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Phospholipids and inositol phosphates linked to the epigenome. Histochem Cell Biol 2018; 150:245-253. [DOI: 10.1007/s00418-018-1690-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2018] [Indexed: 12/17/2022]
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Chakraborty A. The inositol pyrophosphate pathway in health and diseases. Biol Rev Camb Philos Soc 2018; 93:1203-1227. [PMID: 29282838 PMCID: PMC6383672 DOI: 10.1111/brv.12392] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 11/28/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022]
Abstract
Inositol pyrophosphates (IPPs) are present in organisms ranging from plants, slime moulds and fungi to mammals. Distinct classes of kinases generate different forms of energetic diphosphate-containing IPPs from inositol phosphates (IPs). Conversely, polyphosphate phosphohydrolase enzymes dephosphorylate IPPs to regenerate the respective IPs. IPPs and/or their metabolizing enzymes regulate various cell biological processes by modulating many proteins via diverse mechanisms. In the last decade, extensive research has been conducted in mammalian systems, particularly in knockout mouse models of relevant enzymes. Results obtained from these studies suggest impacts of the IPP pathway on organ development, especially of brain and testis. Conversely, deletion of specific enzymes in the pathway protects mice from various diseases such as diet-induced obesity (DIO), type-2 diabetes (T2D), fatty liver, bacterial infection, thromboembolism, cancer metastasis and aging. Furthermore, pharmacological inhibition of the same class of enzymes in mice validates the therapeutic importance of this pathway in cardio-metabolic diseases. This review critically analyses these findings and summarizes the significance of the IPP pathway in mammalian health and diseases. It also evaluates benefits and risks of targeting this pathway in disease therapies. Finally, future directions of mammalian IPP research are discussed.
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Affiliation(s)
- Anutosh Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO 63104, U.S.A
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53
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Al-Anbaky Q, Al-Karakooly Z, Connor R, Williams L, Yarbrough A, Bush J, Ali N. Role of inositol polyphosphates in programed cell death in Dictyostelium discoideum and its developmental life cycle. Mol Cell Biochem 2018; 449:237-250. [PMID: 29679279 DOI: 10.1007/s11010-018-3360-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 04/16/2018] [Indexed: 11/28/2022]
Abstract
Programed cell death or apoptosis is a key developmental process that maintains tissue homeostasis in multicellular organisms. Inositol polyphosphates (InsPs) are key signaling molecules known to regulate a variety of cellular processes including apoptosis in such organisms. The signaling role of InsPs in unicellular organisms such as Dictyostelium discoideum (D. discoideum) is not well understood. We investigated whether InsPs also play any role in apoptosis in D. discoideum and whether InsPs-mediated apoptosis follows a mechanism similar to that present in higher multicellular eukaryotes. We measured known apoptotic markers in response to exogenously administered InsP6, the major InsPs in the cell. We found that InsP6 was able to cause cell death in D. discoideum cell culture in a dose- and time-dependent manner as determined by cytotoxicity assays. Fluorescence staining with acridine orange/ethidium bromide and flow cytometry results confirmed that the cell death in D. discoideum by InsP6 was due to apoptotic changes. Poly(ADP-ribose) expression, a known apoptotic marker used in D. discoideum, was also increased following InsP6 treatment suggesting a role for InsP6-mediated apoptosis in this organism. InsP6-mediated cell death was accompanied by production of reactive oxygen species and a decrease in mitochondrial membrane potential. Additionally, we studied the effects of InsP6 on the developmental life cycle of D. discoideum, the process likely affected by apoptosis. In conclusion, our studies provide evidence that InsP6-mediated cell death process is conserved in D. discoideum and plays an important signaling role in its developmental life cycle.
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Affiliation(s)
- Qudes Al-Anbaky
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA.,Department of Biology, University of Diyala, Baquba, Iraq
| | - Zeiyad Al-Karakooly
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA
| | - Richard Connor
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA
| | - Lisa Williams
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA
| | - Azure Yarbrough
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA
| | - John Bush
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA
| | - Nawab Ali
- Department of Biology, College of Arts, Letters and Sciences, University of Arkansas at Little Rock, 2801 S. University Avenue, Little Rock, AR, 72204, USA.
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Rajasekaran SS, Kim J, Gaboardi GC, Gromada J, Shears SB, Dos Santos KT, Nolasco EL, Ferreira SDS, Illies C, Köhler M, Gu C, Ryu SH, Martins JO, Darè E, Barker CJ, Berggren PO. Inositol hexakisphosphate kinase 1 is a metabolic sensor in pancreatic β-cells. Cell Signal 2018. [PMID: 29522819 PMCID: PMC5899964 DOI: 10.1016/j.cellsig.2018.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Diphosphoinositol pentakisphosphate (IP7) is critical for the exocytotic capacity of the pancreatic β-cell, but its regulation by the primary instigator of β-cell exocytosis, glucose, is unknown. The high Km for ATP of the IP7-generating enzymes, the inositol hexakisphosphate kinases (IP6K1 and 2) suggests that these enzymes might serve as metabolic sensors in insulin secreting β-cells and act as translators of disrupted metabolism in diabetes. We investigated this hypothesis and now show that glucose stimulation, which increases the ATP/ADP ratio, leads to an early rise in IP7 concentration in β-cells. RNAi mediated knock down of the IP6K1 isoform inhibits both glucose-mediated increase in IP7 and first phase insulin secretion, demonstrating that IP6K1 integrates glucose metabolism and insulin exocytosis. In diabetic mouse islets the deranged ATP/ADP levels under both basal and glucose-stimulated conditions are mirrored in both disrupted IP7 generation and insulin release. Thus the unique metabolic sensing properties of IP6K1 guarantees appropriate concentrations of IP7 and thereby both correct basal insulin secretion and intact first phase insulin release. In addition, our data suggest that a specific cell signaling defect, namely, inappropriate IP7 generation may be an essential convergence point integrating multiple metabolic defects into the commonly observed phenotype in diabetes. Glucose increases IP7 levels transiently through IP6K1 in pancreatic β-cells. IP6K1 decodes glucose-driven increases in ATP/ADP ratio into 1st phase insulin release. IP7 production and insulin release mirror perturbed metabolism in diabetic islets. IP6K1 acts as a β-cell metabolic sensor under normal and pathological conditions.
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Affiliation(s)
- Subu Surendran Rajasekaran
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Jaeyoon Kim
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Gian-Carlo Gaboardi
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | | | - Stephen B Shears
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239,111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Karen Tiago Dos Santos
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Eduardo Lima Nolasco
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sabrina de Souza Ferreira
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Christopher Illies
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Martin Köhler
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Chunfang Gu
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239,111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Sung Ho Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Joilson O Martins
- Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elisabetta Darè
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Christopher J Barker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea.
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55
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Brown NW, Marmelstein AM, Fiedler D. Chemical tools for interrogating inositol pyrophosphate structure and function. Chem Soc Rev 2018; 45:6311-6326. [PMID: 27462803 DOI: 10.1039/c6cs00193a] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The inositol pyrophosphates (PP-InsPs) are a unique group of intracellular messengers that represent some of the most highly phosphorylated molecules in nature. Genetic perturbation of the PP-InsP biosynthetic network indicates a central role for these metabolites in maintaining cellular energy homeostasis and in controlling signal transduction networks. However, despite their discovery over two decades ago, elucidating their physiologically relevant isomers, the biochemical pathways connecting these molecules to their associated phenotypes, and their modes of signal transduction has often been stymied by technical challenges. Many of the advances in understanding these molecules to date have been facilitated by the total synthesis of the various PP-InsP isomers and by the development of new methods that are capable of identifying their downstream signalling partners. Chemical tools have also been developed to distinguish between the proposed PP-InsP signal transduction mechanisms: protein binding, and a covalent modification of proteins termed protein pyrophosphorylation. In this article, we review these recent developments, discuss how they have helped to illuminate PP-InsP structure and function, and highlight opportunities for future discovery.
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Affiliation(s)
- Nathaniel W Brown
- Princeton University, Frick Chemistry Laboratory, Washington Road, Princeton, NJ 08544, USA and Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str 10, 13125 Berlin, Berlin, Germany.
| | - Alan M Marmelstein
- Princeton University, Frick Chemistry Laboratory, Washington Road, Princeton, NJ 08544, USA and Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str 10, 13125 Berlin, Berlin, Germany.
| | - Dorothea Fiedler
- Princeton University, Frick Chemistry Laboratory, Washington Road, Princeton, NJ 08544, USA and Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str 10, 13125 Berlin, Berlin, Germany.
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56
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Wei H, Landgraf D, Wang G, McCarthy MJ. Inositol polyphosphates contribute to cellular circadian rhythms: Implications for understanding lithium's molecular mechanism. Cell Signal 2018; 44:82-91. [PMID: 29331582 DOI: 10.1016/j.cellsig.2018.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 12/08/2017] [Accepted: 01/07/2018] [Indexed: 12/21/2022]
Abstract
Most living organisms maintain cell autonomous circadian clocks that synchronize critical biological functions with daily environmental cycles. In mammals, the circadian clock is regulated by inputs from signaling pathways including glycogen synthase kinase 3 (GSK3). The drug lithium has actions on GSK3, and also on inositol metabolism. While it is suspected that lithium's inhibition of GSK3 causes rhythm changes, it is not known if inositol polyphosphates can also affect the circadian clock. We examined whether the signaling molecule inositol hexaphosphate (IP6) has effects on circadian rhythms. Using a bioluminescent reporter (Per2::luc) to measure circadian rhythms, we determined that IP6 increased rhythm amplitude and shortened period in NIH3T3 cells. The IP6 effect on amplitude was attenuated by selective siRNA knockdown of GSK3B and pharmacological blockade of AKT kinase. However, unlike lithium, IP6 did not induce serine-9 phosphorylation of GSK3B. The synthesis of IP6 involves the enzymes inositol polyphosphate multikinase (IPMK) and inositol pentakisphosphate 2-kinase (IPPK). Knockdown of Ippk had effects opposite to those of IP6, decreasing rhythm amplitude and lengthening period. Ipmk knockdown had few effects on rhythm alone, but attenuated the effects of lithium on rhythms. However, lithium did not change the intracellular content of IP6 in NIH3T3 cells or neurons. Pharmacological inhibition of the IP6 kinases (IP6K) increased rhythm amplitude and shortened period, suggesting secondary effects of inositol pyrophosphates may underlie the period shortening effect, but not the amplitude increasing effect of IP6. Overall, we conclude that inositol phosphates, in particular IP6 have effects on circadian rhythms. Manipulations affecting IP6 and related inositol phosphates may offer a novel means through which circadian rhythms can be regulated.
