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Palmitoylation of the K ATP channel Kir6.2 subunit promotes channel opening by regulating PIP 2 sensitivity. Proc Natl Acad Sci U S A 2020; 117:10593-10602. [PMID: 32332165 DOI: 10.1073/pnas.1918088117] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A physiological role for long-chain acyl-CoA esters to activate ATP-sensitive K+ (KATP) channels is well established. Circulating palmitate is transported into cells and converted to palmitoyl-CoA, which is a substrate for palmitoylation. We found that palmitoyl-CoA, but not palmitic acid, activated the channel when applied acutely. We have altered the palmitoylation state by preincubating cells with micromolar concentrations of palmitic acid or by inhibiting protein thioesterases. With acyl-biotin exchange assays we found that Kir6.2, but not sulfonylurea receptor (SUR)1 or SUR2, was palmitoylated. These interventions increased the KATP channel mean patch current, increased the open time, and decreased the apparent sensitivity to ATP without affecting surface expression. Similar data were obtained in transfected cells, rat insulin-secreting INS-1 cells, and isolated cardiac myocytes. Kir6.2ΔC36, expressed without SUR, was also positively regulated by palmitoylation. Mutagenesis of Kir6.2 Cys166 prevented these effects. Clinical variants in KCNJ11 that affect Cys166 had a similar gain-of-function phenotype, but was more pronounced. Molecular modeling studies suggested that palmitoyl-C166 and selected large hydrophobic mutations make direct hydrophobic contact with Kir6.2-bound PIP2 Patch-clamp studies confirmed that palmitoylation of Kir6.2 at Cys166 enhanced the PIP2 sensitivity of the channel. Physiological relevance is suggested since palmitoylation blunted the regulation of KATP channels by α1-adrenoreceptor stimulation. The Cys166 residue is conserved in some other Kir family members (Kir6.1 and Kir3, but not Kir2), which are also subject to regulated palmitoylation, suggesting a general mechanism to control the open state of certain Kir channels.
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Neviani V, van Deventer S, Wörner TP, Xenaki KT, van de Waterbeemd M, Rodenburg RNP, Wortel IMN, Kuiper JK, Huisman S, Granneman J, van Bergen En Henegouwen PMP, Heck AJR, van Spriel AB, Gros P. Site-specific functionality and tryptophan mimicry of lipidation in tetraspanin CD9. FEBS J 2020; 287:5323-5344. [PMID: 32181977 PMCID: PMC7818406 DOI: 10.1111/febs.15295] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/19/2020] [Accepted: 03/13/2020] [Indexed: 12/18/2022]
Abstract
Lipidation of transmembrane proteins regulates many cellular activities, including signal transduction, cell–cell communication, and membrane trafficking. However, how lipidation at different sites in a membrane protein affects structure and function remains elusive. Here, using native mass spectrometry we determined that wild‐type human tetraspanins CD9 and CD81 exhibit nonstochastic distributions of bound acyl chains. We revealed CD9 lipidation at its three most frequent lipidated sites suffices for EWI‐F binding, while cysteine‐to‐alanine CD9 mutations markedly reduced binding of EWI‐F. EWI‐F binding by CD9 was rescued by mutating all or, albeit to a lesser extent, only the three most frequently lipidated sites into tryptophans. These mutations did not affect the nanoscale distribution of CD9 in cell membranes, as shown by super‐resolution microscopy using a CD9‐specific nanobody. Thus, these data demonstrate site‐specific, possibly conformation‐dependent, functionality of lipidation in tetraspanin CD9 and identify tryptophan mimicry as a possible biochemical approach to study site‐specific transmembrane‐protein lipidation.
