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Montaño-Rendón F, Grinstein S, Walpole GFW. Monitoring Phosphoinositide Fluxes and Effectors During Leukocyte Chemotaxis and Phagocytosis. Front Cell Dev Biol 2021; 9:626136. [PMID: 33614656 PMCID: PMC7890364 DOI: 10.3389/fcell.2021.626136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/06/2021] [Indexed: 01/22/2023] Open
Abstract
The dynamic re-organization of cellular membranes in response to extracellular stimuli is fundamental to the cell physiology of myeloid and lymphoid cells of the immune system. In addition to maintaining cellular homeostatic functions, remodeling of the plasmalemma and endomembranes endow leukocytes with the potential to relay extracellular signals across their biological membranes to promote rolling adhesion and diapedesis, migration into the tissue parenchyma, and to ingest foreign particles and effete cells. Phosphoinositides, signaling lipids that control the interface of biological membranes with the external environment, are pivotal to this wealth of functions. Here, we highlight the complex metabolic transitions that occur to phosphoinositides during several stages of the leukocyte lifecycle, namely diapedesis, migration, and phagocytosis. We describe classical and recently developed tools that have aided our understanding of these complex lipids. Finally, major downstream effectors of inositides are highlighted including the cytoskeleton, emphasizing the importance of these rare lipids in immunity and disease.
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Affiliation(s)
- Fernando Montaño-Rendón
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada
| | - Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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Vanderlinden LA, Saba LM, Bennett B, Hoffman PL, Tabakoff B. Influence of sex on genetic regulation of "drinking in the dark" alcohol consumption. Mamm Genome 2015; 26:43-56. [PMID: 25559016 DOI: 10.1007/s00335-014-9553-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
Abstract
The ILSXISS (LXS) recombinant inbred (RI) panel of mice is a valuable resource for genetic mapping studies of complex traits, due to its genetic diversity and large number of strains. Male and female mice from this panel were used to investigate genetic influences on alcohol consumption in the "drinking in the dark" (DID) model. Male mice (38 strains) and female mice (36 strains) were given access to 20% ethanol during the early phase of their circadian dark cycle for four consecutive days. The first principal component of alcohol consumption measures on days 2, 3, and 4 was used as a phenotype (DID phenotype) to calculate QTLs, using a SNP marker set for the LXS RI panel. Five QTLs were identified, three of which included a significant genotype by sex interaction, i.e., a significant genotype effect in males and not females. To investigate candidate genes associated with the DID phenotype, data from brain microarray analysis (Affymetrix Mouse Exon 1.0 ST Arrays) of male LXS RI strains were combined with RNA-Seq data (mouse brain transcriptome reconstruction) from the parental ILS and ISS strains in order to identify expressed mouse brain transcripts. Candidate genes were determined based on common eQTL and DID phenotype QTL regions and correlation of transcript expression levels with the DID phenotype. The resulting candidate genes (in particular, Arntl/Bmal1) focused attention on the influence of circadian regulation on the variation in the DID phenotype in this population of mice.
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Affiliation(s)
- Lauren A Vanderlinden
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 E. Montview Blvd., Campus Box: C238, Aurora, CO, 80045, USA,
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Levin R, Grinstein S, Schlam D. Phosphoinositides in phagocytosis and macropinocytosis. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:805-23. [PMID: 25238964 DOI: 10.1016/j.bbalip.2014.09.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/23/2014] [Accepted: 09/08/2014] [Indexed: 01/08/2023]
Abstract
Professional phagocytes provide immunoprotection and aid in the maintenance of tissue homeostasis. They perform these tasks by recognizing, engulfing and eliminating pathogens and endogenous cell debris. Here, we examine the paramount role played by phosphoinositides in phagocytosis and macropinocytosis, two major endocytic routes that mediate the uptake of particulate and fluid matter, respectively. We analyze accumulating literature describing the molecular mechanisms whereby phosphoinositides translate environmental cues into the complex, sophisticated responses that underlie the phagocytic and macropinocytic responses. In addition, we exemplify virulence strategies involving modulation of host cell phosphoinositide signaling that are employed by bacteria to undermine immunity. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Roni Levin
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada
| | - Sergio Grinstein
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada; Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria St., Toronto M5C1N8, Canada.
