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Hrach VL, King WR, Nelson LD, Conklin S, Pollock JA, Patton-Vogt J. The acyltransferase Gpc1 is both a target and an effector of the unfolded protein response in Saccharomyces cerevisiae. J Biol Chem 2023; 299:104884. [PMID: 37269946 PMCID: PMC10331479 DOI: 10.1016/j.jbc.2023.104884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 05/25/2023] [Accepted: 05/27/2023] [Indexed: 06/05/2023] Open
Abstract
The unfolded protein response (UPR) is sensitive to proteotoxic and membrane bilayer stress, both of which are sensed by the ER protein Ire1. When activated, Ire1 splices HAC1 mRNA, producing a transcription factor that targets genes involved in proteostasis and lipid metabolism, among others. The major membrane lipid phosphatidylcholine (PC) is subject to phospholipase-mediated deacylation, producing glycerophosphocholine (GPC), followed by reacylation of GPC through the PC deacylation/reacylation pathway (PC-DRP). The reacylation events occur via a two-step process catalyzed first by the GPC acyltransferase Gpc1, followed by acylation of the lyso-PC molecule by Ale1. However, whether Gpc1 is critical for ER bilayer homeostasis is unclear. Using an improved method for C14-choline-GPC radiolabeling, we first show that loss of Gpc1 results in abrogation of PC synthesis through PC-DRP and that Gpc1 colocalizes with the ER. We then probe the role of Gpc1 as both a target and an effector of the UPR. Exposure to the UPR-inducing compounds tunicamycin, DTT, and canavanine results in a Hac1-dependent increase in GPC1 message. Further, cells lacking Gpc1 exhibit increased sensitivity to those proteotoxic stressors. Inositol limitation, known to induce the UPR via bilayer stress, also induces GPC1 expression. Finally, we show that loss of GPC1 induces the UPR. A gpc1Δ mutant displays upregulation of the UPR in strains expressing a mutant form of Ire1 that is unresponsive to unfolded proteins, indicating that bilayer stress is responsible for the observed upregulation. Collectively, our data indicate an important role for Gpc1 in yeast ER bilayer homeostasis.
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Affiliation(s)
- Victoria Lee Hrach
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - William R King
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Laura D Nelson
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Shane Conklin
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - John A Pollock
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Jana Patton-Vogt
- Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania, USA.
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2
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FSH1 encodes lysophospholipase activity in Saccharomyces cerevisiae. Biotechnol Lett 2020; 43:279-286. [PMID: 32920715 DOI: 10.1007/s10529-020-03004-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/08/2020] [Indexed: 01/05/2023]
Abstract
OBJECTIVES To elucidate the role of FSH1 (family of serine hydrolase) in lipid homeostasis. RESULTS Proteins in various species containing alpha/beta hydrolase domain are known to be involved in lipid metabolism. In silico analysis of the FSH1 gene in Saccharomyces cerevisiae revealed the presence of alpha/beta hydrolase domain (ABHD) and a lipase motif (GXSXG), however its function in lipid metabolism remained elusive. The overexpression of FSH1 in WT and fsh1Δ cells showed a significant reduction in the cellular phospholipid levels and an increase in the triacylglycerol levels and lipid droplet (LD) number. Furthermore, the purified recombinant protein Fsh1p was identified as a lysophospholipase that specifically acts on lysophosphatidylserine (LPS) and impacts the lipid homeostasis in S. cerevisiae. CONCLUSIONS These results depicted that Fsh1p has a role on lipid homeostasis and is a lysophospholipase that hydrolyzes lysophosphatidylserine (LPS).
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3
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Kwiatek JM, Han GS, Carman GM. Phosphatidate-mediated regulation of lipid synthesis at the nuclear/endoplasmic reticulum membrane. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158434. [PMID: 30910690 PMCID: PMC6755077 DOI: 10.1016/j.bbalip.2019.03.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 03/14/2019] [Indexed: 12/11/2022]
Abstract
In yeast and higher eukaryotes, phospholipids and triacylglycerol are derived from phosphatidate at the nuclear/endoplasmic reticulum membrane. In de novo biosynthetic pathways, phosphatidate is channeled into membrane phospholipids via its conversion to CDP-diacylglycerol. Its dephosphorylation to diacylglycerol is required for the synthesis of triacylglycerol as well as for the synthesis of phosphatidylcholine and phosphatidylethanolamine via the Kennedy pathway. In addition to the role of phosphatidate as a precursor, it is a regulatory molecule in the transcriptional control of phospholipid synthesis genes via the Henry regulatory circuit. Pah1 phosphatidate phosphatase and Dgk1 diacylglycerol kinase are key players that function counteractively in the control of the phosphatidate level at the nuclear/endoplasmic reticulum membrane. Loss of Pah1 phosphatidate phosphatase activity not only affects triacylglycerol synthesis but also disturbs the balance of the phosphatidate level, resulting in the alteration of lipid synthesis and related cellular defects. The pah1Δ phenotypes requiring Dgk1 diacylglycerol kinase exemplify the importance of the phosphatidate level in the misregulation of cellular processes. The catalytic function of Pah1 requires its translocation from the cytoplasm to the nuclear/endoplasmic reticulum membrane, which is regulated through its phosphorylation in the cytoplasm by multiple protein kinases as well as through its dephosphorylation by the membrane-associated Nem1-Spo7 protein phosphatase complex. This article is part of a Special Issue entitled Endoplasmic reticulum platforms for lipid dynamics edited by Shamshad Cockcroft and Christopher Stefan.
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Affiliation(s)
- Joanna M Kwiatek
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901, USA
| | - Gil-Soo Han
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901, USA
| | - George M Carman
- Department of Food Science and the Rutgers Center for Lipid Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ 08901, USA.
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4
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Holič R, Pokorná L, Griač P. Metabolism of phospholipids in the yeast
Schizosaccharomyces pombe. Yeast 2019; 37:73-92. [DOI: 10.1002/yea.3451] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 12/28/2022] Open
Affiliation(s)
- Roman Holič
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
| | - Lucia Pokorná
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
| | - Peter Griač
- Centre of Biosciences, Slovak Academy of Sciences Institute of Animal Biochemistry and Genetics Dúbravská cesta 9 Bratislava Slovakia
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5
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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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6
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Renne MF, de Kroon AIPM. The role of phospholipid molecular species in determining the physical properties of yeast membranes. FEBS Lett 2017; 592:1330-1345. [PMID: 29265372 PMCID: PMC5947837 DOI: 10.1002/1873-3468.12944] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 11/27/2017] [Accepted: 12/11/2017] [Indexed: 12/18/2022]
Abstract
In most eukaryotes, including Saccharomyces cerevisiae, glycerophospholipids are the main membrane lipid constituents. Besides serving as general membrane ‘building blocks’, glycerophospholipids play an important role in determining the physical properties of the membrane, which are crucial for proper membrane function. To ensure optimal physical properties, membrane glycerophospholipid composition and synthesis are tightly regulated. This review will summarize our current knowledge of factors and processes determining the membrane glycerophospholipid composition of the reference eukaryote S. cerevisiae at the level of molecular species. Extrapolating from relevant model membrane data, we also discuss how modulation of the molecular species composition can regulate membrane physical properties.
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Affiliation(s)
- Mike F. Renne
- Membrane Biochemistry & BiophysicsDepartment of ChemistryBijvoet Center for Biomolecular Research & Institute of BiomembranesUtrecht Universitythe Netherlands
| | - Anton I. P. M. de Kroon
- Membrane Biochemistry & BiophysicsDepartment of ChemistryBijvoet Center for Biomolecular Research & Institute of BiomembranesUtrecht Universitythe Netherlands
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7
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Behera DK, Behera PM, Acharya L, Dixit A. Pharmacophore modelling, virtual screening and molecular docking studies on PLD1 inhibitors. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2017; 28:991-1009. [PMID: 29113495 DOI: 10.1080/1062936x.2017.1393774] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/15/2017] [Indexed: 06/07/2023]
Abstract
Lipid metabolism plays a significant role in influenza virus replication and subsequent infection. The regulatory mechanism governing lipid metabolism and viral replication is not properly understood to date, but both Phospholipase D (PLD1 and PLD2) activities are stimulated in viral infection. In vitro studies indicate that chemical inhibition of PLD1 delays viral entry and reduction of viral loads. The current study reports a three-dimensional pharmacophore model based on 35 known PLD1 inhibitors. A sub-set of 25 compounds was selected as the training set and the remaining 10 compounds were kept in the test set. One hundred and twelve pharmacophore models were generated; a six-featured pharmacophore model (AADDHR.57) with survival score (2.69) produced a statistically significant three-dimensional quantitative structure-activity relationship model with r2 = 0.97 (internal training set), r2 = 0.71 (internal test set) and Q2 = 0.64. The predictive power of the pharmacophore model was validated with an external test set (r2 = 0.73) and a systematic virtual screening work-flow was employed showing an enrichment factor of 23.68 at the top 2% of the dataset (active and decoys). Finally, the model was used for screening of the filtered PubChem database to fetch molecules which can be proposed as potential PLD1 inhibitors for blocking influenza infection.
