1
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Vandermeulen MD, Lorenz MC, Cullen PJ. Conserved signaling modules regulate filamentous growth in fungi: a model for eukaryotic cell differentiation. Genetics 2024:iyae122. [PMID: 39239926 DOI: 10.1093/genetics/iyae122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 07/20/2024] [Indexed: 09/07/2024] Open
Abstract
Eukaryotic organisms are composed of different cell types with defined shapes and functions. Specific cell types are produced by the process of cell differentiation, which is regulated by signal transduction pathways. Signaling pathways regulate cell differentiation by sensing cues and controlling the expression of target genes whose products generate cell types with specific attributes. In studying how cells differentiate, fungi have proved valuable models because of their ease of genetic manipulation and striking cell morphologies. Many fungal species undergo filamentous growth-a specialized growth pattern where cells produce elongated tube-like projections. Filamentous growth promotes expansion into new environments, including invasion into plant and animal hosts by fungal pathogens. The same signaling pathways that regulate filamentous growth in fungi also control cell differentiation throughout eukaryotes and include highly conserved mitogen-activated protein kinase (MAPK) pathways, which is the focus of this review. In many fungal species, mucin-type sensors regulate MAPK pathways to control filamentous growth in response to diverse stimuli. Once activated, MAPK pathways reorganize cell polarity, induce changes in cell adhesion, and promote the secretion of degradative enzymes that mediate access to new environments. However, MAPK pathway regulation is complicated because related pathways can share components with each other yet induce unique responses (i.e. signal specificity). In addition, MAPK pathways function in highly integrated networks with other regulatory pathways (i.e. signal integration). Here, we discuss signal specificity and integration in several yeast models (mainly Saccharomyces cerevisiae and Candida albicans) by focusing on the filamentation MAPK pathway. Because of the strong evolutionary ties between species, a deeper understanding of the regulation of filamentous growth in established models and increasingly diverse fungal species can reveal fundamentally new mechanisms underlying eukaryotic cell differentiation.
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Affiliation(s)
| | - Michael C Lorenz
- Department of Microbiology and Molecular Genetics, University of Texas McGovern Medical School, Houston, TX 77030, USA
| | - Paul J Cullen
- Department of Biological Sciences, University at Buffalo, Buffalo, NY 14260-1300, USA
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2
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Huang Y, Klionsky DJ. Pho81 is a novel regulator of pexophagy induced by phosphate starvation. Autophagy 2024:1-2. [PMID: 38991544 DOI: 10.1080/15548627.2024.2377421] [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: 07/13/2024] Open
Abstract
In the budding yeast Saccharomyces cerevisiae, macroautophagy/autophagy can be induced by various types of starvation. It is thought that potential autophagic substrates vary to meet specific nutritional demands under different starvation conditions. In a recent study, Gross et al. found that autophagy induced by phosphate starvation includes many selective aspects. For example, this work identified Pho81 as a regulator of pexophagy under conditions of phosphate starvation. Pho81 senses phosphate metabolites and directly interacts with Atg11 to promote Atg1-mediated Atg11 phosphorylation. This finding provides an example of how modulation of the Atg1/ULK kinase complex can convey specific metabolic information to regulate autophagic substrates.Abbreviation: AKC: Atg1/ULK kinase complex.
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Affiliation(s)
- Yuxiang Huang
- Life Sciences Institute and Department of Molecular, Cellular and Development Biology, University of Michigan, Ann Arbor, MI, USA
| | - Daniel J Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Development Biology, University of Michigan, Ann Arbor, MI, USA
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3
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Haykir B, Moser SO, Pastor-Arroyo EM, Schnitzbauer U, Radvanyi Z, Prucker I, Qiu D, Fiedler D, Saiardi A, Jessen HJ, Hernando N, Wagner CA. The Ip6k1 and Ip6k2 Kinases Are Critical for Normal Renal Tubular Function. J Am Soc Nephrol 2024; 35:441-455. [PMID: 38317282 PMCID: PMC11000740 DOI: 10.1681/asn.0000000000000303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 12/24/2023] [Indexed: 02/07/2024] Open
Abstract
SIGNIFICANCE STATEMENT Kidneys are gatekeepers of systemic inorganic phosphate balance because they control urinary phosphate excretion. In yeast and plants, inositol hexakisphosphate kinases (IP6Ks) are central to regulate phosphate metabolism, whereas their role in mammalian phosphate homeostasis is mostly unknown. We demonstrate in a renal cell line and in mice that Ip6k1 and Ip6k2 are critical for normal expression and function of the major renal Na + /Pi transporters NaPi-IIa and NaPi-IIc. Moreover, Ip6k1/2-/- mice also show symptoms of more generalized kidney dysfunction. Thus, our results suggest that IP6Ks are essential for phosphate metabolism and proper kidney function in mammals. BACKGROUND Inorganic phosphate is an essential mineral, and its plasma levels are tightly regulated. In mammals, kidneys are critical for maintaining phosphate homeostasis through mechanisms that ultimately regulate the expression of the Na + /Pi cotransporters NaPi-IIa and NaPi-IIc in proximal tubules. Inositol pyrophosphate 5-IP 7 , generated by IP6Ks, is a main regulator of phosphate metabolism in yeast and plants. IP6Ks are conserved in mammals, but their role in phosphate metabolism in vivo remains unexplored. METHODS We used in vitro (opossum kidney cells) and in vivo (renal tubular-specific Ip6k1/2-/- mice) models to analyze the role of IP6K1/2 in phosphate homeostasis in mammals. RESULTS In both systems, Ip6k1 and Ip6k2 are responsible for synthesis of 5-IP 7 . Depletion of Ip6k1/2 in vitro reduced phosphate transport and mRNA expression of Na + /Pi cotransporters, and it blunts phosphate transport adaptation to changes in ambient phosphate. Renal ablation of both kinases in mice also downregulates the expression of NaPi-IIa and NaPi-IIc and lowered the uptake of phosphate into proximal renal brush border membranes. In addition, the absence of Ip6k1 and Ip6k2 reduced the plasma concentration of fibroblast growth factor 23 and increased bone resorption, despite of which homozygous males develop hypophosphatemia. Ip6k1/2-/- mice also show increased diuresis, albuminuria, and hypercalciuria, although the morphology of glomeruli and proximal brush border membrane seemed unaffected. CONCLUSIONS Depletion of renal Ip6k1/2 in mice not only altered phosphate homeostasis but also dysregulated other kidney functions.
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Affiliation(s)
- Betül Haykir
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Seraina Olivia Moser
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Eva Maria Pastor-Arroyo
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Udo Schnitzbauer
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Zsuzsa Radvanyi
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Isabel Prucker
- The Center for Integrative Biological Signalling Studies, Institute of Organic Chemistry and CIBSS, University of Freiburg, Freiburg, Germany
| | - Danye Qiu
- The Center for Integrative Biological Signalling Studies, Institute of Organic Chemistry and CIBSS, University of Freiburg, Freiburg, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Henning J. Jessen
- The Center for Integrative Biological Signalling Studies, Institute of Organic Chemistry and CIBSS, University of Freiburg, Freiburg, Germany
| | - Nati Hernando
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
| | - Carsten A. Wagner
- Switzerland and National Center of Competence in Research NCCR Kidney.CH, Institute of Physiology, University of Zurich, Zürich, Switzerland
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4
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Mihiret YE, Schaaf G, Kamleitner M. Protein pyrophosphorylation by inositol phosphates: a novel post-translational modification in plants? FRONTIERS IN PLANT SCIENCE 2024; 15:1347922. [PMID: 38455731 PMCID: PMC10917965 DOI: 10.3389/fpls.2024.1347922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/01/2024] [Indexed: 03/09/2024]
Abstract
Inositol pyrophosphates (PP-InsPs) are energy-rich molecules harboring one or more diphosphate moieties. PP-InsPs are found in all eukaryotes evaluated and their functional versatility is reflected in the various cellular events in which they take part. These include, among others, insulin signaling and intracellular trafficking in mammals, as well as innate immunity and hormone and phosphate signaling in plants. The molecular mechanisms by which PP-InsPs exert such functions are proposed to rely on the allosteric regulation via direct binding to proteins, by competing with other ligands, or by protein pyrophosphorylation. The latter is the focus of this review, where we outline a historical perspective surrounding the first findings, almost 20 years ago, that certain proteins can be phosphorylated by PP-InsPs in vitro. Strikingly, in vitro phosphorylation occurs by an apparent enzyme-independent but Mg2+-dependent transfer of the β-phosphoryl group of an inositol pyrophosphate to an already phosphorylated serine residue at Glu/Asp-rich protein regions. Ribosome biogenesis, vesicle trafficking and transcription are among the cellular events suggested to be modulated by protein pyrophosphorylation in yeast and mammals. Here we discuss the latest efforts in identifying targets of protein pyrophosphorylation, pointing out the methodological challenges that have hindered the full understanding of this unique post-translational modification, and focusing on the latest advances in mass spectrometry that finally provided convincing evidence that PP-InsP-mediated pyrophosphorylation also occurs in vivo. We also speculate about the relevance of this post-translational modification in plants in a discussion centered around the protein kinase CK2, whose activity is critical for pyrophosphorylation of animal and yeast proteins. This enzyme is widely present in plant species and several of its functions overlap with those of PP-InsPs. Until now, there is virtually no data on pyrophosphorylation of plant proteins, which is an exciting field that remains to be explored.
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Affiliation(s)
| | | | - Marília Kamleitner
- Department of Plant Nutrition, Institute of Crop Science and Resource Conservation, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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5
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Qi J, Shi L, Zhu L, Chen Y, Zhu H, Cheng W, Chen AF, Fu C. Functions, Mechanisms, and therapeutic applications of the inositol pyrophosphates 5PP-InsP 5 and InsP 8 in mammalian cells. J Cardiovasc Transl Res 2024; 17:197-215. [PMID: 37615888 DOI: 10.1007/s12265-023-10427-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 08/14/2023] [Indexed: 08/25/2023]
Abstract
Water-soluble myo-inositol phosphates have long been characterized as second messengers. The signaling properties of these compounds are determined by the number and arrangement of phosphate groups on the myo-inositol backbone. Recently, higher inositol phosphates with pyrophosphate groups were recognized as signaling molecules. 5-Diphosphoinositol 1,2,3,4,6-pentakisphosphate (5PP-InsP5) is the most abundant isoform, constituting more than 90% of intracellular inositol pyrophosphates. 5PP-InsP5 can be further phosphorylated to 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8). These two molecules, 5PP-InsP5 and InsP8, are present in various subcellular compartments, where they participate in regulating diverse cellular processes such as cell death, energy homeostasis, and cytoskeletal dynamics. The synthesis and metabolism of inositol pyrophosphates are subjected to tight regulation, allowing for their highly specific functions. Blocking the 5PP-InsP5/InsP8 signaling pathway by inhibiting the biosynthesis of 5PP-InsP5 demonstrates therapeutic benefits in preclinical studies, and thus holds promise as a therapeutic approach for certain diseases treatment, such as metabolic disorders.
