1
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Cai J, Cui J, Wang L. S-palmitoylation regulates innate immune signaling pathways: molecular mechanisms and targeted therapies. Eur J Immunol 2023; 53:e2350476. [PMID: 37369620 DOI: 10.1002/eji.202350476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/10/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023]
Abstract
S-palmitoylation is a reversible posttranslational lipid modification that targets cysteine residues of proteins and plays critical roles in regulating the biological processes of substrate proteins. The innate immune system serves as the first line of defense against pathogenic invaders and participates in the maintenance of tissue homeostasis. Emerging studies have uncovered the functions of S-palmitoylation in modulating innate immune responses. In this review, we focus on the reversible palmitoylation of innate immune signaling proteins, with particular emphasis on its roles in the regulation of protein localization, protein stability, and protein-protein interactions. We also highlight the potential and challenge of developing therapies that target S-palmitoylation or de-palmitoylation for various diseases.
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Affiliation(s)
- Jing Cai
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jun Cui
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Liqiu Wang
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences of Sun Yat-sen University, Guangzhou, Guangdong, China
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2
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Li M, Zhang L, Chen CW. Diverse Roles of Protein Palmitoylation in Cancer Progression, Immunity, Stemness, and Beyond. Cells 2023; 12:2209. [PMID: 37759431 PMCID: PMC10526800 DOI: 10.3390/cells12182209] [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: 07/20/2023] [Revised: 08/27/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Protein S-palmitoylation, a type of post-translational modification, refers to the reversible process of attachment of a fatty acyl chain-a 16-carbon palmitate acid-to the specific cysteine residues on target proteins. By adding the lipid chain to proteins, it increases the hydrophobicity of proteins and modulates protein stability, interaction with effector proteins, subcellular localization, and membrane trafficking. Palmitoylation is catalyzed by a group of zinc finger DHHC-containing proteins (ZDHHCs), whereas depalmitoylation is catalyzed by a family of acyl-protein thioesterases. Increasing numbers of oncoproteins and tumor suppressors have been identified to be palmitoylated, and palmitoylation is essential for their functions. Understanding how palmitoylation influences the function of individual proteins, the physiological roles of palmitoylation, and how dysregulated palmitoylation leads to pathological consequences are important drivers of current research in this research field. Further, due to the critical roles in modifying functions of oncoproteins and tumor suppressors, targeting palmitoylation has been used as a candidate therapeutic strategy for cancer treatment. Here, based on recent literatures, we discuss the progress of investigating roles of palmitoylation in regulating cancer progression, immune responses against cancer, and cancer stem cell properties.
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Affiliation(s)
- Mingli Li
- Department of Systems Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA;
| | - Leisi Zhang
- Department of Systems Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA;
| | - Chun-Wei Chen
- Department of Systems Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA;
- City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
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3
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He Q, Qu M, Shen T, Su J, Xu Y, Xu C, Barkat MQ, Cai J, Zhu H, Zeng LH, Wu X. Control of mitochondria-associated endoplasmic reticulum membranes by protein S-palmitoylation: Novel therapeutic targets for neurodegenerative diseases. Ageing Res Rev 2023; 87:101920. [PMID: 37004843 DOI: 10.1016/j.arr.2023.101920] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/30/2023] [Accepted: 03/30/2023] [Indexed: 04/03/2023]
Abstract
Mitochondria-associated endoplasmic reticulum membranes (MAMs) are dynamic coupling structures between mitochondria and the endoplasmic reticulum (ER). As a new subcellular structure, MAMs combine the two critical organelle functions. Mitochondria and the ER could regulate each other via MAMs. MAMs are involved in calcium (Ca2+) homeostasis, autophagy, ER stress, lipid metabolism, etc. Researchers have found that MAMs are closely related to metabolic syndrome and neurodegenerative diseases (NDs). The formation of MAMs and their functions depend on specific proteins. Numerous protein enrichments, such as the IP3R-Grp75-VDAC complex, constitute MAMs. The changes in these proteins govern the interaction between mitochondria and the ER; they also affect the biological functions of MAMs. S-palmitoylation is a reversible protein post-translational modification (PTM) that mainly occurs on protein cysteine residues. More and more studies have shown that the S-palmitoylation of proteins is closely related to their membrane localization. Here, we first briefly describe the composition and function of MAMs, reviewing the component and biological roles of MAMs mediated by S-palmitoylation, elaborating on S-palmitoylated proteins in Ca2+ flux, lipid rafts, and so on. We try to provide new insight into the molecular basis of MAMs-related diseases, mainly NDs. Finally, we propose potential drug compounds targeting S-palmitoylation.
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Affiliation(s)
- Qiangqiang He
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China; Department of Pharmacology, Hangzhou City University, Hangzhou 310015, China
| | - Meiyu Qu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Tingyu Shen
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jiakun Su
- Technology Center, China Tobacco Jiangxi Industrial Co. Ltd., Nanchang 330096, China
| | - Yana Xu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Chengyun Xu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Muhammad Qasim Barkat
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jibao Cai
- Technology Center, China Tobacco Jiangxi Industrial Co. Ltd., Nanchang 330096, China
| | - Haibin Zhu
- Department of Gynecology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Ling-Hui Zeng
- Department of Pharmacology, Hangzhou City University, Hangzhou 310015, China.
| | - Ximei Wu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China.
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4
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Lan T, Delalande C, Dickinson BC. Inhibitors of DHHC family proteins. Curr Opin Chem Biol 2021; 65:118-125. [PMID: 34467875 DOI: 10.1016/j.cbpa.2021.07.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/14/2021] [Accepted: 07/19/2021] [Indexed: 02/08/2023]
Abstract
Protein S-acylation is a prevalent post-translational protein lipidation that is dynamically regulated by 'writer' protein S-acyltransferases and 'eraser' acylprotein thioesterases. The protein S-acyltransferases comprise 23 aspartate-histidine-histidine-cysteine (DHHC)-containing proteins, which transfer fatty acid acyl groups from acyl-coenzyme A onto protein substrates. DHHC proteins are increasingly recognized as critical regulators of S-acylation-mediated cellular processes and pathology. As our understanding of the importance and breadth of DHHC-mediated biology and pathology expands, so too does the need for chemical inhibitors of this class of proteins. In this review, we discuss the challenges and progress in DHHC inhibitor development, focusing on 2-bromopalmitate, the most commonly used inhibitor in the field, and N-cyanomethyl-N-myracrylamide, a new broad-spectrum DHHC inhibitor. We believe that current and ongoing advances in structure elucidation, mechanistic interrogation, and novel inhibitor design around DHHC proteins will spark innovative strategies to modulate these critical proteins in living systems.
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Affiliation(s)
- Tong Lan
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, United States
| | - Clémence Delalande
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, United States
| | - Bryan C Dickinson
- Department of Chemistry, The University of Chicago, Chicago, IL 60637, United States.
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5
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Chong LW, Tsai CL, Yang KC, Liao CC, Hsu YC. Targeting protein palmitoylation decreases palmitate‑induced sphere formation of human liver cancer cells. Mol Med Rep 2020; 22:939-947. [PMID: 32468006 PMCID: PMC7339714 DOI: 10.3892/mmr.2020.11172] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/15/2020] [Indexed: 01/22/2023] Open
Abstract
Although non-alcoholic fatty liver disease (NAFLD) is considered a benign disorder, hepatic steatosis has been proposed to be involved in the tumorigenesis of liver cancer. However, the underlying mechanism for carcinogenesis in fatty liver diseases remains unclear. Cancer stem cells (CSCs) have been hypothesized to serve a key role in tumorigenesis. Tumor formation begins with a subset of heterogeneous cells that share properties with stem cells, such as self-renewal and undifferentiated properties. Our previous study reported that the saturated fatty acid palmitate (PA) significantly enhanced the CSC properties of the HepG2 human liver cancer cell line; however, its underlying mechanisms are unknown. In the present study, a proteomic approach was used to investigate the palmitoylation of proteins in HepG2 CSCs. CSC behavior was induced in HepG2 cells via 200 µM PA. Proteomic analysis was performed to identify post-transcriptional modifications of proteins in HepG2 CSCs in response to PA treatment. The present study identified proteins modified by palmitoylation in HepG2 CSC spheres formed following PA treatment. It was therefore hypothesized that palmitoylation may be crucial for CSC sphere formation. Furthermore, the present study demonstrated that two palmitoylation inhibitors, tunicamycin (5, 10 and 25 µg/ml) and 2-bromohexadecanoic acid (25, 50 and 150 µM), significantly decreased CSC sphere formation without affecting cell viability. An association was identified between sphere formation capacity and tumor-initiating capacity of CSCs. The results of the present study demonstrated that protein palmitoylation may influence the PA-induced CSC tumor-initiating capacity, and that the inhibition of palmitoylation may be a suitable chemopreventive strategy for treating patients with NAFLD.
