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Vilas Boas LCP, Buccini DF, Berlanda RLA, Santos BDPO, Maximiano MR, Lião LM, Gonçalves S, Santos NC, Franco OL. Antiviral Activities of Mastoparan-L-Derived Peptides against Human Alphaherpesvirus 1. Viruses 2024; 16:948. [PMID: 38932240 PMCID: PMC11209138 DOI: 10.3390/v16060948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 06/01/2024] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Human alphaherpesvirus 1 (HSV-1) is a significantly widespread viral pathogen causing recurrent infections that are currently incurable despite available treatment protocols. Studies have highlighted the potential of antimicrobial peptides sourced from Vespula lewisii venom, particularly those belonging to the mastoparan family, as effective against HSV-1. This study aimed to demonstrate the antiviral properties of mastoparans, including mastoparan-L [I5, R8], mastoparan-MO, and [I5, R8] mastoparan, against HSV-1. Initially, Vero cell viability was assessed in the presence of these peptides, followed by the determination of antiviral activity, mechanism of action, and dose-response curves through plaque assays. Structural analyses via circular dichroism and nuclear magnetic resonance were conducted, along with evaluating membrane fluidity changes induced by [I5, R8] mastoparan using fluorescence-labeled lipid vesicles. Cytotoxic assays revealed high cell viability (>80%) at concentrations of 200 µg/mL for mastoparan-L and mastoparan-MO and 50 µg/mL for [I5, R8] mastoparan. Mastoparan-MO and [I5, R8] mastoparan exhibited over 80% HSV-1 inhibition, with up to 99% viral replication inhibition, particularly in the early infection stages. Structural analysis indicated an α-helical structure for [I5, R8] mastoparan, suggesting effective viral particle disruption before cell attachment. Mastoparans present promising prospects for HSV-1 infection control, although further investigation into their mechanisms is warranted.
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Affiliation(s)
- Liana Costa Pereira Vilas Boas
- Pós-Graduação em Patologia Molecular, Campus Darcy Ribeiro, Universidade de Brasília, Brasília 70910-900, DF, Brazil
- Centro de Análises Bioquímicas e Proteômicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília 70790-760, DF, Brazil
| | - Danieli Fernanda Buccini
- Centro de Análises Bioquímicas e Proteômicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília 70790-760, DF, Brazil
- Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande 79117-900, MS, Brazil
| | - Rhayfa Lorrayne Araújo Berlanda
- Pós-Graduação em Patologia Molecular, Campus Darcy Ribeiro, Universidade de Brasília, Brasília 70910-900, DF, Brazil
- Centro de Análises Bioquímicas e Proteômicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília 70790-760, DF, Brazil
| | - Bruno de Paula Oliveira Santos
- Laboratório de Ressonância Magnética Nuclear, Instituto de Química, Universidade Federal de Goiás, Goiânia 74690-900, GO, Brazil
| | - Mariana Rocha Maximiano
- Centro de Análises Bioquímicas e Proteômicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília 70790-760, DF, Brazil
- Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande 79117-900, MS, Brazil
| | - Luciano Morais Lião
- Laboratório de Ressonância Magnética Nuclear, Instituto de Química, Universidade Federal de Goiás, Goiânia 74690-900, GO, Brazil
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal (N.C.S.)
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal (N.C.S.)
| | - Octávio Luiz Franco
- Pós-Graduação em Patologia Molecular, Campus Darcy Ribeiro, Universidade de Brasília, Brasília 70910-900, DF, Brazil
- Centro de Análises Bioquímicas e Proteômicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília 70790-760, DF, Brazil
- Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande 79117-900, MS, Brazil
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de Santana CJC, Pires Júnior OR, Fontes W, Palma MS, Castro MS. Mastoparans: A Group of Multifunctional α-Helical Peptides With Promising Therapeutic Properties. Front Mol Biosci 2022; 9:824989. [PMID: 35813822 PMCID: PMC9263278 DOI: 10.3389/fmolb.2022.824989] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Biologically active peptides have been attracting increasing attention, whether to improve the understanding of their mechanisms of action or in the search for new therapeutic drugs. Wasp venoms have been explored as a remarkable source for these molecules. In this review, the main findings on the group of wasp linear cationic α-helical peptides called mastoparans were discussed. These compounds have a wide variety of biological effects, including mast cell degranulation, activation of protein G, phospholipase A2, C, and D activation, serotonin and insulin release, and antimicrobial, hemolytic, and anticancer activities, which could lead to the development of new therapeutic agents.
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Affiliation(s)
- Carlos José Correia de Santana
- Laboratory of Toxinology, Department of Physiological Sciences, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Osmindo Rodrigues Pires Júnior
- Laboratory of Toxinology, Department of Physiological Sciences, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Wagner Fontes
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Mário Sérgio Palma
- Department of Basic and Applied Biology, Institute of Biosciences of Rio Claro, São Paulo State University, UNESP, Rio Claro, Brazil
| | - Mariana S. Castro
- Laboratory of Toxinology, Department of Physiological Sciences, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
- *Correspondence: Mariana S. Castro,
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Phosphatidic Acid (PA) can Displace PPARα/LXRα Binding to The EGFR Promoter Causing its Transrepression in Luminal Cancer Cells. Sci Rep 2015; 5:15379. [PMID: 26493292 PMCID: PMC4615983 DOI: 10.1038/srep15379] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 08/24/2015] [Indexed: 12/14/2022] Open
Abstract
The expression of the epidermal growth factor receptor (EGFR) is highly regulated in normal cells, whereas some cancer cells have high constitutive levels. Understanding naturally-occurring ways of downregulating EGFR in cancer cells was investigated. Phosphatidic acid (PA) or Nuclear Receptors (NR) PPARα/RXRα/LXRα, enhance EGFR expression, mediated by the promoter region -856(A) to -226(T). Unexpectedly, the combination of NRs and PA caused repression. PA induces a conformational change in the nuclear receptor PPARα (increase of alpha-helices at the expense of decreasing beta-sheets), as evidenced by circular dichroism. This represses the naturally-enhancing capability of PPARα on EGFR transcription. PPARα-overexpressing cells in the presence of PA > 300 nM or the enzyme that produces it, phospholipase D (PLD), downregulate EGFR expression. The reasons are two-fold. First, PA displaces PPARα binding to the EGFR promoter at those concentrations. Second, NR heterodimer-dependent promoter activity is weakened in the presence of PA in vivo. Since other genes considered (β-catenin, cyclin D3, PLD2 and ACOX-1) are also downregulated with a PA + PPARα combination, the transrepression appears to be a global phenomenon. Lastly, the reported effect is greater in MCF-7 than in MDA-MB-231 breast cancer cells, which could provide a novel basis for regulating excessive expression of EGFR in luminal cancer cells.