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Affiliation(s)
- Ji Qi
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Linhui Shi
- Department of Critical Care Unit, Ningbo Medical Center Li Huili Hospital, Ningbo University, Ningbo, 315040, Zhejiang, China
| | - Limei Zhu
- Department of Trauma Orthopedics, Ningbo No.6 Hospital, Ningbo, 315040, China
| | - Yuanyuan Chen
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Hong Zhu
- Department of Obstetrics and Gynecology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Weiwei Cheng
- Department of Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Alex F Chen
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
| | - Chenglai Fu
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
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6
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Gogianu LI, Ruta LL, Farcasanu IC. Kcs1 and Vip1: The Key Enzymes behind Inositol Pyrophosphate Signaling in Saccharomyces cerevisiae. Biomolecules 2024; 14:152. [PMID: 38397389 PMCID: PMC10886477 DOI: 10.3390/biom14020152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/19/2024] [Accepted: 01/25/2024] [Indexed: 02/25/2024] Open
Abstract
The inositol pyrophosphate pathway, a complex cell signaling network, plays a pivotal role in orchestrating vital cellular processes in the budding yeast, where it regulates cell cycle progression, growth, endocytosis, exocytosis, apoptosis, telomere elongation, ribosome biogenesis, and stress responses. This pathway has gained significant attention in pharmacology and medicine due to its role in generating inositol pyrophosphates, which serve as crucial signaling molecules not only in yeast, but also in higher eukaryotes. As targets for therapeutic development, genetic modifications within this pathway hold promise for disease treatment strategies, offering practical applications in biotechnology. The model organism Saccharomyces cerevisiae, renowned for its genetic tractability, has been instrumental in various studies related to the inositol pyrophosphate pathway. This review is focused on the Kcs1 and Vip1, the two enzymes involved in the biosynthesis of inositol pyrophosphate in S. cerevisiae, highlighting their roles in various cell processes, and providing an up-to-date overview of their relationship with phosphate homeostasis. Moreover, the review underscores the potential applications of these findings in the realms of medicine and biotechnology, highlighting the profound implications of comprehending this intricate signaling network.
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Affiliation(s)
- Larisa Ioana Gogianu
- Doctoral School of Biology, Faculty of Biology, University of Bucharest, Splaiul Independenței 91-95, 050095 Bucharest, Romania;
- National Institute for Research and Development in Microtechnologies, Erou Iancu Nicolae Str. 126A, 077190 Voluntari, Romania
| | - Lavinia Liliana Ruta
- Faculty of Chemistry, University of Bucharest, Panduri Road 90-92, 050663 Bucharest, Romania;
| | - Ileana Cornelia Farcasanu
- Doctoral School of Biology, Faculty of Biology, University of Bucharest, Splaiul Independenței 91-95, 050095 Bucharest, Romania;
- Faculty of Chemistry, University of Bucharest, Panduri Road 90-92, 050663 Bucharest, Romania;
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7
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Gu C, Li X, Zong G, Wang H, Shears SB. IP8: A quantitatively minor inositol pyrophosphate signaling molecule that punches above its weight. Adv Biol Regul 2024; 91:101002. [PMID: 38064879 DOI: 10.1016/j.jbior.2023.101002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 11/27/2023] [Indexed: 02/25/2024]
Abstract
The inositol pyrophosphates (PP-IPs) are specialized members of the wider inositol phosphate signaling family that possess functionally significant diphosphate groups. The PP-IPs exhibit remarkable functionally versatility throughout the eukaryotic kingdoms. However, a quantitatively minor PP-IP - 1,5 bisdiphosphoinositol tetrakisphosphate (1,5-IP8) - has received considerably less attention from the cell signalling community. The main purpose of this review is to summarize recently-published data which have now brought 1,5-IP8 into the spotlight, by expanding insight into the molecular mechanisms by which this polyphosphate regulates many fundamental biological processes.
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Affiliation(s)
- Chunfang Gu
- Inositol signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 USA
| | - Xingyao Li
- Inositol signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 USA
| | - Guangning Zong
- Inositol signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 USA
| | - Huanchen Wang
- Inositol signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 USA.
| | - Stephen B Shears
- Inositol signaling Group, Signal Transduction Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 USA.
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8
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Takado M, Komamura T, Nishimura T, Ohkubo I, Ohuchi K, Matsumoto T, Takeda K. Phosphate uptake restriction, phosphate export, and polyphosphate synthesis contribute synergistically to cellular proliferation and survival. J Biol Chem 2023; 299:105454. [PMID: 37949217 PMCID: PMC10704438 DOI: 10.1016/j.jbc.2023.105454] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 10/22/2023] [Accepted: 10/25/2023] [Indexed: 11/12/2023] Open
Abstract
Phosphate (Pi) is a macronutrient, and Pi homeostasis is essential for life. Pi homeostasis has been intensively studied; however, many questions remain, even at the cellular level. Using Schizosaccharomyces pombe, we sought to better understand cellular Pi homeostasis and showed that three Pi regulators with SPX domains, Xpr1/Spx2, Pqr1, and the VTC complex synergistically contribute to Pi homeostasis to support cell proliferation and survival. SPX domains bind to inositol pyrophosphate and modulate activities of Pi-related proteins. Xpr1 is a plasma membrane protein and its Pi-exporting activity has been demonstrated in metazoan orthologs, but not in fungi. We first found that S. pombe Xpr1 is a Pi exporter, activity of which is regulated and accelerated in the mutants of Pqr1 and the VTC complex. Pqr1 is the ubiquitin ligase downregulating the Pi importers, Pho84 and Pho842. The VTC complex synthesizes polyphosphate in vacuoles. Triple deletion of Xpr1, Pqr1, and Vtc4, the catalytic core of the VTC complex, was nearly lethal in normal medium but survivable at lower [Pi]. All double-deletion mutants of the three genes were viable at normal Pi, but Δpqr1Δxpr1 showed severe viability loss at high [Pi], accompanied by hyper-elevation of cellular total Pi and free Pi. This study suggests that the three cellular processes, restriction of Pi uptake, Pi export, and polyP synthesis, contribute synergistically to cell proliferation through maintenance of Pi homeostasis, leading to the hypothesis that cooperation between Pqr1, Xpr1, and the VTC complex protects the cytoplasm and/or the nucleus from lethal elevation of free Pi.
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Affiliation(s)
- Masahiro Takado
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Tochi Komamura
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Tomoki Nishimura
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Ikkei Ohkubo
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Keita Ohuchi
- Graduate School of Natural Science, Konan University, Kobe, Japan
| | - Tomohiro Matsumoto
- Radiation Biology Center, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kojiro Takeda
- Graduate School of Natural Science, Konan University, Kobe, Japan; Institute of Integrative Neurobiology, Konan University, Kobe, Japan.
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9
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Chabert V, Kim GD, Qiu D, Liu G, Michaillat Mayer L, Jamsheer K M, Jessen HJ, Mayer A. Inositol pyrophosphate dynamics reveals control of the yeast phosphate starvation program through 1,5-IP 8 and the SPX domain of Pho81. eLife 2023; 12:RP87956. [PMID: 37728314 PMCID: PMC10511240 DOI: 10.7554/elife.87956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023] Open
Abstract
Eukaryotic cells control inorganic phosphate to balance its role as essential macronutrient with its negative bioenergetic impact on reactions liberating phosphate. Phosphate homeostasis depends on the conserved INPHORS signaling pathway that utilizes inositol pyrophosphates and SPX receptor domains. Since cells synthesize various inositol pyrophosphates and SPX domains bind them promiscuously, it is unclear whether a specific inositol pyrophosphate regulates SPX domains in vivo, or whether multiple inositol pyrophosphates act as a pool. In contrast to previous models, which postulated that phosphate starvation is signaled by increased production of the inositol pyrophosphate 1-IP7, we now show that the levels of all detectable inositol pyrophosphates of yeast, 1-IP7, 5-IP7, and 1,5-IP8, strongly decline upon phosphate starvation. Among these, specifically the decline of 1,5-IP8 triggers the transcriptional phosphate starvation response, the PHO pathway. 1,5-IP8 inactivates the cyclin-dependent kinase inhibitor Pho81 through its SPX domain. This stimulates the cyclin-dependent kinase Pho85-Pho80 to phosphorylate the transcription factor Pho4 and repress the PHO pathway. Combining our results with observations from other systems, we propose a unified model where 1,5-IP8 signals cytosolic phosphate abundance to SPX proteins in fungi, plants, and mammals. Its absence triggers starvation responses.
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Affiliation(s)
- Valentin Chabert
- Département d'immunobiologie, Université de LausanneEpalingesSwitzerland
| | - Geun-Don Kim
- Département d'immunobiologie, Université de LausanneEpalingesSwitzerland
| | - Danye Qiu
- Institute of Organic Chemistry, Centre for Integrative Biological Signalling Studies, University of FreiburgFreiburgGermany
| | - Guizhen Liu
- Institute of Organic Chemistry, Centre for Integrative Biological Signalling Studies, University of FreiburgFreiburgGermany
| | | | | | - Henning J Jessen
- Institute of Organic Chemistry, Centre for Integrative Biological Signalling Studies, University of FreiburgFreiburgGermany
| | - Andreas Mayer
- Département d'immunobiologie, Université de LausanneEpalingesSwitzerland
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10
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Kanemaru K, Nakamura Y. Activation Mechanisms and Diverse Functions of Mammalian Phospholipase C. Biomolecules 2023; 13:915. [PMID: 37371495 DOI: 10.3390/biom13060915] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
Phospholipase C (PLC) plays pivotal roles in regulating various cellular functions by metabolizing phosphatidylinositol 4,5-bisphosphate in the plasma membrane. This process generates two second messengers, inositol 1,4,5-trisphosphate and diacylglycerol, which respectively regulate the intracellular Ca2+ levels and protein kinase C activation. In mammals, six classes of typical PLC have been identified and classified based on their structure and activation mechanisms. They all share X and Y domains, which are responsible for enzymatic activity, as well as subtype-specific domains. Furthermore, in addition to typical PLC, atypical PLC with unique structures solely harboring an X domain has been recently discovered. Collectively, seven classes and 16 isozymes of mammalian PLC are known to date. Dysregulation of PLC activity has been implicated in several pathophysiological conditions, including cancer, cardiovascular diseases, and neurological disorders. Therefore, identification of new drug targets that can selectively modulate PLC activity is important. The present review focuses on the structures, activation mechanisms, and physiological functions of mammalian PLC.