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Affiliation(s)
- Lee-Won Chong
- Division of Hepatology and Gastroenterology, Department of Internal Medicine, Shin Kong Wu Ho Su Memorial Hospital, Taipei, Taiwan, R.O.C
| | - Chia-Ling Tsai
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taipei, Taiwan, R.O.C
| | - Kou-Ching Yang
- Division of Hepatology and Gastroenterology, Department of Internal Medicine, Shin Kong Wu Ho Su Memorial Hospital, Taipei, Taiwan, R.O.C
| | - Chen-Chung Liao
- Proteomics Research Center, National Yang‑Ming University, Taipei, Taiwan, R.O.C
| | - Yi-Chao Hsu
- Institute of Biomedical Sciences, Mackay Medical College, New Taipei City, Taipei, Taiwan, R.O.C
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6
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Park S, Jang A, Bouret SG. Maternal obesity-induced endoplasmic reticulum stress causes metabolic alterations and abnormal hypothalamic development in the offspring. PLoS Biol 2020; 18:e3000296. [PMID: 32163401 PMCID: PMC7067374 DOI: 10.1371/journal.pbio.3000296] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 02/05/2020] [Indexed: 01/19/2023] Open
Abstract
The steady increase in the prevalence of obesity and associated type II diabetes mellitus is a major health concern, particularly among children. Maternal obesity represents a risk factor that contributes to metabolic perturbations in the offspring. Endoplasmic reticulum (ER) stress has emerged as a critical mechanism involved in leptin resistance and type 2 diabetes in adult individuals. Here, we used a mouse model of maternal obesity to investigate the importance of early life ER stress in the nutritional programming of this metabolic disease. Offspring of obese dams developed glucose intolerance and displayed increased body weight, adiposity, and food intake. Moreover, maternal obesity disrupted the development of melanocortin circuits associated with neonatal hyperleptinemia and leptin resistance. ER stress-related genes were up-regulated in the hypothalamus of neonates born to obese mothers. Neonatal treatment with the ER stress-relieving drug tauroursodeoxycholic acid improved metabolic and neurodevelopmental deficits and reversed leptin resistance in the offspring of obese dams.
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Affiliation(s)
- Soyoung Park
- The Saban Research Institute, Developmental Neuroscience Program, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Alice Jang
- The Saban Research Institute, Developmental Neuroscience Program, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Sebastien G. Bouret
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, Lille, France
- University of Lille, FHU 1,000 Days for Health, Lille, France
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7
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Koster KP, Francesconi W, Berton F, Alahmadi S, Srinivas R, Yoshii A. Developmental NMDA receptor dysregulation in the infantile neuronal ceroid lipofuscinosis mouse model. eLife 2019; 8:40316. [PMID: 30946007 PMCID: PMC6464704 DOI: 10.7554/elife.40316] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 03/31/2019] [Indexed: 12/20/2022] Open
Abstract
Protein palmitoylation and depalmitoylation alter protein function. This post-translational modification is critical for synaptic transmission and plasticity. Mutation of the depalmitoylating enzyme palmitoyl-protein thioesterase 1 (PPT1) causes infantile neuronal ceroid lipofuscinosis (CLN1), a pediatric neurodegenerative disease. However, the role of protein depalmitoylation in synaptic maturation is unknown. Therefore, we studied synapse development in Ppt1-/- mouse visual cortex. We demonstrate that the developmental N-methyl-D-aspartate receptor (NMDAR) subunit switch from GluN2B to GluN2A is stagnated in Ppt1-/- mice. Correspondingly, Ppt1-/- neurons exhibit immature evoked NMDAR currents and dendritic spine morphology in vivo. Further, dissociated Ppt1-/- cultured neurons show extrasynaptic, diffuse calcium influxes and enhanced vulnerability to NMDA-induced excitotoxicity, reflecting the predominance of GluN2B-containing receptors. Remarkably, Ppt1-/- neurons demonstrate hyperpalmitoylation of GluN2B as well as Fyn kinase, which regulates surface retention of GluN2B. Thus, PPT1 plays a critical role in postsynapse maturation by facilitating the GluN2 subunit switch and proteostasis of palmitoylated proteins.
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Affiliation(s)
- Kevin P Koster
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, United States
| | - Walter Francesconi
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, United States
| | - Fulvia Berton
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, United States
| | - Sami Alahmadi
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, United States
| | - Roshan Srinivas
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, United States
| | - Akira Yoshii
- Department of Pediatrics, University of Illinois at Chicago, Chicago, United States.,Department of Neurology, University of Illinois at Chicago, Chicago, United States
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8
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Martínez-Burgo Y, Santos-Aberturas J, Rodríguez-García A, Barreales EG, Tormo JR, Truman AW, Reyes F, Aparicio JF, Liras P. Activation of Secondary Metabolite Gene Clusters in Streptomyces clavuligerus by the PimM Regulator of Streptomyces natalensis. Front Microbiol 2019; 10:580. [PMID: 30984130 PMCID: PMC6448028 DOI: 10.3389/fmicb.2019.00580] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/06/2019] [Indexed: 11/13/2022] Open
Abstract
Expression of non-native transcriptional activators may be a powerful general method to activate secondary metabolites biosynthetic pathways. PAS-LuxR regulators, whose archetype is PimM, activate the biosynthesis of polyene macrolide antifungals and other antibiotics, and have been shown to be functionally preserved across multiple Streptomyces strains. In this work we show that constitutive expression of pimM in Streptomyces clavuligerus ATCC 27064 significantly affected its transcriptome and modifies secondary metabolism. Almost all genes in three secondary metabolite clusters were overexpressed, including the clusters responsible for the biosynthesis of the clinically important clavulanic acid and cephamycin C. In comparison to a control strain, this resulted in 10- and 7-fold higher production levels of these metabolites, respectively. Metabolomic and bioactivity studies of S. clavuligerus::pimM also revealed deep metabolic changes. Antifungal activity absent in the control strain was detected in S. clavuligerus::pimM, and determined to be the result of a fivefold increase in the production of the tunicamycin complex.
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Affiliation(s)
| | | | - Antonio Rodríguez-García
- Microbiology Section, Department of Molecular Biology, University of León, León, Spain.,Institute of Biotechnology of León, INBIOTEC, León, Spain
| | - Eva G Barreales
- Microbiology Section, Department of Molecular Biology, University of León, León, Spain
| | - José Rubén Tormo
- Centre of Excellence for Research into Innovative Medicine, Health Sciences Technology, MEDINA, Granada, Spain
| | - Andrew W Truman
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
| | - Fernando Reyes
- Centre of Excellence for Research into Innovative Medicine, Health Sciences Technology, MEDINA, Granada, Spain
| | - Jesús F Aparicio
- Microbiology Section, Department of Molecular Biology, University of León, León, Spain
| | - Paloma Liras
- Microbiology Section, Department of Molecular Biology, University of León, León, Spain
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9
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Lu H, Cherepanova NA, Gilmore R, Contessa JN, Lehrman MA. Targeting STT3A-oligosaccharyltransferase with NGI-1 causes herpes simplex virus 1 dysfunction. FASEB J 2019; 33:6801-6812. [PMID: 30811219 DOI: 10.1096/fj.201802044rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Herpes simplex virus 1 (HSV-1) is a contagious neurotropic herpesvirus responsible for oral lesions and herpesviral encephalitis. The HSV-1 envelope contains N-glycosylated proteins involved in infection and that are candidate drug targets. NGI-1 is a small-molecule inhibitor of oligosaccharyltransferase (OST) complexes STT3A-OST and STT3B-OST, which catalyze cotranslational and post-translational N-glycosylation, respectively. Because host OSTs attach HSV-1 glycans, NGI-1 might have anti-HSV-1 activity. We evaluated HSV-1 function using NGI-1 and human embryonic kidney 293 knockout lines for OST isoform-specific catalytic and accessory subunits. N-glycosylation of 2 representative envelope proteins (gC and gD) was primarily dependent upon STT3A-OST, but to a large extent replaceable by STT3B-OST. Knockouts impairing STT3A- or STT3B-OST activity, by themselves, did not appreciably affect HSV-1 function (plaque-forming units, normalized to viral particles measured by unglycosylated capsid protein VP5 content). However, with cells lacking STT3B-OST activity (missing the catalytic subunit STT3B or the oxidoreductase subunits magnesium transporter 1/tumor suppressor candidate 3) and thus solely dependent upon STT3A-OST for N-glycosylation, NGI-1 treatment resulted in HSV-1 having cell type-dependent dysfunction (affecting infectivity with Vero cells much more than with the 293 lines). Ablation of post-translational N-glycosylation can therefore make HSV-1 infectivity, and possibly masking of immunogenic peptide epitopes by glycans, highly sensitive to pharmacological inhibition of cotranslational N-glycosylation.-Lu, H., Cherepanova, N. A., Gilmore, R., Contessa, J. N., Lehrman, M. A. Targeting STT3A-oligosaccharyltransferase with NGI-1 causes herpes simplex virus 1 dysfunction.
