DOCSLIB.ORG

Interactions Between Polyomavirus Large T Antigen and the Viral Replication Origin Dna: How and Why

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Interactions Between Polyomavirus Large T Antigen and the Viral Replication Origin Dna: How and Why INTERACTIONS BETWEEN POLYOMAVIRUS LARGE T ANTIGEN AND THE VIRAL REPLICATION ORIGIN DNA: HOW AND WHY by Yu-Cai Peng Department of Microbiology and Immunology McGill University, Montreal April, 1999 A thesis submitted to the Faculty of Craduate Studies and Re3earch in partial fulfullmeat of the requirements of the degree of doctor of philosophy @Yu-Cai Peng, 1999 National Library Biblioth ue nationale 1+1 of Canada du Cana7 a Acquisitions and Acquisitions et Bibliographie Srvices services bibliographiques 395 Wellmgton Street 395, nie Weliingîm Ottawa ON KIA ON4 OrtawaON K1AON4 Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive Licence ailowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfichelfilm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fkom it Ni la thèse ni des extraits substantiels may be printed or othenvise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. TABLE OF CONTENTS Page Tableofcontents................................................... I Abstract .......................................................... VI Resumé........................................................... VI11 Acknowledgements ................................................. X Claim of contribution to kaowledge ................................... XI Listoffigures ...................................................... XllI Guidelines regarding doctoral thesis ................................... XV CHAPTER 1. INTRODUCTION .................................... 1 1. Overview: Life cycle of polyomavirus and simian virus 40 ........... 1 II .A most multifunctional protein: large T antigen.................... 1. General properties........................................... A) Posttranslational rnodifcations ............................... B) Nuclear locaiization ........................................ C) Oligomerization ........................................... 2 . Functions in viral DNA replication ............................. A) Originsfor viral DNA repiicatbn ............................. B) Large T antigen and viral DNA replication ...................... C) Regulation of DNA replication by phosphorylation of large T antigen . D) Replication factors interacting with large T antigen ............... i) Replication protein A .................................... ii) DNA polymerase a: primase .............................. iii) Topoisomerase I ........................................ E) Zhc-f»>gerand Dnd domains on large T antigen ................. i) Zinc-jnger domain ...................................... ii) Dnal domain .......................................... 3. Functionfi in regulation of transcription ........................ A) Regulation of viral gene expression ........................... B) Interactions between large T antigen and ~ranscriptionfactors ...... 32 4 . Functions in immortalization and transformation of infected cells ... 34 A) TranF/orming activiy of T antigens ............................ 35 B) Cellular targetsfor large T antigen implicated in its transforming uctiviîy ....................................... 38 i) p ................................................... 38 ii) pRb/p107/p130 ......................................... 39 iii) p300/CBP ............................................. 42 III .DNA Binding by large T antigens ............................... 1. Origin specific DNA binding ................................. 2 . Nonorigin DNA binding ..................................... 3. DNA-binding domains on large T antigen ...................... 4 . Formation of large T antigen hexamers in the core origin ......... 5. DNA dbtortioiis associated with large T antigen binding andoligomeriution ......................................... 6. Conditions that affect DNA binding by large T antigen ........... A) nucleotides ............................................... B) phosphorylation ........................................... C) pH ...................................................... IV . Production of large T antigens for in vitro analysis ................. 67 1. Expression with an adenovirus vector system ................... 67 2 . Expression in E. coli ........................................ 69 3 . Expression with a baculovirus system .......................... 70 4 . Expression in yeast: Pichia pastoris system ...................... 71 CHAPTER 2 . MATERIALS AND METHODS ........................ 75 1. Ce11 cultures .................................................. 75 1. Strains .................................................... 75 2. Media and growth conditions ................................. 76 3. Yeast and bacterial transformation ............................ 77 4. Screening for yeast transformants expressing large T antigen ...... 77 II. Nucleicacids ................................................. 78 1. DNA extraction and enzymatic manipulations ................... 78 2 . PCR ampliIication .......................................... 79 3. PIasmid constructs .......................................... 80 III. Protein analysis .............................................. 83 1. Western blottiag and silver staining ........................... 83 2 . Immunoaffinity column prepamtion ........................... 83 3. Expression and purification of polyomavirus large T antigen ...... 