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Pei W, Jain A, Zhao G, Feng B, Xu D, Wang X. Knockdown of OsSAE1a affects the growth and development and phosphate homeostasis in rice. JOURNAL OF PLANT PHYSIOLOGY 2020; 255:153275. [PMID: 33161338 DOI: 10.1016/j.jplph.2020.153275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/31/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
SUMOylation is a post-translational modification process that comprises a tandem enzymatic cascade, i.e., maturation, activation, conjugation, and ligation of a small ubiquitin-like modifier, which triggers the modulated activities and transport of the cellular proteins to other areas of the cell. In Oryza sativa (rice), OsSIZ1/2 encoding E3 SUMO ligase exerts regulatory influences on Pi homeostasis and developmental responses. However, the role of OsSAE1a, SUMO E1 activating enzyme, in regulating phosphate (Pi) utilization and/or growth and development is not known in rice and was thus investigated in this study. The qRT-PCR assay revealed a constitutive and variable spatiotemporal expression pattern of OsSAE1a in the vegetative and reproductive tissues and was comparable in the root and shoot grown under different Pi regimes. RNAi-mediated suppression of OsSAE1a exerted variable effects on the concentrations of Pi and total P in different tissues, uptake and distribution of 32Pi, and relative expression levels of several genes that play pivotal roles in the maintenance of Pi homeostasis. The effects of the mutation in OsSAE1a were also evident in the vegetative and reproductive traits of rice during growth in a hydroponic system and pot soil, respectively. Overall, these results suggest a broad-spectrum role of OsSAE1a in the maintenance of Pi homeostasis and regulating growth and development.
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Affiliation(s)
- Wenxia Pei
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China; College of Resource and Environment, Anhui Science and Technology University, Chuzhou, 233100, China
| | - Ajay Jain
- Amity Institute of Biotechnology, Amity University Rajasthan, Jaipur, India
| | - Gengmao Zhao
- Jiangsu Provincial Key Lab of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Bing Feng
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Dayong Xu
- Agricultural Bureau of Lanshan District, Linyi, 276000, China
| | - Xiaowen Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China; Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
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52
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Shuman S. Transcriptional interference at tandem lncRNA and protein-coding genes: an emerging theme in regulation of cellular nutrient homeostasis. Nucleic Acids Res 2020; 48:8243-8254. [PMID: 32720681 PMCID: PMC7470944 DOI: 10.1093/nar/gkaa630] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/10/2020] [Accepted: 07/26/2020] [Indexed: 12/29/2022] Open
Abstract
Tandem transcription interference occurs when the act of transcription from an upstream promoter suppresses utilization of a co-oriented downstream promoter. Because eukaryal genomes are liberally interspersed with transcription units specifying long non-coding (lnc) RNAs, there are many opportunities for lncRNA synthesis to negatively affect a neighboring protein-coding gene. Here, I review two eukaryal systems in which lncRNA interference with mRNA expression underlies a regulated biological response to nutrient availability. Budding yeast SER3 is repressed under serine-replete conditions by transcription of an upstream SRG1 lncRNA that traverses the SER3 promoter and elicits occlusive nucleosome rearrangements. SER3 is de-repressed by serine withdrawal, which leads to shut-off of SRG1 synthesis. The fission yeast phosphate homeostasis (PHO) regulon comprises three phosphate acquisition genes – pho1, pho84, and tgp1 – that are repressed under phosphate-replete conditions by 5′ flanking lncRNAs prt, prt2, and nc-tgp1, respectively. lncRNA transcription across the PHO mRNA promoters displaces activating transcription factor Pho7. PHO mRNAs are transcribed during phosphate starvation when lncRNA synthesis abates. The PHO regulon is de-repressed in phosphate-replete cells by genetic manipulations that favor ‘precocious’ lncRNA 3′-processing/termination upstream of the mRNA promoters. PHO lncRNA termination is governed by the Pol2 CTD code and is subject to metabolite control by inositol pyrophosphates.
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Affiliation(s)
- Stewart Shuman
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
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53
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Abstract
In the human-pathogenic fungus Cryptococcus neoformans, the inositol polyphosphate signaling pathway is critical for virulence. We recently demonstrated the key role of the inositol pyrophosphate IP7 (isomer 5-PP-IP5) in driving fungal virulence; however, the mechanism of action remains elusive. Using genetic and biochemical approaches, and mouse infection models, we show that IP7 synthesized by Kcs1 regulates fungal virulence by binding to a conserved lysine surface cluster in the SPX domain of Pho81. Pho81 is the cyclin-dependent kinase (CDK) inhibitor of the phosphate signaling (PHO) pathway. We also provide novel mechanistic insight into the role of IP7 in PHO pathway regulation by demonstrating that IP7 functions as an intermolecular "glue" to stabilize Pho81 association with Pho85/Pho80 and, hence, promote PHO pathway activation and phosphate acquisition. Blocking IP7-Pho81 interaction using site-directed mutagenesis led to a dramatic loss of fungal virulence in a mouse infection model, and the effect was similar to that observed following PHO81 gene deletion, highlighting the key importance of Pho81 in fungal virulence. Furthermore, our findings provide additional evidence of evolutionary divergence in PHO pathway regulation in fungi by demonstrating that IP7 isomers have evolved different roles in PHO pathway control in C. neoformans and nonpathogenic yeast.IMPORTANCE Invasive fungal diseases pose a serious threat to human health globally with >1.5 million deaths occurring annually, 180,000 of which are attributable to the AIDS-related pathogen, Cryptococcus neoformans Here, we demonstrate that interaction of the inositol pyrophosphate, IP7, with the CDK inhibitor protein, Pho81, is instrumental in promoting fungal virulence. IP7-Pho81 interaction stabilizes Pho81 association with other CDK complex components to promote PHO pathway activation and phosphate acquisition. Our data demonstrating that blocking IP7-Pho81 interaction or preventing Pho81 production leads to a dramatic loss in fungal virulence, coupled with Pho81 having no homologue in humans, highlights Pho81 function as a potential target for the development of urgently needed antifungal drugs.
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54
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Wang Z, Jork N, Bittner T, Wang H, Jessen HJ, Shears SB. Rapid stimulation of cellular Pi uptake by the inositol pyrophosphate InsP 8 induced by its photothermal release from lipid nanocarriers using a near infra-red light-emitting diode. Chem Sci 2020; 11:10265-10278. [PMID: 33659052 PMCID: PMC7891704 DOI: 10.1039/d0sc02144j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 09/07/2020] [Indexed: 11/21/2022] Open
Abstract
Inositol pyrophosphates (PP-InsPs), including diphospho-myo-inositol pentakisphosphate (5-InsP7) and bis-diphospho-myo-inositol tetrakisphosphate (1,5-InsP8), are highly polar, membrane-impermeant signaling molecules that control many homeostatic responses to metabolic and bioenergetic imbalance. To delineate their molecular activities, there is an increasing need for a toolbox of methodologies for real-time modulation of PP-InsP levels inside large populations of cultured cells. Here, we describe procedures to package PP-InsPs into thermosensitive phospholipid nanocapsules that are impregnated with a near infra-red photothermal dye; these liposomes are readily accumulated into cultured cells. The PP-InsPs remain trapped inside the liposomes until the cultures are illuminated with a near infra-red light-emitting diode (LED) which permeabilizes the liposomes to promote PP-InsP release. Additionally, so as to optimize these procedures, a novel stably fluorescent 5-InsP7 analogue (i.e., 5-FAM-InsP7) was synthesized with the assistance of click-chemistry; the delivery and deposition of the analogue inside cells was monitored by flow cytometry and by confocal microscopy. We describe quantitatively-controlled PP-InsP release inside cells within 5 min of LED irradiation, without measurable effect upon cell integrity, using a collimated 22 mm beam that can irradiate up to 106 cultured cells. Finally, to interrogate the biological value of these procedures, we delivered 1,5-InsP8 into HCT116 cells and showed it to dose-dependently stimulate the rate of [33P]-Pi uptake; these observations reveal a rheostatic range of concentrations over which 1,5-InsP8 is biologically functional in Pi homeostasis.
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Affiliation(s)
- Zhenzhen Wang
- Signal Transduction Laboratory , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , NC 27709 , USA . ; Tel: +1-984-287-3483
| | - Nikolaus Jork
- Institute of Organic Chemistry , CIBSS , Center for Integrative Biological Signalling Studies , University of Freiburg , 79104 Freiburg , Germany
| | - Tamara Bittner
- Institute of Organic Chemistry , CIBSS , Center for Integrative Biological Signalling Studies , University of Freiburg , 79104 Freiburg , Germany
| | - Huanchen Wang
- Signal Transduction Laboratory , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , NC 27709 , USA . ; Tel: +1-984-287-3483
| | - Henning J Jessen
- Institute of Organic Chemistry , CIBSS , Center for Integrative Biological Signalling Studies , University of Freiburg , 79104 Freiburg , Germany
| | - Stephen B Shears
- Signal Transduction Laboratory , National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , NC 27709 , USA . ; Tel: +1-984-287-3483
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55
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Trilisenko L, Valiakhmetov A, Kulakovskaya T. Phosphate efflux as a test of plasma membrane leakage in Saccharomyces cerevisiae cells. Can J Microbiol 2020; 67:226-230. [PMID: 32910859 DOI: 10.1139/cjm-2020-0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plasma membrane integrity is a key to cell viability. Currently, the main approach to assessing plasma membrane integrity is the detection of penetration of special dyes, such as trypan blue and propidium iodide, into the cells. However, this method needs expensive equipment: a fluorescent microscope or a flow cytometer. Besides, staining with propidium iodide occasionally gives false-positive results. Here, we suggest the phosphate (Pi) leakage assay as an approach to assess the increase in permeability of the plasma membrane of yeast cells. We studied the dependence of phosphate efflux and uptake into Saccharomyces cerevisiae cells on the composition of the incubation medium, time, and ambient pH. The difference in optimal conditions for these processes suggests that Pi efflux is not conducted by the Pi uptake system. The Pi efflux in water correlated with the proportion of cells stained with propidium iodide. This indicated that Pi efflux is associated with cytoplasmic membrane disruption in a portion of the yeast cell population. The assay of Pi efflux was used to evaluate membrane disruption in S. cerevisiae cells treated with some heavy metal ions and detergents.