| | - Daniel Schlam
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada
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Brazzatti JA, Klingler-Hoffmann M, Haylock-Jacobs S, Harata-Lee Y, Niu M, Higgins MD, Kochetkova M, Hoffmann P, McColl SR. Differential roles for the p101 and p84 regulatory subunits of PI3Kγ in tumor growth and metastasis. Oncogene 2011; 31:2350-61. [PMID: 21996737 DOI: 10.1038/onc.2011.414] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Phosphoinositide 3-kinase γ (PI3Kγ) consists of a catalytic subunit p110γ, which forms mutually exclusive dimers with one of the regulatory subunits called p101 and p84/p87(PIKAP). Recently, PI3Kγ emerged as being a potential oncogene because overexpression of the catalytic subunit p110γ or the regulatory subunit p101 leads to oncogenic cellular transformation and malignancy. However, the contribution of the individual subunits to tumor growth and metastasis and the mechanisms involved are not understood. We therefore individually knocked down the PI3Kγ subunits (p84, p101 and p110γ) in MDA-MB-231 cells, which reduced in vitro migration of the cell lines. Knockdown of p110γ or p101 inhibited apoptosis, Akt phosphorylation and lung colonization in SCID mice. Similarly, the knockdown of p110γ and p101 in murine epithelial carcinoma 4T1.2 cells inhibited primary tumor growth and spontaneous metastasis, as well as lung colonization. In contrast, knockdown of p84 in MDA-MB-231 cells enhanced Akt phosphorylation and lung colonization. These findings are the first to implicate differential functions of the two PI3Kγ regulatory subunits in the process of oncogenesis, and indicate that loss of p101 is sufficient to reduce in vivo tumor growth and metastasis to the same extent as that of p110γ.
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Affiliation(s)
- J A Brazzatti
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
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5
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McCullar JS, Malencik DA, Vogel WK, Crofoot KM, Anderson SR, Filtz TM. Calmodulin potentiates G beta gamma activation of phospholipase C-beta3. Biochem Pharmacol 2007; 73:270-8. [PMID: 17118346 PMCID: PMC1866284 DOI: 10.1016/j.bcp.2006.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 10/05/2006] [Accepted: 10/09/2006] [Indexed: 11/25/2022]
Abstract
Phospholipase C-beta (PLC-beta) isozymes (EC 3.1.4.11) hydrolyze the membrane phospholipid phosphatidylinositol-4,5-bisphosphate to generate intracellular second messenger signaling molecules inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) in response to receptor activation and other cellular stimuli. PLCbeta1 and PLCbeta3 isozymes were previously demonstrated to bind the calcium-sensitive molecule calmodulin [McCullar JS, Larsen SA, Millimaki RA, Filtz TM. Calmodulin is a phospholipase C-{beta} interacting protein. J Biol Chem 2003;278(36):33708-13]. We have now shown through fluorescence anisotropy that calmodulin/PLCbeta3 affinities increase with increasing calcium in a physiologically relevant concentration range. The bimolecular affinity constants for calmodulin interaction with PLCbeta1 or PLCbeta3 were estimated as 260 and 200 nM, respectively, from fluorescence anisotropy data. There was no effect of calmodulin on basal or G alpha q-stimulated catalytic activity for either isozyme. However, the interaction between calmodulin and PLCbeta3 leads to potentiation of activation by the G-protein beta gamma dimer in an in vitro assay. 1321N1 cells treated with calmodulin inhibitors concurrent with and post-stimulation of muscarinic receptors significantly reduced [3H]PIP hydrolysis. Together these data are suggestive of cooperative role for calmodulin in the G-protein beta gamma dimer-stimulated activity of PLCbeta3.