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Affiliation(s)
- D K Behera
- a Centre for Biotechnology , Siksha O Anusandhan University , Bhubaneswar , Odisha , India
| | - P M Behera
- b Computational Biology and Bioinformatics Lab, Department of Translational Research and Technology Development , Institute of Life Sciences , Bhubaneswar , Odisha , India
| | - L Acharya
- a Centre for Biotechnology , Siksha O Anusandhan University , Bhubaneswar , Odisha , India
| | - A Dixit
- b Computational Biology and Bioinformatics Lab, Department of Translational Research and Technology Development , Institute of Life Sciences , Bhubaneswar , Odisha , India
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8
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Differential roles of three FgPLD genes in regulating development and pathogenicity in Fusarium graminearum. Fungal Genet Biol 2017; 109:46-52. [PMID: 29079075 DOI: 10.1016/j.fgb.2017.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 10/21/2017] [Accepted: 10/23/2017] [Indexed: 12/20/2022]
Abstract
Phospholipase D (PLD) is an important phospholipid hydrolase that plays critical roles in various biological processes in eukaryotic cells. However, little is known about its functions in plant pathogenic fungi. In this study, we identified three FgPLD genes in Fusarium graminearum that are homologous to the Saccharomyces cerevisiae Spo14 gene. We constructed deletion mutants of all three FgPLD genes using homologous recombination. Deletion of FgPLD1 (Δpld1), but not FgPLD2 or FgPLD3, affected hyphal growth, conidiation, and perithecium formation. The Δpld1 mutant showed reduced deoxynivalenol (DON) production and virulence in flowering wheat heads and corn silks. Furthermore, three FgPLD proteins have the same subcellular localization and localize to the cytoplasm in F. graminearum. Taken together, these results indicate that FgPLD1, but not FgPLD2 or FgPLD3, is important for hyphal growth, sexual or asexual reproduction, and plant infection.
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9
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Miner GE, Starr ML, Hurst LR, Fratti RA. Deleting the DAG kinase Dgk1 augments yeast vacuole fusion through increased Ypt7 activity and altered membrane fluidity. Traffic 2017; 18:315-329. [PMID: 28276191 DOI: 10.1111/tra.12479] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 12/20/2022]
Abstract
Diacylglycerol (DAG) is a fusogenic lipid that can be produced through phospholipase C activity on phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2 ], or through phosphatidic acid (PA) phosphatase activity. The fusion of Saccharomyces cerevisiae vacuoles requires DAG, PA and PI(4,5)P2 , and the production of these lipids is thought to provide temporally specific stoichiometries that are critical for each stage of fusion. Furthermore, DAG and PA can be interconverted by the DAG kinase Dgk1 and the PA phosphatase Pah1. Previously we found that pah1 Δ vacuoles were fragmented, blocked in SNARE priming and showed arrested endosomal maturation. In other pathways the effects of deleting PAH1 can be compensated for by additionally deleting DGK1 ; however, deleting both genes did not rescue the pah1 Δ vacuolar defects. Deleting DGK1 alone caused a marked increase in vacuole fusion that was attributed to elevated DAG levels. This was accompanied by a gain in resistance to the inhibitory effects of PA as well as inhibitors of Ypt7 activity. Together these data show that Dgk1 function can act as a negative regulator of vacuole fusion through the production of PA at the cost of depleting DAG and reducing Ypt7 activity.
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Affiliation(s)
- Gregory E Miner
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Matthew L Starr
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Logan R Hurst
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
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10
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Bean BDM, Davey M, Conibear E. Cargo selectivity of yeast sorting nexins. Traffic 2017; 18:110-122. [PMID: 27883263 DOI: 10.1111/tra.12459] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 01/09/2023]
Abstract
Sorting nexins are PX domain-containing proteins that bind phospholipids and often act in membrane trafficking where they help to select cargo. However, the functions and cargo specificities of many sorting nexins are unknown. Here, a high-throughput imaging screen was used to identify new sorting nexin cargo in the yeast Saccharomyces cerevisiae. Deletions of 9 different sorting nexins were screened for mislocalization of a set of green fluorescent protein (GFP)-tagged membrane proteins found at the plasma membrane, Golgi or endosomes. This identified 27 proteins that require 1 or more sorting nexins for their correct localization, 23 of which represent novel sorting nexin cargo. Nine hits whose sorting was dependent on Snx4, the sorting nexin-containing retromer complex, or both retromer and Snx3, were examined in detail to search for potential sorting motifs. We identified cytosolic domains of Ear1, Ymd8 and Ymr010w that conferred retromer-dependent sorting on a chimeric reporter and identified conserved residues required for this sorting in a functional assay. This work defined a consensus sequence for retromer and Snx3-dependent sorting.
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Affiliation(s)
- Björn D M Bean
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
| | - Michael Davey
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
| | - Elizabeth Conibear
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
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11
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Ramya V, Rajasekharan R. ATG15
encodes a phospholipase and is transcriptionally regulated by YAP1 in Saccharomyces cerevisiae. FEBS Lett 2016; 590:3155-67. [DOI: 10.1002/1873-3468.12369] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 01/23/2023]
Affiliation(s)
- Visvanathan Ramya
- Lipidomics Centre; Department of Lipid Science; Central Food Technological Research Institute; Council of Scientific and Industrial Research; Mysore Karnataka India
- Academy of Scientific and Innovative Research; Mysore Karnataka India
| | - Ram Rajasekharan
- Lipidomics Centre; Department of Lipid Science; Central Food Technological Research Institute; Council of Scientific and Industrial Research; Mysore Karnataka India
- Academy of Scientific and Innovative Research; Mysore Karnataka India
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12
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Surlow BA, Cooley BM, Needham PG, Brodsky JL, Patton-Vogt J. Loss of Ypk1, the yeast homolog to the human serum- and glucocorticoid-induced protein kinase, accelerates phospholipase B1-mediated phosphatidylcholine deacylation. J Biol Chem 2014; 289:31591-604. [PMID: 25258318 DOI: 10.1074/jbc.m114.581157] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Ypk1, the yeast homolog of the human serum- and glucocorticoid-induced kinase (Sgk1), affects diverse cellular activities, including sphingolipid homeostasis. We now report that Ypk1 also impacts the turnover of the major phospholipid, phosphatidylcholine (PC). Pulse-chase radiolabeling reveals that a ypk1Δ mutant exhibits increased PC deacylation and glycerophosphocholine production compared with wild type yeast. Deletion of PLB1, a gene encoding a B-type phospholipase that hydrolyzes PC, in a ypk1Δ mutant curtails the increased PC deacylation. In contrast to previous data, we find that Plb1 resides in the ER and in the medium. Consistent with a link between Ypk1 and Plb1, the levels of both Plb1 protein and PLB1 message are elevated in a ypk1Δ strain compared with wild type yeast. Furthermore, deletion of PLB1 in a ypk1Δ mutant exacerbates phenotypes associated with loss of YPK1, including slowed growth and sensitivity to cell wall perturbation, suggesting that increased Plb1 activity buffers against the loss of Ypk1. Because Plb1 lacks a consensus phosphorylation site for Ypk1, we probed other processes under the control of Ypk1 that might be linked to PC turnover. Inhibition of sphingolipid biosynthesis by the drug myriocin or through utilization of a lcb1-100 mutant results in increased PLB1 expression. Furthermore, we discovered that the increase in PLB1 expression observed upon inhibition of sphingolipid synthesis or loss of Ypk1 is under the control of the Crz1 transcription factor. Taken together, these results suggest a functional interaction between Ypk1 and Plb1 in which altered sphingolipid metabolism up-regulates PLB1 expression via Crz1.
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Affiliation(s)
- Beth A Surlow
- From the Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282 and
| | - Benjamin M Cooley
- From the Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282 and
| | - Patrick G Needham
- the Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Jeffrey L Brodsky
- the Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Jana Patton-Vogt
- From the Department of Biological Sciences, Duquesne University, Pittsburgh, Pennsylvania 15282 and
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13
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Kang DW, Choi KY, Min DS. Functional regulation of phospholipase D expression in cancer and inflammation. J Biol Chem 2014; 289:22575-22582. [PMID: 24990948 DOI: 10.1074/jbc.r114.569822] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Phospholipase D (PLD) regulates downstream effectors by generating phosphatidic acid. Growing links of dysregulation of PLD to human disease have spurred interest in therapeutics that target its function. Aberrant PLD expression has been identified in multiple facets of complex pathological states, including cancer and inflammatory diseases. Thus, it is important to understand how the signaling network of PLD expression is regulated and contributes to progression of these diseases. Interestingly, small molecule PLD inhibitors can suppress PLD expression as well as enzymatic activity of PLD and have been shown to be effective in pathological mice models, suggesting the potential for use of PLD inhibitors as therapeutics against cancer and inflammation. Here, we summarize recent scientific developments regarding the regulation of PLD expression and its role in cancer and inflammatory processes.
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Affiliation(s)
- Dong Woo Kang
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 609-735
| | - Kang-Yell Choi
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, and; Translational Research Center for Protein Function Control, Yonsei University, Seoul 120-749, Korea
| | - Do Sik Min
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 609-735,; Translational Research Center for Protein Function Control, Yonsei University, Seoul 120-749, Korea.
