1
|
Tan X, Sun Y, Chen L, Hu J, Meng Y, Yuan M, Wang Q, Li S, Zheng G, Qiu Z. Caffeine Ameliorates AKT-Driven Nonalcoholic Steatohepatitis by Suppressing De Novo Lipogenesis and MyD88 Palmitoylation. J Agric Food Chem 2022; 70:6108-6122. [PMID: 35536225 DOI: 10.1021/acs.jafc.2c01013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dysregulated hepatic lipogenesis represents a promising druggable target for treating nonalcoholic steatohepatitis (NASH). This work aims to evaluate the therapeutic efficacy of caffeine in a NASH mouse model displaying increased hepatic lipogenesis driven by constitutive hepatic overexpression of the active v-akt murine thymoma viral oncogene homolog (AKT). Caffeine was administered in the AKT mice to study the efficacy in vivo. AKT-transfected and insulin-stimulated human hepatoma cells were used for in vitro experiments. The results demonstrated that caffeine ameliorated hepatic steatosis and inflammatory injury in vivo. Mechanistically, caffeine repressed the AKT/mTORC1 and SREBP-1/ACC/FASN signaling in mice and in vitro. Furthermore, caffeine impaired NF-κB activation by stabilizing IκBα, resulting in a reduction of proinflammatory mediators interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). Notably, caffeine abolished mTORC1/FASN-dependent MyD88 palmitoylation, which could be essential for its anti-inflammatory potential. Collectively, these results suggest that caffeine consumption could be advantageous in the prevention and therapy of NASH, especially in the subset accompanied by increased de novo lipogenesis.
Collapse
Affiliation(s)
- Xiangyun Tan
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Yi Sun
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Liang Chen
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Junjie Hu
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Yan Meng
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Ming Yuan
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Qi Wang
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Shan Li
- Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei University of Medicine, Shiyan 442000, People's Republic of China
| | - Guohua Zheng
- Key Laboratory of Chinese Medicine Resource and Compound Prescription, Ministry of Education, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| | - Zhenpeng Qiu
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
- Hubei Key Laboratory of Resources and Chemistry of Chinese Medicine, Hubei University of Chinese Medicine, Wuhan 430065, People's Republic of China
| |
Collapse
|
2
|
Rech L, Abdellatif M, Pöttler M, Stangl V, Mabotuwana N, Hardy S, Rainer PP. Small molecule STING inhibition improves myocardial infarction remodeling. Life Sci 2022; 291:120263. [PMID: 34971697 DOI: 10.1016/j.lfs.2021.120263] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/07/2021] [Accepted: 12/18/2021] [Indexed: 01/31/2023]
Abstract
AIMS Myocardial infarction (MI) is a major global cause of death. Massive cell death leads to inflammation, which is necessary for ensuing wound healing. Extensive inflammation, however, promotes infarct expansion and adverse remodeling. The DNA sensing receptor cyclic GMP-AMP synthase and its downstream signaling effector stimulator of interferon genes (cGAS-STING) is central in innate immune reactions in infections or autoimmunity. Cytosolic double-strand DNA activates the pathway and down-stream inflammatory responses. Recent papers demonstrated that this pathway is also active following MI and that its genetic targeting improves outcome. Thus, we investigated if pharmacologic pathway inhibition is protective after MI in order to test its translational potential. MAIN METHODS We investigated novel and selective small-molecule STING inhibitors that inhibit STING palmitoylation and multimerization and thereby downstream pathway activation in a preclinical murine MI model. We assessed structural and functional cardiac remodeling, infarct expansion and fibrosis, as well as cardiomyocyte hypertrophy and the expression of inflammatory genes. KEY FINDINGS Pharmacologic STING inhibition did not reduce mortality due to myocardial rupture in non-reperfused MI. Infarct size at day one was comparable. However, three weeks of pharmacologic STING inhibition after reperfused MI decreased infarct expansion and scarring, increased left ventricular systolic function to levels approaching normal values, and reduced myocardial hypertrophy. SIGNIFICANCE Selective small-molecule STING inhibition after myocardial infarction has the potential to improve wound healing responses and pathological remodeling and thereby attenuate the development of ischemic heart failure.
Collapse
Affiliation(s)
- Lavinia Rech
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Mahmoud Abdellatif
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Maria Pöttler
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Verena Stangl
- Diagnostic and Research Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Nishani Mabotuwana
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; School of Medicine and Public Health, The University of Newcastle, Callaghan, Australia; Hunter Medical Research Institute, New Lambton Heights, Australia
| | - Sean Hardy
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; School of Medicine and Public Health, The University of Newcastle, Callaghan, Australia; Hunter Medical Research Institute, New Lambton Heights, Australia
| | - Peter P Rainer
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria.
| |
Collapse
|
3
|
Schlott AC, Knuepfer E, Green JL, Hobson P, Borg AJ, Morales-Sanfrutos J, Perrin AJ, Maclachlan C, Collinson LM, Snijders AP, Tate EW, Holder AA. Inhibition of protein N-myristoylation blocks Plasmodium falciparum intraerythrocytic development, egress and invasion. PLoS Biol 2021; 19:e3001408. [PMID: 34695132 PMCID: PMC8544853 DOI: 10.1371/journal.pbio.3001408] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/07/2021] [Indexed: 11/29/2022] Open
Abstract
We have combined chemical biology and genetic modification approaches to investigate the importance of protein myristoylation in the human malaria parasite, Plasmodium falciparum. Parasite treatment during schizogony in the last 10 to 15 hours of the erythrocytic cycle with IMP-1002, an inhibitor of N-myristoyl transferase (NMT), led to a significant blockade in parasite egress from the infected erythrocyte. Two rhoptry proteins were mislocalized in the cell, suggesting that rhoptry function is disrupted. We identified 16 NMT substrates for which myristoylation was significantly reduced by NMT inhibitor (NMTi) treatment, and, of these, 6 proteins were substantially reduced in abundance. In a viability screen, we showed that for 4 of these proteins replacement of the N-terminal glycine with alanine to prevent myristoylation had a substantial effect on parasite fitness. In detailed studies of one NMT substrate, glideosome-associated protein 45 (GAP45), loss of myristoylation had no impact on protein location or glideosome assembly, in contrast to the disruption caused by GAP45 gene deletion, but GAP45 myristoylation was essential for erythrocyte invasion. Therefore, there are at least 3 mechanisms by which inhibition of NMT can disrupt parasite development and growth: early in parasite development, leading to the inhibition of schizogony and formation of “pseudoschizonts,” which has been described previously; at the end of schizogony, with disruption of rhoptry formation, merozoite development and egress from the infected erythrocyte; and at invasion, when impairment of motor complex function prevents invasion of new erythrocytes. These results underline the importance of P. falciparum NMT as a drug target because of the pleiotropic effect of its inhibition. Understanding the essential factors needed for malaria parasite development could help us find new therapeutic targets. This study reveals that N-myristoylation is a posttranslational modification of proteins essential for the parasites’ growth and their invasion of red blood cells.