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Phorbol ester stimulates ethanolamine release from the metastatic basal prostate cancer cell line PC3 but not from prostate epithelial cell lines LNCaP and P4E6. Br J Cancer 2014; 111:1646-56. [PMID: 25137020 PMCID: PMC4200097 DOI: 10.1038/bjc.2014.457] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/09/2014] [Accepted: 07/21/2014] [Indexed: 12/11/2022] Open
Abstract
Background: Malignancy alters cellular complex lipid metabolism and membrane lipid composition and turnover. Here, we investigated whether tumorigenesis in cancer-derived prostate epithelial cell lines influences protein kinase C-linked turnover of ethanolamine phosphoglycerides (EtnPGs) and alters the pattern of ethanolamine (Etn) metabolites released to the medium. Methods: Prostate epithelial cell lines P4E6, LNCaP and PC3 were models of prostate cancer (PCa). PNT2C2 and PNT1A were models of benign prostate epithelia. Cellular EtnPGs were labelled with [1-3H]-Etn hydrochloride. PKC was activated with phorbol ester (TPA) and inhibited with Ro31-8220 and GF109203X. D609 was used to inhibit PLD (phospholipase D). [3H]-labelled Etn metabolites were resolved by ion-exchange chromatography. Sodium oleate and mastoparan were tested as activators of PLD2. Phospholipase D activity was measured by a transphosphatidylation reaction. Cells were treated with ionomycin to raise intracellular Ca2+ levels. Results: Unstimulated cell lines release mainly Etn and glycerylphosphorylEtn (GPEtn) to the medium. Phorbol ester treatment over 3h increased Etn metabolite release from the metastatic PC3 cell line and the benign cell lines PNT2C2 and PNT1A but not from the tumour-derived cell lines P4E6 and LNCaP; this effect was blocked by Ro31-8220 and GF109203X as well as by D609, which inhibited PLD in a transphosphatidylation reaction. Only metastatic PC3 cells specifically upregulated Etn release in response to TPA treatment. Oleate and mastoparan increased GPEtn release from all cell lines at the expense of Etn. Ionomycin stimulated GPEtn release from benign PNT2C2 cells but not from cancer-derived cell lines P4E6 or PC3. Ethanolamine did not stimulate the proliferation of LNCaP or PC3 cell lines but decreased the uptake of choline (Cho). Conclusions: Only the metastatic basal PC3 cell line specifically increased the release of Etn on TPA treatment most probably by PKC activation of PLD1 and increased turnover of EtnPGs. The phosphatidic acid formed will maintain a cancer phenotype through the regulation of mTOR. Ethanolamine released from cells may reduce Cho uptake, regulating the membrane PtdEtn:PtdCho ratio and influencing the action of PtdEtn-binding proteins such as RKIP and the anti-apoptotic hPEBP4. The work highlights a difference between LNCaP cells used as a model of androgen-dependent early stage PCa and androgen-independent PC3 cells used to model later refractory stage disease.
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The influence of polyunsaturated fatty acids on the phospholipase D isoforms trafficking and activity in mast cells. Int J Mol Sci 2013; 14:9005-17. [PMID: 23698760 PMCID: PMC3676769 DOI: 10.3390/ijms14059005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/15/2013] [Accepted: 04/18/2013] [Indexed: 11/16/2022] Open
Abstract
The impact of polyunsaturated fatty acid (PUFA) supplementation on phospholipase D (PLD) trafficking and activity in mast cells was investigated. The enrichment of mast cells with different PUFA including α-linolenic acid (LNA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid (LA) or arachidonic acid (AA) revealed a PUFA-mediated modulation of the mastoparan-stimulated PLD trafficking and activity. All PUFA examined, except AA, prevented the migration of the PLD1 to the plasma membrane. For PLD2 no PUFA effects on trafficking could be observed. Moreover, PUFA supplementation resulted in an increase of mastoparan-stimulated total PLD activity, which correlated with the number of double bonds of the supplemented fatty acids. To investigate, which PLD isoform was affected by PUFA, stimulated mast cells were supplemented with DHA or AA in the presence of specific PLD-isoform inhibitors. It was found that both DHA and AA diminished the inhibition of PLD activity in the presence of a PLD1 inhibitor. By contrast, only AA diminished the inhibition of PLD activity in the presence of a PLD2 inhibitor. Thus, PUFA modulate the trafficking and activity of PLD isoforms in mast cells differently. This may, in part, account for the immunomodulatory effect of unsaturated fatty acids and contributes to our understanding of the modulation of mast cell activity by PUFA.