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Affiliation(s)
- Heather Wei
- Research and Psychiatry Service, Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA 92161, United States; Department of Psychiatry and Center for Circadian Biology, University of California San Diego, 9500 Gilman Dr La Jolla, CA 92093, United States
| | - Dominic Landgraf
- Department of Psychiatry and Center for Circadian Biology, University of California San Diego, 9500 Gilman Dr La Jolla, CA 92093, United States
| | - George Wang
- Department of Psychiatry and Center for Circadian Biology, University of California San Diego, 9500 Gilman Dr La Jolla, CA 92093, United States
| | - Michael J McCarthy
- Research and Psychiatry Service, Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Dr, San Diego, CA 92161, United States; Department of Psychiatry and Center for Circadian Biology, University of California San Diego, 9500 Gilman Dr La Jolla, CA 92093, United States.
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57
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Park SJ, Lee S, Park SE, Kim S. Inositol pyrophosphates as multifaceted metabolites in the regulation of mammalian signaling networks. Anim Cells Syst (Seoul) 2017. [DOI: 10.1080/19768354.2017.1408684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Seung Ju Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seulgi Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seung Eun Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seyun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- KAIST Institute for the BioCentury, KAIST, Daejeon, Republic of Korea
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Wormald M, Liao G, Kimos M, Barrow J, Wei H. Development of a homogenous high-throughput assay for inositol hexakisphosphate kinase 1 activity. PLoS One 2017; 12:e0188852. [PMID: 29186181 PMCID: PMC5706701 DOI: 10.1371/journal.pone.0188852] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 11/14/2017] [Indexed: 11/18/2022] Open
Abstract
Inositol pyrophosphates have been implicated in a wide range of cellular processes. Inositol hexakisphosphate kinase 1 catalyzes the pyrophosphorylation of inositol hexakisphosphate into inositol 5-diphospho-1,2,3,4,6-pentakisphosphate which is important in numerous areas of cell physiology such as DNA repair and glucose homeostasis. Furthermore, inositol 5-diphospho-1,2,3,4,6-pentakisphosphate is implicated in the pathology of diabetes and other human diseases. As such there is a demonstrated need in the field for a robust chemical probe to better understand the role of inositol hexakisphosphate kinase 1 and inositol pyrophosphate in physiology and disease. To aid in this effort we developed a homogenous coupled bioluminescence assay for measuring inositol hexakisphosphate kinase 1 activity in a 384-well format (Z’ = 0.62±0.05). Using this assay we were able to confirm the activity of a known inositol hexakisphosphate kinase 1 inhibitor N2-(m-trifluorobenzyl), N6-(p-nitrobenzyl)purine. We also screened the Sigma library of pharmacologically active compounds at 10μM concentration and found 24 hits. Two of the most potent compounds were found to have an IC50 less than 5μM. The use of this high-throughput assay will accelerate the field towards the discovery of a potent inositol hexakisphosphate kinase 1 inhibitor.
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Affiliation(s)
- Michael Wormald
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, Maryland, United States of America
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
| | - Gangling Liao
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
| | - Martha Kimos
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
| | - James Barrow
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, Maryland, United States of America
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
| | - Huijun Wei
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
- * E-mail:
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59
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Rajasekaran SS, Illies C, Shears SB, Wang H, Ayala TS, Martins JO, Daré E, Berggren PO, Barker CJ. Protein kinase- and lipase inhibitors of inositide metabolism deplete IP 7 indirectly in pancreatic β-cells: Off-target effects on cellular bioenergetics and direct effects on IP6K activity. Cell Signal 2017; 42:127-133. [PMID: 29042286 PMCID: PMC5765549 DOI: 10.1016/j.cellsig.2017.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 12/22/2022]
Abstract
Inositol pyrophosphates have emerged as important regulators of many critical cellular processes from vesicle trafficking and cytoskeletal rearrangement to telomere length regulation and apoptosis. We have previously demonstrated that 5-di-phosphoinositol pentakisphosphate, IP7, is at a high level in pancreatic β-cells and is important for insulin exocytosis. To better understand IP7 regulation in β-cells, we used an insulin secreting cell line, HIT-T15, to screen a number of different pharmacological inhibitors of inositide metabolism for their impact on cellular IP7. Although the inhibitors have diverse targets, they all perturbed IP7 levels. This made us suspicious that indirect, off-target effects of the inhibitors could be involved. It is known that IP7 levels are decreased by metabolic poisons. The fact that the inositol hexakisphosphate kinases (IP6Ks) have a high Km for ATP makes IP7 synthesis potentially vulnerable to ATP depletion. Furthermore, many kinase inhibitors are targeted to the ATP binding site of kinases, but given the similarity of such sites, high specificity is difficult to achieve. Here, we show that IP7 concentrations in HIT-T15 cells were reduced by inhibitors of PI3K (wortmannin, LY294002), PI4K (Phenylarsine Oxide, PAO), PLC (U73122) and the insulin receptor (HNMPA). Each of these inhibitors also decreased the ATP/ADP ratio. Thus reagents that compromise energy metabolism reduce IP7 indirectly. Additionally, PAO, U73122 and LY294002 also directly inhibited the activity of purified IP6K. These data are of particular concern for those studying signal transduction in pancreatic β-cells, but also highlight the fact that employment of these inhibitors could have erroneously suggested the involvement of key signal transduction pathways in various cellular processes. Conversely, IP7’s role in cellular signal transduction is likely to have been underestimated. In pancreatic β-cells several inhibitors of signal transduction reduce IP7 levels. There is a positive correlation between IP7 reduction and decrease in ATP/ADP. Inhibitors deplete IP7 levels indirectly by decreasing ATP/ADP levels. Some purportedly specific cell-signaling inhibitors directly target IP6K activity. Caution is required in interpreting data obtained using inhibitors of inositide metabolism.
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Affiliation(s)
- Subu Surendran Rajasekaran
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Christopher Illies
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Stephen B Shears
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Huanchen Wang
- Signal Transduction Laboratory/Inositol Signaling Group, NIEHS, Building 101, Room F239, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Thais S Ayala
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden; Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Joilson O Martins
- Laboratory of Immunoendocrinology, Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Elisabetta Daré
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
| | - Christopher J Barker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
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60
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Boregowda SV, Ghoshal S, Booker CN, Krishnappa V, Chakraborty A, Phinney DG. IP6K1 Reduces Mesenchymal Stem/Stromal Cell Fitness and Potentiates High Fat Diet-Induced Skeletal Involution. Stem Cells 2017; 35:1973-1983. [PMID: 28577302 PMCID: PMC5533188 DOI: 10.1002/stem.2645] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/27/2017] [Accepted: 05/12/2017] [Indexed: 12/12/2022]
Abstract
Mesenchymal stem/stromal cells (MSCs) are the predominant source of bone and adipose tissue in adult bone marrow and play a critical role in skeletal homeostasis. Age‐induced changes in bone marrow favor adipogenesis over osteogenesis leading to skeletal involution and increased marrow adiposity so pathways that prevent MSC aging are potential therapeutic targets for treating age‐related bone diseases. Here, we show that inositol hexakisphosphate kinase 1 (Ip6k1) deletion in mice increases MSC yields from marrow and enhances cell growth and survival ex vivo. In response to the appropriate stimuli, Ip6k1−/− versus Ip6k1+/+ MSCs also exhibit enhanced osteogenesis and hematopoiesis‐supporting activity and reduced adipogenic differentiation. Mechanistic‐based studies revealed that Ip6k1−/− MSCs express higher MDM2 and lower p53 protein levels resulting in lower intrinsic mitochondrial reactive oxygen species (ROS) levels as compared to Ip6k1+/+ MSCs, but both populations upregulate mitochondrial ROS to similar extents in response to oxygen‐induced stress. Finally, we show that mice fed a high fat diet exhibit reduced trabecular bone volume, and that pharmacological inhibition of IP6K1 using a pan‐IP6K inhibitor largely reversed this phenotype while increasing MSC yields from bone marrow. Together, these findings reveal an important role for IP6K1 in regulating MSC fitness and differentiation fate. Unlike therapeutic interventions that target peroxisome proliferator‐activated receptor gamma and leptin receptor activity, which yield detrimental side effects including increased fracture risk and altered feeding behavior, respectively, inhibition of IP6K1 maintains insulin sensitivity and prevents obesity while preserving bone integrity. Therefore, IP6K1 inhibitors may represent more effective insulin sensitizers due to their bone sparing properties. Stem Cells2017;35:1973–1983
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Affiliation(s)
- Siddaraju V Boregowda
- Department of Molecular Medicine, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, USA
| | - Sarbani Ghoshal
- Department of Molecular Medicine, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, USA
| | - Cori N Booker
- Department of Molecular Medicine, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, USA
| | - Veena Krishnappa
- Department of Molecular Medicine, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, USA
| | - Anutosh Chakraborty
- Department of Molecular Medicine, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, USA
| | - Donald G Phinney
- Department of Molecular Medicine, The Scripps Research Institute-Scripps Florida, Jupiter, Florida, USA
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61
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Kim E, Ahn H, Kim MG, Lee H, Kim S. The Expanding Significance of Inositol Polyphosphate Multikinase as a Signaling Hub. Mol Cells 2017; 40:315-321. [PMID: 28554203 PMCID: PMC5463039 DOI: 10.14348/molcells.2017.0066] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/17/2017] [Indexed: 12/20/2022] Open
Abstract
The inositol polyphosphates are a group of multifunctional signaling metabolites whose synthesis is catalyzed by a family of inositol kinases that are evolutionarily conserved from yeast to humans. Inositol polyphosphate multikinase (IPMK) was first identified as a subunit of the arginine-responsive transcription complex in budding yeast. In addition to its role in the production of inositol tetrakis- and pentakisphosphates (IP4 and IP5), IPMK also exhibits phosphatidylinositol 3-kinase (PI3-kinase) activity. Through its PI3-kinase activity, IPMK activates Akt/PKB and its downstream signaling pathways. IPMK also regulates several protein targets non-catalytically via protein-protein interactions. These non-catalytic targets include cytosolic signaling factors and transcription factors in the nucleus. In this review, we highlight the many known functions of mammalian IPMK in controlling cellular signaling networks and discuss future challenges related to clarifying the unknown roles IPMK plays in physiology and disease.