Collapse
Affiliation(s)
- Anja C. Schlott
- Malaria Parasitology Laboratory, Francis Crick Institute, London, United Kingdom
- Molecular Sciences Research Hub, Imperial College, London, United Kingdom
| | - Ellen Knuepfer
- Malaria Parasitology Laboratory, Francis Crick Institute, London, United Kingdom
- Department of Pathobiology and Population Sciences, The Royal Veterinary College, Hatfield, United Kingdom
| | - Judith L. Green
- Malaria Parasitology Laboratory, Francis Crick Institute, London, United Kingdom
| | - Philip Hobson
- Flow Cytometry Science Technology Platform, Francis Crick Institute, London, United Kingdom
| | - Aaron J. Borg
- Mass Spectrometry Proteomics Science Technology Platform, Francis Crick Institute, London, United Kingdom
| | | | - Abigail J. Perrin
- Malaria Biochemistry Laboratory, Francis Crick Institute, London, United Kingdom
| | - Catherine Maclachlan
- Electron Microscopy Science Technology Platform, Francis Crick Institute, London, United Kingdom
| | - Lucy M. Collinson
- Electron Microscopy Science Technology Platform, Francis Crick Institute, London, United Kingdom
| | - Ambrosius P. Snijders
- Mass Spectrometry Proteomics Science Technology Platform, Francis Crick Institute, London, United Kingdom
| | - Edward W. Tate
- Molecular Sciences Research Hub, Imperial College, London, United Kingdom
- Francis Crick Institute, London, United Kingdom
- * E-mail: (EWT); (AAH)
| | - Anthony A. Holder
- Malaria Parasitology Laboratory, Francis Crick Institute, London, United Kingdom
- * E-mail: (EWT); (AAH)
| |
Collapse
|
4
|
Laudette M, Sainte-Marie Y, Cousin G, Bergonnier D, Belhabib I, Brun S, Formoso K, Laib L, Tortosa F, Bergoglio C, Marcheix B, Borén J, Lairez O, Fauconnier J, Lucas A, Mialet-Perez J, Moro C, Lezoualc'h F. Cyclic AMP-binding protein Epac1 acts as a metabolic sensor to promote cardiomyocyte lipotoxicity. Cell Death Dis 2021; 12:824. [PMID: 34471096 PMCID: PMC8410846 DOI: 10.1038/s41419-021-04113-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/28/2021] [Accepted: 08/16/2021] [Indexed: 01/21/2023]
Abstract
Cyclic adenosine monophosphate (cAMP) is a master regulator of mitochondrial metabolism but its precise mechanism of action yet remains unclear. Here, we found that a dietary saturated fatty acid (FA), palmitate increased intracellular cAMP synthesis through the palmitoylation of soluble adenylyl cyclase in cardiomyocytes. cAMP further induced exchange protein directly activated by cyclic AMP 1 (Epac1) activation, which was upregulated in the myocardium of obese patients. Epac1 enhanced the activity of a key enzyme regulating mitochondrial FA uptake, carnitine palmitoyltransferase 1. Consistently, pharmacological or genetic Epac1 inhibition prevented lipid overload, increased FA oxidation (FAO), and protected against mitochondrial dysfunction in cardiomyocytes. In addition, analysis of Epac1 phosphoproteome led us to identify two key mitochondrial enzymes of the the β-oxidation cycle as targets of Epac1, the long-chain FA acyl-CoA dehydrogenase (ACADL) and the 3-ketoacyl-CoA thiolase (3-KAT). Epac1 formed molecular complexes with the Ca2+/calmodulin-dependent protein kinase II (CaMKII), which phosphorylated ACADL and 3-KAT at specific amino acid residues to decrease lipid oxidation. The Epac1-CaMKII axis also interacted with the α subunit of ATP synthase, thereby further impairing mitochondrial energetics. Altogether, these findings indicate that Epac1 disrupts the balance between mitochondrial FA uptake and oxidation leading to lipid accumulation and mitochondrial dysfunction, and ultimately cardiomyocyte death.
Collapse
Affiliation(s)
- Marion Laudette
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Yannis Sainte-Marie
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Grégoire Cousin
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
- Centre Hospitalier Universitaire de Toulouse Rangueil, Toulouse, France
| | - Dorian Bergonnier
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Ismahane Belhabib
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Stéphanie Brun
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
- Centre Hospitalier Universitaire de Toulouse Rangueil, Toulouse, France
| | - Karina Formoso
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Loubna Laib
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Florence Tortosa
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Camille Bergoglio
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Bertrand Marcheix
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
- Centre Hospitalier Universitaire de Toulouse Rangueil, Toulouse, France
| | - Jan Borén
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Olivier Lairez
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
- Centre Hospitalier Universitaire de Toulouse Rangueil, Toulouse, France
| | - Jérémy Fauconnier
- PHYMEDEXP, Université de Montpellier, CNRS, INSERM, CHRU Montpellier, Montpellier, France
| | - Alexandre Lucas
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Jeanne Mialet-Perez
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Cédric Moro
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France
| | - Frank Lezoualc'h
- Institut des Maladies Métaboliques et Cardiovasculaires, Inserm, Université Paul Sabatier, UMR 1297-I2MC, Toulouse, France.
| |
Collapse
|
5
|
Lemarié FL, Caron NS, Sanders SS, Schmidt ME, Nguyen YTN, Ko S, Xu X, Pouladi MA, Martin DDO, Hayden MR. Rescue of aberrant huntingtin palmitoylation ameliorates mutant huntingtin-induced toxicity. Neurobiol Dis 2021; 158:105479. [PMID: 34390831 DOI: 10.1016/j.nbd.2021.105479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/14/2023] Open
Abstract
Huntington disease (HD) is a neurodegenerative disorder caused by a CAG expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. HTT is subject to multiple post-translational modifications (PTMs) that regulate its cellular function. Mutating specific PTM sites within mutant HTT (mHTT) in HD mouse models can modulate disease phenotypes, highlighting the key role of HTT PTMs in the pathogenesis of HD. These findings have led to increased interest in developing small molecules to modulate HTT PTMs in order to decrease mHTT toxicity. However, the therapeutic efficacy of pharmacological modulation of HTT PTMs in preclinical HD models remains largely unknown. HTT is palmitoylated at cysteine 214 by the huntingtin-interacting protein 14 (HIP14 or ZDHHC17) and 14-like (HIP14L or ZDHHC13) acyltransferases. Here, we assessed if HTT palmitoylation should be regarded as a therapeutic target to treat HD by (1) investigating palmitoylation dysregulation in rodent and human HD model systems, (2) measuring the impact of mHTT-lowering therapy on brain palmitoylation, and (3) evaluating if HTT palmitoylation can be pharmacologically modulated. We show that palmitoylation of mHTT and some HIP14/HIP14L-substrates is decreased early in multiple HD mouse models, and that mHTT palmitoylation decreases further with aging. Lowering mHTT in the brain of YAC128 mice is not sufficient to rescue aberrant palmitoylation. However, we demonstrate that mHTT palmitoylation can be normalized in COS-7 cells, in YAC128 cortico-striatal primary neurons and HD patient-derived lymphoblasts using an acyl-protein thioesterase (APT) inhibitor. Moreover, we show that modulating palmitoylation reduces mHTT aggregation and mHTT-induced cytotoxicity in COS-7 cells and YAC128 neurons.