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Jones S, Howl J. Enantiomer-Specific Bioactivities of Peptidomimetic Analogues of Mastoparan and Mitoparan: Characterization of Inverso Mastoparan as a Highly Efficient Cell Penetrating Peptide. Bioconjug Chem 2012; 23:47-56. [DOI: 10.1021/bc2002924] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sarah Jones
- Research Institute in Healthcare Science,
School of
Applied Sciences, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1LY, United Kingdom
| | - John Howl
- Research Institute in Healthcare Science,
School of
Applied Sciences, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1LY, United Kingdom
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Abstract
Phosphatidylinositol 4-phosphate (PtdIns4P) is a quantitatively minor membrane phospholipid which is the precursor of PtdIns(4,5)P (2) in the classical agonist-regulated phospholipase C signalling pathway. However, PtdIns4P also governs the recruitment and function of numerous trafficking molecules, principally in the Golgi complex. The majority of phosphoinositides (PIs) phosphorylated at the D4 position of the inositol headgroup are derived from PtdIns4P and play roles in a diverse array of fundamental cellular processes including secretion, cell migration, apoptosis and mitogenesis; therefore, PtdIns4P biosynthesis can be regarded as key point of regulation in many PI-dependent processes.Two structurally distinct sequence families, the type II and type III PtdIns 4-kinases, are responsible for PtdIns4P synthesis in eukaryotic organisms. These important proteins are differentially expressed, localised and regulated by distinct mechanisms, indicating that the enzymes perform non-redundant roles in trafficking and signalling. In recent years, major advances have been made in our understanding of PtdIns4K biology and here we summarise current knowledge of PtdIns4K structure, function and regulation.
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Affiliation(s)
- Shane Minogue
- Centre for Molecular Cell Biology, Department of Inflammation, Division of Medicine, University College London, Rowland Hill Street, Hampstead, NW3 2PF, London, United Kingdom,
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Abstract
Mast cells are multifunctional cells that initiate not only IgE-dependent allergic diseases but also play a fundamental role in innate and adaptive immune responses to microbial infection. They are also thought to play a role in angiogenesis, tissue remodeling, wound healing, and tumor repression or growth. The broad scope of these physiologic and pathologic roles illustrates the flexible nature of mast cells, which is enabled in part by their phenotypic adaptability to different tissue microenvironments and their ability to generate and release a diverse array of bioactive mediators in response to multiple types of cell-surface and cytosolic receptors. There is increasing evidence from studies in cell cultures that release of these mediators can be selectively modulated depending on the types or groups of receptors activated. The intent of this review is to foster interest in the interplay among mast cell receptors to help understand the underlying mechanisms for each of the immunological and non-immunological functions attributed to mast cells. The second intent of this review is to assess the pathophysiologic roles of mast cells and their products in health and disease. Although mast cells have a sufficient repertoire of bioactive mediators to mount effective innate and adaptive defense mechanisms against invading microorganisms, these same mediators can adversely affect surrounding tissues in the host, resulting in autoimmune disease as well as allergic disorders.
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Affiliation(s)
- Alasdair M Gilfillan
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1881, USA.
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Nishikawa H, Kitani S. Inhibitory effect of ganglioside on mastoparan-induced cytotoxicity and degranulation in lipid raft of connective tissue type mast cell. J Biochem Mol Toxicol 2010; 25:158-68. [PMID: 21671308 DOI: 10.1002/jbt.20372] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2010] [Revised: 07/22/2010] [Accepted: 08/21/2010] [Indexed: 12/16/2022]
Abstract
Antihistamine, the most important drug for Hymenoptera stinging, cannot attenuate cytotoxicity and mast cell direct activation by mastoparan that is the most abundant polypeptides in the venoms of social wasps. The aim of this study was to investigate whether gangliosides inhibit the effect of mastoparan on mast cells activation. The degranulation and cytotoxicity in canine cutaneous mastocytoma cells (CM-MC) were done by measurement of β-hexosaminidase release and MTT assay. Lipid raft was isolated with discontinuous sucrose gradient centrifuge for the analysis of distribution of Gα(q) and Gα(i) protein by western blotting. We found that mastoparan induced the degranulation in (CM-MC) via direct activation of Gα(i) and Gα(q) with a decrease in their amount in lipid raft. Ganglioside G(D1a) (disialoganglioside) and G(M1) (monosialoganglioside) strongly reduced the degranulation and cytotoxicity through stabilizing the structure of lipid raft domain. In addition, mastoparan generated intracellular reactive oxygen species (ROS) independently from cytotoxicity, through arachidonic cascade but not G-protein activations. Crude wasp venom showed cytotoxicity and induction of the release from CM-MC, which were potently reduced by gangliosides. We show here that mastoparan activates both Gα(i) and Gα(q) protein and that the exogenous ganglioside G(D1a) and G(M1) inhibit the degranulation and cytotoxicity through stabilizing lipid raft. Gangliosides have potentials to be therapeutic tool or clinical prophylaxis for wasp stinging.
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Affiliation(s)
- Hirofumi Nishikawa
- Department of Food Science and Technology, Graduate School of Marine Science and Technology, Tokyo
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Nakahata N, Sugama J. [Pharmacological activity of mastoparan: its contribution to signal transduction]. Nihon Yakurigaku Zasshi 2010; 136:145-149. [PMID: 20838016 DOI: 10.1254/fpj.136.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Docking study of the precursor peptide of mastoparan onto its putative processing enzyme, dipeptidyl peptidase IV: a revisit to molecular ticketing. J Comput Aided Mol Des 2010; 24:213-24. [PMID: 20306218 DOI: 10.1007/s10822-010-9327-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
Abstract
Stepwise-cleavage process of promastoparans to reach maturity was investigated theoretically by combining ab initio folding and unbounded docking. The comparison between the structures of the promastoparans both before and after docking were examined along with the hydrogen bonding interaction pattern between the dipetidyl peptidase IV (DPPIV) and promastoparans to reveal how the endpoint of this stepwise cleavage is recognized among these promastoparans with highly resemble amino acid sequences. The current approach of folding and docking study provides structural insight on the stepwise cleavage process.