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Affiliation(s)
- Eunha Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
| | - Hyoungjoon Ahn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
| | - Min Gyu Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
| | - Haein Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
| | - Seyun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
- KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141,
Korea
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Hatch AJ, Odom AR, York JD. Inositol phosphate multikinase dependent transcriptional control. Adv Biol Regul 2017; 64:9-19. [PMID: 28342784 PMCID: PMC6198329 DOI: 10.1016/j.jbior.2017.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 10/19/2022]
Abstract
Production of lipid-derived inositol phosphates including IP4 and IP5 is an evolutionarily conserved process essential for cellular adaptive responses that is dependent on both phospholipase C and the inositol phosphate multikinase Ipk2 (also known as Arg82 and IPMK). Studies of Ipk2, along with Arg82 prior to demonstrating its IP kinase activity, have provided an important link between control of gene expression and IP metabolism as both kinase dependent and independent functions are required for proper transcriptional complex function that enables cellular adaptation in response to extracellular queues such as nutrient availability. Here we define a promoter sequence cis-element, 5'-CCCTAAAAGG-3', that mediates both kinase-dependent and independent functions of Ipk2. Using a synthetic biological strategy, we show that proper gene expression in cells lacking Ipk2 may be restored through add-back of two components: IP4/IP5 production and overproduction of the MADS box DNA binding protein, Mcm1. Our results are consistent with a mechanism by which Ipk2 harbors a dual functionality that stabilizes transcription factor levels and enzymatically produces a small molecule code, which together coordinate control of biological processes and gene expression.
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Affiliation(s)
- Ace J Hatch
- Departments of Pharmacology and Cancer Biology and of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Audrey R Odom
- Departments of Pharmacology and Cancer Biology and of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - John D York
- Departments of Pharmacology and Cancer Biology and of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA; Department of Biochemistry, Vanderbilt University, 607 Light Hall, Nashville, TN 37232-0146, USA.
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Kim E, Beon J, Lee S, Park SJ, Ahn H, Kim MG, Park JE, Kim W, Yuk JM, Kang SJ, Lee SH, Jo EK, Seong RH, Kim S. Inositol polyphosphate multikinase promotes Toll-like receptor-induced inflammation by stabilizing TRAF6. SCIENCE ADVANCES 2017; 3:e1602296. [PMID: 28439546 PMCID: PMC5400429 DOI: 10.1126/sciadv.1602296] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 02/24/2017] [Indexed: 05/08/2023]
Abstract
Toll-like receptor (TLR) signaling is tightly controlled to protect hosts from microorganisms while simultaneously preventing uncontrolled immune responses. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a critical mediator of TLR signaling, but the precise mechanism of how TRAF6 protein stability is strictly controlled still remains obscure. We show that myeloid-specific deletion of inositol polyphosphate multikinase (IPMK), which has both inositol polyphosphate kinase activities and noncatalytic signaling functions, protects mice against polymicrobial sepsis and lipopolysaccharide-induced systemic inflammation. IPMK depletion in macrophages results in decreased levels of TRAF6 protein, thereby dampening TLR-induced signaling and proinflammatory cytokine production. Mechanistically, the regulatory role of IPMK is independent of its catalytic function, instead reflecting its direct binding to TRAF6. This interaction stabilizes TRAF6 by blocking its K48-linked ubiquitination and subsequent degradation by the proteasome. Thus, these findings identify IPMK as a key determinant of TRAF6 stability and elucidate the physiological function of IPMK in TLR-induced innate immunity.
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Affiliation(s)
- Eunha Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jiyoon Beon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seulgi Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seung Ju Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hyoungjoon Ahn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Min Gyu Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jeong Eun Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Wooseob Kim
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
| | - Jae-Min Yuk
- Department of Infection Biology, Chungnam National University School of Medicine, Daejeon 35015, Korea
| | - Suk-Jo Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seung-Hyo Lee
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 34141, Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 35015, Korea
| | - Rho Hyun Seong
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
- Corresponding author. (R.H.S.); (S.K.)
| | - Seyun Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- KAIST Institute for the BioCentury, KAIST, Daejeon 34141, Korea
- Corresponding author. (R.H.S.); (S.K.)
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64
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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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65
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Congenital Cataract in Gpr161vl/vl Mice Is Modified by Proximal Chromosome 15. PLoS One 2017; 12:e0170724. [PMID: 28135291 PMCID: PMC5279759 DOI: 10.1371/journal.pone.0170724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 01/10/2017] [Indexed: 11/24/2022] Open
Abstract
The morphology and severity of human congenital cataract varies even among individuals with the same mutation, suggesting that genetic background modifies phenotypic penetrance. The spontaneous mouse mutant, vacuolated lens (vl), arose on the C3H/HeSnJ background. The mutation disrupts secondary lens fiber development by E16.5, leading to full penetrance of congenital cataract. The vl locus was mapped to a frameshift deletion in the orphan G protein-coupled receptor, Gpr161, which is expressed in differentiating lens fiber cells. When Gpr161vl/vl C3H mice are crossed to MOLF/EiJ mice an unexpected rescue of cataract is observed, suggesting that MOLF modifiers affect cataract penetrance. Subsequent QTL analysis mapped three modifiers (Modvl3-5: Modifier of vl) and in this study we characterized Modvl4 (Chr15; LOD = 4.4). A Modvl4MOLF congenic was generated and is sufficient to rescue congenital cataract and the lens fiber defect at E16.5. Additional phenotypic analysis on three subcongenic lines narrowed down the interval from 55 to 15Mb. In total only 18 protein-coding genes and 2 micro-RNAs are in this region. Fifteen of the 20 genes show detectable expression in the E16.5 eye. Subsequent expression studies in Gpr161vl/vl and subcongenic E16.5 eyes, bioinformatics analysis of C3H/MOLF polymorphisms, and the biological relevancy of the genes in the interval identified three genes (Cdh6, Ank and Trio) that likely contribute to the rescue of the lens phenotype. These studies demonstrate that modification of the Gpr161vl/vl cataract phenotype is likely due to genetic variants in at least one of three closely linked candidate genes on proximal Chr15.
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66
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Yin MX, Catimel B, Gregory M, Condron M, Kapp E, Holmes AB, Burgess AW. Synthesis of an inositol hexakisphosphate (IP6) affinity probe to study the interactome from a colon cancer cell line. Integr Biol (Camb) 2016; 8:309-18. [PMID: 26840369 DOI: 10.1039/c5ib00264h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inositol hexakisphosphate (InsP6 or IP6) is an important signalling molecule in vesicular trafficking, neurotransmission, immune responses, regulation of protein kinases and phosphatases, activation of ion channels, antioxidant functions and anticancer activities. An IP6 probe was synthesised from myo-inositol via a derivatised analogue, which was immobilised through a terminal amino group onto Dynabeads. Systematic analysis of the IP6 interactome has been performed using the IP6 affinity probe using cytosolic extracts from the LIM1215 colonic carcinoma cell line. LC/MS/MS analysis identified 77 proteins or protein complexes that bind to IP6 specifically, including AP-2 complex proteins and β-arrestins as well as a number of novel potential IP6 interacting proteins. Bioinformatic enrichment analysis of the IP6 interactome reinforced the concept that IP6 regulates a number of biological processes including cell cycle and division, signal transduction, intracellular protein transport, vesicle-mediated transport and RNA splicing.
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Affiliation(s)
- Meng-Xin Yin
- School of Chemistry, Bio21 Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3052, Australia
| | - Bruno Catimel
- Ludwig Institute for Cancer Research, Melbourne-Austin Branch, Olivia Newton-John Cancer & Wellness Centre, Studley Road, Heidelberg, Victoria 3084, Australia
| | - Mark Gregory
- School of Chemistry, Bio21 Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3052, Australia
| | - Melanie Condron
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia. and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Eugene Kapp
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia. and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Andrew B Holmes
- School of Chemistry, Bio21 Institute, The University of Melbourne, 30 Flemington Road, Parkville, Victoria 3052, Australia
| | - Antony W Burgess
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia. and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia and Department of Surgery, RMH, University of Melbourne, Parkville, Victoria 3052, Australia
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67
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Zhu Q, Ghoshal S, Tyagi R, Chakraborty A. Global IP6K1 deletion enhances temperature modulated energy expenditure which reduces carbohydrate and fat induced weight gain. Mol Metab 2016; 6:73-85. [PMID: 28123939 PMCID: PMC5220553 DOI: 10.1016/j.molmet.2016.11.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/15/2016] [Accepted: 11/23/2016] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE IP6 kinases (IP6Ks) regulate cell metabolism and survival. Mice with global (IP6K1-KO) or adipocyte-specific (AdKO) deletion of IP6K1 are protected from diet induced obesity (DIO) at ambient (23 °C) temperature. AdKO mice are lean primarily due to increased AMPK mediated thermogenic energy expenditure (EE). Thus, at thermoneutral (30 °C) temperature, high fat diet (HFD)-fed AdKO mice expend energy and gain body weight, similar to control mice. IP6K1 is ubiquitously expressed; thus, it is critical to determine to what extent the lean phenotype of global IP6K1-KO mice depends on environmental temperature. Furthermore, it is not known whether IP6K1 regulates AMPK mediated EE in cells, which do not express UCP1. METHODS Q-NMR, GTT, food intake, EE, QRT-PCR, histology, mitochondrial oxygen consumption rate (OCR), fatty acid metabolism assays, and immunoblot studies were conducted in IP6K1-KO and WT mice or cells. RESULTS Global IP6K1 deletion mediated enhancement in EE is impaired albeit not abolished at 30 °C. As a result, IP6K1-KO mice are protected from DIO, insulin resistance, and fatty liver even at 30 °C. Like AdKO, IP6K1-KO mice display enhanced adipose tissue browning. However, unlike AdKO mice, thermoneutrality only partly abolishes browning in IP6K1-KO mice. Cold (5 °C) exposure enhances carbohydrate expenditure, whereas 23 °C and 30 °C promote fat oxidation in HFD-KO mice. Furthermore, IP6K1 deletion diminishes cellular fat accumulation via activation of the AMPK signaling pathway. CONCLUSIONS Global deletion of IP6K1 ameliorates obesity and insulin resistance irrespective of the environmental temperature conditions, which strengthens its validity as an anti-obesity target.
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Affiliation(s)
- Qingzhang Zhu
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Sarbani Ghoshal
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Richa Tyagi
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Anutosh Chakraborty
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL, 33458, USA.