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Affiliation(s)
- Viviana Neviani
- Crystal and Structural Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | - Sjoerd van Deventer
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud UMC, Nijmegen, The Netherlands
| | - Tobias P Wörner
- Biomolecular Mass Spectrometry and Proteomics, Department of Chemistry, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands
| | - Katerina T Xenaki
- Cell Biology, Department of Biology, Utrecht University, The Netherlands
| | - Michiel van de Waterbeemd
- Biomolecular Mass Spectrometry and Proteomics, Department of Chemistry, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands
| | - Remco N P Rodenburg
- Crystal and Structural Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | - Inge M N Wortel
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud UMC, Nijmegen, The Netherlands
| | - Jeroen K Kuiper
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud UMC, Nijmegen, The Netherlands
| | - Sofie Huisman
- Crystal and Structural Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | - Joke Granneman
- Crystal and Structural Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | | | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Department of Chemistry, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands
| | - Annemiek B van Spriel
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud UMC, Nijmegen, The Netherlands
| | - Piet Gros
- Crystal and Structural Chemistry, Department of Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
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53
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Oda Y, Sugawara T, Fukata Y, Izumi Y, Otani T, Higashi T, Fukata M, Furuse M. The extracellular domain of angulin-1 and palmitoylation of its cytoplasmic region are required for angulin-1 assembly at tricellular contacts. J Biol Chem 2020; 295:4289-4302. [PMID: 32079676 PMCID: PMC7105312 DOI: 10.1074/jbc.ra119.010491] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 02/13/2020] [Indexed: 12/13/2022] Open
Abstract
Tricellular tight junctions (tTJs) create paracellular barriers at tricellular contacts (TCs), where the vertices of three polygonal epithelial cells meet. tTJs are marked by the enrichment of two types of membrane proteins, tricellulin and angulin family proteins. However, how TC geometry is recognized for tTJ formation remains unknown. In the present study, we examined the molecular mechanism for the assembly of angulin-1 at the TCs. We found that clusters of cysteine residues in the juxtamembrane region within the cytoplasmic domain of angulin-1 are highly palmitoylated. Mutagenesis analyses of the cysteine residues in this region revealed that palmitoylation is essential for localization of angulin-1 at TCs. Consistently, suppression of Asp-His-His-Cys motif-containing palmitoyltransferases expressed in EpH4 cells significantly impaired the TC localization of angulin-1. Cholesterol depletion from the plasma membrane of cultured epithelial cells hampered the localization of angulin-1 at TCs, suggesting the existence of a lipid membrane microdomain at TCs that attracts highly palmitoylated angulin-1. Furthermore, the extracellular domain of angulin-1 was also required for its TC localization, irrespective of the intracellular palmitoylation. Taken together, our findings suggest that both angulin-1's extracellular domain and palmitoylation of its cytoplasmic region are required for its assembly at TCs.
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Affiliation(s)
- Yukako Oda
- Division of Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
| | - Taichi Sugawara
- Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Yuko Fukata
- Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan; Division of Membrane Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Yasushi Izumi
- Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Tetsuhisa Otani
- Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Tomohito Higashi
- Division of Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
| | - Masaki Fukata
- Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan; Division of Membrane Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Mikio Furuse
- Division of Cell Biology, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan; Division of Cell Structure, National Institute for Physiological Sciences, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan; Department of Physiological Sciences, School of Life Science, Graduate University for Advanced Studies, SOKENDAI, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan.
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54
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Assembly of Tight Junction Strands: Claudin-10b and Claudin-3 Form Homo-Tetrameric Building Blocks that Polymerise in a Channel-Independent Manner. J Mol Biol 2020; 432:2405-2427. [DOI: 10.1016/j.jmb.2020.02.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 02/12/2020] [Accepted: 02/28/2020] [Indexed: 02/03/2023]
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55
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Gadalla MR, Abrami L, van der Goot FG, Veit M. Hemagglutinin of Influenza A, but not of Influenza B and C viruses is acylated by ZDHHC2, 8, 15 and 20. Biochem J 2020; 477:285-303. [PMID: 31872235 DOI: 10.1042/bcj20190752] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/15/2019] [Accepted: 12/23/2019] [Indexed: 02/05/2023]
Abstract
Hemagglutinin (HA), a glycoprotein of Influenza A viruses and its proton channel M2 are site-specifically modified with fatty acids. Whereas two cysteines in the short cytoplasmic tail of HA contain only palmitate, stearate is exclusively attached to one cysteine located at the cytoplasmic border of the transmembrane region (TMR). M2 is palmitoylated at a cysteine positioned in an amphiphilic helix near the TMR. The enzymes catalyzing acylation of HA and M2 have not been identified, but zinc finger DHHC domain-containing (ZDHHC) palmitoyltransferases are candidates. We used a siRNA library to knockdown expression of each of the 23 human ZDHHCs in HA-expressing HeLa cells. siRNAs against ZDHHC2 and 8 had the strongest effect on acylation of HA as demonstrated by Acyl-RAC and confirmed by 3H-palmitate labeling. CRISPR/Cas9 knockout of ZDHHC2 and 8 in HAP1 cells, but also of the phylogenetically related ZDHHCs 15 and 20 strongly reduced acylation of group 1 and group 2 HAs and of M2, but individual ZDHHCs exhibit slightly different substrate preferences. These ZDHHCs co-localize with HA at membranes of the exocytic pathway in a human lung cell line. ZDHHC2, 8, 15 and 20 are not required for acylation of the HA-esterase-fusion protein of Influenza C virus that contains only stearate at one transmembrane cysteine. Knockout of these ZDHHCs also did not compromise acylation of HA of Influenza B virus that contains two palmitoylated cysteines in its cytoplasmic tail. Results are discussed with respect to the acyl preferences and possible substrate recognition features of the identified ZDHHCs.