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Affiliation(s)
- Kaori Kanemaru
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba 278-8510, Japan
| | - Yoshikazu Nakamura
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Chiba 278-8510, Japan
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11
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Tian J, Pu M, Chen B, Wang G, Li C, Zhang X, Yu Y, Wang Z, Kong Z. Verticillium dahliae Asp1 regulates the transition from vegetative growth to asexual reproduction by modulating microtubule dynamic organization. Environ Microbiol 2023; 25:738-750. [PMID: 36537236 DOI: 10.1111/1462-2920.16320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
Verticillium dahliae is a devastating pathogenic fungus that causes severe vascular wilts in more than 400 dicotyledonous plants. The conidiation of V. dahliae in plant vascular tissues is the key strategy for its adaptation to the nutrient-poor environment and is required for its pathogenicity. However, it remains unclear about the regulatory mechanism of conidium production of V. dahliae in vascular tissues. Here, we found that VdAsp1, encoding an inositol polyphosphate kinase, is indispensable for the pathogenicity of V. dahliae. Loss of VdAsp1 function does not affect the invasion of the host, but it impairs the colonization and proliferation in vascular tissues. The ΔVdAsp1 mutant shows defective initiation of conidiophore formation and reduced expression of genes associated with the central developmental pathway. By live-cell imaging, we observed that some of ΔVdAsp1 mutant hyphae are swollen, and microtubule arrangements at the apical region of these hyphae are disorganized. These results indicate that VdAsp1 regulates the transition from vegetative growth to asexual reproduction by modulating microtubule dynamic organization, which is essential for V. dahliae to colonize and proliferate in vascular tissues. These findings provided a potential new direction in the control of vascular wilt pathogen by targeting conidium production in vascular tissues.
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Affiliation(s)
- Juan Tian
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Mengli Pu
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Bin Chen
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Guangda Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chunli Li
- Public Technology Service Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaxia Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yanjun Yu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhi Wang
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, Academy of Agronomy, Shanxi Agricultural University, Taiyuan, China
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12
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Deprez MA, Caligaris M, Rosseels J, Hatakeyama R, Ghillebert R, Sampaio-Marques B, Mudholkar K, Eskes E, Meert E, Ungermann C, Ludovico P, Rospert S, De Virgilio C, Winderickx J. The nutrient-responsive CDK Pho85 primes the Sch9 kinase for its activation by TORC1. PLoS Genet 2023; 19:e1010641. [PMID: 36791155 PMCID: PMC9974134 DOI: 10.1371/journal.pgen.1010641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 02/28/2023] [Accepted: 01/27/2023] [Indexed: 02/16/2023] Open
Abstract
Yeast cells maintain an intricate network of nutrient signaling pathways enabling them to integrate information on the availability of different nutrients and adjust their metabolism and growth accordingly. Cells that are no longer capable of integrating this information, or that are unable to make the necessary adaptations, will cease growth and eventually die. Here, we studied the molecular basis underlying the synthetic lethality caused by loss of the protein kinase Sch9, a key player in amino acid signaling and proximal effector of the conserved growth-regulatory TORC1 complex, when combined with either loss of the cyclin-dependent kinase (CDK) Pho85 or loss of its inhibitor Pho81, which both have pivotal roles in phosphate sensing and cell cycle regulation. We demonstrate that it is specifically the CDK-cyclin pair Pho85-Pho80 or the partially redundant CDK-cyclin pairs Pho85-Pcl6/Pcl7 that become essential for growth when Sch9 is absent. Interestingly, the respective three CDK-cyclin pairs regulate the activity and distribution of the phosphatidylinositol-3 phosphate 5-kinase Fab1 on endosomes and vacuoles, where it generates phosphatidylinositol-3,5 bisphosphate that serves to recruit both TORC1 and its substrate Sch9. In addition, Pho85-Pho80 directly phosphorylates Sch9 at Ser726, and to a lesser extent at Thr723, thereby priming Sch9 for its subsequent phosphorylation and activation by TORC1. The TORC1-Sch9 signaling branch therefore integrates Pho85-mediated information at different levels. In this context, we also discovered that loss of the transcription factor Pho4 rescued the synthetic lethality caused by loss of Pho85 and Sch9, indicating that both signaling pathways also converge on Pho4, which appears to be wired to a feedback loop involving the high-affinity phosphate transporter Pho84 that fine-tunes Sch9-mediated responses.
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Affiliation(s)
- Marie-Anne Deprez
- Department of Biology, Functional Biology, KU Leuven, Heverlee, Belgium
| | - Marco Caligaris
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Joëlle Rosseels
- Department of Biology, Functional Biology, KU Leuven, Heverlee, Belgium
| | - Riko Hatakeyama
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Ruben Ghillebert
- Department of Biology, Functional Biology, KU Leuven, Heverlee, Belgium
| | - Belém Sampaio-Marques
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimarães, Braga, Portugal
| | - Kaivalya Mudholkar
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Elja Eskes
- Department of Biology, Functional Biology, KU Leuven, Heverlee, Belgium
| | - Els Meert
- Department of Biology, Functional Biology, KU Leuven, Heverlee, Belgium
| | - Christian Ungermann
- Department of Biology/Chemistry & Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
| | - Paula Ludovico
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
- ICVS/3B’s—PT Government Associate Laboratory, Braga/Guimarães, Braga, Portugal
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Claudio De Virgilio
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- * E-mail: (CDV); (JW)
| | - Joris Winderickx
- Department of Biology, Functional Biology, KU Leuven, Heverlee, Belgium
- * E-mail: (CDV); (JW)
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13
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Zhao F, Zhang Y, Hu J, Shi C, Ao X, Wang S, Lin Y, Sun Z, Han S. Disruption of phosphate metabolism and sterol transport-related genes conferring yeast resistance to vanillin and rapid ethanol production. BIORESOURCE TECHNOLOGY 2023; 369:128489. [PMID: 36528179 DOI: 10.1016/j.biortech.2022.128489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Vanillin is a potent growth-inhibiting factor in Saccharomyces cerevisiae during lignocellulose biorefineries. Here, a haploid gene-deletion library was screened to search for vanillin-tolerant mutants and explain the possible tolerance mechanisms. Twenty-two deletion mutants were identified. The deleted genes in these mutants were involved in phosphate and inositol polyphosphate metabolism and intracellular sterol transport. Activation of the phosphate signaling pathway is not conducive to yeast against the pressure of vanillin. Furthermore, the findings indicate the role of inositol polyphosphates in altering vanillin tolerance by regulating phosphate metabolism. Meanwhile, reducing the transport of sterols from the plasma membrane enhanced tolerance to vanillin. In the presence of vanillin, the representative yeast deletions, pho84Δ and lam3Δ, showed good growth performance and promoted rapid ethanol production. Overall, this study identifies robust yeast strain alternatives for ethanol fermentation of cellulose and provides guidance for further genomic reconstruction of yeast strains.
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Affiliation(s)
- Fengguang Zhao
- School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China; Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China
| | - Yaping Zhang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China
| | - Jian Hu
- School of Light Industry and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Ce Shi
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China
| | - Xiang Ao
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China
| | - Shengding Wang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China
| | - Ying Lin
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China
| | - Zhongwei Sun
- Fleming Biological Pharmaceutical Limited Company, Nanning, 530031, China
| | - Shuangyan Han
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510640, China.
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14
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Zhang S, Nie Y, Fan X, Wei W, Chen H, Xie X, Tang M. A transcriptional activator from Rhizophagus irregularis regulates phosphate uptake and homeostasis in AM symbiosis during phosphorous starvation. Front Microbiol 2023; 13:1114089. [PMID: 36741887 PMCID: PMC9895418 DOI: 10.3389/fmicb.2022.1114089] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 12/28/2022] [Indexed: 01/22/2023] Open
Abstract
Introduction Phosphorus (P) is one of the most important nutrient elements for plant growth and development. Under P starvation, arbuscular mycorrhizal (AM) fungi can promote phosphate (Pi) uptake and homeostasis within host plants. However, the underlying mechanisms by which AM fungal symbiont regulates the AM symbiotic Pi acquisition from soil under P starvation are largely unknown. Here, we identify a HLH domain containing transcription factor RiPho4 from Rhizophagus irregularis. Methods To investigate the biological functions of the RiPho4, we combined the subcellular localization and Yeast One-Hybrid (Y1H) experiments in yeasts with gene expression and virus-induced gene silencing approach during AM symbiosis. Results The approach during AM symbiosis. The results indicated that RiPho4 encodes a conserved transcription factor among different fungi and is induced during the in planta phase. The transcription of RiPho4 is significantly up-regulated by P starvation. The subcellular localization analysis revealed that RiPho4 is located in the nuclei of yeast cells during P starvation. Moreover, knock-down of RiPho4 inhibits the arbuscule development and mycorrhizal Pi uptake under low Pi conditions. Importantly, RiPho4 can positively regulate the downstream components of the phosphate (PHO) pathway in R. irregularis. Discussion In summary, these new findings reveal that RiPho4 acts as a transcriptional activator in AM fungus to maintain arbuscule development and regulate Pi uptake and homeostasis in the AM symbiosis during Pi starvation.
