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Kimura-Yoshida C, Mochida K, Kanno SI, Matsuo I. USP39 is essential for mammalian epithelial morphogenesis through upregulation of planar cell polarity components. Commun Biol 2022; 5:378. [PMID: 35440748 PMCID: PMC9018712 DOI: 10.1038/s42003-022-03254-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Previously, we have shown that the translocation of Grainyhead-like 3 (GRHL3) transcription factor from the nucleus to the cytoplasm triggers the switch from canonical Wnt signaling for epidermal differentiation to non-canonical Wnt signaling for epithelial morphogenesis. However, the molecular mechanism that underlies the cytoplasmic localization of GRHL3 protein and that activates non-canonical Wnt signaling is not known. Here, we show that ubiquitin-specific protease 39 (USP39), a deubiquitinating enzyme, is involved in the subcellular localization of GRHL3 as a potential GRHL3-interacting protein and is necessary for epithelial morphogenesis to up-regulate expression of planar cell polarity (PCP) components. Notably, mouse Usp39-deficient embryos display early embryonic lethality due to a failure in primitive streak formation and apico-basal polarity in epiblast cells, resembling those of mutant embryos of the Prickle1 gene, a crucial PCP component. Current findings provide unique insights into how differentiation and morphogenesis are coordinated to construct three-dimensional complex structures via USP39. The ubiquitin specific protease 39 (USP39) interacts with the transcription factor and cytoplasmic regulator of planar cell polarity (PCP), Grainyheadlike 3 (Grhl3). USP39-dependent PCP gene upregulation contributes to epithelial morphogenesis.
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Affiliation(s)
- Chiharu Kimura-Yoshida
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840, Murodo-cho, Izumi, Osaka, 594-1101, Japan.
| | - Kyoko Mochida
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840, Murodo-cho, Izumi, Osaka, 594-1101, Japan
| | - Shin-Ichiro Kanno
- IDAC Fellow Research Group for DNA Repair and Dynamic Proteome, Institute of Development, Aging and Cancer, Tohoku University, Sendai, 980-8575, Japan
| | - Isao Matsuo
- Department of Molecular Embryology, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, 840, Murodo-cho, Izumi, Osaka, 594-1101, Japan. .,Department of Pediatric and Neonatal-Perinatal Research, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan.
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Batishchev OV. Physico-Chemical Mechanisms of the Functioning of Membrane-Active Proteins of Enveloped Viruses. BIOCHEMISTRY (MOSCOW) SUPPLEMENT. SERIES A, MEMBRANE AND CELL BIOLOGY 2022; 16:247-260. [PMCID: PMC9734521 DOI: 10.1134/s1990747822050038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/01/2022] [Accepted: 06/02/2022] [Indexed: 12/14/2022]
Abstract
Over the past few years, the attention of the whole world has been riveted to the emergence of new dangerous strains of viruses, among which a special place is occupied by coronaviruses that have overcome the interspecies barrier in the past 20 years: SARS viruses (SARS), Middle East respiratory syndrome (MERS), as well as a new coronavirus infection (SARS-CoV-2), which caused the largest pandemic since the Spanish flu in 1918. Coronaviruses are members of a class of enveloped viruses that have a lipoprotein envelope. This class also includes such serious pathogens as human immunodeficiency virus (HIV), hepatitis, Ebola virus, influenza, etc. Despite significant differences in the clinical picture of the course of disease caused by enveloped viruses, they themselves have a number of characteristic features, which determine their commonality. Regardless of the way of penetration into the cell—by endocytosis or direct fusion with the cell membrane—enveloped viruses are characterized by the following stages of interaction with the target cell: binding to receptors on the cell surface, interaction of the surface glycoproteins of the virus with the membrane structures of the infected cell, fusion of the lipid envelope of the virion with plasma or endosomal membrane, destruction of the protein capsid and its dissociation from the viral nucleoprotein. Subsequently, within the infected cell, the newly synthesized viral proteins must self-assemble on various membrane structures to form a progeny virion. Thus, both the initial stages of viral infection and the assembly and release of new viral particles are associated with the activity of viral proteins in relation to the cell membrane and its organelles. This review is devoted to the analysis of physicochemical mechanisms of functioning of the main structural proteins of a number of enveloped viruses in order to identify possible strategies for the membrane activity of such proteins at various stages of viral infection of the cell.
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Affiliation(s)
- O. V. Batishchev
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 119071 Moscow, Russia
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3
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Husby ML, Stahelin RV. Negative-sense RNA viruses: An underexplored platform for examining virus-host lipid interactions. Mol Biol Cell 2021; 32:pe1. [PMID: 34570653 PMCID: PMC8684762 DOI: 10.1091/mbc.e19-09-0490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 07/20/2021] [Accepted: 07/30/2021] [Indexed: 11/11/2022] Open
Abstract
Viruses are pathogenic agents that can infect all varieties of organisms, including plants, animals, and humans. These microscopic particles are genetically simple as they encode a limited number of proteins that undertake a wide range of functions. While structurally distinct, viruses often share common characteristics that have evolved to aid in their infectious life cycles. A commonly underappreciated characteristic of many deadly viruses is a lipid envelope that surrounds their protein and genetic contents. Notably, the lipid envelope is formed from the host cell the virus infects. Lipid-enveloped viruses comprise a diverse range of pathogenic viruses, which often lead to high fatality rates and many lack effective therapeutics and/or vaccines. This perspective primarily focuses on the negative-sense RNA viruses from the order Mononegavirales, which obtain their lipid envelope from the host plasma membrane. Specifically, the perspective highlights the common themes of host cell lipid and membrane biology necessary for virus replication, assembly, and budding.