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Affiliation(s)
- Jennifer S McCullar
- Molecular and Cellular Biology Graduate Program, Oregon State University, Corvallis, OR 97331, USA
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Jones DR, Pañeda C, Villar AV, Alonso A, Goñi FM, Bütikofer P, Brodbeck U, Shepherd PR, Varela-Nieto I. Phosphorylation of glycosyl-phosphatidylinositol by phosphatidylinositol 3-kinase changes its properties as a substrate for phospholipases. FEBS Lett 2004; 579:59-65. [PMID: 15620691 DOI: 10.1016/j.febslet.2004.11.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2004] [Revised: 11/08/2004] [Accepted: 11/09/2004] [Indexed: 11/27/2022]
Abstract
Phosphatidylinositol 3-kinases (PI3K) phosphorylate the 3-position of the inositol ring of phosphatidylinositol-4,5-bisphosphate to produce phosphatidylinositol-3,4,5-trisphosphate. It is not clear whether PI3K can phosphorylate the inositol group in other biomolecules. We sought to determine whether PI3K was able to use glycosyl-phosphatidylinositol (GPI) as a substrate. This phospholipid may exist either in free form (GPIfree) or forming a lipid anchor (GPIanchor) for the attachment of extracellular proteins to the plasma membrane. We demonstrate the specific PI3K-mediated phosphorylation of the inositol 3-hydroxyl group within both types of GPI by incubating this phospholipid with immunoprecipitated PI3K. The phosphorylated product behaves in HPLC as a derivative of a PI3K lipid product. To our knowledge, this is the first demonstration that PI3K uses lipid substrates other than phosphoinositides. Further, we show that this has potential functional consequences. When GPIfree is phosphorylated, it becomes a poorer substrate for GPI-specific phospholipase D, but a better substrate for phosphatidylinositol-specific phospholipase C. These phosphorylation events may constitute the basis of a previously undescribed signal transduction mechanism.
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Affiliation(s)
- David R Jones
- Department of Cell Signalling, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas, Arturo Duperier 4, 28029 Madrid, Spain.
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7
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Abstract
Phosphoinositides act as precursors of second messengers and membrane ligands for protein modules. Specific lipid kinases and phosphatases are located and differentially regulated in cell organelles, generating a non-uniform distribution of phosphoinositides. Although it is not clear whether and how the phosphoinositide pools are integrated, it is certain that they locally control fundamental processes, including membrane trafficking. This applies to the Golgi complex, where a direct, central role of the phosphatidylinositol 4,5-bisphosphate precursor phosphatidylinositol 4-phosphate has recently been reported.
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Affiliation(s)
- Maria De Matteis
- Department of Cell Biology and Oncology, Istituto di Ricerche Farmacologiche Mario Negri, Consorzio Mario Negri Sud, 66030, Santa Maria Imbaro, Chieti, Italy.
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Affiliation(s)
- J H Exton
- Howard Hughes Medical Institute, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
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Pettitt TR, McDermott M, Saqib KM, Shimwell N, Wakelam MJ. Phospholipase D1b and D2a generate structurally identical phosphatidic acid species in mammalian cells. Biochem J 2001; 360:707-15. [PMID: 11736663 PMCID: PMC1222276 DOI: 10.1042/0264-6021:3600707] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mammalian cells contain different phospholipase D enzymes (PLDs) whose distinct physiological roles are poorly understood and whose products have not been characterized. The development of porcine aortic endothelial (PAE) cell lines able to overexpress PLD-1b or -2a under the control of an inducible promoter has enabled us to characterize both the substrate specificity and the phosphatidic acid (PtdOH) product of these enzymes under controlled conditions. Liquid chromatography-MS analysis showed that PLD1b- and PLD2a-transfected PAE cells, as well as COS7 and Rat1 cells, generate similar PtdOH and, in the presence of butan-1-ol, phosphatidylbutanol (PtdBut) profiles, enriched in mono- and di-unsaturated species, in particular 16:0/18:1. Although PtdBut mass increased, the species profile did not change in cells stimulated with ATP or PMA. Overexpression of PLD made little difference to basal or stimulated PtdBut formation, indicating that activity is tightly regulated in vivo and that factors other than just PLD protein levels limit hydrolytic function. In vitro assays using PLD-enriched lysates showed that the enzyme could utilize both phosphatidylcholine and, much less efficiently, phosphatidylethanolamine, with slight selectivity towards mono- and di-unsaturated species. Phosphatidylinositol was not a substrate. Thus PLD1b and PLD2a hydrolyse a structurally similar substrate pool to generate an identical PtdOH product enriched in mono- and di-unsaturated species that we propose to function as the intracellular messenger forms of this lipid.