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68
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Inositol polyphosphate multikinase (IPMK) in transcriptional regulation and nuclear inositide metabolism. Biochem Soc Trans 2016; 44:279-85. [PMID: 26862216 DOI: 10.1042/bst20150225] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Inositol polyphosphate multikinase (IPMK, ipk2, Arg(82), ArgRIII) is an inositide kinase with unusually flexible substrate specificity and the capacity to partake in many functional protein-protein interactions (PPIs). By merging these two activities, IPMK is able to execute gene regulatory functions that are very unique and only now beginning to be recognized. In this short review, we present a brief history of IPMK, describe the structural biology of the enzyme and highlight a few recent discoveries that have shed more light on the role IPMK plays in inositide metabolism, nuclear signalling and transcriptional regulation.
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69
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Inositol polyphosphates intersect with signaling and metabolic networks via two distinct mechanisms. Proc Natl Acad Sci U S A 2016; 113:E6757-E6765. [PMID: 27791083 DOI: 10.1073/pnas.1606853113] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Inositol-based signaling molecules are central eukaryotic messengers and include the highly phosphorylated, diffusible inositol polyphosphates (InsPs) and inositol pyrophosphates (PP-InsPs). Despite the essential cellular regulatory functions of InsPs and PP-InsPs (including telomere maintenance, phosphate sensing, cell migration, and insulin secretion), the majority of their protein targets remain unknown. Here, the development of InsP and PP-InsP affinity reagents is described to comprehensively annotate the interactome of these messenger molecules. By using the reagents as bait, >150 putative protein targets were discovered from a eukaryotic cell lysate (Saccharomyces cerevisiae). Gene Ontology analysis of the binding partners revealed a significant overrepresentation of proteins involved in nucleotide metabolism, glucose metabolism, ribosome biogenesis, and phosphorylation-based signal transduction pathways. Notably, we isolated and characterized additional substrates of protein pyrophosphorylation, a unique posttranslational modification mediated by the PP-InsPs. Our findings not only demonstrate that the PP-InsPs provide a central line of communication between signaling and metabolic networks, but also highlight the unusual ability of these molecules to access two distinct modes of action.
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70
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Zhu Q, Ghoshal S, Rodrigues A, Gao S, Asterian A, Kamenecka TM, Barrow JC, Chakraborty A. Adipocyte-specific deletion of Ip6k1 reduces diet-induced obesity by enhancing AMPK-mediated thermogenesis. J Clin Invest 2016; 126:4273-4288. [PMID: 27701146 DOI: 10.1172/jci85510] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 08/29/2016] [Indexed: 12/15/2022] Open
Abstract
Enhancing energy expenditure (EE) is an attractive strategy to combat obesity and diabetes. Global deletion of Ip6k1 protects mice from diet-induced obesity (DIO) and insulin resistance, but the tissue-specific mechanism by which IP6K1 regulates body weight is unknown. Here, we have demonstrated that IP6K1 regulates fat accumulation by modulating AMPK-mediated adipocyte energy metabolism. Cold exposure led to downregulation of Ip6k1 in murine inguinal and retroperitoneal white adipose tissue (IWAT and RWAT) depots. Adipocyte-specific deletion of Ip6k1 (AdKO) enhanced thermogenic EE, which protected mice from high-fat diet-induced weight gain at ambient temperature (23°C), but not at thermoneutral temperature (30°C). AdKO-induced increases in thermogenesis also protected mice from cold-induced decreases in body temperature. UCP1, PGC1α, and other markers of browning and thermogenesis were elevated in IWAT and RWAT of AdKO mice. Cold-induced activation of sympathetic signaling was unaltered, whereas AMPK was enhanced, in AdKO IWAT. Moreover, beige adipocytes from AdKO IWAT displayed enhanced browning, which was diminished by AMPK depletion. Furthermore, we determined that IP6 and IP6K1 differentially regulate upstream kinase-mediated AMPK stimulatory phosphorylation in vitro. Finally, treating mildly obese mice with the IP6K inhibitor TNP enhanced thermogenesis and inhibited progression of DIO. Thus, IP6K1 regulates energy metabolism via a mechanism that could potentially be targeted in obesity.
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71
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Systematic functional analysis of kinases in the fungal pathogen Cryptococcus neoformans. Nat Commun 2016; 7:12766. [PMID: 27677328 PMCID: PMC5052723 DOI: 10.1038/ncomms12766] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/01/2016] [Indexed: 12/15/2022] Open
Abstract
Cryptococcus neoformans is the leading cause of death by fungal meningoencephalitis; however, treatment options remain limited. Here we report the construction of 264 signature-tagged gene-deletion strains for 129 putative kinases, and examine their phenotypic traits under 30 distinct in vitro growth conditions and in two different hosts (insect larvae and mice). Clustering analysis of in vitro phenotypic traits indicates that several of these kinases have roles in known signalling pathways, and identifies hitherto uncharacterized signalling cascades. Virulence assays in the insect and mouse models provide evidence of pathogenicity-related roles for 63 kinases involved in the following biological categories: growth and cell cycle, nutrient metabolism, stress response and adaptation, cell signalling, cell polarity and morphology, vacuole trafficking, transfer RNA (tRNA) modification and other functions. Our study provides insights into the pathobiological signalling circuitry of C. neoformans and identifies potential anticryptococcal or antifungal drug targets. Cryptococcus neoformans is the leading cause of death by fungal meningoencephalitis. Here, the authors study the roles played by 129 putative kinases in the growth and virulence of C. neoformans, identifying potential targets for development of anticryptococcal drugs.
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72
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Li C, Lev S, Saiardi A, Desmarini D, Sorrell TC, Djordjevic JT. Inositol Polyphosphate Kinases, Fungal Virulence and Drug Discovery. J Fungi (Basel) 2016; 2:jof2030024. [PMID: 29376941 PMCID: PMC5753137 DOI: 10.3390/jof2030024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/23/2016] [Accepted: 08/30/2016] [Indexed: 12/31/2022] Open
Abstract
Opportunistic fungi are a major cause of morbidity and mortality world-wide, particularly in immunocompromised individuals. Developing new treatments to combat invasive fungal disease is challenging given that fungal and mammalian host cells are eukaryotic, with similar organization and physiology. Even therapies targeting unique fungal cell features have limitations and drug resistance is emerging. New approaches to the development of antifungal drugs are therefore needed urgently. Cryptococcus neoformans, the commonest cause of fungal meningitis worldwide, is an accepted model for studying fungal pathogenicity and driving drug discovery. We recently characterized a phospholipase C (Plc1)-dependent pathway in C. neoformans comprising of sequentially-acting inositol polyphosphate kinases (IPK), which are involved in synthesizing inositol polyphosphates (IP). We also showed that the pathway is essential for fungal cellular function and pathogenicity. The IP products of the pathway are structurally diverse, each consisting of an inositol ring, with phosphate (P) and pyrophosphate (PP) groups covalently attached at different positions. This review focuses on (1) the characterization of the Plc1/IPK pathway in C. neoformans; (2) the identification of PP-IP₅ (IP₇) as the most crucial IP species for fungal fitness and virulence in a mouse model of fungal infection; and (3) why IPK enzymes represent suitable candidates for drug development.
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Affiliation(s)
- Cecilia Li
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
| | - Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK.
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
| | - Tania C Sorrell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, NSW 2145, Australia.
- Westmead Hospital, Westmead, NSW 2145, Australia.
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia.
- Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Westmead, NSW 2145, Australia.
- Westmead Hospital, Westmead, NSW 2145, Australia.
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73
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Hager A, Wu M, Wang H, Brown NW, Shears SB, Veiga N, Fiedler D. Cellular Cations Control Conformational Switching of Inositol Pyrophosphate Analogues. Chemistry 2016; 22:12406-14. [PMID: 27460418 PMCID: PMC5076471 DOI: 10.1002/chem.201601754] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Indexed: 12/21/2022]
Abstract
The inositol pyrophosphate messengers (PP-InsPs) are emerging as an important class of cellular regulators. These molecules have been linked to numerous biological processes, including insulin secretion and cancer cell migration, but how they trigger such a wide range of cellular responses has remained unanswered in many cases. Here, we show that the PP-InsPs exhibit complex speciation behaviour and propose that a unique conformational switching mechanism could contribute to their multifunctional effects. We synthesised non-hydrolysable bisphosphonate analogues and crystallised the analogues in complex with mammalian PPIP5K2 kinase. Subsequently, the bisphosphonate analogues were used to investigate the protonation sequence, metal-coordination properties, and conformation in solution. Remarkably, the presence of potassium and magnesium ions enabled the analogues to adopt two different conformations near physiological pH. Understanding how the intrinsic chemical properties of the PP-InsPs can contribute to their complex signalling outputs will be essential to elucidate their regulatory functions.
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Affiliation(s)
- Anastasia Hager
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA
| | - Mingxuan Wu
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA
| | - Huanchen Wang
- Inositol Signaling Group, National Institutes of Health, Research Triangle Park, North Carolina, 27709, USA
| | - Nathaniel W Brown
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle Strasse 10, 13125, Berlin, Germany
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA
| | - Stephen B Shears
- Inositol Signaling Group, National Institutes of Health, Research Triangle Park, North Carolina, 27709, USA
| | - Nicolás Veiga
- Cátedra de Química Inorgánica, Departamento Estrella Campos, Facultad de Química, Universidad de la República, CC 1157, Montevideo, Uruguay.
| | - Dorothea Fiedler
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle Strasse 10, 13125, Berlin, Germany.
- Department of Chemistry, Princeton University, Washington Rd., Princeton, New Jersey, 08544, USA.