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Affiliation(s)
- Monica L. Husby
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907
| | - Robert V. Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology and the Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907
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4
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Kawabe H, Stegmüller J. The role of E3 ubiquitin ligases in synapse function in the healthy and diseased brain. Mol Cell Neurosci 2021; 112:103602. [DOI: 10.1016/j.mcn.2021.103602] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/06/2021] [Accepted: 02/02/2021] [Indexed: 02/08/2023] Open
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5
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Differential Behaviours and Preferential Bindings of Influenza Nucleoproteins on Importins-α. Viruses 2020; 12:v12080834. [PMID: 32751671 PMCID: PMC7472415 DOI: 10.3390/v12080834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/23/2020] [Accepted: 07/27/2020] [Indexed: 12/20/2022] Open
Abstract
Influenza viruses are negative single-stranded RNA viruses with nuclear transcription and replication. They enter the nucleus by using the cellular importin-α/-β nuclear import machinery. Influenza nucleoproteins from influenza A, B, C and D viruses possess a nuclear localization signal (NLS) localized on an intrinsically disordered extremity (NPTAIL). In this paper, using size exclusion chromatography (SEC), SEC-multi-angle laser light scattering (SEC-MALLS) analysis, surface plasmon resonance (SPR) and fluorescence anisotropy, we provide the first comparative study designed to dissect the interaction between the four NPTAILs and four importins-α identified as partners. All interactions between NPTAILs and importins-α have high association and dissociation rates and present a distinct and specific behaviour. D/NPTAIL interacts strongly with all importins-α while B/NPTAIL shows weak affinity for importins-α. A/NPTAIL and C/NPTAIL present preferential importin-α partners. Mutations in B/NPTAIL and D/NPTAIL show a loss of importin-α binding, confirming key NLS residues. Taken together, our results provide essential highlights of this complex translocation mechanism.
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Shtykova EV, Petoukhov MV, Dadinova LA, Fedorova NV, Tashkin VY, Timofeeva TA, Ksenofontov AL, Loshkarev NA, Baratova LA, Jeffries CM, Svergun DI, Batishchev OV. Solution Structure, Self-Assembly, and Membrane Interactions of the Matrix Protein from Newcastle Disease Virus at Neutral and Acidic pH. J Virol 2019; 93:e01450-18. [PMID: 30567981 PMCID: PMC6401449 DOI: 10.1128/jvi.01450-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/10/2018] [Indexed: 11/20/2022] Open
Abstract
Newcastle disease virus (NDV) is an enveloped paramyxovirus. The matrix protein of the virus (M-NDV) has an innate propensity to produce virus-like particles budding from the plasma membrane of the expressing cell without recruiting other viral proteins. The virus predominantly infects the host cell via fusion with the host plasma membrane or, alternatively, can use receptor-mediated endocytic pathways. The question arises as to what are the mechanisms supporting such diversity, especially concerning the assembling and membrane binding properties of the virus protein scaffold under both neutral and acidic pH conditions. Here, we suggest a novel method of M-NDV isolation in physiological ionic strength and employ a combination of small-angle X-ray scattering, atomic force microscopy with complementary structural techniques, and membrane interaction measurements to characterize the solution behavior/structure of the protein as well as its binding to lipid membranes at pH 4.0 and pH 7.0. We demonstrate that the minimal structural unit of the protein in solution is a dimer that spontaneously assembles in a neutral milieu into hollow helical oligomers by repeating the protein tetramers. Acidic pH conditions decrease the protein oligomerization state to the individual dimers, tetramers, and octamers without changing the density of the protein layer and lipid membrane affinity, thus indicating that the endocytic pathway is a possible facilitator of NDV entry into a host cell through enhanced scaffold disintegration.IMPORTANCE The matrix protein of the Newcastle disease virus (NDV) is one of the most abundant viral proteins that regulates the formation of progeny virions. NDV is an avian pathogen that impacts the economics of bird husbandry due to its resulting morbidity and high mortality rates. Moreover, it belongs to the Avulavirus subfamily of the Paramyxoviridae family of Mononegavirales that include dangerous representatives such as respiratory syncytial virus, human parainfluenza virus, and measles virus. Here, we investigate the solution structure and membrane binding properties of this protein at both acidic and neutral pH to distinguish between possible virus entry pathways and propose a mechanism of assembly of the viral matrix scaffold. This work is fundamental for understanding the mechanisms of viral entry as well as to inform subsequent proposals for the possible use of the virus as an adequate template for future drug or vaccine delivery.