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Affiliation(s)
- Hua Lu
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Natalia A Cherepanova
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Reid Gilmore
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Joseph N Contessa
- Department of Therapeutic Radiology and Pharmacology, Yale School of Medicine, New Haven, Connecticut, USA.,Department of Pharmacology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Mark A Lehrman
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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10
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Zaballa ME, van der Goot FG. The molecular era of protein S-acylation: spotlight on structure, mechanisms, and dynamics. Crit Rev Biochem Mol Biol 2018; 53:420-451. [DOI: 10.1080/10409238.2018.1488804] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- María-Eugenia Zaballa
- Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - F. Gisou van der Goot
- Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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11
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Holland SM, Thomas GM. Roles of palmitoylation in axon growth, degeneration and regeneration. J Neurosci Res 2017; 95:1528-1539. [PMID: 28150429 DOI: 10.1002/jnr.24003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 11/09/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
The protein-lipid modification palmitoylation plays important roles in neurons, but most attention has focused on roles of this modification in the regulation of mature pre- and post-synapses. However, exciting recent findings suggest that palmitoylation is also critical for both the growth and integrity of neuronal axons and plays previously unappreciated roles in conveying axonal anterograde and retrograde signals. Here we review these emerging roles for palmitoylation in the regulation of axons in health and disease. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Sabrina M Holland
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair)
| | - Gareth M Thomas
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair).,Department of Anatomy and Cell Biology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140
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12
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Dickey DM, Edmund AB, Otto NM, Chaffee TS, Robinson JW, Potter LR. Catalytically Active Guanylyl Cyclase B Requires Endoplasmic Reticulum-mediated Glycosylation, and Mutations That Inhibit This Process Cause Dwarfism. J Biol Chem 2016; 291:11385-93. [PMID: 26980729 DOI: 10.1074/jbc.m115.704015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Indexed: 01/18/2023] Open
Abstract
C-type natriuretic peptide activation of guanylyl cyclase B (GC-B), also known as natriuretic peptide receptor B or NPR2, stimulates long bone growth, and missense mutations in GC-B cause dwarfism. Four such mutants (L658F, Y708C, R776W, and G959A) bound (125)I-C-type natriuretic peptide on the surface of cells but failed to synthesize cGMP in membrane GC assays. Immunofluorescence microscopy also indicated that the mutant receptors were on the cell surface. All mutant proteins were dephosphorylated and incompletely glycosylated, but dephosphorylation did not explain the inactivation because the mutations inactivated a "constitutively phosphorylated" enzyme. Tunicamycin inhibition of glycosylation in the endoplasmic reticulum or mutation of the Asn-24 glycosylation site decreased GC activity, but neither inhibition of glycosylation in the Golgi by N-acetylglucosaminyltransferase I gene inactivation nor PNGase F deglycosylation of fully processed GC-B reduced GC activity. We conclude that endoplasmic reticulum-mediated glycosylation is required for the formation of an active catalytic, but not ligand-binding domain, and that mutations that inhibit this process cause dwarfism.
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Affiliation(s)
- Deborah M Dickey
- From the Departments of Biochemistry, Molecular Biology, and Biophysics and
| | - Aaron B Edmund
- From the Departments of Biochemistry, Molecular Biology, and Biophysics and
| | - Neil M Otto
- From the Departments of Biochemistry, Molecular Biology, and Biophysics and
| | - Thomas S Chaffee
- From the Departments of Biochemistry, Molecular Biology, and Biophysics and
| | - Jerid W Robinson
- From the Departments of Biochemistry, Molecular Biology, and Biophysics and
| | - Lincoln R Potter
- From the Departments of Biochemistry, Molecular Biology, and Biophysics and Pharmacology, University of Minnesota, Minneapolis, Minnesota 55455
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13
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Protein S-palmitoylation and cancer. Biochim Biophys Acta Rev Cancer 2015; 1856:107-20. [PMID: 26112306 DOI: 10.1016/j.bbcan.2015.06.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/16/2015] [Accepted: 06/21/2015] [Indexed: 12/16/2022]
Abstract
Protein S-palmitoylation is a reversible posttranslational modification of proteins with fatty acids, an enzymatic process driven by a recently discovered family of protein acyltransferases (PATs) that are defined by a conserved catalytic domain characterized by a DHHC sequence motif. Protein S-palmitoylation has a prominent role in regulating protein location, trafficking and function. Recent studies of DHHC PATs and their functional effects have demonstrated that their dysregulation is associated with human diseases, including schizophrenia, X-linked mental retardation, and Huntington's Disease. A growing number of reports indicate an important role for DHHC proteins and their substrates in tumorigenesis. Whereas DHHC PATs comprise a family of 23 enzymes in humans, a smaller number of enzymes that remove palmitate have been identified and characterized as potential therapeutic targets. Here we review current knowledge of the enzymes that mediate reversible palmitoylation and their cancer-associated substrates and discuss potential therapeutic applications.
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14
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Ma G, Liu Y. The reaction mechanism of UDP-GlcNAc 5,6-dehydratase: a quantum mechanical/molecular mechanical (QM/MM) study. Theor Chem Acc 2014. [DOI: 10.1007/s00214-014-1524-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Savastano LE, Laurito SR, Fitt MR, Rasmussen JA, Gonzalez Polo V, Patterson SI. Sciatic nerve injury: A simple and subtle model for investigating many aspects of nervous system damage and recovery. J Neurosci Methods 2014; 227:166-80. [DOI: 10.1016/j.jneumeth.2014.01.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 01/16/2014] [Accepted: 01/20/2014] [Indexed: 02/04/2023]
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16
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Blaskovic S, Adibekian A, Blanc M, van der Goot GF. Mechanistic effects of protein palmitoylation and the cellular consequences thereof. Chem Phys Lipids 2014; 180:44-52. [PMID: 24534427 DOI: 10.1016/j.chemphyslip.2014.02.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/31/2014] [Accepted: 02/03/2014] [Indexed: 12/21/2022]
Abstract
S-palmitoylation involves the attachment of a 16-carbon long fatty acid chain to the cysteine residues of proteins. The process is enzymatic and dynamic with DHHC enzymes mediating palmitoylation and acyl-protein thioesterases reverting the reaction. Proteins that undergo this modification span almost all cellular functions. While the increase in hydrophobicity generated by palmitoylation has the obvious consequence of triggering membrane association, the effects on transmembrane proteins are less intuitive and span a vast range. We review here the current knowledge on palmitoylating and depalmitoylating enzymes, the methods that allow the study of this lipid modification and which drugs can affect it, and finally we focus on four cellular processes for which recent studies reveal an involvement of palmitoylation: endocytosis, reproduction and cell growth, fat and sugar homeostasis and signal transduction at the synapse.
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Affiliation(s)
- Sanja Blaskovic
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Alexander Adibekian
- Department of Organic Chemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Mathieu Blanc
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Gisou F van der Goot
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland.
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17
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McCully BH, Hasan W, Streiff CT, Houle JC, Woodward WR, Giraud GD, Brooks VL, Habecker BA. Sympathetic cardiac hyperinnervation and atrial autonomic imbalance in diet-induced obesity promote cardiac arrhythmias. Am J Physiol Heart Circ Physiol 2013; 305:H1530-7. [PMID: 24014675 DOI: 10.1152/ajpheart.00196.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Obesity increases the risk of arrhythmias and sudden cardiac death, but the mechanisms are unknown. This study tested the hypothesis that obesity-induced cardiac sympathetic outgrowth and hyperinnervation promotes the development of arrhythmic events. Male Sprague-Dawley rats (250-275 g), fed a high-fat diet (33% kcal/fat), diverged into obesity-resistant (OR) and obesity-prone (OP) groups and were compared with rats fed normal chow (13% kcal/fat; CON). In vitro experiments showed that both OR and OP rats exhibited hyperinnervation of the heart and high sympathetic outgrowth compared with CON rats, even though OR rats are not obese. Despite the hyperinnervation and outgrowth, we showed that, in vivo, OR rats were less susceptible to arrhythmic events after an intravenous epinephrine challenge compared with OP rats. On examining total and stimulus-evoked neurotransmitter levels in an ex vivo system, we demonstrate that atrial acetylcholine content and release were attenuated in OP compared with OR and CON groups. OP rats also expressed elevated atrial norepinephrine content, while norepinephrine release was suppressed. These findings suggest that the consumption of a high-fat diet, even in the absence of overt obesity, stimulates sympathetic outgrowth and hyperinnervation of the heart. However, normalized cardiac parasympathetic nervous system control may protect the heart from arrhythmic events.
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Affiliation(s)
- Belinda H McCully
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon; and
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18
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Lin CI, McCarty RM, Liu HW. The biosynthesis of nitrogen-, sulfur-, and high-carbon chain-containing sugars. Chem Soc Rev 2013; 42:4377-407. [PMID: 23348524 PMCID: PMC3641179 DOI: 10.1039/c2cs35438a] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Carbohydrates serve many structural and functional roles in biology. While the majority of monosaccharides are characterized by the chemical composition (CH2O)n, modifications including deoxygenation, C-alkylation, amination, O- and N-methylation, which are characteristic of many sugar appendages of secondary metabolites, are not uncommon. Interestingly, some sugar molecules are formed via modifications including amine oxidation, sulfur incorporation, and "high-carbon" chain attachment. Most of these unusual sugars have been identified over the past several decades as components of microbially produced natural products, although a few high-carbon sugars are also found in the lipooligosaccharides of the outer cell walls of Gram-negative bacteria. Despite their broad distribution in nature, these sugars are considered "rare" due to their relative scarcity. The biosynthetic steps that underlie their formation continue to perplex researchers to this day and many questions regarding key transformations remain unanswered. This review will focus on our current understanding of the biosynthesis of unusual sugars bearing oxidized amine substituents, thio-functional groups, and high-carbon chains.