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Affiliation(s)
- Ludmila Trilisenko
- FRC Pushchino Center for Biological Research, Russian Academy of Sciences, Skryabin Institute of Biochemistry and Physiology of Microorganisms, pr. Nauki 5, Pushchino, 142290 Russia.,FRC Pushchino Center for Biological Research, Russian Academy of Sciences, Skryabin Institute of Biochemistry and Physiology of Microorganisms, pr. Nauki 5, Pushchino, 142290 Russia
| | - Airat Valiakhmetov
- FRC Pushchino Center for Biological Research, Russian Academy of Sciences, Skryabin Institute of Biochemistry and Physiology of Microorganisms, pr. Nauki 5, Pushchino, 142290 Russia.,FRC Pushchino Center for Biological Research, Russian Academy of Sciences, Skryabin Institute of Biochemistry and Physiology of Microorganisms, pr. Nauki 5, Pushchino, 142290 Russia
| | - Tatiana Kulakovskaya
- FRC Pushchino Center for Biological Research, Russian Academy of Sciences, Skryabin Institute of Biochemistry and Physiology of Microorganisms, pr. Nauki 5, Pushchino, 142290 Russia.,FRC Pushchino Center for Biological Research, Russian Academy of Sciences, Skryabin Institute of Biochemistry and Physiology of Microorganisms, pr. Nauki 5, Pushchino, 142290 Russia
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56
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Austin S, Mayer A. Phosphate Homeostasis - A Vital Metabolic Equilibrium Maintained Through the INPHORS Signaling Pathway. Front Microbiol 2020; 11:1367. [PMID: 32765429 PMCID: PMC7381174 DOI: 10.3389/fmicb.2020.01367] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022] Open
Abstract
Cells face major changes in demand for and supply of inorganic phosphate (Pi). Pi is often a limiting nutrient in the environment, particularly for plants and microorganisms. At the same time, the need for phosphate varies, establishing conflicts of goals. Cells experience strong peaks of Pi demand, e.g., during the S-phase, when DNA, a highly abundant and phosphate-rich compound, is duplicated. While cells must satisfy these Pi demands, they must safeguard themselves against an excess of Pi in the cytosol. This is necessary because Pi is a product of all nucleotide-hydrolyzing reactions. An accumulation of Pi shifts the equilibria of these reactions and reduces the free energy that they can provide to drive endergonic metabolic reactions. Thus, while Pi starvation may simply retard growth and division, an elevated cytosolic Pi concentration is potentially dangerous for cells because it might stall metabolism. Accordingly, the consequences of perturbed cellular Pi homeostasis are severe. In eukaryotes, they range from lethality in microorganisms such as yeast (Sethuraman et al., 2001; Hürlimann, 2009), severe growth retardation and dwarfism in plants (Puga et al., 2014; Liu et al., 2015; Wild et al., 2016) to neurodegeneration or renal Fanconi syndrome in humans (Legati et al., 2015; Ansermet et al., 2017). Intracellular Pi homeostasis is thus not only a fundamental topic of cell biology but also of growing interest for medicine and agriculture.
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Affiliation(s)
- Sisley Austin
- Département de Biochimie, Université de Lausanne, Lausanne, Switzerland
| | - Andreas Mayer
- Département de Biochimie, Université de Lausanne, Lausanne, Switzerland
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57
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López-Sánchez U, Tury S, Nicolas G, Wilson MS, Jurici S, Ayrignac X, Courgnaud V, Saiardi A, Sitbon M, Battini JL. Interplay between primary familial brain calcification-associated SLC20A2 and XPR1 phosphate transporters requires inositol polyphosphates for control of cellular phosphate homeostasis. J Biol Chem 2020; 295:9366-9378. [PMID: 32393577 PMCID: PMC7363132 DOI: 10.1074/jbc.ra119.011376] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 05/09/2020] [Indexed: 12/19/2022] Open
Abstract
Solute carrier family 20 member 2 (SLC20A2) and xenotropic and polytropic retrovirus receptor 1 (XPR1) are transporters with phosphate uptake and efflux functions, respectively. Both are associated with primary familial brain calcification (PFBC), a genetic disease characterized by cerebral calcium-phosphate deposition and associated with neuropsychiatric symptoms. The association of the two transporters with the same disease suggests that they jointly regulate phosphate fluxes and cellular homeostasis, but direct evidence is missing. Here, we found that cross-talk between SLC20A2 and XPR1 regulates phosphate homeostasis, and we identified XPR1 as a key inositol polyphosphate (IP)-dependent regulator of this process. We found that overexpression of WT SLC20A2 increased phosphate uptake, as expected, but also unexpectedly increased phosphate efflux, whereas PFBC-associated SLC20A2 variants did not. Conversely, SLC20A2 depletion decreased phosphate uptake only slightly, most likely compensated for by the related SLC20A1 transporter, but strongly decreased XPR1-mediated phosphate efflux. The SLC20A2-XPR1 axis maintained constant intracellular phosphate and ATP levels, which both increased in XPR1 KO cells. Elevated ATP levels are a hallmark of altered inositol pyrophosphate (PP-IP) synthesis, and basal ATP levels were restored after phosphate efflux rescue with WT XPR1 but not with XPR1 harboring a mutated PP-IP-binding pocket. Accordingly, inositol hexakisphosphate kinase 1-2 (IP6K1-2) gene inactivation or IP6K inhibitor treatment abolished XPR1-mediated phosphate efflux regulation and homeostasis. Our findings unveil an SLC20A2-XPR1 interplay that depends on IPs such as PP-IPs and controls cellular phosphate homeostasis via the efflux route, and alteration of this interplay likely contributes to PFBC.
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Affiliation(s)
- Uriel López-Sánchez
- Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, CNRS, Montpellier, France.,Institut de Génétique Moléculaire de Montpellier (IGMM), Université de Montpellier, CNRS, Montpellier, France
| | - Sandrine Tury
- Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, CNRS, Montpellier, France
| | - Gaël Nicolas
- Normandie Univ, UNIROUEN, Inserm U1245, and Rouen University Hospital, Department of Genetics and CNR-MAJ, Normandy Center for Genomic and Personalized Medicine, Rouen, France
| | - Miranda S Wilson
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Snejana Jurici
- Department of Neurology, Perpignan Hospital, Perpignan, France
| | - Xavier Ayrignac
- Department of Neurology, Montpellier University Hospital, Montpellier, France
| | - Valérie Courgnaud
- Institut de Génétique Moléculaire de Montpellier (IGMM), Université de Montpellier, CNRS, Montpellier, France
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Marc Sitbon
- Institut de Génétique Moléculaire de Montpellier (IGMM), Université de Montpellier, CNRS, Montpellier, France
| | - Jean-Luc Battini
- Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, CNRS, Montpellier, France .,Institut de Génétique Moléculaire de Montpellier (IGMM), Université de Montpellier, CNRS, Montpellier, France
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58
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Sanz-Luque E, Bhaya D, Grossman AR. Polyphosphate: A Multifunctional Metabolite in Cyanobacteria and Algae. FRONTIERS IN PLANT SCIENCE 2020; 11:938. [PMID: 32670331 PMCID: PMC7332688 DOI: 10.3389/fpls.2020.00938] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/09/2020] [Indexed: 05/19/2023]
Abstract
Polyphosphate (polyP), a polymer of orthophosphate (PO4 3-) of varying lengths, has been identified in all kingdoms of life. It can serve as a source of chemical bond energy (phosphoanhydride bond) that may have been used by biological systems prior to the evolution of ATP. Intracellular polyP is mainly stored as granules in specific vacuoles called acidocalcisomes, and its synthesis and accumulation appear to impact a myriad of cellular functions. It serves as a reservoir for inorganic PO4 3- and an energy source for fueling cellular metabolism, participates in maintaining adenylate and metal cation homeostasis, functions as a scaffold for sequestering cations, exhibits chaperone function, covalently binds to proteins to modify their activity, and enables normal acclimation of cells to stress conditions. PolyP also appears to have a role in symbiotic and parasitic associations, and in higher eukaryotes, low polyP levels seem to impact cancerous proliferation, apoptosis, procoagulant and proinflammatory responses and cause defects in TOR signaling. In this review, we discuss the metabolism, storage, and function of polyP in photosynthetic microbes, which mostly includes research on green algae and cyanobacteria. We focus on factors that impact polyP synthesis, specific enzymes required for its synthesis and degradation, sequestration of polyP in acidocalcisomes, its role in cellular energetics, acclimation processes, and metal homeostasis, and then transition to its potential applications for bioremediation and medical purposes.
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Affiliation(s)
- Emanuel Sanz-Luque
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
- Department of Biochemistry and Molecular Biology, University of Cordoba, Cordoba, Spain
| | - Devaki Bhaya
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
| | - Arthur R. Grossman
- Department of Plant Biology, The Carnegie Institution for Science, Stanford, CA, United States
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59
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Cridland C, Gillaspy G. Inositol Pyrophosphate Pathways and Mechanisms: What Can We Learn from Plants? Molecules 2020; 25:E2789. [PMID: 32560343 PMCID: PMC7356102 DOI: 10.3390/molecules25122789] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/11/2020] [Accepted: 06/13/2020] [Indexed: 11/25/2022] Open
Abstract
The ability of an organism to maintain homeostasis in changing conditions is crucial for growth and survival. Eukaryotes have developed complex signaling pathways to adapt to a readily changing environment, including the inositol phosphate (InsP) signaling pathway. In plants and humans the pyrophosphorylated inositol molecules, inositol pyrophosphates (PP-InsPs), have been implicated in phosphate and energy sensing. PP-InsPs are synthesized from the phosphorylation of InsP6, the most abundant InsP. The plant PP-InsP synthesis pathway is similar but distinct from that of the human, which may reflect differences in how molecules such as Ins(1,4,5)P3 and InsP6 function in plants vs. animals. In addition, PP-InsPs can potentially interact with several major signaling proteins in plants, suggesting PP-InsPs play unique signaling roles via binding to protein partners. In this review, we will compare the biosynthesis and role of PP-InsPs in animals and plants, focusing on three central themes: InsP6 synthesis pathways, synthesis and regulation of the PP-InsPs, and function of a specific protein domain called the Syg1, Pho1, Xpr1 (SPX ) domain in binding PP-InsPs and regulating inorganic phosphate (Pi) sensing. This review will provide novel insights into the biosynthetic pathway and bioactivity of these key signaling molecules in plant and human systems.
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Affiliation(s)
| | - Glenda Gillaspy
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA;
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60
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Abstract
Phosphate is an essential nutrient for life and is a critical component of bone formation, a major signaling molecule, and structural component of cell walls. Phosphate is also a component of high-energy compounds (i.e., AMP, ADP, and ATP) and essential for nucleic acid helical structure (i.e., RNA and DNA). Phosphate plays a central role in the process of mineralization, normal serum levels being associated with appropriate bone mineralization, while high and low serum levels are associated with soft tissue calcification. The serum concentration of phosphate and the total body content of phosphate are highly regulated, a process that is accomplished by the coordinated effort of two families of sodium-dependent transporter proteins. The three isoforms of the SLC34 family (SLC34A1-A3) show very restricted tissue expression and regulate intestinal absorption and renal excretion of phosphate. SLC34A2 also regulates the phosphate concentration in multiple lumen fluids including milk, saliva, pancreatic fluid, and surfactant. Both isoforms of the SLC20 family exhibit ubiquitous expression (with some variation as to which one or both are expressed), are regulated by ambient phosphate, and likely serve the phosphate needs of the individual cell. These proteins exhibit similarities to phosphate transporters in nonmammalian organisms. The proteins are nonredundant as mutations in each yield unique clinical presentations. Further research is essential to understand the function, regulation, and coordination of the various phosphate transporters, both the ones described in this review and the phosphate transporters involved in intracellular transport.