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Affiliation(s)
- E V Shtykova
- A. V. Shubnikov Institute of Crystallography of Federal Scientific Research Centre Crystallography and Photonics, Russian Academy of Sciences, Moscow, Russia
- N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - M V Petoukhov
- A. V. Shubnikov Institute of Crystallography of Federal Scientific Research Centre Crystallography and Photonics, Russian Academy of Sciences, Moscow, Russia
- N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
- A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
- EMBL/DESY, Hamburg, Germany
| | - L A Dadinova
- A. V. Shubnikov Institute of Crystallography of Federal Scientific Research Centre Crystallography and Photonics, Russian Academy of Sciences, Moscow, Russia
| | - N V Fedorova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - V Yu Tashkin
- A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
| | - T A Timofeeva
- D. I. Ivanovsky Institute of Virology, FSBI N. F. Gamaleya NRCEM, Ministry of Health of Russian Federation, Moscow, Russian
| | - A L Ksenofontov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - N A Loshkarev
- A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudniy, Russia
| | - L A Baratova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | | | - D I Svergun
- D. I. Ivanovsky Institute of Virology, FSBI N. F. Gamaleya NRCEM, Ministry of Health of Russian Federation, Moscow, Russian
| | - O V Batishchev
- A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology, Dolgoprudniy, Russia
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7
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Baczyk D, Audette MC, Coyaud E, Raught B, Kingdom JC. Spatiotemporal distribution of small ubiquitin-like modifiers during human placental development and in response to oxidative and inflammatory stress. J Physiol 2018; 596:1587-1600. [PMID: 29468681 PMCID: PMC5924830 DOI: 10.1113/jp275288] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 02/05/2018] [Indexed: 12/28/2022] Open
Abstract
Key points The post‐translational modification of target proteins by SUMOylation occurs in response to stressful stimuli in a variety of organ systems. Small ubiquitin‐like modifier (SUMO) isoforms 1–4 have recently been identified in the human placenta, and are upregulated in the major obstetrical complication of pre‐eclampsia. This is the first study to characterize the spatiotemporal distribution of SUMO isoforms and their targets during placental development across gestation and in response to stress induced by pre‐eclampsia and chorioamnionitis. Keratins were identified as major targets of placental SUMOylation. The interaction with SUMOs and cytoskeletal filaments provides evidence for SUMOylation possibly contributing to underlying dysfunctional trophoblast turnover, which is a hallmark feature of pre‐eclampsia. Further understanding the role of individual SUMO isoforms and SUMOylation underlying placental dysfunction may provide a target for a novel therapeutic candidate as an approach for treating pre‐eclampsia complicated with placental pathology.
Abstract SUMOylation is a dynamic, reversible post‐translational modification that regulates cellular protein stability and localization. SUMOylation occurs in response to various stressors, including hypoxia and inflammation, features common in the obstetrical condition of pre‐eclampsia. SUMO isoforms 1–4 have recently been identified in the human placenta, but less is known about their role in response to pre‐eclamptic stress. We hypothesized that SUMOylation components have a unique spatiotemporal distribution during placental development and that their subcellular localization can be further modulated by extra‐cellular stressors. Placental SUMO expression was examined across gestation. First‐trimester human placental explants and JAR cells were subjected to hypoxia or TNF‐α cytokine, and subcellular translocation of SUMOs was monitored. SUMOylation target proteins were elucidated using mass spectrometry and proximity ligation assay. Placental SUMO‐1 and SUMO‐4 were restricted to villous cytotrophoblast cells in first trimester and syncytium by term, while SUMO‐2/3 staining was evenly distributed throughout the trophoblast across gestation. In placental villous explants, oxidative stress induced hyperSUMOylation of SUMO‐1 and SUMO‐4 in the syncytial cytoplasm, whereas SUMO‐2/3 nuclear expression increased. Oxidative stress also upregulated cytoplasmic SUMO‐1 and SUMO‐4 protein expression (P < 0.05), similar to pre‐eclamptic placentas. Keratins were identified as major targets of placental SUMOylation. Oxidative stress increased the cytokeratin‐7 to SUMO‐1 and SUMO‐4 interactions, while inflammatory stress increased its interaction with SUMO‐2/3. Overall, SUMOs display a unique spatiotemporal distribution in normal human placental development. Our data indicate SUMOylation in pre‐eclampsia, which may impair the stability of cytoskeleton filaments and thus promote trophoblast shedding into the maternal circulation in this condition. The post‐translational modification of target proteins by SUMOylation occurs in response to stressful stimuli in a variety of organ systems. Small ubiquitin‐like modifier (SUMO) isoforms 1–4 have recently been identified in the human placenta, and are upregulated in the major obstetrical complication of pre‐eclampsia. This is the first study to characterize the spatiotemporal distribution of SUMO isoforms and their targets during placental development across gestation and in response to stress induced by pre‐eclampsia and chorioamnionitis. Keratins were identified as major targets of placental SUMOylation. The interaction with SUMOs and cytoskeletal filaments provides evidence for SUMOylation possibly contributing to underlying dysfunctional trophoblast turnover, which is a hallmark feature of pre‐eclampsia. Further understanding the role of individual SUMO isoforms and SUMOylation underlying placental dysfunction may provide a target for a novel therapeutic candidate as an approach for treating pre‐eclampsia complicated with placental pathology.
