA
| | - José L Crespo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla, Avda. Américo Vespucio, 49, Sevilla, 41092, Spain
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
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11
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Mukherjee S, Chakraborty M, Ulmasov B, McCommis K, Zhang J, Carpenter D, Msengi EN, Haubner J, Guo C, Pike DP, Ghoshal S, Ford DA, Neuschwander-Tetri BA, Chakraborty A. Pleiotropic actions of IP6K1 mediate hepatic metabolic dysfunction to promote nonalcoholic fatty liver disease and steatohepatitis. Mol Metab 2021; 54:101364. [PMID: 34757046 PMCID: PMC8609165 DOI: 10.1016/j.molmet.2021.101364] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/11/2021] [Accepted: 10/23/2021] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE Obesity and insulin resistance greatly increase the risk of nonalcoholic fatty liver disease and steatohepatitis (NAFLD/NASH). We have previously discovered that whole-body and adipocyte-specific Ip6k1deletion protects mice from high-fat-diet-induced obesity and insulin resistance due to improved adipocyte thermogenesis and insulin signaling. Here, we aimed to determine the impact of hepatocyte-specific and whole-body Ip6k1 deletion (HKO and Ip6k1-KO or KO) on liver metabolism and NAFLD/NASH. METHODS Body weight and composition; energy expenditure; glycemic profiles; and serum and liver metabolic, inflammatory, fibrotic and toxicity parameters were assessed in mice fed Western and high-fructose diet (HFrD) (WD: 40% kcal fat, 1.25% cholesterol, no added choline and HFrD: 60% kcal fructose). Mitochondrial oxidative capacity was evaluated in isolated hepatocytes. RNA-Seq was performed in liver samples. Livers from human NASH patients were analyzed by immunoblotting and mass spectrometry. RESULTS HKO mice displayed increased hepatocyte mitochondrial oxidative capacity and improved insulin sensitivity but were not resistant to body weight gain. Improved hepatocyte metabolism partially protected HKO mice from NAFLD/NASH. In contrast, enhanced whole-body metabolism and reduced body fat accumulation significantly protected whole-body Ip6k1-KO mice from NAFLD/NASH. Mitochondrial oxidative pathways were upregulated, whereas gluconeogenic and fibrogenic pathways were downregulated in Ip6k1-KO livers. Furthermore, IP6K1 was upregulated in human NASH livers and interacted with the enzyme O-GlcNAcase that reduces protein O-GlcNAcylation. Protein O-GlcNAcylation was found to be reduced in Ip6k1-KO and HKO mouse livers. CONCLUSION Pleiotropic actions of IP6K1 in the liver and other metabolic tissues mediate hepatic metabolic dysfunction and NAFLD/NASH, and thus IP6K1 deletion may be a potential treatment target for this disease.
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Affiliation(s)
- Sandip Mukherjee
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Molee Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Barbara Ulmasov
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Kyle McCommis
- Department of Biochemistry, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Jinsong Zhang
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Danielle Carpenter
- Department of Pathology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Eliwaza Naomi Msengi
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Jake Haubner
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Chun Guo
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Daniel P Pike
- Department of Biochemistry, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Sarbani Ghoshal
- Department of Biological Sc. and Geology, QCC-CUNY, Bayside, NY, USA
| | - David A Ford
- Department of Biochemistry, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Brent A Neuschwander-Tetri
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA
| | - Anutosh Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA.
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12
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The inositol pyrophosphate metabolism of Dictyostelium discoideum does not regulate inorganic polyphosphate (polyP) synthesis. Adv Biol Regul 2021; 83:100835. [PMID: 34782304 PMCID: PMC8885430 DOI: 10.1016/j.jbior.2021.100835] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 10/28/2021] [Indexed: 11/23/2022]
Abstract
Initial studies on the inositol phosphates metabolism were enabled by the social amoeba Dictyostelium discoideum. The abundant amount of inositol hexakisphosphate (IP6 also known as Phytic acid) present in the amoeba allowed the discovery of the more polar inositol pyrophosphates, IP7 and IP8, possessing one or two high energy phosphoanhydride bonds, respectively. Considering the contemporary growing interest in inositol pyrophosphates, it is surprising that in recent years D. discoideum, has contributed little to our understanding of their metabolism and function. This work fulfils this lacuna, by analysing the ip6k, ppip5k and ip6k-ppip5K amoeba null strains using PAGE, 13C-NMR and CE-MS analysis. Our study reveals an inositol pyrophosphate metabolism more complex than previously thought. The amoeba Ip6k synthesizes the 4/6-IP7 in contrast to the 5-IP7 isomer synthesized by the mammalian homologue. The amoeba Ppip5k synthesizes the same 1/3-IP7 as the mammalian enzyme. In D. discoideum, the ip6k strain possesses residual amounts of IP7. The residual IP7 is also present in the ip6k-ppip5K strain, while the ppip5k single mutant shows a decrease in both IP7 and IP8 levels. This phenotype is in contrast to the increase in IP7 observable in the yeast vip1Δ strain. The presence of IP8 in ppip5k and the presence of IP7 in ip6k-ppip5K indicate the existence of an additional inositol pyrophosphate synthesizing enzyme. Additionally, we investigated the existence of a metabolic relationship between inositol pyrophosphate synthesis and inorganic polyphosphate (polyP) metabolism as observed in yeast. These studies reveal that contrary to the yeast, Ip6k and Ppip5k do not control polyP cellular level in amoeba.
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13
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Murry R, Traxler L, Pötschner J, Krüger T, Kniemeyer O, Krause K, Kothe E. Inositol Signaling in the Basidiomycete Fungus Schizophyllum commune. J Fungi (Basel) 2021; 7:jof7060470. [PMID: 34200898 PMCID: PMC8230515 DOI: 10.3390/jof7060470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/07/2021] [Accepted: 06/07/2021] [Indexed: 12/26/2022] Open
Abstract
Intracellular signaling is conserved in eukaryotes to allow for response to extracellular signals and to regulate development and cellular functions. In fungi, inositol phosphate signaling has been shown to be involved in growth, sexual reproduction, and metabolic adaptation. However, reports on mushroom-forming fungi are lacking so far. In Schizophyllum commune, an inositol monophosphatase has been found up-regulated during sexual development. The enzyme is crucial for inositol cycling, where it catalyzes the last step of inositol phosphate metabolism, restoring the inositol pool from the monophosphorylated inositol monophosphate. We overexpressed the gene in this model basidiomycete and verified its involvement in cell wall integrity and intracellular trafficking. Strong phenotypes in mushroom formation and cell metabolism were evidenced by proteome analyses. In addition, altered inositol signaling was shown to be involved in tolerance towards cesium and zinc, and increased metal tolerance towards cadmium, associated with induced expression of kinases and repression of phosphatases within the inositol cycle. The presence of the heavy metals Sr, Cs, Cd, and Zn lowered intracellular calcium levels. We could develop a model integrating inositol signaling in the known signal transduction pathways governed by Ras, G-protein coupled receptors, and cAMP, and elucidate their different roles in development.
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Affiliation(s)
- Reyna Murry
- Institute of Microbiology, Friedrich Schiller University Jena, Microbial Communication, Neugasse 25, 07743 Jena, Germany; (R.M.); (L.T.); (J.P.); (K.K.)
| | - Lea Traxler
- Institute of Microbiology, Friedrich Schiller University Jena, Microbial Communication, Neugasse 25, 07743 Jena, Germany; (R.M.); (L.T.); (J.P.); (K.K.)
| | - Jessica Pötschner
- Institute of Microbiology, Friedrich Schiller University Jena, Microbial Communication, Neugasse 25, 07743 Jena, Germany; (R.M.); (L.T.); (J.P.); (K.K.)
| | - Thomas Krüger
- Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Molecular and Applied Microbiology, Adolf-Reichwein-Straße 23, 07745 Jena, Germany; (T.K.); (O.K.)
| | - Olaf Kniemeyer
- Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, Molecular and Applied Microbiology, Adolf-Reichwein-Straße 23, 07745 Jena, Germany; (T.K.); (O.K.)
| | - Katrin Krause
- Institute of Microbiology, Friedrich Schiller University Jena, Microbial Communication, Neugasse 25, 07743 Jena, Germany; (R.M.); (L.T.); (J.P.); (K.K.)
| | - Erika Kothe
- Institute of Microbiology, Friedrich Schiller University Jena, Microbial Communication, Neugasse 25, 07743 Jena, Germany; (R.M.); (L.T.); (J.P.); (K.K.)