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Affiliation(s)
- Nati Hernando
- University of Zurich-Irchel, Institute of Physiology, Zurich, Switzerland; Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky; and Robley Rex VA Medical Center, Louisville, Kentucky
| | - Kenneth Gagnon
- University of Zurich-Irchel, Institute of Physiology, Zurich, Switzerland; Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky; and Robley Rex VA Medical Center, Louisville, Kentucky
| | - Eleanor Lederer
- University of Zurich-Irchel, Institute of Physiology, Zurich, Switzerland; Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky; and Robley Rex VA Medical Center, Louisville, Kentucky
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61
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Thakur S, Goswami K, Rao P, Kaushik S, Singh BP, Kain P, Asthana S, Bhattacharjee S, Guchhait P, Eswaran SV. Fluoresceinated Aminohexanol Tethered Inositol Hexakisphosphate: Studies on Arabidopsis thaliana and Drosophila melanogaster and Docking with 2P1M Receptor. ACS OMEGA 2020; 5:9585-9597. [PMID: 32363311 PMCID: PMC7191843 DOI: 10.1021/acsomega.0c00961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/01/2020] [Indexed: 05/17/2023]
Abstract
Inositol hexakisphosphate (InsP6; phytic acid) is considered as the second messenger and plays a very important role in plants, animals, and human beings. It is the principal storage form of phosphorus in many plant tissues, especially in dry fruits, bran, and seeds. The resulting anion is a colorless species that plays a critical role in nutrition and is believed to cure many diseases. A fluoresceinated aminohexanol tethered inositol hexakisphosphate (III) had been synthesized earlier involving many complicated steps. We describe here a simple two-step synthesis of (III) and its characterization using different techniques such as matrix-assisted laser desorption ionization mass spectrometry, tandem mass spectrometry, and Fourier transform infrared, ultraviolet-visible, ultraviolet-fluorescence, 1H nuclear magnetic resonance (NMR), and two-dimensional NMR spectroscopies. The effect of (III) has been investigated in the model systems, Arabidopsis thaliana and Drosophila melanogaster. Using Schrodinger software, computational studies on the binding of (III) with the protein 2P1M (Auxin-receptor TIR1-adaptor ASK1 complex) has revealed strong binding propensity with this compound. These studies on the fluoresceinated tethered phytic acid could have far reaching implications on its efficacy for human health and treatment of diseases (cancer/tumor and glioblastoma) and for understanding phosphorous recycling in the environment, especially for plant systems.
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Affiliation(s)
- Sujeet
Kumar Thakur
- TERI
School of Advanced Studies, Plot No. 10, Vasant Kunj Institutional Area, Vasant
Kunj, Institutional Area, New Delhi 110070, India
| | - Krishnendu Goswami
- Regional
Centre for Biotechnology (RCB), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Pallavi Rao
- Amity
University, Noida, 201313 Uttar Pradesh, India
| | - Shivam Kaushik
- Regional
Centre for Biotechnology (RCB), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Bhanu Pratap Singh
- Translational
Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Pinky Kain
- Regional
Centre for Biotechnology (RCB), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Shailendra Asthana
- Translational
Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Saikat Bhattacharjee
- Regional
Centre for Biotechnology (RCB), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Prasenjit Guchhait
- Regional
Centre for Biotechnology (RCB), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon
Expressway, Faridabad, 121001 Haryana, India
| | - Sambasivan V. Eswaran
- Teri
Deakin Nano Biotechnology Centre (TDNBC), Teri Gram, Gwal Pahari, Gurgaon- Faridabad Expressway, Gurugram, 122002 Haryana, India
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62
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Phosphoric Metabolites Link Phosphate Import and Polysaccharide Biosynthesis for Candida albicans Cell Wall Maintenance. mBio 2020; 11:mBio.03225-19. [PMID: 32184254 PMCID: PMC7078483 DOI: 10.1128/mbio.03225-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Candida species cause hundreds of thousands of invasive infections with high mortality each year. Developing novel antifungal agents is challenging due to the many similarities between fungal and human cells. Maintaining phosphate balance is essential for all organisms but is achieved completely differently by fungi and humans. A protein that imports phosphate into fungal cells, Pho84, is not present in humans and is required for normal cell wall stress resistance and cell wall integrity signaling in C. albicans. Nucleotide sugars, which are phosphate-containing building block molecules for construction of the cell wall, are diminished in cells lacking Pho84. Cell wall-constructing enzymes may be slowed by lack of these building blocks, in addition to being inhibited by drugs. Combined targeting of Pho84 and cell wall-constructing enzymes may provide a strategy for antifungal therapy by which two sequential steps of cell wall maintenance are blocked for greater potency. The Candida albicans high-affinity phosphate transporter Pho84 is required for normal Target of Rapamycin (TOR) signaling, oxidative stress resistance, and virulence of this fungal pathogen. It also contributes to C. albicans’ tolerance of two antifungal drug classes, polyenes and echinocandins. Echinocandins inhibit biosynthesis of a major cell wall component, beta-1,3-glucan. Cells lacking Pho84 were hypersensitive to other forms of cell wall stress beyond echinocandin exposure, while their cell wall integrity signaling response was weak. Metabolomics experiments showed that levels of phosphoric intermediates, including nucleotides like ATP and nucleotide sugars, were low in pho84 mutant compared to wild-type cells recovering from phosphate starvation. Nonphosphoric precursors like nucleobases and nucleosides were elevated. Outer cell wall phosphomannan biosynthesis requires a nucleotide sugar, GDP-mannose. The nucleotide sugar UDP-glucose is the substrate of enzymes that synthesize two major structural cell wall polysaccharides, beta-1,3- and beta-1,6-glucan. Another nucleotide sugar, UDP-N-acetylglucosamine, is the substrate of chitin synthases which produce a stabilizing component of the intercellular septum and of lateral cell walls. Lack of Pho84 activity, and phosphate starvation, potentiated pharmacological or genetic perturbation of these enzymes. We posit that low substrate concentrations of beta-d-glucan- and chitin synthases, together with pharmacologic inhibition of their activity, diminish enzymatic reaction rates as well as the yield of their cell wall-stabilizing products. Phosphate import is not conserved between fungal and human cells, and humans do not synthesize beta-d-glucans or chitin. Hence, inhibiting these processes simultaneously could yield potent antifungal effects with low toxicity to humans.
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Prieto JA, Estruch F, Córcoles-Sáez I, Del Poeta M, Rieger R, Stenzel I, Randez-Gil F. Pho85 and PI(4,5)P 2 regulate different lipid metabolic pathways in response to cold. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158557. [PMID: 31678512 PMCID: PMC7254492 DOI: 10.1016/j.bbalip.2019.158557] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/25/2019] [Accepted: 10/26/2019] [Indexed: 12/11/2022]
Abstract
Lipid homeostasis allows cells to adjust membrane biophysical properties in response to changes in environmental conditions. In the yeast Saccharomyces cerevisiae, a downward shift in temperature from an optimal reduces membrane fluidity, which triggers a lipid remodeling of the plasma membrane. How changes in membrane fluidity are perceived, and how the abundance and composition of different lipid classes is properly balanced, remain largely unknown. Here, we show that the levels of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], the most abundant plasma membrane phosphoinositide, drop rapidly in response to a downward shift in temperature. This change triggers a signaling cascade transmitted to cytosolic diphosphoinositol phosphate derivatives, among them 5-PP-IP4 and 1-IP7, that exert regulatory functions on genes involved in the inositol and phospholipids (PLs) metabolism, and inhibit the activity of the protein kinase Pho85. Consistent with this, cold exposure triggers a specific program of neutral lipids and PLs changes. Furthermore, we identified Pho85 as playing a key role in controlling the synthesis of long-chain bases (LCBs) via the Ypk1-Orm2 regulatory circuit. We conclude that Pho85 orchestrates a coordinated response of lipid metabolic pathways that ensure yeast thermal adaptation.
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Affiliation(s)
- Jose A Prieto
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino, 7, 46980 Paterna, Valencia, Spain
| | - Francisco Estruch
- Departament of Biochemistry and Molecular Biology, Universitat de València, Dr. Moliner 50, Burjassot 46100, Spain
| | - Isaac Córcoles-Sáez
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino, 7, 46980 Paterna, Valencia, Spain
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States of America; Veterans Administration Medical Center, Northport, NY, United States of America
| | - Robert Rieger
- Proteomics Center, Stony Brook University, Stony Brook, NY, United States of America
| | - Irene Stenzel
- Department of Cellular Biochemistry, Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
| | - Francisca Randez-Gil
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Avda. Agustín Escardino, 7, 46980 Paterna, Valencia, Spain.
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64
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Freed C, Adepoju O, Gillaspy G. Can Inositol Pyrophosphates Inform Strategies for Developing Low Phytate Crops? PLANTS (BASEL, SWITZERLAND) 2020; 9:E115. [PMID: 31963418 PMCID: PMC7020182 DOI: 10.3390/plants9010115] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 01/01/2023]
Abstract
Inositol pyrophosphates (PP-InsPs) are an emerging class of "high-energy" intracellular signaling molecules, containing one or two diphosphate groups attached to an inositol ring, that are connected with phosphate sensing, jasmonate signaling, and inositol hexakisphosphate (InsP6) storage in plants. While information regarding this new class of signaling molecules in plants is scarce, the enzymes responsible for their synthesis have recently been elucidated. This review focuses on InsP6 synthesis and its conversion into PP-InsPs, containing seven and eight phosphate groups (InsP7 and InsP8). These steps involve two types of enzymes: the ITPKs that phosphorylate InsP6 to InsP7, and the PPIP5Ks that phosphorylate InsP7 to InsP8. This review also considers the potential roles of PP-InsPs in plant hormone and inorganic phosphate (Pi) signaling, along with an emerging role in bioenergetic homeostasis. PP-InsP synthesis and signaling are important for plant breeders to consider when developing strategies that reduce InsP6 in plants, as this will likely also reduce PP-InsPs. Thus, this review is primarily intended to bridge the gap between the basic science aspects of PP-InsP synthesis/signaling and breeding/engineering strategies to fortify foods by reducing InsP6.
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Affiliation(s)
| | | | - Glenda Gillaspy
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA (O.A.)
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65
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Lorenzo‐Orts L, Couto D, Hothorn M. Identity and functions of inorganic and inositol polyphosphates in plants. THE NEW PHYTOLOGIST 2020; 225:637-652. [PMID: 31423587 PMCID: PMC6973038 DOI: 10.1111/nph.16129] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/22/2019] [Indexed: 05/08/2023]
Abstract
Inorganic polyphosphates (polyPs) and inositol pyrophosphates (PP-InsPs) form important stores of inorganic phosphate and can act as energy metabolites and signaling molecules. Here we review our current understanding of polyP and inositol phosphate (InsP) metabolism and physiology in plants. We outline methods for polyP and InsP detection, discuss the known plant enzymes involved in their synthesis and breakdown, and summarize the potential physiological and signaling functions for these enigmatic molecules in plants.