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Ghoshal S, Zhu Q, Asteian A, Lin H, Xu H, Ernst G, Barrow JC, Xu B, Cameron MD, Kamenecka TM, Chakraborty A. TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates diet induced obesity and insulin resistance via inhibition of the IP6K1 pathway. Mol Metab 2016; 5:903-917. [PMID: 27689003 PMCID: PMC5034689 DOI: 10.1016/j.molmet.2016.08.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/10/2016] [Accepted: 08/15/2016] [Indexed: 12/30/2022] Open
Abstract
Objective Obesity and type 2 diabetes (T2D) lead to various life-threatening diseases such as coronary heart disease, stroke, osteoarthritis, asthma, and neurodegeneration. Therefore, extensive research is ongoing to identify novel pathways that can be targeted in obesity/T2D. Deletion of the inositol pyrophosphate (5-IP7) biosynthetic enzyme, inositol hexakisphosphate kinase-1 (IP6K1), protects mice from high fat diet (HFD) induced obesity (DIO) and insulin resistance. Yet, whether this pathway is a valid pharmacologic target in obesity/T2D is not known. Here, we demonstrate that TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine], a pan-IP6K inhibitor, has strong anti-obesity and anti-diabetic effects in DIO mice. Methods Q-NMR, GTT, ITT, food intake, energy expenditure, QRT-PCR, ELISA, histology, and immunoblot studies were conducted in short (2.5-week)- and long (10-week)-term TNP treated DIO C57/BL6 WT and IP6K1-KO mice, under various diet and temperature conditions. Results TNP, when injected at the onset of HFD-feeding, decelerates initiation of DIO and insulin resistance. Moreover, TNP facilitates weight loss and restores metabolic parameters, when given to DIO mice. However, TNP does not reduce weight gain in HFD-fed IP6K1-KO mice. TNP specifically enhances insulin sensitivity in DIO mice via Akt activation. TNP decelerates weight gain primarily by enhancing thermogenic energy expenditure in the adipose tissue. Accordingly, TNP's effect on body weight is partly abolished whereas its impact on glucose homeostasis is preserved at thermoneutral temperature. Conclusion Pharmacologic inhibition of the inositol pyrophosphate pathway has strong therapeutic potential in obesity, T2D, and other metabolic diseases. Pharmacologic inhibition of IP6K by TNP, at the onset of high fat feeding, decelerates initiation of DIO and insulin resistance in mice. TNP, when treated to DIO mice, promotes weight loss and restores metabolic homeostasis. TNP does not reduce high fat diet induced weight gain in IP6K1-KO mice. TNP promotes insulin sensitivity by stimulating Akt activity, whereas it reduces body weight primarily by enhancing thermogenic energy expenditure. Long-term TNP treatment does not display deleterious side effects.
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Key Words
- 5-IP7, diphosphoinositol pentakisphosphate
- ALT, alanine aminotransferase
- AST, aspartate transaminase
- AUC, area under curve
- Akt
- BAT, brown adipose tissue
- CD, chow-diet
- CPT1a, carnitine palmitoyltransferase I
- Cidea, cell death activator-A
- DIO, diet-induced obesity
- Diabetes
- EE, energy expenditure
- EWAT, epididymal adipose tissue
- Energy expenditure
- GSK3, glycogen synthase kinase
- GTT, glucose tolerance test
- H&E, hematoxylin and eosin
- HFD, high-fat diet
- HPLC, high performance liquid chromatography
- IP6K
- IP6K, Inositol hexakisphosphate kinase
- IP6K1-KO, IP6K1 knockout
- ITT, insulin tolerance test
- IWAT, inguinal adipose tissue
- Inositol pyrophosphate
- Obesity
- PCR, polymerase chain reaction
- PGC1α, PPAR coactivator 1 alpha
- PKA, protein kinase A
- PPARγ, peroxisome proliferator-activated receptor gamma
- PRDM16, PR domain containing 16
- Pro-TNP, TNP treatment for protection against DIO
- Q-NMR, quantitative nuclear magnetic resonance
- QRT-PCR, quantitative reverse transcription polymerase chain reaction
- RER, Respiratory exchange ratio
- RWAT, retroperitoneal adipose tissue
- Rev-TNP, long-term TNP treatment for reversal of DIO
- RevT-TNP, Long-term TNP treatment for reversal of DIO at thermoneutral temperature
- S473, serine 473
- S9, serine 9
- SREV-TNP, short-term TNP treatment for reversal of DIO
- T2D, type-2 diabetes
- T308, threonine 308
- TNP, [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine]
- UCP-1/3, uncoupling protein 1/3
- VO2, volume of oxygen consumption
- WAT, white adipose tissue
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Affiliation(s)
- Sarbani Ghoshal
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Qingzhang Zhu
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Alice Asteian
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hua Lin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Haifei Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Glen Ernst
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, MD 21205, USA
| | - James C Barrow
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, MD 21205, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Michael D Cameron
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Theodore M Kamenecka
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Anutosh Chakraborty
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA.
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Abstract
Inositol pyrophosphates such as 5-diphosphoinositol pentakisphosphate (5-IP7) are highly energetic inositol metabolites containing phosphoanhydride bonds. Although inositol pyrophosphates are known to regulate various biological events, including growth, survival, and metabolism, the molecular sites of 5-IP7 action in vesicle trafficking have remained largely elusive. We report here that elevated 5-IP7 levels, caused by overexpression of inositol hexakisphosphate (IP6) kinase 1 (IP6K1), suppressed depolarization-induced neurotransmitter release from PC12 cells. Conversely, IP6K1 depletion decreased intracellular 5-IP7 concentrations, leading to increased neurotransmitter release. Consistently, knockdown of IP6K1 in cultured hippocampal neurons augmented action potential-driven synaptic vesicle exocytosis at synapses. Using a FRET-based in vitro vesicle fusion assay, we found that 5-IP7, but not 1-IP7, exhibited significantly higher inhibitory activity toward synaptic vesicle exocytosis than IP6 Synaptotagmin 1 (Syt1), a Ca(2+) sensor essential for synaptic membrane fusion, was identified as a molecular target of 5-IP7 Notably, 5-IP7 showed a 45-fold higher binding affinity for Syt1 compared with IP6 In addition, 5-IP7-dependent inhibition of synaptic vesicle fusion was abolished by increasing Ca(2+) levels. Thus, 5-IP7 appears to act through Syt1 binding to interfere with the fusogenic activity of Ca(2+) These findings reveal a role of 5-IP7 as a potent inhibitor of Syt1 in controlling the synaptic exocytotic pathway and expand our understanding of the signaling mechanisms of inositol pyrophosphates.
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76
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Inositol hexakisphosphate kinase-1 interacts with perilipin1 to modulate lipolysis. Int J Biochem Cell Biol 2016; 78:149-155. [PMID: 27373682 DOI: 10.1016/j.biocel.2016.06.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/20/2016] [Accepted: 06/28/2016] [Indexed: 12/21/2022]
Abstract
Lipolysis leads to the breakdown of stored triglycerides (TAG) to release free fatty acids (FFA) and glycerol which is utilized by energy expenditure pathways to generate energy. Therefore, a decrease in lipolysis augments fat accumulation in adipocytes which promotes weight gain. Conversely, if lipolysis is not complemented by energy expenditure, it leads to FFA induced insulin resistance and type-2 diabetes. Thus, lipolysis is under stringent physiological regulation, although the precise mechanism of the regulation is not known. Deletion of inositol hexakisphosphate kinase-1 (IP6K1), the major inositol pyrophosphate biosynthetic enzyme, protects mice from high fat diet (HFD) induced obesity and insulin resistance. IP6K1-KO mice are lean due to enhanced energy expenditure. Therefore, IP6K1 is a target in obesity and type-2 diabetes. However, the mechanism/s by which IP6K1 regulates adipose tissue lipid metabolism is yet to be understood. Here, we demonstrate that IP6K1-KO mice display enhanced basal lipolysis. IP6K1 modulates lipolysis via its interaction with the lipolytic regulator protein perilipin1 (PLIN1). Furthermore, phosphorylation of IP6K1 at a PKC/PKA motif modulates its interaction with PLIN1 and lipolysis. Thus, IP6K1 is a novel regulator of PLIN1 mediated lipolysis.
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77
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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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78
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Deletion of inositol hexakisphosphate kinase 1 (IP6K1) reduces cell migration and invasion, conferring protection from aerodigestive tract carcinoma in mice. Cell Signal 2016; 28:1124-36. [PMID: 27140681 PMCID: PMC4913618 DOI: 10.1016/j.cellsig.2016.04.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 04/20/2016] [Accepted: 04/28/2016] [Indexed: 11/21/2022]
Abstract
Inositol hexakisphosphate kinases (IP6Ks), a family of enzymes found in all eukaryotes, are responsible for the synthesis of 5-diphosphoinositol pentakisphosphate (5-IP7) from inositol hexakisphosphate (IP6). Three isoforms of IP6Ks are found in mammals, and gene deletions of each isoform lead to diverse, non-overlapping phenotypes in mice. Previous studies show a facilitatory role for IP6K2 in cell migration and invasion, properties that are essential for the early stages of tumorigenesis. However, IP6K2 also has an essential role in cancer cell apoptosis, and mice lacking this protein are more susceptible to the development of aerodigestive tract carcinoma upon treatment with the oral carcinogen 4-nitroquinoline-1-oxide (4NQO). Not much is known about the functions of the equally abundant and ubiquitously expressed IP6K1 isoform in cell migration, invasion and cancer progression. We conducted a gene expression analysis on mouse embryonic fibroblasts (MEFs) lacking IP6K1, revealing a role for this protein in cell receptor-extracellular matrix interactions that regulate actin cytoskeleton dynamics. Consequently, cells lacking IP6K1 manifest defects in adhesion-dependent signaling, evident by lower FAK and Paxillin activation, leading to reduced cell spreading and migration. Expression of active, but not inactive IP6K1 reverses migration defects in IP6K1 knockout MEFs, suggesting that 5-IP7 synthesis by IP6K1 promotes cell locomotion. Actin cytoskeleton remodeling and cell migration support the ability of cancer cells to achieve their complete oncogenic potential. Cancer cells with lower IP6K1 levels display reduced migration, invasion, and anchorage-independent growth. When fed an oral carcinogen, mice lacking IP6K1 show reduced progression from epithelial dysplasia to invasive carcinoma. Thus, our data reveal that like IP6K2, IP6K1 is also involved in early cytoskeleton remodeling events during cancer progression. However, unlike IP6K2, IP6K1 is essential for 4NQO-induced invasive carcinoma. Our study therefore uncovers similarities and differences in the roles of IP6K1 and IP6K2 in cancer progression, and we propose that an isoform-specific IP6K1 inhibitor may provide a novel route to suppress carcinogenesis. Gene-expression analysis of Ip6k1 knockout MEFs reveals down-regulation of cell surface-extracellular matrix signaling. Ip6k1 knockout MEFs show reduced adhesion-dependent signaling, cell spreading and migration. Cancer cells deficient in IP6K1 display reduced migration, invasion and anchorage independent growth. Mice lacking IP6K1 are resistant to progression from epithelial dysplasia to invasive carcinoma.