Collapse
Affiliation(s)
- Fanny L Lemarié
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Nicholas S Caron
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada; Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Mandi E Schmidt
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Yen T N Nguyen
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Seunghyun Ko
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada
| | - Xiaohong Xu
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China; Translational Laboratory in Genetic Medicine, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Mahmoud A Pouladi
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada; Translational Laboratory in Genetic Medicine, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada; Department of Biology, University of Waterloo, Waterloo, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, Canada.
| |
Collapse
|
6
|
Williams CG, Jureka AS, Silvas JA, Nicolini AM, Chvatal SA, Carlson-Stevermer J, Oki J, Holden K, Basler CF. Inhibitors of VPS34 and fatty-acid metabolism suppress SARS-CoV-2 replication. Cell Rep 2021; 36:109479. [PMID: 34320401 PMCID: PMC8289695 DOI: 10.1016/j.celrep.2021.109479] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 03/19/2021] [Accepted: 07/12/2021] [Indexed: 02/06/2023] Open
Abstract
Coronaviruses rely on host membranes for entry, establishment of replication centers, and egress. Compounds targeting cellular membrane biology and lipid biosynthetic pathways have previously shown promise as antivirals and are actively being pursued as treatments for other conditions. Here, we test small molecule inhibitors that target the PI3 kinase VPS34 or fatty acid metabolism for anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) activity. Our studies determine that compounds targeting VPS34 are potent SARS-CoV-2 inhibitors. Mechanistic studies with compounds targeting multiple steps up- and downstream of fatty acid synthase (FASN) identify the importance of triacylglycerol production and protein palmitoylation as requirements for efficient viral RNA synthesis and infectious virus production. Further, FASN knockout results in significantly impaired SARS-CoV-2 replication that can be rescued with fatty acid supplementation. Together, these studies clarify roles for VPS34 and fatty acid metabolism in SARS-CoV-2 replication and identify promising avenues for the development of countermeasures against SARS-CoV-2.
Collapse
Affiliation(s)
- Caroline G Williams
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Alexander S Jureka
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Jesus A Silvas
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | | | | | | | | | | | - Christopher F Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA.
| |
Collapse
|
7
|
Song J, Xia XY, Gao T, Yuan CM, Lu XT, Wang LP, Zhang HF. Palmitoylation of AMPA Receptors is Involved in the Inhibition of Hippocampal Long-term Potentiation by Aluminum Exposure in Rats. Biomed Environ Sci 2020; 33:959-963. [PMID: 33472739 DOI: 10.3967/bes2020.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/22/2020] [Indexed: 06/12/2023]
Affiliation(s)
- Jing Song
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| | - Xin Yu Xia
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| | - Ting Gao
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| | - Chun Man Yuan
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| | - Xiao Ting Lu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| | - Lin Ping Wang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| | - Hui Fang Zhang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, Shanxi, China
| |
Collapse
|
8
|
Sosa LDV, Petiti JP, Picech F, Chumpen S, Nicola JP, Perez P, De Paul A, Valdez-Taubas J, Gutierrez S, Torres AI. The ERα membrane pool modulates the proliferation of pituitary tumours. J Endocrinol 2019; 240:229-241. [PMID: 30400032 DOI: 10.1530/joe-18-0418] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 10/31/2018] [Indexed: 01/22/2023]
Abstract
The molecular mechanisms underlying the ERα nuclear/cytoplasmic pool that modulates pituitary cell proliferation have been widely described, but it is still not clear how ERα is targeted to the plasma membrane. The aim of this study was to analyse ERα palmitoylation and the plasma membrane ERα (mERα) pool, and their participation in E2-triggered membrane-initiated signalling in normal and pituitary tumour cell growth. Cell cultures were prepared from anterior pituitaries of female Wistar rats and tumour GH3 cells, and treated with 10 nM of oestradiol (E2). The basal expression of ERα was higher in tumour GH3 than in normal pituitary cells. Full-length palmitoylated ERα was observed in normal and pituitary tumour cells, demonstrating that E2 stimulation increased both, ERα in plasma membrane and ERα and caveolin-1 interaction after short-term treatment. In addition, the Dhhc7 and Dhhc21 palmitoylases were negatively regulated after sustained stimulation of E2 for 3 h. Although the uptake of BrdU into the nucleus in normal pituitary cells was not modified by E2, a significant increase in the GH3 tumoural cell, as well as ERK1/2 activation, with this effect being mimicked by PPT, a selective antagonist of ERα. These proliferative effects were blocked by ICI 182780 and the global inhibitor of palmitoylation. These findings indicate that ERα palmitoylation modulated the mERα pool and consequently the ERK1/2 pathway, thereby contributing to pituitary tumour cell proliferation. These results suggest that the plasma membrane ERα pool might be related to the proliferative behaviour of prolactinoma and may be a marker of pituitary tumour growth.
Collapse
Affiliation(s)
- Liliana Del V Sosa
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| | - Juan P Petiti
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| | - Florencia Picech
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| | - Sabrina Chumpen
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, CIQUIBIC-CONICET, Cordoba, Argentina
| | - Juan P Nicola
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, CIBICI-CONICET, Cordoba, Argentina
| | - Pablo Perez
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| | - Ana De Paul
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| | - Javier Valdez-Taubas
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, CIQUIBIC-CONICET, Cordoba, Argentina
| | - Silvina Gutierrez
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| | - Alicia I Torres
- Universidad Nacional de Córdoba, Facultad de Ciencias Médicas, Centro de Microscopía Electrónica - Consejo Nacional de Investigaciones Científicas Técnicas (CONICET) Instituto de Investigaciones en Ciencias de la Salud, Córdoba, Argentina
| |
Collapse
|
9
|
Kharbanda A, Runkle K, Wang W, Witze ES. Induced sensitivity to EGFR inhibitors is mediated by palmitoylated cysteine 1025 of EGFR and requires oncogenic Kras. Biochem Biophys Res Commun 2017; 493:213-219. [PMID: 28899783 DOI: 10.1016/j.bbrc.2017.09.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 09/09/2017] [Indexed: 12/13/2022]
Abstract
Currently, there are no effective therapeutic strategies targeting Kras driven cancers, and therefore, identifying new targeted therapies and overcoming drug resistance have become paramount for effective long-term cancer therapy. We have found that reducing expression of the palmitoyl transferase DHHC20 increases cell death induced by the EGFR inhibitor gefitinib in Kras and EGFR mutant cell lines, but not MCF7 cells harboring wildtype Kras. We show that the increased gefitinib sensitivity in cancer cells induced by DHHC20 inhibition is mediated directly through loss of palmitoylation on a previously identified cysteine residue in the C-terminal tail of EGFR. We utilized an EGFR point mutant in which the palmitoylated cysteine 1025 is mutated to alanine (EGFRC1025A), that results in receptor activation. Expression of the EGFR mutant alone in NIH3T3 cells does not increase sensitivity to gefitinib-induced cell death. However, when EGFRC1025A is expressed in cells expressing activated KrasG12V, EGFR inhibitor induced cell death is increased. Surprisingly, lung cancer cells harboring the EGFR inhibitor resistant mutation, T790M, become sensitive to EGFR inhibitor treatment when DHHC20 is inhibited. Finally, the small molecule, 2-bromopalmitate, which has been shown to inhibit palmitoyl transferases, acts synergistically with gefitinib to induce cell death in the gefitinib resistant cell line NCI-H1975.