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12
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Activation of Gi induces mechanical hyperalgesia poststress or inflammation. Neuroscience 2009; 160:501-7. [PMID: 19275929 DOI: 10.1016/j.neuroscience.2009.03.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 03/02/2009] [Accepted: 03/03/2009] [Indexed: 11/24/2022]
Abstract
In studies of the role of primary afferent nociceptor plasticity in the transition from acute to chronic pain we recently reported that exposure to unpredictable sound stress or a prior inflammatory response induces long-term changes in the second messenger signaling pathway, in nociceptors, mediating inflammatory hyperalgesia; this change involves a switch from a G(s)-cAMP-PKA to a G(i)-PKCepsilon signaling pathway. To more directly study the role of G(i) in mechanical hyperalgesia we evaluated the nociceptive effect of the G(i) activator, mastoparan. Intradermal injection of mastoparan in the rat hind paw induces dose-dependent (0.1 ng-1 microg) mechanical hyperalgesia. The highly selective inhibitors of G(i), pertussis toxin, and of protein kinase C epsilon (PKCepsilon), PKCepsilonV(1-2), both markedly attenuate mastoparan-induced hyperalgesia in stressed rats but had no effect on mastoparan-induced hyperalgesia in unstressed rats. Similar effects were observed, at the site of nociceptive testing, after recovery from carrageenan-induced inflammation. These studies provide further confirmation for a switch to a G(i)-activated and PKCepsilon-dependent signaling pathway in primary mechanical hyperalgesia, induced by stress or inflammation.
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Gemeinhardt A, Alfalah M, Gück T, Naim HY, Fuhrmann H. The influence of linoleic and linolenic acid on the activity and intracellular localisation of phospholipase D in COS-1 cells. Biol Chem 2009; 390:253-8. [DOI: 10.1515/bc.2009.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractPhospholipase D (PLD) is a receptor-regulated signalling enzyme involved in biological functions, such as exocytosis, phagocytosis, actin dynamics, membrane trafficking, and is considered to be essential for stimulated degranulation of cells. The purpose of our investigation was to examine how the fatty acid pattern of cellular membranes influences the activities and cellular distribution of the PLD1 and PLD2 isoforms. Expression of GFP-tagged PLD1 and PLD2 in COS-1 cells that were stimulated with mastoparan after cultivation in 20 μmol linoleic (C18:2n6) or linolenic (C18:3n3) acid for 4 d demonstrated that PLD1 dramatically alters its cellular distribution and is redistributed from intracellular vesicles to the cell surface. PLD2, on the other hand, maintains its localisation at the plasma membrane. The activity of PLD, which corresponds to PLD1 and PLD2, significantly increased two- to three-fold in the presence of the fatty acids. We conclude that linoleic acid and linolenic acid supplementation affect the intracellular trafficking of the PLD1 isoform and the activity of PLD most likely due to alterations in the membrane lipid environment conferred by the fatty acids.
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Rocha T, Leonardo MB, De Souza BM, Palma MS, Da Cruz-Höfling MA. Mastoparan effects in skeletal muscle damage: An ultrastructural view until now concealed. Microsc Res Tech 2008; 71:220-9. [DOI: 10.1002/jemt.20542] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Sugama J, Yu JZ, Rasenick MM, Nakahata N. Mastoparan inhibits beta-adrenoceptor-G(s) signaling by changing the localization of Galpha(s) in lipid rafts. Cell Signal 2007; 19:2247-54. [PMID: 17692506 DOI: 10.1016/j.cellsig.2007.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 06/21/2007] [Indexed: 11/19/2022]
Abstract
Mastoparan, a wasp venom toxin, has various pharmacological activities, the mechanisms of which are still unknown. To clarify the action of mastoparan on G protein-coupled receptor-mediated signaling, we previously examined the effect of mastoparan on G(q)-mediated signaling and demonstrated that mastoparan binds to gangliosides causing a decrease in Galpha(q/11) content in lipid rafts, and resulting in the inhibition of G(q)-mediated phosphoinositide hydrolysis (Sugama et al., Mol. Pharmacol., 68, 1466, 2005). In the present study, we examined the effect of mastoparan on beta-adrenoceptor-G(s) signaling in 1321N1 human astrocytoma cells. Mastoparan inhibited isoproterenol-induced elevation of cyclic AMP in a concentration-dependent manner. Although mastoparan is known to be an activator of G(i), pertussis toxin only slightly attenuated mastoparan-induced inhibition of cyclic AMP elevation, suggesting that a major part of the inhibition of cyclic AMP elevation induced by mastoparan is not mediated by Galpha(i). By contrast, mastoparan-induced inhibition of cyclic AMP elevation was clearly attenuated by preincubation of the cells with ganglioside mixtures. Moreover, mastoparan changed the localization of Galpha(s) in lipid rafts without disrupting the structure of lipid rafts. Fluorescent staining analysis showed that mastoparan released GFP-Galpha(s) from plasma membranes into the cytosol. These results suggest that the mastoparan-induced suppression of cyclic AMP elevation is mainly caused by changing the localization of Galpha(s) in lipid rafts into a compartment in the cellular interior where it is not available to activate adenylyl cyclase.
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Affiliation(s)
- Jun Sugama
- Department of Cellular Signaling, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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Lee VSY, Tu WC, Jinn TR, Peng CC, Lin LJ, Tzen JTC. Molecular cloning of the precursor polypeptide of mastoparan B and its putative processing enzyme, dipeptidyl peptidase IV, from the black-bellied hornet, Vespa basalis. INSECT MOLECULAR BIOLOGY 2007; 16:231-7. [PMID: 17298553 DOI: 10.1111/j.1365-2583.2006.00718.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Mastoparan B, a cationic toxin, is the major peptide component in the venom of Vespa basalis. Molecular cloning of its cDNA fragment revealed that this toxin was initially synthesized as a precursor polypeptide, containing an N-terminal signal sequence, a prosequence, the mature toxin, and an appendix glycine at C-terminus. Sequence alignment between precursors of mastoparan B and melittin from honeybee venom showed a significant conservation in prosequence. Alternate positions existing in both prosequences were either proline or alanine known as the potential cleaving sites for dipeptidyl peptidase IV. Subsequently, a putative dipeptidyl peptidase IV cDNA fragment was cloned from Vespa basalis venom gland. The prosequence may possibly be removed via sequential liberation of dipeptides during the processing of mastoparan B.