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Affiliation(s)
- Mohamed Rasheed Gadalla
- Institute of Virology, Free University Berlin, 14163 Berlin, Germany
- Department of Virology, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt
| | - Laurence Abrami
- Global Health Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - F Gisou van der Goot
- Global Health Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Michael Veit
- Institute of Virology, Free University Berlin, 14163 Berlin, Germany
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56
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Palmitoylation of Hepatitis C Virus NS2 Regulates Its Subcellular Localization and NS2-NS3 Autocleavage. J Virol 2019; 94:JVI.00906-19. [PMID: 31597774 PMCID: PMC6912101 DOI: 10.1128/jvi.00906-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/02/2019] [Indexed: 12/16/2022] Open
Abstract
Chronic infection with hepatitis C virus (HCV) is a major cause of severe liver diseases responsible for nearly 400,000 deaths per year. HCV NS2 protein is a multifunctional regulator of HCV replication involved in both viral-genome replication and infectious-virus assembly. However, the underlying mechanism that enables the protein to participate in multiple steps of HCV replication remains unknown. In this study, we discovered that NS2 palmitoylation is the master regulator of its multiple functions, including NS2-mediated self-cleavage and HCV envelope protein recruitment to the virus assembly sites, which in turn promote HCV RNA replication and infectious-particle assembly, respectively. This newly revealed information suggests that NS2 palmitoylation could serve as a promising target to inhibit both HCV RNA replication and virus assembly, representing a new avenue for host-targeting strategies against HCV infection. Hepatitis C virus (HCV) nonstructural protein 2 (NS2) is a multifunctional protein implicated in both HCV RNA replication and virus particle assembly. NS2-encoded cysteine protease is responsible for autoprocessing of NS2-NS3 precursor, an essential step in HCV RNA replication. NS2 also promotes HCV particle assembly by recruiting envelope protein 2 (E2) to the virus assembly sites located at the detergent-resistant membranes (DRM). However, the fundamental mechanism regulating multiple functions of NS2 remains unclear. In this study, we discovered that NS2 is palmitoylated at the position 113 cysteine residue (NS2/C113) when expressed by itself in cells and during infectious-HCV replication. Blocking NS2 palmitoylation by introducing an NS2/C113S mutation reduced NS2-NS3 autoprocessing and impaired HCV RNA replication. Replication of the NS2/C113S mutant was restored by inserting an encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) between NS2 and NS3 to separate the two proteins independently of NS2-mediated autoprocessing. These results suggest that NS2 palmitoylation is critical for HCV RNA replication by promoting NS2-NS3 autoprocessing. The NS2/C113S mutation also impaired infectious-HCV assembly, DRM localization of NS2 and E2, and colocalization of NS2 with Core and endoplasmic reticulum lipid raft-associated protein 2 (Erlin-2). In conclusion, our study revealed that two major functions of NS2 involved in HCV RNA replication and virus assembly, i.e., NS2-NS3 autoprocessing and E2 recruitment to the DRM, are regulated by palmitoylation at NS2/C113. Since S-palmitoylation is reversible, NS2 palmitoylation likely allows NS2 to fine tune both HCV RNA replication and infectious-particle assembly. IMPORTANCE Chronic infection with hepatitis C virus (HCV) is a major cause of severe liver diseases responsible for nearly 400,000 deaths per year. HCV NS2 protein is a multifunctional regulator of HCV replication involved in both viral-genome replication and infectious-virus assembly. However, the underlying mechanism that enables the protein to participate in multiple steps of HCV replication remains unknown. In this study, we discovered that NS2 palmitoylation is the master regulator of its multiple functions, including NS2-mediated self-cleavage and HCV envelope protein recruitment to the virus assembly sites, which in turn promote HCV RNA replication and infectious-particle assembly, respectively. This newly revealed information suggests that NS2 palmitoylation could serve as a promising target to inhibit both HCV RNA replication and virus assembly, representing a new avenue for host-targeting strategies against HCV infection.