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Affiliation(s)
- Dora Baczyk
- Program in Development and Fetal Health, Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5T3H7, Canada
| | - Melanie C Audette
- Program in Development and Fetal Health, Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5T3H7, Canada.,Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Etienne Coyaud
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G1L7, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, M5G1L7, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, M5G1L7, Canada
| | - John C Kingdom
- Program in Development and Fetal Health, Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5T3H7, Canada.,Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Maternal-Fetal Medicine Division, Department of Obstetrics and Gynecology, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada
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8
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Reprint of: Importins in the maintenance and lineage commitment of ES cells. Neurochem Int 2017; 106:14-23. [PMID: 28550879 DOI: 10.1016/j.neuint.2017.01.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/25/2017] [Accepted: 01/30/2017] [Indexed: 11/23/2022]
Abstract
The nucleus of a eukaryotic cell is separated from the cytoplasm by a nuclear envelope, and nuclear pores within the envelope facilitate nucleocytoplasmic transport and the exchange of information. Gene regulation is a key component of biological activity regulation in the cell. Transcription factors control the expression levels of various genes that are necessary for the maintenance or conversion of cellular states during animal development. Because transcription factor activities determine the extent of transcription of target genes, the number of active transcription factors must be tightly regulated. In this regard, the nuclear translocation of a transcription factor is an important determinant of its activity. Therefore, it is becoming clear that the nucleocytoplasmic transport machinery is involved in cell differentiation and organism development. This review examines the regulation of transcription factors by the nucleocytoplasmic transport machinery in ES cells.
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9
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Posttranslational Modifications in Spermatozoa and Effects on Male Fertility and Sperm Viability. ACTA ACUST UNITED AC 2017; 21:245-256. [DOI: 10.1089/omi.2016.0173] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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10
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Li J, Callegari S, Masucci MG. The Epstein-Barr virus miR-BHRF1-1 targets RNF4 during productive infection to promote the accumulation of SUMO conjugates and the release of infectious virus. PLoS Pathog 2017; 13:e1006338. [PMID: 28414785 PMCID: PMC5413087 DOI: 10.1371/journal.ppat.1006338] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 05/02/2017] [Accepted: 04/06/2017] [Indexed: 12/21/2022] Open
Abstract
Post-translational modification by the Small Ubiquitin-like Modifier (SUMO) regulates a variety of cellular functions, and is hijacked by viruses to remodel the host cell during latent and productive infection. Here we have monitored the activity of the SUMO conjugation machinery in cells productively infected with Epstein-Barr virus (EBV). We found that SUMO2/3 conjugates accumulate during the late phase of the productive virus cycle, and identified several viral proteins as bone fide SUMOylation substrates. Analysis of the mechanism involved in the accumulation of SUMOylated proteins revealed upregulation of several components of the SUMO-conjugation machinery and post-transcriptional downregulation of the SUMO-targeted ubiquitin ligase RNF4. The latter effect was mediated by selective inhibition of RNF4 protein expression by the viral miR-BHRF1-1. Reconstitution of RNF4 in cells expressing an inducible miR-BHRF1-1 sponge or a miR-BHRF1-1 resistant RNF4 was associated with reduced levels of early and late viral proteins and impaired virus release. These findings illustrate a novel strategy for viral interference with the SUMO pathway, and identify the EBV miR-BHRF1-1 and the cellular RNF4 as regulators of the productive virus cycle. We have investigated the activity of the SUMOylation machinery in cells infected with Epstein-Barr virus (EBV), a human herpesvirus that infects B-lymphocytes and is associated with malignancies. We found that activation of the productive virus cycle is accompanied by accumulation of SUMO conjugates, upregulation of components of the SUMO conjugation machinery, and downregulation of the SUMO-targeted ubiquitin ligase RNF4. The decrease of RNF4 is due to post-transcriptional downregulation by miR-BHRF1-1, a member of the BHRF1 microRNA cluster that is upregulated during productive infection. The effect of miR-BHRF1-1 was confirmed in luciferase reported assays, by mutation of the RNF4 3’UTR seed site, by transfection of a synthetic miR-BHRF1-1 mimic, by ectopic expression of miR-BHRF1-1 and by the reversal of RNF4 downregulation in cells expressing a miR-BHRF1-1 sponge. We also found that several early and late viral proteins are bona fide SUMOylation substrates. Reconstitution of RNF4 in productively infected cells was accompanied by proteasome-dependent degradation of the SUMOylated viral protein and by a significantly reduced virus yield. These findings illustrate a new strategy for viral interference with the SUMO pathway, an unexpected contribution of miR-BHRF1-1 to the productive cycle of EBV and a previously unrecognized role of the RNF4 ligase in the regulation of virus production.
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Affiliation(s)
- Jinlin Li
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Simone Callegari
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Maria G. Masucci
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
- * E-mail:
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11
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Importins in the maintenance and lineage commitment of ES cells. Neurochem Int 2017; 105:32-41. [PMID: 28163061 DOI: 10.1016/j.neuint.2017.01.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 01/25/2017] [Accepted: 01/30/2017] [Indexed: 11/23/2022]
Abstract
The nucleus of a eukaryotic cell is separated from the cytoplasm by a nuclear envelope, and nuclear pores within the envelope facilitate nucleocytoplasmic transport and the exchange of information. Gene regulation is a key component of biological activity regulation in the cell. Transcription factors control the expression levels of various genes that are necessary for the maintenance or conversion of cellular states during animal development. Because transcription factor activities determine the extent of transcription of target genes, the number of active transcription factors must be tightly regulated. In this regard, the nuclear translocation of a transcription factor is an important determinant of its activity. Therefore, it is becoming clear that the nucleocytoplasmic transport machinery is involved in cell differentiation and organism development. This review examines the regulation of transcription factors by the nucleocytoplasmic transport machinery in ES cells.
