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Fang Y, Jiang J, Ding H, Li X, Xie X. Phospholipase C: Diverse functions in plant biotic stress resistance and fungal pathogenicity. MOLECULAR PLANT PATHOLOGY 2023; 24:1192-1202. [PMID: 37119461 PMCID: PMC10423330 DOI: 10.1111/mpp.13343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/10/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
Phospholipase C (PLC) generates various second messenger molecules and mediates phospholipid hydrolysis. In recent years, the important roles of plant and fungal PLC in disease resistance and pathogenicity, respectively, have been determined. However, the roles of PLC in plants and fungi are unintegrated and relevant literature is disorganized. This makes it difficult for researchers to implement PLC-based strategies to improve disease resistance in plants. In this comprehensive review, we summarize the structure, classification, and phylogeny of the PLCs involved in plant biotic stress resistance and fungal pathogenicity. PLCs can be divided into two groups, nonspecific PLC (NPC) and phosphatidylinositol-specific PLC (PI-PLC), which present marked differences in phylogenetic evolution. The products of PLC genes in fungi play significant roles in physiological activity and pathogenesis, whereas those encoded by plant PLC genes mediate the immune response to fungi. This review provides a perspective for the future control of plant fungal diseases.
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Affiliation(s)
- Yuanpeng Fang
- Key Laboratory of Agricultural MicrobiologyCollege of Agriculture, Guizhou UniversityGuiyangChina
| | - Junmei Jiang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of Education, Guizhou UniversityGuiyangChina
| | - Haixia Ding
- Key Laboratory of Agricultural MicrobiologyCollege of Agriculture, Guizhou UniversityGuiyangChina
| | - Xiangyang Li
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of Education, Guizhou UniversityGuiyangChina
| | - Xin Xie
- Key Laboratory of Agricultural MicrobiologyCollege of Agriculture, Guizhou UniversityGuiyangChina
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2
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Bhagwat M, Nagar S, Kaur P, Mehta R, Vancurova I, Vancura A. Replication stress inhibits synthesis of histone mRNAs in yeast by removing Spt10p and Spt21p from the histone promoters. J Biol Chem 2021; 297:101246. [PMID: 34582893 PMCID: PMC8551654 DOI: 10.1016/j.jbc.2021.101246] [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: 06/09/2021] [Revised: 09/17/2021] [Accepted: 09/23/2021] [Indexed: 12/27/2022] Open
Abstract
Proliferating cells coordinate histone and DNA synthesis to maintain correct stoichiometry for chromatin assembly. Histone mRNA levels must be repressed when DNA replication is inhibited to prevent toxicity and genome instability due to free non-chromatinized histone proteins. In mammalian cells, replication stress triggers degradation of histone mRNAs, but it is unclear if this mechanism is conserved from other species. The aim of this study was to identify the histone mRNA decay pathway in the yeast Saccharomyces cerevisiae and determine the mechanism by which DNA replication stress represses histone mRNAs. Using reverse transcription-quantitative PCR and chromatin immunoprecipitation–quantitative PCR, we show here that histone mRNAs can be degraded by both 5′ → 3′ and 3′ → 5′ pathways; however, replication stress does not trigger decay of histone mRNA in yeast. Rather, replication stress inhibits transcription of histone genes by removing the histone gene–specific transcription factors Spt10p and Spt21p from histone promoters, leading to disassembly of the preinitiation complexes and eviction of RNA Pol II from histone genes by a mechanism facilitated by checkpoint kinase Rad53p and histone chaperone Asf1p. In contrast, replication stress does not remove SCB-binding factor transcription complex, another activator of histone genes, from the histone promoters, suggesting that Spt10p and Spt21p have unique roles in the transcriptional downregulation of histone genes during replication stress. Together, our data show that, unlike in mammalian cells, replication stress in yeast does not trigger decay of histone mRNAs but inhibits histone transcription.
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Affiliation(s)
- Madhura Bhagwat
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Shreya Nagar
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Pritpal Kaur
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Riddhi Mehta
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Ivana Vancurova
- Department of Biological Sciences, St John's University, Queens, New York, USA
| | - Ales Vancura
- Department of Biological Sciences, St John's University, Queens, New York, USA.