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57
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Hong C, Choi SH, Kwak M, Jeong B, Ko J, Park HJ, Choi S, Jun JY, So I. TRPC5 channel instability induced by depalmitoylation protects striatal neurons against oxidative stress in Huntington's disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118620. [PMID: 31812495 DOI: 10.1016/j.bbamcr.2019.118620] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/26/2019] [Accepted: 11/30/2019] [Indexed: 12/15/2022]
Abstract
Protein S-palmitoylation, the covalent lipid modification of the side chain of Cys residues with the 16‑carbon fatty acid palmitate, is the most common acylation, and it enhances the membrane stability of ion channels. This post-translational modification (PTM) determines a functional mechanism of ion channel life cycle from maturation and membrane trafficking to localization. Especially, neurodevelopment is regulated by balancing the level of synaptic protein palmitoylation/depalmitoylation. Recently, we revealed the pathological role of the transient receptor potential canonical type 5 (TRPC5) channel in striatal neuronal loss during Huntington's disease (HD), which is abnormally activated by oxidative stress. Here, we report a mechanism of TRPC5 palmitoylation at a conserved cysteine residue, that is critical for intrinsic channel activity. Furthermore, we identified the therapeutic effect of TRPC5 depalmitoylation by enhancing the TRPC5 membrane instability on HD striatal cells in order to lower TRPC5 toxicity. Collectively, these findings suggest that controlling S-palmitoylation of the TRPC5 channel as a potential risk factor can modulate TRPC5 channel expression and activity, providing new insights into a therapeutic strategy for neurodegenerative diseases.
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Affiliation(s)
- Chansik Hong
- Department of Physiology, Chosun University School of Medicine, Kwangju 61452, South Korea.
| | - Seo Hwa Choi
- Department of Physiology, Chosun University School of Medicine, Kwangju 61452, South Korea
| | - Misun Kwak
- Department of Physiology and Institute of Dermatological Science, Seoul National University College of Medicine, Seoul 03080, South Korea
| | - Byeongseok Jeong
- Department of Physiology, Chosun University School of Medicine, Kwangju 61452, South Korea
| | - Juyeon Ko
- Department of Physiology and Institute of Dermatological Science, Seoul National University College of Medicine, Seoul 03080, South Korea
| | - Hyung Joon Park
- Department of Physiology, Chosun University School of Medicine, Kwangju 61452, South Korea
| | - Seok Choi
- Department of Physiology, Chosun University School of Medicine, Kwangju 61452, South Korea
| | - Jae Yeoul Jun
- Department of Physiology, Chosun University School of Medicine, Kwangju 61452, South Korea
| | - Insuk So
- Department of Physiology and Institute of Dermatological Science, Seoul National University College of Medicine, Seoul 03080, South Korea.
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58
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Gadalla MR, Veit M. Toward the identification of ZDHHC enzymes required for palmitoylation of viral protein as potential drug targets. Expert Opin Drug Discov 2019; 15:159-177. [PMID: 31809605 DOI: 10.1080/17460441.2020.1696306] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Introduction: S-acylation is the attachment of fatty acids not only to cysteines of cellular, but also of viral proteins. The modification is often crucial for the protein´s function and hence for virus replication. Transfer of fatty acids is mediated by one or several of the 23 members of the ZDHHC family of proteins. Since their genes are linked to various human diseases, they represent drug targets.Areas covered: The authors explore whether targeting acylation of viral proteins might be a strategy to combat viral diseases. Many human pathogens contain S-acylated proteins; the ZDHHCs involved in their acylation are currently identified. Based on the 3D structure of two ZDHHCs, the regulation and the biochemistry of the palmitolyation reaction and the lipid and protein substrate specificities are discussed. The authors then speculate how ZDHHCs might recognize S-acylated membrane proteins of Influenza virus.Expert opinion: Although many viral diseases can now be treated, the available drugs bind to viral proteins that rapidly mutate and become resistant. To develop inhibitors for the genetically more stable cellular ZDHHCs, their binding sites for viral substrates need to be identified. If only a few cellular proteins are recognized by the same binding site, development of specific inhibitors may have therapeutic potential.
