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Vidalle MC, Sheth B, Fazio A, Marvi MV, Leto S, Koufi FD, Neri I, Casalin I, Ramazzotti G, Follo MY, Ratti S, Manzoli L, Gehlot S, Divecha N, Fiume R. Nuclear Phosphoinositides as Key Determinants of Nuclear Functions. Biomolecules 2023; 13:1049. [PMID: 37509085 PMCID: PMC10377365 DOI: 10.3390/biom13071049] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Polyphosphoinositides (PPIns) are signalling messengers representing less than five per cent of the total phospholipid concentration within the cell. Despite their low concentration, these lipids are critical regulators of various cellular processes, including cell cycle, differentiation, gene transcription, apoptosis and motility. PPIns are generated by the phosphorylation of the inositol head group of phosphatidylinositol (PtdIns). Different pools of PPIns are found at distinct subcellular compartments, which are regulated by an array of kinases, phosphatases and phospholipases. Six of the seven PPIns species have been found in the nucleus, including the nuclear envelope, the nucleoplasm and the nucleolus. The identification and characterisation of PPIns interactor and effector proteins in the nucleus have led to increasing interest in the role of PPIns in nuclear signalling. However, the regulation and functions of PPIns in the nucleus are complex and are still being elucidated. This review summarises our current understanding of the localisation, biogenesis and physiological functions of the different PPIns species in the nucleus.
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Affiliation(s)
- Magdalena C Vidalle
- Inositide Laboratory, School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
| | - Bhavwanti Sheth
- Inositide Laboratory, School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
| | - Antonietta Fazio
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Maria Vittoria Marvi
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Stefano Leto
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Foteini-Dionysia Koufi
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Irene Neri
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Irene Casalin
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Giulia Ramazzotti
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Matilde Y Follo
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Stefano Ratti
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Lucia Manzoli
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Sonakshi Gehlot
- Inositide Laboratory, School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
| | - Nullin Divecha
- Inositide Laboratory, School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton, Life Sciences Building 85, Highfield, Southampton SO17 1BJ, UK
| | - Roberta Fiume
- Department of Biomedical Sciences (DIBINEM), University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
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Zarreen F, Kumar K, Chakraborty S. Phosphoinositides in plant-pathogen interaction: trends and perspectives. STRESS BIOLOGY 2023; 3:4. [PMID: 37676371 PMCID: PMC10442044 DOI: 10.1007/s44154-023-00082-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 02/15/2023] [Indexed: 09/08/2023]
Abstract
Phosphoinositides are important regulatory membrane lipids, with a role in plant development and cellular function. Emerging evidence indicates that phosphoinositides play crucial roles in plant defence and are also utilized by pathogens for infection. In this review, we highlight the role of phosphoinositides in plant-pathogen interaction and the implication of this remarkable convergence in the battle against plant diseases.
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Affiliation(s)
- Fauzia Zarreen
- Molecular Virology Laboratory, School of Life Science, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Kamal Kumar
- Molecular Virology Laboratory, School of Life Science, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Science, Jawaharlal Nehru University, New Delhi, 110067, India.
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Khan MHF, Akhtar J, Umer Z, Shaheen N, Shaukat A, Munir MS, Mithani A, Anwar S, Tariq M. Kinome-Wide RNAi Screen Uncovers Role of Ballchen in Maintenance of Gene Activation by Trithorax Group in Drosophila. Front Cell Dev Biol 2021; 9:637873. [PMID: 33748127 PMCID: PMC7973098 DOI: 10.3389/fcell.2021.637873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/15/2021] [Indexed: 12/19/2022] Open
Abstract
Polycomb group (PcG) and trithorax group (trxG) proteins are evolutionary conserved factors that contribute to cell fate determination and maintenance of cellular identities during development of multicellular organisms. The PcG maintains heritable patterns of gene silencing while trxG acts as anti-silencing factors by conserving activation of cell type specific genes. Genetic and molecular analysis has revealed extensive details about how different PcG and trxG complexes antagonize each other to maintain cell fates, however, the cellular signaling components that contribute to the preservation of gene expression by PcG/trxG remain elusive. Here, we report an ex vivo kinome-wide RNAi screen in Drosophila aimed at identifying cell signaling genes that facilitate trxG in counteracting PcG mediated repression. From the list of trxG candidates, Ballchen (BALL), a histone kinase known to phosphorylate histone H2A at threonine 119 (H2AT119p), was characterized as a trxG regulator. The ball mutant exhibits strong genetic interactions with Polycomb (Pc) and trithorax (trx) mutants and loss of BALL affects expression of trxG target genes. BALL co-localizes with Trithorax on chromatin and depletion of BALL results in increased H2AK118 ubiquitination, a histone mark central to PcG mediated gene silencing. Moreover, BALL was found to substantially associate with known TRX binding sites across the genome. Genome wide distribution of BALL also overlaps with H3K4me3 and H3K27ac at actively transcribed genes. We propose that BALL mediated signaling positively contributes to the maintenance of gene activation by trxG in counteracting the repressive effect of PcG.