Collapse
Affiliation(s)
- Akriti Kharbanda
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Kristin Runkle
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Wei Wang
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Eric S Witze
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, United States; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, United States; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
| |
Collapse
|
10
|
Lanyon-Hogg T, Patel NV, Ritzefeld M, Boxall KJ, Burke R, Blagg J, Magee AI, Tate EW. Microfluidic Mobility Shift Assay for Real-Time Analysis of Peptide N-Palmitoylation. SLAS Discov 2017; 22:418-424. [PMID: 28296537 PMCID: PMC5453399 DOI: 10.1177/2472555216689529] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/24/2016] [Accepted: 12/27/2016] [Indexed: 02/06/2023]
Abstract
The Hedgehog pathway is a key developmental signaling pathway but is also implicated in many types of cancer. The extracellular signaling protein Sonic hedgehog (Shh) requires dual lipidation for functional signaling, whereby N-terminal palmitoylation is performed by the enzyme Hedgehog acyltransferase (Hhat). Hhat is an attractive target for small-molecule inhibition to arrest Hedgehog signaling, and methods for assaying Hhat activity are central to understanding its function. However, all existing assays to quantify lipidation of peptides suffer limitations, such as safety hazards, high costs, extensive manual handling, restriction to stopped-assay measurements, or indirect assessment of lipidation. To address these limitations, we developed a microfluidic mobility shift assay (MSA) to analyze Shh palmitoylation. MSA allowed separation of fluorescently labeled Shh amine-substrate and palmitoylated Shh amide-product peptides based on differences in charge and hydrodynamic radius, coupled with online fluorescence intensity measurements for quantification. The MSA format was employed to study Hhat-catalyzed reactions, investigate Hhat kinetics, and determine small-molecule inhibitor IC50 values. Both real-time and stopped assays were performed, with the latter achieved via addition of excess unlabeled Shh peptide. The MSA format therefore allows direct and real-time fluorescence-based measurement of acylation and represents a powerful alternative technique in the study of N-lipidation.
Collapse
Affiliation(s)
| | - Neki V. Patel
- Department of Chemistry, Imperial College London, London, UK
| | | | - Katherine J. Boxall
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, UK
| | - Rosemary Burke
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, UK
| | - Julian Blagg
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, UK
| | - Anthony I. Magee
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, London, UK
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, London, UK
| |
Collapse
|
11
|
Rodgers U, Lanyon-Hogg T, Masumoto N, Ritzefeld M, Burke R, Blagg J, Magee AI, Tate EW. Characterization of Hedgehog Acyltransferase Inhibitors Identifies a Small Molecule Probe for Hedgehog Signaling by Cancer Cells. ACS Chem Biol 2016; 11:3256-3262. [PMID: 27779865 PMCID: PMC5349656 DOI: 10.1021/acschembio.6b00896] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/13/2016] [Indexed: 01/01/2023]
Abstract
The Sonic Hedgehog (Shh) signaling pathway plays a critical role during embryonic development and cancer progression. N-terminal palmitoylation of Shh by Hedgehog acyltransferase (Hhat) is essential for efficient signaling, raising interest in Hhat as a novel drug target. A recently identified series of dihydrothienopyridines has been proposed to function via this mode of action; however, the lead compound in this series (RUSKI-43) was subsequently shown to possess cytotoxic activity unrelated to canonical Shh signaling. To identify a selective chemical probe for cellular studies, we profiled three RUSKI compounds in orthogonal cell-based assays. We found that RUSKI-43 exhibits off-target cytotoxicity, masking its effect on Hhat-dependent signaling, hence results obtained with this compound in cells should be treated with caution. In contrast, RUSKI-201 showed no off-target cytotoxicity, and quantitative whole-proteome palmitoylation profiling with a bioorthogonal alkyne-palmitate reporter demonstrated specific inhibition of Hhat in cells. RUSKI-201 is the first selective Hhat chemical probe in cells and should be used in future studies of Hhat catalytic function.
Collapse
Affiliation(s)
- Ursula
R. Rodgers
- Molecular
Medicine Section, National Heart & Lung
Institute, Imperial College London, London SW7 2AZ, United
Kingdom
| | - Thomas Lanyon-Hogg
- Department
of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
| | - Naoko Masumoto
- Department
of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
| | - Markus Ritzefeld
- Department
of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
| | - Rosemary Burke
- Cancer
Research UK Cancer Therapeutics Unit, The
Institute of Cancer Research, London, SW7 3RP, United Kingdom
| | - Julian Blagg
- Cancer
Research UK Cancer Therapeutics Unit, The
Institute of Cancer Research, London, SW7 3RP, United Kingdom
| | - Anthony I. Magee
- Molecular
Medicine Section, National Heart & Lung
Institute, Imperial College London, London SW7 2AZ, United
Kingdom
| | - Edward W. Tate
- Department
of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
| |
Collapse
|
12
|
Abstract
Macroautophagy (hereafter referred to as autophagy) is a degradation pathway that delivers cytoplasmic materials to lysosomes via double-membraned vesicles designated autophagosomes. Cytoplasmic constituents are sequestered into autophagosomes, which subsequently fuse with lysosomes, where the cargo is degraded. Autophagy is a crucial mechanism involved in many aspects of cell function, including cellular metabolism and energy balance; alterations in autophagy have been linked to various human pathological processes. Thus, methods that accurately measure autophagic activity are necessary. In this unit, we introduce several approaches to analyze autophagy in mammalian cells, including immunoblotting analysis of LC3 and p62, detection of autophagosome formation by fluorescence microscopy, and monitoring autophagosome maturation by tandem mRFP-GFP fluorescence microscopy. Overall, we recommend a combined use of multiple methods to accurately assess the autophagic activity in any given biological setting. © 2016 by John Wiley & Sons, Inc.
Collapse
Affiliation(s)
- Ziyan Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Rajat Singh
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
- Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
- Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| |
Collapse
|
13
|
Ohol YM, Wang Z, Kemble G, Duke G. Direct Inhibition of Cellular Fatty Acid Synthase Impairs Replication of Respiratory Syncytial Virus and Other Respiratory Viruses. PLoS One 2015; 10:e0144648. [PMID: 26659560 PMCID: PMC4684246 DOI: 10.1371/journal.pone.0144648] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 11/20/2015] [Indexed: 02/06/2023] Open
Abstract
Fatty acid synthase (FASN) catalyzes the de novo synthesis of palmitate, a fatty acid utilized for synthesis of more complex fatty acids, plasma membrane structure, and post-translational palmitoylation of host and viral proteins. We have developed a potent inhibitor of FASN (TVB-3166) that reduces the production of respiratory syncytial virus (RSV) progeny in vitro from infected human lung epithelial cells (A549) and in vivo from mice challenged intranasally with RSV. Addition of TVB-3166 to the culture medium of RSV-infected A549 cells reduces viral spread without inducing cytopathic effects. The antiviral effect of the FASN inhibitor is a direct consequence of reducing de novo palmitate synthesis; similar doses are required for both antiviral activity and inhibition of palmitate production, and the addition of exogenous palmitate to TVB-3166-treated cells restores RSV production. TVB-3166 has minimal effect on RSV entry but significantly reduces viral RNA replication, protein levels, viral particle formation and infectivity of released viral particles. TVB-3166 substantially impacts viral replication, reducing production of infectious progeny 250-fold. In vivo, oral administration of TVB-3166 to RSV-A (Long)-infected BALB/c mice on normal chow, starting either on the day of infection or one day post-infection, reduces RSV lung titers 21-fold and 9-fold respectively. Further, TVB-3166 also inhibits the production of RSV B, human parainfluenza 3 (PIV3), and human rhinovirus 16 (HRV16) progeny from A549, HEp2 and HeLa cells respectively. Thus, inhibition of FASN and palmitate synthesis by TVB-3166 significantly reduces RSV progeny both in vitro and in vivo and has broad-spectrum activity against other respiratory viruses. FASN inhibition may alter the composition of regions of the host cell membrane where RSV assembly or replication occurs, or change the membrane composition of RSV progeny particles, decreasing their infectivity.