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Affiliation(s)
- Mohamed Rasheed Gadalla
- Institute of Virology, Free University Berlin, Berlin, Germany.,Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Michael Veit
- Institute of Virology, Free University Berlin, Berlin, Germany
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59
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Kordyukova LV, Serebryakova MV, Khrustalev VV, Veit M. Differential S-Acylation of Enveloped Viruses. Protein Pept Lett 2019; 26:588-600. [PMID: 31161979 DOI: 10.2174/0929866526666190603082521] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 12/18/2022]
Abstract
Post-translational modifications often regulate protein functioning. Covalent attachment of long chain fatty acids to cysteine residues via a thioester linkage (known as protein palmitoylation or S-acylation) affects protein trafficking, protein-protein and protein-membrane interactions. This post-translational modification is coupled to membrane fusion or virus assembly and may affect viral replication in vitro and thus also virus pathogenesis in vivo. In this review we outline modern methods to study S-acylation of viral proteins and to characterize palmitoylproteomes of virus infected cells. The palmitoylation site predictor CSS-palm is critically tested against the Class I enveloped virus proteins. We further focus on identifying the S-acylation sites directly within acyl-peptides and the specific fatty acid (e.g, palmitate, stearate) bound to them using MALDI-TOF MS-based approaches. The fatty acid heterogeneity/ selectivity issue attracts now more attention since the recently published 3D-structures of two DHHC-acyl-transferases gave a hint how this might be achieved.
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Affiliation(s)
- Larisa V Kordyukova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | - Marina V Serebryakova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | - Vladislav V Khrustalev
- Department of General Chemistry, Belarusian State Medical University, Minsk 220116, Belarus
| | - Michael Veit
- Institut für Virologie, Vet.-Med. Faculty, Free University Berlin, Berlin 14163, Germany
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60
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Pellicer Martinez MT, Crack JC, Stewart MYY, Bradley JM, Svistunenko DA, Johnston AWB, Cheesman MR, Todd JD, Le Brun NE. Mechanisms of iron- and O 2-sensing by the [4Fe-4S] cluster of the global iron regulator RirA. eLife 2019; 8:e47804. [PMID: 31526471 PMCID: PMC6748827 DOI: 10.7554/elife.47804] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 07/29/2019] [Indexed: 01/05/2023] Open
Abstract
RirA is a global regulator of iron homeostasis in Rhizobium and related α-proteobacteria. In its [4Fe-4S] cluster-bound form it represses iron uptake by binding to IRO Box sequences upstream of RirA-regulated genes. Under low iron and/or aerobic conditions, [4Fe-4S] RirA undergoes cluster conversion/degradation to apo-RirA, which can no longer bind IRO Box sequences. Here, we apply time-resolved mass spectrometry and electron paramagnetic resonance spectroscopy to determine how the RirA cluster senses iron and O2. The data indicate that the key iron-sensing step is the O2-independent, reversible dissociation of Fe2+ from [4Fe-4S]2+ to form [3Fe-4S]0. The dissociation constant for this process was determined as Kd = ~3 µM, which is consistent with the sensing of 'free' iron in the cytoplasm. O2-sensing occurs through enhanced cluster degradation under aerobic conditions, via O2-mediated oxidation of the [3Fe-4S]0 intermediate to form [3Fe-4S]1+. This work provides a detailed mechanistic/functional view of an iron-responsive regulator.