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Affiliation(s)
- V S Y Lee
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
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Palomäki VAB, Laitinen JT. The basic secretagogue compound 48/80 activates G proteins indirectly via stimulation of phospholipase D-lysophosphatidic acid receptor axis and 5-HT1A receptors in rat brain sections. Br J Pharmacol 2006; 147:596-606. [PMID: 16415902 PMCID: PMC1751339 DOI: 10.1038/sj.bjp.0706671] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The basic secretagogues, such as compound 48/80 (c48/80) and mastoparans, are widely used histamine-releasing agents and their mechanism of action is commonly attributed to a direct, receptor-bypassing property to activate the G(i/o) class of G proteins. We tested here whether c48/80 could directly stimulate [(35)S]guanosine-5'-[gamma-thio]triphosphate ([(35)S]GTPgammaS) binding to rat brain sections in an attempt to visualize the entire signaling pool of G(i/o) in its native neuroanatomical context. Instead of direct G(i/o) activation, c48/80 (100 microg ml(-1)) from various suppliers stimulated brain phospholipase D (PLD) activity, leading to the generation of endogenous phospholipids capable of activating brain white matter-enriched, G(i/o)-coupled lysophosphatidic acid (LPA) receptors. This response was sensitive to 1-butanol and was potently reversed by the LPA(1)/LPA(3) receptor-selective antagonist Ki16425 (IC(50) 59+/-13 nM, mean+/-s.e.m.), and showed age-dependent decline, closely reflecting known developmental regulation of the PLD-LPA(1) receptor axis in the CNS. In addition, c48/80 was found to modestly activate hippocampal 5-HT(1A) receptors in a pH-dependent and antagonist-sensitive manner. Consistent with the lack of direct G(i/o)-activating properties in brain sections, c48/80 showed no activity in classical membrane [(35)S]GTPgammaS binding assays. Instead, c48/80 from one particular manufacturer elicited non-specific effect in these assays, therefore challenging the previous interpretations regarding the compound's ability to activate G proteins directly. We conclude that c48/80 is not a receptor-bypassing general G protein activator but rather activates PLD, leading to generation of endogenous LPA receptor-activating phospholipids. This property may also contribute to the compound's ability to release histamine from mast cells.
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Affiliation(s)
- Ville A B Palomäki
- Department of Physiology, University of Kuopio, POB 1627, FIN-70211 Kuopio, Finland.
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Kim JY, Kwon EY, Lee YS, Kim WB, Ro JY. Eupatilin blocks mediator release via tyrosine kinase inhibition in activated guinea pig lung mast cells. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2005; 68:2063-80. [PMID: 16326424 DOI: 10.1080/15287390500177024] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Eupatilin, an extract from Artemisia asiatica Nakai, is known to exert anti-gastric ulcer, anticancer, and anti-inflammatory effects. The aim of this study was to elucidate whether eupatilin has antiallergic reactions in activated guinea pig lung mast cells compared to apigenin and genistein. Mast cells were purified from guinea pig lung tissues by using enzyme digestion and rough and discontinuous density Percoll gradient. The purified mast cells were sensitized with immunoglobulin (Ig) G(1) (anti-OVA antibody) and challenged with ovalbumin (OVA). Histamine was assayed using an automated fluorometric analyzer, leukotrienes by radioimmunoassay, and tyrosine phosphorylation by immunoblotting. Intracellular Ca(2+) was analyzed by confocal laser scanning microscopy, protein kinase C (PKC) activity using protein phosphorylated with [gamma-(32)P]ATP, and phopholipase D activity (PLD) and phosphatidic acid by using labeled phosphatidyl alcohol. Eupatilin, apigenin, or genistein reduced histamine release and leukotriene synthesis in a does-dependent manner. Eupatilin inhibited mediators to a greater extent than apigenin or genistein. Eupatilin, apigenin, and genistein initially blocked phosphorylation of Syk tyrosine and Ca(2+) influx, PLD activity, phosphatidic acid, and Ca(2+)-dependent PKC alpha/betaII activities during mast cell activation in a dose-dependent manner. Our data suggest that eupatilin initially inhibits Syk kinase, and then blocks downstream multisignal pathways and Ca(2+) influx during mast cell activation triggered by a specific antigen-antibody reaction. Thus, eupatilin may have use clinically as a treatment for inflammatory disorders associated with allergic diseases including asthma.
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Affiliation(s)
- Ji Young Kim
- Research Laboratories, Dong-A Pharmaceutics Co. Ltd., Yonginsi, Kyunggido, Korea
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19
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Waugh MG, Minogue S, Chotai D, Berditchevski F, Hsuan JJ. Lipid and peptide control of phosphatidylinositol 4-kinase IIalpha activity on Golgi-endosomal Rafts. J Biol Chem 2005; 281:3757-63. [PMID: 16249177 DOI: 10.1074/jbc.m506527200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The most abundant and widely expressed mammalian phosphoinositide kinase activity is contributed by phosphatidylinositol 4-kinase IIalpha (PI4KIIalpha). In this study we demonstrate that PI4KIIalpha is a novel GTP-independent target of the wasp venom tetradecapeptide mastoparan and that different mechanisms of activation occur in different subcellular membranes. Following cell membrane fractionation mastoparan specifically stimulated a high activity Golgi/endosomal pool of PI4KIIalpha independently of exogenous guanine nucleotides. Conversely, GTPgammaS stimulated a low activity pool of PI4KIIalpha in a separable dense membrane fraction and this response was further enhanced by mastoparan. Overexpression of PI4KIIalpha increased the basal phosphatidylinositol 4-kinase activity of each membrane pool, as well as the mastoparan-dependent activities, thereby demonstrating that mastoparan specifically activates this isozyme. Both mastoparan and M7, at concentrations known to invoke secretion, stimulated PI4KIIalpha with similar efficacies, resulting in an increase in the apparent V(max) and decrease in K(m) for exogenously added PI. Mastoparan also stimulated PI4KIIalpha immunoprecipitated from the raft fraction, indicating that PI4KIIalpha is a direct target of mastoparan. Finally we reveal a striking dependence of both basal and mastoparan-stimulated PI4KIIalpha activity on endogenous cholesterol concentration and therefore conclude that changes in membrane environment can regulate PI4KIIalpha activity.