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79
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Yates LM, Fiedler D. A Stable Pyrophosphoserine Analog for Incorporation into Peptides and Proteins. ACS Chem Biol 2016; 11:1066-73. [PMID: 26760216 DOI: 10.1021/acschembio.5b00972] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein pyrophosphorylation is a covalent modification of proteins, mediated by the inositol pyrophosphate messengers. Although the inositol pyrophosphates have been linked to a range of cellular processes, the role of protein pyrophosphorylation remains minimally characterized in vivo. The inherent instability of the phosphoanhydride bond has hampered the development of useful bioanalytical techniques to interrogate this novel signaling mechanism. Here, we describe the preparation of a pyrophosphoserine analog containing a stable methylene-bisphosphonate group that is compatible with solid-phase peptide synthesis. The resulting peptides demonstrate enhanced stability in Eukaryotic cell lysates and mammalian plasma and display resistance toward chemical degradation, when compared to the corresponding pyrophosphopeptides. In addition, the peptides containing the stable pyrophosphoserine analog are highly compatible with common ligation methods, such as native chemical ligation, maleimide conjugation, and glutaraldehyde ligation. The bisphosphonate-containing peptides will, therefore, be well-suited for future pyrophosphoserine antibody generation and affinity capture of pyrophosphoprotein binding partners and provide a key entry point to study the regulatory role of protein pyrophosphorylation.
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Affiliation(s)
- Lisa M. Yates
- Department
of Chemistry, Princeton University, Washington Rd, Princeton, New Jersey 08544, United States
| | - Dorothea Fiedler
- Department
of Chemistry, Princeton University, Washington Rd, Princeton, New Jersey 08544, United States
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
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80
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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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81
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Bizzarri M, Dinicola S, Bevilacqua A, Cucina A. Broad Spectrum Anticancer Activity of Myo-Inositol and Inositol Hexakisphosphate. Int J Endocrinol 2016; 2016:5616807. [PMID: 27795708 PMCID: PMC5067332 DOI: 10.1155/2016/5616807] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/06/2016] [Indexed: 02/06/2023] Open
Abstract
Inositols (myo-inositol and inositol hexakisphosphate) exert a wide range of critical activities in both physiological and pathological settings. Deregulated inositol metabolism has been recorded in a number of diseases, including cancer, where inositol modulates different critical pathways. Inositols inhibit pRB phosphorylation, fostering the pRB/E2F complexes formation and blocking progression along the cell cycle. Inositols reduce PI3K levels, thus counteracting the activation of the PKC/RAS/ERK pathway downstream of PI3K activation. Upstream of that pathway, inositols disrupt the ligand interaction between FGF and its receptor as well as with the EGF-transduction processes involving IGF-II receptor and AP-1 complexes. Additionally, Akt activation is severely impaired upon inositol addition. Downregulation of both Akt and ERK leads consequently to NF-kB inhibition and reduced expression of inflammatory markers (COX-2 and PGE2). Remarkably, inositol-induced downregulation of presenilin-1 interferes with the epithelial-mesenchymal transition and reduces Wnt-activation, β-catenin translocation, Notch-1, N-cadherin, and SNAI1 release. Inositols interfere also with the cytoskeleton by upregulating Focal Adhesion Kinase and E-cadherin and decreasing Fascin and Cofilin, two main components of pseudopodia, leading hence to invasiveness impairment. This effect is reinforced by the inositol-induced inhibition on metalloproteinases and ROCK1/2 release. Overall, these effects enable inositols to remodel the cytoskeleton architecture.
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Affiliation(s)
- Mariano Bizzarri
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
- Systems Biology Group Lab, Sapienza University of Rome, Rome, Italy
- *Mariano Bizzarri:
| | - Simona Dinicola
- Department of Clinical and Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 336, 00161 Rome, Italy
- Department of Surgery “Pietro Valdoni”, Sapienza University of Rome, Via A. Scarpa 14, 00161 Rome, Italy
| | - Arturo Bevilacqua
- Department of Psychology, Section of Neuroscience, Sapienza University of Rome, Via dei Marsi 78, 00185 Rome, Italy
| | - Alessandra Cucina
- Department of Surgery “Pietro Valdoni”, Sapienza University of Rome, Via A. Scarpa 14, 00161 Rome, Italy
- Azienda Policlinico Umberto I, Viale del Policlinico 155, 00161 Rome, Italy
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82
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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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83
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Wang H, Nair VS, Holland AA, Capolicchio S, Jessen HJ, Johnson MK, Shears SB. Asp1 from Schizosaccharomyces pombe binds a [2Fe-2S](2+) cluster which inhibits inositol pyrophosphate 1-phosphatase activity. Biochemistry 2015; 54:6462-74. [PMID: 26422458 DOI: 10.1021/acs.biochem.5b00532] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Iron-sulfur (Fe-S) clusters are widely distributed protein cofactors that are vital to cellular biochemistry and the maintenance of bioenergetic homeostasis, but to our knowledge, they have never been identified in any phosphatase. Here, we describe an iron-sulfur cluster in Asp1, a dual-function kinase/phosphatase that regulates cell morphogenesis in Schizosaccharomyces pombe. Full-length Asp1, and its phosphatase domain (Asp1(371-920)), were each heterologously expressed in Escherichia coli. The phosphatase activity is exquisitely specific: it hydrolyzes the 1-diphosphate from just two members of the inositol pyrophosphate (PP-InsP) signaling family, namely, 1-InsP7 and 1,5-InsP8. We demonstrate that Asp1 does not hydrolyze either InsP6, 2-InsP7, 3-InsP7, 4-InsP7, 5-InsP7, 6-InsP7, or 3,5-InsP8. We also recorded 1-phosphatase activity in a human homologue of Asp1, hPPIP5K1, which was heterologously expressed in Drosophila S3 cells with a biotinylated N-terminal tag, and then isolated from cell lysates with avidin beads. Purified, recombinant Asp1(371-920) contained iron and acid-labile sulfide, but the stoichiometry (0.8 atoms of each per protein molecule) indicates incomplete iron-sulfur cluster assembly. We reconstituted the Fe-S cluster in vitro under anaerobic conditions, which increased the stoichiometry to approximately 2 atoms of iron and acid-labile sulfide per Asp1 molecule. The presence of a [2Fe-2S](2+) cluster in Asp1(371-920) was demonstrated by UV-visible absorption, resonance Raman spectroscopy, and electron paramagnetic resonance spectroscopy. We determined that this [2Fe-2S](2+) cluster is unlikely to participate in redox chemistry, since it rapidly degraded upon reduction by dithionite. Biochemical and mutagenic studies demonstrated that the [2Fe-2S](2+) cluster substantially inhibits the phosphatase activity of Asp1, thereby increasing its net kinase activity.
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Affiliation(s)
- Huanchen Wang
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health , 101 T. W. Alexander Drive, Research Triangle Park, North Carolina 27709, United States
| | - 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, North Carolina 27709, United States
| | - Ashley A Holland
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia , Athens, Georgia 30602, United States
| | - Samanta Capolicchio
- Department of Chemistry, University of Zurich (UZH) , Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Henning J Jessen
- Department of Chemistry, University of Zurich (UZH) , Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Michael K Johnson
- Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia , Athens, Georgia 30602, United States
| | - 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, North Carolina 27709, United States
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84
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Riley AM, Wang H, Shears SB, L. Potter BV. Synthetic tools for studying the chemical biology of InsP8. Chem Commun (Camb) 2015; 51:12605-8. [PMID: 26153667 PMCID: PMC4643724 DOI: 10.1039/c5cc05017k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 07/03/2015] [Indexed: 12/28/2022]
Abstract
To synthesise stabilised mimics of InsP8, the most phosphorylated inositol phosphate signalling molecule in Nature, we replaced its two diphosphate (PP) groups with either phosphonoacetate (PA) or methylenebisphosphonate (PCP) groups. Utility of the PA and PCP analogues was verified by structural and biochemical analyses of their interactions with enzymes of InsP8 metabolism.
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Affiliation(s)
- Andrew M. Riley
- Wolfson Laboratory of Medicinal Chemistry , Department of Pharmacy and Pharmacology , University of Bath , Claverton Down , Bath , BA2 7AY , UK
| | - Huanchen Wang
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Stephen B. Shears
- Inositol Signaling Group , Laboratory of Signal Transduction , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina , USA
| | - Barry V. L. Potter
- Wolfson Laboratory of Medicinal Chemistry , Department of Pharmacy and Pharmacology , University of Bath , Claverton Down , Bath , BA2 7AY , UK
- Department of Pharmacology , University of Oxford , Mansfield Road , Oxford , OX1 3QT , UK . ; Fax: +44-1865-271853 ; Tel: +44-1865-271945
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85
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Wilson MSC, Bulley SJ, Pisani F, Irvine RF, Saiardi A. A novel method for the purification of inositol phosphates from biological samples reveals that no phytate is present in human plasma or urine. Open Biol 2015; 5:150014. [PMID: 25808508 PMCID: PMC4389793 DOI: 10.1098/rsob.150014] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Inositol phosphates are a large and diverse family of signalling molecules. While
genetic studies have discovered important functions for them, the biochemistry
behind these roles is often not fully characterized. A key obstacle in inositol
phosphate research in mammalian cells has been the lack of straightforward
techniques for their purification and analysis. Here we describe the ability of
titanium dioxide (TiO2) beads to bind inositol phosphates. This
discovery allowed the development of a new purification protocol that, coupled
with gel analysis, permitted easy identification and quantification of
InsP6 (phytate), its pyrophosphate derivatives InsP7
and InsP8, and the nucleotides ATP and GTP from cell or tissue
extracts. Using this approach, InsP6, InsP7 and
InsP8 were visualized in Dictyostelium extracts
and a variety of mammalian cell lines and tissues, and the effects of metabolic
perturbation on these were explored. TiO2 bead purification also
enabled us to quantify InsP6 in human plasma and urine, which led to
two distinct but related observations. Firstly, there is an active
InsP6 phosphatase in human plasma, and secondly, InsP6
is undetectable in either fluid. These observations seriously question reports
that InsP6 is present in human biofluids and the advisability of
using InsP6 as a dietary supplement.
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Affiliation(s)
- Miranda S C Wilson
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Simon J Bulley
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK Department of Haematology, Cambridge University Hospitals NHS Trust, Hills Road, Cambridge CB2 0QQ, UK
| | - Francesca Pisani
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK Department of Biology, Ecology and Earth Science, University of Calabria, Rende, Italy
| | - Robin F Irvine
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
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86
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Huntington's disease: Neural dysfunction linked to inositol polyphosphate multikinase. Proc Natl Acad Sci U S A 2015. [PMID: 26195796 DOI: 10.1073/pnas.1511810112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disease caused by a glutamine repeat expansion in mutant huntingtin (mHtt). Despite the known genetic cause of HD, the pathophysiology of this disease remains to be elucidated. Inositol polyphosphate multikinase (IPMK) is an enzyme that displays soluble inositol phosphate kinase activity, lipid kinase activity, and various noncatalytic interactions. We report a severe loss of IPMK in the striatum of HD patients and in several cellular and animal models of the disease. This depletion reflects mHtt-induced impairment of COUP-TF-interacting protein 2 (Ctip2), a striatal-enriched transcription factor for IPMK, as well as alterations in IPMK protein stability. IPMK overexpression reverses the metabolic activity deficit in a cell model of HD. IPMK depletion appears to mediate neural dysfunction, because intrastriatal delivery of IPMK abates the progression of motor abnormalities and rescues striatal pathology in transgenic murine models of HD.