Collapse
Affiliation(s)
- Yamini M. Ohol
- 3-V Biosciences, Menlo Park, California, United States of America
| | - Zhaoti Wang
- 3-V Biosciences, Menlo Park, California, United States of America
| | - George Kemble
- 3-V Biosciences, Menlo Park, California, United States of America
| | - Gregory Duke
- 3-V Biosciences, Menlo Park, California, United States of America
- * E-mail:
| |
Collapse
|
14
|
Lanyon-Hogg T, Masumoto N, Bodakh G, Konitsiotis AD, Thinon E, Rodgers UR, Owens RJ, Magee AI, Tate EW. Click chemistry armed enzyme-linked immunosorbent assay to measure palmitoylation by hedgehog acyltransferase. Anal Biochem 2015; 490:66-72. [PMID: 26334609 PMCID: PMC4615133 DOI: 10.1016/j.ab.2015.08.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022]
Abstract
Hedgehog signaling is critical for correct embryogenesis and tissue development. However, on maturation, signaling is also found to be aberrantly activated in many cancers. Palmitoylation of the secreted signaling protein sonic hedgehog (Shh) by the enzyme hedgehog acyltransferase (Hhat) is required for functional signaling. To quantify this important posttranslational modification, many in vitro Shh palmitoylation assays employ radiolabeled fatty acids, which have limitations in terms of cost and safety. Here we present a click chemistry armed enzyme-linked immunosorbent assay (click-ELISA) for assessment of Hhat activity through acylation of biotinylated Shh peptide with an alkyne-tagged palmitoyl-CoA (coenzyme A) analogue. Click chemistry functionalization of the alkyne tag with azido-FLAG peptide allows analysis through an ELISA protocol and colorimetric readout. This assay format identified the detergent n-dodecyl β-d-maltopyranoside as an improved solubilizing agent for Hhat activity. Quantification of the potency of RU-SKI small molecule Hhat inhibitors by click-ELISA indicated IC50 values in the low- or sub-micromolar range. A stopped assay format was also employed that allows measurement of Hhat kinetic parameters where saturating substrate concentrations exceed the binding capacity of the streptavidin-coated plate. Therefore, click-ELISA represents a nonradioactive method for assessing protein palmitoylation in vitro that is readily expandable to other classes of protein lipidation.
Collapse
Affiliation(s)
- Thomas Lanyon-Hogg
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - Naoko Masumoto
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - George Bodakh
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - Antonio D Konitsiotis
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington SW7 2AZ, UK
| | - Emmanuelle Thinon
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK
| | - Ursula R Rodgers
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington SW7 2AZ, UK
| | - Raymond J Owens
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK; OPPF-UK, The Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell, Oxfordshire, OX11 0FA, UK
| | - Anthony I Magee
- Molecular Medicine Section, National Heart & Lung Institute, Imperial College London, South Kensington SW7 2AZ, UK.
| | - Edward W Tate
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, South Kensington SW7 2AZ, UK.
| |
Collapse
|
15
|
Kay HY, Greene DL, Kang S, Kosenko A, Hoshi N. M-current preservation contributes to anticonvulsant effects of valproic acid. J Clin Invest 2015; 125:3904-14. [PMID: 26348896 DOI: 10.1172/jci79727] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 07/30/2015] [Indexed: 01/04/2023] Open
Abstract
Valproic acid (VPA) has been widely used for decades to treat epilepsy; however, its mechanism of action remains poorly understood. Here, we report that the anticonvulsant effects of nonacute VPA treatment involve preservation of the M-current, a low-threshold noninactivating potassium current, during seizures. In a wide variety of neurons, activation of Gq-coupled receptors, such as the m1 muscarinic acetylcholine receptor, suppresses the M-current and induces hyperexcitability. We demonstrated that VPA treatment disrupts muscarinic suppression of the M-current and prevents resultant agonist-induced neuronal hyperexcitability. We also determined that VPA treatment interferes with M-channel signaling by inhibiting palmitoylation of a signaling scaffold protein, AKAP79/150, in cultured neurons. In a kainate-induced murine seizure model, administration of a dose of an M-channel inhibitor that did not affect kainate-induced seizure transiently eliminated the anticonvulsant effects of VPA. Retigabine, an M-channel opener that does not open receptor-suppressed M-channels, provided anticonvulsant effects only when administered prior to seizure induction in control animals. In contrast, treatment of VPA-treated mice with retigabine induced anticonvulsant effects even when administered after seizure induction. Together, these results suggest that receptor-induced M-current suppression plays a role in the pathophysiology of seizures and that preservation of the M-current during seizures has potential as an effective therapeutic strategy.
Collapse
|
16
|
Deng Q, Waxse B, Riquelme D, Zhang J, Aguilera G. Helix 8 of the ligand binding domain of the glucocorticoid receptor (GR) is essential for ligand binding. Mol Cell Endocrinol 2015; 408:23-32. [PMID: 25676569 PMCID: PMC4417367 DOI: 10.1016/j.mce.2015.01.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 01/16/2015] [Accepted: 01/30/2015] [Indexed: 12/20/2022]
Abstract
Membrane association of estrogen receptors (ER) depends on cysteine palmitoylation and two leucines in the ligand binding domain (LBD), conserved in most steroid receptors. The role of this region, corresponding to helix 8 of the glucocorticoid receptor (GR) LBD, on membrane association of GR was studied in 4B cells, expressing endogenous GR, and Cos-7 cells transfected EGFP-GR constructs. 4B cells preloaded with radiolabeled palmitic acid showed no radioactivity incorporation into immunoprecipitated GR. Moreover, mutation C683A (corresponding to ER palmitoylation site) did not affect corticosterone-induced membrane association of GR. Mutations L687-690A, L682A, E680G and K685G prevented membrane and also nuclear localization through reduced ligand binding. L687-690A mutation decreased association of GR with heat shock protein 90 and transcriptional activity, without overt effects on receptor protein stability. The data demonstrate that palmitoylation does not mediate membrane association of GR, but that the region 680-690 (helix 8) is critical for ligand binding and receptor function.
Collapse
Affiliation(s)
- Qiong Deng
- Section on Endocrine Physiology, PDEGEN, NICHD, NIH, Bethesda, Maryland, USA; College of Animal Sciences, Jilin University, China
| | - Bennett Waxse
- Section on Organelle Biology, CBMP, NICHD, NIH, Bethesda, Maryland, USA
| | - Denise Riquelme
- Section on Endocrine Physiology, PDEGEN, NICHD, NIH, Bethesda, Maryland, USA
| | - Jiabao Zhang
- College of Animal Sciences, Jilin University, China
| | - Greti Aguilera
- Section on Endocrine Physiology, PDEGEN, NICHD, NIH, Bethesda, Maryland, USA.
| |
Collapse
|
17
|
Milde S, Coleman MP. Identification of palmitoyltransferase and thioesterase enzymes that control the subcellular localization of axon survival factor nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2). J Biol Chem 2014; 289:32858-70. [PMID: 25271157 PMCID: PMC4239634 DOI: 10.1074/jbc.m114.582338] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 09/29/2014] [Indexed: 01/04/2023] Open
Abstract
The NAD-synthesizing enzyme nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) is a critical survival factor for axons and its constant supply from neuronal cell bodies into axons is required for axon survival in primary culture neurites and axon extension in vivo. Recently, we showed that palmitoylation is necessary to target NMNAT2 to post-Golgi vesicles, thereby influencing its protein turnover and axon protective capacity. Here we find that NMNAT2 is a substrate for cytosolic thioesterases APT1 and APT2 and that palmitoylation/depalmitoylation dynamics are on a time scale similar to its short half-life. Interestingly, however, depalmitoylation does not release NMNAT2 from membranes. The mechanism of palmitoylation-independent membrane attachment appears to be mediated by the same minimal domain required for palmitoylation itself. Furthermore, we identify several zDHHC palmitoyltransferases that influence NMNAT2 palmitoylation and subcellular localization, among which a role for zDHHC17 (HIP14) in neuronal NMNAT2 palmitoylation is best supported by our data. These findings shed light on the enzymatic regulation of NMNAT2 palmitoylation and highlight individual thioesterases and palmitoyltransferases as potential targets to modulate NMNAT2-dependent axon survival.