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Affiliation(s)
- Mark G Waugh
- Centre for Molecular Cell Biology, Department of Medicine, Royal Free and University College Medical School, University College London, UK
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20
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Wang Y, Oram JF. Unsaturated fatty acids phosphorylate and destabilize ABCA1 through a phospholipase D2 pathway. J Biol Chem 2005; 280:35896-903. [PMID: 16118212 DOI: 10.1074/jbc.m506210200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Abnormal high density lipoprotein (HDL) metabolism among patients with diabetes and insulin resistance may contribute to their increased risk of atherosclerosis. ATP-binding cassette transporter ABCA1 mediates the transport of cholesterol and phospholipids from cells to HDL apolipoproteins and thus modulates HDL levels and atherogenesis. Unsaturated fatty acids, which are elevated in diabetes, impair the ABCA1 pathway in cultured cells by destabilizing ABCA1 protein. Here we examined the cellular pathway that mediates the ABCA1 destabilizing effects of fatty acids. The long-chain acyl-CoA synthetase inhibitor triacsin C completely reversed fatty acid-induced ABCA1 destabilization, indicating that fatty acids need to be activated to their CoA derivatives to enhance ABCA1 degradation. Unsaturated but not saturated fatty acids stimulated phospholipase D (PLD) activity, the PLD inhibitor 1-butanol prevented the unsaturated fatty acid-induced reduction in ABCA1 levels, and the PLD2 activator mastoparan markedly reduced ABCA1 protein levels, implicating a role for PLD2 in the ABCA1 destabilizing effects of fatty acids. Unsaturated fatty acids and mastoparan increased phosphorylation of ABCA1 serines. PLD2 small interfering RNA abolished the ability of unsaturated fatty acids to inhibit lipid transport activity, to reduce protein levels, and to increase serine phosphorylation of ABCA1. The diacylglycerol analog oleoylacetylglycerol also reduced ABCA1 protein levels and increased its serine phosphorylation, suggesting that PLD2-generated diacylglycerols promote the destabilizing phosphorylation of ABCA1. These data provide evidence that intracellular unsaturated acyl-CoA derivatives destabilize ABCA1 by activating a PLD2 signaling pathway.
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Affiliation(s)
- Yutong Wang
- Department of Medicine, University of Washington, Seattle, Washington 98195, USA
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21
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Abstract
Phospholipase D (PLD) and ADP-ribosylation factor 6 (ARF6) have been implicated in vesicular trafficking and rearrangement of the actin cytoskeleton. We have explored the co-localization of rat PLD1b and rat PLD2 with wild type and mutant forms of ARF6 in HeLa cells and studied their activation by ARF6 and the role of the actin cytoskeleton. GFP-tagged PLD1 had a similar pattern to multivesicular and late endosomes and the trans-Golgi apparatus, but not to other organelles. When wild type or dominant negative ARF6 and PLD1 or PLD2 were co-expressed, they had a similar localization in cytosolic particles and at the cell periphery. In contrast, dominant active ARF6 caused cell shrinkage and had a similar localization with PLD1 and PLD2 in dense structures, containing the trans-Golgi apparatus and actin. Disruption of the actin cytoskeleton with cytochalasin D did not induce the formation of these structures. To determine, if ARF6 selectively activated PLD1 or PLD2, wild type and mutant forms of the ARF isoform were transfected together with PLD1 or PLD2. Wild type ARF6 did not affect either PLD isozyme, but dominant active ARF6 selectively activated PLD2 and dominant negative ARF6 selectively inhibited PLD2. In contrast, dominant active ARF1 or Rac1 stimulated both PLD isozymes but the ARF1 effect on PLD2 was very small. Cytochalasin D did not affect the activation of PLD by phorbol ester. The localizations of PLD and ARF6 were also analyzed by fractionation after methyl-beta-cyclodextrin extraction to deplete cholesterol. The results showed that all PLD isoforms and ARF6 mutants existed in the membrane fraction, but only wild type ARF6 was dependent on the presence of cholesterol. These experiments showed that wild type ARF6 had a similar location with PLD isoforms on cell staining, but it did not colocalize with PLD isoforms in fractionation experiments. It is proposed that activated ARF6 translocates to the cholesterol independent microdomain and then activates PLD2 there. It is further concluded that PLD2 is selectively activated by ARF6 in vivo and that disruption of the actin cytoskeleton does not affect this activation.
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Affiliation(s)
- Masami Hiroyama
- Howard Hughes Medical Institute, Vanderbilt University School of Medicine Nashville, Tennessee 37232, USA
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22
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Voronina E, Wessel GM. βγ subunits of heterotrimeric G-proteins contribute to Ca2+ release at fertilization in the sea urchin. J Cell Sci 2004; 117:5995-6005. [PMID: 15536121 DOI: 10.1242/jcs.01518] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A cytoplasmic Ca2+ transient is required for egg activation at fertilization in all animals. The pathway leading to release of Ca2+ from the endoplasmic reticulum in echinoderms includes activation of a SRC homolog, followed by phospholipase Cγ activation, and formation of inositol trisphosphate. However, the upstream activators or modulators of this signaling pathway are not known. We recently identified four Gα subunits of heterotrimeric G-proteins present in the sea urchin egg, and here we find that activation of G-proteins of the Gαs and Gαq type, but not Gαi or Gα12 type, is required for normal Ca2+ dynamics at fertilization. The effects of these G-proteins are mediated by the Gβγ subunits, occur upstream of the cytoplasmic Ca2+ release, and influence both the amplitude of Ca2+ release and the duration of the lag phase. We propose integration of the G-protein input into the framework of signaling at sea urchin fertilization.