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Affiliation(s)
- Muhammad Haider Farooq Khan
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Jawad Akhtar
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Zain Umer
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Najma Shaheen
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Ammad Shaukat
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Shahbaz Munir
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Aziz Mithani
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Saima Anwar
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Tariq
- Department of Biology, Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
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Fang F, Ye S, Tang J, Bennett MJ, Liang W. DWT1/DWL2 act together with OsPIP5K1 to regulate plant uniform growth in rice. THE NEW PHYTOLOGIST 2020; 225:1234-1246. [PMID: 31550392 DOI: 10.1111/nph.16216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 09/14/2019] [Indexed: 05/27/2023]
Abstract
Uniform growth of the main shoot and tillers significantly influences rice plant architecture and grain yield. The WUSCHEL-related homeobox transcription factor DWT1 is a key regulator of this important agronomic trait, disruption of which causes enhanced main shoot dominance and tiller dwarfism by an unknown mechanism. Here, we have used yeast-two-hybrid screening to identify OsPIP5K1, a member of the rice phosphatidylinositol-4-phosphate 5-kinase family, as a protein that interacts with DWT1. Cytological analyses confirmed that DWT1 induces accumulation of OsPIP5K1 and its product PI(4,5)P2 , a phosphoinositide secondary messenger, in nuclear bodies. Mutation of OsPIP5K1 compounds the dwarf dwt1 phenotype but abolishes the main shoot dominance. Conversely, overexpression of OsPIP5K1 partially rescues dwt1 developmental defects. Furthermore, we showed that DWL2, the homologue of DWT1, is also able to interact with OsPIP5K1 and shares partial functional redundancy with DWT1 in controlling rice uniformity. Overall, our data suggest that nuclear localised OsPIP5K1 acts with DWT1 and/or DWL2 to coordinate the uniform growth of rice shoots, likely to be through nuclear phosphoinositide signals, and provides insights into the regulation of rice uniformity via a largely unexplored plant nuclear signalling pathway.
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Affiliation(s)
- Fang Fang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 20040, China
| | - Shiwei Ye
- Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 20040, China
| | - Jingyao Tang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 20040, China
| | - Malcolm J Bennett
- Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Wanqi Liang
- Joint International Research Laboratory of Metabolic & Developmental Sciences, State Key Laboratory of Hybrid Rice, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 20040, China
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Nakada-Tsukui K, Watanabe N, Maehama T, Nozaki T. Phosphatidylinositol Kinases and Phosphatases in Entamoeba histolytica. Front Cell Infect Microbiol 2019; 9:150. [PMID: 31245297 PMCID: PMC6563779 DOI: 10.3389/fcimb.2019.00150] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 04/23/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphatidylinositol (PtdIns) metabolism is indispensable in eukaryotes. Phosphoinositides (PIs) are phosphorylated derivatives of PtdIns and consist of seven species generated by reversible phosphorylation of the inositol moieties at the positions 3, 4, and 5. Each of the seven PIs has a unique subcellular and membrane domain distribution. In the enteric protozoan parasite Entamoeba histolytica, it has been previously shown that the PIs phosphatidylinositol 3-phosphate (PtdIns3P), PtdIns(4,5)P2, and PtdIns(3,4,5)P3 are localized to phagosomes/phagocytic cups, plasma membrane, and phagocytic cups, respectively. The localization of these PIs in E. histolytica is similar to that in mammalian cells, suggesting that PIs have orthologous functions in E. histolytica. In contrast, the conservation of the enzymes that metabolize PIs in this organism has not been well-documented. In this review, we summarized the full repertoire of the PI kinases and PI phosphatases found in E. histolytica via a genome-wide survey of the current genomic information. E. histolytica appears to have 10 PI kinases and 23 PI phosphatases. It has a panel of evolutionarily conserved enzymes that generate all the seven PI species. However, class II PI 3-kinases, type II PI 4-kinases, type III PI 5-phosphatases, and PI 4P-specific phosphatases are not present. Additionally, regulatory subunits of class I PI 3-kinases and type III PI 4-kinases have not been identified. Instead, homologs of class I PI 3-kinases and PTEN, a PI 3-phosphatase, exist as multiple isoforms, which likely reflects that elaborate signaling cascades mediated by PtdIns(3,4,5)P3 are present in this organism. There are several enzymes that have the nuclear localization signal: one phosphatidylinositol phosphate (PIP) kinase, two PI 3-phosphatases, and one PI 5-phosphatase; this suggests that PI metabolism also has conserved roles related to nuclear functions in E. histolytica, as it does in model organisms.
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Affiliation(s)
- Kumiko Nakada-Tsukui
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Natsuki Watanabe
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Tomohiko Maehama
- Division of Molecular and Cellular Biology, Graduate School of Medicine, Kobe University, Kobe, Japan
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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6
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Hamann BL, Blind RD. Nuclear phosphoinositide regulation of chromatin. J Cell Physiol 2017; 233:107-123. [PMID: 28256711 DOI: 10.1002/jcp.25886] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 12/26/2022]
Abstract
Phospholipid signaling has clear connections to a wide array of cellular processes, particularly in gene expression and in controlling the chromatin biology of cells. However, most of the work elucidating how phospholipid signaling pathways contribute to cellular physiology have studied cytoplasmic membranes, while relatively little attention has been paid to the role of phospholipid signaling in the nucleus. Recent work from several labs has shown that nuclear phospholipid signaling can have important roles that are specific to this cellular compartment. This review focuses on the nuclear phospholipid functions and the activities of phospholipid signaling enzymes that regulate metazoan chromatin and gene expression. In particular, we highlight the roles that nuclear phosphoinositides play in several nuclear-driven physiological processes, such as differentiation, proliferation, and gene expression. Taken together, the recent discovery of several specifically nuclear phospholipid functions could have dramatic impact on our understanding of the fundamental mechanisms that enable tight control of cellular physiology.