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Huang S, Benben A, Green R, Cheranda N, Lee G, Joseph B, Keaveney S, Wang Y. Phosphorylation of the Gα protein Gpa2 promotes protein kinase A signaling in yeast. J Biol Chem 2019; 294:18836-18845. [PMID: 31690628 DOI: 10.1074/jbc.ra119.009609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/31/2019] [Indexed: 01/10/2023] Open
Abstract
Heterotrimeric G proteins are important molecular switches that facilitate transmission of a variety of signals from the outside to the inside of cells. G proteins are highly conserved, enabling study of their regulatory mechanisms in model organisms such as the budding yeast Saccharomyces cerevisiae Gpa2 is a yeast Gα protein that functions in the nutrient signaling pathway. Using Phos-tag, a highly specific phosphate binding tag for separating phosphorylated proteins, we found that Gpa2 undergoes phosphorylation and that its level of phosphorylation is markedly increased upon nitrogen starvation. We also observed that phosphorylation of Gpa2 depends on glycogen synthase kinase (GSK). Disrupting GSK activity diminishes Gpa2 phosphorylation levels in vivo, and the purified GSK isoforms Mck1 and Ygk3 are capable of phosphorylating Gpa2 in vitro Functionally, phosphorylation enhanced plasma membrane localization of Gpa2 and promoted nitrogen starvation-induced activation of protein kinase A. Together, the findings of our study reveal a mechanism by which GSK- and nutrient-dependent phosphorylation regulates subcellular localization of Gpa2 and its ability to activate downstream signaling.
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Affiliation(s)
- Shan Huang
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Alex Benben
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Robert Green
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Nina Cheranda
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Grace Lee
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Benita Joseph
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Shannon Keaveney
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103
| | - Yuqi Wang
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103.
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4
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Phospholipases play multiple cellular roles including growth, stress tolerance, sexual development, and virulence in fungi. Microbiol Res 2018; 209:55-69. [DOI: 10.1016/j.micres.2017.12.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 12/21/2017] [Accepted: 12/31/2017] [Indexed: 12/16/2022]
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5
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Zhang T, Galdieri L, Hasek J, Vancura A. Yeast phospholipase C is required for stability of casein kinase I Yck2p and expression of hexose transporters. FEMS Microbiol Lett 2017; 364:4566517. [PMID: 29087456 DOI: 10.1093/femsle/fnx227] [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: 06/08/2017] [Accepted: 10/25/2017] [Indexed: 11/12/2022] Open
Abstract
Phospholipase C (Plc1p) in Saccharomyces cerevisiae is required for normal degradation of repressor Mth1p and expression of the HXT genes encoding cell membrane transporters of glucose. Plc1p is also required for normal localization of glucose transporters to the cell membrane. Consequently, plc1Δ cells display histone hypoacetylation and transcriptional defects due to reduced uptake and metabolism of glucose to acetyl-CoA, a substrate for histone acetyltransferases. In the presence of glucose, Mth1p is phosphorylated by casein kinase I Yck1/2p, ubiquitinated by the SCFGrr1 complex and degraded by the proteasome. Here, we show that while Plc1p does not affect the function of the SCFGrr1 complex or the proteasome, it is required for normal protein level of Yck2p. Since stability of Yck1/2p is regulated by a glucose-dependent mechanism, PLC1 inactivation results in destabilization of Yck1/2p and defect in Mth1p degradation. Based on our results and published data, we propose a model in which plc1Δ mutation causes increased internalization of glucose transporters, decreased transport of glucose into the cells, and consequently decreased stability of Yck1/2p, increased stability of Mth1p and decreased expression of the HXT genes.