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Affiliation(s)
| | | | - Hung-wen Liu
- Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712
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19
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Abstract
Protein palmitoylation describes the post-translational fatty acyl thioesterification of cellular cysteine residues and is critical for the localization, trafficking, and compartmentalization of a large number of membrane proteins. This labile thioester modification facilitates a dynamic acylation cycle that directionally traffics key signaling complexes, receptors, and channels to select membrane compartments. Chemical enrichment and advanced mass spectrometry-based proteomics methods have highlighted a pervasive role for palmitoylation across all eukaryotes, including animals, plants, and parasites. Emerging chemical tools promise to open new avenues to study the enzymes, substrates, and dynamics of this distinct post-translational modification.
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Affiliation(s)
- Christopher T.M.B. Tom
- Program in Chemical Biology and Department
of Chemistry, University of Michigan, 930
N. University Avenue, Ann
Arbor, Michigan 48109, United States
| | - Brent R. Martin
- Program in Chemical Biology and Department
of Chemistry, University of Michigan, 930
N. University Avenue, Ann
Arbor, Michigan 48109, United States
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20
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Affiliation(s)
- Howard C. Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, 1230 York Avenue, New York, NY 10065 (USA)
| | - Maurine E. Linder
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (USA)
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21
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Chen W, Qu D, Zhai L, Tao M, Wang Y, Lin S, Price NPJ, Deng Z. Characterization of the tunicamycin gene cluster unveiling unique steps involved in its biosynthesis. Protein Cell 2010; 1:1093-105. [PMID: 21153459 DOI: 10.1007/s13238-010-0127-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 10/26/2010] [Indexed: 01/03/2023] Open
Abstract
Tunicamycin, a potent reversible translocase I inhibitor, is produced by several Actinomycetes species. The tunicamycin structure is highly unusual, and contains an 11-carbon dialdose sugar and an α, β-1″,11'-glycosidic linkage. Here we report the identification of a gene cluster essential for tunicamycin biosynthesis by high-throughput heterologous expression (HHE) strategy combined with a bioassay. Introduction of the genes into heterologous non-producing Streptomyces hosts results in production of tunicamycin by these strains, demonstrating the role of the genes for the biosynthesis of tunicamycins. Gene disruption experiments coupled with bioinformatic analysis revealed that the tunicamycin gene cluster is minimally composed of 12 genes (tunA-tunL). Amongst these is a putative radical SAM enzyme (Tun B) with a potentially unique role in biosynthetic carbon-carbon bond formation. Hence, a seven-step novel pathway is proposed for tunicamycin biosynthesis. Moreover, two gene clusters for the potential biosynthesis of tunicamycin-like antibiotics were also identified in Streptomyces clavuligerus ATCC 27064 and Actinosynnema mirums DSM 43827. These data provide clarification of the novel mechanisms for tunicamycin biosynthesis, and for the generation of new-designer tunicamycin analogs with selective/enhanced bioactivity via combinatorial biosynthesis strategies.
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Affiliation(s)
- Wenqing Chen
- Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200030, China
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22
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Winn M, Goss RJM, Kimura KI, Bugg TDH. Antimicrobial nucleoside antibiotics targeting cell wall assembly: recent advances in structure-function studies and nucleoside biosynthesis. Nat Prod Rep 2009; 27:279-304. [PMID: 20111805 DOI: 10.1039/b816215h] [Citation(s) in RCA: 221] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The quest for new antibiotics, especially those with activity against Gram-negative bacteria, is urgent; however, very few new antibiotics have been marketed in the last 40 years, with this limited number falling into only four new structural classes. Several nucleoside natural product antibiotics target bacterial translocase MraY, involved in the lipid-linked cycle of peptidoglycan biosynthesis, and fungal chitin synthase. Biosynthetic studies on the nikkomycin, caprazamycin and pacidamycin/mureidomycin families are also reviewed.
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Affiliation(s)
- Michael Winn
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
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23
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Sämann J, Hegermann J, von Gromoff E, Eimer S, Baumeister R, Schmidt E. Caenorhabditits elegans LRK-1 and PINK-1 act antagonistically in stress response and neurite outgrowth. J Biol Chem 2009; 284:16482-16491. [PMID: 19251702 DOI: 10.1074/jbc.m808255200] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in two genes encoding the putative kinases LRRK2 and PINK1 have been associated with inherited variants of Parkinson disease. The physiological role of both proteins is not known at present, but studies in model organisms have linked their mutants to distinct aspects of mitochondrial dysfunction, increased vulnerability to oxidative and endoplasmic reticulum stress, and intracellular protein sorting. Here, we show that a mutation in the Caenorhabditits elegans homologue of the PTEN-induced kinase pink-1 gene resulted in reduced mitochondrial cristae length and increased paraquat sensitivity of the nematode. Moreover, the mutants also displayed defects in axonal outgrowth of a pair of canal-associated neurons. We demonstrate that in the absence of lrk-1, the C. elegans homologue of human LRRK2, all phenotypic aspects of pink-1 loss-of-function mutants were suppressed. Conversely, the hypersensitivity of lrk-1 mutant animals to the endoplasmic reticulum stressor tunicamycin was reduced in a pink-1 mutant background. These results provide the first evidence of an antagonistic role of PINK-1 and LRK-1. Due to the similarity of the C. elegans proteins to human LRRK2 and PINK1, we suggest a common role of both factors in cellular functions including stress response and regulation of neurite outgrowth. This study might help to link pink-1/PINK1 and lrk-1/LRRK2 function to the pathological processes resulting from Parkinson disease-related mutants in both genes, the first manifestations of which are cytoskeletal defects in affected neurons.
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Affiliation(s)
- Julia Sämann
- From Bioinformatics and Molecular Genetics (Faculty of Biology), ZBMZ (Faculty of Medicine), and ZBSA-Center for Systems Biology, Albert-Ludwigs-Universitaet Freiburg, 79104
| | - Jan Hegermann
- Freiburg and the European Neuroscience Institute (ENI) and Deutsche Forsch ungs ge mein schaft (DFG) Research Center for Molecular Physiology of the Brain (CMPB), University Medical Faculty, 37077 Göttingen, Germany
| | - Erika von Gromoff
- From Bioinformatics and Molecular Genetics (Faculty of Biology), ZBMZ (Faculty of Medicine), and ZBSA-Center for Systems Biology, Albert-Ludwigs-Universitaet Freiburg, 79104
| | - Stefan Eimer
- Freiburg and the European Neuroscience Institute (ENI) and Deutsche Forsch ungs ge mein schaft (DFG) Research Center for Molecular Physiology of the Brain (CMPB), University Medical Faculty, 37077 Göttingen, Germany
| | - Ralf Baumeister
- From Bioinformatics and Molecular Genetics (Faculty of Biology), ZBMZ (Faculty of Medicine), and ZBSA-Center for Systems Biology, Albert-Ludwigs-Universitaet Freiburg, 79104; Freiburg Institute for Advanced Studies, School of Life Sciences (LIFENET), and Centre for Biological Signalling Studies (BIOSS), 79104.
| | - Enrico Schmidt
- From Bioinformatics and Molecular Genetics (Faculty of Biology), ZBMZ (Faculty of Medicine), and ZBSA-Center for Systems Biology, Albert-Ludwigs-Universitaet Freiburg, 79104
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24
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Fox AP, Cahill AL, Currie KPM, Grabner C, Harkins AB, Herring B, Hurley JH, Xie Z. N- and P/Q-type Ca2+ channels in adrenal chromaffin cells. Acta Physiol (Oxf) 2008; 192:247-61. [PMID: 18021320 DOI: 10.1111/j.1748-1716.2007.01817.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Ca2+ is the most ubiquitous second messenger found in all cells. Alterations in [Ca2+]i contribute to a wide variety of cellular responses including neurotransmitter release, muscle contraction, synaptogenesis and gene expression. Voltage-dependent Ca2+ channels, found in all excitable cells (Hille 1992), mediate the entry of Ca2+ into cells following depolarization. Ca2+ channels are composed of a large pore-forming subunit, called the alpha1 subunit, and several accessory subunits. Ten different alpha1 subunit genes have been identified and classified into three families, Ca(v1-3) (Dunlap et al. 1995, Catterall 2000). Each alpha1 gene produces a unique Ca2+ channel. Although chromaffin cells express several different types of Ca2+ channels, this review will focus on the Cav(2.1) and Cav(2.2) channels, also known as P/Q- and N-type respectively (Nowycky et al. 1985, Llinas et al. 1989b, Wheeler et al. 1994). These channels exhibit physiological and pharmacological properties similar to their neuronal counterparts. N-, P/Q and to a lesser extent R-type Ca2+ channels are known to regulate neurotransmitter release (Hirning et al. 1988, Horne & Kemp 1991, Uchitel et al. 1992, Luebke et al. 1993, Takahashi & Momiyama 1993, Turner et al. 1993, Regehr & Mintz 1994, Wheeler et al. 1994, Wu & Saggau 1994, Waterman 1996, Wright & Angus 1996, Reid et al. 1997). N- and P/Q-type Ca2+ channels are abundant in nerve terminals where they colocalize with synaptic vesicles. Similarly, these channels play a role in neurotransmitter release in chromaffin cells (Garcia et al. 2006). N- and P/Q-type channels are subject to many forms of regulation (Ikeda & Dunlap 1999). This review pays particular attention to the regulation of N- and P/Q-type channels by heterotrimeric G-proteins, interaction with SNARE proteins, and channel inactivation in the context of stimulus-secretion coupling in adrenal chromaffin cells.