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Affiliation(s)
- Bree L Hamann
- Division of Diabetes Endocrinology and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Raymond D Blind
- Division of Diabetes Endocrinology and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Medicine, Biochemistry and Pharmacology, Division of Diabetes Endocrinology and Metabolism, The Vanderbilt Diabetes Research and Training Center and the Vanderbilt-Ingram Cancer Center, Nashville, Tennessee
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7
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An epigenetic mechanism mediates developmental nicotine effects on neuronal structure and behavior. Nat Neurosci 2016; 19:905-14. [PMID: 27239938 PMCID: PMC4925298 DOI: 10.1038/nn.4315] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/03/2016] [Indexed: 11/24/2022]
Abstract
Developmental nicotine exposure causes persistent changes in cortical neuron morphology and in behavior. We used microarray screening to identify master transcriptional or epigenetic regulators mediating these effects of nicotine and discovered increases in Ash2l, a component of a histone methyltransferase complex. We therefore examined genome-wide changes in H3K4 tri-methylation, a mark induced by the Ash2l complex associated with increased gene transcription. A significant number of regulated promoter sites were involved in synapse maintenance. We found that Mef2c interacts with Ash2l and mediates changes in H3K4 tri-methylation. Knockdown of Ash2l or Mef2c abolishes nicotine-mediated alterations of dendritic complexity in vitro and in vivo, and attenuates nicotine-dependent changes in passive avoidance behavior. In contrast, overexpression mimics nicotine-mediated alterations of neuronal structure and passive avoidance behavior. These studies identify Ash2l as a novel target induced by nicotinic stimulation that couples developmental nicotine exposure to changes in brain epigenetic marks, neuronal structure and behavior.
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Poli A, Billi AM, Mongiorgi S, Ratti S, McCubrey JA, Suh PG, Cocco L, Ramazzotti G. Nuclear Phosphatidylinositol Signaling: Focus on Phosphatidylinositol Phosphate Kinases and Phospholipases C. J Cell Physiol 2015; 231:1645-55. [DOI: 10.1002/jcp.25273] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 12/01/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Alessandro Poli
- Department of Biomedical Sciences; University of Bologna; Bologna Italy
| | - Anna Maria Billi
- Department of Biomedical Sciences; University of Bologna; Bologna Italy
| | - Sara Mongiorgi
- Department of Biomedical Sciences; University of Bologna; Bologna Italy
| | - Stefano Ratti
- Department of Biomedical Sciences; University of Bologna; Bologna Italy
| | - James A. McCubrey
- Department of Microbiology and Immunology; Brody School of Medicine; East Carolina University; Greenville North Carolina
| | - Pann-Ghill Suh
- School of Life Sciences; Ulsan National Institute of Science and Technology; Ulsan Republic of Korea
| | - Lucio Cocco
- Department of Biomedical Sciences; University of Bologna; Bologna Italy
| | - Giulia Ramazzotti
- Department of Biomedical Sciences; University of Bologna; Bologna Italy
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Tan J, Brill JA. Cinderella story: PI4P goes from precursor to key signaling molecule. Crit Rev Biochem Mol Biol 2013; 49:33-58. [PMID: 24219382 DOI: 10.3109/10409238.2013.853024] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Phosphatidylinositol lipids are signaling molecules involved in nearly all aspects of cellular regulation. Production of phosphatidylinositol 4-phosphate (PI4P) has long been recognized as one of the first steps in generating poly-phosphatidylinositol phosphates involved in actin organization, cell migration, and signal transduction. In addition, progress over the last decade has brought to light independent roles for PI4P in membrane trafficking and lipid homeostasis. Here, we describe recent advances that reveal the breadth of processes regulated by PI4P, the spectrum of PI4P effectors, and the mechanisms of spatiotemporal control that coordinate crosstalk between PI4P and cellular signaling pathways.
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Affiliation(s)
- Julie Tan
- Department of Molecular Genetics, University of Toronto , Toronto, Ontario , Canada and
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Yildirim S, Castano E, Sobol M, Philimonenko VV, Dzijak R, Venit T, Hozák P. Involvement of PIP2 in RNA Polymerase I transcription. J Cell Sci 2013; 126:2730-9. [DOI: 10.1242/jcs.123661] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RNA polymerase I (Pol I) transcription is essential for the cell cycle, growth, and overall protein synthesis in eukaryotes. We found that phosphatidylinositol 4,5-bisphosphate (PIP2) is a part of the protein complex on the active ribosomal promoter during the transcription. PIP2 makes a complex with Pol I and Pol I transcription factor UBF in the nucleolus. PIP2 depletion reduces Pol I transcription which can be rescued by the addition of exogenous PIP2. In addition, PIP2 also binds directly to the pre-rRNA processing factor, fibrillarin (Fib), and co-localizes with nascent transcripts in the nucleolus. PIP2 binding to UBF and Fib modulates their binding to DNA and RNA, respectively. In conclusion, PIP2 interacts with a subset of Pol I transcription machinery, and promotes Pol I transcription.