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12
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Puntambekar SS, Nyayanit D, Saxena P, Gadgil CJ. Identification of Unintuitive Features of Sumoylation through Mathematical Modeling. J Biol Chem 2016; 291:9458-68. [PMID: 26861881 PMCID: PMC4850286 DOI: 10.1074/jbc.m115.676122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 01/04/2016] [Indexed: 11/06/2022] Open
Abstract
Sumoylation is a multistep, multienzymatic post-translational modification in which a small ubiquitin-like modifier protein (SUMO) is attached to the target. We present the first mathematical model for sumoylation including enzyme mechanism details such as autosumoylation of E2 and multifunctional nature of SENP. Simulations and analysis reveal three nonobvious properties for the long term response, modeled as an open system: (i) the steady state sumoylation level is robust to variation in several enzyme properties; (ii) even when autosumoylation of E2 results in equal or higher activity, the target sumoylation levels are lower; and (iii) there is an optimal SENP concentration at which steady state target sumoylation level is maximum. These results are qualitatively different for a short term response modeled as a closed system, where e.g. sumoylation always decreases with increasing SENP levels. Simulations with multiple targets suggest that the available SUMO is limiting, indicating a possible explanation for the experimentally observed low fractional sumoylation. We predict qualitative differences in system responses at short post-translational and longer transcriptional time scales. We thus use this mechanism-based model to explain system properties and generate testable hypotheses for existence and mechanism of unexpected responses.
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Affiliation(s)
- Shraddha S Puntambekar
- From the Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory, Pune-411008, and the Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune-411008, and
| | - Dimpal Nyayanit
- From the Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory, Pune-411008, and the Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune-411008, and
| | - Priyanka Saxena
- the Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune-411008, and the CSIR-Institute of Genomics and Integrative Biology, New Delhi 110020, India
| | - Chetan J Gadgil
- From the Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory, Pune-411008, and the Academy of Scientific and Innovative Research (AcSIR), CSIR-NCL Campus, Pune-411008, and the CSIR-Institute of Genomics and Integrative Biology, New Delhi 110020, India
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Alonso A, Greenlee M, Matts J, Kline J, Davis KJ, Miller RK. Emerging roles of sumoylation in the regulation of actin, microtubules, intermediate filaments, and septins. Cytoskeleton (Hoboken) 2015; 72:305-39. [PMID: 26033929 PMCID: PMC5049490 DOI: 10.1002/cm.21226] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/25/2015] [Accepted: 05/27/2015] [Indexed: 12/29/2022]
Abstract
Sumoylation is a powerful regulatory system that controls many of the critical processes in the cell, including DNA repair, transcriptional regulation, nuclear transport, and DNA replication. Recently, new functions for SUMO have begun to emerge. SUMO is covalently attached to components of each of the four major cytoskeletal networks, including microtubule-associated proteins, septins, and intermediate filaments, in addition to nuclear actin and actin-regulatory proteins. However, knowledge of the mechanisms by which this signal transduction system controls the cytoskeleton is still in its infancy. One story that is beginning to unfold is that SUMO may regulate the microtubule motor protein dynein by modification of its adaptor Lis1. In other instances, cytoskeletal elements can both bind to SUMO non-covalently and also be conjugated by it. The molecular mechanisms for many of these new functions are not yet clear, but are under active investigation. One emerging model links the function of MAP sumoylation to protein degradation through SUMO-targeted ubiquitin ligases, also known as STUbL enzymes. Other possible functions for cytoskeletal sumoylation are also discussed.
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Affiliation(s)
- Annabel Alonso
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwaterOklahoma
| | - Matt Greenlee
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwaterOklahoma
| | - Jessica Matts
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwaterOklahoma
| | - Jake Kline
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwaterOklahoma
| | - Kayla J. Davis
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwaterOklahoma
| | - Rita K. Miller
- Department of Biochemistry and Molecular BiologyOklahoma State UniversityStillwaterOklahoma
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Ehrlichia chaffeensis exploits host SUMOylation pathways to mediate effector-host interactions and promote intracellular survival. Infect Immun 2014; 82:4154-68. [PMID: 25047847 DOI: 10.1128/iai.01984-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Ehrlichia chaffeensis is an obligately intracellular Gram-negative bacterium that selectively infects mononuclear phagocytes. We recently reported that E. chaffeensis utilizes a type 1 secretion (T1S) system to export tandem repeat protein (TRP) effectors and demonstrated that these effectors interact with a functionally diverse array of host proteins. By way of these interactions, TRP effectors modulate host cell functions; however, the molecular basis of these interactions and their roles in ehrlichial pathobiology are not well defined. In this study, we describe the first bacterial protein posttranslational modification (PTM) by the small ubiquitin-like modifier (SUMO). The E. chaffeensis T1S effector TRP120 is conjugated to SUMO at a carboxy-terminal canonical consensus SUMO conjugation motif in vitro and in human cells. In human cells, TRP120 was selectively conjugated with SUMO2/3 isoforms. Disruption of TRP120 SUMOylation perturbed interactions with known host proteins, through predicted SUMO interaction motif-dependent and -independent mechanisms. E. chaffeensis infection did not result in dramatic changes in the global host SUMOylated protein profile, but a robust colocalization of predominately SUMO1 with ehrlichial inclusions was observed. Inhibiting the SUMO pathway with a small-molecule inhibitor had a significant impact on E. chaffeensis replication and recruitment of the TRP120-interacting protein polycomb group ring finger protein 5 (PCGF5) to the inclusion, indicating that the SUMO pathway is critical for intracellular survival. This study reveals the novel exploitation of the SUMO pathway by Ehrlichia, which facilitates effector-eukaryote interactions necessary to usurp the host and create a permissive intracellular niche.