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Affiliation(s)
- Tiantian Zhang
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, USA
| | - Luciano Galdieri
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, USA
| | - Jiri Hasek
- Laboratory of Cell Reproduction, Institute of Microbiology CAS, v.v.i., Videnska 1083, Prague 14220, Czech Republic
| | - Ales Vancura
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, USA
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Eskes E, Deprez MA, Wilms T, Winderickx J. pH homeostasis in yeast; the phosphate perspective. Curr Genet 2017; 64:155-161. [PMID: 28856407 PMCID: PMC5778149 DOI: 10.1007/s00294-017-0743-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 12/22/2022]
Abstract
Recent research further clarified the molecular mechanisms that link nutrient signaling and pH homeostasis with the regulation of growth and survival of the budding yeast Saccharomyces cerevisiae. The central nutrient signaling kinases PKA, TORC1, and Sch9 are intimately associated to pH homeostasis, presumably allowing them to concert far-reaching phenotypical repercussions of nutritional cues. To exemplify such repercussions, we briefly describe consequences for phosphate uptake and signaling and outline interactions between phosphate homeostasis and the players involved in intra- and extracellular pH control. Inorganic phosphate uptake, its subcellular distribution, and its conversion into polyphosphates are dependent on the proton gradients created over different membranes. Conversely, polyphosphate metabolism appears to contribute in determining the intracellular pH. Additionally, inositol pyrophosphates are emerging as potent determinants of growth potential, in this way providing feedback from phosphate metabolism onto the central nutrient signaling kinases. All these data point towards the importance of phosphate metabolism in the reciprocal regulation of nutrient signaling and pH homeostasis.
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Affiliation(s)
- Elja Eskes
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31 box 2433, 3001, Heverlee, Belgium
| | - Marie-Anne Deprez
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31 box 2433, 3001, Heverlee, Belgium
| | - Tobias Wilms
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31 box 2433, 3001, Heverlee, Belgium
| | - Joris Winderickx
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31 box 2433, 3001, Heverlee, Belgium.
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Engelberg D, Perlman R, Levitzki A. Transmembrane signaling in Saccharomyces cerevisiae as a model for signaling in metazoans: state of the art after 25 years. Cell Signal 2014; 26:2865-78. [PMID: 25218923 DOI: 10.1016/j.cellsig.2014.09.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 09/02/2014] [Indexed: 02/07/2023]
Abstract
In the very first article that appeared in Cellular Signalling, published in its inaugural issue in October 1989, we reviewed signal transduction pathways in Saccharomyces cerevisiae. Although this yeast was already a powerful model organism for the study of cellular processes, it was not yet a valuable instrument for the investigation of signaling cascades. In 1989, therefore, we discussed only two pathways, the Ras/cAMP and the mating (Fus3) signaling cascades. The pivotal findings concerning those pathways undoubtedly contributed to the realization that yeast is a relevant model for understanding signal transduction in higher eukaryotes. Consequently, the last 25 years have witnessed the discovery of many signal transduction pathways in S. cerevisiae, including the high osmotic glycerol (Hog1), Stl2/Mpk1 and Smk1 mitogen-activated protein (MAP) kinase pathways, the TOR, AMPK/Snf1, SPS, PLC1 and Pkr/Gcn2 cascades, and systems that sense and respond to various types of stress. For many cascades, orthologous pathways were identified in mammals following their discovery in yeast. Here we review advances in the understanding of signaling in S. cerevisiae over the last 25 years. When all pathways are analyzed together, some prominent themes emerge. First, wiring of signaling cascades may not be identical in all S. cerevisiae strains, but is probably specific to each genetic background. This situation complicates attempts to decipher and generalize these webs of reactions. Secondly, the Ras/cAMP and the TOR cascades are pivotal pathways that affect all processes of the life of the yeast cell, whereas the yeast MAP kinase pathways are not essential. Yeast cells deficient in all MAP kinases proliferate normally. Another theme is the existence of central molecular hubs, either as single proteins (e.g., Msn2/4, Flo11) or as multisubunit complexes (e.g., TORC1/2), which are controlled by numerous pathways and in turn determine the fate of the cell. It is also apparent that lipid signaling is less developed in yeast than in higher eukaryotes. Finally, feedback regulatory mechanisms seem to be at least as important and powerful as the pathways themselves. In the final chapter of this essay we dare to imagine the essence of our next review on signaling in yeast, to be published on the 50th anniversary of Cellular Signalling in 2039.