- Correspondence: ; Tel.: +49-(0)3641-949291
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14
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Packa V, Howell T, Bostan V, Furdui VI. Phosphorus-based metabolic pathway tracers in surface waters. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:29498-29508. [PMID: 33559082 DOI: 10.1007/s11356-021-12697-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Trophic status in surface waters has been mostly monitored by measuring soluble reactive phosphorus (SRP) and total phosphorus (TP). Additional to these common parameters, a two-dimensional ion chromatography mass spectrometry (2D-IC-MS) method was used to simultaneously measure soluble phosphate (Pi), pyrophosphate (PPi), and eleven phosphate-containing metabolites (P-metabolites) in Lake Ontario and its tributaries. From the additional P species, PPi, adenosine 5'-monophosphate (AMP), glucose 6-phosphate (G-P), D-fructose 6-phosphate (F-P), D-fructose 1,6-biphosphate (F-2P), D-ribulose 5-phosphate (R-P), D-ribulose 1,5-bisphosphate (R-2P), and D-(-)-3-phosphoglyceric acid (PGA) were detected and quantified in the lake and river samples. The additional multivariate statistical analysis identified similarities between samples collected at different locations. The presence of R-P, R-2P, and F-2P in Lake Ontario tributaries seems to be mainly related to the Calvin cycle, while the lack of all these three P-metabolites and higher PGA levels than G-P in Toronto Harbour samples seems to be the result of depleted Calvin cycle, pentose phosphate, and glycolysis metabolic pathways.
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Affiliation(s)
- Vlastimil Packa
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Road, Toronto, ON, M9P 3V6, Canada
- Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3, Canada
| | - Todd Howell
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Road, Toronto, ON, M9P 3V6, Canada
| | - Vadim Bostan
- Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3, Canada
| | - Vasile I Furdui
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Road, Toronto, ON, M9P 3V6, Canada.
- Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3, Canada.
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15
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Gupta R, Laxman S. Cycles, sources, and sinks: Conceptualizing how phosphate balance modulates carbon flux using yeast metabolic networks. eLife 2021; 10:e63341. [PMID: 33544078 PMCID: PMC7864628 DOI: 10.7554/elife.63341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/20/2021] [Indexed: 12/11/2022] Open
Abstract
Phosphates are ubiquitous molecules that enable critical intracellular biochemical reactions. Therefore, cells have elaborate responses to phosphate limitation. Our understanding of long-term transcriptional responses to phosphate limitation is extensive. Contrastingly, a systems-level perspective presenting unifying biochemical concepts to interpret how phosphate balance is critically coupled to (and controls) metabolic information flow is missing. To conceptualize such processes, utilizing yeast metabolic networks we categorize phosphates utilized in metabolism into cycles, sources and sinks. Through this, we identify metabolic reactions leading to putative phosphate sources or sinks. With this conceptualization, we illustrate how mass action driven flux towards sources and sinks enable cells to manage phosphate availability during transient/immediate phosphate limitations. We thereby identify how intracellular phosphate availability will predictably alter specific nodes in carbon metabolism, and determine signature cellular metabolic states. Finally, we identify a need to understand intracellular phosphate pools, in order to address mechanisms of phosphate regulation and restoration.
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Affiliation(s)
- Ritu Gupta
- Institute for Stem Cell Science and Regenerative Medicine (inStem)BangaloreIndia
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine (inStem)BangaloreIndia
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16
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Minini M, Senni A, Unfer V, Bizzarri M. The Key Role of IP 6K: A Novel Target for Anticancer Treatments? Molecules 2020; 25:molecules25194401. [PMID: 32992691 PMCID: PMC7583815 DOI: 10.3390/molecules25194401] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/29/2022] Open
Abstract
Inositol and its phosphate metabolites play a pivotal role in several biochemical pathways and gene expression regulation: inositol pyrophosphates (PP-IPs) have been increasingly appreciated as key signaling modulators. Fluctuations in their intracellular levels hugely impact the transfer of phosphates and the phosphorylation status of several target proteins. Pharmacological modulation of the proteins associated with PP-IP activities has proved to be beneficial in various pathological settings. IP7 has been extensively studied and found to play a key role in pathways associated with PP-IP activities. Three inositol hexakisphosphate kinase (IP6K) isoforms regulate IP7 synthesis in mammals. Genomic deletion or enzymic inhibition of IP6K1 has been shown to reduce cell invasiveness and migration capacity, protecting against chemical-induced carcinogenesis. IP6K1 could therefore be a useful target in anticancer treatment. Here, we summarize the current understanding that established IP6K1 and the other IP6K isoforms as possible targets for cancer therapy. However, it will be necessary to determine whether pharmacological inhibition of IP6K is safe enough to begin clinical study. The development of safe and selective inhibitors of IP6K isoforms is required to minimize undesirable effects.
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Affiliation(s)
- Mirko Minini
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
- Department of Surgery ‘P. Valdoni’, Sapienza University of Rome, 00161 Rome, Italy
- Systems Biology Group Lab, Sapienza University of Rome, 00185 Rome, Italy;
- Correspondence: (M.M.); (M.B.)
| | - Alice Senni
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
- Department of Surgery ‘P. Valdoni’, Sapienza University of Rome, 00161 Rome, Italy
| | - Vittorio Unfer
- Systems Biology Group Lab, Sapienza University of Rome, 00185 Rome, Italy;
| | - Mariano Bizzarri
- Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy;
- Systems Biology Group Lab, Sapienza University of Rome, 00185 Rome, Italy;
- Correspondence: (M.M.); (M.B.)
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17
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Furkert D, Hostachy S, Nadler-Holly M, Fiedler D. Triplexed Affinity Reagents to Sample the Mammalian Inositol Pyrophosphate Interactome. Cell Chem Biol 2020; 27:1097-1108.e4. [PMID: 32783964 DOI: 10.1016/j.chembiol.2020.07.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/19/2020] [Accepted: 07/22/2020] [Indexed: 11/15/2022]
Abstract
The inositol pyrophosphates (PP-InsPs) are a ubiquitous group of highly phosphorylated eukaryotic messengers. They have been linked to a panoply of central cellular processes, but a detailed understanding of the discrete signaling events is lacking in most cases. To create a more mechanistic picture of PP-InsP signaling, we sought to annotate the mammalian interactome of the most abundant inositol pyrophosphate 5PP-InsP5. To do so, triplexed affinity reagents were developed, in which a metabolically stable PP-InsP analog was immobilized in three different ways. Application of these triplexed reagents to mammalian lysates identified between 300 and 400 putative interacting proteins. These interactomes revealed connections between 5PP-InsP5 and central cellular regulators, such as lipid phosphatases, protein kinases, and GTPases, and identified protein domains commonly targeted by 5PP-InsP5. Both the triplexed affinity reagents, and the proteomic datasets, constitute powerful resources for the community, to launch future investigations into the multiple signaling modalities of inositol pyrophosphates.
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Affiliation(s)
- David Furkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany; Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Michal Nadler-Holly
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany; Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
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18
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Sanz-Luque E, Bhaya D, Grossman AR. Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae. FRONTIERS IN PLANT SCIENCE 2020; 11:938. [PMID: 32670331 PMCID: PMC7332688 DOI: 10.3389/fpls.2020.00938] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/09/2020] [Indexed: 05/19/2023]
Abstract
Polyphosphate (polyP), a polymer of orthophosphate (PO4 3-) of varying lengths, has been identified in all kingdoms of life. It can serve as a source of chemical bond energy (phosphoanhydride bond) that may have been used by biological systems prior to the evolution of ATP. Intracellular polyP is mainly stored as granules in specific vacuoles called acidocalcisomes, and its synthesis and accumulation appear to impact a myriad of cellular functions. It serves as a reservoir for inorganic PO4 3- and an energy source for fueling cellular metabolism, participates in maintaining adenylate and metal cation homeostasis, functions as a scaffold for sequestering cations, exhibits chaperone function, covalently binds to proteins to modify their activity, and enables normal acclimation of cells to stress conditions. PolyP also appears to have a role in symbiotic and parasitic associations, and in higher eukaryotes, low polyP levels seem to impact cancerous proliferation, apoptosis, procoagulant and proinflammatory responses and cause defects in TOR signaling. In this review, we discuss the metabolism, storage, and function of polyP in photosynthetic microbes, which mostly includes research on green algae and cyanobacteria. We focus on factors that impact polyP synthesis, specific enzymes required for its synthesis and degradation, sequestration of polyP in acidocalcisomes, its role in cellular energetics, acclimation processes, and metal homeostasis, and then transition to its potential applications for bioremediation and medical purposes.