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Affiliation(s)
- A P Fox
- Department of Neurobiology, Pharmacology and Physiology, University of Chicago, Chicago, IL 60637, USA.
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25
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Abstract
Tunicamycins are nucleotide sugar analogs produced by several Streptomyces species. In eukaryotes, tunicamycins inhibit UDP-N-acetylglucosamine: dolichol phosphate GlcNAc-1-P transferase (GPT) that catalyzes the first step in protein glycosylation. In bacteria they inhibit UDP-N-acetylmuramoyl-pentapeptide: undecaprenol phosphate MurNAc-pentapeptide-1-P transtransferase (MraY) that catalyzes an early stage in peptidoglycan cell wall assembly. Tunicamycins are substrate analog of GPT and MraY, such that the alphabeta-1'',11'-linked GlcNAc residue of the tunicamycins mimics the transferred GlcNAc-1-phosphate. The unusual structure of tunicamycins, particularly the unique 11-carbon sugar, tunicamine, and the alphabeta-1'',11'-O-glycosidic linkage, suggest its biosynthesis to be unique. This review discusses potential biosyntheses for tunicamycins via the synthesis and conjugation of uridine-5'-aldehyde and UDP-4-keto-N-acetylgalactosamine-5,6-ene and the subsequent formation of the alpha,beta-1'',11' glycosidic linkage.
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Affiliation(s)
- Neil P J Price
- USDA-ARS-NCAUR, Bioproducts and Biocatalysis Research Unit, 1815 North University Street, Peoria, IL 61604, USA.
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26
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da Silva S, Calado S, Lucas C, Aguiar C. Unusual properties of the halotolerant yeast Candida nodaensis Killer toxin, CnKT. Microbiol Res 2007; 163:243-51. [PMID: 17761407 DOI: 10.1016/j.micres.2007.04.002] [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: 01/15/2007] [Revised: 03/22/2007] [Accepted: 04/08/2007] [Indexed: 10/22/2022]
Abstract
CnKT, the Killer toxin from the extreme halotolerant yeast Candida nodaensis, presents a strong salt-stimulated phenotype and is a resilient toxin, able to cope with very diverse and aggressive environmental conditions. This zymocin is active in a broad range of pH and temperature and tolerates freezing and conservation for long periods of time. CnKT stability is increased under very high ionic strength and its activity is stimulated by sodium ions, which might interfere in the zymocin structure/stability. All these characteristics make CnKT a promising candidate for several biotechnological applications, e.g. in the high-salt food products preservation from spoilage by other yeasts.
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Affiliation(s)
- Sónia da Silva
- Centro de Biologia (CB-UM)/Departamento de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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27
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Zhao Y, Sharp GWG, Straub SG. The inhibitors of protein acylation, cerulenin and tunicamycin, increase voltage-dependent Ca(2+) currents in the insulin-secreting INS 832/13 cell. Biochem Pharmacol 2007; 74:273-80. [PMID: 17548064 PMCID: PMC2065765 DOI: 10.1016/j.bcp.2007.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2006] [Revised: 03/23/2007] [Accepted: 04/06/2007] [Indexed: 11/23/2022]
Abstract
As it has been suggested that protein acylation plays a role in nutrient stimulus-secretion coupling in the pancreatic beta-cell, we examined the insulin-secreting INS 832/13 beta-cell line for evidence that protein acylation was involved. The perforated whole-cell configuration was employed to voltage-clamp INS 832/13 cells. Voltage pulses were applied and Ca(2+) currents measured in the presence and absence of the protein acylation inhibitors cerulenin and tunicamycin. Both inhibitors enhanced the peak amplitude of I(Ca,L). Both increased the peak inward current in the range between -40 and +30mV and shifted the apparent maximum current by 10mV in the hyperpolarizing direction without affecting the activation threshold of -40mV. The two drugs had qualitatively and quantitatively similar effects. Steady-state activation curves revealed that cerulenin and tunicamycin shifted the activation curves in the hyperpolarization direction. Activation time constants were significantly reduced in the presence of both drugs. The Ca(2+) charge influx was increased by the drugs at all potentials tested. In contrast to these effects on the L-type Ca(2+) channel, the two inhibitors of protein acylation had no effect on the ATP-sensitive K(+) channel. The results suggest that protein acylation exerts a tonic inhibitory effect on L-type Ca(2+) channel function in the insulin-secreting beta-cell.
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Affiliation(s)
- Ying Zhao
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401 USA
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28
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Straub SG, Sharp GWG. Inhibition of insulin secretion by cerulenin might be due to impaired glucose metabolism. Diabetes Metab Res Rev 2007; 23:146-51. [PMID: 16705622 DOI: 10.1002/dmrr.649] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Cerulenin, an inhibitor of protein acylation, has been used as a tool to study the potential role of protein acylation in a variety of activities in different cells, and in stimulus-secretion coupling in pancreatic islets and clonal beta-cells. METHODS In the present study we investigated its effects on stimulated insulin secretion, glucose metabolism and utilization, oxygen consumption and ATP levels. RESULTS In isolated rat pancreatic islets, cerulenin pre-treatment (100 microM) inhibited insulin secretion in response to glucose, and to the non-hydrolysable analogue of leucine, aminobicyclo-[2,2,1]heptane-2-carboxylic acid (BCH). These data are in accord with the hypothesis that protein acylation could be involved in the stimulation of insulin secretion. However, we also found that cerulenin profoundly decreased glucose oxidation, glucose utilization, oxygen consumption and ATP levels. Consequently, decreased metabolism provides an alternative mechanism to inhibition of protein acylation that could explain the inhibition of insulin secretion by cerulenin. CONCLUSIONS Inhibition of insulin secretion by cerulenin can no longer be taken as evidence in favour of a role for protein acylation in the control of insulin release. As protein acylation is known to be involved in the normal functioning of proteins in stimulus-secretion coupling and exocytosis, more direct approaches to understand its role(s) are required.
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Affiliation(s)
- Susanne G Straub
- The Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
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29
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Resh MD. Use of analogs and inhibitors to study the functional significance of protein palmitoylation. Methods 2006; 40:191-7. [PMID: 17012032 PMCID: PMC1712572 DOI: 10.1016/j.ymeth.2006.04.013] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2006] [Accepted: 04/21/2006] [Indexed: 11/19/2022] Open
Abstract
Covalent attachment of palmitate to proteins is a post-translational modification that exerts diverse effects on protein localization and function. The three key technical approaches required for an investigator to determine the role of palmitoylation of your favorite palmitoylated protein (YFPP) are methods to: (1) detect YFPP palmitoylation; (2) alter or inhibit palmitoylation of YFPP; (3) determine the functional significance of altered YFPP palmitoylation. Here, I describe experimental methods to address these three issues. Both radioactive (radiolabeling with [(3)H]palmitate or (125)I-IC16 palmitate) and non-radioactive (chemical labeling and mass spectrometry) methods to detect palmitoylated proteins are presented. Next, techniques to inhibit protein palmitoylation are described. These include site specific mutagenesis, and treatment of cells with inhibitors of protein palmitoylation, including 2-bromopalmitate, cerulenin, and tunicamycin. Alternative methods to replace palmitate with other fatty acids are also presented. Finally, general approaches to determining the effect of altered palmitoylation status on YFPP association with membranes and lipid rafts, as well as signal transduction, are described.
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Affiliation(s)
- Marilyn D Resh
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, Box 143, New York, NY 10021, USA.
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30
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Charest PG, Bouvier M. Palmitoylation of the V2 vasopressin receptor carboxyl tail enhances beta-arrestin recruitment leading to efficient receptor endocytosis and ERK1/2 activation. J Biol Chem 2003; 278:41541-51. [PMID: 12900404 DOI: 10.1074/jbc.m306589200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A large number of G protein-coupled receptors are palmitoylated on cysteine residues located in their carboxyl tail, but the general role of this post-translational modification remains poorly understood. Here we show that preventing palmitoylation of the V2 vasopressin receptor, by site-directed mutagenesis of cysteines 341 and 342, significantly delayed and decreased both agonist-promoted receptor endocytosis and mitogen-activated protein kinase activation. Pharmacological blockade of receptor endocytosis is without effect on the vasopressin-stimulated mitogen-activated protein kinase activity, excluding the possibility that the reduced kinase activation mediated by the palmitoylation-less mutant could result from altered receptor endocytosis. In contrast, two dominant negative mutants of beta-arrestin which inhibit receptor endocytosis also attenuated vasopressin-stimulated mitogen-activated protein kinase activity, suggesting that the scaffolding protein, beta-arrestin, represents the common link among receptor palmitoylation, endocytosis, and kinase activation. Coimmunoprecipitation and bioluminescence resonance energy transfer experiments confirmed that inhibiting receptor palmitoylation considerably reduced the vasopressin-stimulated recruitment of beta-arrestin to the receptor. Interestingly, the changes in beta-arrestin recruitment kinetics were similar to those observed for vasopressin-stimulated receptor endocytosis and mitogen-activated protein kinase activation. Taken together the results indicate that palmitoylation enhances the recruitment of beta-arrestin to the activated V2 vasopressin receptor thus facilitating processes requiring the scaffolding action of beta-arrestin.