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Dieck CB, Wood A, Brglez I, Rojas-Pierce M, Boss WF. Increasing phosphatidylinositol (4,5) bisphosphate biosynthesis affects plant nuclear lipids and nuclear functions. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 57:32-44. [PMID: 22677448 PMCID: PMC3601448 DOI: 10.1016/j.plaphy.2012.05.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 05/09/2012] [Indexed: 05/21/2023]
Abstract
In order to characterize the effects of increasing phosphatidylinositol(4,5)bisphosphate (PtdIns(4,5)P(2)) on nuclear function, we expressed the human phosphatidylinositol (4)-phosphate 5-kinase (HsPIP5K) 1α in Nicotiana tabacum (NT) cells. The HsPIP5K-expressing (HK) cells had altered nuclear lipids and nuclear functions. HK cell nuclei had 2-fold increased PIP5K activity and increased steady state PtdIns(4,5)P(2). HK nuclear lipid classes showed significant changes compared to NT (wild type) nuclear lipid classes including increased phosphatidylserine (PtdSer) and phosphatidylcholine (PtdCho) and decreased lysolipids. Lipids isolated from protoplast plasma membranes (PM) were also analyzed and compared with nuclear lipids. The lipid profiles revealed similarities and differences in the plasma membrane and nuclei from the NT and transgenic HK cell lines. A notable characteristic of nuclear lipids from both cell types is that PtdIns accounts for a higher mol% of total lipids compared to that of the protoplast PM lipids. The lipid molecular species composition of each lipid class was also analyzed for nuclei and protoplast PM samples. To determine whether expression of HsPIP5K1α affected plant nuclear functions, we compared DNA replication, histone 3 lysine 9 acetylation (H3K9ac) and phosphorylation of the retinoblastoma protein (pRb) in NT and HK cells. The HK cells had a measurable decrease in DNA replication, histone H3K9 acetylation and pRB phosphorylation.
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Affiliation(s)
| | - Austin Wood
- Department of Biochemistry, North Carolina State University, Raleigh, NC
| | - Irena Brglez
- Department of Plant Biology, North Carolina State University, Raleigh, NC
| | | | - Wendy F. Boss
- Department of Plant Biology, North Carolina State University, Raleigh, NC
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Dieck CB, Boss WF, Perera IY. A role for phosphoinositides in regulating plant nuclear functions. FRONTIERS IN PLANT SCIENCE 2012; 3:50. [PMID: 22645589 PMCID: PMC3355785 DOI: 10.3389/fpls.2012.00050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 02/27/2012] [Indexed: 05/21/2023]
Abstract
Nuclear localized inositol phospholipids and inositol phosphates are important for regulating many essential processes in animal and yeast cells such as DNA replication, recombination, RNA processing, mRNA export and cell cycle progression. An overview of the current literature indicates the presence of a plant nuclear phosphoinositide (PI) pathway. Inositol phospholipids, inositol phosphates, and enzymes of the PI pathway have been identified in plant nuclei and are implicated in DNA replication, chromatin remodeling, stress responses and hormone signaling. In this review, the potential functions of the nuclear PI pathway in plants are discussed within the context of the animal and yeast literature. It is anticipated that future research will help shed light on the functional significance of the nuclear PI pathway in plants.
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Affiliation(s)
| | - Wendy F. Boss
- Department of Plant Biology, North Carolina State UniversityRaleigh, NC, USA
| | - Imara Y. Perera
- Department of Plant Biology, North Carolina State UniversityRaleigh, NC, USA
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Fiume R, Keune WJ, Faenza I, Bultsma Y, Ramazzotti G, Jones DR, Martelli AM, Somner L, Follo MY, Divecha N, Cocco L. Nuclear phosphoinositides: location, regulation and function. Subcell Biochem 2012; 59:335-361. [PMID: 22374096 DOI: 10.1007/978-94-007-3015-1_11] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Lipid signalling in human disease is an important field of investigation and stems from the fact that phosphoinositide signalling has been implicated in the control of nearly all the important cellular pathways including metabolism, cell cycle control, membrane trafficking, apoptosis and neuronal conduction. A distinct nuclear inositide signalling metabolism has been identified, thus defining a new role for inositides in the nucleus, which are now considered essential co-factors for several nuclear processes, including DNA repair, transcription regulation, and RNA dynamics. Deregulation of phoshoinositide metabolism within the nuclear compartment may contribute to disease progression in several disorders, such as chronic inflammation, cancer, metabolic, and degenerative syndromes. In order to utilize these very druggable pathways for human benefit there is a need to identify how nuclear inositides are regulated specifically within this compartment and what downstream nuclear effectors process and integrate inositide signalling cascades in order to specifically control nuclear function. Here we describe some of the facets of nuclear inositide metabolism with a focus on their relationship to cell cycle control and differentiation.