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Affiliation(s)
- Emanuel Sanz-Luque
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
- Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain
| | - Devaki Bhaya
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
| | - Arthur R. Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
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19
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Ganguli S, Shah A, Hamid A, Singh A, Palakurti R, Bhandari R. A high energy phosphate jump - From pyrophospho-inositol to pyrophospho-serine. Adv Biol Regul 2020; 75:100662. [PMID: 31668836 DOI: 10.1016/j.jbior.2019.100662] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/26/2019] [Accepted: 09/30/2019] [Indexed: 06/10/2023]
Abstract
Inositol pyrophosphates (PP-IPs) are a class of energy rich metabolites present in all eukaryotic cells. The hydroxyl groups on these water soluble derivatives of inositol are substituted with diphosphate and monophosphate moieties. Since the discovery of PP-IPs in the early 1990s, enormous progress has been made in uncovering pleiotropic roles for these small molecules in cellular physiology. PP-IPs exert their effect on proteins in two ways - allosteric regulation by direct binding, or post-translational regulation by serine pyrophosphorylation, a modification unique to PP-IPs. Serine pyrophosphorylation is achieved by Mg2+-dependent, but enzyme independent transfer of a β-phosphate from a PP-IP to a pre-phosphorylated serine residue located in an acidic motif, within an intrinsically disordered protein sequence. This distinctive post-translational modification has been shown to regulate diverse cellular processes, including rRNA synthesis, glycolysis, and vesicle transport. However, our understanding of the molecular details of this phosphotransfer from pyrophospho-inositol to generate pyrophospho-serine, is still nascent. This review discusses our current knowledge of protein pyrophosphorylation, and recent advances in understanding the mechanism of this important yet overlooked post-translational modification.
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Affiliation(s)
- Shubhra Ganguli
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India; Manipal Academy of Higher Education, Manipal, 576104, India
| | - Akruti Shah
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India; Manipal Academy of Higher Education, Manipal, 576104, India
| | - Aisha Hamid
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India
| | - Arpita Singh
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India
| | - Ravichand Palakurti
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India.
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20
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Xie L, Rajpurkar A, Quarles E, Taube N, Rai AS, Erba J, Sliwinski B, Markowitz M, Jakob U, Knoefler D. Accumulation of Nucleolar Inorganic Polyphosphate Is a Cellular Response to Cisplatin-Induced Apoptosis. Front Oncol 2019; 9:1410. [PMID: 31921667 PMCID: PMC6920253 DOI: 10.3389/fonc.2019.01410] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/28/2019] [Indexed: 01/09/2023] Open
Abstract
The chemotherapeutic drug cisplatin, which targets DNA, serves as one of the main staples in cancer treatment. Yet, the therapeutic application of cisplatin is limited by two major challenges: the occurrence of reversible and irreversible side effects due to non-specific toxicity, and the intrinsic or developing resistance of tumor cells toward cisplatin. Here we demonstrate that cancer cells respond to cisplatin treatment with the nucleolar accumulation of inorganic polyphosphate (polyP), a universally conserved high-energy compound. PolyP accumulation positively correlates with the levels of activated caspase-3, suggesting a novel role of polyP in cisplatin-mediated apoptosis. In support of this finding, we discovered that administration of exogenous polyP increases cisplatin-induced toxicity in select cancer cell lines, raising the exciting possibility that enhancing endogenous polyP levels might be a novel mechanism to sensitize cancer cells to cisplatin treatment.
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Affiliation(s)
- Lihan Xie
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Asavari Rajpurkar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Ellen Quarles
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Nicole Taube
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Akash S Rai
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Jake Erba
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Benjamin Sliwinski
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Moses Markowitz
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Daniela Knoefler
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
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21
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Dohle W, Su X, Mills SJ, Rossi A, Taylor CW, Potter BVL. A synthetic cyclitol-nucleoside conjugate polyphosphate is a highly potent second messenger mimic. Chem Sci 2019; 10:5382-5390. [PMID: 31171961 PMCID: PMC6540904 DOI: 10.1039/c9sc00445a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/23/2019] [Indexed: 12/11/2022] Open
Abstract
Reactions that form sec-sec ethers are well known, but few lead to compounds with dense functionality around the O-linkage. Replacement of the α-glucopyranosyl unit of adenophostin A, a potent d-myo-inositol 1,4,5-trisphosphate (IP3R) agonist, with a d-chiro-inositol surrogate acting substantially as a pseudosugar, leads to "d-chiro-inositol adenophostin". At its core, this cyclitol-nucleoside trisphosphate comprises a nucleoside sugar linked via an axial d-chiro-inositol 1-hydroxyl-adenosine 3'-ribose ether linkage. A divergent synthesis of d-chiro-inositol adenophostin has been achieved. Key features of the synthetic strategy to produce a triol for phosphorylation include a new selective mono-tosylation of racemic 1,2:4,5-di-O-isopropylidene-myo-inositol using tosyl imidazole; subsequent conversion of the product into separable camphanate ester derivatives, one leading to a chiral myo-inositol triflate used as a synthetic building block and the other to l-5-O-methyl-myo-inositol [l-(+)-bornesitol] to assign the absolute configuration; the nucleophilic coupling of an alkoxide of a ribose pent-4-ene orthoester unit with a structurally rigid chiral myo-inositol triflate derivative, representing the first sec-sec ether formation between a cyclitol and ribose. Reaction of the coupled product with a silylated nucleobase completes the assembly of the core structure. Further protecting group manipulation, mixed O- and N-phosphorylation, and subsequent removal of all protecting groups in a single step achieves the final product, avoiding a separate N6 protection/deprotection strategy. d-chiro-Inositol adenophostin evoked Ca2+ release through IP3Rs at lower concentrations than adenophostin A, hitherto the most potent known agonist of IP3Rs.
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Affiliation(s)
- Wolfgang Dohle
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
| | - Xiangdong Su
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
| | - Stephen J. Mills
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
| | - Ana M. Rossi
- Department of Pharmacology
, University of Cambridge
,
Tennis Court Road
, Cambridge
, CB2 1PD
, UK
| | - Colin W. Taylor
- Department of Pharmacology
, University of Cambridge
,
Tennis Court Road
, Cambridge
, CB2 1PD
, UK
| | - Barry V. L. Potter
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
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22
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Murry R, Kniemeyer O, Krause K, Saiardi A, Kothe E. Crosstalk between Ras and inositol phosphate signaling revealed by lithium action on inositol monophosphatase in Schizophyllum commune. Adv Biol Regul 2019; 72:78-88. [PMID: 30639095 PMCID: PMC6520614 DOI: 10.1016/j.jbior.2019.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
Mushroom forming basidiomycete Schizophyllum commune has been used as a tractable model organism to study fungal sexual development. Ras signaling activation via G-protein-coupled receptors (GPCRs) has been postulated to play a significant role in the mating and development of S. commune. In this study, a crosstalk between Ras signaling and inositol phosphate signaling by inositol monophosphatase (IMPase) is revealed. Constitutively active Ras1 leads to the repression of IMPase transcription and lithium action on IMPase activity is compensated by the induction of IMPase at transcriptome level. Astonishingly, in S. commune lithium induces a considerable shift to inositol phosphate metabolism leading to a massive increase in the level of higher phosphorylated inositol species up to the inositol pyrophosphates. The lithium induced metabolic changes are not observable in a constitutively active Ras1 mutant. In addition to that, proteome profile helps us to elucidate an overview of lithium action to the broad aspect of fungal metabolism and cellular signaling. Taken together, these findings imply a crosstalk between Ras and inositol phosphate signaling.
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Affiliation(s)
- Reyna Murry
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany
| | - Olaf Kniemeyer
- Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
| | - Katrin Krause
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany
| | - Adolfo Saiardi
- Medical Research Council (MRC) Laboratory for Molecular Cell Biology, Department of Biochemistry and Molecular Biology, University College London, London, UK.
| | - Erika Kothe
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.
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23
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Petkowski JJ, Bains W, Seager S. Natural Products Containing 'Rare' Organophosphorus Functional Groups. Molecules 2019; 24:E866. [PMID: 30823503 PMCID: PMC6429109 DOI: 10.3390/molecules24050866] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/13/2019] [Accepted: 02/22/2019] [Indexed: 12/25/2022] Open
Abstract
Phosphorous-containing molecules are essential constituents of all living cells. While the phosphate functional group is very common in small molecule natural products, nucleic acids, and as chemical modification in protein and peptides, phosphorous can form P⁻N (phosphoramidate), P⁻S (phosphorothioate), and P⁻C (e.g., phosphonate and phosphinate) linkages. While rare, these moieties play critical roles in many processes and in all forms of life. In this review we thoroughly categorize P⁻N, P⁻S, and P⁻C natural organophosphorus compounds. Information on biological source, biological activity, and biosynthesis is included, if known. This review also summarizes the role of phosphorylation on unusual amino acids in proteins (N- and S-phosphorylation) and reviews the natural phosphorothioate (P⁻S) and phosphoramidate (P⁻N) modifications of DNA and nucleotides with an emphasis on their role in the metabolism of the cell. We challenge the commonly held notion that nonphosphate organophosphorus functional groups are an oddity of biochemistry, with no central role in the metabolism of the cell. We postulate that the extent of utilization of some phosphorus groups by life, especially those containing P⁻N bonds, is likely severely underestimated and has been largely overlooked, mainly due to the technological limitations in their detection and analysis.
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Affiliation(s)
- Janusz J Petkowski
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, MA 02139, USA.
| | - William Bains
- Rufus Scientific, 37 The Moor, Melbourn, Royston, Herts SG8 6ED, UK.
| | - Sara Seager
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, MA 02139, USA.