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Affiliation(s)
- Pascale G Charest
- Department of Biochemistry and Groupe de Recherche sur le Système Nerveux Autonome, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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31
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Qanbar R, Bouvier M. Role of palmitoylation/depalmitoylation reactions in G-protein-coupled receptor function. Pharmacol Ther 2003; 97:1-33. [PMID: 12493533 DOI: 10.1016/s0163-7258(02)00300-5] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
G-protein-coupled receptors (GPCRs) constitute one of the largest protein families in the human genome. They are subject to numerous post-translational modifications, including palmitoylation. This review highlights the dynamic nature of palmitoylation and its role in GPCR expression and function. The palmitoylation of other proteins involved in GPCR signaling, such as G-proteins, regulators of G-protein signaling, and G-protein-coupled receptor kinases, is also discussed.
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Affiliation(s)
- Riad Qanbar
- Département de Biochimie, Université de Montréal, C.P. 6128 Succursale Centre-Ville, 2900 Edouard Montpetit, Montreál, Quebec, Canada H3C 3J7
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32
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DeJesus G, Bizzozero OA. Effect of 2-fluoropalmitate, cerulenin and tunicamycin on the palmitoylation and intracellular translocation of myelin proteolipid protein. Neurochem Res 2002; 27:1669-75. [PMID: 12515321 DOI: 10.1023/a:1021643229028] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We have investigated the effect of documented protein palmitoylation inhibitors on the fatty acylation and intracellular transport of myelin proteolipid protein (PLP). To this end, brain slices from 20-day-old rats were incubated with either [3H]palmitate or [3H]leucine in the presence or absence of various concentrations of 2-fluoropalmitate (FP), cerulenin (CER), or tunicamycin (TM). FP (> or = 10 microM) decreased the cellular uptake of [3H]palmitate and consequently reduced the labeling of palmitoyl-CoA, glycerolipids and PLP. CER (> or = 1 mM) reduced the palmitoylation of PLP with a concomitant decline in protein thiols. Consistent with being a fatty acyl-CoA analogue, TM (> or = 200 microM) diminished the palmitoylation of PLP and lipids while increasing the amount of [3H]palmitoyl-CoA. Although both CER and TM decreased protein palmitoylation, only the latter affected the appearance of newly synthesized PLP into myelin. Because TM, but not CER, also reduced the formation of lipids, it is concluded that palmitoylation is not required for intracellular transport. Finally, comparison of the effect of TM in brain slices and in a cell-free system suggests that palmitoylation of PLP in whole cells may be an enzymatic process.
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Affiliation(s)
- Gisela DeJesus
- Department of Cell Biology and Physiology, University of New Mexico-School of Medicine, Albuquerque, New Mexico 87131-5218, USA
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33
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Liang X, Lu Y, Neubert TA, Resh MD. Mass spectrometric analysis of GAP-43/neuromodulin reveals the presence of a variety of fatty acylated species. J Biol Chem 2002; 277:33032-40. [PMID: 12105219 DOI: 10.1074/jbc.m204607200] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
GAP-43 (neuromodulin) is a protein kinase C substrate that is abundant in developing and regenerating neurons. Thioester-linked palmitoylation at two cysteines near the GAP-43 N terminus has been implicated in directing membrane binding. Here, we use mass spectrometry to examine the stoichiometry of palmitoylation and the molecular identity of the fatty acid(s) attached to GAP-43 in vivo. GAP-43 expressed in either PC12 or COS-1 cells was acetylated at the N-terminal methionine. Approximately 35% of the N-terminal GAP-43 peptides were also modified by palmitate and/or stearate on Cys residues. Interestingly, a variety of acylated species was detected, in which one of the Cys residues was acylated by either palmitate or stearate, or both Cys residues were acylated by palmitates or stearates or a combination of palmitate and stearate. Depalmitoylation of membrane-bound GAP-43 did not release the protein from the membrane, implying that additional forces function to maintain membrane binding. Indeed, mutation of four basic residues within the N-terminal domain of GAP-43 dramatically reduced membrane localization of GAP-43 without affecting palmitoylation. These data reveal the heterogeneous nature of S-acylation in vivo and illustrate the power of mass spectrometry for identification of key regulatory protein modifications.
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Affiliation(s)
- Xiquan Liang
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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34
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The neural cell adhesion molecule regulates cell-surface delivery of G-protein-activated inwardly rectifying potassium channels via lipid rafts. J Neurosci 2002. [PMID: 12177211 DOI: 10.1523/jneurosci.22-16-07154.2002] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mice deficient in the neural cell adhesion molecule (NCAM) exhibit increased anxiety and anxiolytic sensitivity to serotonin 5-HT1A receptor agonists. Here, we investigate the relationship between NCAM and 5-HT1A receptor signaling pathways modulating G-protein-activated inwardly rectifying K+ (Kir3) channels. When studying this relationship in cultured hippocampal neurons, we observed that in cells from NCAM-deficient mice, inwardly rectifying K+ (Kir3) currents were increased compared with wild-type controls. Analysis of this modulatory mechanism in Xenopus oocytes and Chinese hamster ovary (CHO) cells revealed that the recombinantly expressed major transmembrane isoforms NCAM140 and NCAM180 specifically reduced inward currents generated by neuronal Kir3.1/3.2 and Kir3.1/3.3 but not by cardiac Kir3.1/3.4 channels. Using fluorescence measurements and surface biotinylation assays, we show that this effect was caused by a reduced surface localization of Kir3 channels. Furthermore, expression of flag-tagged Kir3 channels in cultured neurons of NCAM-deficient mice resulted in a higher transport of these channels into neurites and a higher cell-surface localization compared with wild-type neurons. Neuronal Kir3 channels and NCAM isoforms are associated with cholesterol-rich microdomains (lipid rafts) in CHO cells and in isolated brain membranes. Mutational and pharmacological disruption of the lipid raft association of NCAM140 normalizes surface delivery of channels. We conclude that the transmembrane isoforms of NCAM reduce the transport of Kir3 channels to the cell surface via lipid rafts. Thus, regulation of Kir3 channel activity by NCAM may represent a novel mechanism controlling long-term excitability of neurons.
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35
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Niethammer P, Delling M, Sytnyk V, Dityatev A, Fukami K, Schachner M. Cosignaling of NCAM via lipid rafts and the FGF receptor is required for neuritogenesis. J Cell Biol 2002; 157:521-32. [PMID: 11980923 PMCID: PMC2173281 DOI: 10.1083/jcb.200109059] [Citation(s) in RCA: 222] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2001] [Revised: 03/15/2002] [Accepted: 03/18/2002] [Indexed: 01/06/2023] Open
Abstract
The neural cell adhesion molecule (NCAM) has been reported to stimulate neuritogenesis either via nonreceptor tyrosine kinases or fibroblast growth factor (FGF) receptor. Here we show that lipid raft association of NCAM is crucial for activation of the nonreceptor tyrosine kinase pathway and induction of neurite outgrowth. Transfection of hippocampal neurons of NCAM-deficient mice revealed that of the three major NCAM isoforms only NCAM140 can act as a homophilic receptor that induces neurite outgrowth. Disruption of NCAM140 raft association either by mutation of NCAM140 palmitoylation sites or by lipid raft destruction attenuates activation of the tyrosine focal adhesion kinase and extracellular signal-regulated kinase 1/2, completely blocking neurite outgrowth. Likewise, NCAM-triggered neurite outgrowth is also completely blocked by a specific FGF receptor inhibitor, indicating that cosignaling via raft-associated kinases and FGF receptor is essential for neuritogenesis.
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Affiliation(s)
- Philipp Niethammer
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, D-20246 Hamburg, Germany
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36
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Parat MO, Stachowicz RZ, Fox PL. Oxidative stress inhibits caveolin-1 palmitoylation and trafficking in endothelial cells. Biochem J 2002; 361:681-8. [PMID: 11802799 PMCID: PMC1222352 DOI: 10.1042/0264-6021:3610681] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During normal and pathological conditions, endothelial cells (ECs) are subjected to locally generated reactive oxygen species, produced by themselves or by other vessel wall cells. In excess these molecules cause oxidative injury to the cell but at moderate levels they might modulate intracellular signalling pathways. We have investigated the effect of oxidative stress on the palmitoylation and trafficking of caveolin-1 in bovine aortic ECs. Exogenous H2O2 did not alter the intracellular localization of caveolin-1 in ECs. However, metabolic labelling experiments showed that H2O2 inhibited the trafficking of newly synthesized caveolin-1 to membrane raft domains. Several mechanisms potentially responsible for this inhibition were examined. Impairment of caveolin-1 synthesis by H2O2 was not responsible for diminished trafficking. Similarly, the inhibition was independent of H2O2-induced caveolin-1 phosphorylation as shown by the markedly different concentration dependences. We tested the effect of H2O2 on palmitoylation of caveolin-1 by the incorporation of [3H]palmitic acid. Exposure of ECs to H2O2 markedly inhibited the palmitoylation of caveolin-1. Comparable inhibition was observed after treatment of cells with H2O2 delivered either as a bolus or by continuous delivery with glucose and glucose oxidase. Kinetic studies showed that H2O2 did not alter the rate of caveolin-1 depalmitoylation but instead decreased the 'on-rate' of palmitoylation. Together these results show for the first time the modulation of protein palmitoylation by oxidative stress, and suggest a cellular mechanism by which stress might influence caveolin-1-dependent cell activities such as the concentration of signalling proteins and cholesterol trafficking.