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Affiliation(s)
- Laura Lorenzo‐Orts
- Structural Plant Biology LaboratoryDepartment of Botany and Plant BiologyUniversity of Geneva30 Quai E. AnsermetGeneva1211Switzerland
| | - Daniel Couto
- Structural Plant Biology LaboratoryDepartment of Botany and Plant BiologyUniversity of Geneva30 Quai E. AnsermetGeneva1211Switzerland
| | - Michael Hothorn
- Structural Plant Biology LaboratoryDepartment of Botany and Plant BiologyUniversity of Geneva30 Quai E. AnsermetGeneva1211Switzerland
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66
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Sanchez AM, Garg A, Shuman S, Schwer B. Inositol pyrophosphates impact phosphate homeostasis via modulation of RNA 3' processing and transcription termination. Nucleic Acids Res 2019; 47:8452-8469. [PMID: 31276588 PMCID: PMC6895273 DOI: 10.1093/nar/gkz567] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/10/2019] [Accepted: 07/03/2019] [Indexed: 12/24/2022] Open
Abstract
Fission yeast phosphate acquisition genes pho1, pho84, and tgp1 are repressed in phosphate-rich medium by transcription of upstream lncRNAs. Here, we show that phosphate homeostasis is subject to metabolite control by inositol pyrophosphates (IPPs), exerted through the 3'-processing/termination machinery and the Pol2 CTD code. Increasing IP8 (via Asp1 IPP pyrophosphatase mutation) de-represses the PHO regulon and leads to precocious termination of prt lncRNA synthesis. pho1 de-repression by IP8 depends on cleavage-polyadenylation factor (CPF) subunits, termination factor Rhn1, and the Thr4 letter of the CTD code. pho1 de-repression by mutation of the Ser7 CTD letter depends on IP8. Simultaneous inactivation of the Asp1 and Aps1 IPP pyrophosphatases is lethal, but this lethality is suppressed by mutations of CPF subunits Ppn1, Swd22, Ssu72, and Ctf1 and CTD mutation T4A. Failure to synthesize IP8 (via Asp1 IPP kinase mutation) results in pho1 hyper-repression. Synthetic lethality of asp1Δ with Ppn1, Swd22, and Ssu72 mutations argues that IP8 plays an important role in essential 3'-processing/termination events, albeit in a manner genetically redundant to CPF. Transcriptional profiling delineates an IPP-responsive regulon composed of genes overexpressed when IP8 levels are increased. Our results establish a novel role for IPPs in cell physiology.
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Affiliation(s)
- Ana M Sanchez
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Angad Garg
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Beate Schwer
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065, USA
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67
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Randall TA, Gu C, Li X, Wang H, Shears SB. A two-way switch for inositol pyrophosphate signaling: Evolutionary history and biological significance of a unique, bifunctional kinase/phosphatase. Adv Biol Regul 2019; 75:100674. [PMID: 31776069 DOI: 10.1016/j.jbior.2019.100674] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 10/30/2019] [Accepted: 11/06/2019] [Indexed: 11/25/2022]
Abstract
The inositol pyrophosphates (PP-InsPs) are a unique subgroup of intracellular signals with diverse functions, many of which can be viewed as reflecting an overarching role in metabolic homeostasis. Thus, considerable attention is paid to the enzymes that synthesize and metabolize the PP-InsPs. One of these enzyme families - the diphosphoinositol pentakisphosphate kinases (PPIP5Ks) - provides an extremely rare example of separate kinase and phosphatase activities being present within the same protein. Herein, we review the current state of structure/function insight into the PPIP5Ks, the separate specialized activities of the two metazoan PPIP5K genes, and we describe a phylogenetic analysis that places PPIP5K evolutionary origin within the Excavata, the very earliest of eukaryotes. These different aspects of PPIP5K biology are placed in the context of a single, overriding question. Why are they bifunctional: i.e., what is the particular significance of the ability to turn PP-InsP signaling on or off from two separate 'switches' in a single protein?
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Affiliation(s)
- Thomas A Randall
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Chunfang Gu
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Xingyao Li
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Huanchen Wang
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Stephen B Shears
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA.
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68
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Dong J, Ma G, Sui L, Wei M, Satheesh V, Zhang R, Ge S, Li J, Zhang TE, Wittwer C, Jessen HJ, Zhang H, An GY, Chao DY, Liu D, Lei M. Inositol Pyrophosphate InsP 8 Acts as an Intracellular Phosphate Signal in Arabidopsis. MOLECULAR PLANT 2019; 12:1463-1473. [PMID: 31419530 DOI: 10.1016/j.molp.2019.08.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 08/04/2019] [Accepted: 08/06/2019] [Indexed: 05/21/2023]
Abstract
The maintenance of cellular phosphate (Pi) homeostasis is of great importance in living organisms. The SPX domain-containing protein 1 (SPX1) proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status. The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants, however, remains to be identified, as Pi itself does not bind to the SPX domain. Here, we report the identification of the inositol pyrophosphate InsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis. Polyacrylamide gel electrophoresis profiling of InsPs revealed that InsP8 level positively correlates with cellular Pi concentration. We demonstrated that the homologs of diphosphoinositol pentakisphosphate kinase (PPIP5K), VIH1 and VIH2, function redundantly to synthesize InsP8, and that the vih1 vih2 double mutant overaccumulates Pi. SPX1 directly interacts with PHR1, the central regulator of Pi starvation responses, to inhibit its function under Pi-replete conditions. However, this interaction is compromised in the vih1 vih2 double mutant, resulting in the constitutive induction of Pi starvation-induced genes, indicating that plant cells cannot sense cellular Pi status without InsP8. Furthermore, we showed that InsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1. Collectively, our study suggests that InsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.
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Affiliation(s)
- Jinsong Dong
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Guojie Ma
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology & Ecology, Chinese Academic of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liqian Sui
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Mengwei Wei
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Viswanathan Satheesh
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Ruyue Zhang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shenghong Ge
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinkai Li
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tong-En Zhang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Christopher Wittwer
- Institute of Organic Chemistry, Albert-Ludwigs University, Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Henning J Jessen
- Institute of Organic Chemistry, Albert-Ludwigs University, Freiburg, Albertstrasse 21, 79104 Freiburg, Germany; CIBSS - Centre for Integrative Biological Signalling Studies, Albert-Ludwigs University, Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Huiming Zhang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Guo-Yong An
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Dai-Yin Chao
- National Key Laboratory of Plant Molecular Genetics, CAS Centre for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology & Ecology, Chinese Academic of Sciences, Shanghai 200032, China
| | - Dong Liu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Mingguang Lei
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng 475004, China.
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69
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Kameoka H, Maeda T, Okuma N, Kawaguchi M. Structure-Specific Regulation of Nutrient Transport and Metabolism in Arbuscular Mycorrhizal Fungi. PLANT & CELL PHYSIOLOGY 2019; 60:2272-2281. [PMID: 31241164 DOI: 10.1093/pcp/pcz122] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 06/14/2019] [Indexed: 06/09/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with most land plants, mainly for the purpose of nutrient exchange. Many studies have revealed the regulation of processes in AMF, such as nutrient absorption from soil, metabolism and exchange with host plants, and the genes involved. However, the spatial regulation of the genes within the structures comprising each developmental stage is not well understood. Here, we demonstrate the structure-specific transcriptome of the model AMF species, Rhizophagus irregularis. We performed an ultra-low input RNA-seq analysis, SMART-seq2, comparing five extraradical structures, germ tubes, runner hyphae, branched absorbing structures (BAS), immature spores and mature spores. In addition, we reanalyzed the recently reported RNA-seq data comparing intraradical mycelium and arbuscule. Our analyses captured the distinct features of each structure and revealed the structure-specific expression patterns of genes related to nutrient transport and metabolism. Of note, the transcriptional profiles suggest distinct functions of BAS in nutrient absorption. These findings provide a comprehensive dataset to advance our understanding of the transcriptional dynamics of fungal nutrition in this symbiotic system.
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Affiliation(s)
- Hiromu Kameoka
- Division of Symbiotic Systems, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, Japan
| | - Taro Maeda
- Division of Symbiotic Systems, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, Japan
| | - Nao Okuma
- The Graduate University for Advanced Studies, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, Japan
| | - Masayoshi Kawaguchi
- Division of Symbiotic Systems, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, Japan
- The Graduate University for Advanced Studies, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, Japan
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70
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Crombez H, Motte H, Beeckman T. Tackling Plant Phosphate Starvation by the Roots. Dev Cell 2019; 48:599-615. [PMID: 30861374 DOI: 10.1016/j.devcel.2019.01.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 10/16/2018] [Accepted: 12/31/2018] [Indexed: 12/17/2022]
Abstract
Plant responses to phosphate deprivation encompass a wide range of strategies, varying from altering root system architecture, entering symbiotic interactions to excreting root exudates for phosphorous release, and recycling of internal phosphate. These processes are tightly controlled by a complex network of proteins that are specifically upregulated upon phosphate starvation. Although the different effects of phosphate starvation have been intensely studied, the full extent of its contribution to altered root system architecture remains unclear. In this review, we focus on the effect of phosphate starvation on the developmental processes that shape the plant root system and their underlying molecular pathways.
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Affiliation(s)
- Hanne Crombez
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, Ghent 9052, Belgium
| | - Hans Motte
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, Ghent 9052, Belgium
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, Ghent 9052, Belgium.
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71
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Zhu J, Lau K, Puschmann R, Harmel RK, Zhang Y, Pries V, Gaugler P, Broger L, Dutta AK, Jessen HJ, Schaaf G, Fernie AR, Hothorn LA, Fiedler D, Hothorn M. Two bifunctional inositol pyrophosphate kinases/phosphatases control plant phosphate homeostasis. eLife 2019; 8:43582. [PMID: 31436531 PMCID: PMC6731061 DOI: 10.7554/elife.43582] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 08/21/2019] [Indexed: 12/15/2022] Open
Abstract
Many eukaryotic proteins regulating phosphate (Pi) homeostasis contain SPX domains that are receptors for inositol pyrophosphates (PP-InsP), suggesting that PP-InsPs may regulate Pi homeostasis. Here we report that deletion of two diphosphoinositol pentakisphosphate kinases VIH1/2 impairs plant growth and leads to constitutive Pi starvation responses. Deletion of phosphate starvation response transcription factors partially rescues vih1 vih2 mutant phenotypes, placing diphosphoinositol pentakisphosphate kinases in plant Pi signal transduction cascades. VIH1/2 are bifunctional enzymes able to generate and break-down PP-InsPs. Mutations in the kinase active site lead to increased Pi levels and constitutive Pi starvation responses. ATP levels change significantly in different Pi growth conditions. ATP-Mg2+ concentrations shift the relative kinase and phosphatase activities of diphosphoinositol pentakisphosphate kinases in vitro. Pi inhibits the phosphatase activity of the enzyme. Thus, VIH1 and VIH2 relay changes in cellular ATP and Pi concentrations to changes in PP-InsP levels, allowing plants to maintain sufficient Pi levels.