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14
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15
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Horvath SE, Daum G. Lipids of mitochondria. Prog Lipid Res 2013; 52:590-614. [PMID: 24007978 DOI: 10.1016/j.plipres.2013.07.002] [Citation(s) in RCA: 606] [Impact Index Per Article: 55.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 07/31/2013] [Indexed: 01/06/2023]
Abstract
A unique organelle for studying membrane biochemistry is the mitochondrion whose functionality depends on a coordinated supply of proteins and lipids. Mitochondria are capable of synthesizing several lipids autonomously such as phosphatidylglycerol, cardiolipin and in part phosphatidylethanolamine, phosphatidic acid and CDP-diacylglycerol. Other mitochondrial membrane lipids such as phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sterols and sphingolipids have to be imported. The mitochondrial lipid composition, the biosynthesis and the import of mitochondrial lipids as well as the regulation of these processes will be main issues of this review article. Furthermore, interactions of lipids and mitochondrial proteins which are highly important for various mitochondrial processes will be discussed. Malfunction or loss of enzymes involved in mitochondrial phospholipid biosynthesis lead to dysfunction of cell respiration, affect the assembly and stability of the mitochondrial protein import machinery and cause abnormal mitochondrial morphology or even lethality. Molecular aspects of these processes as well as diseases related to defects in the formation of mitochondrial membranes will be described.
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Affiliation(s)
- Susanne E Horvath
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, A-8010 Graz, Austria
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16
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Park M, Do E, Jung WH. Lipolytic enzymes involved in the virulence of human pathogenic fungi. MYCOBIOLOGY 2013; 41:67-72. [PMID: 23874127 PMCID: PMC3714442 DOI: 10.5941/myco.2013.41.2.67] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 06/08/2013] [Indexed: 06/02/2023]
Abstract
Pathogenic microbes secrete various enzymes with lipolytic activities to facilitate their survival within the host. Lipolytic enzymes include extracellular lipases and phospholipases, and several lines of evidence have suggested that these enzymes contribute to the virulence of pathogenic fungi. Candida albicans and Cryptococcus neoformans are the most commonly isolated human fungal pathogens, and several biochemical and molecular approaches have identified their extracellular lipolytic enzymes. The role of lipases and phospholipases in the virulence of C. albicans has been extensively studied, and these enzymes have been shown to contribute to C. albicans morphological transition, colonization, cytotoxicity, and penetration to the host. While not much is known about the lipases in C. neoformans, the roles of phospholipases in the dissemination of fungal cells in the host and in signaling pathways have been described. Lipolytic enzymes may also influence the survival of the lipophilic cutaneous pathogenic yeast Malassezia species within the host, and an unusually high number of lipase-coding genes may complement the lipid dependency of this fungus. This review briefly describes the current understanding of the lipolytic enzymes in major human fungal pathogens, namely C. albicans, C. neoformans, and Malassezia spp.
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Affiliation(s)
- Minji Park
- Department of Systems Biotechnology, Chung-Ang University, Anseong 456-756, Korea
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17
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De Smet CH, Cox R, Brouwers JF, de Kroon AIPM. Yeast cells accumulate excess endogenous palmitate in phosphatidylcholine by acyl chain remodeling involving the phospholipase B Plb1p. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1167-76. [PMID: 23501167 DOI: 10.1016/j.bbalip.2013.03.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 03/01/2013] [Accepted: 03/04/2013] [Indexed: 11/18/2022]
Abstract
In the yeast Saccharomyces cerevisiae, the molecular species profile of the major membrane glycerophospholipid phosphatidylcholine (PC) is determined by the molecular species-selectivity of the biosynthesis routes and by acyl chain remodeling. Overexpression of the glycerol-3-phosphate acyltransferase Sct1p was recently shown to induce a strong increase in the cellular content of palmitate (C16:0). Using stable isotope labeling and mass spectrometry, the present study shows that wild type yeast overexpressing Sct1p incorporates excess C16:0 into PC via the methylation of PE, the CDP-choline route, and post-synthetic acyl chain remodeling. Overexpression of Sct1p increased the extent of remodeling of PE-derived PC, providing a novel tool to perform mechanistic studies on PC acyl chain exchange. The exchange of acyl chains occurred at both the sn-1 and sn-2 positions of the glycerol backbone of PC, and required the phospholipase B Plb1p for optimal efficiency. Sct1p-catalyzed acyl chain exchange, the acyl-CoA binding protein Acb1p, the Plb1p homologue Plb2p, and the glycerophospholipid:triacylglycerol transacylase Lro1p were not required for PC remodeling. The results indicate that PC serves as a buffer for excess cellular C16:0.
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18
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Abstract
Due to its genetic tractability and increasing wealth of accessible data, the yeast Saccharomyces cerevisiae is a model system of choice for the study of the genetics, biochemistry, and cell biology of eukaryotic lipid metabolism. Glycerolipids (e.g., phospholipids and triacylglycerol) and their precursors are synthesized and metabolized by enzymes associated with the cytosol and membranous organelles, including endoplasmic reticulum, mitochondria, and lipid droplets. Genetic and biochemical analyses have revealed that glycerolipids play important roles in cell signaling, membrane trafficking, and anchoring of membrane proteins in addition to membrane structure. The expression of glycerolipid enzymes is controlled by a variety of conditions including growth stage and nutrient availability. Much of this regulation occurs at the transcriptional level and involves the Ino2–Ino4 activation complex and the Opi1 repressor, which interacts with Ino2 to attenuate transcriptional activation of UASINO-containing glycerolipid biosynthetic genes. Cellular levels of phosphatidic acid, precursor to all membrane phospholipids and the storage lipid triacylglycerol, regulates transcription of UASINO-containing genes by tethering Opi1 to the nuclear/endoplasmic reticulum membrane and controlling its translocation into the nucleus, a mechanism largely controlled by inositol availability. The transcriptional activator Zap1 controls the expression of some phospholipid synthesis genes in response to zinc availability. Regulatory mechanisms also include control of catalytic activity of glycerolipid enzymes by water-soluble precursors, products and lipids, and covalent modification of phosphorylation, while in vivo function of some enzymes is governed by their subcellular location. Genome-wide genetic analysis indicates coordinate regulation between glycerolipid metabolism and a broad spectrum of metabolic pathways.
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Selvy PE, Lavieri RR, Lindsley CW, Brown HA. Phospholipase D: enzymology, functionality, and chemical modulation. Chem Rev 2011; 111:6064-119. [PMID: 21936578 PMCID: PMC3233269 DOI: 10.1021/cr200296t] [Citation(s) in RCA: 267] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Paige E Selvy
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37064, USA
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20
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Abstract
The yeast Saccharomyces cerevisiae, with its full complement of organelles, synthesizes membrane phospholipids by pathways that are generally common to those found in higher eukaryotes. Phospholipid synthesis in yeast is regulated in response to a variety of growth conditions (e.g., inositol supplementation, zinc depletion, and growth stage) by a coordination of genetic (e.g., transcriptional activation and repression) and biochemical (e.g., activity modulation and localization) mechanisms. Phosphatidate (PA), whose cellular levels are controlled by the activities of key phospholipid synthesis enzymes, plays a central role in the transcriptional regulation of phospholipid synthesis genes. In addition to the regulation of gene expression, phosphorylation of key phospholipid synthesis catalytic and regulatory proteins controls the metabolism of phospholipid precursors and products.
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Affiliation(s)
- George M Carman
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901, USA.
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21
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Ray S, Chen Y, Ayoung J, Hanna R, Brazill D. Phospholipase D controls Dictyostelium development by regulating G protein signaling. Cell Signal 2010; 23:335-43. [PMID: 20950684 DOI: 10.1016/j.cellsig.2010.09.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 09/21/2010] [Accepted: 09/28/2010] [Indexed: 10/19/2022]
Abstract
Dictyostelium discoideum cells normally exist as individual amoebae, but will enter a period of multicellular development upon starvation. The initial stages of development involve the aggregation of individual cells, using cAMP as a chemoattractant. Chemotaxis is initiated when cAMP binds to its receptor, cAR1, and activates the associated G protein, Gα2βγ. However, chemotaxis will not occur unless there is a high density of starving cells present, as measured by high levels of the secreted quorum sensing molecule, CMF. We previously demonstrated that cells lacking PldB bypass the need for CMF and can aggregate at low cell density, whereas cells overexpressing pldB do not aggregate even at high cell density. Here, we found that PldB controlled both cAMP chemotaxis and cell sorting. PldB was also required by CMF to regulate G protein signaling. Specifically, CMF used PldB, to regulate the dissociation of Gα2 from Gβγ. Using fluorescence resonance energy transfer (FRET), we found that along with cAMP, CMF increased the dissociation of the G protein. In fact, CMF augmented the dissociation induced by cAMP. This augmentation was lost in cells lacking PldB. PldB appears to mediate the CMF signal through the production of phosphatidic acid, as exogenously added phosphatidic acid phenocopies overexpression of pldB. These results suggest that phospholipase D activity is required for CMF to alter the kinetics of cAMP-induced G protein signaling.