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Affiliation(s)
- Marie-Odile Parat
- Department of Cell Biology, The Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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37
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Lehrman MA. Oligosaccharide-based information in endoplasmic reticulum quality control and other biological systems. J Biol Chem 2001; 276:8623-6. [PMID: 11254652 DOI: 10.1074/jbc.r100002200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- M A Lehrman
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041, USA.
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38
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Bizzozero OA, Bixler HA, Pastuszyn A. Structural determinants influencing the reaction of cysteine-containing peptides with palmitoyl-coenzyme A and other thioesters. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1545:278-88. [PMID: 11342053 DOI: 10.1016/s0167-4838(00)00291-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Non-enzymatic thioesterification of specific cysteinyl peptides with fatty acyl-CoA has been previously demonstrated in both liposomes and aqueous medium. To identify the molecular basis for the differential reactivity of polypeptides in aqueous solutions, 26 synthetic cysteinyl peptides encompassing the palmitoylation sites of well known proteins (protein zero, proteolipid protein, beta-adrenergic receptor, p21(K-ras), transferrin receptor, CD-4 and SNAP-25) and six small thiol compounds were incubated separately with [3H]palmitoyl-CoA, [14C]acetyl-CoA and p-nitrophenyl thioacetate (NPTA). For each peptide, both the observed reaction rate constant at pH 7.5 and the pH-independent rate constant (k(2)) were calculated, and reactivity of the attacking sulfhydryl group was characterized using the Brønsted equation (log k(2)=beta(nuc) pK(a)+C). In general, peptides bearing basic and aromatic amino acid residues showed the lowest thiol pK(a)s, and consequently displayed the highest acylation rates. Reaction with palmitoyl-CoA was complicated to analyze because of the variable partition of peptides in the acyl chain donor/detergent micelles. In contrast, a linear Brønsted relationship was found for the reaction of the peptides with the water-soluble acetyl-CoA (beta(nuc)=0.59). A similar beta(nuc) value was obtained with the neutral NPTA, indicating that electronic effects other than those responsible for the acid-base properties of the thiol are less important. Thus, the concentration of the thiolate anion appears to be the major factor influencing the rate of the nucleophilic substitution reaction. These findings and the fact that the acylation sites in most proteins are surrounded by basic amino acids may partially explain the specificity of non-enzymatic palmitoylation regarding the acceptor sequences.
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Affiliation(s)
- O A Bizzozero
- Department of Cell Biology and Physiology, University of New Mexico-Health Sciences Center, Albuquerque, NM 87131, USA.
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39
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Hurley JH, Cahill AL, Currie KP, Fox AP. The role of dynamic palmitoylation in Ca2+ channel inactivation. Proc Natl Acad Sci U S A 2000; 97:9293-8. [PMID: 10900273 PMCID: PMC16861 DOI: 10.1073/pnas.160589697] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
N- and P/Q-type Ca(2+) channels regulate a number of critical physiological processes including synaptic transmission and hormone secretion. These Ca(2+) channels are multisubunit proteins, consisting of a pore-forming alpha(1), and accessory beta and alpha(2)delta subunits each encoded by multiple genes and splice variants. beta subunits alter current amplitude and kinetics. The beta(2a) subunit is associated with slowed inactivation, an effect that requires the palmitoylation of two N-terminal cysteine residues in beta(2a). In the current manuscript, we studied steady state inactivation properties of native N- and P/Q-type Ca(2+) channels and recombinant N-type Ca(2+) channels. When bovine alpha(1B) and beta(2a) and human alpha(2)delta were coexpressed in tsA 201 cells, we observed significant variations in inactivation; some cells exhibited virtually no inactivation as the holding potential was altered whereas others exhibited significant inactivation. A similar variability in inactivation was observed in native channels from bovine chromaffin cells. In individual chromaffin cells, the amount of inactivation exhibited by N-type channels was correlated with the inactivation of P/Q-type channels, suggesting a shared mechanism. Our results with recombinant channels with known beta subunit composition indicated that inactivation could be dynamically regulated, possibly by alterations in beta subunit palmitoylation. Tunicamycin, which inhibits palmitoylation, increased steady-state inactivation of Ca(2+) channels in chromaffin cells. Cerulenin, another drug that inhibits palmitoylation, also increased inactivation. Tunicamycin produced a similar effect on recombinant N-type Ca(2+) channels containing beta(2a) but not beta(2b) or beta(2a) subunits mutated to be palmitoylation deficient. Our results suggest that Ca(2+) channels containing beta(2a) subunits may be regulated by dynamic palmitoylation.
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Affiliation(s)
- J H Hurley
- Department of Neurobiology, Pharmacology, and Physiology, University of Chicago, 947 East 58th Street, Chicago, IL 60637, USA
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40
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Veit M, Becher A, Ahnert-Hilger G. Synaptobrevin 2 is palmitoylated in synaptic vesicles prepared from adult, but not from embryonic brain. Mol Cell Neurosci 2000; 15:408-16. [PMID: 10845776 DOI: 10.1006/mcne.1999.0830] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuronal SNARE-proteins such as synaptobrevin, SNAP 25, and synaptotagmin are key players during neurosecretion. So far palmitoylation of SNAP-25 and synaptotagmin 1 have been described in vivo. Here we have analyzed palmitoylation of the SNARE-proteins synaptobrevin 2 and synaptotagmin in vitro using synaptosomal and synaptic vesicle preparations from rat brain. Labeling of synaptic vesicles prepared from adult brain with [3H]palmitate revealed synaptobrevin 2 besides synaptotagmin 1 as major palmitoylated proteins. [3H]Palmitoylation of synaptobrevin 2 was resistant to chloroform/methanol extraction, but sensitive to reducing agents indicating a covalent fatty acid bond to cysteine residues. Palmitoylation of synaptobrevin 2 was also confirmed using endogenous synaptobrevin 2 present in PC-12 cells and synaptobrevin 2 expressed with a vacciniavirus system in Cos cells. In contrast to the situation seen with membrane preparations obtained from adult brain, synaptic vesicles prepared from embryonic rat brain did not support [3H]palmitoylation of synaptobrevin and synaptotagmin. These results suggest, that both synaptobrevin 2 and synaptotagmin were efficiently palmitoylated from mature synaptic vesicles. However, at least one component of the palmitoylation machinery is developmentally upregulated.
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Affiliation(s)
- M Veit
- Department of Immunology and Molecular Biology, Free University, Berlin, Germany.
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41
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Koziak K, Kaczmarek E, Kittel A, Sévigny J, Blusztajn JK, Schulte Am Esch J, Imai M, Guckelberger O, Goepfert C, Qawi I, Robson SC. Palmitoylation targets CD39/endothelial ATP diphosphohydrolase to caveolae. J Biol Chem 2000; 275:2057-62. [PMID: 10636909 DOI: 10.1074/jbc.275.3.2057] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ectonucleotidases influence purinergic receptor function by the hydrolysis of extracellular nucleotides. CD39 is an integral membrane protein that is a prototype member of the nucleoside 5'-triphosphate diphosphohydrolase family. The native CD39 protein has two intracytoplasmic and two transmembrane domains. There is a large extracellular domain that undergoes extensive glycosylation and can be post-translationally modified by limited proteolysis. We have identified a potential thioester linkage site for S-acylation within the N-terminal region of CD39 and demonstrate that this region undergoes palmitoylation in a constitutive manner. The covalent lipid modification of this region of the protein appears to be important both in plasma membrane association and in targeting CD39 to caveolae. These specialized plasmalemmal domains are enriched in G protein-coupled receptors and appear to integrate cellular activation events. We suggest that palmitoylation could modulate the function of CD39 in regulating cellular signal transduction pathways.
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Affiliation(s)
- K Koziak
- Department of Medicine, Center for Immunobiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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42
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Marek KW, Vijay IK, Marth JD. A recessive deletion in the GlcNAc-1-phosphotransferase gene results in peri-implantation embryonic lethality. Glycobiology 1999; 9:1263-71. [PMID: 10536042 DOI: 10.1093/glycob/9.11.1263] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Formation of the dolichol oligosaccharide precursor is essential for the production of asparagine- (N-) linked oligosaccharides (N-glycans) in eukaryotic cells. The first step in precursor biosynthesis requires the enzyme UDP-GlcNAc: dolichol phosphate N-acetylglucosamine-1-phosphate transferase (GPT). Without GPT activity, subsequent steps necessary in constructing the oligosaccharide precursor cannot occur. Inhibition of this biosynthetic step using tunicamycin, a GlcNAc analog, produces a deficiency in N-glycosylation in cell lines and embryonic lethality during preimplantation development in vitro, suggesting that N-glycan formation is essential in early embryogenesis. In exploring structure-function relationships among N-glycans, and since tunicamycin has various reported biochemical activities; we have generated a germline deletion in the mouse GPT gene. GPT mutant embryos were analyzed and the phenotypes obtained were compared with previous studies using tunicamycin. We find that embryos homozygous for a deletion in the GPT gene complete preimplantation development and also implant in the uterine epithelium, but die shortly thereafter between days 4-5 postfertilization with cell degeneration apparent among both embryonic and extraembryonic cell types. Of cells derived from these early embryos, neither trophoblast nor embryonic endodermal lineages are able to survive in culture in vitro. These results indicate that GPT function is essential in early embryogenesis and suggest that N-glycosylation is needed for the viability of cells comprising the peri-implantation stage embryo.