Collapse
Affiliation(s)
- Stefan Milde
- From the Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Michael P Coleman
- From the Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| |
Collapse
|
18
|
Henry SC, Schmidt EA, Fessler MB, Taylor GA. Palmitoylation of the immunity related GTPase, Irgm1: impact on membrane localization and ability to promote mitochondrial fission. PLoS One 2014; 9:e95021. [PMID: 24751652 PMCID: PMC3994021 DOI: 10.1371/journal.pone.0095021] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/22/2014] [Indexed: 12/01/2022] Open
Abstract
The Immunity-Related GTPases (IRG) are a family of large GTPases that mediate innate immune responses. Irgm1 is particularly critical for immunity to bacteria and protozoa, and for inflammatory homeostasis in the intestine. Although precise functions for Irgm1 have not been identified, prior studies have suggested roles in autophagy/mitophagy, phagosome remodeling, cell motility, and regulating the activity of other IRG proteins. These functions ostensibly hinge on the ability of Irgm1 to localize to intracellular membranes, such as those of the Golgi apparatus and mitochondria. Previously, it has been shown that an amphipathic helix, the αK helix, in the C-terminal portion of the protein partially mediates membrane binding. However, in absence of αK, there is still substantial binding of Irgm1 to cellular membranes, suggesting the presence of other membrane binding motifs. In the current work, an additional membrane localization motif was found in the form of palmitoylation at a cluster of cysteines near the αK. An Irgm1 mutant possessing alanine to cysteine substitutions at these amino acids demonstrated little residual palmitoylation, yet it displayed only a small decrease in localization to the Golgi and mitochondria. In contrast, a mutant containing the palmitoylation mutations in combination with mutations disrupting the amphipathic character of the αK displayed a complete loss of apparent localization to the Golgi and mitochondria, as well as an overall loss of association with cellular membranes in general. Additionally, Irgm1 was found to promote mitochondrial fission, and this function was undermined in Irgm1 mutants lacking the palmitoylation domain, and to a greater extent in those lacking the αK, or the αK and palmitoylation domains combined. Our data suggest that palmitoylation together with the αK helix firmly anchor Irgm1 in the Golgi and mitochondria, thus facilitating function of the protein.
Collapse
Affiliation(s)
- Stanley C. Henry
- Geriatric Research, Education, and Clinical Center, VA Medical Center, Durham, North Carolina, United States of America
| | - Elyse A. Schmidt
- Departments of Medicine; Molecular Genetics and Microbiology; and Immunology; Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Michael B. Fessler
- Laboratory of Respiratory Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Gregory A. Taylor
- Geriatric Research, Education, and Clinical Center, VA Medical Center, Durham, North Carolina, United States of America
- Departments of Medicine; Molecular Genetics and Microbiology; and Immunology; Division of Geriatrics, and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
19
|
Tsukamoto T, Li X, Morita H, Minowa T, Aizawa T, Hanagata N, Demura M. Role of S-palmitoylation on IFITM5 for the interaction with FKBP11 in osteoblast cells. PLoS One 2013; 8:e75831. [PMID: 24058703 PMCID: PMC3776769 DOI: 10.1371/journal.pone.0075831] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/19/2013] [Indexed: 12/29/2022] Open
Abstract
Recently, one of the interferon-induced transmembrane (IFITM) family proteins, IFITM3, has become an important target for the activity against influenza A (H1N1) virus infection. In this protein, a post-translational modification by fatty acids covalently attached to cysteine, termed S-palmitoylation, plays a crucial role for the antiviral activity. IFITM3 possesses three cysteine residues for the S-palmitoylation in the first transmembrane (TM1) domain and in the cytoplasmic (CP) loop. Because these cysteines are well conserved in the mammalian IFITM family proteins, the S-palmitoylation on these cysteines is significant for their functions. IFITM5 is another IFITM family protein and interacts with the FK506-binding protein 11 (FKBP11) to form a higher-order complex in osteoblast cells, which induces the expression of immunologically relevant genes. In this study, we investigated the role played by S-palmitoylation of IFITM5 in its interaction with FKBP11 in the cells, because this interaction is a key process for the gene expression. Our investigations using an established reporter, 17-octadecynoic acid (17-ODYA), and an inhibitor for the S-palmitoylation, 2-bromopalmitic acid (2BP), revealed that IFITM5 was S-palmitoylated in addition to IFITM3. Specifically, we found that cysteine residues in the TM1 domain and in the CP loop were S-palmitoylated in IFITM5. Then, we revealed by immunoprecipitation and western blot analyses that the interaction of IFITM5 with FKBP11 was inhibited in the presence of 2BP. The mutant lacking the S-palmitoylation site in the TM1 domain lost the interaction with FKBP11. These results indicate that the S-palmitoylation on IFITM5 promotes the interaction with FKBP11. Finally, we investigated bone nodule formation in osteoblast cells in the presence of 2BP, because IFITM5 was originally identified as a bone formation factor. The experiment resulted in a morphological aberration of the bone nodule. This also indicated that the S-palmitoylation contributes to bone formation.