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Affiliation(s)
| | | | | | | | | | - Xianan Xie
- *Correspondence: Xianan Xie, ; Ming Tang,
| | - Ming Tang
- *Correspondence: Xianan Xie, ; Ming Tang,
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15
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Kuenzel NA, Alcázar-Román AR, Saiardi A, Bartsch SM, Daunaraviciute S, Fiedler D, Fleig U. Inositol Pyrophosphate-Controlled Kinetochore Architecture and Mitotic Entry in S. pombe. J Fungi (Basel) 2022; 8:933. [PMID: 36135658 PMCID: PMC9506091 DOI: 10.3390/jof8090933] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/16/2022] Open
Abstract
Inositol pyrophosphates (IPPs) comprise a specific class of signaling molecules that regulate central biological processes in eukaryotes. The conserved Vip1/PPIP5K family controls intracellular IP8 levels, the highest phosphorylated form of IPPs present in yeasts, as it has both inositol kinase and pyrophosphatase activities. Previous studies have shown that the fission yeast S. pombe Vip1/PPIP5K family member Asp1 impacts chromosome transmission fidelity via the modulation of spindle function. We now demonstrate that an IP8 analogue is targeted by endogenous Asp1 and that cellular IP8 is subject to cell cycle control. Mitotic entry requires Asp1 kinase function and IP8 levels are increased at the G2/M transition. In addition, the kinetochore, the conductor of chromosome segregation that is assembled on chromosomes is modulated by IP8. Members of the yeast CCAN kinetochore-subcomplex such as Mal2/CENP-O localize to the kinetochore depending on the intracellular IP8-level: higher than wild-type IP8 levels reduce Mal2 kinetochore targeting, while a reduction in IP8 has the opposite effect. As our perturbations of the inositol polyphosphate and IPP pathways demonstrate that kinetochore architecture depends solely on IP8 and not on other IPPs, we conclude that chromosome transmission fidelity is controlled by IP8 via an interplay between entry into mitosis, kinetochore architecture, and spindle dynamics.
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Affiliation(s)
- Natascha Andrea Kuenzel
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Abel R. Alcázar-Román
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Adolfo Saiardi
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, Gower St., London WC1E 6BT, UK
| | - Simon M. Bartsch
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Sarune Daunaraviciute
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Dorothea Fiedler
- Leibniz Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Ursula Fleig
- Eukaryotic Microbiology, Institute of Functional Microbial Genomics, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany
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16
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Bankaitis VA, Tripathi A, Chen XR, Igumenova TI. New strategies for combating fungal infections: Inhibiting inositol lipid signaling by targeting Sec14 phosphatidylinositol transfer proteins. Adv Biol Regul 2022; 84:100891. [PMID: 35240534 PMCID: PMC9149032 DOI: 10.1016/j.jbior.2022.100891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 02/22/2022] [Indexed: 12/13/2022]
Abstract
Virulent fungi represent a particularly difficult problem in the infectious disease arena as these organisms are eukaryotes that share many orthologous activities with their human hosts. The fact that these activities are often catalyzed by conserved proteins places additional demands on development of pharmacological strategies for specifically inhibiting target fungal activities without imposing undesirable secondary effects on the host. While deployment of a limited set of anti-mycotics has to date satisfied the clinical needs for treatment of fungal infections, the recent emergence of multi-drug resistant fungal 'superbugs' now poses a serious global health threat with rapidly diminishing options for treatment. This escalating infectious disease problem emphasizes the urgent need for development of new classes of anti-mycotics. In that regard, Sec14 phosphatidylinositol transfer proteins offer interesting possibilities for interfering with fungal phosphoinositide signaling with exquisite specificity and without targeting the highly conserved lipid kinases responsible for phosphoinositide production. Herein, we review the establishment of proof-of-principle that demonstrates the feasibility of such an approach. We also describe the lead compounds of four chemotypes that directly target fungal Sec14 proteins. The rules that pertain to the mechanism(s) of Sec14 inhibition by validated small molecule inhibitors, and the open questions that remain, are discussed - as are the challenges that face development of next generation Sec14-directed inhibitors.
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Affiliation(s)
- Vytas A Bankaitis
- Department of Molecular & Cellular Medicine, Texas A&M University, College Station, TX, 77843-0014, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-0014, USA.
| | - Ashutosh Tripathi
- Department of Molecular & Cellular Medicine, Texas A&M University, College Station, TX, 77843-0014, USA
| | - Xiao-Ru Chen
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-0014, USA
| | - Tatyana I Igumenova
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-0014, USA
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17
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Sheng M, Da L, Song Q, Liu Y, Zhang X, Liu F, Xu W, Su Z. Systems biology-based analysis indicates that PHO1;H10 positively modulates high light-induced anthocyanin biosynthesis in Arabidopsis leaves. Genomics 2022; 114:110363. [PMID: 35398515 DOI: 10.1016/j.ygeno.2022.110363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/30/2022] [Accepted: 04/02/2022] [Indexed: 01/14/2023]
Abstract
Arabidopsis PHO1;H10 is a member of the PHO1 gene family with SPX and EXS domains, and its functions remain largely unknown. As shown in PCSD database, the upstream region of PHO1;H10 gene is in the active chromatin states, with high DHS accessibility and binding sites of multiple transcription factors, especially ABI5, SPCH and HY5. Co-expression network and data-mining analyses showed PHO1;H10 and co-expression genes were with activation under high light stress. We did wet-lab experiments, and found that the detached leaves of PHO1;H10 overexpression lines accumulated more anthocyanin than those of WT and mutant under high light treatment. RNA-seq results showed overexpression of PHO1;H10 up-regulated many anthocyanin biosynthetic genes. The GSEA analysis result showed that the functional module related to anthocyanin pathway was significantly enriched. In summary, we conducted systems biology approach, combining dry- and wet-lab analyses, and discovered that PHO1;H10 might play an essential role during modulating high light-induced anthocyanin accumulation in the Arabidopsis detached leaves.
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Affiliation(s)
- Minghao Sheng
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Lingling Da
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qian Song
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yue Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xinyi Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Fengxia Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Wenying Xu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhen Su
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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18
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Mechanistic insights into the regulation of plant phosphate homeostasis by the rice SPX2 - PHR2 complex. Nat Commun 2022; 13:1581. [PMID: 35332155 PMCID: PMC8948245 DOI: 10.1038/s41467-022-29275-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 03/03/2022] [Indexed: 01/21/2023] Open
Abstract
Phosphate (Pi) starvation response (PHR) transcription factors play key roles in plant Pi homeostasis maintenance. They are negatively regulated by stand-alone SPX proteins, cellular receptors for inositol pyrophosphate (PP-InsP) nutrient messengers. How PP-InsP-bound SPX interacts with PHRs is poorly understood. Here, we report crystal structures of the rice SPX2/InsP6/PHR2 complex and of the PHR2 DNA binding (MYB) domain in complex with target DNA at resolutions of 3.1 Å and 2.7 Å, respectively. In the SPX2/InsP6/PHR2 complex, the signalling-active SPX2 assembles into a domain-swapped dimer conformation and binds two copies of PHR2, targeting both its coiled-coil (CC) oligomerisation domain and MYB domain. Our results reveal that the SPX2 senses PP-InsPs to inactivate PHR2 by establishing severe steric clashes with the PHR2 MYB domain, preventing DNA binding, and by disrupting oligomerisation of the PHR2 CC domain, attenuating promoter binding. Our findings rationalize how PP-InsPs activate SPX receptor proteins to target PHR family transcription factors. SPX receptors regulate plant phosphate response via PHR transcription factors. Here, based on crystal structure analysis of rice PHR2 complexes, the authors propose that SPX2 regulates PHR2 by preventing DNA binding and oligomerisation of the PHR2 CC domain.
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19
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Satheesh V, Tahir A, Li J, Lei M. Plant phosphate nutrition: sensing the stress. STRESS BIOLOGY 2022; 2:16. [PMID: 37676547 PMCID: PMC10441931 DOI: 10.1007/s44154-022-00039-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/31/2022] [Indexed: 09/08/2023]
Abstract
Phosphorus (P) is obtained by plants as phosphate (Pi) from the soil and low Pi levels affects plant growth and development. Adaptation to low Pi condition entails sensing internal and external Pi levels and translating those signals to molecular and morphophysiological changes in the plant. In this review, we present findings related to local and systemin Pi sensing with focus the molecular mechanisms behind root system architectural changes and the impact of hormones and epigenetic mechanisms affecting those changes. We also present some of the recent advances in the Pi sensing and signaling mechanisms focusing on inositol pyrophosphate InsP8 and its interaction with SPX domain proteins to regulate the activity of the central regulator of the Pi starvation response, PHR.
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Affiliation(s)
- Viswanathan Satheesh
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602 China
| | - Ayesha Tahir
- Department of Biosciences, COMSATS University Islamabad, Park Road, Islamabad, Pakistan
| | - Jinkai Li
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Mingguang Lei
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602 China
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20
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Cleavage-Polyadenylation Factor Cft1 and SPX Domain Proteins Are Agents of Inositol Pyrophosphate Toxicosis in Fission Yeast. mBio 2022; 13:e0347621. [PMID: 35012333 PMCID: PMC8749416 DOI: 10.1128/mbio.03476-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Inositol pyrophosphate (IPP) dynamics govern expression of the fission yeast phosphate homeostasis regulon via their effects on lncRNA-mediated transcription interference. The growth defects (ranging from sickness to lethality) elicited by fission yeast mutations that inactivate IPP pyrophosphatase enzymes are exerted via the agonistic effects of too much 1,5-IP8 on RNA 3'-processing and transcription termination. To illuminate determinants of IPP toxicosis, we conducted a genetic screen for spontaneous mutations that suppressed the sickness of Asp1 pyrophosphatase mutants. We identified a missense mutation, C823R, in the essential Cft1 subunit of the cleavage and polyadenylation factor complex that suppresses even lethal Asp1 IPP pyrophosphatase mutations, thereby fortifying the case for 3'-processing/termination as the target of IPP toxicity. The suppressor screen also identified Gde1 and Spx1 (SPAC6B12.07c), both of which have an IPP-binding SPX domain and both of which are required for lethality elicited by Asp1 mutations. A survey of other SPX proteins in the proteome identified the Vtc4 and Vtc2 subunits of the vacuolar polyphosphate polymerase as additional agents of IPP toxicosis. Gde1, Spx1, and Vtc4 contain enzymatic modules (glycerophosphodiesterase, RING finger ubiquitin ligase, and polyphosphate polymerase, respectively) fused to their IPP-sensing SPX domains. Structure-guided mutagenesis of the IPP-binding sites and the catalytic domains of Gde1 and Spx1 indicated that both modules are necessary to elicit IPP toxicity. Whereas Vtc4 polymerase catalytic activity is required for IPP toxicity, its IPP-binding site is not. Epistasis analysis, transcriptome profiling, and assays of Pho1 expression implicate Spx1 as a transducer of IP8 signaling to the 3'-processing/transcription termination machinery. IMPORTANCE Impeding the catabolism of the inositol pyrophosphate (IPP) signaling molecule IP8 is cytotoxic to fission yeast. Here, by performing a genetic suppressor screen, we identified several cellular proteins required for IPP toxicosis. Alleviation of IPP lethality by a missense mutation in the essential Cft1 subunit of the cleavage and polyadenylation factor consolidates previous evidence that toxicity results from IP8 action as an agonist of RNA 3'-processing and transcription termination. Novel findings are that IP8 toxicity depends on IPP-sensing SPX domain proteins with associated enzymatic functions: Gde1 (glycerophosphodiesterase), Spx1 (ubiquitin ligase), and Vtc2/4 (polyphosphate polymerase). The effects of Spx1 deletion on phosphate homeostasis imply a role for Spx1 in communicating an IP8-driven signal to the transcription and RNA processing apparatus.