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Affiliation(s)
- Ekaterina Voronina
- Department of Molecular and Cell Biology and Biochemistry, Brown University, 69 Brown Street, Providence, RI 02912, USA
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Narenjkar J, Marsh SJ, Assem ESK. Inhibition of the antigen-induced activation of RBL-2H3 cells by charybdotoxin and cetiedil. Eur J Pharmacol 2004; 483:95-106. [PMID: 14729096 DOI: 10.1016/j.ejphar.2003.10.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Quinidine and Ba(2+), non-selective K(+)-channel blockers, have previously been shown to inhibit antigen-induced mediator (beta-hexosaminidase) release from RBL-2H3 cells, a mucosal-type mast cell line. We therefore used selective blockers of Ca(2+)-activated and other K(+) channels to determine if there was a role for these channels in antigen-induced mediator release. Charybdotoxin and cetiedil dose-dependently inhibited beta-hexosaminidase release with IC(50) values of 133 nM and 84 microM, respectively. Charybdotoxin also inhibited the repolarization phase of the antigen-induced biphasic change in the membrane potential (IC(50) 84 nM), antigen-stimulated 86Rb(+)-efflux and increase in free intracellular calcium, [Ca(2+)](i). Iberiotoxin, margatoxin, apamin and tetraethylammonium had no effect on beta-hexosaminidase release. These results suggest that K(+) conductances play a significant role in mediator release from RBL-2H3, that these conductances are of the intermediate conductance Ca(2+)-activated K(+) channel (IK(Ca)) type, and that they are somewhat similar to those which have been described in red blood cells, though they are much less sensitive to clotrimazole.
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Affiliation(s)
- Jamshid Narenjkar
- Department of Pharmacology, University College London, Gower St., London WC1E 6BT, UK
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24
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Jones S, Howl J. Charge delocalisation and the design of novel mastoparan analogues: enhanced cytotoxicity and secretory efficacy of [Lys5, Lys8, Aib10]MP. ACTA ACUST UNITED AC 2004; 121:121-8. [PMID: 15256282 DOI: 10.1016/j.regpep.2004.04.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Revised: 04/22/2004] [Accepted: 04/29/2004] [Indexed: 11/28/2022]
Abstract
The formation of an amphipathic helix is a major determinant of the biological activity of the tetradecapeptide mastoparan (MP). To address the functional significance of lysyl residues at positions 4, 11 and 12 of MP, we synthesised five novel analogues using sequence permutation and arginine-substitution to delocalise cationic charge. Comparative bioassays determined cytotoxicity, beta-hexoseaminidase secretory efficacy and peptide-activated extracellular receptor-stimulated kinase (ERK)1/2 phosphorylation. The monosubstitution of individual lysine residues with arginine produced differential changes to the indices of cytotoxicity and secretion indicating that these conservative substitutions are compatible with membrane translocation and the selective binding and activation of intracellular proteins. More profound changes to the predicted hydrophilic face of MP, resulting from the relocation or substitution of additional lysyl residues, enhanced both the cytotoxicity and secretory efficacy of novel peptides. Significantly, the more amphipathic peptide [Lys5, Lys8, Aib10]MP was identified to be both the most cytotoxic and the most potent secretagogue of all the peptides compared here. Charge delocalisation within the hydrophilic face of MP analogues was also compatible with peptide-induced activation of ERK1/2 phosphorylation. Our data indicate that charge delocalisation is a suitable strategy to engineer more potent analogues of MP that differentially target intracellular proteins.
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Affiliation(s)
- Sarah Jones
- Research Institute in Healthcare Science, School of Applied Sciences, University of Wolverhampton, Wulfruna Street, Wolverhampton WV1 1SB, UK
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25
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Hitomi T, Zhang J, Nicoletti LM, Grodzki ACG, Jamur MC, Oliver C, Siraganian RP. Phospholipase D1 regulates high-affinity IgE receptor-induced mast cell degranulation. Blood 2004; 104:4122-8. [PMID: 15339843 DOI: 10.1182/blood-2004-06-2091] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To investigate the role of phospholipase D (PLD) in FcepsilonRI signaling, the wild-type or the catalytically inactive forms of PLD1 or PLD2 were stably overexpressed in RBL-2H3 mast cells. FcepsilonRI stimulation resulted in the activation of both PLD1 and PLD2. However, PLD1 was the source of most of the receptor-induced PLD activity. There was enhanced FcepsilonRI-induced degranulation only in cells that overexpressed the catalytically inactive PLD1. This dominant-negative PLD1 enhanced FcepsilonRI-induced tyrosine phosphorylations of early signaling molecules such as the receptor subunits, Syk and phospholipase C-gamma which resulted in faster release of Ca(2+) from intracellular sources. Therefore, PLD1 negatively regulates signals upstream of the Ca(2+) response. However, FcepsilonRI-induced PLD activation required Syk and was downstream of the Ca(2+)response, suggesting that basal PLD1 activity rather than that activated by cell stimulation controlled these early signaling events. Dominant-negative PLD1 reduced the basal phosphatidic acid formation in unstimulated cells, which was accompanied by an increase in FcepsilonRI within the lipid rafts. These results indicate that constitutive basal PLD1 activity by regulating phosphatidic acid formation controls the early signals initiated by FcepsilonRI aggregation that lead to mast cell degranulation.
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Affiliation(s)
- Tomohiro Hitomi
- Receptors and Signal Transduction Section, Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.
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26
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Chahdi A, Sorokin A, Dunn MJ, Landry Y. The Rac/Cdc42 guanine nucleotide exchange factor beta1Pix enhances mastoparan-activated Gi-dependent pathway in mast cells. Biochem Biophys Res Commun 2004; 317:384-9. [PMID: 15063769 DOI: 10.1016/j.bbrc.2004.03.062] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2004] [Indexed: 11/20/2022]
Abstract
Carbachol stimulates granule exocytosis, phospholipase C (PLC), and phospholipase D (PLD) in RBL-2H3hm1 mast cells by a mechanism that involves Galphaq. However, mastoparan stimulates the same responses through Gi protein. Both Gi and Galphaq pathways are suppressed by Clostridium difficile toxin B, suggesting that Rac and Cdc42 small GTPases are also involved. Over-expression of beta1Pix, a guanine nucleotide exchange factor for Rac and Cdc42, enhances mastoparan-but not carbachol-induced hexosaminidase secretion and PLC and PLD activation. Furthermore, cells expressing beta1Pix exhibit elevated levels of mastoparan-stimulated IP3 production. Taken together, these findings implicate beta1Pix in regulating hexoasaminidase secretion and IP3 production in early stage upon mastoparan stimulation.