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Affiliation(s)
- Sibnath Ray
- Department of Biological Sciences, Hunter College, New York, New York 10065, USA
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22
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Harkins AL, Yuan G, London SD, Dolan JW. An oleate-stimulated, phosphatidylinositol 4,5-bisphosphate-independent phospholipase D in Schizosaccharomyces pombe. FEMS Yeast Res 2010; 10:717-26. [DOI: 10.1111/j.1567-1364.2010.00646.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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23
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Yakir-Tamang L, Gerst JE. Phosphoinositides, exocytosis and polarity in yeast: all about actin? Trends Cell Biol 2009; 19:677-84. [PMID: 19818626 DOI: 10.1016/j.tcb.2009.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Revised: 07/21/2009] [Accepted: 09/16/2009] [Indexed: 10/20/2022]
Abstract
Cell polarity is necessary for cell division, morphogenesis and motility in eukaryotes, and is determined by dynamic control of the cytoskeleton and secretory pathway to promote directional growth. In yeast, three essential and tightly-regulated processes orchestrate polarization and facilitate bud growth. These processes include phosphoinositide (PI) signaling, Rho GTPase regulation of the actin cytoskeleton, and exocytosis. As yet, the interplay between these different processes is unclear, and two main models (Spatial Landmark and Allosteric Local Activation) have been proposed for Rho GTPase control of polarization in yeast. Here, we summarize the inter-relationship between these growth processes and present a more unified model, the Exocytic Signal model, which proposes that exocytosis and actin regulation are fully integrated events mediated by PI signaling.
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Affiliation(s)
- Liat Yakir-Tamang
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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Zhang M, Zhang Y, Giblin EM, Taylor DC. Ectopic expression of Arabidopsis phospholipase A genes elucidates role of phospholipase Bs in S. cerevisiae cells. Open Microbiol J 2009; 3:136-45. [PMID: 19707290 PMCID: PMC2731109 DOI: 10.2174/1874285800903010136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 07/21/2009] [Accepted: 07/24/2009] [Indexed: 11/22/2022] Open
Abstract
In S. cerevisiae neither disruption of the phospholipase B triple knockout mutant (plb1plb2plb3; plb123) nor over-expression of phospholipase Bs (PLBs) result in a phenotype different from wild type. In performing experiments to characterize candidate plant phospholipase (PLA) genes, we found, surprisingly, that ectopic expression of either of two different A. thaliana PLA2 or PLA1 genes in the yeast plb123 mutant completely inhibited cell growth. We proposed that while PLBs might not be essential for growth and metabolism of yeast cells, they may play an important role in cell survival by metabolizing excess intracellular lysophospholipids. To test our hypothesis, we overexpressed a plant phospholipase A2 (PLA2) in both WT and plb123 cells, producing a pool of lysophosphatidylcholine (lysoPtdCho) in both transformants. In 14C acetate labeling experiments, WT cells were able to catabolize the resultant labeled lysoPtdCho, preventing accumulation, and the cells grew normally. In contrast, in the triple plb123 mutant PLA2 transformant, lysoPtDCho accumulated more than 4-fold to a toxic level, inhibiting cell growth. However, this growth inhibition was complemented by co-expression of either PLB1, PLB2 or PLB3 in the plb123 triple mutant already expressing the plant PLA2. Furthermore, in labeling experiments, the rescued cells exhibited a 60-75% reduction in 14C-lysoPtdCho build-up compared to plb123PLA2 cells. Our data provides conclusive evidence that yeast PLBs can metabolize intracellular lysoPtdCho produced by plant PLA2 overexpression in yeast. Our experiments indicate the utility of ectopic plant phospholipase A gene expression to characterize poorly-understood phospholipid metabolism mutants in yeast or other organisms.
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Affiliation(s)
- Meng Zhang
- National Research Council of Canada, Plant Biotechnology Institute, 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada
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Rappley I, Gitler AD, Selvy PE, LaVoie MJ, Levy BD, Brown HA, Lindquist S, Selkoe DJ. Evidence that alpha-synuclein does not inhibit phospholipase D. Biochemistry 2009; 48:1077-83. [PMID: 19146388 DOI: 10.1021/bi801871h] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alpha-synuclein (alphaSyn) is a small cytosolic protein of unknown function, which is highly enriched in the brain. It is genetically linked to Parkinson's disease (PD) in that missense mutations or multiplication of the gene encoding alphaSyn causes early onset familial PD. Furthermore, the neuropathological hallmarks of both sporadic and familial PD, Lewy bodies and Lewy neurites, contain insoluble aggregates of alphaSyn. Several studies have reported evidence that alphaSyn can inhibit phospholipase D (PLD), which hydrolyzes phosphatidylcholine to form phosphatidic acid and choline. Although various hypotheses exist regarding the roles of alphaSyn in health and disease, no other specific biochemical function for this protein has been reported to date. Because PLD inhibition could represent an important function of alphaSyn, we sought to extend existing reports on this interaction. Using purified proteins, we tested the ability of alphaSyn to inhibit PLD activity in cell-free assays. We also examined several cell lines and transfection conditions to assess whether alphaSyn inhibits endogenous or overexpressed PLD in cultured mammalian cells. In yeast, we extended our previous report of an interaction between alphaSyn and PLD-dependent phenotypes, for which PLD activity is absolutely necessary. Despite testing a range of experimental conditions, including those previously published, we observed no significant inhibition of PLD by alphaSyn in any of these systems. We propose that the previously reported effects of alphaSyn on PLD activity could be due to increased endoplasmic reticulum-related stress associated with alphaSyn overexpression in cells, but are not likely due to a specific and direct interaction between alphaSyn and PLD.
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Affiliation(s)
- Irit Rappley
- Department of Neurology, Harvard Medical School and Brigham & Women's Hospital, Boston, Massachusetts 02115, USA
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Dippe M, Ulbrich-Hofmann R. Substrate specificity in phospholipid transformations by plant phospholipase D isoenzymes. PHYTOCHEMISTRY 2009; 70:361-365. [PMID: 19251290 DOI: 10.1016/j.phytochem.2009.01.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 12/09/2008] [Accepted: 01/22/2009] [Indexed: 05/27/2023]
Abstract
Phospholipase D (PLD) catalyzes the hydrolysis and transesterification of glycerophospholipids at the terminal phosphodiester bond. In many plants, several isoforms of PLD have been identified without knowing their functional differences. In this paper, the specificities of two PLD isoenzymes from white cabbage (Brassica oleracea var. capitata) and two ones from opium poppy (Papaver somniferum L.), which were recombinantly produced in Escherichia coli, were compared in the hydrolysis of phospholipids with different head groups and in the transphosphatidylation of phosphatiylcholine with several acceptor alcohols. In a biphasic reaction system, consisting of buffer and diethyl ether, the highly homologous isoenzymes are able to hydrolyze phosphatidylcholine, -glycerol, -ethanolamine, -inositol and - with one exception - also phosphatidylserine but with different individual reaction rates. In transphosphatidylation of phosphatidylcholine, they show significant differences in the rates of head group exchange but with the same trend in the preference of acceptor alcohols (ethanolamine>glycerol>>l-serine). For l- and d-serine a stereoselectivity of PLD was observed. The results suggest a physiological relevance of the different hydrolytic and transphosphatidylation activities in plant PLD isoenzymes.
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Affiliation(s)
- Martin Dippe
- Institute of Biochemistry and Biotechnology, Martin-Luther University, Halle-Wittenberg, Kurt-Mothes-Str. 3, D-06099 Halle, Germany
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27
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Rolland SG, Bruel CA. Sulphur and nitrogen regulation of the protease-encoding ACP1 gene in the fungus Botrytis cinerea: correlation with a phospholipase D activity. MICROBIOLOGY-SGM 2008; 154:1464-1473. [PMID: 18451055 DOI: 10.1099/mic.0.2007/012005-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Sulphur and nitrogen catabolic repressions are regulations that have long been recognized in fungi, but whose molecular bases remain largely elusive. This paper shows that catabolic repression of a protease-encoding gene correlates with the modulation of a phosphatidylethanolamine (PE)-specific phospholipase D (PLD) activity in the pathogenic fungus Botrytis cinerea. Our results first demonstrate that the ACP1 gene is subject to sulphur catabolic repression, with sulphate and cysteine inhibiting its expression. Sulphate and cysteine also cause a decrease of the total cellular PLD activity and, reciprocally, the two PLD inhibitors AEBSF [4-(2-aminoethyl)benzenesulphonyl fluoride] and curcumin negatively affect ACP1 expression in vivo. Cysteine moreover inhibits the PE-specific PLD activity in cell extracts. ACP1 is regulated by nitrogen, but here we show that this regulation does not rely on the proximal AREA binding site in its promoter, and that glutamine does not play a particular role in the process. A decrease in the total cellular PLD activity is also observed when the cells are fed ammonia, but this effect is smaller than that produced by sulphur. RNA-interference experiments finally suggest that the enzyme responsible for the PE-specific PLD activity is encoded by a gene that does not belong to the known HKD gene family of PLDs.