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21
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Phosphate Starvation by Energy Metabolism Disturbance in Candida albicansvip1Δ/Δ Induces Lipid Droplet Accumulation and Cell Membrane Damage. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030686. [PMID: 35163951 PMCID: PMC8839741 DOI: 10.3390/molecules27030686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/11/2022] [Accepted: 01/15/2022] [Indexed: 11/17/2022]
Abstract
Phosphorus in the form of phosphate (Pi) is an essential element for metabolic processes, including lipid metabolism. In yeast, the inositol polyphosphate kinase vip1 mediated synthesis of inositol heptakisphosphate (IP7) regulates the phosphate-responsive (PHO) signaling pathway, which plays an important role in response to Pi stress. The role of vip1 in Pi stress and lipid metabolism of Candida albicans has not yet been studied. We found that when vip1Δ/Δ was grown in glucose medium, if Pi was supplemented in the medium or mitochondrial Pi transporter was overexpressed in the strain, the lipid droplet (LD) content was reduced and membrane damage was alleviated. However, further studies showed that neither the addition of Pi nor the overexpression of the Pi transporter affected the energy balance of vip1Δ/Δ. In addition, the LD content of vip1Δ/Δ grown in Pi limitation medium PNMC was lower than that grown in SC, and the metabolic activity of vip1Δ/Δ grown in PNMC was also lower than that grown in SC medium. This suggests that the increase in Pi demand by a high energy metabolic rate is the cause of LD accumulation in vip1Δ/Δ. In addition, in the vip1Δ/Δ strains, the core transcription factor PHO4 in the PHO pathway was transported to the vacuole and degraded, which reduced the pathway activity. However, this does not mean that knocking out vip1 completely blocks the activation of the PHO pathway, because the LD content of vip1Δ/Δ grown in the medium with β-glycerol phosphate as the Pi source was significantly reduced. In summary, the increased Pi demand and the decreased PHO pathway activity in vip1Δ/Δ ultimately lead to LD accumulation and cell membrane damage.
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22
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Vandermeulen MD, Cullen PJ. Gene by Environment Interactions reveal new regulatory aspects of signaling network plasticity. PLoS Genet 2022; 18:e1009988. [PMID: 34982769 PMCID: PMC8759647 DOI: 10.1371/journal.pgen.1009988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 01/14/2022] [Accepted: 12/09/2021] [Indexed: 11/18/2022] Open
Abstract
Phenotypes can change during exposure to different environments through the regulation of signaling pathways that operate in integrated networks. How signaling networks produce different phenotypes in different settings is not fully understood. Here, Gene by Environment Interactions (GEIs) were used to explore the regulatory network that controls filamentous/invasive growth in the yeast Saccharomyces cerevisiae. GEI analysis revealed that the regulation of invasive growth is decentralized and varies extensively across environments. Different regulatory pathways were critical or dispensable depending on the environment, microenvironment, or time point tested, and the pathway that made the strongest contribution changed depending on the environment. Some regulators even showed conditional role reversals. Ranking pathways' roles across environments revealed an under-appreciated pathway (OPI1) as the single strongest regulator among the major pathways tested (RAS, RIM101, and MAPK). One mechanism that may explain the high degree of regulatory plasticity observed was conditional pathway interactions, such as conditional redundancy and conditional cross-pathway regulation. Another mechanism was that different pathways conditionally and differentially regulated gene expression, such as target genes that control separate cell adhesion mechanisms (FLO11 and SFG1). An exception to decentralized regulation of invasive growth was that morphogenetic changes (cell elongation and budding pattern) were primarily regulated by one pathway (MAPK). GEI analysis also uncovered a round-cell invasion phenotype. Our work suggests that GEI analysis is a simple and powerful approach to define the regulatory basis of complex phenotypes and may be applicable to many systems.
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Affiliation(s)
- Matthew D. Vandermeulen
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Paul J. Cullen
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, United States of America
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23
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Wilson AC, Morgan WR. Functional analysis of a Phytophthora host-translocated effector using the yeast model system. PeerJ 2021; 9:e12576. [PMID: 34966585 PMCID: PMC8663620 DOI: 10.7717/peerj.12576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/09/2021] [Indexed: 11/20/2022] Open
Abstract
Background Phytophthora plant pathogens secrete effector proteins that are translocated into host plant cells during infection and collectively contribute to pathogenicity. A subset of these host-translocated effectors can be identified by the amino acid motif RXLR (arginine, any amino acid, leucine, arginine). Bioinformatics analysis has identified hundreds of putative RXLR effector genes in Phytophthora genomes, but the specific molecular function of most remains unknown. Methods Here we describe initial studies to investigate the use of Saccharomyces cerevisiae as a eukaryotic model to explore the function of Phytophthora RXLR effector proteins. Results and Conclusions Expression of individual RXLR effectors in yeast inhibited growth, consistent with perturbation of a highly conserved cellular process. Transcriptome analysis of yeast cells expressing the poorly characterized P. sojae RXLR effector Avh110 identified nearly a dozen yeast genes whose expression levels were altered greater than two-fold compared to control cells. All five of the most down-regulated yeast genes are normally induced under low phosphate conditions via the PHO4 transcription factor, indicating that PsAvh110 perturbs the yeast regulatory network essential for phosphate homeostasis and suggesting likely PsAvh110 targets during P. sojae infection of its soybean host.
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Affiliation(s)
- Avery C Wilson
- Department of Biology, The College of Wooster, Wooster, OH, United States.,School of Medicine, New York Medical College, Valhalla, NY, United States
| | - William R Morgan
- Department of Biology, The College of Wooster, Wooster, OH, United States
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24
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Shukla A, Kaur M, Kanwar S, Kaur G, Sharma S, Ganguli S, Kumari V, Mazumder K, Pandey P, Rouached H, Rishi V, Bhandari R, Pandey AK. Wheat inositol pyrophosphate kinase TaVIH2-3B modulates cell-wall composition and drought tolerance in Arabidopsis. BMC Biol 2021; 19:261. [PMID: 34895221 PMCID: PMC8665518 DOI: 10.1186/s12915-021-01198-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/22/2021] [Indexed: 02/08/2023] Open
Abstract
Background Inositol pyrophosphates (PP-InsPs) are high-energy derivatives of inositol, involved in different signalling and regulatory responses of eukaryotic cells. Distinct PP-InsPs species are characterized by the presence of phosphate at a variable number of the 6-carbon inositol ring backbone, and two distinct classes of inositol phosphate kinases responsible for their synthesis have been identified in Arabidopsis, namely ITPKinase (inositol 1,3,4 trisphosphate 5/6 kinase) and PP-IP5Kinase (diphosphoinositol pentakisphosphate kinases). Plant PP-IP5Ks are capable of synthesizing InsP8 and were previously shown to control defense against pathogens and phosphate response signals. However, other potential roles of plant PP-IP5Ks, especially towards abiotic stress, remain poorly understood. Results Here, we characterized the physiological functions of two Triticum aestivum L. (hexaploid wheat) PPIP5K homologs, TaVIH1 and TaVIH2. We demonstrate that wheat VIH proteins can utilize InsP7 as the substrate to produce InsP8, a process that requires the functional VIH-kinase domains. At the transcriptional level, both TaVIH1 and TaVIH2 are expressed in different wheat tissues, including developing grains, but show selective response to abiotic stresses during drought-mimic experiments. Ectopic overexpression of TaVIH2-3B in Arabidopsis confers tolerance to drought stress and rescues the sensitivity of Atvih2 mutants. RNAseq analysis of TaVIH2-3B-expressing transgenic lines of Arabidopsis shows genome-wide reprogramming with remarkable effects on genes involved in cell-wall biosynthesis, which is supported by the observation of enhanced accumulation of polysaccharides (arabinogalactan, cellulose, and arabinoxylan) in the transgenic plants. Conclusions Overall, this work identifies a novel function of VIH proteins, implicating them in modulation of the expression of cell-wall homeostasis genes, and tolerance to water-deficit stress. This work suggests that plant VIH enzymes may be linked to drought tolerance and opens up the possibility of future research into using plant VIH-derived products to generate drought-resistant plants. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01198-8.
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Affiliation(s)
- Anuj Shukla
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India.,Regional Centre for Biotechnology, Faridabad - 121001 Haryana (NCR), Delhi, India
| | - Mandeep Kaur
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Swati Kanwar
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Gazaldeep Kaur
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Shivani Sharma
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Shubhra Ganguli
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India.,Graduate Studies, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Vandana Kumari
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Koushik Mazumder
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Pratima Pandey
- Department of Biological Sciences, Indian Institute of Education and Research, Mohali, 140306, India
| | - Hatem Rouached
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA.,Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA
| | - Vikas Rishi
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, 500039, India
| | - Ajay Kumar Pandey
- National Agri-Food Biotechnology Institute (Department of Biotechnology), Sector 81, Knowledge City, S.A.S. Nagar, Mohali-140306, Punjab, India.
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25
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Wang Z, Kuo HF, Chiou TJ. Intracellular phosphate sensing and regulation of phosphate transport systems in plants. PLANT PHYSIOLOGY 2021; 187:2043-2055. [PMID: 35235674 PMCID: PMC8644344 DOI: 10.1093/plphys/kiab343] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/29/2021] [Indexed: 05/04/2023]
Abstract
Recent research on the regulation of cellular phosphate (Pi) homeostasis in eukaryotes has collectively made substantial advances in elucidating inositol pyrophosphates (PP-InsP) as Pi signaling molecules that are perceived by the SPX (Syg1, Pho81, and Xpr1) domains residing in multiple proteins involved in Pi transport and signaling. The PP-InsP-SPX signaling module is evolutionarily conserved across eukaryotes and has been elaborately adopted in plant Pi transport and signaling systems. In this review, we have integrated these advances with prior established knowledge of Pi and PP-InsP metabolism, intracellular Pi sensing, and transcriptional responses according to the dynamics of cellular Pi status in plants. Anticipated challenges and pending questions as well as prospects are also discussed.