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Affiliation(s)
- Roberta Fiume
- Cellular Signalling Laboratory, Department of Human Anatomical Sciences, University of Bologna, Bologna, Italy,
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van den Bout I, Divecha N. PIP5K-driven PtdIns(4,5)P2 synthesis: regulation and cellular functions. J Cell Sci 2009; 122:3837-50. [DOI: 10.1242/jcs.056127] [Citation(s) in RCA: 230] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
It has long been known that phosphoinositides are present in cellular membranes, but only in the past four decades has our understanding of their importance for proper cell function advanced significantly. Key to determining the biological roles of phosphoinositides is understanding the enzymes involved in their metabolism. Although many such enzymes have now been identified, there is still much to learn about their cellular functions. Phosphatidylinositol 4-phosphate 5-kinases (PIP5Ks) are a group of kinases that catalyse the production of phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2]. As well as being a substrate for the enzymes phospholipase C (PLC) and phosphatidylinositol 3-kinase (PI3K), PtdIns(4,5)P2 acts as a second messenger in its own right, influencing a variety of cellular processes. In this Commentary, we review how PIP5Ks are modulated to achieve regulated PtdIns(4,5)P2 production, and discuss the role of these proteins in different cellular processes.
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Affiliation(s)
- Iman van den Bout
- Inositide Laboratory, Paterson Institute for Cancer Research, Wilmslow Road, Manchester M20 4BX, UK
| | - Nullin Divecha
- Inositide Laboratory, Paterson Institute for Cancer Research, Wilmslow Road, Manchester M20 4BX, UK
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15
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Fedorova EV, Pindyurin AV, Baricheva EM. Maintenance of the patterns of expression of homeotic genes in the development of Drosophila melanogaster by proteins of the polycomb, trithorax, and ETP groups. RUSS J GENET+ 2009. [DOI: 10.1134/s1022795409100019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
Phosphoinositides constitute only a small fraction of cellular phospholipids, yet their importance in the regulation of cellular functions can hardly be overstated. The rapid metabolic response of phosphoinositides after stimulation of certain cell surface receptors was the first indication that these lipids could serve as regulatory molecules. These early observations opened research areas that ultimately clarified the plasma membrane role of phosphoinositides in Ca(2+) signaling. However, research of the last 10 years has revealed a much broader range of processes dependent on phosphoinositides. These lipids control organelle biology by regulating vesicular trafficking, and they modulate lipid distribution and metabolism more generally via their close relationship with lipid transfer proteins. Phosphoinositides also regulate ion channels, pumps, and transporters as well as both endocytic and exocytic processes. The significance of phosphoinositides found within the nucleus is still poorly understood, and a whole new research concerns the highly phosphorylated inositols that also appear to control multiple nuclear processes. The expansion of research and interest in phosphoinositides naturally created a demand for new approaches to determine where, within the cell, these lipids exert their effects. Imaging of phosphoinositide dynamics within live cells has become a standard cell biological method. These new tools not only helped us localize phosphoinositides within the cell but also taught us how tightly phosphoinositide control can be linked with distinct effector protein complexes. The recent progress allows us to understand the underlying causes of certain human diseases and design new strategies for therapeutic interventions.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
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Gervais L, Claret S, Januschke J, Roth S, Guichet A. PIP5K-dependent production of PIP2 sustains microtubule organization to establish polarized transport in the Drosophila oocyte. Development 2008; 135:3829-38. [PMID: 18948416 DOI: 10.1242/dev.029009] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The attachment of the cytoskeleton to the plasma membrane is crucial in controlling the polarized transport of cell-fate-determining molecules. Attachment involves adaptor molecules, which have the capacity to bind to both the plasma membrane and elements of the cytoskeleton, such as microtubules and actin filaments. Using the Drosophila oocyte as a model system, we show that the type I phosphatidylinositol 4-phosphate 5-kinase (PIP5K), Skittles, is necessary to sustain the organization of microtubules and actin cytoskeleton required for the asymmetric transport of oskar, bicoid and gurken mRNAs and thereby controls the establishment of cell polarity. We show that Skittles function is crucial to synthesize and maintain phosphatidylinositol 4,5 bisphosphate (PIP2) at the plasma membrane in the oocyte. Reduction of Skittles activity impairs activation at the plasma membrane of Moesin, a member of the ERM family known to link the plasma membrane to the actin-based cytoskeleton. Furthermore, we provide evidence that Skittles, by controlling the localization of Bazooka, Par-1 and Lgl, but not Lkb1, to the cell membrane, regulates PAR polarity proteins and the maintenance of specific cortical domains along the anteroposterior axis.