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Affiliation(s)
- Stéphane G Rolland
- Génomique fonctionnelle des champignons pathogènes des plantes, UMR5240 Microbiologie, Adaptation et Pathogénie, Université Lyon 1, CNRS, Bayer CropScience, Université de Lyon, 14 Rue Pierre Baizet, 69263 Lyon Cedex 9, France
| | - Christophe A Bruel
- Génomique fonctionnelle des champignons pathogènes des plantes, UMR5240 Microbiologie, Adaptation et Pathogénie, Université Lyon 1, CNRS, Bayer CropScience, Université de Lyon, 14 Rue Pierre Baizet, 69263 Lyon Cedex 9, France
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28
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Rajakumari S, Grillitsch K, Daum G. Synthesis and turnover of non-polar lipids in yeast. Prog Lipid Res 2008; 47:157-71. [DOI: 10.1016/j.plipres.2008.01.001] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 01/08/2008] [Accepted: 01/09/2008] [Indexed: 11/25/2022]
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An upstream regulator and downstream target of phospholipase D1 activity during pheromone response inSaccharomyces cerevisiae. FEMS Yeast Res 2008; 8:237-44. [DOI: 10.1111/j.1567-1364.2007.00336.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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30
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Benghezal M, Roubaty C, Veepuri V, Knudsen J, Conzelmann A. SLC1 and SLC4 encode partially redundant acyl-coenzyme A 1-acylglycerol-3-phosphate O-acyltransferases of budding yeast. J Biol Chem 2007; 282:30845-55. [PMID: 17675291 DOI: 10.1074/jbc.m702719200] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphatidic acid is the intermediate, from which all glycerophospholipids are synthesized. In yeast, it is generated from lysophosphatidic acid, which is acylated by Slc1p, an sn-2-specific, acyl-coenzyme A-dependent 1-acylglycerol-3-phosphate O-acyltransferase. Deletion of SLC1 is not lethal and does not eliminate all microsomal 1-acylglycerol-3-phosphate O-acyltransferase activity, suggesting that an additional enzyme may exist. Here we show that SLC4 (Yor175c), a gene of hitherto unknown function, encodes a second 1-acyl-sn-glycerol-3-phosphate acyltransferase. SLC4 harbors a membrane-bound O-acyltransferase motif and down-regulation of SLC4 strongly reduces 1-acyl-sn-glycerol-3-phosphate acyltransferase activity in microsomes from slc1Delta cells. The simultaneous deletion of SLC1 and SLC4 is lethal. Mass spectrometric analysis of lipids from slc1Delta and slc4Delta cells demonstrates that in vivo Slc1p and Slc4p generate almost the same glycerophospholipid profile. Microsomes from slc1Delta and slc4Delta cells incubated with [14C]oleoyl-coenzyme A in the absence of lysophosphatidic acid and without CTP still incorporate the label into glycerophospholipids, indicating that Slc1p and Slc4p can also use endogenous lysoglycerophospholipids as substrates. However, the lipid profiles generated by microsomes from slc1Delta and slc4Delta cells are different, and this suggests that Slc1p and Slc4p have a different substrate specificity or have access to different lyso-glycerophospholipid substrates because of a different subcellular location. Indeed, affinity-purified Slc1p displays Mg2+-dependent acyltransferase activity not only toward lysophosphatidic acid but also lyso forms of phosphatidylserine and phosphatidylinositol. Thus, Slc1p and Slc4p may not only be active as 1-acylglycerol-3-phosphate O-acyltransferases but also be involved in fatty acid exchange at the sn-2-position of mature glycerophospholipids.
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Affiliation(s)
- Mohammed Benghezal
- Department of Medicine, University of Fribourg, CH-1700 Fribourg, Switzerland
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31
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Gomez-Cambronero J, Di Fulvio M, Knapek K. Understanding phospholipase D (PLD) using leukocytes: PLD involvement in cell adhesion and chemotaxis. J Leukoc Biol 2007; 82:272-81. [PMID: 17431093 DOI: 10.1189/jlb.0107033] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Phospholipase D (PLD) is an enzyme that catalyzes the conversion of membrane phosphatidylcholine to choline and phosphatidic acid (PA; a second messenger). PLD is expressed in nearly all types of leukocytes and has been associated with phagocytosis, degranulation, microbial killing, and leukocyte maturation. With the application of recently developed molecular tools (i.e., expression vectors, silencing RNA, and specific antibodies), the demonstration of a key role for PLD in those and related cellular actions has contributed to a better awareness of its importance. A case in point is the recent findings that RNA interference-mediated depletion of PLD results in impaired leukocyte adhesion and chemotaxis toward a gradient of chemokines, implying that PLD is necessary for leukocyte movement. We forecast that based on results such as those, leukocytes may prove to be useful tools to unravel still-unresolved mechanistic issues in the complex biology of PLD. Three such issues are considered here: first, whether the cellular actions of PLD are mediated entirely by PA (the product of its enzymatic reaction) or whether PLD by itself interacts with other protein signaling molecules; second, the current difficulty of defining a "PA consensus site" in the various intracellular protein targets of PA; and third, the resolution of specific PLD location (upstream or downstream) in a particular effector signaling cascade. There are reasons to expect that leukocytes and their leukemic cell line counterparts will continue yielding invaluable information to cell biologists to resolve standing molecular and functional issues concerning PLD.
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Affiliation(s)
- Julian Gomez-Cambronero
- Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
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Strahl T, Thorner J. Synthesis and function of membrane phosphoinositides in budding yeast, Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1771:353-404. [PMID: 17382260 PMCID: PMC1868553 DOI: 10.1016/j.bbalip.2007.01.015] [Citation(s) in RCA: 231] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 01/29/2007] [Accepted: 01/30/2007] [Indexed: 02/02/2023]
Abstract
It is now well appreciated that derivatives of phosphatidylinositol (PtdIns) are key regulators of many cellular processes in eukaryotes. Of particular interest are phosphoinositides (mono- and polyphosphorylated adducts to the inositol ring in PtdIns), which are located at the cytoplasmic face of cellular membranes. Phosphoinositides serve both a structural and a signaling role via their recruitment of proteins that contain phosphoinositide-binding domains. Phosphoinositides also have a role as precursors of several types of second messengers for certain intracellular signaling pathways. Realization of the importance of phosphoinositides has brought increased attention to characterization of the enzymes that regulate their synthesis, interconversion, and turnover. Here we review the current state of our knowledge about the properties and regulation of the ATP-dependent lipid kinases responsible for synthesis of phosphoinositides and also the additional temporal and spatial controls exerted by the phosphatases and a phospholipase that act on phosphoinositides in yeast.
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Affiliation(s)
- Thomas Strahl
- Divisions of Biochemistry & Molecular Biology and of Cell & Developmental Biology.Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 USA
| | - Jeremy Thorner
- Divisions of Biochemistry & Molecular Biology and of Cell & Developmental Biology.Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 USA
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Uesugi Y, Arima J, Iwabuchi M, Hatanaka T. C-terminal loop of Streptomyces phospholipase D has multiple functional roles. Protein Sci 2006; 16:197-207. [PMID: 17189478 PMCID: PMC2203283 DOI: 10.1110/ps.062537907] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have recently shown that two flexible loops of Streptomyces phospholipase D (PLD) affect the catalytic reaction of the enzyme by a comparative study of chimeric PLDs. Gly188 and Asp191 of PLD from Streptomyces septatus TH-2 (TH-2PLD) were identified as the key amino acid residues involved in the recognition of phospholipids. In the present study, we further investigated the relationship between a C-terminal loop of TH-2PLD and PLD activities to elucidate the reaction mechanism and the recognition of the substrate. By analyzing chimeras and mutants in terms of hydrolytic and transphosphatidylation activities, Ala426 and Lys438 of TH-2PLD were identified as the residues associated with the activities. We found that Gly188 and Asp191 recognized substrate forms, whereas residues Ala426 and Lys438 enhanced transphosphatidylation and hydrolysis activities regardless of the substrate form. By substituting Ala426 and Lys438 with Phe and His, respectively, the mutant showed not only higher activities but also higher thermostability and tolerance against organic solvents. Furthermore, the mutant also improved the selectivity of the transphosphatidylation activity. The residues Ala426 and Lys438 were located in the C-terminal flexible loop of Streptomyces PLD separate from the highly conserved catalytic HxKxxxxD motifs. We demonstrated that this C-terminal loop, which formed the entrance of the active well, has multiple functional roles in Streptomyces PLD.
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Affiliation(s)
- Yoshiko Uesugi
- Research Institute for Biological Sciences-Okayama, 7549-1 Kibichuo-cho, Kaga-gun, Okayama 716-1241, Japan
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Lamour KH, Finley L, Hurtado-Gonzales O, Gobena D, Tierney M, Meijer HJG. Targeted gene mutation in Phytophthora spp. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2006; 19:1359-67. [PMID: 17153920 DOI: 10.1094/mpmi-19-1359] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The genus Phytophthora belongs to the oomycetes and is composed of plant pathogens. Currently, there are no strategies to mutate specific genes for members of this genus. Whole genome sequences are available or being prepared for Phytophthora sojae, P. ramorum, P. infestans, and P. capsici and the development of molecular biological techniques for functional genomics is encouraged. This article describes the adaptation of the reverse-genetic strategy of targeting induced local lesions in genomes (TILLING) to isolate gene-specific mutants in Phytophthora spp. A genomic library of 2,400 ethylnitrosourea (ENU) mutants of P. sojae was created and screened for induced point mutations in the genes encoding a necrosisinducing protein (PsojNIP) and a Phytophthora-specific phospholipase D (PsPXTM-PLD). Mutations were detected in single individuals and included silent, missense, and nonsense changes. Homozygous mutant isolates carrying a potentially deleterious missense mutation in PsojNIP and a premature stop codon in PsPXTM-PLD were identified. No phenotypic effect has yet been found for the homozygous mutant of PsojNIP. For those of PsPXTM-PLD, a reduction in growth rate and an appressed mycelial growth was observed. This demonstrates the feasibility of target-selected gene disruption for Phytophthora spp. and adds an important tool for functional genomic investigation.