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Affiliation(s)
- Zhengrui Wang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Hui-Fen Kuo
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
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26
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Couto D, Richter A, Walter H, Furkert D, Hothorn M, Fiedler D. Using Biotinylated myo-Inositol Hexakisphosphate to Investigate Inositol Pyrophosphate-Protein Interactions with Surface-Based Biosensors. Biochemistry 2021; 60:2739-2748. [PMID: 34499474 DOI: 10.1021/acs.biochem.1c00497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Inositol pyrophosphates (PP-InsPs) are highly phosphorylated molecules that have emerged as central nutrient messengers in eukaryotic organisms. They can bind to structurally diverse target proteins to regulate biological functions, such as protein-protein interactions. PP-InsPs are strongly negatively charged and interact with highly basic surface patches in proteins, making their quantitative biochemical analysis challenging. Here, we present the synthesis of biotinylated myo-inositol hexakisphosphates and their application in surface plasmon resonance and grating-coupled interferometry assays, to enable the rapid identification, validation, and kinetic characterization of InsP- and PP-InsP-protein interactions.
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Affiliation(s)
- Daniel Couto
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Annika Richter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Henriette Walter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - David Furkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Michael Hothorn
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany.,Institute of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
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27
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Moritoh Y, Abe SI, Akiyama H, Kobayashi A, Koyama R, Hara R, Kasai S, Watanabe M. The enzymatic activity of inositol hexakisphosphate kinase controls circulating phosphate in mammals. Nat Commun 2021; 12:4847. [PMID: 34381031 PMCID: PMC8358040 DOI: 10.1038/s41467-021-24934-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 07/15/2021] [Indexed: 12/20/2022] Open
Abstract
Circulating phosphate levels are tightly controlled within a narrow range in mammals. By using a novel small-molecule inhibitor, we show that the enzymatic activity of inositol hexakisphosphate kinases (IP6K) is essential for phosphate regulation in vivo. IP6K inhibition suppressed XPR1, a phosphate exporter, thereby decreasing cellular phosphate export, which resulted in increased intracellular ATP levels. The in vivo inhibition of IP6K decreased plasma phosphate levels without inhibiting gut intake or kidney reuptake of phosphate, demonstrating a pivotal role of IP6K-regulated cellular phosphate export on circulating phosphate levels. IP6K inhibition-induced decrease in intracellular inositol pyrophosphate, an enzymatic product of IP6K, was correlated with phosphate changes. Chronic IP6K inhibition alleviated hyperphosphataemia, increased kidney ATP, and improved kidney functions in chronic kidney disease rats. Our results demonstrate that the enzymatic activity of IP6K regulates circulating phosphate and intracellular ATP and suggest that IP6K inhibition is a potential novel treatment strategy against hyperphosphataemia. Inositol hexakisphosphate kinase (IP6K) is involved in diverse cellular signalling pathways, but the physiological roles of IP6K in vivo remain unknown in mammals. Here, the authors show that the enzymatic activity of IP6K is essential for phosphate regulation in vivo.
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Affiliation(s)
| | - Shin-Ichi Abe
- Research Division, SCOHIA PHARMA Inc, Kanagawa, Japan
| | | | | | | | - Ryoma Hara
- Research Division, SCOHIA PHARMA Inc, Kanagawa, Japan
| | - Shizuo Kasai
- Research Division, SCOHIA PHARMA Inc, Kanagawa, Japan
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28
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The PPIP5K Family Member Asp1 Controls Inorganic Polyphosphate Metabolism in S. pombe. J Fungi (Basel) 2021; 7:jof7080626. [PMID: 34436165 PMCID: PMC8397176 DOI: 10.3390/jof7080626] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 07/30/2021] [Accepted: 07/30/2021] [Indexed: 12/01/2022] Open
Abstract
Inorganic polyphosphate (polyP) which is ubiquitously present in both prokaryotic and eukaryotic cells, consists of up to hundreds of orthophosphate residues linked by phosphoanhydride bonds. The biological role of this polymer is manifold and diverse and in fungi ranges from cell cycle control, phosphate homeostasis and virulence to post-translational protein modification. Control of polyP metabolism has been studied extensively in the budding yeast Saccharomyces cerevisiae. In this yeast, a specific class of inositol pyrophosphates (IPPs), named IP7, made by the IP6K family member Kcs1 regulate polyP synthesis by associating with the SPX domains of the vacuolar transporter chaperone (VTC) complex. To assess if this type of regulation was evolutionarily conserved, we determined the elements regulating polyP generation in the distantly related fission yeast Schizosaccharomyces pombe. Here, the VTC machinery is also essential for polyP generation. However, and in contrast to S. cerevisiae, a different IPP class generated by the bifunctional PPIP5K family member Asp1 control polyP metabolism. The analysis of Asp1 variant S. pombe strains revealed that cellular polyP levels directly correlate with Asp1-made IP8 levels, demonstrating a dose-dependent regulation. Thus, while the mechanism of polyP synthesis in yeasts is conserved, the IPP player regulating polyP metabolism is diverse.
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29
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Regulation of inorganic polyphosphate is required for proper vacuolar proteolysis in fission yeast. J Biol Chem 2021; 297:100891. [PMID: 34147496 PMCID: PMC8294586 DOI: 10.1016/j.jbc.2021.100891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 06/07/2021] [Accepted: 06/16/2021] [Indexed: 02/08/2023] Open
Abstract
Regulation of cellular proliferation and quiescence is a central issue in biology that has been studied using model unicellular eukaryotes, such as the fission yeast Schizosaccharomyces pombe. We previously reported that the ubiquitin/proteasome pathway and autophagy are essential to maintain quiescence induced by nitrogen deprivation in S. pombe; however, specific ubiquitin ligases that maintain quiescence are not fully understood. Here we investigated the SPX-RING-type ubiquitin ligase Pqr1, identified as required for quiescence in a genetic screen. Pqr1 is found to be crucial for vacuolar proteolysis, the final step of autophagy, through proper regulation of phosphate and its polymer polyphosphate. Pqr1 restricts phosphate uptake into the cell through ubiquitination and subsequent degradation of phosphate transporters on plasma membranes. We hypothesized that Pqr1 may act as the central regulator for phosphate control in S. pombe, through the function of the SPX domain involved in phosphate sensing. Deletion of pqr1+ resulted in hyperaccumulation of intracellular phosphate and polyphosphate and in improper autophagy-dependent proteolysis under conditions of nitrogen starvation. Polyphosphate hyperaccumulation in pqr1+-deficient cells was mediated by the polyphosphate synthase VTC complex in vacuoles. Simultaneous deletion of VTC complex subunits rescued Pqr1 mutant phenotypes, including defects in proteolysis and loss of viability during quiescence. We conclude that excess polyphosphate may interfere with proteolysis in vacuoles by mechanisms that as yet remain unknown. The present results demonstrate a connection between polyphosphate metabolism and vacuolar functions for proper autophagy-dependent proteolysis, and we propose that polyphosphate homeostasis contributes to maintenance of cellular viability during quiescence.
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30
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Mohanrao R, Manorama R, Ganguli S, Madhusudhanan MC, Bhandari R, Sureshan KM. Novel Substrates for Kinases Involved in the Biosynthesis of Inositol Pyrophosphates and Their Enhancement of ATPase Activity of a Kinase. Molecules 2021; 26:molecules26123601. [PMID: 34208421 PMCID: PMC8231259 DOI: 10.3390/molecules26123601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/07/2021] [Accepted: 06/07/2021] [Indexed: 11/16/2022] Open
Abstract
IP6K and PPIP5K are two kinases involved in the synthesis of inositol pyrophosphates. Synthetic analogs or mimics are necessary to understand the substrate specificity of these enzymes and to find molecules that can alter inositol pyrophosphate synthesis. In this context, we synthesized four scyllo-inositol polyphosphates-scyllo-IP5, scyllo-IP6, scyllo-IP7 and Bz-scyllo-IP5-from myo-inositol and studied their activity as substrates for mouse IP6K1 and the catalytic domain of VIP1, the budding yeast variant of PPIP5K. We incubated these scyllo-inositol polyphosphates with these kinases and ATP as the phosphate donor. We tracked enzyme activity by measuring the amount of radiolabeled scyllo-inositol pyrophosphate product formed and the amount of ATP consumed. All scyllo-inositol polyphosphates are substrates for both the kinases but they are weaker than the corresponding myo-inositol phosphate. Our study reveals the importance of axial-hydroxyl/phosphate for IP6K1 substrate recognition. We found that all these derivatives enhance the ATPase activity of VIP1. We found very weak ligand-induced ATPase activity for IP6K1. Benzoyl-scyllo-IP5 was the most potent ligand to induce IP6K1 ATPase activity despite being a weak substrate. This compound could have potential as a competitive inhibitor.
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Affiliation(s)
- Raja Mohanrao
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India; (R.M.); (M.C.M.)
| | - Ruth Manorama
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India; (R.M.); (S.G.)
| | - Shubhra Ganguli
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India; (R.M.); (S.G.)
- Manipal Academy of Higher Education, Manipal 576104, India
| | - Mithun C. Madhusudhanan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India; (R.M.); (M.C.M.)
| | - Rashna Bhandari
- Laboratory of Cell Signalling, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500039, India; (R.M.); (S.G.)
- Correspondence: (R.B.); (K.M.S.)
| | - Kana M. Sureshan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala 695551, India; (R.M.); (M.C.M.)
- Correspondence: (R.B.); (K.M.S.)
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31
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Lev S, Bowring B, Desmarini D, Djordjevic JT. Inositol polyphosphate-protein interactions: Implications for microbial pathogenicity. Cell Microbiol 2021; 23:e13325. [PMID: 33721399 PMCID: PMC9286782 DOI: 10.1111/cmi.13325] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/03/2021] [Accepted: 03/07/2021] [Indexed: 11/29/2022]
Abstract
Inositol polyphosphates (IPs) and inositol pyrophosphates (PP-IPs) regulate diverse cellular processes in eukaryotic cells. IPs and PP-IPs are highly negatively charged and exert their biological effects by interacting with specific protein targets. Studies performed predominantly in mammalian cells and model yeasts have shown that IPs and PP-IPs modulate target function through allosteric regulation, by promoting intra- and intermolecular stabilization and, in the case of PP-IPs, by donating a phosphate from their pyrophosphate (PP) group to the target protein. Technological advances in genetics have extended studies of IP function to microbial pathogens and demonstrated that disrupting PP-IP biosynthesis and PP-IP-protein interaction has a profound impact on pathogenicity. This review summarises the complexity of IP-mediated regulation in eukaryotes, including microbial pathogens. It also highlights examples of poor conservation of IP-protein interaction outcome despite the presence of conserved IP-binding domains in eukaryotic proteomes.