Collapse
Affiliation(s)
- Takashi Tsukamoto
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
- * E-mail: (TT); (MD)
| | - Xianglan Li
- Nanotechnology Innovation Station, National Institute for Materials Science, Tsukuba, Japan
| | - Hiromi Morita
- Nanotechnology Innovation Station, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Minowa
- Nanotechnology Innovation Station, National Institute for Materials Science, Tsukuba, Japan
| | - Tomoyasu Aizawa
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Nobutaka Hanagata
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Nanotechnology Innovation Station, National Institute for Materials Science, Tsukuba, Japan
| | - Makoto Demura
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
- * E-mail: (TT); (MD)
| |
Collapse
|
20
|
Liu R, Wang D, Shi Q, Fu Q, Hizon S, Xiang YK. Palmitoylation regulates intracellular trafficking of β2 adrenergic receptor/arrestin/phosphodiesterase 4D complexes in cardiomyocytes. PLoS One 2012; 7:e42658. [PMID: 22912718 PMCID: PMC3415400 DOI: 10.1371/journal.pone.0042658] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 07/10/2012] [Indexed: 01/19/2023] Open
Abstract
β2 adrenergic receptor (β2AR) is a prototypical G-protein coupled receptor that stimulates the classic cAMP-protein kinase A (PKA) signaling pathway. Recent studies indicate that the cAMP-PKA activities are spatiotemporally regulated in part due to dynamic association of β2AR with phosphodiesterase 4D (PDE4D), a group of cAMP degradation enzymes. Here, we demonstrate that in cardiomyocytes, palmitoylation of β2AR, the covalent acylation of cysteine residue 341, plays a critical role in shaping subcellular cAMP-PKA activities in cardiomyocytes via regulating β2AR association with arrestin/PDE4D. Replacing cysteine 341 on β2AR with alanine (C341A) leads to an impaired binding to β arrestin 2. Surprisingly, the C341A mutant is able to internalize via an arrestin-independent pathway at saturated concentration of agonist stimulation; the internalization becomes caveolae-dependent and requires dynamin GTPase. However, the impaired binding to β arrestin 2 also leads to an impaired recruitment of PDE4D to the C341A mutant. Thus, the mutant C341A β2AR is transported alone from the plasma membrane to the endosome without recruiting PDE4D. This alteration leads to an enhanced cytoplasmic cAMP signal for PKA activation under β2AR stimulation. Functionally, Mutation of the C341 residue or inhibition of palmitoylation modification of β2AR enhances the receptor-induced PKA activities in the cytoplasm and increases in myocyte contraction rate. Our data reveal a novel function of palmitoylation in shaping subcellular cAMP-PKA signaling in cardiomyocytes via modulating the recruitment of β arrestin 2-PDE4D complexes to the agonist-stimulated β2AR.
Collapse
Affiliation(s)
- Ruijie Liu
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Dayong Wang
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Qian Shi
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Qin Fu
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Steven Hizon
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
| | - Yang K. Xiang
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana Champaign, Urbana, Illinois, United States of America
- Department of Pharmacology, University of California Davis, Davis, California, United States of America
- * E-mail:
| |
Collapse
|
21
|
Kim SY, Lee JH, Huh JW, Ro JY, Oh YM, Lee SD, An S, Lee YS. Cigarette smoke induces Akt protein degradation by the ubiquitin-proteasome system. J Biol Chem 2011; 286:31932-43. [PMID: 21778238 PMCID: PMC3173210 DOI: 10.1074/jbc.m111.267633] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 07/13/2011] [Indexed: 11/06/2022] Open
Abstract
Emphysema is one of the characteristic features of chronic obstructive pulmonary disease, which is caused mainly by cigarette smoking. Recent data have suggested that apoptosis and cell cycle arrest may contribute to the development of emphysema. In this study, we addressed the question of whether and how cigarette smoke affected Akt, which plays a critical role in cell survival and proliferation. In normal human lung fibroblasts, cigarette smoke extract (CSE) caused cell death, accompanying degradation of total and phosphorylated Akt (p-Akt), which was inhibited by MG132. CSE exposure resulted in preferential ubiquitination of the active Akt (myristoylated), rather than the inactive (T308A/S473A double mutant) Akt. Consistent with cytotoxicity, CSE induced a progressive decrease of phosphorylated human homolog of mouse double minute homolog 2 (p-HDM2) and phosphorylated apoptosis signal regulating kinase 1 (p-ASK1) with concomitant elevation of p53, p21, and phosphorylated p38 MAPK. Forced expression of the active Akt reduced both CSE-induced cytotoxicity and alteration in HDM2/p53/p21 and ASK1/p38 MAPK, compared with the inactive Akt. Of note, CSE induced expression of the tetratrico-peptide repeat domain 3 (TTC3), known as a ubiquitin ligase for active Akt. TTC3 siRNAs suppressed not only CSE-induced Akt degradation but also CSE-induced cytotoxicity. Accordingly, rat lungs exposed to cigarette smoke for 3 months showed elevated TTC3 expression and reduced Akt and p-Akt. Taken together, these data suggest that cigarette smoke induces cytotoxicity, partly through Akt degradation via the ubiquitin-proteasome system, in which TTC3 acts as a ubiquitin ligase for active Akt.
Collapse
Affiliation(s)
- Sun-Yong Kim
- From the Division of Pharmacology, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Suwon 440-746
| | - Ji-Hyun Lee
- the Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, College of Medicine, Pochon CHA University, Seongnam 463-712
| | - Jin Won Huh
- the Department of Pulmonary and Critical Care Medicine, Asthma Center, and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, and
| | - Jai Youl Ro
- From the Division of Pharmacology, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Suwon 440-746
| | - Yeon-Mock Oh
- the Department of Pulmonary and Critical Care Medicine, Asthma Center, and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, and
| | - Sang-Do Lee
- the Department of Pulmonary and Critical Care Medicine, Asthma Center, and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, and
| | - Sungkwan An
- the Functional Genoproteome Research Centre, Konkuk University, Seoul 143-701, Republic of Korea
| | - Yun-Song Lee
- From the Division of Pharmacology, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Suwon 440-746
| |
Collapse
|
22
|
Van Dolah DK, Mao LM, Shaffer C, Guo ML, Fibuch EE, Chu XP, Buch S, Wang JQ. Reversible palmitoylation regulates surface stability of AMPA receptors in the nucleus accumbens in response to cocaine in vivo. Biol Psychiatry 2011; 69:1035-42. [PMID: 21216391 PMCID: PMC3089809 DOI: 10.1016/j.biopsych.2010.11.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 11/11/2010] [Accepted: 11/12/2010] [Indexed: 01/10/2023]
Abstract
BACKGROUND Palmitoylation is emerging as one of the most important posttranslational modifications of excitatory synaptic proteins in mammalian brain cells. As a reversible and regulatable modification sensitive to changing synaptic inputs, palmitoylation of ionotropic glutamate receptors contributes not only to the modulation of normal receptor and synaptic activities but also to the pathogenesis of various neuropsychiatric disorders. Here we report that palmitoylation of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor is regulated by the psychostimulant, cocaine, and such regulation is involved in cocaine action. METHODS We tested palmitoylation and surface expression of AMPA receptors in striatal neurons and psychomotor behavior in response to cocaine in rats. RESULTS All four AMPA receptor subunits (GluA1-4 or GluR1-4) are palmitoylated in the nucleus accumbens (NAc) of adult rats. Among them, GluA1 and GluA3 are preferentially upregulated in their palmitoylation levels by a systemic injection of cocaine. The upregulated GluA1 and 3 palmitoylation is a transient and reversible event. Consequently, it increases the susceptibility of surface-expressed GluA1 and 3 to internalization trafficking, leading to a temporal loss of surface receptor expression. Blockade of the regulated GluA1/3 palmitoylation with a palmitoylation inhibitor in the local NAc reverses the loss of surface GluA1/3. The inhibition of palmitoylation concurrently sustains behavioral responsivity to cocaine as well. CONCLUSIONS Our data identify a novel drug-palmitoylation coupling in the center of limbic reward circuits. Through palmitoylating selective AMPA receptor subunits, cocaine activity dependently regulates trafficking and subcellular localization of the receptor in NAc neurons and dynamically controls psychomotor sensitivity to the psychoactive drug in vivo.