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Affiliation(s)
- Kurt H Lamour
- Department of Entomology and Plant Pathology, The University of Tennessee, Rm 205 Ellington Plant Science, 2431 Joe Johnson Dr., Knoxville 37996, USA.
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35
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de Kroon AIPM. Metabolism of phosphatidylcholine and its implications for lipid acyl chain composition in Saccharomyces cerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1771:343-52. [PMID: 17010666 DOI: 10.1016/j.bbalip.2006.07.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 07/28/2006] [Accepted: 07/31/2006] [Indexed: 11/29/2022]
Abstract
Phosphatidylcholine (PC) is a very abundant membrane lipid in most eukaryotes including the model organism Saccharomyces cerevisiae. Consequently, the molecular species profile of PC, i.e. the ensemble of PC molecules with acyl chains differing in number of carbon atoms and double bonds, is important in determining the physical properties of eukaryotic membranes, and should be tightly regulated. In this review current insights in the contributions of biosynthesis, turnover, and remodeling by acyl chain exchange to the maintenance of PC homeostasis at the level of the molecular species in yeast are summarized. In addition, the phospholipid class-specific changes in membrane acyl chain composition induced by PC depletion are discussed, which identify PC as key player in a novel regulatory mechanism balancing the proportions of bilayer and non-bilayer lipids in yeast.
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Affiliation(s)
- Anton I P M de Kroon
- Department Biochemistry of Membranes, Bijvoet Institute and Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
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36
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Carman GM, Han GS. Regulation of phospholipid synthesis in Saccharomyces cerevisiae by zinc depletion. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1771:322-30. [PMID: 16807089 PMCID: PMC1876696 DOI: 10.1016/j.bbalip.2006.05.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 05/10/2006] [Accepted: 05/10/2006] [Indexed: 11/20/2022]
Abstract
The synthesis of phospholipids in the yeast Saccharomyces cerevisiae is regulated by zinc, an essential mineral required for growth and metabolism. Cells depleted of zinc contain increased levels of phosphatidylinositol and decreased levels of phosphatidylethanolamine. In addition to the major phospholipids, the levels of the minor phospholipids phosphatidate and diacylglycerol pyrophosphate decrease in the vacuole membrane of zinc-depleted cells. Alterations in phosphatidylinositol and phosphatidylethanolamine can be ascribed to an increase in PIS1-encoded phosphatidylinositol synthase activity and to decreases in the activities of CDP-diacylglycerol pathway enzymes including the CHO1-encoded phosphatidylserine synthase, respectively. Alterations in the minor vacuole membrane phospholipids are due to the induction of the DPP1-encoded diacylglycerol pyrophosphate phosphatase. These changes in the activities of phospholipid biosynthetic enzymes result from differential regulation of gene expression at the level of transcription. Under zinc-deplete conditions, the positive transcription factor Zap1p stimulates the expression of the DPP1 and PIS1 genes through the cis-acting element UAS(ZRE). In contrast, the negative regulatory protein Opi1p, which is involved in inositol-mediated regulation of phospholipid synthesis, represses the expression of the CHO1 gene through the cis-acting element UAS(INO). Regulation of phospholipid synthesis may provide an important mechanism by which cells cope with the stress of zinc depletion, given the roles that phospholipids play in the structure and function of cellular membranes.
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Affiliation(s)
- George M Carman
- Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, USA.
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Connolly JE, Engebrecht J. The Arf-GTPase-activating protein Gcs1p is essential for sporulation and regulates the phospholipase D Spo14p. EUKARYOTIC CELL 2006; 5:112-24. [PMID: 16400173 PMCID: PMC1360266 DOI: 10.1128/ec.5.1.112-124.2006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
SPO14, encoding the major Saccharomyces cerevisiae phospholipase D (PLD), is essential for sporulation and mediates synthesis of the new membrane that encompasses the haploid nuclei that arise through meiotic divisions. PLD catalyzes the hydrolysis of phosphatidylcholine to phosphatidic acid (PA) and choline. PA stimulates Arf-GTPase-activating proteins (Arf-GAPs), which are involved in membrane trafficking events and actin cytoskeletal function. To determine if Spo14p-generated PA mediates its biological response through Arf-GAPs, we analyzed the sporulation efficiencies of cells deleted for each of the five known and potential yeast Arf-GAPs. Only gcs1delta mutants display a sporulation defect similar to that of spo14 mutants: cells deleted for GCS1 initiate the sporulation program but are defective in synthesis of the prospore membrane. Endosome-to-vacuole transport is also impaired in gcs1delta cells during sporulation. Furthermore, Arf-GAP catalytic activity, but not the pleckstrin homology domain, is required for both prospore membrane formation and endosome-to-vacuole trafficking. An examination of Gcs1p-green fluorescent protein revealed that it is a soluble protein. Interestingly, cells deleted for GCS1 have reduced levels of Spo14p-generated PA. Taken together, these results indicate that GCS1 is essential for sporulation and suggest that GCS1 positively regulates SPO14.
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Affiliation(s)
- Jaime E Connolly
- Molecular and Cellular Pharmacology, Graduate Program, State University of New York at Stony Brook, 11794-8651, USA
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Guo BZ, Xu G, Cao YG, Holbrook CC, Lynch RE. Identification and characterization of phospholipase D and its association with drought susceptibilities in peanut (Arachis hypogaea). PLANTA 2006; 223:512-20. [PMID: 16200410 DOI: 10.1007/s00425-005-0112-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Accepted: 08/08/2005] [Indexed: 05/04/2023]
Abstract
Preharvest aflatoxin contamination has been identified by the peanut industry as a serious issue in food safety and human health because of the carcinogenic toxicity. Drought stress is the most important environmental factor exacerbating Aspergillus infection and aflatoxin contamination in peanut. The development of drought-tolerant peanut cultivars could reduce aflatoxin contamination and would represent a major advance in the peanut industry. In this study, we identified a novel PLD gene in peanut (Arachis hypogaea), encoding a putative phospholipase D (PLD, EC 3.1.4.4). The completed cDNA sequence was obtained by using the consensus-degenerated hybrid oligonucleotide primer strategy. The deduced amino acid sequence shows high identity with known PLDs, and has similar conserved domains. The PLD gene expression under drought stress has been studied using four peanut lines: Tifton 8 and A13 (both drought tolerant) and Georgia Green (moderate) and PI 196754 (drought sensitive). Northern analysis showed that PLD gene expression was induced faster by drought stress in the drought-sensitive lines than the drought tolerance lines. Southern analysis showed that cultivated peanut has multiple copies (3 to 5 copies) of the PLD gene. These results suggest that peanut PLD may be involved in drought sensitivity and tolerance responses. Peanut PLD gene expression may be useful as a tool in germplasm screening for drought tolerance.
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Affiliation(s)
- B Z Guo
- USDA-ARS, Crop Protection and Management Research Unit, Tifton, GA 31793, USA.
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Boumann HA, Gubbens J, Koorengevel MC, Oh CS, Martin CE, Heck AJR, Patton-Vogt J, Henry SA, de Kruijff B, de Kroon AIPM. Depletion of phosphatidylcholine in yeast induces shortening and increased saturation of the lipid acyl chains: evidence for regulation of intrinsic membrane curvature in a eukaryote. Mol Biol Cell 2005; 17:1006-17. [PMID: 16339082 PMCID: PMC1356607 DOI: 10.1091/mbc.e05-04-0344] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
To study the consequences of depleting the major membrane phospholipid phosphatidylcholine (PC), exponentially growing cells of a yeast cho2opi3 double deletion mutant were transferred from medium containing choline to choline-free medium. Cell growth did not cease until the PC level had dropped below 2% of total phospholipids after four to five generations. Increasing contents of phosphatidylethanolamine (PE) and phosphatidylinositol made up for the loss of PC. During PC depletion, the remaining PC was subject to acyl chain remodeling with monounsaturated species replacing diunsaturated species, as shown by mass spectrometry. The remodeling of PC did not require turnover by the SPO14-encoded phospholipase D. The changes in the PC species profile were found to reflect an overall shift in the cellular acyl chain composition that exhibited a 40% increase in the ratio of C16 over C18 acyl chains, and a 10% increase in the degree of saturation. The shift was stronger in the phospholipid than in the neutral lipid fraction and strongest in the species profile of PE. The shortening and increased saturation of the PE acyl chains were shown to decrease the nonbilayer propensity of PE. The results point to a regulatory mechanism in yeast that maintains intrinsic membrane curvature in an optimal range.