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Affiliation(s)
- Louis Gervais
- Institut Jacques Monod, Unité Mixte de Recherche 7592, CNRS, Universités Paris 7, 2 place Jussieu, F-75251, Paris Cedex 05, France
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18
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Overexpression of partner of numb induces asymmetric distribution of the PI4P 5-Kinase Skittles in mitotic sensory organ precursor cells in Drosophila. PLoS One 2008; 3:e3072. [PMID: 18728778 PMCID: PMC2516928 DOI: 10.1371/journal.pone.0003072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Accepted: 05/09/2008] [Indexed: 11/19/2022] Open
Abstract
Unequal segregation of cell fate determinants at mitosis is a conserved mechanism whereby cell fate diversity can be generated during development. In Drosophila, each sensory organ precursor cell (SOP) divides asymmetrically to produce an anterior pIIb and a posterior pIIa cell. The Par6-aPKC complex localizes at the posterior pole of dividing SOPs and directs the actin-dependent localization of the cell fate determinants Numb, Partner of Numb (Pon) and Neuralized at the opposite pole. The plasma membrane lipid phosphatidylinositol (4,5)-bisphosphate (PIP2) regulates the plasma membrane localization and activity of various proteins, including several actin regulators, thereby modulating actin-based processes. Here, we have examined the distribution of PIP2 and of the PIP2-producing kinase Skittles (Sktl) in mitotic SOPs. Our analysis indicates that both Sktl and PIP2 reporters are uniformly distributed in mitotic SOPs. In the course of this study, we have observed that overexpression of full-length Pon or its localization domain (LD) fused to the Red Fluorescent Protein (RFP::PonLD) results in asymmetric distribution of Sktl and PIP2 reporters in dividing SOPs. Our observation that Pon overexpression alters polar protein distribution is relevant because RFP::PonLD is often used as a polarity marker in dividing progenitors.
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Beltran S, Angulo M, Pignatelli M, Serras F, Corominas M. Functional dissection of the ash2 and ash1 transcriptomes provides insights into the transcriptional basis of wing phenotypes and reveals conserved protein interactions. Genome Biol 2007; 8:R67. [PMID: 17466076 PMCID: PMC1896016 DOI: 10.1186/gb-2007-8-4-r67] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 03/05/2007] [Accepted: 04/28/2007] [Indexed: 12/16/2022] Open
Abstract
Analysis of the gene expression profiles of wing imaginal discs from ash2 and ash1 mutants shows that they are highly similar, supporting a model in which they act together to maintain stable states of transcription. Background The trithorax group (trxG) genes absent, small or homeotic discs 1 (ash1) and 2 (ash2) were isolated in a screen for mutants with abnormal imaginal discs. Mutations in either gene cause homeotic transformations but Hox genes are not their only targets. Although analysis of double mutants revealed that ash2 and ash1 mutations enhance each other's phenotypes, suggesting they are functionally related, it was shown that these proteins are subunits of distinct complexes. Results The analysis of wing imaginal disc transcriptomes from ash2 and ash1 mutants showed that they are highly similar. Functional annotation of regulated genes using Gene Ontology allowed identification of severely affected groups of genes that could be correlated to the wing phenotypes observed. Comparison of the differentially expressed genes with those from other genome-wide analyses revealed similarities between ASH2 and Sin3A, suggesting a putative functional relationship. Coimmunoprecipitation studies and immunolocalization on polytene chromosomes demonstrated that ASH2 and Sin3A interact with HCF (host-cell factor). The results of nucleosome western blots and clonal analysis indicated that ASH2 is necessary for trimethylation of the Lys4 on histone 3 (H3K4). Conclusion The similarity between the transcriptomes of ash2 and ash1 mutants supports a model in which the two genes act together to maintain stable states of transcription. Like in humans, both ASH2 and Sin3A bind HCF. Finally, the reduction of H3K4 trimethylation in ash2 mutants is the first evidence in Drosophila regarding the molecular function of this trxG gene.
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Affiliation(s)
- Sergi Beltran
- Departament de Genètica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Mireia Angulo
- Departament de Genètica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Miguel Pignatelli
- Departament de Genètica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Florenci Serras
- Departament de Genètica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Montserrat Corominas
- Departament de Genètica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
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Mao YS, Yin HL. Regulation of the actin cytoskeleton by phosphatidylinositol 4-phosphate 5 kinases. Pflugers Arch 2007; 455:5-18. [PMID: 17520274 DOI: 10.1007/s00424-007-0286-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 05/02/2007] [Indexed: 12/19/2022]
Abstract
Phosphatidylinositol (4,5)-bisphosphate (PIP(2)) is an important lipid mediator that has multiple regulatory functions. There is now increasing evidence that the phosphatidylinositol 4-phosphate 5 kinases (PIP5Ks), which synthesize PIP(2), are regulated spatially and temporally and that they have isoform-specific functions and regulations. This review will summarize the highlights of recent developments in understanding how the three major PIP5K isoforms regulate the actin cytoskeleton and other important cellular processes.