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Affiliation(s)
- Jinsheng Zhu
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Kelvin Lau
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Robert Puschmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany.,Department of Chemistry, Humboldt Universität zu Berlin, Berlin, Germany
| | - Robert K Harmel
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany.,Department of Chemistry, Humboldt Universität zu Berlin, Berlin, Germany
| | - Youjun Zhang
- Max-Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany.,Center of Plant System Biology and Biotechnology, Plovdiv, Bulgaria
| | - Verena Pries
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, Bonn, Germany
| | - Philipp Gaugler
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, Bonn, Germany
| | - Larissa Broger
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Amit K Dutta
- Institute of Organic Chemistry, Freiburg im Breisgau, Germany
| | | | - Gabriel Schaaf
- Institute of Crop Science and Resource Conservation, Department of Plant Nutrition, University of Bonn, Bonn, Germany
| | - Alisdair R Fernie
- Max-Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Ludwig A Hothorn
- Institute of Biostatistics, Leibniz University, Hannover, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany.,Department of Chemistry, Humboldt Universität zu Berlin, Berlin, Germany
| | - Michael Hothorn
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
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72
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Lev S, Li C, Desmarini D, Sorrell TC, Saiardi A, Djordjevic JT. Fungal Kinases With a Sweet Tooth: Pleiotropic Roles of Their Phosphorylated Inositol Sugar Products in the Pathogenicity of Cryptococcus neoformans Present Novel Drug Targeting Opportunities. Front Cell Infect Microbiol 2019; 9:248. [PMID: 31380293 PMCID: PMC6660261 DOI: 10.3389/fcimb.2019.00248] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/26/2019] [Indexed: 12/17/2022] Open
Abstract
Invasive fungal pathogens cause more than 300 million serious human infections and 1.6 million deaths per year. A clearer understanding of the mechanisms by which these fungi cause disease is needed to identify novel targets for urgently needed therapies. Kinases are key components of the signaling and metabolic circuitry of eukaryotic cells, which include fungi, and kinase inhibition is currently being exploited for the treatment of human diseases. Inhibiting evolutionarily divergent kinases in fungal pathogens is a promising avenue for antifungal drug development. One such group of kinases is the phospholipase C1-dependent inositol polyphosphate kinases (IPKs), which act sequentially to transfer a phosphoryl group to a pre-phosphorylated inositol sugar (IP). This review focuses on the roles of fungal IPKs and their IP products in fungal pathogenicity, as determined predominantly from studies performed in the model fungal pathogen Cryptococcus neoformans, and compares them to what is known in non-pathogenic model fungi and mammalian cells to highlight potential drug targeting opportunities.
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Affiliation(s)
- Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Cecilia Li
- Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology-Public Health, NSW Health Pathology, Westmead Hospital, Sydney, NSW, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Tania C Sorrell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School-Westmead, The University of Sydney, Sydney, NSW, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, NSW, Australia
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73
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Goodenough U, Heiss AA, Roth R, Rusch J, Lee JH. Acidocalcisomes: Ultrastructure, Biogenesis, and Distribution in Microbial Eukaryotes. Protist 2019; 170:287-313. [DOI: 10.1016/j.protis.2019.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/26/2019] [Accepted: 05/01/2019] [Indexed: 12/19/2022]
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74
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Wilson MS, Jessen HJ, Saiardi A. The inositol hexakisphosphate kinases IP6K1 and -2 regulate human cellular phosphate homeostasis, including XPR1-mediated phosphate export. J Biol Chem 2019; 294:11597-11608. [PMID: 31186349 PMCID: PMC6663863 DOI: 10.1074/jbc.ra119.007848] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/04/2019] [Indexed: 01/08/2023] Open
Abstract
Phosphate's central role in most biochemical reactions in a living organism requires carefully maintained homeostasis. Although phosphate homeostasis in mammals has long been studied at the organismal level, the intracellular mechanisms controlling phosphate metabolism are not well-understood. Inositol pyrophosphates have emerged as important regulatory elements controlling yeast phosphate homeostasis. To verify whether inositol pyrophosphates also regulate mammalian cellular phosphate homeostasis, here we knocked out inositol hexakisphosphate kinase (IP6K) 1 and IP6K2 to generate human HCT116 cells devoid of any inositol pyrophosphates. Using PAGE and HPLC analysis, we observed that the IP6K1/2-knockout cells have nondetectable levels of the IP6-derived IP7 and IP8 and also exhibit reduced synthesis of the IP5-derived PP-IP4. Nucleotide analysis showed that the knockout cells contain increased amounts of ATP, whereas the Malachite green assay found elevated levels of free intracellular phosphate. Furthermore, [32Pi] pulse labeling experiments uncovered alterations in phosphate flux, with both import and export of phosphate being decreased in the knockout cells. Functional analysis of the phosphate exporter xenotropic and polytropic retrovirus receptor 1 (XPR1) revealed that it is regulated by inositol pyrophosphates, which can bind to its SPX domain. We conclude that IP6K1 and -2 together control inositol pyrophosphate metabolism and thereby physiologically regulate phosphate export and other aspects of mammalian cellular phosphate homeostasis.
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Affiliation(s)
- Miranda S Wilson
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Henning J Jessen
- Institute of Organic Chemistry, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
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75
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Abstract
Phosphorous is important for life but often limiting for plants. The symbiotic pathway of phosphate uptake via arbuscular mycorrhizal fungi (AMF) is evolutionarily ancient and today occurs in natural and agricultural ecosystems alike. Plants capable of this symbiosis can obtain up to all of the phosphate from symbiotic fungi, and this offers potential means to develop crops less dependent on unsustainable P fertilizers. Here, we review the mechanisms and insights gleaned from the fine-tuned signal exchanges that orchestrate the intimate mutualistic symbiosis between plants and AMF. As the currency of trade, nutrients have signaling functions beyond being the nutritional goal of mutualism. We propose that such signaling roles and metabolic reprogramming may represent commitments for a mutualistic symbiosis that act across the stages of symbiosis development.
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Affiliation(s)
- Chai Hao Chiu
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Uta Paszkowski
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
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76
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Kim J, Darè E, Rajasekaran SS, Ryu SH, Berggren PO, Barker CJ. Inositol pyrophosphates and Akt/PKB: Is the pancreatic β-cell the exception to the rule? Cell Signal 2019; 58:131-136. [DOI: 10.1016/j.cellsig.2019.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 01/30/2019] [Accepted: 02/07/2019] [Indexed: 12/14/2022]
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77
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Murry R, Kniemeyer O, Krause K, Saiardi A, Kothe E. Crosstalk between Ras and inositol phosphate signaling revealed by lithium action on inositol monophosphatase in Schizophyllum commune. Adv Biol Regul 2019; 72:78-88. [PMID: 30639095 PMCID: PMC6520614 DOI: 10.1016/j.jbior.2019.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 12/31/2018] [Accepted: 01/02/2019] [Indexed: 06/09/2023]
Abstract
Mushroom forming basidiomycete Schizophyllum commune has been used as a tractable model organism to study fungal sexual development. Ras signaling activation via G-protein-coupled receptors (GPCRs) has been postulated to play a significant role in the mating and development of S. commune. In this study, a crosstalk between Ras signaling and inositol phosphate signaling by inositol monophosphatase (IMPase) is revealed. Constitutively active Ras1 leads to the repression of IMPase transcription and lithium action on IMPase activity is compensated by the induction of IMPase at transcriptome level. Astonishingly, in S. commune lithium induces a considerable shift to inositol phosphate metabolism leading to a massive increase in the level of higher phosphorylated inositol species up to the inositol pyrophosphates. The lithium induced metabolic changes are not observable in a constitutively active Ras1 mutant. In addition to that, proteome profile helps us to elucidate an overview of lithium action to the broad aspect of fungal metabolism and cellular signaling. Taken together, these findings imply a crosstalk between Ras and inositol phosphate signaling.
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Affiliation(s)
- Reyna Murry
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany
| | - Olaf Kniemeyer
- Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute Jena, Germany
| | - Katrin Krause
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany
| | - Adolfo Saiardi
- Medical Research Council (MRC) Laboratory for Molecular Cell Biology, Department of Biochemistry and Molecular Biology, University College London, London, UK.
| | - Erika Kothe
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.
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78
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Motte H, Vanneste S, Beeckman T. Molecular and Environmental Regulation of Root Development. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:465-488. [PMID: 30822115 DOI: 10.1146/annurev-arplant-050718-100423] [Citation(s) in RCA: 169] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In order to optimally establish their root systems, plants are endowed with several mechanisms to use at distinct steps during their development. In this review, we zoom in on the major processes involved in root development and detail important new insights that have been generated in recent studies, mainly using the Arabidopsis root as a model. First, we discuss new insights in primary root development with the characterization of tissue-specific transcription factor complexes and the identification of non-cell-autonomous control mechanisms in the root apical meristem. Next, root branching is discussed by focusing on the earliest steps in the development of a new lateral root and control of its postemergence growth. Finally, we discuss the impact of phosphate, nitrogen, and water availability on root development and summarize current knowledge about the major molecular mechanisms involved.
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Affiliation(s)
- Hans Motte
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium;
| | - Steffen Vanneste
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium;
- Lab of Plant Growth Analysis, Ghent University Global Campus, Incheon 21985, Republic of Korea
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium;
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79
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De Rango F, Crocco P, Iannone F, Saiardi A, Passarino G, Dato S, Rose G. Inositol Polyphosphate Multikinase ( IPMK), a Gene Coding for a Potential Moonlighting Protein, Contributes to Human Female Longevity. Genes (Basel) 2019; 10:genes10020125. [PMID: 30744060 PMCID: PMC6410091 DOI: 10.3390/genes10020125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/04/2019] [Accepted: 02/04/2019] [Indexed: 01/03/2023] Open
Abstract
Biogerontological research highlighted a complex and dynamic connection between aging, health and longevity, partially determined by genetic factors. Multifunctional proteins with moonlighting features, by integrating different cellular activities in the space and time, may explain part of this complexity. Inositol Polyphosphate Multikinase (IPMK) is a potential moonlighting protein performing multiple unrelated functions. Initially identified as a key enzyme for inositol phosphates synthesis, small messengers regulating many aspects of cell physiology, IPMK is now implicated in a number of metabolic pathways affecting the aging process. IPMK regulates basic transcription, telomere homeostasis, nutrient-sensing, metabolism and oxidative stress. Here, we tested the hypothesis that the genetic variability of IPMK may affect human longevity. Single-SNP (single nuclear polymorphism), haplotype-based association tests as well as survival analysis pointed to the relevance of six out of fourteen genotyped SNPs for female longevity. In particular, haplotype analysis refined the association highlighting two SNPs, rs2790234 and rs6481383, as major contributing variants for longevity in women. Our work, the first to investigate the association between variants of IPMK and longevity, supports IPMK as a novel gender-specific genetic determinant of human longevity, playing a role in the complex network of genetic factors involved in human survival.