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Affiliation(s)
- T R Pettitt
- CRC Institute for Cancer Studies, University of Birmingham, Birmingham B15 2TA, U.K
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Chikhale EG, Balbo A, Galdzicki Z, Rapoport SI, Shetty HU. Measurement of myo-inositol turnover in phosphatidylinositol: description of a model and mass spectrometric method for cultured cortical neurons. Biochemistry 2001; 40:11114-20. [PMID: 11551209 DOI: 10.1021/bi010817k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rates of myo-inositol (Ins) incorporation and turnover in phosphatidylinositol (PtdIns) were determined in cultured mouse cortical neurons. Cells were incubated with deuterium-labeled myo-inositol (Ins) in culture medium free of unlabeled Ins. The time-dependent changes in the specific activity of cytosolic Ins and membrane PtdIns were measured by mass spectrometry. PtdIns turnover was modeled incorporating values for Ins flux, cytosolic dilution, PtdIns concentration, and rate of incorporation into PtdIns. Recycled Ins diluted the labeled precursor pool, and a time course was obtained for this cytosolic process. The specific activity of the precursor pool at the plateau of the time-course curve was 0.43 +/- 0.04 (mean +/- SD). The incorporation of the tracer into PtdIns was linear between 4 and 10 h incubation of the neurons. After factoring in the extent of dilution of the tracer in the precursor pool, the rate of Ins incorporation into PtdIns was found to be 315 +/- 51 nmol (g of protein)(-1) x h(-1). The half-life of Ins in PtdIns was calculated for each point on the linear incorporation curve and then corrected for the tracer reincorporation. The half-life of Ins in PtdIns was 6.7 +/- 0.2 h, which translates into a basal turnover rate of 10.3%/h in this in vitro system. The mathematical model and the stable isotope method described here should allow assessment of the dynamics of PtdIns signaling altered in certain diseases or by agents.
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Affiliation(s)
- E G Chikhale
- Section on Brain Physiology and Metabolism, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA
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11
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The Regulation of Enzymatic Activity and Metabolism. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50014-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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A rapid phospholipase D assay using zirconium precipitation of anionic substrate phospholipids: application to N-acylethanolamine formation in vitro. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)33466-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Hsu AL, Ching TT, Sen G, Wang DS, Bondada S, Authi KS, Chen CS. Novel function of phosphoinositide 3-kinase in T cell Ca2+ signaling. A phosphatidylinositol 3,4,5-trisphosphate-mediated Ca2+ entry mechanism. J Biol Chem 2000; 275:16242-50. [PMID: 10748064 DOI: 10.1074/jbc.m002077200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study presents evidence that phosphoinositide (PI) 3-kinase is involved in T cell Ca(2+) signaling via a phosphatidylinositol 3,4, 5-trisphosphate PI(3,4,5)P(3)-sensitive Ca(2+) entry pathway. First, exogenous PI(3,4,5)P(3) at concentrations close to its physiological levels induces Ca(2+) influx in T cells, whereas PI(3,4)P(2), PI(4, 5)P(2), and PI(3)P have no effect on [Ca(2+)](i). This Ca(2+) entry mechanism is cell type-specific as B cells and a number of cell lines examined do not respond to PI(3,4,5)P(3) stimulation. Second, inhibition of PI 3-kinase by wortmannin and by overexpression of the dominant negative inhibitor Deltap85 suppresses anti-CD3-induced Ca(2+) response, which could be reversed by subsequent exposure to PI(3,4,5)P(3). Third, PI(3,4,5)P(3) is capable of stimulating Ca(2+) efflux from Ca(2+)-loaded plasma membrane vesicles prepared from Jurkat T cells, suggesting that PI(3,4,5)P(3) interacts with a Ca(2+) entry system directly or via a membrane-bound protein. Fourth, although D-myo-inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4, 5)P(4)) mimics PI(3,4,5)P(3) in many aspects of biochemical functions such as membrane binding and Ca(2+) transport, we raise evidence that Ins(1,3,4,5)P(4) does not play a role in anti-CD3- or PI(3,4,5)P(3)-mediated Ca(2+) entry. This PI(3,4,5)P(3)-stimulated Ca(2+) influx connotes physiological significance, considering the pivotal role of PI 3-kinase in the regulation of T cell function. Given that PI 3-kinase and phospholipase C-gamma form multifunctional complexes downstream of many receptor signaling pathways, we hypothesize that PI(3,4,5)P(3)-induced Ca(2+) entry acts concertedly with Ins(1,4,5)P(3)-induced Ca(2+) release in initiating T cell Ca(2+) signaling. By using a biotinylated analog of PI(3,4,5)P(3) as the affinity probe, we have detected several putative PI(3,4,5)P(3)-binding proteins in T cell plasma membranes.