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Affiliation(s)
- Yuntao S Mao
- Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9040, USA
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21
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Secombe J, Li L, Carlos L, Eisenman RN. The Trithorax group protein Lid is a trimethyl histone H3K4 demethylase required for dMyc-induced cell growth. Genes Dev 2007; 21:537-51. [PMID: 17311883 PMCID: PMC1820896 DOI: 10.1101/gad.1523007] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The Myc oncoprotein is a potent inducer of cell growth, cell cycle progression, and apoptosis. While many direct Myc target genes have been identified, the molecular determinants of Myc's transcriptional specificity remain elusive. We have carried out a genetic screen in Drosophila and identified the Trithorax group protein Little imaginal discs (Lid) as a regulator of dMyc-induced cell growth. Lid binds to dMyc and is required for dMyc-induced expression of the growth regulatory gene Nop60B. The mammalian Lid orthologs, Rbp-2 (JARID1A) and Plu-1 (JARID1B), also bind to c-Myc, indicating that Lid-Myc function is conserved. We demonstrate that Lid is a JmjC-dependent trimethyl H3K4 demethylase in vivo and that this enzymatic activity is negatively regulated by dMyc, which binds to Lid's JmjC domain. Because Myc binding is associated with high levels of trimethylated H3K4, we propose that the Lid-dMyc complex facilitates Myc binding to, or maintenance of, this chromatin context.
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Affiliation(s)
- Julie Secombe
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Ling Li
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Leni Carlos
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Robert N. Eisenman
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
- Corresponding author.E-MAIL ; FAX (206) 667-6522
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Seeds AM, Frederick JP, Tsui MMK, York JD. Roles for inositol polyphosphate kinases in the regulation of nuclear processes and developmental biology. ACTA ACUST UNITED AC 2007; 47:10-25. [PMID: 17467778 PMCID: PMC3258027 DOI: 10.1016/j.advenzreg.2006.12.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | | | | | - John D. York
- To whom correspondence should be addressed: Department of Pharmacology and Cancer Biology, Howard Hughes Medical Institute, Duke University Medical Center, DUMC 3813, Durham, NC 27710, Tel: 919-681-6414, Fax: 919-668-0991, E-mail:
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23
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Guertin DA, Guntur KVP, Bell GW, Thoreen CC, Sabatini DM. Functional genomics identifies TOR-regulated genes that control growth and division. Curr Biol 2006; 16:958-70. [PMID: 16713952 DOI: 10.1016/j.cub.2006.03.084] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 03/09/2006] [Accepted: 03/22/2006] [Indexed: 01/08/2023]
Abstract
BACKGROUND The TOR (target of rapamycin) ser/thr protein kinase is the central component of a eukaryotic signaling pathway that regulates growth and is the direct target of the clinically useful drug rapamycin. Recent efforts have identified at least two multiprotein complexes that contain TOR, but little is known in higher eukaryotes about the genes downstream of TOR that control growth. RESULTS By combining the use of a small molecule inhibitor (rapamycin), transcriptional profiling, and RNA interference in Drosophila tissue culture cells, we identified genes whose expression responds to Drosophila TOR (dTOR) inhibition and that regulate cell size. Several of the dTOR-regulated genes that function in cell size control have additional roles in cell division. Most of these genes are conserved in mammals and several are linked to human disease. This set of genes is highly enriched for regulators of ribosome biogenesis, which emphasizes the importance of TOR-dependent transcription in building the protein synthesis machinery in higher eukaryotes. In addition, we identify two dTOR-regulated genes, CG3071 and CG6677, whose human orthologs, SAW and ASH2L, are also under TOR-dependent transcriptional control and encode proteins with conserved functional roles in growth. CONCLUSIONS We conclude that combining RNA interference with genomic analysis approaches, such as transcriptional profiling, is an effective way to identify genes functioning in a particular biological process. Moreover, this strategy, if applied in model systems with simpler genomes, can identify genes with conserved functions in mammals.
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Affiliation(s)
- David A Guertin
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA
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24
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York JD. Regulation of nuclear processes by inositol polyphosphates. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:552-9. [PMID: 16781889 DOI: 10.1016/j.bbalip.2006.04.014] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Accepted: 04/18/2006] [Indexed: 11/18/2022]
Abstract
Inositide signaling pathways represent a multifaceted ensemble of cellular switches capable of regulating a number of processes, for example, intracellular calcium release, membrane trafficking, chemotaxis, ion channel activity and several nuclear functions. Over 30 inositide messengers are found in eukaryotic cells that may be grouped into two classes: (1) inositol lipids, phosphatidylinositols or phosphoinositides (PIPs) and (2) water-soluble inositol polyphosphates (IPs). This review will focus on inositol polyphosphate kinases (IPK) and inositol pyrophosphate synthases (IPS) responsible for the cellular production of IP(4), IP(5) IP(6) and PP-IPs. Of interest, IPK and IPS proteins localize, in part, within the nucleus and their activities are necessary for proper regulation of gene expression, mRNA export, DNA repair and telomere maintenance. The breadth of nuclear processes regulated and the evolutionary conservation of the genes involved in their synthesis have sparked renewed interest in inositide messengers derived from sequential phosphorylation of inositol 1,4,5-trisphosphate.
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Affiliation(s)
- John D York
- Departments of Pharmacology and Cancer Biology and of Biochemistry, Howard Hughes Medical Institute, Duke University Medical Center, Box 3813, Durham, NC 27710, USA.