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Affiliation(s)
- Sophie Lev
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Bethany Bowring
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
| | - Julianne Teresa Djordjevic
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Sydney, New South Wales, Australia.,Sydney Medical School-Westmead, University of Sydney, Sydney, New South Wales, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, New South Wales, Australia
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32
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Gupta R, Laxman S. Cycles, sources, and sinks: Conceptualizing how phosphate balance modulates carbon flux using yeast metabolic networks. eLife 2021; 10:e63341. [PMID: 33544078 PMCID: PMC7864628 DOI: 10.7554/elife.63341] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/20/2021] [Indexed: 12/11/2022] Open
Abstract
Phosphates are ubiquitous molecules that enable critical intracellular biochemical reactions. Therefore, cells have elaborate responses to phosphate limitation. Our understanding of long-term transcriptional responses to phosphate limitation is extensive. Contrastingly, a systems-level perspective presenting unifying biochemical concepts to interpret how phosphate balance is critically coupled to (and controls) metabolic information flow is missing. To conceptualize such processes, utilizing yeast metabolic networks we categorize phosphates utilized in metabolism into cycles, sources and sinks. Through this, we identify metabolic reactions leading to putative phosphate sources or sinks. With this conceptualization, we illustrate how mass action driven flux towards sources and sinks enable cells to manage phosphate availability during transient/immediate phosphate limitations. We thereby identify how intracellular phosphate availability will predictably alter specific nodes in carbon metabolism, and determine signature cellular metabolic states. Finally, we identify a need to understand intracellular phosphate pools, in order to address mechanisms of phosphate regulation and restoration.
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Affiliation(s)
- Ritu Gupta
- Institute for Stem Cell Science and Regenerative Medicine (inStem)BangaloreIndia
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine (inStem)BangaloreIndia
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33
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Carballar R, Martínez-Láinez JM, Samper B, Bru S, Bállega E, Mirallas O, Ricco N, Clotet J, Jiménez J. CDK-mediated Yku80 Phosphorylation Regulates the Balance Between Non-homologous End Joining (NHEJ) and Homologous Directed Recombination (HDR). J Mol Biol 2020; 432:166715. [PMID: 33217428 DOI: 10.1016/j.jmb.2020.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 11/28/2022]
Abstract
There are two major pathways for repairing DNA double-strand breaks (DSBs): homologous directed recombination (HDR) and non-homologous end-joining (NHEJ). While NHEJ functions throughout the cell cycle, HDR is only possible during S/G2 phases, suggesting that there are cell cycle-specific mechanisms regulating the balance between the two repair systems. The regulation exerted by CDKs on HDR has been extensively demonstrated, and here we present evidence that the CDK Pho85, in association with the G1 cyclin Pcl1, phosphorylates Yku80 on Ser 623 to regulate NHEJ activity. Cells bearing a non-phosphorylatable version of Yku80 show increased NHEJ and reduced HDR activity. Accordingly, yku80S623A cells present diminished viability upon treatment with the DSB-producer bleomycin, specifically in the G2 phase of the cell cycle. Interestingly, the mutation of the equivalent residue in human Ku80 increases sensitivity to bleomycin in several cancer cell lines, suggesting that this mechanism is conserved in humans. Altogether, our results reveal a new mechanism whereby G1-CDKs mediate the choice between HDR and NHEJ repair pathways, putting the error prone NHEJ on a leash and enabling error free HDR in G2 when homologous sequences are available.
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Affiliation(s)
- Reyes Carballar
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Joan M Martínez-Láinez
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Bàrbara Samper
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Samuel Bru
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Elisabet Bállega
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Oriol Mirallas
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Natalia Ricco
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Josep Clotet
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
| | - Javier Jiménez
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain.
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Randez-Gil F, Bojunga L, Estruch F, Winderickx J, Del Poeta M, Prieto JA. Sphingolipids and Inositol Phosphates Regulate the Tau Protein Phosphorylation Status in Humanized Yeast. Front Cell Dev Biol 2020; 8:592159. [PMID: 33282871 PMCID: PMC7705114 DOI: 10.3389/fcell.2020.592159] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 10/21/2020] [Indexed: 01/08/2023] Open
Abstract
Hyperphosphorylation of protein tau is a hallmark of Alzheimer's disease (AD). Changes in energy and lipid metabolism have been correlated with the late onset of this neurological disorder. However, it is uncertain if metabolic dysregulation is a consequence of AD or one of the initiating factors of AD pathophysiology. Also, it is unclear whether variations in lipid metabolism regulate the phosphorylation state of tau. Here, we show that in humanized yeast, tau hyperphosphorylation is stimulated by glucose starvation in coincidence with the downregulation of Pho85, the yeast ortholog of CDK5. Changes in inositol phosphate (IP) signaling, which has a central role in energy metabolism, altered tau phosphorylation. Lack of inositol hexakisphosphate kinases Kcs1 and Vip1 (IP6 and IP7 kinases in mammals) increased tau hyperphosphorylation. Similar effects were found by mutation of IPK2 (inositol polyphosphate multikinase), or PLC1, the yeast phospholipase C gene. These effects may be explained by IP-mediated regulation of Pho85. Indeed, this appeared to be the case for plc1, ipk2, and kcs1. However, the effects of Vip1 on tau phosphorylation were independent of the presence of Pho85, suggesting additional mechanisms. Interestingly, kcs1 and vip1 strains, like pho85, displayed dysregulated sphingolipid (SL) metabolism. Moreover, genetic and pharmacological inhibition of SL biosynthesis stimulated the appearance of hyperphosphorylated forms of tau, while increased flux through the pathway reduced its abundance. Finally, we demonstrated that Sit4, the yeast ortholog of human PP2A protein phosphatase, is a downstream effector of SL signaling in mediating the tau phosphorylation state. Altogether, our results add new knowledge on the molecular effectors involved in tauopathies and identify new targets for pharmacological intervention.
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Affiliation(s)
- Francisca Randez-Gil
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Lino Bojunga
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Francisco Estruch
- Departament of Biochemistry and Molecular Biology, Universitat de València, Valencia, Spain
| | | | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States
- Veterans Administration Medical Center, Northport, NY, United States
| | - Jose A. Prieto
- Department of Biotechnology, Instituto de Agroquímica y Tecnología de los Alimentos, Consejo Superior de Investigaciones Científicas, Valencia, Spain
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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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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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Zhu H, Zhu N, Peng L, Zhang B, Yu Q, Li M. The inositol polyphosphate kinase Ipk1 transcriptionally regulates mitochondrial functions in Candida albicans. FEMS Yeast Res 2020; 20:5896454. [DOI: 10.1093/femsyr/foaa050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/21/2020] [Indexed: 12/22/2022] Open
Abstract
ABSTRACT
Inositol polyphosphates (IPs) is an important family of signaling molecules that regulate multiple cellular processes, such as chromatin remodeling, transcription and mRNA export. Inositol polyphosphate kinases, as the critical enzymes for production and transformation of IPs, directly determine the intracellular levels of IPs and therefore are involved in many cellular processes. However, its roles in Candida albicans, the leading fungal pathogen in human beings, remain to be investigated. In this study, we identified the inositol polyphosphate kinase Ipk1 in C. albicans and found that it localizes in the nucleus. Moreover, in the ipk1Δ/Δ mutant, the activity of mitochondrial respiratory chain complexes and the mitochondrial function was severely impaired, which were associated with down-regulation of mitochondrial function-related genes revealed by transcription profiling analysis. The ipk1Δ/Δ mutant also displayed hypersensitivity to a series of environmental stresses, such as antifungal drugs, oxidants, cell wall perturbing agents and macrophage attacks, followed by attenuation of virulence in a mouse systematic infection model. These findings firstly reported the importance of inositol polyphosphate kinase Ipk1 in C. albicans, especially its role in mitochondrial function maintenance and pathogenicity.
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Affiliation(s)
- Hangqi Zhu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, No. 94, Weijin Road, Tianjin 300071, P. R. China
| | - Nali Zhu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, No. 94, Weijin Road, Tianjin 300071, P. R. China
| | - Liping Peng
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, No. 94, Weijin Road, Tianjin 300071, P. R. China
| | - Bing Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, No. 94, Weijin Road, Tianjin 300071, P. R. China
| | - Qilin Yu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, No. 94, Weijin Road, Tianjin 300071, P. R. China
| | - Mingchun Li
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, College of Life Science, Nankai University, No. 94, Weijin Road, Tianjin 300071, P. R. China
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Furkert D, Hostachy S, Nadler-Holly M, Fiedler D. Triplexed Affinity Reagents to Sample the Mammalian Inositol Pyrophosphate Interactome. Cell Chem Biol 2020; 27:1097-1108.e4. [PMID: 32783964 DOI: 10.1016/j.chembiol.2020.07.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/19/2020] [Accepted: 07/22/2020] [Indexed: 11/15/2022]
Abstract
The inositol pyrophosphates (PP-InsPs) are a ubiquitous group of highly phosphorylated eukaryotic messengers. They have been linked to a panoply of central cellular processes, but a detailed understanding of the discrete signaling events is lacking in most cases. To create a more mechanistic picture of PP-InsP signaling, we sought to annotate the mammalian interactome of the most abundant inositol pyrophosphate 5PP-InsP5. To do so, triplexed affinity reagents were developed, in which a metabolically stable PP-InsP analog was immobilized in three different ways. Application of these triplexed reagents to mammalian lysates identified between 300 and 400 putative interacting proteins. These interactomes revealed connections between 5PP-InsP5 and central cellular regulators, such as lipid phosphatases, protein kinases, and GTPases, and identified protein domains commonly targeted by 5PP-InsP5. Both the triplexed affinity reagents, and the proteomic datasets, constitute powerful resources for the community, to launch future investigations into the multiple signaling modalities of inositol pyrophosphates.