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Affiliation(s)
- Henry A Boumann
- Department of Biochemistry of Membranes, Bijvoet Institute, Utrecht University, 3584 CH Utrecht, The Netherlands
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Merkel O, Oskolkova O, Raab F, El-Toukhy R, Paltauf F. Regulation of activity in vitro and in vivo of three phospholipases B from Saccharomyces cerevisiae. Biochem J 2005; 387:489-96. [PMID: 15588231 PMCID: PMC1134978 DOI: 10.1042/bj20041272] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The genome of the yeast, Saccharomyces cerevisiae, contains three highly similar genes coding for phospholipases B/lysophospholipases. These enzymes behave differently with respect to substrate preferences in vitro and relative contributions to phospholipid catabolism in vivo [Merkel, Fido, Mayr, Pruger, Raab, Zandonella, Kohlwein and Paltauf (1999) J. Biol. Chem. 274, 28121-28127]. It is shown in the present study that, in vitro, pH markedly affects the substrate preference of Plb1p and Plb2p, but not of Plb3p. At the pH optimum of 2.5-3.5, the order of substrate preference of Plb1p and Plb2p is PtdSer (phosphatidylserine)>PtdIns>PtdCho (phosphatidylcholine>PtdEtn (phosphatidylethanolamine). At pH values of 5 and above, the substrate preferences change to PtdCho=PtdEtn for Plb1p and PtdSer=PtdEtn for Plb2p. Accordingly, with cultured cells the ratio of PtdIns/PtdCho breakdown, as reflected in the ratio of GroPIns (glycerophosphoinositol)/GroPCho (glycerophosphocholine) released into the culture medium, is inversely related to the pH of the growth medium. This effect is ascribed to the pH response of Plb1p, because Plb2p does not contribute to the degradation of PtdIns and PtdCho in vivo. Bivalent and tervalent cations activate phospholipases B at pH 5.5, but are inhibitory at pH 2.5. Al3+ at a concentration of 20 mM increases Plb1p activity in vitro by 8-fold and leads to a 9-fold increase in GroPCho release by whole cells. In vivo, cycloheximide strongly inhibits the breakdown of PtdIns, and to a lesser extent PtdCho. However, Al3+-stimulated GroPCho release is almost completely inhibited by cycloheximide. Deletion of PLB3 leads to increased sensitivity to toxic Al3+. Addition of SDS or melittin to cultured cells leads to a significant increase in phospholipid degradation, which is insensitive to inhibition by cycloheximide. Deletion mutants defective in the PLB1 gene are significantly more resistant to SDS than are wild-type cells.
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Affiliation(s)
- Olaf Merkel
- Institut für Biochemie, Technische Universität Graz, Petersgasse 12, 8010 Graz, Austria
- To whom correspondence should be sent, at present address: Institute of Molecular Biosciences, Universität Graz, Schubertstrasse 1, 8010 Graz, Austria (email or )
| | - Olga V. Oskolkova
- Institut für Biochemie, Technische Universität Graz, Petersgasse 12, 8010 Graz, Austria
| | - Florian Raab
- Institut für Biochemie, Technische Universität Graz, Petersgasse 12, 8010 Graz, Austria
| | - Rosemarie El-Toukhy
- Institut für Biochemie, Technische Universität Graz, Petersgasse 12, 8010 Graz, Austria
| | - Fritz Paltauf
- Institut für Biochemie, Technische Universität Graz, Petersgasse 12, 8010 Graz, Austria
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Hong S, Horiuchi H, Ohta A. Identification and molecular cloning of a gene encoding Phospholipase A2 (plaA) from Aspergillus nidulans. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1735:222-9. [PMID: 16051517 DOI: 10.1016/j.bbalip.2005.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Revised: 06/14/2005] [Accepted: 06/17/2005] [Indexed: 11/16/2022]
Abstract
The plaA gene encoding a protein that contains the cytosolic Phospholipase A(2) (cPLA(2)) motif is cloned for the first time from the filamentous fungus, Aspergillus nidulans. The translated 837 amino acid protein product of plaA comprises conserved lipase regions that are present in most mammalian cPLA(2) homologs. High expression of plaA was observed in glucose-lactose medium by Northern blot analyses. Deletion mutants of plaA grew and formed conidia similar to the wild-type strain, but showed decreased PLA(2) activity. Expression of the N-terminal truncated form of plaA in yeast cells resulted in increased Ca(2+)-dependent PLA(2) activity with (14)C-labeled phosphatidylcholine (PC) and phosphatidylethanolamine (PE) as substrates, compared with vector-transformed cells. In conclusion, we have identified and cloned a phospholipid-hydrolyzing novel cPLA(2) protein from A. nidulans for the first time.
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Affiliation(s)
- SaHyun Hong
- Department of Biotechnology, The University of Tokyo, Japan.
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Horn J, Lopez I, Miller M, Gomez-Cambronero J. The uncovering of a novel regulatory mechanism for PLD2: formation of a ternary complex with protein tyrosine phosphatase PTP1B and growth factor receptor-bound protein GRB2. Biochem Biophys Res Commun 2005; 332:58-67. [PMID: 15896299 PMCID: PMC3073396 DOI: 10.1016/j.bbrc.2005.04.093] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Accepted: 04/13/2005] [Indexed: 11/18/2022]
Abstract
The regulation of PLD2 activation is poorly understood at present. Transient transfection of COS-7 with a mycPLD2 construct results in elevated levels of PLD2 enzymatic activity and tyrosyl phosphorylation. To investigate whether this phosphorylation affects PLD2 enzymatic activity, anti-myc immunoprecipitates were treated with recombinant protein tyrosine phosphatase PTP1B. Surprisingly, lipase activity and PY levels both increased over a range of PTP1B concentrations. These increases occurred in parallel to a measurable PTP1B-associated phosphatase activity. Inhibitor studies demonstrated that an EGF-receptor type kinase is involved in phosphorylation. In a COS-7 cell line created in the laboratory that stably expressed myc-PLD2, PTP1B induced a robust (>6-fold) augmentation of myc-PLD2 phosphotyrosine content. The addition of growth factor receptor-bound protein 2 (Grb2) to cell extracts also elevated PY levels of myc-PLD (>10-fold). Systematic co-immunoprecipitation-immunoblotting experiments pointed at a physical association between PLD2, Grb2, and PTP1B in both physiological conditions and in overexpressed cells. This is the first report of a demonstration of the mammalian isoform PLD2 existing in a ternary complex with a protein tyrosine phosphatase, PTP1b, and the docking protein Grb2 which greatly enhances tyrosyl phosphorylation of the lipase.
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Affiliation(s)
- Jeff Horn
- Department of Physiology and Biophysics, Wright State University School of Medicine, Dayton, Ohio 45435
| | - Isabel Lopez
- Department of Pharmacology, The University of Illinois at Chicago, Illinois 60612
| | - Mill Miller
- Department of Biological Sciences, Wright State University, Dayton, Ohio 45435
| | - Julian Gomez-Cambronero
- Department of Physiology and Biophysics, Wright State University School of Medicine, Dayton, Ohio 45435
- Corresponding author: Julian Gomez-Cambronero, Ph.D., Department of Physiology & Biophysics, Wright State University School of Medicine, 3640 Colonel Glenn Highway, Dayton, OH 45435, Phone: (937) 775-3601, Fax: (937) 775-3391,
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43
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Merkel O, Schmid PC, Paltauf F, Schmid HHO. Presence and potential signaling function of N-acylethanolamines and their phospholipid precursors in the yeast Saccharomyces cerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1734:215-9. [PMID: 15878693 DOI: 10.1016/j.bbalip.2005.03.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 03/17/2005] [Accepted: 03/21/2005] [Indexed: 11/19/2022]
Abstract
N-acylethanolamines (NAEs) and N-acylphosphatidylethanolamines (NAPEs) are trace constituents of vertebrate cells and tissues and much is known about their metabolism and possible function in animals. Here we report for the first time the identification and quantification of NAEs and NAPEs in several strains of the yeast Saccharomyces cerevisiae. Gas chromatography-mass spectrometry of appropriate derivatives revealed 16:0, 16:1, 18:0 and 18:1 N-acyl groups in both NAE and NAPE whose levels, in wild-type cells, were 50 to 90 and 85 to 750 pmol/micromol lipid P, respectively (depending on the phase of growth). NAPE levels were reduced by 45 to 60% in a strain lacking three type B phospholipases, suggesting their involvement in NAPE synthesis by their known transacylation activity. A yeast strain lacking the YPL103c gene, which codes for a protein with 50.3% homology to human NAPE-specific phospholipase D, exhibited a 60% reduction in NAE, compared to wild-type controls. The exposure of various yeast strains to peroxidative stress, by incubation in media containing 0.6 mM H(2)O(2), resulted in substantial increases in NAE. Because yeast cells lack polyunsaturated fatty acids, they offer a useful system for the study of NAE generation and its potential signaling and cytoprotective effects in the absence of polyunsaturated ("endocannabinoid") congeners.