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Affiliation(s)
- A L Hsu
- Division of Pharmaceutical Sciences, College of Pharmacy and Department of Microbiology and Immunology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky 40536, USA
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Lainé J, Bourgoin S, Bourassa J, Morisset J. Subcellular distribution and characterization of rat pancreatic phospholipase D isoforms. Pancreas 2000; 20:323-36. [PMID: 10824686 DOI: 10.1097/00006676-200005000-00001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study was undertaken to characterize the biochemical properties of rat pancreatic phospholipase D (PLD). Based on Western blot analysis of pancreas subcellular fractions, PLD1 was detected as a protein of 120 kDa associated with the microsomal fraction, whereas PLD2 appeared as a 105-kDa protein enriched in the microvesicular fraction. In these fractions, a low level of PLD activity was measured with an exogenous substrate containing phosphatidylinositol-4,5-bisphosphate (PIP2), unresponsive to guanosine triphosphate (GTP)gammaS and adenosine diphosphate (ADP)-ribosylation factor (ARF). Addition of unsaturated but not saturated fatty acids stimulated an oleate-dependent PLD activity that colocalized with the PLD1 enzyme in the crude plasma membrane and microsomal fractions. The transphosphatidylation reaction was maximal with either 200-400 mM (1.2-2.3%) ethanol or 25 mM (0.23%) 1-butanol, with an optimal pH between 6.5 and 7.2. Lipids extracted from the pancreatic membranes were potent inhibitors of the HL60 cell PLD activity when compared with those isolated from HL60 cells. Oleate-dependent PLD activity was less susceptible to these inhibitions. A phospholipase A1 (PLA1) activity hydrolyzing phosphatidylethanol also was found in the pancreatic membrane fractions and was nearly absent in the HL60 cells. This activity was completely inhibited by 400 nM tetrahydrolipstatin (THL), a lipase inhibitor. Pancreatic PLD1 and PLD2 activities could be measured after a chromatographic separation from microsomal membranes and high-speed supernatants, respectively. Activities of both enzymes were inhibited by oleate and required the presence of PIP2 in the substrate vesicles. ARF1 strongly activated PLD1 in a dose-dependent manner, and PLD2 was slightly responsive. Indirect immunofluorescence revealed that PLD2 is distributed throughout the pancreas, with a more intense staining in the islets. This study presents for the first time biochemical characteristics of the pancreatic PLD activities and shows the presence of oleate-dependent PLD1 and PLD2 activities, as well as PLD1 and PLD2 proteins in this gland.
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Affiliation(s)
- J Lainé
- Service de Gastroentérologie, Département de Médecine, Faculté de Médecine, Université de Sherbrooke, Québec, Canada
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Wang X. Multiple forms of phospholipase D in plants: the gene family, catalytic and regulatory properties, and cellular functions. Prog Lipid Res 2000; 39:109-49. [PMID: 10775762 DOI: 10.1016/s0163-7827(00)00002-3] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiple Phospholipase D (PLD) genes have been identified in plants and encode isoforms with distinct regulatory and catalytic properties. Elucidation of the genetic and biochemical heterogeneity has provided important clues as to the regulation and function of this family of enzymes. Polyphosphoinositides, Ca(2+), and G-proteins are possible cellular regulators for PLD activation. PLD-mediated hydrolysis of membrane lipids increases in response to various stresses. Recent studies suggest that PLD plays a role in the signaling and production of hormones involved in plant stress responses.
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Affiliation(s)
- X Wang
- Department of Biochemistry, Kansas State University, Manhattan 66506, USA.
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