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Affiliation(s)
- David Furkert
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany; Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Michal Nadler-Holly
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Straße 10, 13125 Berlin, Germany; Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany.
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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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Morrissette VA, Rolfes RJ. The intersection between stress responses and inositol pyrophosphates in Saccharomyces cerevisiae. Curr Genet 2020; 66:901-910. [PMID: 32322930 DOI: 10.1007/s00294-020-01078-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/09/2020] [Accepted: 04/11/2020] [Indexed: 01/08/2023]
Abstract
Saccharomyces cerevisiae adapts to oxidative, osmotic stress and nutrient deprivation through transcriptional changes, decreased proliferation, and entry into other developmental pathways such as pseudohyphal formation and sporulation. Inositol pyrophosphates are necessary for these cellular responses. Inositol pyrophosphates are molecules composed of the phosphorylated myo-inositol ring that carries one or more diphosphates. Mutations in the enzymes that metabolize these molecules lead to altered patterns of stress resistance, altered morphology, and defective sporulation. Mechanisms to alter the synthesis of inositol pyrophosphates have been recently described, including inhibition of enzyme activity by oxidation and by phosphorylation. Cells with increased levels of 5-diphosphoinositol pentakisphosphate have increased nuclear localization of Msn2 and Gln3. The altered localization of these factors is consistent with the partially induced environmental stress response and increased expression of genes under the control of Msn2/4 and Gln3. Other transcription factors may also exhibit increased nuclear localization based on increased expression of their target genes. These transcription factors are each regulated by TORC1, suggesting that TORC1 may be inhibited by inositol pyrophosphates. Inositol pyrophosphates affect stress responses in other fungi (Aspergillus nidulans, Ustilago maydis, Schizosaccharomyces pombe, and Cryptococcus neoformans), in human and mouse, and in plants, suggesting common mechanisms and possible novel drug development targets.
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Affiliation(s)
- Victoria A Morrissette
- Department of Biology, Georgetown University, Reiss Science Building 406, Washington, DC, 20057, USA
| | - Ronda J Rolfes
- Department of Biology, Georgetown University, Reiss Science Building 406, Washington, DC, 20057, USA.
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Vip1 is a kinase and pyrophosphatase switch that regulates inositol diphosphate signaling. Proc Natl Acad Sci U S A 2020; 117:9356-9364. [PMID: 32303658 PMCID: PMC7196807 DOI: 10.1073/pnas.1908875117] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Inositol diphosphates (PP-IPs), also known as inositol pyrophosphates, are high-energy cellular signaling codes involved in nutrient and regulatory responses. We report that the evolutionarily conserved gene product, Vip1, possesses autonomous kinase and pyrophosphatase domains capable of synthesis and destruction of D-1 PP-IPs. Our studies provide atomic-resolution structures of the PP-IP products and unequivocally define that the Vip1 gene product is a highly selective 1-kinase and 1-pyrophosphatase enzyme whose activities arise through distinct active sites. Kinetic analyses of kinase and pyrophosphatase parameters are consistent with Vip1 evolving to modulate levels of 1-IP7 and 1,5-IP8 Individual perturbations in kinase and pyrophosphatase activities in cells result in differential effects on vacuolar morphology and osmotic responses. Analogous to the dual-functional key energy metabolism regulator, phosphofructokinase 2, Vip1 is a kinase and pyrophosphatase switch whose 1-PP-IP products play an important role in a cellular adaptation.
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Control of XPR1-dependent cellular phosphate efflux by InsP 8 is an exemplar for functionally-exclusive inositol pyrophosphate signaling. Proc Natl Acad Sci U S A 2020; 117:3568-3574. [PMID: 32019887 DOI: 10.1073/pnas.1908830117] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Homeostasis of cellular fluxes of inorganic phosphate (Pi) supervises its structural roles in bones and teeth, its pervasive regulation of cellular metabolism, and its functionalization of numerous organic compounds. Cellular Pi efflux is heavily reliant on Xenotropic and Polytropic Retrovirus Receptor 1 (XPR1), regulation of which is largely unknown. We demonstrate specificity of XPR1 regulation by a comparatively uncharacterized member of the inositol pyrophosphate (PP-InsP) signaling family: 1,5-bis-diphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8). XPR1-mediated Pi efflux was inhibited by reducing cellular InsP8 synthesis, either genetically (knockout [KO] of diphosphoinositol pentakisphosphate kinases [PPIP5Ks] that synthesize InsP8) or pharmacologically [cell treatment with 2.5 µM dietary flavonoid or 10 µM N2-(m-trifluorobenzyl), N6-(p-nitrobenzyl) purine], to inhibit inositol hexakisphosphate kinases upstream of PPIP5Ks. Attenuated Pi efflux from PPIP5K KO cells was quantitatively phenocopied by KO of XPR1 itself. Moreover, Pi efflux from PPIP5K KO cells was rescued by restoration of InsP8 levels through transfection of wild-type PPIP5K1; transfection of kinase-dead PPIP5K1 was ineffective. Pi efflux was also rescued in a dose-dependent manner by liposomal delivery of a metabolically resistant methylene bisphosphonate (PCP) analog of InsP8; PCP analogs of other PP-InsP signaling molecules were ineffective. High-affinity binding of InsP8 to the XPR1 N-terminus (K d = 180 nM) was demonstrated by isothermal titration calorimetry. To derive a cellular biology perspective, we studied biomineralization in the Soas-2 osteosarcoma cell line. KO of PPIP5Ks or XPR1 strongly reduced Pi efflux and accelerated differentiation to the mineralization end point. We propose that catalytically compromising PPIP5K mutations might extend an epistatic repertoire for XPR1 dysregulation, with pathological consequences for bone maintenance and ectopic calcification.
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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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Metabolic Labeling of Inositol Phosphates and Phosphatidylinositols in Yeast and Mammalian Cells. Methods Mol Biol 2020; 2091:83-92. [PMID: 31773572 DOI: 10.1007/978-1-0716-0167-9_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Inositol phosphate (IP) and phosphatidylinositol (PI) signaling are critical signal transduction pathways responsible for generating numerous receptor-mediated cellular responses. Biochemical and genetic studies have revealed diverse roles of IP and PI signaling in eukaryotic signaling, but detailed characterization of unique IP and PI signaling profiles in response to different agonists and among cell types remains largely unexplored. Here, we outline steady-state inositol metabolic-labeling techniques that can be leveraged to assess the IP and PI signaling state in eukaryotic cells. This flexible technique can be amended and optimized to your cell line of interest, perturbed with biochemical, genetic, or pharmacological alteration, and used to provide comprehensive inositol profiling in various cellular systems.
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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: 46] [Impact Index Per Article: 11.5] [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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46
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Studying the Effects of Inositol Pyrophosphates in an In Vitro Vesicle-Vesicle Fusion Assay. Methods Mol Biol 2019. [PMID: 31773578 DOI: 10.1007/978-1-0716-0167-9_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
In a recent in vitro vesicle fusion study in which we monitored the fusion of reconstituted SNARE and synaptotagmin-containing proteoliposomes, we discovered that inositol pyrophosphate (5-IP7) is a potent inhibitor of neuronal exocytosis. We found that the inhibitory effect of 5-IP7, which is 10 times more potent than those of IP6 and 1-IP7, requires direct interaction with synaptotagmin. Here, we provide a detailed protocol for proteoliposome preparation and bulk observation of proteoliposome fusion based on FRET signals.
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47
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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: 27] [Impact Index Per Article: 5.4] [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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48
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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: 115] [Impact Index Per Article: 23.0] [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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49
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Osorio MB, Ng S, Berkowitz O, De Clercq I, Mao C, Shou H, Whelan J, Jost R. SPX4 Acts on PHR1-Dependent and -Independent Regulation of Shoot Phosphorus Status in Arabidopsis. PLANT PHYSIOLOGY 2019; 181:332-352. [PMID: 31262954 PMCID: PMC6716250 DOI: 10.1104/pp.18.00594] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 05/21/2019] [Indexed: 05/19/2023]
Abstract
Phosphorus (P) is an essential macronutrient for all living organisms and limits plant growth. Four proteins comprising a single SYG1/Pho81/XPR1 (SPX) domain, SPX1 to SPX4, are putative phosphate-dependent inhibitors of Arabidopsis (Arabidopsis thaliana) PHOSPHATE STARVATION RESPONSE1 (PHR1), the master transcriptional activator of phosphate starvation responses. This work demonstrated that SPX4 functions as a negative regulator not only of PHR1-dependent but also of PHR1-independent responses in P-replete plants. Transcriptomes of P-limited spx4 revealed that, unlike SPX1 and SPX2, SPX4 modulates the shoot phosphate starvation response but not short-term recovery after phosphate resupply. In roots, transcriptional regulation of P status is SPX4 independent. Genes misregulated in spx4 shoots intersect with both PHR1-dependent and PHOSPHATE2-dependent signaling networks associated with plant development, senescence, and ion/metabolite transport. Gene regulatory network analyses suggested that SPX4 interacts with transcription factors other than PHR1, such as SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 and ARABIDOPSIS NAC DOMAIN CONTAINING PROTEIN55, known regulators of shoot development. Transient expression studies in protoplasts indicated that PHR1 retention in the cytosol by SPX4 occurs in a dose- and P-status-dependent manner. Using a luciferase reporter in vivo, SPX4 expression kinetics and stability revealed that SPX4 is a short-lived protein with P-status-dependent turnover. SPX4 protein levels were quickly restored by phosphate resupply to P-limited plants. Unlike its monocot ortholog, AtSPX4 was not stabilized by the phosphate analog phosphite, implying that intracellular P status is sensed by its SPX domain via phosphate-rich metabolite signals.
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Affiliation(s)
- Marina Borges Osorio
- Department of Animal, Plant, and Soil Sciences and Centre for AgriBioscience, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Sophia Ng
- Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Perth, Western Australia 6009, Australia
| | - Oliver Berkowitz
- Department of Animal, Plant, and Soil Sciences and Centre for AgriBioscience, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Inge De Clercq
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Chuanzao Mao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zi Jin Gang Campus, Zhejiang University, Hangzhou 310058, China
| | - Huixia Shou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zi Jin Gang Campus, Zhejiang University, Hangzhou 310058, China
| | - James Whelan
- Department of Animal, Plant, and Soil Sciences and Centre for AgriBioscience, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Ricarda Jost
- Department of Animal, Plant, and Soil Sciences and Centre for AgriBioscience, Australian Research Council Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora, Victoria 3086, Australia
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50
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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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