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High glucose induces sumoylation of Smad4 via SUMO2/3 in mesangial cells. BIOMED RESEARCH INTERNATIONAL 2014; 2014:782625. [PMID: 24971350 PMCID: PMC4058256 DOI: 10.1155/2014/782625] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/01/2014] [Indexed: 11/29/2022]
Abstract
Recent studies have shown that sumoylation is a posttranslational modification involved in regulation of the transforming growth factor-β (TGF-β) signaling pathway, which plays a critical role in renal fibrosis in diabetic nephropathy (DN). However, the role of sumoylation in the regulation of TGF-β signaling in DN is still unclear. In the present study, we investigated the expression of SUMO (SUMO1 and SUMO2/3) and Smad4 and the interaction between SUMO and Smad4 in cultured rat mesangial cells induced by high glucose. We found that SUMO1 and SUMO2/3 expression was significantly increased in the high glucose groups compared to the normal group (P < 0.05). Smad4 and fibronectin (FN) levels were also increased in the high glucose groups in a dose-dependent manner. Coimmunoprecipitation and confocal laser scanning revealed that Smad4 interacted and colocalized with SUMO2/3, but not with SUMO1 in mesangial cells. Sumoylation (SUMO2/3) of Smad4 under high glucose condition was strongly enhanced compared to normal control (P < 0.05). These results suggest that high glucose may activate TGF-β/Smad signaling through sumoylation of Samd4 by SUMO2/3 in mesangial cells.
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16
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Shyu YC, Lee TL, Chen X, Hsu PH, Wen SC, Liaw YW, Lu CH, Hsu PY, Lu MJ, Hwang J, Tsai MD, Hwang MJ, Chen JR, Shen CKJ. Tight regulation of a timed nuclear import wave of EKLF by PKCθ and FOE during Pro-E to Baso-E transition. Dev Cell 2014; 28:409-22. [PMID: 24576425 DOI: 10.1016/j.devcel.2014.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 11/24/2013] [Accepted: 01/13/2014] [Indexed: 11/28/2022]
Abstract
Erythropoiesis is a highly regulated process during which BFU-E are differentiated into RBCs through CFU-E, Pro-E, PolyCh-E, OrthoCh-E, and reticulocyte stages. Uniquely, most erythroid-specific genes are activated during the Pro-E to Baso-E transition. We show that a wave of nuclear import of the erythroid-specific transcription factor EKLF occurs during the Pro-E to Baso-E transition. We further demonstrate that this wave results from a series of finely tuned events, including timed activation of PKCθ, phosphorylation of EKLF at S68 by P-PKCθ(S676), and sumoylation of EKLF at K74. The latter EKLF modifications modulate its interactions with a cytoplasmic ankyrin-repeat-protein FOE and importinβ1, respectively. The role of FOE in the control of EKLF nuclear import is further supported by analysis of the subcellular distribution patterns of EKLF in FOE-knockout mice. This study reveals the regulatory mechanisms of the nuclear import of EKLF, which may also be utilized in the nuclear import of other factors.
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Affiliation(s)
- Yu-Chiau Shyu
- Institute of Biopharmaceutical Sciences, National Yang-Ming University, Beitou, Taipei 112, Taiwan, ROC; Department of Education and Research, Taipei City Hospital, Da'an, Taipei 103, Taiwan, ROC; Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC.
| | - Tung-Liang Lee
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Xin Chen
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Pang-Hung Hsu
- The Genomics Research Center, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Shau-Ching Wen
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Yi-Wei Liaw
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Chi-Huan Lu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Po-Yen Hsu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Mu-Jie Lu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - JauLang Hwang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC
| | - Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Ming-Jing Hwang
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Jim-Ray Chen
- Department of Pathology, Keelung Chang Gung Memorial Hospital, Anle, Keelung 204, Taiwan, ROC; College of Medicine, Chang Gung University, Kwei-Shan, Taoyuan 259, Taiwan, ROC
| | - Che-Kun James Shen
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan 115, ROC.