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Affiliation(s)
- David Engelberg
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; CREATE-NUS-HUJ, Cellular & Molecular Mechanisms of Inflammation Programme, National University of Singapore, 1 CREATE Way, Innovation Wing, #03-09, Singapore 138602, Singapore.
| | - Riki Perlman
- Hematology Division, Hadassah Hebrew University Medical Center, POB 12000, 91120 Jerusalem, Israel
| | - Alexander Levitzki
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
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Mehrotra S, Galdieri L, Zhang T, Zhang M, Pemberton LF, Vancura A. Histone hypoacetylation-activated genes are repressed by acetyl-CoA- and chromatin-mediated mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:751-63. [PMID: 24907648 DOI: 10.1016/j.bbagrm.2014.05.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 05/12/2014] [Accepted: 05/29/2014] [Indexed: 01/07/2023]
Abstract
Transcriptional activation is typically associated with increased acetylation of promoter histones. However, this paradigm does not apply to transcriptional activation of all genes. In this study we have characterized a group of genes that are repressed by histone acetylation. These histone hypoacetylation-activated genes (HHAAG) are normally repressed during exponential growth, when the cellular level of acetyl-CoA is high and global histone acetylation is also high. The HHAAG are induced during diauxic shift, when the levels of acetyl-CoA and global histone acetylation decrease. The histone hypoacetylation-induced activation of HHAAG is independent of Msn2/Msn4. The repression of HSP12, one of the HHAAG, is associated with well-defined nucleosomal structure in the promoter region, while histone hypoacetylation-induced activation correlates with delocalization of positioned nucleosomes or with reduced nucleosome occupancy. Correspondingly, unlike the majority of yeast genes, HHAAG are transcriptionally upregulated when expression of histone genes is reduced. Taken together, these results suggest a model in which histone acetylation is required for proper positioning of promoter nucleosomes and repression of HHAAG.
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Affiliation(s)
- Swati Mehrotra
- Department of Biological Sciences, St. John's University, Queens, NY 11439, USA
| | - Luciano Galdieri
- Department of Biological Sciences, St. John's University, Queens, NY 11439, USA
| | - Tiantian Zhang
- Department of Biological Sciences, St. John's University, Queens, NY 11439, USA
| | - Man Zhang
- Department of Biological Sciences, St. John's University, Queens, NY 11439, USA
| | - Lucy F Pemberton
- Center for Cell Signalling, Department of Microbiology, University of Virginia Health Sciences Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Ales Vancura
- Department of Biological Sciences, St. John's University, Queens, NY 11439, USA.
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9
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Ye C, Bandara WMMS, Greenberg ML. Regulation of inositol metabolism is fine-tuned by inositol pyrophosphates in Saccharomyces cerevisiae. J Biol Chem 2013; 288:24898-908. [PMID: 23824185 PMCID: PMC3750184 DOI: 10.1074/jbc.m113.493353] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/01/2013] [Indexed: 01/10/2023] Open
Abstract
Although inositol pyrophosphates have diverse roles in phosphate signaling and other important cellular processes, little is known about their functions in the biosynthesis of inositol and phospholipids. Here, we show that KCS1, which encodes an inositol pyrophosphate kinase, is a regulator of inositol metabolism. Deletion of KCS1, which blocks synthesis of inositol pyrophosphates on the 5-hydroxyl of the inositol ring, causes inositol auxotrophy and decreased intracellular inositol and phosphatidylinositol. These defects are caused by a profound decrease in transcription of INO1, which encodes myo-inositol-3-phosphate synthase. Expression of genes that function in glycolysis, transcription, and protein processing is not affected in kcs1Δ. Deletion of OPI1, the INO1 transcription repressor, does not fully rescue INO1 expression in kcs1Δ. Both the inositol pyrophosphate kinase and the basic leucine zipper domains of KCS1 are required for INO1 expression. Kcs1 is regulated in response to inositol, as Kcs1 protein levels are increased in response to inositol depletion. The Kcs1-catalyzed production of inositol pyrophosphates from inositol pentakisphosphate but not inositol hexakisphosphate is indispensable for optimal INO1 transcription. We conclude that INO1 transcription is fine-tuned by the synthesis of inositol pyrophosphates, and we propose a model in which modulation of Kcs1 controls INO1 transcription by regulating synthesis of inositol pyrophosphates.