84 IV. Assays for protein-DNA interactions ............................. 87 1. Filter binding assay ......................................... 87 2. DNase 1 footprinting analysis ................................. 88 3. Gel electrophoresis mobility shift assay ........................ 89 1. DNA immunoprecipitation assay .............................. 89 5 . Glycerol gradient centrifugation .............................. 90 6. Duplex DNA fragment unwinding assay ........................ 91 CHAPTER 3. Production of active polyomavirus large T antigen inycastPlcliiapmtoris ................................. Absfract ..................................................... Introduction .................................................. Results ...................................................... lntegration of polyomavhs large T antigen gene into yeast Pichia pmris and expression of the large T antigen .............. Specific DNA-binding and purification of the yeast-derived large T antigen ............................................ Purified large T antigen unwinds duplex DNA fragment ........... Discussion .................................................... III CHAPTER 4. Polyomavinis large T mtigen bhds cooperatively to its multiple binding sites in the viral ongin of DNA repücation .. Connecting text ............................................... Introduction ...................................~~...~.~.~.~~.~ Results ....................................................... Specific origin-binding activity of polyomavirus large T antigen is enhanced at pH 7 and below ................................ Large T antigen-DNA complexes are stable at pH 6 to 7 but are unstable at pH 7.6 .......................................... ATP does not affect DNA binding at pH 7 or below but stabilizes a fraction of large T antigen-origin DNA complexes at high pH ...... Stabilization of complexes by ATP depends on the presence of site 112 Binding of large T antigen to origin DNA fragments containing one or more adjacent binding sites ................................ Binding of large T antigen to DNA targets containing mutated binding sites .............................................. DNase 1 footprinting of mutant DNAs in the presence of large T antigen .................................................. ATP specifically enhances protection against DNase 1 digestion of the central 1O to 12 bp of site 112 .............................. Discussion .................................................... CHAPTER 5. Enhanced binding to origin DNA at low pH enables easy detection of polyomavirus large T antigen by gel mobility shift assay of unfucd complexes ......................... 145 Connecting text ............................................... 146 Abstract ..................................................... 147 Introduction .................................................. 148 Results ...................................,.................. 150 Gel mobility shift assay of large T antigen-DNA complexes at pH 6: sensitivity and specificity ............................. 150 Application of gel mobility shift assay to crude lysates of cells expressing large T antigen ................................... Glycerol gradient analysis of large T antigen-DNA complexes ...... Influence of binding sites on gel retardation ..................... Discussion .................................................... CHAPTER 6. SUMMARY AND CONCLUSIONS ..................... 1. Expression of large T antigen in Pichia pasioris .................. II . pH effect on origin DNA binding by large T antigen .............. III . Applications of the pH effect on large T antigen DNA binding ..... IV . ATP effect on ongin DNA binding by large
Load more

Recommended publications
  • Structure and Expression of Class II Defective Herpes Simplex Virus
    JOURNAL OF VIROLOGY, Aug. 1982, p. 574-593 Vol. 43, No. 2 0022-538X/82/080574-20$02.00/0 Structure and Expression of Class II Defective Herpes Simplex Virus Genomes Encoding Infected Cell Polypeptide Number 8 HILLA LOCKER,1t NIZA FRENKEL,l* AND IAN HALLIBURTON2 Department ofBiology, The University of Chicago, Chicago, Illinois 60637,1 and Department of Microbiology, University ofLeeds, Leeds, England' Received 12 February 1982/Accepted 13 May 1982 Defective genomes present in serially passaged virus stocks derived from the tsLB2 mutant of herpes simplex virus type 1 were found to consist of repeat units in which sequences from the UL region, within map coordinates 0.356 and 0.429 of standard herpes simplex virus DNA, were covalently linked to sequences from the end of the S component. The major defective genome species consisted of repeat units which were 4.9 x 106 in molecular weight and contained a specific deletion within the UL segment. These tsLB2 defective genomes were stable through more than 35 sequential virus passages. The ratios of defective virus genomes to helper virus genomes present in different passages fluctuated in synchrony with the capacity of the passages to interfere with standard virus replication. Cells infected with passages enriched for defective genomes overpro- duced the infected cell polypeptide number 8, which had previously been mapped within the UL sequences present in the tsLB2 defective genomes. In contrast, the synthesis of most other infected cell polypeptides was delayed and reduced. The abundant synthesis of infected cell polypeptide number 8 followed the , regula- tory pattern, as evident from kinetic studies and from experiments in which cycloheximide, canavanine, and phosphonoacetate were used.