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17
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Grunewald TGP, Willier S, Janik D, Unland R, Reiss C, da Costa OP, Buch T, Dirksen U, Richter GH, Neff F, Burdach S, Butt E. The Zyxin-related protein thyroid receptor interacting protein 6 (TRIP6) is overexpressed in Ewing's sarcoma and promotes migration, invasion and cell growth. Biol Cell 2013; 105:535-47. [DOI: 10.1111/boc.201300041] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 08/16/2013] [Indexed: 01/29/2023]
Affiliation(s)
- Thomas G. P. Grunewald
- Children's Cancer Research Center and Roman Herzog Comprehensive Cancer Center; Laboratory of Functional Genomics and Transplantation Biology; Klinikum rechts der Isar; Technische Universität München; Munich 80804 Germany
| | - Semjon Willier
- Institute for Clinical Biochemistry and Pathobiochemistry; University Clinic of Würzburg; Würzburg 97080 Germany
| | - Dirk Janik
- Institute of Pathology; Helmholtz Center Munich; Neuherberg 85764 Germany
| | - Rebekka Unland
- Department of Pediatric Hematology and Oncology; University Hospital Muenster; Westphalian Wilhelms University; Muenster 48149 Germany
| | - Cora Reiss
- Institute for Clinical Biochemistry and Pathobiochemistry; University Clinic of Würzburg; Würzburg 97080 Germany
- Center for Thrombosis and Hemostasis; University Medical Center Mainz; Mainz 55131 Germany
| | - Olivia Prazeres da Costa
- Institute for Medical Microbiology, Immunology, and Hygiene; Technische Universität München; Munich 81675 Germany
| | - Thorsten Buch
- Institute for Medical Microbiology, Immunology, and Hygiene; Technische Universität München; Munich 81675 Germany
| | - Uta Dirksen
- Department of Pediatric Hematology and Oncology; University Hospital Muenster; Westphalian Wilhelms University; Muenster 48149 Germany
| | - Günther H.S. Richter
- Children's Cancer Research Center and Roman Herzog Comprehensive Cancer Center; Laboratory of Functional Genomics and Transplantation Biology; Klinikum rechts der Isar; Technische Universität München; Munich 80804 Germany
| | - Frauke Neff
- Institute of Pathology; Helmholtz Center Munich; Neuherberg 85764 Germany
| | - Stefan Burdach
- Children's Cancer Research Center and Roman Herzog Comprehensive Cancer Center; Laboratory of Functional Genomics and Transplantation Biology; Klinikum rechts der Isar; Technische Universität München; Munich 80804 Germany
| | - Elke Butt
- Institute for Clinical Biochemistry and Pathobiochemistry; University Clinic of Würzburg; Würzburg 97080 Germany
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18
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Role of cysteine 288 in nucleophosmin cytoplasmic mutations: sensitization to toxicity induced by arsenic trioxide and bortezomib. Leukemia 2013; 27:1970-80. [DOI: 10.1038/leu.2013.222] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 06/27/2013] [Accepted: 07/04/2013] [Indexed: 11/08/2022]
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19
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Contribution of SUMO-interacting motifs and SUMOylation to the antiretroviral properties of TRIM5α. Virology 2012; 435:463-71. [PMID: 23084420 DOI: 10.1016/j.virol.2012.09.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 08/29/2012] [Accepted: 09/28/2012] [Indexed: 12/20/2022]
Abstract
Recent findings suggested that the SUMO-interacting motifs (SIMs) present in the human TRIM5α (TRIM5α(hu)) protein play an important role in the ability of TRIM5α(hu) to restrict N-MLV. Here we explored the role of SIMs in the ability of rhesus TRIM5α (TRIM5α(rh)) to restrict HIV-1, and found that TRIM5α(rh) SIM mutants IL376KK (SIM1mut) and VI405KK (SIM2mut) completely lost their ability to block HIV-1 infection. Interestingly, these mutants also lost the recently described property of TRIM5α(rh) to shuttle into the nucleus. Analysis of these variants revealed that they are unable to interact with the HIV-1 core, which might explain the reason that these variants are not active against HIV-1. Furthermore, NMR titration experiments to assay the binding between the PRYSPRY domain of TRIM5α(rh) and the small ubiquitin-like modifier 1(SUMO-1) revealed no interaction. In addition, we examined the role of SUMOylation in restriction, and find out that inhibition of SUMOylation by the adenoviral protein Gam1 did not alter the retroviral restriction ability of TRIM5α. Overall, our results do not support a role for SIMs or SUMOylation in the antiviral properties of TRIM5α.
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20
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Sohn SY, Hearing P. Adenovirus regulates sumoylation of Mre11-Rad50-Nbs1 components through a paralog-specific mechanism. J Virol 2012; 86:9656-65. [PMID: 22740413 PMCID: PMC3446602 DOI: 10.1128/jvi.01273-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 06/19/2012] [Indexed: 01/09/2023] Open
Abstract
The Mre11-Rad50-Nbs1 (MRN) complex plays a key role in the DNA damage response, presenting challenges for DNA viruses and retroviruses. To inactivate this complex, adenovirus (Ad) makes use of the E1B-55K and E4-open reading frame 6 (ORF6) proteins for ubiquitin (Ub)-mediated, proteasome-dependent degradation of MRN and the E4-ORF3 protein for relocalization and sequestration of MRN within infected-cell nuclei. Here, we report that Mre11 is modified by the Ub-related modifier SUMO-2 and Nbs1 is modified by both SUMO-1 and SUMO-2. We found that Mre11 and Nbs1 are sumoylated during Ad5 infection and that the E4-ORF3 protein is necessary and sufficient to induce SUMO conjugation. Relocalization of Mre11 and Nbs1 into E4-ORF3 nuclear tracks is required for this modification to occur. E4-ORF3-mediated SUMO-1 conjugation to Nbs1 and SUMO-2 conjugation to Mre11 and Nbs1 are transient during wild-type Ad type 5 (Ad5) infection. In contrast, SUMO-1 conjugation to Nbs1 is stable in cells infected with E1B-55K or E4-ORF6 mutant viruses, suggesting that Ad regulates paralog-specific desumoylation of Nbs1. Inhibition of viral DNA replication blocks deconjugation of SUMO-2 from Mre11 and Nbs1, indicating that a late-phase process is involved in Mre11 and Nbs1 desumoylation. Our results provide direct evidence of Mre11 and Nbs1 sumoylation induced by the Ad5 E4-ORF3 protein and an important example showing that modification of a single substrate by both SUMO-1 and SUMO-2 is regulated through distinct mechanisms. Our findings suggest how E4-ORF3-mediated relocalization of the MRN complex influences the cellular DNA damage response.