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Affiliation(s)
- Cunqi Ye
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - W. M. M. S. Bandara
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - Miriam L. Greenberg
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
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Galdieri L, Chang J, Mehrotra S, Vancura A. Yeast phospholipase C is required for normal acetyl-CoA homeostasis and global histone acetylation. J Biol Chem 2013; 288:27986-98. [PMID: 23913687 DOI: 10.1074/jbc.m113.492348] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Phospholipase C (Plc1p) is required for the initial step of inositol polyphosphate (InsP) synthesis, and yeast cells with deletion of the PLC1 gene are completely devoid of any InsPs and display aberrations in transcriptional regulation. Here we show that Plc1p is required for a normal level of histone acetylation; plc1Δ cells that do not synthesize any InsPs display decreased acetylation of bulk histones and global hypoacetylation of chromatin histones. In accordance with the role of Plc1p in supporting histone acetylation, plc1Δ mutation is synthetically lethal with mutations in several subunits of SAGA and NuA4 histone acetyltransferase (HAT) complexes. Conversely, the growth rate, sensitivity to multiple stresses, and the transcriptional defects of plc1Δ cells are partially suppressed by deletion of histone deacetylase HDA1. The histone hypoacetylation in plc1Δ cells is due to the defect in degradation of repressor Mth1p, and consequently lower expression of HXT genes and reduced conversion of glucose to acetyl-CoA, a substrate for HATs. The histone acetylation and transcriptional defects can be partially suppressed and the overall fitness improved in plc1Δ cells by increasing the cellular concentration of acetyl-CoA. Together, our data indicate that Plc1p and InsPs are required for normal acetyl-CoA homeostasis, which, in turn, regulates global histone acetylation.
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Affiliation(s)
- Luciano Galdieri
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
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11
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Galdieri L, Vancura A. Acetyl-CoA carboxylase regulates global histone acetylation. J Biol Chem 2012; 287:23865-76. [PMID: 22580297 PMCID: PMC3390662 DOI: 10.1074/jbc.m112.380519] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Indexed: 12/15/2022] Open
Abstract
Histone acetylation depends on intermediary metabolism for supplying acetyl-CoA in the nucleocytosolic compartment. However, because nucleocytosolic acetyl-CoA is also used for de novo synthesis of fatty acids, histone acetylation and synthesis of fatty acids compete for the same acetyl-CoA pool. The first and rate-limiting reaction in de novo synthesis of fatty acids is carboxylation of acetyl-CoA to form malonyl-CoA, catalyzed by acetyl-CoA carboxylase. In yeast Saccharomyces cerevisiae, acetyl-CoA carboxylase is encoded by the ACC1 gene. In this study, we show that attenuated expression of ACC1 results in increased acetylation of bulk histones, globally increased acetylation of chromatin histones, and altered transcriptional regulation. Together, our data indicate that Acc1p activity regulates the availability of acetyl-CoA for histone acetyltransferases, thus representing a link between intermediary metabolism and epigenetic mechanisms of transcriptional regulation.
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Affiliation(s)
- Luciano Galdieri
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
| | - Ales Vancura
- From the Department of Biological Sciences, St. John's University, Queens, New York 11439
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12
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Rupwate SD, Rupwate PS, Rajasekharan R. Regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C through the transcriptional repression of upstream activating sequence inositol containing genes. FEBS Lett 2012; 586:1555-60. [PMID: 22673525 DOI: 10.1016/j.febslet.2012.04.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 04/11/2012] [Accepted: 04/12/2012] [Indexed: 10/28/2022]
Abstract
The regulation of phospholipid biosynthesis in Saccharomyces cerevisiae through cis-acting upstream activating sequence inositol (UAS(ino)) and trans-acting elements, such as the INO2-INO4 complex and OPI1 by inositol supplementation in growth is thoroughly studied. In this study, we provide evidence for the regulation of lipid biosynthesis by phosphatidylinositol-specific phospholipase C (PLC) through UAS(ino) and the trans-acting elements. Gene expression analysis and radiolabelling experiments demonstrated that the overexpression of rice PLC in yeast cells altered phospholipid biosynthesis at the levels of transcriptional and enzyme activity. This is the first report implicating PLC in the direct regulation of lipid biosynthesis.