    [Show full text]
  • Enhanced Expression of Vascular Endothelial Growth Factor (VEGF) Plays a Critical Role in the Tumor Progression Potential Induced by Simian Virus 40 Large T Antigen
    Oncogene (2002) 21, 2896 ± 2900 ã 2002 Nature Publishing Group All rights reserved 0950 ± 9232/02 $25.00 www.nature.com/onc Enhanced expression of vascular endothelial growth factor (VEGF) plays a critical role in the tumor progression potential induced by simian virus 40 large T antigen Alfonso Catalano1, Mario Romano*,2, Stefano Martinotti3 and Antonio Procopio*,1 1Institute of Experimental Pathology, University of Ancona, Faculty of Medicine, Via Ranieri, 60131 Ancona, Italy; 2Department of Human Pathology, University of Messina, 98125 Messina, Italy; 3Department of Oncology and Neuroscience, `G. D'Annunzio' University, Chieti, Italy Vascular endothelial growth factor (VEGF), an impor- disorders, including mesotheliomas (Kumar-Singh et tant angiogenic factor, regulates cell proliferation, al., 1999). Among these, VEGF, whose crucial role in dierentiation, and apoptosis through activation of its tumor angiogenesis is well established (Hanahan and tyrosine-kinase receptors, such as Flt-1 and Flk-1/Kdr. Folkman., 1996), acts also as a potent mitogen and Human malignant mesothelioma cells (HMC), which survival factor for human malignant mesothelioma have wild-type p53, express VEGF and exhibit cell cells (HMC). In fact, VEGF regulates HMC prolifera- growth increased by VEGF. Here, we demonstrate that tion through its tyrosine-kinase receptors activation early transforming proteins of simian virus (SV) 40, large (i.e. Flt-1 and KDR/¯k-1) (Strizzi et al., 2001). In tumor antigen (Tag) and small tumor antigen (tag), addition, VEGF is the main eector of 5-lipoxygenase which have been associated with mesotheliomas, en- action on HMC survival (Romano et al., 2001). Thus, hanced HMC proliferation by inducing VEGF expres- VEGF plays a key role by regulating multiple sion.
    [Show full text]
  • Oncogenes of DNA Tumor Viruses1
    [CANCER RESEARCH 48. 493-496. February I. 1988] Perspectives in Cancer Research Oncogenes of DNA Tumor Viruses1 Arnold J. Levine Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544 Experiments carried out over the past 10-12 years have the cellular oncogenes. It will attempt to identify where more created a field or approach which may properly be termed the information is required or contradictions appear in the devel molecular basis of cancer. One of its major accomplishments oping concepts. Finally, this communication will examine ex has been the identification and understanding of some of the amples of cooperation between oncogenes and other gene prod functions of a group of cancer-causing genes, the oncogenes. ucts which modify the mode of action of the former. If we are The major path to the oncogenes came from the study of cancer- on the right track, then general principles may well emerge. causing viruses. The oncogenes have been recognized and stud Tumor formation in animals or transformation in cell culture ied by two separate but related groups of virologists focusing has been demonstrated with many different DNA-containing upon either the DNA (1) or RNA (2) tumor viruses (they even viruses (1). In most cases it has been possible to identify one or have separate meetings now that these fields have grown so a few viral genes and their products that are responsible for large). From their studies it has become clear that the oncogenes transformation or, in some cases, tumorigenesis. A list of these of each virus type have very different origins.