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Affiliation(s)
- Olaf Merkel
- Institute for Molecular Biosciences, University of Graz, A-8010 Graz, Austria
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Deng L, Sugiura R, Ohta K, Tada K, Suzuki M, Hirata M, Nakamura SI, Shuntoh H, Kuno T. Phosphatidylinositol-4-phosphate 5-kinase regulates fission yeast cell integrity through a phospholipase C-mediated protein kinase C-independent pathway. J Biol Chem 2005; 280:27561-8. [PMID: 15923187 DOI: 10.1074/jbc.m502660200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fission yeast its3-1 mutant is an allele of the essential gene its3+ that encodes a phosphatidylinositol-4-phosphate 5-kinase (PIP5K) that produces phosphatidylinositol 4,5-bisphosphate. We found that the its3-1 mutant is sensitive to micafungin, a (1,3)-beta-D-glucan synthase inhibitor, suggesting a cell wall integrity defect. Consistently, its3-1 mutation caused synthetic lethality with a (1,3)-beta-D-glucan synthase mutant, bgs1-i2, and its3-1 mutant cells showed aberrant localization of green fluorescent protein-Bgs1. Similar aberrant localization of green fluorescent protein-tagged Rgf1, a putative phosphatidylinositol 4,5-bisphosphate-binding guanine nucleotide exchange factor for Rho protein, in its3-1 mutants was observed, suggesting a defective Rgf1/Rho pathway. To unravel the molecular mechanism(s), putative downstream components of PIP5K signaling were analyzed. Unexpectedly, overexpression of phospholipase C (Plc1), but not that of protein kinase C (PKC; Pck1 and Pck2), suppressed the phenotypes of the its3-1 mutant. These findings indicate that PKCs are not involved in the suppression, and further analysis revealed that PKCs are not downstream of Plc1 in fission yeast. Also, the enzymatic activity of Plc1 is essential for the suppression of the phenotypes and for the viability of the its3-1 mutant. These findings suggest that Its3 PIP5K regulates cell integrity through a Plc1-mediated PKC-independent pathway, in addition to the Rho/PKC pathway.
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Affiliation(s)
- Lu Deng
- Division of Molecular Pharmacology and Pharmacogenomics, Department of Genome Sciences, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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45
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Bürgermeister M, Birner-Grünberger R, Nebauer R, Daum G. Contribution of different pathways to the supply of phosphatidylethanolamine and phosphatidylcholine to mitochondrial membranes of the yeast Saccharomyces cerevisiae. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1686:161-8. [PMID: 15522832 DOI: 10.1016/j.bbalip.2004.09.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2003] [Revised: 08/04/2004] [Accepted: 09/17/2004] [Indexed: 10/26/2022]
Abstract
In the yeast, three biosynthetic pathways lead to the formation of phosphatidylethanolamine (PtdEtn): (i) decarboxylation of phosphatidylserine (PtdSer) by phosphatidylserine decarboxylase 1 (Psd1p) in mitochondria; (ii) decarboxylation of PtdSer by Psd2p in a Golgi/vacuolar compartment; and (iii) the CDP-ethanolamine (CDP-Etn) branch of the Kennedy pathway. The major phospholipid of the yeast, phosphatidylcholine (PtdCho), is formed either by methylation of PtdEtn or via the CDP-choline branch of the Kennedy pathway. To study the contribution of these pathways to the supply of PtdEtn and PtdCho to mitochondrial membranes, labeling experiments in vivo with [(3)H]serine and [(14)C]ethanolamine, or with [(3)H]serine and [(14)C]choline, respectively, and subsequent cell fractionation were performed with psd1Delta and psd2Delta mutants. As shown by comparison of the labeling patterns of the different strains, the major source of cellular and mitochondrial PtdEtn is Psd1p. PtdEtn formed by Psd2p or the CDP-Etn pathway, however, can be imported into mitochondria, although with moderate efficiency. In contrast to mitochondria, microsomal PtdEtn is mainly derived from the CDP-Etn pathway. PtdEtn formed by Psd2p is the preferred substrate for PtdCho synthesis. PtdCho derived from the different pathways appears to be supplied to subcellular membranes from a single PtdCho pool. Thus, the different pathways of PtdEtn biosynthesis play different roles in the assembly of PtdEtn into cellular membranes.
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Affiliation(s)
- Maria Bürgermeister
- Institut für Biochemie, Technische Universität Graz, Petersgasse 12/2, A-8010 Graz, Austria
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Abstract
Phospholipase D catalyses the hydrolysis of the phosphodiester bond of glycerophospholipids to generate phosphatidic acid and a free headgroup. Phospholipase D activities have been detected in simple to complex organisms from viruses and bacteria to yeast, plants, and mammals. Although enzymes with broader selectivity are found in some of the lower organisms, the plant, yeast, and mammalian enzymes are selective for phosphatidylcholine. The two mammalian phospholipase D isoforms are regulated by protein kinases and GTP binding proteins of the ADP-ribosylation and Rho families. Mammalian and yeast phospholipases D are also potently stimulated by phosphatidylinositol 4,5-bisphosphate. This review discusses the identification, characterization, structure, and regulation of phospholipase D. Genetic and pharmacological approaches implicate phospholipase D in a diverse range of cellular processes that include receptor signaling, control of intracellular membrane transport, and reorganization of the actin cytoskeleton. Most ideas about phospholipase D function consider that the phosphatidic acid product is an intracellular lipid messenger. Candidate targets for phospholipase-D-generated phosphatidic acid include phosphatidylinositol 4-phosphate 5-kinases and the raf protein kinase. Phosphatidic acid can also be converted to two other lipid mediators, diacylglycerol and lyso phosphatidic acid. Coordinated activation of these phospholipase-D-dependent pathways likely accounts for the pleitropic roles for these enzymes in many aspects of cell regulation.
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Affiliation(s)
- Mark McDermott
- Department of Cell and Developmental Biology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, 27599-7090, USA
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Carman GM, Kersting MC. Phospholipid synthesis in yeast: regulation by phosphorylation. Biochem Cell Biol 2004; 82:62-70. [PMID: 15052328 DOI: 10.1139/o03-064] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The yeast Saccharomyces cerevisiae is a model eukaryotic organism for the study of the regulation of phospholipid synthesis. The major phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine) are synthesized by complementary (CDP-diacylglycerol and Kennedy) pathways. The regulation of these pathways is complex and is controlled by genetic and biochemical mechanisms. Inositol plays a major role in the regulation of phospholipid synthesis. Inositol-mediated regulation involves the expression of genes and the modulation of enzyme activities. Phosphorylation is a major mechanism by which enzymes and transcription factors are regulated, and indeed, key phospholipid biosynthetic enzymes have been identified as targets of phosphorylation. Protein kinase A phosphorylates CTP synthetase, choline kinase, Mg2+-dependent phosphatidate phosphatase, phosphatidylserine synthase, and the transcription factor Opi1p. CTP synthetase and Opi1p are also phosphorylated by protein kinase C. The phosphorylation of these proteins plays a role in regulating their activities and (or) function in phospholipid synthesis.
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Affiliation(s)
- George M Carman
- Department of Food Science, Rutgers University, New Brunswick, NJ 08901, USA.
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Ogino C, Kuroda S, Tokuyama S, Kondo A, Shimizu N, Tanizawa K, Fukuda H. Phospholipase D from Streptoverticillium cinnamoneum: protein engineering and application for phospholipid production. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1177(03)00077-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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49
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Leem YE, Ross IK, Choi HT. Tagging and localization of a phospholipase D gene in Coprinellus congregatus by restriction enzyme-mediated integration and pulsed-field gel electrophoresis. FEMS Microbiol Lett 2003; 225:285-9. [PMID: 12951254 DOI: 10.1016/s0378-1097(03)00556-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
We have identified a phospholipase D gene (pld) fragment from a transformant generated by restriction enzyme-mediated integration in Coprinellus congregatus, which is a mushroom-forming basidiomycete. A fragment of pld of this fungus has been cloned from a transformant by gene tagging. The transformation vector has been inserted into pld and this has resulted in a decreased enzyme activity of the transformant compared with the wild strain. C. congregatus has seven chromosomes, the range of its genome size is 1.6-4.7 Mb and pld is located at chromosome 4 where the transformation vector has been inserted.
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Affiliation(s)
- Young Eun Leem
- Microbial Physiology Lab, Division of Life Sciences, Kangwon National University, Chunchon 200-701, South Korea
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50
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Hong S, Horiuchi H, Ohta A. Molecular cloning of a phospholipase D gene from Aspergillus nidulans and characterization of its deletion mutants. FEMS Microbiol Lett 2003; 224:231-7. [PMID: 12892887 DOI: 10.1016/s0378-1097(03)00440-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We cloned a gene pldA encoding a protein containing phospholipase D (PLD) motifs from a filamentous fungus Aspergillus nidulans. The deduced protein product of pldA consists of 833 amino acids and contains four conserved regions of a PLD gene family. Deletion mutants of pldA grew and formed conidia in a normal manner. Although PLD and transphosphatidylation activities against phosphatidylcholine of the mutant cell extract did not change, the Ca(2+)-dependent PLD activity against phosphatidylethanolamine was significantly reduced, but not in the wild-type cell extract. This activity was markedly enhanced by high osmotic growth conditions in the wild-type cells, and pldA of A. nidulans likely encodes a Ca(2+)-dependent phosphatidylethanolamine-hydrolyzing PLD.
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Affiliation(s)
- Sahyun Hong
- Department of Biotechnology, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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