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87
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Schimpf KJ, Meek CC, Leff RD, Phelps DL, Schmitz DJ, Cordle CT. Quantification of myo-inositol, 1,5-anhydro- D-sorbitol, and D-chiro-inositol using high-performance liquid chromatography with electrochemical detection in very small volume clinical samples. Biomed Chromatogr 2015; 29:1629-36. [PMID: 26010453 DOI: 10.1002/bmc.3470] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 02/05/2015] [Accepted: 03/02/2015] [Indexed: 11/11/2022]
Abstract
Inositol is a six-carbon sugar alcohol and is one of nine biologically significant isomers of hexahydroxycyclohexane. Myo-inositol is the primary biologically active form and is present in higher concentrations in the fetus and newborn than in adults. It is currently being examined for the prevention of retinopathy of prematurity in newborn preterm infants. A robust method for quantifying myo-inositol (MI), D-chiro-inositol (DCI) and 1,5-anhydro- D-sorbitol (ADS) in very small-volume (25 μL) urine, blood serum and/or plasma samples was developed. Using a multiple-column, multiple mobile phase liquid chromatographic system with electrochemical detection, the method was validated with respect to (a) selectivity, (b) accuracy/recovery, (c) precision/reproducibility, (d) sensitivity, (e) stability and (f) ruggedness. The standard curve was linear and ranged from 0.5 to 30 mg/L for each of the three analytes. Above-mentioned performance measures were within acceptable limits described in the Food and Drug Administration's Guidance for Industry: Bioanalytical Method Validation. The method was validated using blood serum and plasma collected using four common anticoagulants, and also by quantifying the accuracy and sensitivity of MI measured in simulated urine samples recovered from preterm infant diaper systems. The method performs satisfactorily measuring the three most common inositol isomers on 25 μL clinical samples of serum, plasma, milk, and/or urine. Similar performance is seen testing larger volume samples of infant formulas and infant formula ingredients. MI, ADS and DCI may be accurately tested in urine samples collected from five different preterm infant diapers if the urine volume is greater than 2-5 mL.
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Affiliation(s)
- Karen J Schimpf
- Abbott Nutrition, 3300 Stelzer Road, Columbus, OH, 34219, USA
| | - Claudia C Meek
- School of Pharmacy, Texas Tech University Health Sciences Center, 5920 Forest Park Road - Suite 400, Dallas, TX, 75235, USA
| | - Richard D Leff
- School of Pharmacy, Texas Tech University Health Sciences Center, 5920 Forest Park Road - Suite 400, Dallas, TX, 75235, USA
| | - Dale L Phelps
- University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Pediatrics, Box 651, Rochester, NY, 14642, USA
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88
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Inositol pyrophosphates regulate RNA polymerase I-mediated rRNA transcription in Saccharomyces cerevisiae. Biochem J 2015; 466:105-14. [PMID: 25423617 PMCID: PMC4325516 DOI: 10.1042/bj20140798] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosome biogenesis is an essential cellular process regulated by the metabolic state of a cell. We examined whether inositol pyrophosphates, energy-rich derivatives of inositol that act as metabolic messengers, play a role in ribosome synthesis in the budding yeast, Saccharomyces cerevisiae. Yeast strains lacking the inositol hexakisphosphate (IP6) kinase Kcs1, which is required for the synthesis of inositol pyrophosphates, display increased sensitivity to translation inhibitors and decreased protein synthesis. These phenotypes are reversed on expression of enzymatically active Kcs1, but not on expression of the inactive form. The kcs1Δ yeast cells exhibit reduced levels of ribosome subunits, suggesting that they are defective in ribosome biogenesis. The rate of rRNA synthesis, the first step of ribosome biogenesis, is decreased in kcs1Δ yeast strains, suggesting that RNA polymerase I (Pol I) activity may be reduced in these cells. We determined that the Pol I subunits, A190, A43 and A34.5, can accept a β-phosphate moiety from inositol pyrophosphates to undergo serine pyrophosphorylation. Although there is impaired rRNA synthesis in kcs1Δ yeast cells, we did not find any defect in recruitment of Pol I on rDNA, but observed that the rate of transcription elongation was compromised. Taken together, our findings highlight inositol pyrophosphates as novel regulators of rRNA transcription. Inositol pyrophosphates are phosphate-rich metabolic messengers that regulate many cellular processes. We observed that RNA polymerase I is pyrophosphorylated by inositol pyrophosphates, and its transcription elongation activity was reduced in budding yeast strains devoid of inositol pyrophosphates.
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89
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Laha D, Johnen P, Azevedo C, Dynowski M, Weiß M, Capolicchio S, Mao H, Iven T, Steenbergen M, Freyer M, Gaugler P, de Campos MKF, Zheng N, Feussner I, Jessen HJ, Van Wees SCM, Saiardi A, Schaaf G. VIH2 Regulates the Synthesis of Inositol Pyrophosphate InsP8 and Jasmonate-Dependent Defenses in Arabidopsis. THE PLANT CELL 2015; 27:1082-97. [PMID: 25901085 PMCID: PMC4558690 DOI: 10.1105/tpc.114.135160] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/13/2015] [Accepted: 04/03/2015] [Indexed: 05/20/2023]
Abstract
Diphosphorylated inositol polyphosphates, also referred to as inositol pyrophosphates, are important signaling molecules that regulate critical cellular activities in many eukaryotic organisms, such as membrane trafficking, telomere maintenance, ribosome biogenesis, and apoptosis. In mammals and fungi, two distinct classes of inositol phosphate kinases mediate biosynthesis of inositol pyrophosphates: Kcs1/IP6K- and Vip1/PPIP5K-like proteins. Here, we report that PPIP5K homologs are widely distributed in plants and that Arabidopsis thaliana VIH1 and VIH2 are functional PPIP5K enzymes. We show a specific induction of inositol pyrophosphate InsP8 by jasmonate and demonstrate that steady state and jasmonate-induced pools of InsP8 in Arabidopsis seedlings depend on VIH2. We identify a role of VIH2 in regulating jasmonate perception and plant defenses against herbivorous insects and necrotrophic fungi. In silico docking experiments and radioligand binding-based reconstitution assays show high-affinity binding of inositol pyrophosphates to the F-box protein COI1-JAZ jasmonate coreceptor complex and suggest that coincidence detection of jasmonate and InsP8 by COI1-JAZ is a critical component in jasmonate-regulated defenses.
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Affiliation(s)
- Debabrata Laha
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | - Philipp Johnen
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | - Cristina Azevedo
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom
| | - Marek Dynowski
- Zentrum für Datenverarbeitung, University of Tübingen, 72074 Tübingen, Germany
| | - Michael Weiß
- Department of Biology, University of Tübingen, 72076 Tübingen, Germany
| | | | - Haibin Mao
- Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195
| | - Tim Iven
- Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Merel Steenbergen
- Plant-Microbe Interactions, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Marc Freyer
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | - Philipp Gaugler
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
| | | | - Ning Zheng
- Department of Pharmacology, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195
| | - Ivo Feussner
- Department of Plant Biochemistry, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Henning J Jessen
- Department of Chemistry, University of Zürich, 8057 Zurich, Switzerland
| | - Saskia C M Van Wees
- Plant-Microbe Interactions, Department of Biology, Utrecht University, 3508 TB Utrecht, The Netherlands
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom
| | - Gabriel Schaaf
- Center for Plant Molecular Biology, University of Tübingen, 72076 Tübingen, Germany
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90
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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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91
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Conway JH, Fiedler D. An Affinity Reagent for the Recognition of Pyrophosphorylated Peptides. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201411232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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92
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Conway JH, Fiedler D. An affinity reagent for the recognition of pyrophosphorylated peptides. Angew Chem Int Ed Engl 2015; 54:3941-5. [PMID: 25651128 DOI: 10.1002/anie.201411232] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Indexed: 11/05/2022]
Abstract
A resin-bound dinuclear zinc(II) complex for the selective capture of pyrophosphopeptides is reported. The metal complex binds diphosphate esters over other anionic groups, such as monophosphate esters, sulfate esters, and carboxylic acids, with high specificity. Immobilization of the compound provided a reagent capable of binding and retaining nanomolar quantities of pyrophosphopeptide in the presence of cell lysate. The high affinity and specificity of the reagent makes it an attractive tool for the study of in vivo pyrophosphorylation.
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Affiliation(s)
- John H Conway
- Department of Chemistry, Princeton University, Washington Rd, Princeton, NJ 08544 (USA)
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93
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Yates LM, Fiedler D. Establishing the Stability and Reversibility of Protein Pyrophosphorylation with Synthetic Peptides. Chembiochem 2015; 16:415-23. [DOI: 10.1002/cbic.201402589] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Indexed: 12/24/2022]
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94
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Inositol pyrophosphates promote tumor growth and metastasis by antagonizing liver kinase B1. Proc Natl Acad Sci U S A 2015; 112:1773-8. [PMID: 25617365 DOI: 10.1073/pnas.1424642112] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The inositol pyrophosphates, molecular messengers containing an energetic pyrophosphate bond, impact a wide range of biologic processes. They are generated primarily by a family of three inositol hexakisphosphate kinases (IP6Ks), the principal product of which is diphosphoinositol pentakisphosphate (IP7). We report that IP6K2, via IP7 synthesis, is a major mediator of cancer cell migration and tumor metastasis in cell culture and in intact mice. IP6K2 acts by enhancing cell-matrix adhesion and decreasing cell-cell adhesion. This action is mediated by IP7-elicited nuclear sequestration and inactivation of the tumor suppressor liver kinase B1 (LKB1). Accordingly, inhibitors of IP6K2 offer promise in cancer therapy.