- Department of Physics, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, MA 02139, USA.
- Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Mass. Ave., Cambridge, MA 02139, USA.
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24
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Brehm MA, Klemm U, Rehbach C, Erdmann N, Kolšek K, Lin H, Aponte-Santamaría C, Gräter F, Rauch BH, Riley AM, Mayr GW, Potter BVL, Windhorst S. Inositol hexakisphosphate increases the size of platelet aggregates. Biochem Pharmacol 2018; 161:14-25. [PMID: 30557554 PMCID: PMC6372069 DOI: 10.1016/j.bcp.2018.12.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/13/2018] [Indexed: 12/28/2022]
Abstract
The inositol phosphates, InsP5 and InsP6, have recently been identified as binding partners of fibrinogen, which is critically involved in hemostasis by crosslinking activated platelets at sites of vascular injury. Here, we investigated the putative physiological role of this interaction and found that platelets increase their InsP6 concentration upon stimulation with the PLC-activating agonists thrombin, collagen I and ADP and present a fraction of it at the outer plasma membrane. Cone and plate analysis in whole blood revealed that InsP6 specifically increases platelet aggregate size. This effect is fibrinogen-dependent, since it is inhibited by an antibody that blocks fibrinogen binding to platelets. Furthermore, InsP6 has only an effect on aggregate size of washed platelets when fibrinogen is present, while it has no influence in presence of von Willebrand factor or collagen. By employing blind docking studies we predicted the binding site for InsP6 at the bundle between the γ and β helical subunit of fibrinogen. Since InsP6 is unable to directly activate platelets and it did not exhibit an effect on thrombin formation or fibrin structure, our data indicate that InsP6 might be a hemostatic agent that is produced by platelets upon stimulation with PLC-activating agonists to promote platelet aggregation by supporting crosslinking of fibrinogen and activated platelets.
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Affiliation(s)
- Maria A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrike Klemm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Rehbach
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Nina Erdmann
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Katra Kolšek
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Hongying Lin
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | | | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Bernhard H Rauch
- Institute of Pharmacology, University Medicine Greifswald, Ernst-Moritz-Arndt University, Felix-Hausdorff-Str. 3, 17487 Greifswald, Germany
| | - Andrew M Riley
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Georg W Mayr
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany
| | - Barry V L Potter
- Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Sabine Windhorst
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany.
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25
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Abstract
Inorganic phosphate (Pi) is essential for signal transduction and cell metabolism, and is also an essential structural component of the extracellular matrix of the skeleton. Pi is sensed in bacteria and yeast at the plasma membrane, which activates intracellular signal transduction to control the expression of Pi transporters and other genes that control intracellular Pi levels. In multicellular organisms, Pi homeostasis must be maintained in the organism and at the cellular level, requiring an endocrine and metabolic Pi-sensing mechanism, about which little is currently known. This Review will discuss the metabolic effects of Pi, which are mediated by Pi transporters, inositol pyrophosphates and SYG1-Pho81-XPR1 (SPX)-domain proteins to maintain cellular phosphate homeostasis in the musculoskeletal system. In addition, we will discuss how Pi is sensed by the human body to regulate the production of fibroblast growth factor 23 (FGF23), parathyroid hormone and calcitriol to maintain serum levels of Pi in a narrow range. New findings on the crosstalk between iron and Pi homeostasis in the regulation of FGF23 expression will also be outlined. Mutations in components of these metabolic and endocrine phosphate sensors result in genetic disorders of phosphate homeostasis, cardiomyopathy and familial basal ganglial calcifications, highlighting the importance of this newly emerging area of research.
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Affiliation(s)
- Sampada Chande
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, USA
| | - Clemens Bergwitz
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, USA.
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26
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Negreiros RS, Lander N, Huang G, Cordeiro CD, Smith SA, Morrissey JH, Docampo R. Inorganic polyphosphate interacts with nucleolar and glycosomal proteins in trypanosomatids. Mol Microbiol 2018; 110:973-994. [PMID: 30230089 DOI: 10.1111/mmi.14131] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2018] [Indexed: 12/11/2022]
Abstract
Inorganic polyphosphate (polyP) is a polymer of three to hundreds of phosphate units bound by high-energy phosphoanhydride bonds and present from bacteria to humans. Most polyP in trypanosomatids is concentrated in acidocalcisomes, acidic calcium stores that possess a number of pumps, exchangers, and channels, and are important for their survival. In this work, using polyP as bait we identified > 25 putative protein targets in cell lysates of both Trypanosoma cruzi and Trypanosoma brucei. Gene ontology analysis of the binding partners found a significant over-representation of nucleolar and glycosomal proteins. Using the polyphosphate-binding domain (PPBD) of Escherichia coli exopolyphosphatase (PPX), we localized long-chain polyP to the nucleoli and glycosomes of trypanosomes. A competitive assay based on the pre-incubation of PPBD with exogenous polyP and subsequent immunofluorescence assay of procyclic forms (PCF) of T. brucei showed polyP concentration-dependent and chain length-dependent decrease in the fluorescence signal. Subcellular fractionation experiments confirmed the presence of polyP in glycosomes of T. brucei PCF. Targeting of yeast PPX to the glycosomes of PCF resulted in polyP hydrolysis, alteration in their glycolytic flux and increase in their susceptibility to oxidative stress.
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Affiliation(s)
- Raquel S Negreiros
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Noelia Lander
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Guozhong Huang
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Ciro D Cordeiro
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Stephanie A Smith
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - James H Morrissey
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA.,Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
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27
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Ito M, Fujii N, Wittwer C, Sasaki A, Tanaka M, Bittner T, Jessen HJ, Saiardi A, Takizawa S, Nagata E. Hydrophilic interaction liquid chromatography-tandem mass spectrometry for the quantitative analysis of mammalian-derived inositol poly/pyrophosphates. J Chromatogr A 2018; 1573:87-97. [PMID: 30220429 DOI: 10.1016/j.chroma.2018.08.061] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 08/20/2018] [Accepted: 08/30/2018] [Indexed: 11/25/2022]
Abstract
Although myo-inositol pyrophosphates such as diphosphoinositol pentakisphosphate (InsP7) are important in biology, little quantitative information is available regarding their presence in mammalian organisms owing to the technical difficulties associated with accurately detecting these materials in biological samples. We have developed an analytical method whereby InsP7 and its precursor inositol hexakisphosphate (InsP6) are determined directly and sensitively using tandem mass spectrometry coupled with hydrophilic interaction liquid chromatography (HILIC). InsP6 and InsP7 peak symmetry is influenced greatly by the buffer salt composition and pH of the mobile phase used in HILIC analysis. The use of 300 mM ammonium carbonate (pH 10.5) as an aqueous mobile phase resolves InsP6 and InsP7 on a polymer-based amino HILIC column with minimal peak tailing. Method validation shows that InsP6 and InsP7 can be quantitated from 20-500 pmol with minimal intra-day/inter-day variance in peak area and retention time. The concentration of InsP6 in C57BL/6J mouse brain (40.68 ± 3.84 pmol/mg wet weight) is successfully determined. HILIC‒MS/MS analysis using HEK293 culture cells confirms previous observations that InsP7 is induced by NaF treatment and ectopic expression of InsP6K2, a primary kinase for InsP7 synthesis. Furthermore, this analysis reveals the abundance of InsP6 (50.46 ± 18.57 pmol/106 cells) and scarcity of InsP7 in human blood cells. The results demonstrate that HILIC‒MS/MS analysis can quantitate endogenous InsP6 and InsP7 in mouse and human samples, and we expect that the method will contribute to further understanding of InsP7 functions in mammalian pathobiology.
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Affiliation(s)
- Masatoshi Ito
- Support Center for Medical Research and Education, Tokai University, Isehara, Kanagawa 259‒1193, Japan
| | - Natsuko Fujii
- Department of Neurology, Tokai University School of Medicine, Isehara, Kanagawa 259‒1193, Japan
| | - Christopher Wittwer
- Institute of Organic Chemistry, University of Freiburg, 79104 Freiburg, Germany
| | - Ayumi Sasaki
- Support Center for Medical Research and Education, Tokai University, Isehara, Kanagawa 259‒1193, Japan
| | - Masayuki Tanaka
- Support Center for Medical Research and Education, Tokai University, Isehara, Kanagawa 259‒1193, Japan
| | - Tamara Bittner
- Institute of Organic Chemistry, University of Freiburg, 79104 Freiburg, Germany
| | - Henning J Jessen
- Institute of Organic Chemistry, University of Freiburg, 79104 Freiburg, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, and Department of Cell and Developmental Biology, University College London, WC1E 6BT, United Kingdom
| | - Shunya Takizawa
- Department of Neurology, Tokai University School of Medicine, Isehara, Kanagawa 259‒1193, Japan
| | - Eiichiro Nagata
- Department of Neurology, Tokai University School of Medicine, Isehara, Kanagawa 259‒1193, Japan.