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Affiliation(s)
- Sunny D Rupwate
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
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13
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Borklu Yucel E, Ulgen KO. A network-based approach on elucidating the multi-faceted nature of chronological aging in S. cerevisiae. PLoS One 2011; 6:e29284. [PMID: 22216232 PMCID: PMC3244448 DOI: 10.1371/journal.pone.0029284] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 11/23/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Cellular mechanisms leading to aging and therefore increasing susceptibility to age-related diseases are a central topic of research since aging is the ultimate, yet not understood mechanism of the fate of a cell. Studies with model organisms have been conducted to ellucidate these mechanisms, and chronological aging of yeast has been extensively used as a model for oxidative stress and aging of postmitotic tissues in higher eukaryotes. METHODOLOGY/PRINCIPAL FINDINGS The chronological aging network of yeast was reconstructed by integrating protein-protein interaction data with gene ontology terms. The reconstructed network was then statistically "tuned" based on the betweenness centrality values of the nodes to compensate for the computer automated method. Both the originally reconstructed and tuned networks were subjected to topological and modular analyses. Finally, an ultimate "heart" network was obtained via pooling the step specific key proteins, which resulted from the decomposition of the linear paths depicting several signaling routes in the tuned network. CONCLUSIONS/SIGNIFICANCE The reconstructed networks are of scale-free and hierarchical nature, following a power law model with γ = 1.49. The results of modular and topological analyses verified that the tuning method was successful. The significantly enriched gene ontology terms of the modular analysis confirmed also that the multifactorial nature of chronological aging was captured by the tuned network. The interplay between various signaling pathways such as TOR, Akt/PKB and cAMP/Protein kinase A was summarized in the "heart" network originated from linear path analysis. The deletion of four genes, TCB3, SNA3, PST2 and YGR130C, was found to increase the chronological life span of yeast. The reconstructed networks can also give insight about the effect of other cellular machineries on chronological aging by targeting different signaling pathways in the linear path analysis, along with unraveling of novel proteins playing part in these pathways.
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Affiliation(s)
- Esra Borklu Yucel
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey.
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14
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Galdieri L, Desai P, Vancura A. Facilitated assembly of the preinitiation complex by separated tail and head/middle modules of the mediator. J Mol Biol 2011; 415:464-74. [PMID: 22137896 DOI: 10.1016/j.jmb.2011.11.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 11/09/2011] [Accepted: 11/10/2011] [Indexed: 02/06/2023]
Abstract
Mediator is a general coactivator of RNA polymerase II (RNA pol II) bridging enhancer-bound transcriptional factors with RNA pol II. Mediator is organized in three distinct subcomplexes: head, middle, and tail modules. The head and middle modules interact with RNA pol II, and the tail module interacts with transcriptional activators. Deletion of one of the tail subunits SIN4 results in derepression of a subset of genes, including FLR1, by a largely unknown mechanism. Here we show that derepression of FLR1 transcription in sin4Δ cells occurs by enhanced recruitment of the mediator as well as Swi/Snf and SAGA complexes. The tail and head/middle modules of the mediator behave as separate complexes at the induced FLR1 promoter. While the tail module remains anchored to the promoter, the head/middle modules are also found in the coding region. The separation of the tail and head/middle modules in sin4Δ cells is also supported by the altered stoichiometry of the tail and head/middle modules at several tested promoters. Deletion of another subunit of the tail module MED2 in sin4Δ cells results in significantly decreased transcription of FLR1, pointing to the importance of the integrity of the separated tail module in derepression. All tested genes exhibited increased recruitment of the tail domain; however, only genes with increased occupancy of the head/middle modules also displayed increased transcription. The separated tail module thus represents a promiscuous transcriptional factor that binds to many different promoters and is necessary for derepression of FLR1 in sin4Δ cells.
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Affiliation(s)
- Luciano Galdieri
- Department of Biological Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY 11439, USA
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15
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Glucose-induced calcium influx in budding yeast involves a novel calcium transport system and can activate calcineurin. Cell Calcium 2011; 49:376-86. [DOI: 10.1016/j.ceca.2011.03.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 02/15/2011] [Accepted: 03/17/2011] [Indexed: 11/16/2022]
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Genome-wide screen for inositol auxotrophy in Saccharomyces cerevisiae implicates lipid metabolism in stress response signaling. Mol Genet Genomics 2010; 285:125-49. [PMID: 21136082 DOI: 10.1007/s00438-010-0592-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 11/20/2010] [Indexed: 12/13/2022]
Abstract
Inositol auxotrophy (Ino(-) phenotype) in budding yeast has classically been associated with misregulation of INO1 and other genes involved in lipid metabolism. To identify all non-essential yeast genes that are necessary for growth in the absence of inositol, we carried out a genome-wide phenotypic screening for deletion mutants exhibiting Ino(-) phenotypes under one or more growth conditions. We report the identification of 419 genes, including 385 genes not previously reported, which exhibit this phenotype when deleted. The identified genes are involved in a wide range of cellular processes, but are particularly enriched in those affecting transcription, protein modification, membrane trafficking, diverse stress responses, and lipid metabolism. Among the Ino(-) mutants involved in stress response, many exhibited phenotypes that are strengthened at elevated temperature and/or when choline is present in the medium. The role of inositol in regulation of lipid metabolism and stress response signaling is discussed.