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95
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Rao F, Xu J, Khan AB, Gadalla MM, Cha JY, Xu R, Tyagi R, Dang Y, Chakraborty A, Snyder SH. Inositol hexakisphosphate kinase-1 mediates assembly/disassembly of the CRL4-signalosome complex to regulate DNA repair and cell death. Proc Natl Acad Sci U S A 2014; 111:16005-10. [PMID: 25349427 PMCID: PMC4234592 DOI: 10.1073/pnas.1417900111] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inositol polyphosphates containing an energetic pyrophosphate bond are formed primarily by a family of three inositol hexakisphosphate (IP6) kinases (IP6K1-3). The Cullin-RING ubiquitin ligases (CRLs) regulate diverse biological processes through substrate ubiquitylation. CRL4, comprising the scaffold Cullin 4A/B, the E2-interacting Roc1/2, and the adaptor protein damage-specific DNA-binding protein 1, is activated by DNA damage. Basal CRL4 activity is inhibited by binding to the COP9 signalosome (CSN). UV radiation and other stressors dissociate the complex, leading to E3 ligase activation, but signaling events that trigger signalosome dissociation from CRL4 have been unclear. In the present study, we show that, under basal conditions, IP6K1 forms a ternary complex with CSN and CRL4 in which IP6K1 and CRL4 are inactive. UV dissociates IP6K1 to generate IP7, which then dissociates CSN-CRL4 to activate CRL4. Thus, IP6K1 is a novel CRL4 subunit that transduces UV signals to mediate disassembly of the CRL4-CSN complex, thereby regulating nucleotide excision repair and cell death.
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Affiliation(s)
- Feng Rao
- The Solomon H. Snyder Department of Neuroscience
| | - Jing Xu
- The Solomon H. Snyder Department of Neuroscience
| | - A Basit Khan
- The Solomon H. Snyder Department of Neuroscience
| | - Moataz M Gadalla
- The Solomon H. Snyder Department of Neuroscience, Department of Pharmacology and Molecular Sciences, and
| | | | - Risheng Xu
- The Solomon H. Snyder Department of Neuroscience, Department of Pharmacology and Molecular Sciences, and
| | - Richa Tyagi
- The Solomon H. Snyder Department of Neuroscience
| | - Yongjun Dang
- Department of Pharmacology and Molecular Sciences, and
| | | | - Solomon H Snyder
- The Solomon H. Snyder Department of Neuroscience, Department of Pharmacology and Molecular Sciences, and Department of Psychiatry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205
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96
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Abstract
The polymer inorganic polyP (polyphosphate) and inositol phosphates, such as IP6 (inositol hexakisphosphate; also known as phytic acid), share many biophysical features. These similarities must be attributed to the phosphate groups present in these molecules. Given the ability of polyP to modify the excitation-emission spectra of DAPI we decided to investigate whether inositol phosphates possess the same property. We discovered that DAPI-IP6 complexes emit at approximately 550 nm when excited with light of wavelength 410-420 nm. IP5 (inositol pentakisphosphate) is also able to induce a similar shift in DAPI fluorescence. Conversely, IP3 (inositol trisphosphate) and IP4 (inositol tetrakisphosphate) are unable to shift DAPI fluorescence. We have employed this newly discovered feature of DAPI to study the enzymatic activity of the inositol polyphosphate multikinase and to monitor phytase phosphatase reactions. Finally, we used DAPI-IP6 fluorescence to determine the amount of IP6 in plant seeds. Using an IP6 standard curve this straight-forward analysis revealed that among the samples tested, borlotti beans possess the highest level of IP6 (9.4 mg/g of dry mass), whereas the Indian urad bean the lowest (3.2 mg/g of dry mass). The newly identified fluorescence properties of the DAPI-IP5 and DAPI-IP6 complexes allow the levels and enzymatic conversion of these two important messengers to be rapidly and reliably monitored.
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97
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Braun KA, Vaga S, Dombek KM, Fang F, Palmisano S, Aebersold R, Young ET. Phosphoproteomic analysis identifies proteins involved in transcription-coupled mRNA decay as targets of Snf1 signaling. Sci Signal 2014; 7:ra64. [PMID: 25005228 DOI: 10.1126/scisignal.2005000] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stresses, such as glucose depletion, activate Snf1, the Saccharomyces cerevisiae ortholog of adenosine monophosphate-activated protein kinase (AMPK), enabling adaptive cellular responses. In addition to affecting transcription, Snf1 may also promote mRNA stability in a gene-specific manner. To understand Snf1-mediated signaling, we used quantitative mass spectrometry to identify proteins that were phosphorylated in a Snf1-dependent manner. We identified 210 Snf1-dependent phosphopeptides in 145 proteins. Thirteen of these proteins are involved in mRNA metabolism. Of these, we found that Ccr4 (the major cytoplasmic deadenylase), Dhh1 (an RNA helicase), and Xrn1 (an exoribonuclease) were required for the glucose-induced decay of Snf1-dependent mRNAs that were activated by glucose depletion. Unexpectedly, deletion of XRN1 reduced the accumulation of Snf1-dependent transcripts that were synthesized during glucose depletion. Deletion of SNF1 rescued the synthetic lethality of simultaneous deletion of XRN1 and REG1, which encodes a regulatory subunit of a phosphatase that inhibits Snf1. Mutation of three Snf1-dependent phosphorylation sites in Xrn1 reduced glucose-induced mRNA decay. Thus, Xrn1 is required for Snf1-dependent mRNA homeostasis in response to nutrient availability.
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Affiliation(s)
- Katherine A Braun
- Department of Biochemistry, University of Washington, 1705 Northeast Pacific Street, Seattle, WA 98195-7350, USA
| | - Stefania Vaga
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, CH-8057 Zurich, Switzerland
| | - Kenneth M Dombek
- Department of Biochemistry, University of Washington, 1705 Northeast Pacific Street, Seattle, WA 98195-7350, USA
| | - Fang Fang
- Department of Biochemistry, University of Washington, 1705 Northeast Pacific Street, Seattle, WA 98195-7350, USA
| | - Salvator Palmisano
- Department of Biochemistry, University of Washington, 1705 Northeast Pacific Street, Seattle, WA 98195-7350, USA
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, CH-8057 Zurich, Switzerland. Faculty of Science, University of Zurich, CH-8057 Zurich, Switzerland
| | - Elton T Young
- Department of Biochemistry, University of Washington, 1705 Northeast Pacific Street, Seattle, WA 98195-7350, USA.
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98
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Wu M, Chong LS, Capolicchio S, Jessen HJ, Resnick AC, Fiedler D. Elucidating diphosphoinositol polyphosphate function with nonhydrolyzable analogues. Angew Chem Int Ed Engl 2014; 53:7192-7. [PMID: 24888434 DOI: 10.1002/anie.201402905] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/25/2014] [Indexed: 11/11/2022]
Abstract
The diphosphoinositol polyphosphates (PP-IPs) represent a novel class of high-energy phosphate-containing messengers which control a wide variety of cellular processes. It is thought that PP-IPs exert their pleiotropic effects as allosteric regulators and through pyrophosphorylation of protein substrates. However, most details of PP-IP signaling have remained elusive because of a paucity of suitable tools. We describe the synthesis of PP-IP bisphosphonate analogues (PCP-IPs), which are resistant to chemical and biochemical degradation. While the two regioisomers 1PCP-IP5 and 5PCP-IP5 inhibited Akt phosphorylation with similar potencies, 1PCP-IP5 was much more effective at inhibiting its cognate phosphatase hDIPP1. Furthermore, the PCP analogues inhibit protein pyrophosphorylation because of their inability to transfer the β-phosphoryl group, and thus enable the distinction between PP-IP signaling mechanisms. As such, the PCP analogues will find widespread applications for the structural and biochemical characterization of PP-IP signaling properties.
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Affiliation(s)
- Mingxuan Wu
- Department of Chemistry, Princeton University, Washington Rd, Princeton, NJ 08544 (USA)
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99
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Wu M, Chong LS, Capolicchio S, Jessen HJ, Resnick AC, Fiedler D. Elucidating Diphosphoinositol Polyphosphate Function with Nonhydrolyzable Analogues. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402905] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mingxuan Wu
- Department of Chemistry, Princeton University, Washington Rd, Princeton, NJ 08544 (USA)
| | - Lucy S. Chong
- Colket Translational Research Bldg, The Children's Hospital of Philadelphia, 3501 Civic Center Blvd, Philadelphia, PA 19104 (USA)
| | - Samanta Capolicchio
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland)
| | - Henning J. Jessen
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland)
| | - Adam C. Resnick
- Colket Translational Research Bldg, The Children's Hospital of Philadelphia, 3501 Civic Center Blvd, Philadelphia, PA 19104 (USA)
| | - Dorothea Fiedler
- Department of Chemistry, Princeton University, Washington Rd, Princeton, NJ 08544 (USA)
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100
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Adikesavan AK, Karmakar S, Pardo P, Wang L, Liu S, Li W, Smith CL. Activation of p53 transcriptional activity by SMRT: a histone deacetylase 3-independent function of a transcriptional corepressor. Mol Cell Biol 2014; 34:1246-61. [PMID: 24449765 PMCID: PMC3993559 DOI: 10.1128/mcb.01216-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The silencing mediator of retinoic acid and thyroid hormone receptors (SMRT) is an established histone deacetylase 3 (HDAC3)-dependent transcriptional corepressor. Microarray analyses of MCF-7 cells transfected with control or SMRT small interfering RNA revealed SMRT regulation of genes involved in DNA damage responses, and the levels of the DNA damage marker γH2AX as well as poly(ADP-ribose) polymerase cleavage were elevated in SMRT-depleted cells treated with doxorubicin. A number of these genes are established p53 targets. SMRT knockdown decreased the activity of two p53-dependent reporter genes as well as the expression of p53 target genes, such as CDKN1A (which encodes p21). SMRT bound directly to p53 and was recruited to p53 binding sites within the p21 promoter. Depletion of GPS2 and TBL1, components of the SMRT corepressor complex, but not histone deacetylase 3 (HDAC3) decreased p21-luciferase activity. p53 bound to the SMRT deacetylase activation domain (DAD), which mediates HDAC3 binding and activation, and HDAC3 could attenuate p53 binding to the DAD region of SMRT. Moreover, an HDAC3 binding-deficient SMRT DAD mutant coactivated p53 transcriptional activity. Collectively, these data highlight a biological role for SMRT in mediating DNA damage responses and suggest a model where p53 binding to the DAD limits HDAC3 interaction with this coregulator, thereby facilitating SMRT coactivation of p53-dependent gene expression.
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Affiliation(s)
| | - Sudipan Karmakar
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Patricia Pardo
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Liguo Wang
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - Shuang Liu
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Wei Li
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas, USA
| | - Carolyn L. Smith
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, USA
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