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28
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Becker RA, Cluff K, Duraisamy N, Mehraein H, Farhoud H, Collins T, Casale GP, Pipinos II, Subbiah J. Optical probing of gastrocnemius in patients with peripheral artery disease characterizes myopathic biochemical alterations and correlates with stage of disease. Physiol Rep 2017; 5:5/5/e13161. [PMID: 28292886 PMCID: PMC5350172 DOI: 10.14814/phy2.13161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 01/16/2017] [Indexed: 01/15/2023] Open
Abstract
Peripheral artery disease (PAD) is a condition caused by atherosclerotic blockages in the arteries supplying the lower limbs and is characterized by ischemia of the leg, progressive myopathy, and increased risk of limb loss. The affected leg muscles undergo significant changes of their biochemistry and metabolism including variations in the levels of many key proteins, lipids, and nucleotides. The mechanisms behind these changes are poorly understood. The objective of this study was to correlate the severity of the PAD disease stage and associated hemodynamic limitation (determined by the ankle brachial index, ABI) in the legs of the patients with alterations in the biochemistry of chronically ischemic leg muscle as determined by ATR‐Fourier transform infrared micro‐spectroscopy. Muscle (gastrocnemius) biopsies were collected from 13 subjects including four control patients (ABI≥0.9), five claudicating patients (0.4 ≤ ABI<0.9), and four critical limb ischemia (CLI) patients (ABI<0.4). Slide mounted specimens were analyzed by ATR‐Fourier transform infrared micro‐spectroscopy. An analysis of variance and a partial least squares regression model were used to identify significant differences in spectral peaks and correlate them with the ABI. The spectra revealed significant differences (P < 0.05) across control, claudicating, and CLI patients in the fingerprint and functional group regions. Infrared microspectroscopic probing of ischemic muscle biopsies demonstrates that PAD produces significant and unique changes to muscle biochemistry in comparison to control specimens. These distinctive biochemical profiles correlate with disease progression and may provide insight and direction for new targets in the diagnosis and therapy of muscle degeneration in PAD.
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Affiliation(s)
- Ryan A Becker
- Biomedical Engineering Department, Wichita State University, Wichita, Kansas
| | - Kim Cluff
- Biomedical Engineering Department, Wichita State University, Wichita, Kansas
| | | | - Hootan Mehraein
- Biomedical Engineering Department, Wichita State University, Wichita, Kansas.,Industrial Engineering, Wichita State University, Wichita, Kansas
| | | | - Tracie Collins
- Department of Preventive Medicine & Public Health, School of Medicine, University of Kansas Medical Center, Wichita, Kansas
| | - George P Casale
- Division of General Surgery, Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska
| | - Iraklis I Pipinos
- Division of General Surgery, Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska.,Department of Surgery and VA Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Jeyamkondan Subbiah
- Biological Systems Engineering and Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska
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29
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Shah A, Ganguli S, Sen J, Bhandari R. Inositol Pyrophosphates: Energetic, Omnipresent and Versatile Signalling Molecules. J Indian Inst Sci 2017; 97:23-40. [PMID: 32214696 PMCID: PMC7081659 DOI: 10.1007/s41745-016-0011-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 11/16/2016] [Indexed: 12/21/2022]
Abstract
Inositol pyrophosphates (PP-IPs) are a class of energy-rich signalling molecules found in all eukaryotic cells. These are derivatives of inositol that contain one or more diphosphate (or pyrophosphate) groups in addition to monophosphates. The more abundant and best studied PP-IPs are diphosphoinositol pentakisphosphate (IP7) and bis-diphosphoinositol tetrakisphosphate (IP8). These molecules can influence protein function by two mechanisms: binding and pyrophosphorylation. The former involves the specific interaction of a particular inositol pyrophosphate with a binding site on a protein, while the latter is a unique attribute of inositol pyrophosphates, wherein the β-phosphate moiety is transferred from a PP-IP to a pre-phosphorylated serine residue in a protein to generate pyrophosphoserine. Both these events can result in changes in the target protein’s activity, localisation or its interaction with other partners. As a consequence of their ubiquitous presence in all eukaryotic organisms and all cell types examined till date, and their ability to modify protein function, PP-IPs have been found to participate in a wide range of metabolic, developmental, and signalling pathways. This review highlights
many of the known functions of PP-IPs in the context of their temporal and spatial distribution in eukaryotic cells.
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Affiliation(s)
- Akruti Shah
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
- Graduate Studies, Manipal University, Manipal, Karnataka India
| | - Shubhra Ganguli
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
- Graduate Studies, Manipal University, Manipal, Karnataka India
| | - Jayraj Sen
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
- Graduate Studies, Manipal University, Manipal, Karnataka India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana India
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30
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Gu C, Nguyen HN, Hofer A, Jessen HJ, Dai X, Wang H, Shears SB. The Significance of the Bifunctional Kinase/Phosphatase Activities of Diphosphoinositol Pentakisphosphate Kinases (PPIP5Ks) for Coupling Inositol Pyrophosphate Cell Signaling to Cellular Phosphate Homeostasis. J Biol Chem 2017; 292:4544-4555. [PMID: 28126903 PMCID: PMC5377771 DOI: 10.1074/jbc.m116.765743] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/25/2017] [Indexed: 12/31/2022] Open
Abstract
Proteins responsible for Pi homeostasis are critical for all life. In Saccharomyces cerevisiae, extracellular [Pi] is "sensed" by the inositol-hexakisphosphate kinase (IP6K) that synthesizes the intracellular inositol pyrophosphate 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) as follows: during a period of Pi starvation, there is a decline in cellular [ATP]; the unusually low affinity of IP6Ks for ATP compels 5-InsP7 levels to fall in parallel (Azevedo, C., and Saiardi, A. (2017) Trends. Biochem. Sci. 42, 219-231. Hitherto, such Pi sensing has not been documented in metazoans. Here, using a human intestinal epithelial cell line (HCT116), we show that levels of both 5-InsP7 and ATP decrease upon [Pi] starvation and subsequently recover during Pi replenishment. However, a separate inositol pyrophosphate, 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8), reacts more dramatically (i.e. with a wider dynamic range and greater sensitivity). To understand this novel InsP8 response, we characterized kinetic properties of the bifunctional 5-InsP7 kinase/InsP8 phosphatase activities of full-length diphosphoinositol pentakisphosphate kinases (PPIP5Ks). These data fulfil previously published criteria for any bifunctional kinase/phosphatase to exhibit concentration robustness, permitting levels of the kinase product (InsP8 in this case) to fluctuate independently of varying precursor (i.e. 5-InsP7) pool size. Moreover, we report that InsP8 phosphatase activities of PPIP5Ks are strongly inhibited by Pi (40-90% within the 0-1 mm range). For PPIP5K2, Pi sensing by InsP8 is amplified by a 2-fold activation of 5-InsP7 kinase activity by Pi within the 0-5 mm range. Overall, our data reveal mechanisms that can contribute to specificity in inositol pyrophosphate signaling, regulating InsP8 turnover independently of 5-InsP7, in response to fluctuations in extracellular supply of a key nutrient.
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Affiliation(s)
- Chunfang Gu
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Hoai-Nghia Nguyen
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Alexandre Hofer
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Henning J Jessen
- Institute of Organic Chemistry, Albert Ludwigs University, Albertstrasse 21, 79104 Freiburg, Germany, and
| | - Xuming Dai
- Division of Cardiology, McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Huanchen Wang
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Stephen B Shears
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709,
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31
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Shears SB, Baughman BM, Gu C, Nair VS, Wang H. The significance of the 1-kinase/1-phosphatase activities of the PPIP5K family. Adv Biol Regul 2016; 63:98-106. [PMID: 27776974 DOI: 10.1016/j.jbior.2016.10.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 10/13/2016] [Accepted: 10/15/2016] [Indexed: 01/29/2023]
Abstract
The inositol pyrophosphates (diphosphoinositol polyphosphates), which include 1-InsP7, 5-InsP7, and InsP8, are highly 'energetic' signaling molecules that play important roles in many cellular processes, particularly with regards to phosphate and bioenergetic homeostasis. Two classes of kinases synthesize the PP-InsPs: IP6Ks and PPIP5Ks. The significance of the IP6Ks - and their 5-InsP7 product - has been widely reported. However, relatively little is known about the biological significance of the PPIP5Ks. The purpose of this review is to provide an update on developments in our understanding of key features of the PPIP5Ks, which we believe strengthens the hypothesis that their catalytic activities serve important cellular functions. Central to this discussion is the recent discovery that the PPIP5K is a rare example of a single protein that catalyzes a kinase/phosphatase futile cycle.