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Djordjevic JT. Role of phospholipases in fungal fitness, pathogenicity, and drug development - lessons from cryptococcus neoformans. Front Microbiol 2010; 1:125. [PMID: 21687772 PMCID: PMC3109512 DOI: 10.3389/fmicb.2010.00125] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/25/2010] [Indexed: 11/13/2022] Open
Abstract
Many pathogenic microbes, including many fungi, produce phospholipases which facilitate survival of the pathogen in vivo, invasion and dissemination throughout the host, expression of virulence traits and evasion of host immune defense mechanisms. These phospholipases are either secreted or produced intracellularly and act by physically disrupting host membranes, and/or by affecting fungal cell signaling and production of immunomodulatory effectors. Many of the secreted phospholipases acquire a glycosylphosphatidylinositol sorting motif to facilitate membrane and/or cell wall association and secretion. This review focuses primarily on the role of two members of the phospholipase enzyme family, phospholipase B (Plb) and phosphatidylinositol (PI)-specific phospholipase C (PI-C/Plc), in fungal pathogenesis and in particular, what has been learnt about their function from studies performed in the model pathogenic yeast, Cryptococcus neoformans. These studies have revealed how Plb has adapted to become an important part of the virulence repertoire of pathogenic fungi and how its secretion is regulated. They have also provided valuable insight into how the intracellular enzyme, Plc1, contributes to fungal fitness and pathogenicity – via a putative role in signal transduction pathways that regulate the production of stress-protecting pigments, polysaccharide capsule, cell wall integrity, and adaptation to growth at host temperature. Finally, this review will address the role fungal phospholipases have played in the development of a new class of antifungal drugs, which mimic their phospholipid substrates.
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Affiliation(s)
- Julianne Teresa Djordjevic
- Fungal Pathogenesis Laboratory, Centre for Infectious Diseases and Microbiology, Sydney Medical School-Western, Westmead Millennium Institute, University of Sydney at Westmead Hospital Westmead, NSW, Australia
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Guzinska K, Varghese R, Vancura A. Role of Plc1p in regulation of Mcm1p-dependent genes. FEMS Microbiol Lett 2009; 295:245-50. [PMID: 19459978 DOI: 10.1111/j.1574-6968.2009.01602.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
In budding yeasts, phosphoinositide-specific phospholipase C (Plc1p encoded by PLC1 gene) and several inositol polyphosphate kinases represent a nuclear pathway for synthesis of inositol polyphosphates (InsPs), which are involved in several aspects of DNA and RNA metabolism, including transcriptional regulation. Plc1p-produced inositol trisphosphate (InsP(3)) is phosphorylated by Ipk2p/Arg82p to yield InsP(4)/InsP(5). Ipk2p/Arg82p is also a component of ArgR-Mcm1p complex that regulates transcription of genes involved in arginine metabolism. The role of Ipk2p/Arg82p in this complex is to stabilize the essential MADS box protein Mcm1p. Consequently, ipk2Delta cells display reduced levels of Mcm1p and attenuated expression of Mcm1p-dependent genes. Because plc1Delta cells display aberrant expression of several groups of genes, including genes involved in stress response, the objective of this study was to determine whether Plc1p also affects expression of Mcm1p-dependent genes. Here we report that not only ipk2Delta, but also plc1Delta cells display decreased expression of Mcm1p-dependent genes. However, Plc1p is not involved in stabilization of Mcm1p and affects transcription of Mcm1p-dependent genes by a different mechanism, probably involving regulation of chromatin remodeling complexes.
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Affiliation(s)
- Katarzyna Guzinska
- Department of Biological Sciences, St John's University, Queens, NY 11439, USA
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Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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