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Affiliation(s)
- Francesco De Rango
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
| | - Paolina Crocco
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
| | - Francesca Iannone
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
| | - Giuseppe Passarino
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
| | - Serena Dato
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
| | - Giuseppina Rose
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Rende, Italy.
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80
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Hauke S, Dutta AK, Eisenbeis VB, Bezold D, Bittner T, Wittwer C, Thakor D, Pavlovic I, Schultz C, Jessen HJ. Photolysis of cell-permeant caged inositol pyrophosphates controls oscillations of cytosolic calcium in a β-cell line. Chem Sci 2019; 10:2687-2692. [PMID: 30996985 PMCID: PMC6419925 DOI: 10.1039/c8sc03479f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 01/09/2019] [Indexed: 12/16/2022] Open
Abstract
β-Cells respond directly to the intracellular photochemical release of caged inositol pyrophosphate isomers with modulations of oscillations in cytosolic Ca2+.
Among many cellular functions, inositol pyrophosphates (PP-InsPs) are metabolic messengers involved in the regulation of glucose uptake, insulin sensitivity, and weight gain. However, their mechanisms of action are still poorly understood. So far, the influence of PP-InsPs on cellular metabolism has been studied by overexpression or knockout/inhibition of relevant metabolizing kinases (IP6Ks, PPIP5Ks). These approaches are, inter alia, limited by time-resolution and potential compensation mechanisms. Here, we describe the synthesis of cell-permeant caged PP-InsPs as tools to rapidly modulate intracellular levels of defined isomers of PP-InsPs in a genetically non-perturbed cellular environment. We show that caged prometabolites readily enter live cells where they are enzymatically converted into still inactive, metabolically stable, photocaged PP-InsPs. Upon light-triggered release of 5-PP-InsP5, the major cellular inositol pyrophosphate, oscillations of intracellular Ca2+ levels in MIN6 cells were transiently reduced to spontaneously recover again. In contrast, uncaging of 1-PP-InsP5, a minor cellular isomer, was without effect. These results provide evidence that PP-InsPs play an active role in regulating [Ca2+]i oscillations, a key element in triggering exocytosis and secretion in β-cells.
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Affiliation(s)
- S Hauke
- EMBL, Heidelberg , 69117 Heidelberg , Germany .
| | - A K Dutta
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - V B Eisenbeis
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - D Bezold
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - T Bittner
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - C Wittwer
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - D Thakor
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - I Pavlovic
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
| | - C Schultz
- EMBL, Heidelberg , 69117 Heidelberg , Germany . .,OHSU , Dept. Physiology & Pharmacology , Portland , OR , USA .
| | - H J Jessen
- University of Freiburg , Institute of Organic Chemistry , 79104 Freiburg , Germany .
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81
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Ezawa T, Saito K. How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism. THE NEW PHYTOLOGIST 2018; 220:1116-1121. [PMID: 29701874 DOI: 10.1111/nph.15187] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 03/22/2018] [Indexed: 05/09/2023]
Abstract
Contents Summary 1116 I. Introduction 1116 II. Foraging for phosphate 1117 III. Fine-tuning of phosphate homeostasis 1117 IV. The frontiers: phosphate translocation and export 1119 V. Conclusions and outlook 1120 Acknowledgements 1120 References 1120 SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism.
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Affiliation(s)
- Tatsuhiro Ezawa
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Katsuharu Saito
- Faculty of Agriculture, Shinshu University, 8304 Minamiminowa, Nagano, 399-4598, Japan
- Research Center for Fungal and Microbial Dynamism, Shinshu University, 8304 Minamiminowa, Nagano, 399-4598, Japan
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82
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Abstract
Inorganic phosphate (Pi) is essential for signal transduction and cell metabolism, and is also an essential structural component of the extracellular matrix of the skeleton. Pi is sensed in bacteria and yeast at the plasma membrane, which activates intracellular signal transduction to control the expression of Pi transporters and other genes that control intracellular Pi levels. In multicellular organisms, Pi homeostasis must be maintained in the organism and at the cellular level, requiring an endocrine and metabolic Pi-sensing mechanism, about which little is currently known. This Review will discuss the metabolic effects of Pi, which are mediated by Pi transporters, inositol pyrophosphates and SYG1-Pho81-XPR1 (SPX)-domain proteins to maintain cellular phosphate homeostasis in the musculoskeletal system. In addition, we will discuss how Pi is sensed by the human body to regulate the production of fibroblast growth factor 23 (FGF23), parathyroid hormone and calcitriol to maintain serum levels of Pi in a narrow range. New findings on the crosstalk between iron and Pi homeostasis in the regulation of FGF23 expression will also be outlined. Mutations in components of these metabolic and endocrine phosphate sensors result in genetic disorders of phosphate homeostasis, cardiomyopathy and familial basal ganglial calcifications, highlighting the importance of this newly emerging area of research.
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Affiliation(s)
- Sampada Chande
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, USA
| | - Clemens Bergwitz
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, USA.
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83
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Kuo HF, Hsu YY, Lin WC, Chen KY, Munnik T, Brearley CA, Chiou TJ. Arabidopsis inositol phosphate kinases IPK1 and ITPK1 constitute a metabolic pathway in maintaining phosphate homeostasis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018. [PMID: 29779236 DOI: 10.1101/270355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/02/2018] [Accepted: 05/09/2018] [Indexed: 05/27/2023]
Abstract
Emerging studies have suggested that there is a close link between inositol phosphate (InsP) metabolism and cellular phosphate (Pi ) homeostasis in eukaryotes; however, whether a common InsP species is deployed as an evolutionarily conserved metabolic messenger to mediate Pi signaling remains unknown. Here, using genetics and InsP profiling combined with Pi -starvation response (PSR) analysis in Arabidopsis thaliana, we showed that the kinase activity of inositol pentakisphosphate 2-kinase (IPK1), an enzyme required for phytate (inositol hexakisphosphate; InsP6 ) synthesis, is indispensable for maintaining Pi homeostasis under Pi -replete conditions, and inositol 1,3,4-trisphosphate 5/6-kinase 1 (ITPK1) plays an equivalent role. Although both ipk1-1 and itpk1 mutants exhibited decreased levels of InsP6 and diphosphoinositol pentakisphosphate (PP-InsP5 ; InsP7 ), disruption of another ITPK family enzyme, ITPK4, which correspondingly caused depletion of InsP6 and InsP7 , did not display similar Pi -related phenotypes, which precludes these InsP species from being effectors. Notably, the level of d/l-Ins(3,4,5,6)P4 was concurrently elevated in both ipk1-1 and itpk1 mutants, which showed a specific correlation with the misregulated Pi phenotypes. However, the level of d/l-Ins(3,4,5,6)P4 is not responsive to Pi starvation that instead manifests a shoot-specific increase in the InsP7 level. This study demonstrates a more nuanced picture of the intersection of InsP metabolism and Pi homeostasis and PSRs than has previously been elaborated, and additionally establishes intermediate steps to phytate biosynthesis in plant vegetative tissues.
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Affiliation(s)
- Hui-Fen Kuo
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Yu-Ying Hsu
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Wei-Chi Lin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Kai-Yu Chen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Teun Munnik
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098XH, The Netherlands
| | - Charles A Brearley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
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84
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Kuo HF, Hsu YY, Lin WC, Chen KY, Munnik T, Brearley CA, Chiou TJ. Arabidopsis inositol phosphate kinases IPK1 and ITPK1 constitute a metabolic pathway in maintaining phosphate homeostasis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 95:613-630. [PMID: 29779236 DOI: 10.1111/tpj.13974] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/02/2018] [Accepted: 05/09/2018] [Indexed: 05/21/2023]
Abstract
Emerging studies have suggested that there is a close link between inositol phosphate (InsP) metabolism and cellular phosphate (Pi ) homeostasis in eukaryotes; however, whether a common InsP species is deployed as an evolutionarily conserved metabolic messenger to mediate Pi signaling remains unknown. Here, using genetics and InsP profiling combined with Pi -starvation response (PSR) analysis in Arabidopsis thaliana, we showed that the kinase activity of inositol pentakisphosphate 2-kinase (IPK1), an enzyme required for phytate (inositol hexakisphosphate; InsP6 ) synthesis, is indispensable for maintaining Pi homeostasis under Pi -replete conditions, and inositol 1,3,4-trisphosphate 5/6-kinase 1 (ITPK1) plays an equivalent role. Although both ipk1-1 and itpk1 mutants exhibited decreased levels of InsP6 and diphosphoinositol pentakisphosphate (PP-InsP5 ; InsP7 ), disruption of another ITPK family enzyme, ITPK4, which correspondingly caused depletion of InsP6 and InsP7 , did not display similar Pi -related phenotypes, which precludes these InsP species from being effectors. Notably, the level of d/l-Ins(3,4,5,6)P4 was concurrently elevated in both ipk1-1 and itpk1 mutants, which showed a specific correlation with the misregulated Pi phenotypes. However, the level of d/l-Ins(3,4,5,6)P4 is not responsive to Pi starvation that instead manifests a shoot-specific increase in the InsP7 level. This study demonstrates a more nuanced picture of the intersection of InsP metabolism and Pi homeostasis and PSRs than has previously been elaborated, and additionally establishes intermediate steps to phytate biosynthesis in plant vegetative tissues.
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Affiliation(s)
- Hui-Fen Kuo
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Yu-Ying Hsu
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Wei-Chi Lin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Kai-Yu Chen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Teun Munnik
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098XH, The Netherlands
| | - Charles A Brearley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
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85
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Wang H, Gu C, Rolfes RJ, Jessen HJ, Shears SB. Structural and biochemical characterization of Siw14: A protein-tyrosine phosphatase fold that metabolizes inositol pyrophosphates. J Biol Chem 2018; 293:6905-6914. [PMID: 29540476 PMCID: PMC5936820 DOI: 10.1074/jbc.ra117.001670] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/26/2018] [Indexed: 01/09/2023] Open
Abstract
Inositol pyrophosphates (PP-InsPs) are "energetic" intracellular signals that are ubiquitous in animals, plants, and fungi; structural and biochemical characterization of PP-InsP metabolic enzymes provides insight into their evolution, reaction mechanisms, and regulation. Here, we describe the 2.35-Å-resolution structure of the catalytic core of Siw14, a 5-PP-InsP phosphatase from Saccharomyces cerevisiae and a member of the protein tyrosine-phosphatase (PTP) superfamily. Conclusions that we derive from structural data are supported by extensive site-directed mutagenesis and kinetic analyses, thereby attributing new functional significance to several key residues. We demonstrate the high activity and exquisite specificity of Siw14 for the 5-diphosphate group of PP-InsPs. The three structural elements that demarcate a 9.2-Å-deep substrate-binding pocket each have spatial equivalents in PTPs, but we identify how these are specialized for Siw14 to bind and hydrolyze the intensely negatively charged PP-InsPs. (a) The catalytic P-loop with the CX5R(S/T) PTP motif contains additional, positively charged residues. (b) A loop between the α5 and α6 helices, corresponding to the Q-loop in PTPs, contains a lysine and an arginine that extend into the catalytic pocket due to displacement of the α5 helix orientation through intramolecular crowding caused by three bulky, hydrophobic residues. (c) The general-acid loop in PTPs is replaced in Siw14 with a flexible loop that does not use an aspartate or glutamate as a general acid. We propose that an acidic residue is not required for phosphoanhydride hydrolysis.