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Affiliation(s)
- Stephen B Shears
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA.
| | - Brandi M Baughman
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| | - Chunfang Gu
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| | - Vasudha S Nair
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
| | - Huanchen Wang
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, 101 T.W. Alexander Drive, Research Triangle Park, NC, 27709, USA
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32
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Suess PM, Gomer RH. Extracellular Polyphosphate Inhibits Proliferation in an Autocrine Negative Feedback Loop in Dictyostelium discoideum. J Biol Chem 2016; 291:20260-9. [PMID: 27519410 DOI: 10.1074/jbc.m116.737825] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Indexed: 11/06/2022] Open
Abstract
Polyphosphate is a polymer of phosphate residues linked by high energy phosphoanhydride bonds. Despite being highly conserved throughout nature, its function is poorly understood. Here we show that Dictyostelium cells accumulate extracellular polyphosphate, and this acts to inhibit proliferation at high cell densities. In shaking culture, extracellular polyphosphate concentrations increase as cell density increases, and if the concentration of polyphosphate observed at the stationary phase is added to cells at mid-log, proliferation is halted. Adding an exopolyphosphatase to cell cultures or stationary phase conditioned medium decreases polyphosphate levels and abrogates the anti-proliferative effect. The cells show saturable binding of polyphosphate, suggesting the presence of a cell surface polyphosphate receptor. Extracellular polyphosphate accumulation is potentiated by decreased nutrient levels, potentially as a means to anticipate starvation. Loss of the Dictyostelium polyphosphate kinase DdPpk1 causes intracellular polyphosphate levels to become undetectable and negatively affects fitness, cytokinesis, and germination. However, cells lacking DdPpk1 accumulate ∼50% normal levels of extracellular polyphosphate, suggesting an additional means of synthesis. We found that cells lacking inositol hexakisphosphate kinase, which is responsible for the synthesis of the inositol pyrophosphates IP7 and IP8, reach abnormally high cell densities and show decreased extracellular polyphosphate levels. Two different enzymes thus appear to mediate the synthesis of Dictyostelium extracellular polyphosphate, which is used as a signal in an autocrine negative feedback loop to regulate cell proliferation.
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Affiliation(s)
- Patrick M Suess
- From the Department of Biology, Texas A&M University, College Station, Texas 77843-3474
| | - Richard H Gomer
- From the Department of Biology, Texas A&M University, College Station, Texas 77843-3474
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33
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Thota SG, Bhandari R. The emerging roles of inositol pyrophosphates in eukaryotic cell physiology. J Biosci 2016; 40:593-605. [PMID: 26333405 DOI: 10.1007/s12038-015-9549-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inositol pyrophosphates are water soluble derivatives of inositol that contain pyrophosphate or diphosphate moieties in addition to monophosphates. The best characterised inositol pyrophosphates, are IP7 (diphosphoinositol pentakisphosphate or PP-IP5), and IP8 (bisdiphosphoinositol tetrakisphosphate or (PP)2-IP4). These energy-rich small molecules are present in all eukaryotic cells, from yeast to mammals, and are involved in a wide range of cellular functions including apoptosis, vesicle trafficking, DNA repair, osmoregulation, phosphate homeostasis, insulin sensitivity, immune signalling, cell cycle regulation, and ribosome synthesis. Identified more than 20 years ago, there is still only a rudimentary understanding of the mechanisms by which inositol pyrophosphates participate in these myriad pathways governing cell physiology and homeostasis. The unique stereochemical and bioenergetic properties these molecules possess as a consequence of the presence of one or two pyrophosphate moieties in the vicinity of densely packed monophosphates are likely to form the molecular basis for their participation in multiple signalling and metabolic pathways. The aim of this review is to provide first time researchers in this area with an introduction to inositol pyrophosphates and a comprehensive overview on their cellular functions.
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Affiliation(s)
- Swarna Gowri Thota
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500 001, India
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34
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Abstract
Eukaryotic cells have ubiquitously utilized the myo-inositol backbone to generate a diverse array of signalling molecules. This is achieved by arranging phosphate groups around the six-carbon inositol ring. There is virtually no biological process that does not take advantage of the uniquely variable architecture of phosphorylated inositol. In inositol biology, phosphates are able to form three distinct covalent bonds: phosphoester, phosphodiester and phosphoanhydride bonds, with each providing different properties. The phosphoester bond links phosphate groups to the inositol ring, the variable arrangement of which forms the basis of the signalling capacity of the inositol phosphates. Phosphate groups can also form the structural bridge between myo-inositol and diacylglycerol through the phosphodiester bond. The resulting lipid-bound inositol phosphates, or phosphoinositides, further expand the signalling potential of this family of molecules. Finally, inositol is also notable for its ability to host more phosphates than it has carbons. These unusual organic molecules are commonly referred to as the inositol pyrophosphates (PP-IPs), due to the presence of high-energy phosphoanhydride bonds (pyro- or diphospho-). PP-IPs themselves constitute a varied family of molecules with one or more pyrophosphate moiety/ies located around the inositol. Considering the relationship between phosphate and inositol, it is no surprise that members of the inositol phosphate family also regulate cellular phosphate homoeostasis. Notably, the PP-IPs play a fundamental role in controlling the metabolism of the ancient polymeric form of phosphate, inorganic polyphosphate (polyP). Here we explore the intimate links between phosphate, inositol phosphates and polyP, speculating on the evolution of these relationships.
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Thomas MP, Mills SJ, Potter BVL. The "Other" Inositols and Their Phosphates: Synthesis, Biology, and Medicine (with Recent Advances in myo-Inositol Chemistry). Angew Chem Int Ed Engl 2016; 55:1614-50. [PMID: 26694856 PMCID: PMC5156312 DOI: 10.1002/anie.201502227] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 12/24/2022]
Abstract
Cell signaling via inositol phosphates, in particular via the second messenger myo-inositol 1,4,5-trisphosphate, and phosphoinositides comprises a huge field of biology. Of the nine 1,2,3,4,5,6-cyclohexanehexol isomers, myo-inositol is pre-eminent, with "other" inositols (cis-, epi-, allo-, muco-, neo-, L-chiro-, D-chiro-, and scyllo-) and derivatives rarer or thought not to exist in nature. However, neo- and d-chiro-inositol hexakisphosphates were recently revealed in both terrestrial and aquatic ecosystems, thus highlighting the paucity of knowledge of the origins and potential biological functions of such stereoisomers, a prevalent group of environmental organic phosphates, and their parent inositols. Some "other" inositols are medically relevant, for example, scyllo-inositol (neurodegenerative diseases) and d-chiro-inositol (diabetes). It is timely to consider exploration of the roles and applications of the "other" isomers and their derivatives, likely by exploiting techniques now well developed for the myo series.
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Affiliation(s)
- Mark P Thomas
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Stephen J Mills
- Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Barry V L Potter
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, OX1 3QT, UK.
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Thomas MP, Mills SJ, Potter BVL. Die “anderen” Inositole und ihre Phosphate: Synthese, Biologie und Medizin (sowie jüngste Fortschritte in dermyo-Inositolchemie). Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mark P. Thomas
- Department of Pharmacy & Pharmacology; University of Bath; Claverton Down Bath BA2 7AY Vereinigtes Königreich
| | - Stephen J. Mills
- Department of Pharmacy & Pharmacology; University of Bath; Claverton Down Bath BA2 7AY Vereinigtes Königreich
| | - Barry V. L. Potter
- Department of Pharmacology; University of Oxford; Mansfield Road Oxford OX1 3QT Vereinigtes Königreich
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Azevedo C, Saiardi A. Why always lysine? The ongoing tale of one of the most modified amino acids. Adv Biol Regul 2015; 60:144-150. [PMID: 26482291 DOI: 10.1016/j.jbior.2015.09.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 09/30/2015] [Accepted: 09/30/2015] [Indexed: 11/26/2022]
Abstract
The complex physiology of living organisms must be finely-tuned to permit the flexibility required to respond to the changing environment. Evolution has provided an interconnected and intricate array of regulatory mechanisms to facilitate this fine-tuning. The number of genes cannot alone explain the complexity of these mechanisms. Rather, signalling is regulated at multiple levels, from genomic to transcriptional, translational and post-translational. Post-translational modification (PTM) of proteins offers an additional level of regulation after protein synthesis that allows a rapid, controlled and reversible response to environmental cues. Many amino acid side chains are post-translationally modified. These modifications can either be enzymatic, such as the phosphorylation of serine, threonine and tyrosine residues, or non-enzymatic, such as the nitrosylation of cysteine residues. Strikingly, lysine residues are targeted by a particularly high number of PTMs including acetylation, methylation, ubiquitination and sumoylation. Additionally, lysines have recently been identified as the target of the non-enzymatic PTM polyphosphorylation. This novel PTM sees linear chains of inorganic polyphosphates (polyP) covalently attached to lysine residues. Interestingly, polyphosphorylation is indirectly dependent on inositol pyrophosphates, a class of cellular messengers. The attachment of polyP to lysine occurs through the phosphoramidate bond, which, unlike the phosphester bond, is unstable under the conditions used in common mass spectroscopy. This characteristic, together with the diversity of lysine PTMs, suggests that many other lysine modifications may still remain unidentified, raising the intriguing possibility that lysine PTMs may be the major means by which signalling pathways modify protein behaviour.