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Affiliation(s)
- K W Marek
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093, USA
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43
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Mody N, Hermans E, Nahorski SR, Challiss RA. Inhibition of N-linked glycosylation of the human type 1alpha metabotropic glutamate receptor by tunicamycin: effects on cell-surface receptor expression and function. Neuropharmacology 1999; 38:1485-92. [PMID: 10530810 DOI: 10.1016/s0028-3908(99)00099-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The potential role of N-linked glycosylation of the human type 1alpha metabotropic glutamate (mGlu1alpha) receptor was studied in a recombinant, inducible expression system, where receptor expression was induced in the absence and presence of tunicamycin. In the absence of tunicamycin the mGlu1alpha receptor appeared to be expressed, at least in part, as a dimer consisting of monomers of approx. 145 and 160 KDa relative molecular mass (Mr). In the presence of tunicamycin only a single monomeric protein could be detected approximating the Mr predicted for the human mGlu1alpha receptor based on its primary amino acid sequence (130 KDa). Exposure to tunicamycin during receptor induction did not appear to affect the cell surface expression of the mGlu1alpha receptor as determined immunocytochemically or using a cell-surface biotinylation strategy, but reduced agonist-stimulated phosphoinositide hydrolysis by approximately 50% compared to control cell populations. Our data suggest that non-N-glycosylated human mGlu1alpha receptors can traffic to the cell surface and activate phospholipase C.
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Affiliation(s)
- N Mody
- Department of Cell Physiology and Pharmacology, University of Leicester, UK
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44
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McLaughlin RE, Denny JB. Palmitoylation of GAP-43 by the ER-Golgi intermediate compartment and Golgi apparatus. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1451:82-92. [PMID: 10446390 DOI: 10.1016/s0167-4889(99)00074-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Palmitoylation of the neuronal plasticity protein GAP-43 has previously been shown to occur at the plasma membrane, but the site of initial palmitoylation has not been identified. To identify this organelle we have incubated GAP-43 with various subcellular fractions and have analyzed palmitoylation by the Triton X-114 partitioning method. In vitro-translated [(35)S]methionine-labeled GAP-43 was incubated with plasma membrane, nuclei, mitochondria, Golgi apparatus and a rough microsome preparation that contained the ER-Golgi intermediate compartment (ERGIC), but not plasma membrane or Golgi apparatus. GAP-43 partitioned into Triton X-114 in the presence of plasma membrane, Golgi, and ERGIC membranes, but not nuclei or mitochondria. Partitioning caused by the ERGIC was blocked by pretreatment of the membranes with the palmitoylation inhibitors dithiothreitol, tunicamycin, and low temperature, and by treatment of GAP-43 with iodoacetamide. The time course of partitioning agreed closely with the time course of incorporation of radioactive palmitate into proteins as reported previously. Because the ERGIC has a broad distribution in the cell, our results provide evidence that the ERGIC is the initial site of GAP-43 palmitoylation.
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45
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Patterson SI, Skene JH. A shift in protein S-palmitoylation, with persistence of growth-associated substrates, marks a critical period for synaptic plasticity in developing brain. JOURNAL OF NEUROBIOLOGY 1999; 39:423-37. [PMID: 10363914 DOI: 10.1002/(sici)1097-4695(19990605)39:3<423::aid-neu8>3.0.co;2-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In the mammalian cortex, the initial formation of synaptic connections is followed by a prolonged period during which synaptic circuits are functional, but retain an elevated capacity for activity-dependent remodeling and functional plasticity. During this period, synaptic terminals appear fully mature, morphologically and physiologically. We show here, however, that synaptic terminals during this period are distinguished by their simultaneous accumulation of multiple growth-associated proteins at levels characteristic of axonal growth cones, and proteins involved in synaptic transmitter release at levels characteristic of adult synapses. We show further that newly formed synapses undergo a switch in the dynamic S-palmitoylation of proteins early in the critical period, which includes a large and specific decrease in the palmitoylation of GAP-43 and other major substrates characteristic of growth cones. Previous studies have shown that a similar reduction in ongoing palmitoylation of growth cone proteins is sufficient to stop advancing axons in vitro, suggesting that a developmental switch in protein S-palmitoylation serves to disengage the molecular machinery for axon extension in the absence of local triggers for remodeling during the critical period. Only much later does a decline in the availability of major growth cone components mark the molecular maturation of cortical synapses at the close of the critical period.
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Affiliation(s)
- S I Patterson
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA
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46
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Vitale A, Denecke J. The endoplasmic reticulum-gateway of the secretory pathway. THE PLANT CELL 1999; 11:615-28. [PMID: 10213782 PMCID: PMC144197 DOI: 10.1105/tpc.11.4.615] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Affiliation(s)
- A Vitale
- Istituto Biosintesi Vegetali, Consiglio Nazionale delle Ricerche, via Bassini 15, 20133 Milan, Italy
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47
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Vitale A, Denecke J. The endoplasmic reticulum-gateway of the secretory pathway. THE PLANT CELL 1999. [PMID: 10213782 DOI: 10.2307/3870888] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Affiliation(s)
- A Vitale
- Istituto Biosintesi Vegetali, Consiglio Nazionale delle Ricerche, via Bassini 15, 20133 Milan, Italy
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48
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Abstract
Covalent lipid modifications anchor numerous signalling proteins to the cytoplasmic face of the plasma membrane. These modifications mediate protein-membrane and protein-protein interactions and are often essential for function. Protein palmitoylation, due to its reversible nature, may be particularly important for modulating protein function during cycles of activation and deactivation. Despite intense investigation, the exact functions of protein palmitoylation are not well understood. However, it is clear that palmitoylation can affect a protein's affinity for membranes, subcellular localization, and interactions with other proteins. In this review, recent advances in understanding the functions and mechanisms of protein palmitoylation are discussed, with particular emphasis on how this lipid affects the biochemistry and cell biology of signalling proteins.
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Affiliation(s)
- J T Dunphy
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 S. Euclid, St. Louis, MO 63110, USA
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49
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Qin N, Platano D, Olcese R, Costantin JL, Stefani E, Birnbaumer L. Unique regulatory properties of the type 2a Ca2+ channel beta subunit caused by palmitoylation. Proc Natl Acad Sci U S A 1998; 95:4690-5. [PMID: 9539800 PMCID: PMC22552 DOI: 10.1073/pnas.95.8.4690] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Beta subunits of voltage-gated Ca2+ channels are encoded in four genes and display additional molecular diversity because of alternative splicing. At the functional level, all forms are very similar except for beta2a, which differs in that it does not support prepulse facilitation of alpha1C Ca2+ channels, inhibits voltage-induced inactivation of neuronal alpha1E Ca2+ channels, and is more effective in blocking inhibition of alpha1E channels by G protein-coupled receptors. We show that the distinguishing properties of beta2a, rather than interaction with a distinct site of alpha1, are because of the recently described palmitoylation of cysteines in positions three and four, which also occurs in the Xenopus oocyte. Essentially, all of the distinguishing features of beta2a were lost in a mutant that could not be palmitoylated [beta2a(Cys3,4Ser)]. Because protein palmitoylation is a dynamic process, these findings point to the possibility that regulation of palmitoylation may contribute to activity-dependent neuronal and synaptic plasticity. Evidence is presented that there may exist as many as three beta2 splice variants differing only in their N-termini.
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Affiliation(s)
- N Qin
- Department of Anesthesiology, University of California, Los Angeles, CA 90095-1778, USA
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50
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Gonzalo S, Linder ME. SNAP-25 palmitoylation and plasma membrane targeting require a functional secretory pathway. Mol Biol Cell 1998; 9:585-97. [PMID: 9487128 PMCID: PMC25287 DOI: 10.1091/mbc.9.3.585] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Synaptosomal-associated protein of 25 kDa (SNAP-25) is a palmitoylated membrane protein essential for neurotransmitter release from synaptic terminals. We used neuronal cell lines to study the biosynthesis and posttranslational processing of SNAP-25 to investigate how palmitoylation contributes to the subcellular localization of the protein. SNAP-25 was synthesized as a soluble protein that underwent palmitoylation approximately 20 min after synthesis. Palmitoylation of the protein coincided with its stable membrane association. Treatment of cells with brefeldin A or other disrupters of transport inhibited palmitoylation of newly synthesized SNAP-25 and abolished membrane association. These results demonstrate that the processing of SNAP-25 and its targeting to the plasma membrane depend on an intact transport mechanism along the exocytic pathway. The kinetics of SNAP-25 palmitoylation and membrane association and the sensitivity of these parameters to brefeldin A suggest a novel trafficking pathway for targeting proteins to the plasma membrane. In vitro, SNAP-25 stably associated with membranes was not released from the membrane after chemical deacylation. We propose that palmitoylation of SNAP-25 is required for initial membrane targeting of the protein but that other interactions can maintain membrane association in the absence of fatty acylation.
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Affiliation(s)
- S Gonzalo
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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