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25
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Alvarez-Venegas R, Sadder M, Hlavacka A, Baluška F, Xia Y, Lu G, Firsov A, Sarath G, Moriyama H, Dubrovsky JG, Avramova Z. The Arabidopsis homolog of trithorax, ATX1, binds phosphatidylinositol 5-phosphate, and the two regulate a common set of target genes. Proc Natl Acad Sci U S A 2006; 103:6049-54. [PMID: 16585509 PMCID: PMC1458695 DOI: 10.1073/pnas.0600944103] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Indexed: 01/04/2023] Open
Abstract
The Arabidopsis homolog of trithorax, ATX1, regulates numerous functions in Arabidopsis beyond the homeotic genes. Here, we identified genome-wide targets of ATX1 and showed that ATX1 is a receptor for a lipid messenger, phosphatidylinositol 5-phosphate, PI5P. PI5P negatively affects ATX1 activity, suggesting a regulatory pathway connecting lipid-signaling with nuclear functions. We propose a model to illustrate how plants may respond to stimuli (external or internal) that elevate cellular PI5P levels by altering expression of ATX1-controlled genes.
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Affiliation(s)
| | - Monther Sadder
- *School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118
| | - Andrej Hlavacka
- Department of Plant Cell Biology, Institute of Botany, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | - František Baluška
- Department of Plant Cell Biology, Institute of Botany, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | | | - Guoqing Lu
- *School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118
- Bioinformatics Core Research Facility, Center for Biotechnology, University of Nebraska, Lincoln, NE 68588-0665
| | - Alexey Firsov
- *School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118
| | - Gautam Sarath
- United States Department of Agriculture, Agricultural Research Service Unit, East Campus, University of Nebraska, Lincoln, NE 68583-0939
| | - Hideaki Moriyama
- **Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304; and
| | - Joseph G. Dubrovsky
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, Cuernavaca Morelos, CP 62250, Mexico
| | - Zoya Avramova
- *School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118
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Bunce MW, Bergendahl K, Anderson RA. Nuclear PI(4,5)P(2): a new place for an old signal. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:560-9. [PMID: 16750654 DOI: 10.1016/j.bbalip.2006.03.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2005] [Revised: 03/03/2006] [Accepted: 03/03/2006] [Indexed: 10/24/2022]
Abstract
Over the last decades, evidence has accumulated suggesting that there is a distinct nuclear phosphatidylinositol pathway. One of the best examined nuclear lipid pathways is the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PI4,5P(2)) by PLC resulting in activation of nuclear PKC and production of inositol polyphosphates. However, there is a growing number of data that phosphoinositides are not only precursor for soluble inositol phosphates and diacylglycerol, instead they can act as second messengers themselves. They have been implicated to play a role in different important nuclear signaling events such as cell cycle progression, apoptosis, chromatin remodeling, transcriptional regulation and mRNA processing. This review focuses on the role of specifically PI4,5P(2) in the nucleus as a second messenger as well as a precursor for PI3,4,5P3, inositol polyphosphates and diacylglycerol.
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Affiliation(s)
- Matthew W Bunce
- Department of Pharmacology, University of Wisconsin Medical School, 1300 University Ave., Madison, WI 53706, USA
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27
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Cocco L, Martelli AM, Fiume R, Faenza I, Billi AM, Manzoli FA. Signal transduction within the nucleus: Revisiting phosphoinositide inositide–specific phospholipase Cβ1. ACTA ACUST UNITED AC 2006; 46:2-11. [PMID: 16846636 DOI: 10.1016/j.advenzreg.2006.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Lucio Cocco
- Cellular Signaling Laboratory, Department of Anatomical Sciences, University of Bologna, via Irnerio 48, 40126 Bologna, Italy.
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28
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Martelli AM, Follo MY, Evangelisti C, Falà F, Fiume R, Billi AM, Cocco L. Nuclear inositol lipid metabolism: more than just second messenger generation? J Cell Biochem 2005; 96:285-92. [PMID: 16088939 DOI: 10.1002/jcb.20527] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A distinct polyphosphoinositide cycle is present in the nucleus, and growing evidence suggests its importance in DNA replication, gene transcription, and apoptosis. Even though it was initially thought that nuclear inositol lipids would function as a source for second messengers, recent findings strongly indicate that lipids present in the nucleus also fulfil other roles. The scope of this review is to highlight the most intriguing advances made in the field over the last few years, such as the possibility that nuclear phosphatidylinositol (4,5) bisphosphate is involved in maintaining chromatin in a transcriptionally active conformation, the new emerging roles for intranuclear phosphatidylinositol (3,4,5) trisphosphate and phosphoinositide 3-kinase, and the evidence which suggests a tight relationship between a decreased level of nuclear phosphoinositide specific phospholipase C-beta1 and the evolution of myelodisplastic syndrome into acute myeloid leukemia.
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Affiliation(s)
- Alberto M Martelli
- Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Sezione di Anatomia Umana, Cell Signalling Laboratory, Università di Bologna, 40126 Bologna, Italy
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Abstract
The main epigenetic mechanisms in regulation of gene expression are discussed. The definition of epigenetics and its specific mechanisms including DNA methylation and gene imprinting, modifications of nucleosomal histones associated with silencing or activation of gene transcription, RNA interference, chromosomal silencing, and the role of mobile elements are discussed.
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Affiliation(s)
- N A Tchurikov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
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