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Affiliation(s)
- Cristina Azevedo
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK.
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT, UK.
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Kolozsvari B, Firth S, Saiardi A. Raman spectroscopy detection of phytic acid in plant seeds reveals the absence of inorganic polyphosphate. MOLECULAR PLANT 2015; 8:826-828. [PMID: 25620771 DOI: 10.1016/j.molp.2015.01.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 06/04/2023]
Affiliation(s)
- Bernadett Kolozsvari
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Steven Firth
- Department of Chemistry, University College London, London WC1H 0AJ, UK
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
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39
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Azevedo C, Livermore T, Saiardi A. Protein Polyphosphorylation of Lysine Residues by Inorganic Polyphosphate. Mol Cell 2015; 58:71-82. [DOI: 10.1016/j.molcel.2015.02.010] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 12/02/2014] [Accepted: 02/03/2015] [Indexed: 10/23/2022]
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Williams SP, Gillaspy GE, Perera IY. Biosynthesis and possible functions of inositol pyrophosphates in plants. FRONTIERS IN PLANT SCIENCE 2015; 6:67. [PMID: 25729385 PMCID: PMC4325660 DOI: 10.3389/fpls.2015.00067] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/26/2015] [Indexed: 05/24/2023]
Abstract
Inositol phosphates (InsPs) are intricately tied to lipid signaling, as at least one portion of the inositol phosphate signaling pool is derived from hydrolysis of the lipid precursor, phosphatidyl inositol (4,5) bisphosphate. The focus of this review is on the inositol pyrophosphates, which are a novel group of InsP signaling molecules containing diphosphate or triphosphate chains (i.e., PPx) attached to the inositol ring. These PPx-InsPs are emerging as critical players in the integration of cellular metabolism and stress signaling in non-plant eukaryotes. Most eukaryotes synthesize the precursor molecule, myo-inositol (1,2,3,4,5,6)-hexakisphosphate (InsP6), which can serve as a signaling molecule or as storage compound of inositol, phosphorus, and minerals (referred to as phytic acid). Even though plants produce huge amounts of precursor InsP6 in seeds, almost no attention has been paid to whether PPx-InsPs exist in plants, and if so, what roles these molecules play. Recent work has delineated that Arabidopsis has two genes capable of PP-InsP5 synthesis, and PPx-InsPs have been detected across the plant kingdom. This review will detail the known roles of PPx-InsPs in yeast and animal systems, and provide a description of recent data on the synthesis and accumulation of these novel molecules in plants, and potential roles in signaling.
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Affiliation(s)
- Sarah P. Williams
- Biochemistry, Virginia Polytechnic and State UniversityBlacksburg, VA, USA
| | - Glenda E. Gillaspy
- Biochemistry, Virginia Polytechnic and State UniversityBlacksburg, VA, USA
| | - Imara Y. Perera
- Plant and Microbial Biology, North Carolina State UniversityRaleigh, NC, USA
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Shears SB. Inositol pyrophosphates: why so many phosphates? Adv Biol Regul 2014; 57:203-16. [PMID: 25453220 DOI: 10.1016/j.jbior.2014.09.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 09/23/2014] [Accepted: 09/25/2014] [Indexed: 10/24/2022]
Abstract
The inositol pyrophosphates (PP-InsPs) are a specialized group of "energetic" signaling molecules found in yeasts, plants and animals. PP-InsPs boast the most crowded three dimensional phosphate arrays found in Nature; multiple phosphates and diphosphates are crammed around the six-carbon, inositol ring. Yet, phosphate esters are also a major energy currency in cells. So the synthesis of PP-InsPs, and the maintenance of their levels in the face of a high rate of ongoing turnover, all requires significant bioenergetic input. What are the particular properties of PP-InsPs that repay this investment of cellular energy? Potential answers to that question are discussed here, against the backdrop of a recent hypothesis that signaling by PP-InsPs is evolutionarily ancient. The latter idea is extended herein, with the proposal that the primordial origins of PP-InsPs is reflected in the apparent lack of isomeric specificity of certain of their actions. Nevertheless, there are other aspects of signaling by these polyphosphates that are more selective for a particular PP-InsP isomer. Consideration of the nature of both specific and non-specific effects of PP-InsPs can help rationalize why such molecules possess so many phosphates.
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Affiliation(s)
- Stephen B Shears
- Inositol Signaling Group, Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, NIH, DHHS, PO Box 12233, Research Triangle Park, NC 27709, USA.
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42
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Functions of inorganic polyphosphates in eukaryotic cells: a coat of many colours. Biochem Soc Trans 2014; 42:98-102. [PMID: 24450634 DOI: 10.1042/bst20130111] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PolyP (inorganic polyphosphate) is a linear polymer of tens to hundreds of orthophosphate residues linked by high-energy phosphoanhydride bonds. This polymer is present in all living organisms from bacteria to mammals. Until recently, most of the studies on polyP have focused on its function in prokaryotes. In prokaryotes, polyP has been implicated in many unrelated processes ranging from basic metabolism to structural functions. However, polyP analysis and function in higher eukaryotes has been gaining momentum recently. In the present review, we mainly aim to discuss the proposed intracellular functions of polyP in higher eukaryotes and its detection methods.
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43
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Pisani F, Livermore T, Rose G, Chubb JR, Gaspari M, Saiardi A. Analysis of Dictyostelium discoideum inositol pyrophosphate metabolism by gel electrophoresis. PLoS One 2014; 9:e85533. [PMID: 24416420 PMCID: PMC3887064 DOI: 10.1371/journal.pone.0085533] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/28/2013] [Indexed: 11/28/2022] Open
Abstract
The social amoeba Dictyostelium discoideum was instrumental in the discovery and early characterization of inositol pyrophosphates, a class of molecules possessing highly-energetic pyrophosphate bonds. Inositol pyrophosphates regulate diverse biological processes and are attracting attention due to their ability to control energy metabolism and insulin signalling. However, inositol pyrophosphate research has been hampered by the lack of simple experimental procedures to study them. The recent development of polyacrylamide gel electrophoresis (PAGE) and simple staining to resolve and detect inositol pyrophosphate species has opened new investigative possibilities. This technology is now commonly applied to study in vitro enzymatic reactions. Here we employ PAGE technology to characterize the D. discoideum inositol pyrophosphate metabolism. Surprisingly, only three major bands are detectable after resolving acidic extract on PAGE. We have demonstrated that these three bands correspond to inositol hexakisphosphate (IP6 or Phytic acid) and its derivative inositol pyrophosphates, IP7 and IP8. Biochemical analyses and genetic evidence were used to establish the genuine inositol phosphate nature of these bands. We also identified IP9 in D. discoideum cells, a molecule so far detected only from in vitro biochemical reactions. Furthermore, we discovered that this amoeba possesses three different inositol pentakisphosphates (IP5) isomers, which are largely metabolised to inositol pyrophosphates. Comparison of PAGE with traditional Sax-HPLC revealed an underestimation of the cellular abundance of inositol pyrophosphates by traditional methods. In fact our study revealed much higher levels of inositol pyrophosphates in D. discoideum in the vegetative state than previously detected. A three-fold increase in IP8 was observed during development of D. discoideum a value lower that previously reported. Analysis of inositol pyrophosphate metabolism using ip6k null amoeba revealed the absence of developmentally-induced synthesis of inositol pyrophosphates, suggesting that the alternative class of enzyme responsible for pyrophosphate synthesis, PP-IP5K, doesn’t’ play a major role in the IP8 developmental increase.
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Affiliation(s)
- Francesca Pisani
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- Department of Biology, Ecology and Earth Science, University of Calabria, Rende, Italy
| | - Thomas Livermore
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Giuseppina Rose
- Department of Biology, Ecology and Earth Science, University of Calabria, Rende, Italy
| | - Jonathan Robert Chubb
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Marco Gaspari
- Laboratory of Proteomics and Mass Spectrometry, Department of Experimental and Clinical Medicine, “Magna Græcia” University of Catanzaro, Catanzaro, Italy
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
- * E-mail:
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44
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Abstract
In this issue of Blood, Ghosh and colleagues report that knocking out an inositol kinase in mice diminishes polyphosphate in platelet dense granules, thereby reducing hemostasis and protecting against thrombosis.