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Affiliation(s)
- Ahmed Chahdi
- Division of Nephrology and the Cardiovascular Research Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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27
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Miles GP, Samuel MA, Jones AM, Ellis BE. Mastoparan rapidly activates plant MAP kinase signaling independent of heterotrimeric G proteins. PLANT PHYSIOLOGY 2004; 134:1332-6. [PMID: 15084727 PMCID: PMC419810 DOI: 10.1104/pp.103.037275] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2003] [Revised: 12/30/2003] [Accepted: 12/30/2003] [Indexed: 05/19/2023]
Affiliation(s)
- Godfrey P Miles
- Biotechnology Laboratory, Agricultural Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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28
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Voronina E, Wessel GM. Regulatory contribution of heterotrimeric G-proteins to oocyte maturation in the sea urchin. Mech Dev 2004; 121:247-59. [PMID: 15003628 DOI: 10.1016/j.mod.2004.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Revised: 01/14/2004] [Accepted: 01/14/2004] [Indexed: 10/26/2022]
Abstract
Regulation of animal oocyte maturation is hypothesized to involve heterotrimeric G-proteins. It is difficult to test this hypothesis though without knowing what G-proteins are present in these cells and where are they localized. We set out to test the hypothesis that G-proteins regulate maturation in the sea urchin oocyte by identifying resident G-proteins in oocytes and eggs, and then investigating their function. We find four families of G-protein alpha-subunits (Galphai, Galphaq, Galphas, and Galpha12) present in both oocytes and eggs of the sea urchin. Three of them, Galphai, Galphaq, and Galphas are present on the plasma membrane of the oocyte, while the fourth is located on cytoplasmic vesicles. Upon oocyte maturation, these proteins remain in eggs, and continue to be expressed in embryonic tissues. To test the functional contribution of the G-proteins to the regulation of oocyte maturation, we employ specific intervening reagents, including antibodies and competitor peptides to each Galpha subunit, and specific Galpha toxins. We find that Gi is a main candidate for a positive regulator of sea urchin oocyte maturation. These studies provide a foundation to further test specific hypotheses of the G-protein mediated regulation of oocyte maturation, fertilization, and early development in the sea urchin.
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Affiliation(s)
- Ekaterina Voronina
- Department of Molecular and Cell Biology and Biochemistry, Brown University, 69 Brown Street, Providence, RI 02912, USA
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29
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Du G, Huang P, Liang BT, Frohman MA. Phospholipase D2 localizes to the plasma membrane and regulates angiotensin II receptor endocytosis. Mol Biol Cell 2004; 15:1024-30. [PMID: 14718562 PMCID: PMC363061 DOI: 10.1091/mbc.e03-09-0673] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Phospholipase D (PLD) is a key facilitator of multiple types of membrane vesicle trafficking events. Two PLD isoforms, PLD1 and PLD2, exist in mammals. Initial studies based on overexpression studies suggested that in resting cells, human PLD1 localized primarily to the Golgi and perinuclear vesicles in multiple cell types. In contrast, overexpressed mouse PLD2 was observed to localize primarily to the plasma membrane, although internalization on membrane vesicles was observed subsequent to serum stimulation. A recent report has suggested that the assignment of PLD2 to the plasma membrane is in error, because the endogenous isoform in rat secretory cells was imaged and found to be present primarily in the Golgi apparatus. We have reexamined this issue by using a monoclonal antibody specific for mouse PLD2, and find, as reported initially using overexpression studies, that endogenous mouse PLD2 is detected most readily at the plasma membrane in multiple cell types. In addition, we report that mouse, rat, and human PLD2 when overexpressed all similarly localize to the plasma membrane in cell lines from all three species. Finally, studies conducted using overexpression of wild-type active or dominant-negative isoforms of PLD2 and RNA interference-mediated targeting of PLD2 suggest that PLD2 functions at the plasma membrane to facilitate endocytosis of the angiotensin II type 1 receptor.
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Affiliation(s)
- Guangwei Du
- Department of Pharmacology and the Center for Developmental Genetics, University Medical Center at Stony Brook, Stony Brook, New York 11794-5140, USA
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Howl J, Jones S, Farquhar M. Intracellular Delivery of Bioactive Peptides to RBL-2H3 Cells Induces β-Hexosaminidase Secretion and Phospholipase D Activation. Chembiochem 2003; 4:1312-6. [PMID: 14661273 DOI: 10.1002/cbic.200300694] [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: 11/06/2022]
Abstract
This investigation compared the secretory efficacies of a series of peptides delivered to the cytoplasm of RBL-2H3 mast cells. Mimetic peptides, designed to target intracellular proteins that regulate cell signalling and membrane fusion, were synthesised as transportan 10 (TP10) chimeras for efficient plasma membrane translocation. Exocytosis of beta-hexosaminidase, a secretory lysosomal marker, indicated that peptides presenting sequences derived from protein kinase C (PKC; C1 H-CRRLSVEIWDWDL-NH(2)) and the CB(1) cannabinoid receptor (C3 H-RSKDLRHAFRSMFPSCE-NH(2)) induced beta-hexosaminidase secretion. Other peptide cargoes, including a Rab3A-derived sequence and a homologue of C3, were inactive in similar assays. Translocated C1 also activated phospholipase D (PLD), an enzyme intimately involved in the regulated secretory response of RBL-2H3 cells, but C1-induced secretion was not dependent upon phosphatidate synthesis. Neither down-regulation of Ca(2+)-sensitive isoforms of PKC nor the application of a selective PKC inhibitor attenuated the secretory efficacy of C1. These observations indicate that the molecular target of C1 is a protein involved in the regulated secretory pathway that is upstream of PLD but is not a PKC isoform. This study also confirmed that TP10 is a relatively inert cell-penetrating vector and is, therefore, widely suitable for studies in cells that are sensitive to peptidyl secretagogues.
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Affiliation(s)
- John Howl
- Molecular Pharmacology Group, School of Applied Sciences, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1SB, UK.
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