    [Show full text]
  • Tätigkeitsbericht 2007/2008
    Tätigkeitsbericht 2007/2008 8 200 / 7 0 20 Tätigkeitsbericht Stiftung bürgerlichen Rechts Martinistraße 52 · 20251 Hamburg Tel.: +49 (0) 40 480 51-0 · Fax: +49 (0) 40 480 51-103 [email protected] · www.hpi-hamburg.de Impressum Verantwortlich Prof. Dr. Thomas Dobner für den Inhalt Dr. Heinrich Hohenberg Redaktion Dr. Angela Homfeld Dr. Nicole Nolting Grafik & Layout AlsterWerk MedienService GmbH Hamburg Druck Hartung Druck + Medien GmbH Hamburg Titelbild Neu gestaltete Fassade des Seuchenlaborgebäudes Tätigkeitsbericht 2007/2008 Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg Martinistraße 52 · 20251 Hamburg Postfach 201652 · 20206 Hamburg Telefon: +49-40/4 80 51-0 Telefax: +49-40/4 80 51-103 E-Mail: [email protected] Internet: www.hpi-hamburg.de Das Heinrich-Pette-Institut ist Mitglied der Leibniz-Gemeinschaft (WGL) Internet: www.wgl.de Inhaltsverzeichnis Allgemeiner Überblick Vorwort ................................................................................................... 1 Die Struktur des Heinrich-Pette-Instituts .............................................. 2 Modernisierung des HPI erfolgreich abgeschlossen ............................ 4 60 Jahre HPI .............................................................................................. 5 Offen für den Dialog .............................................................................. 6 Preisverleihungen und Ehrungen .......................................................... 8 Personelle Veränderungen in
    [Show full text]
  • THE ROLE of the HERPES SIMPLEX VIRUS TYPE 1 UL28 PROTEIN in TERMINASE COMPLEX ASSEMBLY and FUNCTION by Jason Don Heming Bachelor
    THE ROLE OF THE HERPES SIMPLEX VIRUS TYPE 1 UL28 PROTEIN IN TERMINASE COMPLEX ASSEMBLY AND FUNCTION by Jason Don Heming Bachelor of Science, Clarion University of Pennsylvania, 2004 Submitted to the Graduate Faculty of the School of Medicine in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Pittsburgh 2013 UNIVERSITY OF PITTSBURGH SCHOOL OF MEDICINE This dissertation was presented by Jason Don Heming It was defended on April 18, 2013 and approved by Michael Cascio, Associate Professor, Bayer School of Natural and Environmental Sciences James Conway, Associate Professor, Department of Structural Biology Neal DeLuca, Professor, Department of Microbiology and Molecular Genetics Saleem Khan, Professor, Department of Microbiology and Molecular Genetics Dissertation Advisor: Fred Homa, Associate Professor, Department of Microbiology and Molecular Genetics ii Copyright © by Jason Don Heming 2013 iii THE ROLE OF THE HERPES SIMPLEX VIRUS TYPE 1 UL28 PROTEIN IN TERMINASE COMPLEX ASSEMBLY AND FUNCTION Jason Don Heming, PhD University of Pittsburgh, 2013 Herpes simplex virus type I (HSV-1) is the causative agent of several pathologies ranging in severity from the common cold sore to life-threatening encephalitic infection. During productive lytic infection, over 80 viral proteins are expressed in a highly regulated manner, resulting in the replication of viral genomes and assembly of progeny virions. Cleavage and packaging of replicated, concatemeric viral DNA into newly assembled capsids is critical to virus proliferation and requires seven viral genes: UL6, UL15, UL17, UL25, UL28, UL32, and UL33. Analogy with the well-characterized cleavage and packaging systems of double-stranded DNA bacteriophage suggests that HSV-1 encodes for a viral terminase complex to perform these essential functions, and several studies have indicated that this complex consists of the viral UL15, UL28, and UL33 proteins.
    [Show full text]
  • Inhibition of HIV-1 by an Anti-Integrase Single-Chain Variable
    Gene Therapy (1999) 6, 660–666 1999 Stockton Press All rights reserved 0969-7128/99 $12.00 http://www.stockton-press.co.uk/gt Inhibition of HIV-1 by an anti-integrase single-chain variable fragment (SFv): delivery by SV40 provides durable protection against HIV-1 and does not require selection M BouHamdan1, L-X Duan1, RJ Pomerantz1 and DS Strayer1,2 1The Dorrance H Hamilton Laboratories, Center for Human Virology, Division of Infectious Diseases, Department of Medicine; and 2Department of Pathology, Anatomy and Cell Biology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA Human immunodeficiency virus type I (HIV-1) encodes the SFv-IN was confirmed by Western blotting and several proteins that are packaged into virus particles. Inte- immunofluorescence staining, which showed that Ͼ90% of grase (IN) is an essential retroviral enzyme, which has SupT1 T-lymphocytic cells treated with SV(Aw) expressed been a target for developing agents to inhibit virus repli- the SFv-IN protein without selection. When challenged, cation. In previous studies, we showed that intracellular HIV-1 replication, as measured by HIV-1 p24 antigen expression of single-chain variable antibody fragments expression and syncytium formation, was potently inhibited (SFvs) that bind IN, delivered via retroviral expression vec- in cells expressing SV40-delivered SFv-IN. Levels of inhi- tors, provided resistance to productive HIV-1 infection in bition of HIV-1 infection achieved using this approach were T-lymphocytic cells. In the current studies, we evaluated comparable to those achieved using murine leukemia virus simian-virus 40 (SV40) as a delivery vehicle for anti-IN (MLV) as a transduction vector, the major difference being therapy of HIV-1 infection.