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45
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Thomas MP, Potter BVL. The enzymes of human diphosphoinositol polyphosphate metabolism. FEBS J 2013; 281:14-33. [PMID: 24152294 PMCID: PMC4063336 DOI: 10.1111/febs.12575] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/10/2013] [Accepted: 10/15/2013] [Indexed: 12/22/2022]
Abstract
Diphospho-myo-inositol polyphosphates have many roles to play, including roles in apoptosis, vesicle trafficking, the response of cells to stress, the regulation of telomere length and DNA damage repair, and inhibition of the cyclin-dependent kinase Pho85 system that monitors phosphate levels. This review focuses on the three classes of enzymes involved in the metabolism of these compounds: inositol hexakisphosphate kinases, inositol hexakisphosphate and diphosphoinositol-pentakisphosphate kinases and diphosphoinositol polyphosphate phosphohydrolases. However, these enzymes have roles beyond being mere catalysts, and their interactions with other proteins have cellular consequences. Through their interactions, the three inositol hexakisphosphate kinases have roles in exocytosis, diabetes, the response to infection, and apoptosis. The two inositol hexakisphosphate and diphosphoinositol-pentakisphosphate kinases influence the cellular response to phosphatidylinositol (3,4,5)-trisphosphate and the migration of pleckstrin homology domain-containing proteins to the plasma membrane. The five diphosphoinositol polyphosphate phosphohydrolases interact with ribosomal proteins and transcription factors, as well as proteins involved in membrane trafficking, exocytosis, ubiquitination and the proteasomal degradation of target proteins. Possible directions for future research aiming to determine the roles of these enzymes are highlighted.
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Affiliation(s)
- Mark P Thomas
- Department of Pharmacy & Pharmacology, University of Bath, UK
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46
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Abstract
Epigenetic modifications of chromatin represent a fundamental mechanism by which eukaryotic cells adapt their transcriptional response to developmental and environmental cues. Although an increasing number of molecules have been linked to epigenetic changes, the intracellular pathways that lead to their activation/repression have just begun to be characterized. Here, we demonstrate that inositol hexakisphosphate kinase 1 (IP6K1), the enzyme responsible for the synthesis of the high-energy inositol pyrophosphates (IP7), is associated with chromatin and interacts with Jumonji domain containing 2C (JMJD2C), a recently identified histone lysine demethylase. Reducing IP6K1 levels by RNAi or using mouse embryonic fibroblasts derived from ip6k1(-/-) knockout mice results in a decreased IP7 concentration that epigenetically translates to reduced levels of trimethyl-histone H3 lysine 9 (H3K9me3) and increased levels of acetyl-H3K9. Conversely, expression of IP6K1 induces JMJD2C dissociation from chromatin and increases H3K9me3 levels, which depend on IP6K1 catalytic activity. Importantly, these effects lead to changes in JMJD2C-target gene transcription. Our findings demonstrate that inositol pyrophosphate signaling influences nuclear functions by regulating histone modifications.
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47
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Shah ZH, Jones DR, Sommer L, Foulger R, Bultsma Y, D'Santos C, Divecha N. Nuclear phosphoinositides and their impact on nuclear functions. FEBS J 2013; 280:6295-310. [PMID: 24112514 DOI: 10.1111/febs.12543] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/11/2013] [Accepted: 09/16/2013] [Indexed: 12/23/2022]
Abstract
Polyphosphoinositides (PPIn) are important lipid molecules whose levels are de-regulated in human diseases such as cancer, neurodegenerative disorders and metabolic syndromes. PPIn are synthesized and degraded by an array of kinases, phosphatases and lipases which are localized to various subcellular compartments and are subject to regulation in response to both extra- and intracellular cues. Changes in the activities of enzymes that metabolize PPIn lead to changes in the profiles of PPIn in various subcellular compartments. Understanding how subcellular PPIn are regulated and how they affect downstream signaling is critical to understanding their roles in human diseases. PPIn are present in the nucleus, and their levels are changed in response to various stimuli, suggesting that they may serve to regulate specific nuclear functions. However, the lack of nuclear downstream targets has hindered the definition of which pathways nuclear PPIn affect. Over recent years, targeted and global proteomic studies have identified a plethora of potential PPIn-interacting proteins involved in many aspects of transcription, chromatin remodelling and mRNA maturation, suggesting that PPIn signalling within the nucleus represents a largely unexplored novel layer of complexity in the regulation of nuclear functions.
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Affiliation(s)
- Zahid H Shah
- Cancer Research UK Inositide Laboratory, Paterson Institute for Cancer Research, Manchester, UK
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48
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Inositol hexakisphosphate kinase 1 maintains hemostasis in mice by regulating platelet polyphosphate levels. Blood 2013; 122:1478-86. [PMID: 23782934 DOI: 10.1182/blood-2013-01-481549] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Polyphosphate (polyP), a polymer of orthophosphate moieties released from the dense granules of activated platelets, is a procoagulant agent. Inositol pyrophosphates, another group of phosphate-rich molecules, consist of mono- and diphosphates substituted on an inositol ring. Diphosphoinositol pentakisphosphate (IP7), the most abundant inositol pyrophosphate, is synthesized on phosphorylation of inositol hexakisphosphate (IP6) by IP6 kinases, of which there are 3 mammalian isoforms (IP6K1/2/3) and a single yeast isoform. Yeast lacking IP6 kinase are devoid of polyP, suggesting a role for IP6 kinase in maintaining polyP levels. We theorized that the molecular link between IP6 kinase and polyP is conserved in mammals and investigated whether polyP-dependent platelet function is altered in IP6K1 knockout (Ip6k1(-/-)) mice. We observe a significant reduction in platelet polyP levels in Ip6k1(-/-) mice, along with slower platelet aggregation and lengthened plasma clotting time. Incorporation of polyP into fibrin clots was reduced in Ip6k1(-/-) mice, thereby altering clot ultrastructure, which was rescued on the addition of exogenous polyP. In vivo assays revealed longer tail bleeding time and resistance to thromboembolism in Ip6k1(-/-) mice. Taken together, our data suggest a novel role for IP6K1 in regulation of mammalian hemostasis via its control of platelet polyP levels.
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49
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Abstract
The present review will explore the insights gained into inositol pyrophosphates in the 20 years since their discovery in 1993. These molecules are defined by the presence of the characteristic ‘high energy’ pyrophosphate moiety and can be found ubiquitously in eukaryotic cells. The enzymes that synthesize them are similarly well distributed and can be found encoded in any eukaryote genome. Rapid progress has been made in characterizing inositol pyrophosphate metabolism and they have been linked to a surprisingly diverse range of cellular functions. Two decades of work is now beginning to present a view of inositol pyrophosphates as fundamental, conserved and highly important agents in the regulation of cellular homoeostasis. In particular it is emerging that energy metabolism, and thus ATP production, is closely regulated by these molecules. Much of the early work on these molecules was performed in the yeast Saccharomyces cerevisiae and the social amoeba Dictyostelium discoideum, but the development of mouse knockouts for IP6K1 and IP6K2 [IP6K is IP6 (inositol hexakisphosphate) kinase] in the last 5 years has provided very welcome tools to better understand the physiological roles of inositol pyrophosphates. Another recent innovation has been the use of gel electrophoresis to detect and purify inositol pyrophosphates. Despite the advances that have been made, many aspects of inositol pyrophosphate biology remain far from clear. By evaluating the literature, the present review hopes to promote further research in this absorbing area of biology.
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Bosch D, Saiardi A. Arginine transcriptional response does not require inositol phosphate synthesis. J Biol Chem 2012; 287:38347-55. [PMID: 22992733 PMCID: PMC3488103 DOI: 10.1074/jbc.m112.384255] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 09/17/2012] [Indexed: 12/25/2022] Open
Abstract
Inositol phosphates are key signaling molecules affecting a large variety of cellular processes. Inositol-polyphosphate multikinase (IPMK) is a central component of the inositol phosphate biosynthetic routes, playing essential roles during development. IPMK phosphorylates inositol 1,4,5-trisphosphate to inositol tetrakisphosphate and subsequently to inositol pentakisphosphate and has also been described to function as a lipid kinase. Recently, a catalytically inactive mammalian IPMK was reported to be involved in nutrient signaling by way of mammalian target of rapamycin and AMP-activated protein kinase. In yeast, the IPMK homologue, Arg82, is the sole inositol-trisphosphate kinase. Arg82 has been extensively studied as part of the transcriptional complex regulating nitrogen sensing, in particular arginine metabolism. Whether this role requires Arg82 catalytic activity has long been a matter of contention. In this study, we developed a novel method for the real time study of promoter strength in vivo and used it to demonstrate that catalytically inactive Arg82 fully restored the arginine-dependent transcriptional response. We also showed that expression in yeast of catalytically active, but structurally very different, mammalian or plant IPMK homologue failed to restore arginine regulation. Our work indicates that inositol phosphates do not regulate arginine-dependent gene expression.
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Affiliation(s)
- Daniel Bosch
- From the Cell Biology Unit, Medical Research Council Laboratory for Molecular Cell Biology, and Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Adolfo Saiardi
- From the Cell Biology Unit, Medical Research Council Laboratory for Molecular Cell Biology, and Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
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