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Affiliation(s)
- Ma Teresa Pellicer Martinez
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Melissa YY Stewart
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | | | - Andrew WB Johnston
- School of Biological SciencesUniversity of East AngliaNorwichUnited Kingdom
| | - Myles R Cheesman
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Jonathan D Todd
- School of Biological SciencesUniversity of East AngliaNorwichUnited Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
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61
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Ernst AM, Toomre D, Bogan JS. Acylation - A New Means to Control Traffic Through the Golgi. Front Cell Dev Biol 2019; 7:109. [PMID: 31245373 PMCID: PMC6582194 DOI: 10.3389/fcell.2019.00109] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/29/2019] [Indexed: 12/22/2022] Open
Abstract
The Golgi is well known to act as center for modification and sorting of proteins for secretion and delivery to other organelles. A key sorting step occurs at the trans-Golgi network and is mediated by protein adapters. However, recent data indicate that sorting also occurs much earlier, at the cis-Golgi, and uses lipid acylation as a novel means to regulate anterograde flux. Here, we examine an emerging role of S-palmitoylation/acylation as a mechanism to regulate anterograde routing. We discuss the critical Golgi-localized DHHC S-palmitoyltransferase enzymes that orchestrate this lipid modification, as well as their diverse protein clients (e.g., MAP6, SNAP25, CSP, LAT, β-adrenergic receptors, GABA receptors, and GLUT4 glucose transporters). Critically, for integral membrane proteins, S-acylation can act as new a “self-sorting” signal to concentrate these cargoes in rims of Golgi cisternae, and to promote their rapid traffic through the Golgi or, potentially, to bypass the Golgi. We discuss this mechanism and examine its potential relevance to human physiology and disease, including diabetes and neurodegenerative diseases.
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Affiliation(s)
- Andreas M Ernst
- Department of Cell Biology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Derek Toomre
- Department of Cell Biology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Jonathan S Bogan
- Department of Cell Biology, Yale School of Medicine, Yale University, New Haven, CT, United States.,Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale School of Medicine, Yale University, New Haven, CT, United States
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62
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Domains of the TF protein important in regulating its own palmitoylation. Virology 2019; 531:31-39. [PMID: 30852269 DOI: 10.1016/j.virol.2019.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 11/23/2022]
Abstract
Sindbis virus particles contain the viral proteins capsid, E1 and E2, and low levels of a small membrane protein called TF. TF is produced during a (-1) programmed ribosomal frameshifting event during the translation of the structural polyprotein. TF from Sindbis virus-infected cells is present in two palmitoylated states, basal and maximal; unpalmitoylated TF is not detectable. Mutagenesis studies demonstrated that without palmitoylation, TF is not incorporated into released virions, suggesting palmitoylation of TF is a regulated step in virus assembly. In this work, we identified Domains within the TF protein that regulate its palmitoylation state. Mutations and insertions in Domain III, a region proposed to be in the cytoplasmic loop of TF, increase levels of unpalmitoylated TF found during an infection but still unpalmitoylated TF was not incorporated into virions. Mutations in Domain IV, the TF unique region, are likely to impact the balance between basal and maximal palmitoylation.
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Rajagopal N, Irudayanathan FJ, Nangia S. Palmitoylation of Claudin-5 Proteins Influences Their Lipid Domain Affinity and Tight Junction Assembly at the Blood–Brain Barrier Interface. J Phys Chem B 2019; 123:983-993. [DOI: 10.1021/acs.jpcb.8b09535] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Nandhini Rajagopal
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse 13244, United States
| | | | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse 13244, United States
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Ko PJ, Dixon SJ. Protein palmitoylation and cancer. EMBO Rep 2018; 19:embr.201846666. [PMID: 30232163 DOI: 10.15252/embr.201846666] [Citation(s) in RCA: 254] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/24/2018] [Accepted: 08/16/2018] [Indexed: 12/11/2022] Open
Abstract
Protein S-palmitoylation is a reversible post-translational modification that alters the localization, stability, and function of hundreds of proteins in the cell. S-palmitoylation is essential for the function of both oncogenes (e.g., NRAS and EGFR) and tumor suppressors (e.g., SCRIB, melanocortin 1 receptor). In mammalian cells, the thioesterification of palmitate to internal cysteine residues is catalyzed by 23 Asp-His-His-Cys (DHHC)-family palmitoyl S-acyltransferases while the removal of palmitate is catalyzed by serine hydrolases, including acyl-protein thioesterases (APTs). These enzymes modulate the function of important oncogenes and tumor suppressors and often display altered expression patterns in cancer. Targeting S-palmitoylation or the enzymes responsible for palmitoylation dynamics may therefore represent a candidate therapeutic strategy for certain cancers.
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Affiliation(s)
- Pin-Joe Ko
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Scott J Dixon
- Department of Biology, Stanford University, Stanford, CA, USA
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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: 6.6] [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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