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Affiliation(s)
- Sook-Young Sohn
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
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21
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Baucher M, Pérez-Morga D, El Jaziri M. Insight into plant annexin function: from shoot to root signaling. PLANT SIGNALING & BEHAVIOR 2012; 7:524-8. [PMID: 22499168 PMCID: PMC3419045 DOI: 10.4161/psb.19647] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The multifunctionality of plant annexins and their importance for coordinating development and responses to biotic and abiotic environment have been largely reviewed. We recently described a tobacco annexin, named Ntann12, which is mainly localized in the nucleus of root cells when the plant is grown under light conditions. We also found that auxin and polar auxin transport are essential for Ntann12 accumulation in root cells. Under dark condition, Ntann12 is no longer detected in the root system. In the present addendum, light, regulating auxin signaling, is evidenced as an essential determinant for the synchronization of growth and development between the shoot and the root during light/dark cycle. A speculative model for Ntann12 is described and discussed with regards to relevant literature data.
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Affiliation(s)
- Marie Baucher
- Laboratoire de Biotechnologie Végétale, Université Libre de Bruxelles, Gosselies, Belgium.
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SUMO binding by the Epstein-Barr virus protein kinase BGLF4 is crucial for BGLF4 function. J Virol 2012; 86:5412-21. [PMID: 22398289 DOI: 10.1128/jvi.00314-12] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
An Epstein-Barr virus (EBV) protein microarray was used to screen for proteins binding noncovalently to the small ubiquitin-like modifier SUMO2. Among the 11 SUMO binding proteins identified was the conserved protein kinase BGLF4. The mutation of potential SUMO interaction motifs (SIMs) in BGLF4 identified N- and C-terminal SIMs. The mutation of both SIMs changed the intracellular localization of BGLF4 from nuclear to cytoplasmic, while BGLF4 mutated in the N-terminal SIM remained predominantly nuclear. The mutation of the C-terminal SIM yielded an intermediate phenotype with nuclear and cytoplasmic staining. The transfer of BGLF4 amino acids 342 to 359 to a nuclear green fluorescent protein (GFP)-tagged reporter protein led to the relocalization of the reporter to the cytoplasm. Thus, the C-terminal SIM lies adjacent to a nuclear export signal, and coordinated SUMO binding by the N- and C-terminal SIMs blocks export and allows the nuclear accumulation of BGLF4. The mutation of either SIM prevented SUMO binding in vitro. The ability of BGLF4 to abolish the SUMOylation of the EBV lytic cycle transactivator ZTA was dependent on both BGLF4 SUMO binding and BGLF4 kinase activity. The global profile of SUMOylated cell proteins was also suppressed by BGLF4 but not by the SIM or kinase-dead BGLF4 mutant. The effective BGLF4-mediated dispersion of promyelocytic leukemia (PML) bodies was dependent on SUMO binding. The SUMO binding function of BGLF4 was also required to induce the cellular DNA damage response and to enhance the production of extracellular virus during EBV lytic replication. Thus, SUMO binding by BGLF4 modulates BGLF4 function and affects the efficiency of lytic EBV replication.
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23
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Posttranslational modification of vesicular stomatitis virus glycoprotein, but not JNK inhibition, is the antiviral mechanism of SP600125. J Virol 2012; 86:4844-55. [PMID: 22345438 DOI: 10.1128/jvi.06649-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Vesicular stomatitis virus (VSV), a negative-sense single-stranded-RNA rhabdovirus, is an extremely promising oncolytic agent for cancer treatment. Since oncolytic virotherapy is moving closer to clinical application, potentially synergistic combinations of oncolytic viruses and molecularly targeted antitumor agents are becoming a meaningful strategy for cancer treatment. Mitogen-activated protein kinase (MAPK) inhibitors have been shown to impair liver cell proliferation and tumor development, suggesting their potential use as therapeutic agents for hepatocellular carcinoma (HCC). In this work, we show that the impairment of MAPK in vitro did not interfere with the oncolytic properties of VSV in HCC cell lines. Moreover, the administration of MAPK inhibitors did not restore the responsiveness of HCC cells to alpha/beta interferon (IFN-α/β). In contrast to previous reports, we show that JNK inhibition by the inhibitor SP600125 is not responsible for VSV attenuation in HCC cells and that this compound acts by causing a posttranslational modification of the viral glycoprotein.
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