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Affiliation(s)
- Huanchen Wang
- From the Inositol Signaling Group, Signal Transduction Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, , To whom correspondence should be addressed:
Signal Transduction Laboratory, NIEHS, National Institutes of Health, 111 T. W. Alexander Dr., Research Triangle Park, NC 27709. E-mail:
| | - Chunfang Gu
- From the Inositol Signaling Group, Signal Transduction Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Ronda J. Rolfes
- Department of Biology, Georgetown University, Washington, D. C. 20057, and
| | - Henning J. Jessen
- Institute of Organic Chemistry, Albert Ludwigs University, Freiburg, 79104 Freiburg, Germany
| | - Stephen B. Shears
- From the Inositol Signaling Group, Signal Transduction Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
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86
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Wickner RB, Edskes HK, Son M, Bezsonov EE, DeWilde M, Ducatez M. Yeast Prions Compared to Functional Prions and Amyloids. J Mol Biol 2018; 430:3707-3719. [PMID: 29698650 DOI: 10.1016/j.jmb.2018.04.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 01/25/2023]
Abstract
Saccharomyces cerevisiae is an occasional host to an array of prions, most based on self-propagating, self-templating amyloid filaments of a normally soluble protein. [URE3] is a prion of Ure2p, a regulator of nitrogen catabolism, while [PSI+] is a prion of Sup35p, a subunit of the translation termination factor Sup35p. In contrast to the functional prions, [Het-s] of Podospora anserina and [BETA] of yeast, the amyloid-based yeast prions are rare in wild strains, arise sporadically, have an array of prion variants for a single prion protein sequence, have a folded in-register parallel β-sheet amyloid architecture, are detrimental to their hosts, arouse a stress response in the host, and are subject to curing by various host anti-prion systems. These characteristics allow a logical basis for distinction between functional amyloids/prions and prion diseases. These infectious yeast amyloidoses are outstanding models for the many common human amyloid-based diseases that are increasingly found to have some infectious characteristics.
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Affiliation(s)
- Reed B Wickner
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA.
| | - Herman K Edskes
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Moonil Son
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Evgeny E Bezsonov
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Morgan DeWilde
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
| | - Mathieu Ducatez
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda 20892-0830, MD, USA
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87
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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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88
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Lin WY, Lin YY, Chiang SF, Syu C, Hsieh LC, Chiou TJ. Evolution of microRNA827 targeting in the plant kingdom. THE NEW PHYTOLOGIST 2018; 217:1712-1725. [PMID: 29214636 DOI: 10.1111/nph.14938] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/26/2017] [Indexed: 05/08/2023]
Abstract
Unlike most ancient microRNAs, which conservatively target homologous genes across species, microRNA827 (miR827) targets two different types of SPX (SYG1/PHO81/XPR1)-domain-containing genes, NITROGEN LIMITATION ADAPTATION (NLA) and PHOSPHATE TRANSPORTER 5 (PHT5), in Arabidopsis thaliana and Oryza sativa to regulate phosphate (Pi) transport and storage, respectively. However, how miR827 shifted its target preference and its evolutionary history are unknown. Based on target prediction analysis, we found that in most angiosperms, miR827 conservatively targets PHT5 homologs, but in Brassicaceae and Cleomaceae it preferentially targets NLA homologs, and we provide evidence for the transition of target preference during Brassicales evolution. Intriguingly, we found a lineage-specific loss of the miR827-regulatory module in legumes. Analysis of miR827-mediated cleavage efficiency and the expression of PHT5 in A. thaliana indicated that accumulation of mutations in the target site and the exclusion of the target site by alternative transcriptional initiation eliminated PHT5 targeting by miR827. Here, we identified a transition of miR827 target preference during plant evolution and revealed the uniqueness of miR827-mediated regulation among conserved plant miRNAs. Despite the change in its target preference, upregulation of miR827 by Pi starvation and its role in regulating cellular Pi homeostasis were retained.
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Affiliation(s)
- Wei-Yi Lin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
- Department of Agronomy, National Taiwan University, Taipei, 106, Taiwan
| | - Yen-Yu Lin
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Su-Fen Chiang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
| | - Cueihuan Syu
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, 402, Taiwan
| | - Li-Ching Hsieh
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung, 402, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402, Taiwan
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402, Taiwan
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89
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Abstract
Inositol phosphates (IPs) comprise a family of ubiquitous eukaryotic signaling molecules. They have been linked to the regulation of a pleiotropy of important cellular activities, but low abundance and detection difficulties have hampered our understanding. Here we present a method to purify and enrich IPs or other phosphate-rich metabolites from mammalian cells or other sample types. Acid-extracted IPs from cells bind selectively via their phosphate groups to titanium dioxide beads. After washing, the IPs are easily eluted from the beads by increasing the pH. This technique, in combination with downstream analytical methods such as PAGE or SAX-HPLC, opens unprecedented investigative possibilities, allowing appropriate analysis of IPs from virtually any biological or non-biological source.
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Affiliation(s)
- Miranda Sc Wilson
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Adolfo Saiardi
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK
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90
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Gurvich Y, Leshkowitz D, Barkai N. Dual role of starvation signaling in promoting growth and recovery. PLoS Biol 2017; 15:e2002039. [PMID: 29236696 PMCID: PMC5728490 DOI: 10.1371/journal.pbio.2002039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 11/01/2017] [Indexed: 11/19/2022] Open
Abstract
Growing cells are subject to cycles of nutrient depletion and repletion. A shortage of nutrients activates a starvation program that promotes growth in limiting conditions. To examine whether nutrient-deprived cells prepare also for their subsequent recovery, we followed the transcription program activated in budding yeast transferred to low-phosphate media and defined its contribution to cell growth during phosphate limitation and upon recovery. An initial transcription wave was induced by moderate phosphate depletion that did not affect cell growth. A second transcription wave followed when phosphate became growth limiting. The starvation program contributed to growth only in the second, growth-limiting phase. Notably, the early response, activated at moderate depletion, promoted recovery from starvation by increasing phosphate influx upon transfer to rich medium. Our results suggest that cells subject to nutrient depletion prepare not only for growth in the limiting conditions but also for their predicted recovery once nutrients are replenished.
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Affiliation(s)
- Yonat Gurvich
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Dena Leshkowitz
- Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Naama Barkai
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- * E-mail:
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91
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KO of 5-InsP 7 kinase activity transforms the HCT116 colon cancer cell line into a hypermetabolic, growth-inhibited phenotype. Proc Natl Acad Sci U S A 2017; 114:11968-11973. [PMID: 29078269 DOI: 10.1073/pnas.1702370114] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The inositol pyrophosphates 5-InsP7 (diphosphoinositol pentakisphosphate) and 1,5-InsP8 (bis-diphosphoinositol tetrakisphosphate) are highly energetic cellular signals interconverted by the diphosphoinositol pentakisphosphate kinases (PPIP5Ks). Here, we used CRISPR to KO PPIP5Ks in the HCT116 colon cancer cell line. This procedure eliminates 1,5-InsP8 and raises 5-InsP7 levels threefold. Expression of p53 and p21 was up-regulated; proliferation and G1/S cell-cycle transition slowed. Thus, PPIP5Ks are potential targets for tumor therapy. Deletion of the PPIP5Ks elevated [ATP] by 35%; both [ATP] and [5-InsP7] were restored to WT levels by overexpression of PPIP5K1, and a kinase-compromised PPIP5K1 mutant had no effect. This covariance of [ATP] with [5-InsP7] provides direct support for an energy-sensing attribute (i.e., 1 mM Km for ATP) of the 5-InsP7-generating inositol hexakisphosphate kinases (IP6Ks). We consolidate this conclusion by showing that 5-InsP7 levels are elevated on direct delivery of ATP into HCT116 cells using liposomes. Elevated [ATP] in PPIP5K-/- HCT116 cells is underpinned by increased mitochondrial oxidative phosphorylation and enhanced glycolysis. To distinguish between 1,5-InsP8 and 5-InsP7 as drivers of the hypermetabolic and p53-elevated phenotypes, we used IP6K2 RNAi and the pan-IP6K inhibitor, N2-(m-trifluorobenzyl), N6-(p-nitrobenzyl) purine (TNP), to return 5-InsP7 levels in PPIP5K-/- cells to those of WT cells without rescuing 1,5-InsP8 levels. Attenuation of IP6K restored p53 expression but did not affect the hypermetabolic phenotype. Thus, we conclude that 5-InsP7 regulates p53 expression, whereas 1,5-InsP8 regulates ATP levels. These findings attribute hitherto unsuspected functionality for 1,5-InsP8 to bioenergetic homeostasis.
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92
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Puga MI, Rojas-Triana M, de Lorenzo L, Leyva A, Rubio V, Paz-Ares J. Novel signals in the regulation of Pi starvation responses in plants: facts and promises. CURRENT OPINION IN PLANT BIOLOGY 2017; 39:40-49. [PMID: 28587933 DOI: 10.1016/j.pbi.2017.05.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/09/2017] [Accepted: 05/19/2017] [Indexed: 05/10/2023]
Abstract
Plants have evolved numerous adaptive developmental and metabolic responses to cope with growth in conditions of limited phosphate (Pi). Regulation of these Pi starvation responses (PSR) at the organism level involves not only cellular Pi perception in different organs, but also inter-organ communication of Pi levels via systemic signaling. Here we summarize recent discoveries on Pi starvation sensing and signaling, with special emphasis on structure-function studies that showed a role for inositol polyphosphates (InsP) as intracellular Pi signals, and on genomic studies that identified a large number of mRNAs with inter-organ mobility, which provide an immense source of potential systemic signals in the control of PSR and other responses.
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Affiliation(s)
- María Isabel Puga
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain
| | - Mónica Rojas-Triana
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain
| | - Laura de Lorenzo
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA
| | - Antonio Leyva
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain
| | - Vicente Rubio
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain
| | - Javier Paz-Ares
- Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, 28049 Madrid, Spain.