Collapse
Affiliation(s)
- Dustin K. Van Dolah
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Li-Min Mao
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Christopher Shaffer
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Ming-Lei Guo
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Eugene E. Fibuch
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Xiang-Ping Chu
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - John Q. Wang
- Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
- Corresponding author: Dr. John Q. Wang, Department of Basic Medical Science, University of Missouri-Kansas City, School of Medicine, 2411 Holmes Street, Kansas City, Missouri 64108, USA, Tel: (816) 235-1786; Fax: (816) 235-5574,
| |
Collapse
|
23
|
Wei X, Schneider JG, Shenouda SM, Lee A, Towler DA, Chakravarthy MV, Vita JA, Semenkovich CF. De novo lipogenesis maintains vascular homeostasis through endothelial nitric-oxide synthase (eNOS) palmitoylation. J Biol Chem 2011; 286:2933-45. [PMID: 21098489 PMCID: PMC3024788 DOI: 10.1074/jbc.m110.193037] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Revised: 11/19/2010] [Indexed: 12/17/2022] Open
Abstract
Endothelial dysfunction leads to lethal vascular complications in diabetes and related metabolic disorders. Here, we demonstrate that de novo lipogenesis, an insulin-dependent process driven by the multifunctional enzyme fatty-acid synthase (FAS), maintains endothelial function by targeting endothelial nitric-oxide synthase (eNOS) to the plasma membrane. In mice with endothelial inactivation of FAS (FASTie mice), eNOS membrane content and activity were decreased. eNOS and FAS were physically associated; eNOS palmitoylation was decreased in FAS-deficient cells, and incorporation of labeled carbon into eNOS-associated palmitate was FAS-dependent. FASTie mice manifested a proinflammatory state reflected as increases in vascular permeability, endothelial inflammatory markers, leukocyte migration, and susceptibility to LPS-induced death that was reversed with an NO donor. FAS-deficient endothelial cells showed deficient migratory capacity, and angiogenesis was decreased in FASTie mice subjected to hindlimb ischemia. Insulin induced FAS in endothelial cells freshly isolated from humans, and eNOS palmitoylation was decreased in mice with insulin-deficient or insulin-resistant diabetes. Thus, disrupting eNOS bioavailability through impaired lipogenesis identifies a novel mechanism coordinating nutritional status and tissue repair that may contribute to diabetic vascular disease.
Collapse
Affiliation(s)
- Xiaochao Wei
- From the Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine
| | - Jochen G. Schneider
- From the Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine
| | - Sherene M. Shenouda
- the Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Ada Lee
- From the Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine
| | - Dwight A. Towler
- From the Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | - Manu V. Chakravarthy
- From the Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine
| | - Joseph A. Vita
- the Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Clay F. Semenkovich
- From the Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine
- Department of Cell Biology and Physiology, and
| |
Collapse
|
24
|
Augoff K, Kolondra A, Chorzalska A, Lach A, Grabowski K, Sikorski AF. Expression, purification and functional characterization of recombinant human acyl-CoA-binding protein (ACBP) from erythroid cells. Acta Biochim Pol 2010; 57:533-540. [PMID: 21079819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 10/06/2010] [Accepted: 11/13/2010] [Indexed: 05/30/2023]
Abstract
Fatty acyl-CoA esters are extremely important in cellular homeostasis. They are intermediates in both lipid metabolism and post-translational protein modifications. Among these modification events, protein palmitoylation seems to be unique by its reversibility which allows dynamic regulation of the protein hydrophobicity. The recent discovery of an enzyme family that catalyze protein palmitoylation has increased the understanding of the enzymology of the covalent attachment of fatty acids to proteins. Despite that, the molecular mechanism of supplying acyl-CoA esters to this reaction is yet to be established. Acyl-coenzyme A-binding proteins are known to bind long-chain acyl-CoA esters with very high affinity. Therefore, they play a significant role in intracellular acyl-CoA transport and pool formation. The purpose of this work is to explore the potential of one of the acyl-CoA-binding proteins to participate in the protein palmitoylation. In this study, a recombinant form of ACBP derived from human erythroid cells was expressed in E. coli, purified, and functionally characterized. We demonstrate that recombinant hACBP effectively binds palmitoyl-CoA in vitro, undergoing a shift from a monomeric to a dimeric state, and that this ligand-binding ability is involved in erythrocytic membrane phosphatidylcholine (PC) remodeling but not in protein acylation.
Collapse
Affiliation(s)
- Katarzyna Augoff
- Department of Gastrointestinal and General Surgery, Wroclaw Medical University, Poland.
| | | | | | | | | | | |
Collapse
|
25
|
Galluzzo P, Ascenzi P, Bulzomi P, Marino M. The nutritional flavanone naringenin triggers antiestrogenic effects by regulating estrogen receptor alpha-palmitoylation. Endocrinology 2008; 149:2567-75. [PMID: 18239068 DOI: 10.1210/en.2007-1173] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Naringenin (Nar) is a component of fruits and vegetables associated with healthful benefits, such as in osteoporosis, cancer, and cardiovascular diseases. These protective effects have been linked with Nar antiestrogenic as well as estrogenic activities. Previous studies indicate that Nar impaired estrogen receptor (ER) alpha signaling by interfering with ERalpha-mediated activation of ERK and phosphoinositide 3-kinase signaling pathways in the absence of effects at the transcriptional level. The present studies evaluated the hypothesis that these Nar antagonistic effects occur at the level of the plasma membrane. Our results indicate that Nar induces ERalpha depalmitoylation faster than 17beta-estradiol, which results in receptor rapid dissociation from caveolin-1. Furthermore, Nar impedes ERalpha to bind adaptor (modulator of nongenomic actions of the ER) and signaling (c-Src) proteins involved in the activation of the mitogenic signaling cascades (i.e. ERK and phosphoinositide 3-kinase). On the other hand, Nar induces the ER-dependent, but palmitoylation-independent, activation of p38 kinase, which in turn is responsible for Nar-mediated antiproliferative effects in cancer cells. Altogether, these data highlight new ER-dependent mechanisms on the root of antiproliferative and antiestrogenic effects of Nar. Moreover, the different modulation of ERalpha palmitoylation exerted by different ligands represents a pivotal mechanism that drives cancer cell to proliferation or apoptosis.
Collapse
Affiliation(s)
- Paola Galluzzo
- Department of Biology, University Roma Tre, Viale G. Marconi, 446, I-00146 Roma, Italy
| | | | | | | |
Collapse
|
26
|
Das S, Ise T, Nagata S, Maeda H, Bera TK, Pastan I. Palmitoylation of POTE family proteins for plasma membrane targeting. Biochem Biophys Res Commun 2007; 363:751-6. [PMID: 17904529 PMCID: PMC2170890 DOI: 10.1016/j.bbrc.2007.09.045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Accepted: 09/07/2007] [Indexed: 11/24/2022]
Abstract
The POTE gene family is composed of 13 paralogs and likely evolved by duplications and remodeling of the human genome. One common property of POTE proteins is their localization on the inner aspect of the plasma membrane. To determine the structural elements required for membrane localization, we expressed mutants of different POTEs in 293T cells as EGFP fusion proteins. We also tested their palmitoylation by a biotin-switch assay. Our data indicate that the membrane localizations of different POTEs are mediated by similar 3-4 short cysteine rich repeats (CRRs) near the amino-terminuses and that palmitoylation on paired cysteine residues in each CRR motif is responsible for the localization. Multiple palmitoylation in the small CRRs can result in the strong association of whole POTEs with plasma membrane.
Collapse
Affiliation(s)
| | | | | | | | | | - Ira Pastan
- *Corresponding author: Laboratory of Molecular Biology, National Cancer Institute, 37, Convent Drive, Room 5106, Bethesda, MD 20892-4264, USA, Tel: 301-496-4797; Fax: 301-402-1344; e-mail:
| |
Collapse
|