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93
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Saiardi A, Azevedo C, Desfougères Y, Portela-Torres P, Wilson MSC. Microbial inositol polyphosphate metabolic pathway as drug development target. Adv Biol Regul 2017; 67:74-83. [PMID: 28964726 DOI: 10.1016/j.jbior.2017.09.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 12/27/2022]
Abstract
Inositol polyphosphates are a diverse and multifaceted class of intracellular messengers omnipresent in eukaryotic cells. These water-soluble molecules regulate many aspects of fundamental cell physiology. Removing this metabolic pathway is deleterious: inositol phosphate kinase null mutations can result in lethality or substantial growth phenotypes. Inositol polyphosphate synthesis occurs through the actions of a set of kinases that phosphorylate phospholipase-generated IP3 to higher phosphorylated forms, such as the fully phosphorylated IP6 and the inositol pyrophosphates IP7 and IP8. Unicellular organisms have a reduced array of the kinases for synthesis of higher phosphorylated inositol polyphosphates, while human cells possess two metabolic routes to IP6. The enzymes responsible for inositol polyphosphate synthesis have been identified in all eukaryote genomes, although their amino acid sequence homology is often barely detectable by common search algorithms. Homology between human and microbial inositol phosphate kinases is restricted to a few catalytically important residues. Recent studies of the inositol phosphate metabolic pathways in pathogenic fungi (Cryptococcus neoformans) and protozoa (Trypanosome brucei) have revealed the importance of the highly phosphorylated inositol polyphosphates to the fitness and thus virulence of these pathogens. Given this, identification of inositol kinase inhibitors specifically targeting the kinases of pathogenic microorganisms is desirable and achievable.
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Affiliation(s)
- Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK.
| | - Cristina Azevedo
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Yann Desfougères
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Paloma Portela-Torres
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Miranda S C Wilson
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, UK
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94
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Cordeiro CD, Saiardi A, Docampo R. The inositol pyrophosphate synthesis pathway in Trypanosoma brucei is linked to polyphosphate synthesis in acidocalcisomes. Mol Microbiol 2017; 106:319-333. [PMID: 28792096 DOI: 10.1111/mmi.13766] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2017] [Indexed: 12/19/2022]
Abstract
Inositol pyrophosphates are novel signaling molecules possessing high-energy pyrophosphate bonds and involved in a number of biological functions. Here, we report the correct identification and characterization of the kinases involved in the inositol pyrophosphate biosynthetic pathway in Trypanosoma brucei: inositol polyphosphate multikinase (TbIPMK), inositol pentakisphosphate 2-kinase (TbIP5K) and inositol hexakisphosphate kinase (TbIP6K). TbIP5K and TbIP6K were not identifiable by sequence alone and their activities were validated by enzymatic assays with the recombinant proteins or by their complementation of yeast mutants. We also analyzed T. brucei extracts for the presence of inositol phosphates using polyacrylamide gel electrophoresis and high-performance liquid chromatography. Interestingly, we could detect inositol phosphate (IP), inositol 4,5-bisphosphate (IP2 ), inositol 1,4,5-trisphosphate (IP3 ), and inositol hexakisphosphate (IP6 ) in T. brucei different stages. Bloodstream forms unable to produce inositol pyrophosphates, due to downregulation of TbIPMK expression by conditional knockout, have reduced levels of polyphosphate and altered acidocalcisomes. Our study links the inositol pyrophosphate pathway to the synthesis of polyphosphate in acidocalcisomes, and may lead to better understanding of these organisms and provide new targets for drug discovery.
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Affiliation(s)
- Ciro D Cordeiro
- Department of Cellular Biology, and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, WC1E 6BT, Gower Street, London, UK
| | - Roberto Docampo
- Department of Cellular Biology, and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
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95
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PhoU Allows Rapid Adaptation to High Phosphate Concentrations by Modulating PstSCAB Transport Rate in Sinorhizobium meliloti. J Bacteriol 2017; 199:JB.00143-17. [PMID: 28416708 DOI: 10.1128/jb.00143-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 04/11/2017] [Indexed: 01/14/2023] Open
Abstract
Maintenance of cellular phosphate homeostasis is essential for cellular life. The PhoU protein has emerged as a key regulator of this process in bacteria, and it is suggested to modulate phosphate import by PstSCAB and control activation of the phosphate limitation response by the PhoR-PhoB two-component system. However, a proper understanding of PhoU has remained elusive due to numerous complications of mutating phoU, including loss of viability and the genetic instability of the mutants. Here, we developed two sets of strains of Sinorhizobium meliloti that overcame these limitations and allowed a more detailed and comprehensive analysis of the biological and molecular activities of PhoU. The data showed that phoU cannot be deleted in the presence of phosphate unless PstSCAB is inactivated also. However, phoU deletions were readily recovered in phosphate-free media, and characterization of these mutants revealed that addition of phosphate to the environment resulted in toxic levels of PstSCAB-mediated phosphate accumulation. Phosphate uptake experiments indicated that PhoU significantly decreased the PstSCAB transport rate specifically in phosphate-replete cells but not in phosphate-starved cells and that PhoU could rapidly respond to elevated environmental phosphate concentrations and decrease the PstSCAB transport rate. Site-directed mutagenesis results suggested that the ability of PhoU to respond to phosphate levels was independent of the conformation of the PstSCAB transporter. Additionally, PhoU-PhoU and PhoU-PhoR interactions were detected using a bacterial two-hybrid screen. We propose that PhoU modulates PstSCAB and PhoR-PhoB in response to local, internal fluctuations in phosphate concentrations resulting from PstSCAB-mediated phosphate import.IMPORTANCE Correct maintenance of cellular phosphate homeostasis is critical in all kingdoms of life and in bacteria involves the PhoU protein. This work provides novel insights into the role of the Sinorhizobium meliloti PhoU protein, which plays a key role in rapid adaptation to elevated phosphate concentrations. It is shown that PhoU rapidly responds to elevated phosphate levels by significantly decreasing the phosphate transport of PstSCAB, thereby preventing phosphate toxicity and cell death. Additionally, a new model for phosphate sensing in bacterial species which involves the PhoR-PhoB two-component system is presented. This work provides new insights into the bacterial response to changing environmental conditions and into regulation of the phosphate limitation response that influences numerous bacterial processes, including antibiotic production and virulence.
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96
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Shears SB. Intimate connections: Inositol pyrophosphates at the interface of metabolic regulation and cell signaling. J Cell Physiol 2017; 233:1897-1912. [PMID: 28542902 DOI: 10.1002/jcp.26017] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 05/18/2017] [Indexed: 12/11/2022]
Abstract
Inositol pyrophosphates are small, diffusible signaling molecules that possess the most concentrated three-dimensional array of phosphate groups in Nature; up to eight phosphates are crammed around a six-carbon inositol ring. This review discusses the physico-chemical properties of these unique molecules, and their mechanisms of action. Also provided is information on the enzymes that regulate the levels and hence the signaling properties of these molecules. This review pursues the idea that many of the biological effects of inositol pyrophosphates can be rationalized by their actions at the interface of cell signaling and metabolism that is essential to cellular and organismal homeostasis.
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Affiliation(s)
- Stephen B Shears
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
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97
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Has Inositol Played Any Role in the Origin of Life? Life (Basel) 2017; 7:life7020024. [PMID: 28587245 PMCID: PMC5492146 DOI: 10.3390/life7020024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/26/2017] [Accepted: 06/02/2017] [Indexed: 12/11/2022] Open
Abstract
Phosphorus, as phosphate, plays a paramount role in biology. Since phosphate transfer reactions are an integral part of contemporary life, phosphate may have been incorporated into the initial molecules at the very beginning. To facilitate the studies into early phosphate utilization, we should look retrospectively to phosphate-rich molecules present in today’s cells. Overlooked by origin of life studies until now, inositol and the inositol phosphates, of which some species possess more phosphate groups that carbon atoms, represent ideal molecules to consider in this context. The current sophisticated association of inositol with phosphate, and the roles that some inositol phosphates play in regulating cellular phosphate homeostasis, intriguingly suggest that inositol might have played some role in the prebiotic process of phosphate exploitation. Inositol can be synthesized abiotically and, unlike glucose or ribose, is chemically stable. This stability makes inositol the ideal candidate for the earliest organophosphate molecules, as primitive inositol phosphates. I also present arguments suggesting roles for some inositol phosphates in early chemical evolution events. Finally, the possible prebiotic synthesis of inositol pyrophosphates could have generated high-energy molecules to be utilized in primitive trans-phosphorylating processes.
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98
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Gu C, Nguyen HN, Hofer A, Jessen HJ, Dai X, Wang H, Shears SB. The Significance of the Bifunctional Kinase/Phosphatase Activities of Diphosphoinositol Pentakisphosphate Kinases (PPIP5Ks) for Coupling Inositol Pyrophosphate Cell Signaling to Cellular Phosphate Homeostasis. J Biol Chem 2017; 292:4544-4555. [PMID: 28126903 PMCID: PMC5377771 DOI: 10.1074/jbc.m116.765743] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/25/2017] [Indexed: 12/31/2022] Open
Abstract
Proteins responsible for Pi homeostasis are critical for all life. In Saccharomyces cerevisiae, extracellular [Pi] is "sensed" by the inositol-hexakisphosphate kinase (IP6K) that synthesizes the intracellular inositol pyrophosphate 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) as follows: during a period of Pi starvation, there is a decline in cellular [ATP]; the unusually low affinity of IP6Ks for ATP compels 5-InsP7 levels to fall in parallel (Azevedo, C., and Saiardi, A. (2017) Trends. Biochem. Sci. 42, 219-231. Hitherto, such Pi sensing has not been documented in metazoans. Here, using a human intestinal epithelial cell line (HCT116), we show that levels of both 5-InsP7 and ATP decrease upon [Pi] starvation and subsequently recover during Pi replenishment. However, a separate inositol pyrophosphate, 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8), reacts more dramatically (i.e. with a wider dynamic range and greater sensitivity). To understand this novel InsP8 response, we characterized kinetic properties of the bifunctional 5-InsP7 kinase/InsP8 phosphatase activities of full-length diphosphoinositol pentakisphosphate kinases (PPIP5Ks). These data fulfil previously published criteria for any bifunctional kinase/phosphatase to exhibit concentration robustness, permitting levels of the kinase product (InsP8 in this case) to fluctuate independently of varying precursor (i.e. 5-InsP7) pool size. Moreover, we report that InsP8 phosphatase activities of PPIP5Ks are strongly inhibited by Pi (40-90% within the 0-1 mm range). For PPIP5K2, Pi sensing by InsP8 is amplified by a 2-fold activation of 5-InsP7 kinase activity by Pi within the 0-5 mm range. Overall, our data reveal mechanisms that can contribute to specificity in inositol pyrophosphate signaling, regulating InsP8 turnover independently of 5-InsP7, in response to fluctuations in extracellular supply of a key nutrient.
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Affiliation(s)
- Chunfang Gu
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Hoai-Nghia Nguyen
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Alexandre Hofer
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Henning J Jessen
- Institute of Organic Chemistry, Albert Ludwigs University, Albertstrasse 21, 79104 Freiburg, Germany, and
| | - Xuming Dai
- Division of Cardiology, McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Huanchen Wang
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709
| | - Stephen B Shears
- From the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, 27709,
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