    [Show full text]
  • Herpes Simplex Virus 1 ICP8 Mutant Lacking Annealing Activity Is Deficient for Viral DNA Replication
    Herpes simplex virus 1 ICP8 mutant lacking annealing activity is deficient for viral DNA replication Savithri Weerasooriyaa,1, Katherine A. DiScipioa,b,1, Anthar S. Darwisha,b, Ping Baia, and Sandra K. Wellera,2 aDepartment of Molecular Biology and Biophysics, University of Connecticut School of Medicine, Farmington, CT 06030; and bMolecular Biology and Biochemistry Graduate Program, University of Connecticut School of Medicine, Farmington, CT 06030 Edited by Jack D. Griffith, University of North Carolina, Chapel Hill, NC, and approved December 4, 2018 (received for review October 13, 2018) Most DNA viruses that use recombination-dependent mechanisms culating in patient populations (18–22). Additionally, it has long to replicate their DNA encode a single-strand annealing protein been recognized that viral replication intermediates are com- (SSAP). The herpes simplex virus (HSV) single-strand DNA binding posed of complex X- and Y-branched structures as evidenced by protein (SSB), ICP8, is the central player in all stages of DNA electron microscopy (10, 16) and pulsed-field gel electrophoresis replication. ICP8 is a classical replicative SSB and interacts physi- (15, 23, 24). ′ ′ cally and/or functionally with the other viral replication proteins. The HSV exo/SSAP, composed of a 5 -to-3 exonuclease Additionally, ICP8 can promote efficient annealing of complemen- (UL12) and an SSAP (ICP8), is capable of promoting strand ex- tary ssDNA and is thus considered to be a member of the SSAP change in vitro (25, 26). More recently, we have shown that HSV infection stimulates single-strand annealing (27), and ICP8 has family. The role of annealing during HSV infection has been been reported to promote recombineering in transfected cells difficult to assess in part, because it has not been possible to (28).
    [Show full text]
  • Type of the Paper (Article
    Viruses 2018 – Breakthroughs in Viral Replication Faculty of Biology University of Barcelona Spain 7 – 9 February 2018 Conference Chair Eric O. Freed Conference Co-Chair Albert Bosch Organised by Conference Secretariat Antonio Peteira Man Luo George Andrianou Nikoleta Kiapidou Kristjana Xhuxhi Pablo Velázquez Lucia Russo Sara Martínez Lynn Huang Sarai Rodríguez Viruses 2018 – Breakthroughs in Viral Replication 1 CONTENTS Abridged Programme 5 Conference Programme 6 Welcome 13 General Information 15 Abstracts – Session 1 25 General Topics in Virology Abstracts – Session 2 45 Structural Virology Abstracts – Session 3 67 Virus Replication Compartments Abstracts – Session 4 89 Replication and Pathogenesis of RNA viruses Abstracts – Session 5 105 Genome Packaging and Replication/Assembly Abstracts – Session 6 127 Antiviral Innate Immunity and Viral Pathogenesis Abstracts – Poster Exhibition 147 List of Participants 297 Viruses 2018 – Breakthroughs in Viral Replication 3 Viruses 2018 – Breakthroughs in Viral Replication 7 – 9 February 2018, Barcelona, Spain Wednesday Thursday Friday 7 February 2018 8 February 2018 9 February 2018 S3. Virus S5. Genome Check-in Replication Packaging and Compartments Replication/Assembly Opening Ceremony S1. General Topics in Virology Morning Coffee Break S1. General Topics S3. Virus S5. Genome in Virology Replication Packaging and Compartments Replication/Assembly Lunch S2. Structural S4. Replication and S6. Antiviral Innate Virology Pathogenesis of Immunity and Viral RNA Viruses Pathogenesis Coffee Break Apéro and Poster Coffee Break Session S2. Structural S6. Antiviral Innate Virology Immunity and Viral Afternoon Conference Group Pathogenesis Photograph Closing Remarks Conference Dinner Wednesday 7 February 2018: 08:00 - 12:30 / 14:00 - 18:00 / Conference Dinner: 20:30 Thursday 8 February 2018: 08:30 - 12:30 / 14:00 - 18:30 Friday 9 February 2018: 08:30 - 12:30 / 14:00 - 18:15 Viruses 2018 – Breakthroughs in Viral Replication 5 Conference Programme Wednesday 7 February 08:00 – 08:45 Check-in 08:45 – 09:00 Opening Ceremony by Eric O.
    [Show full text]
  • A Polyoma Mutant That Encodessmall T Antigen but Not Middle T Antigen
    MOLECULAR AND CELLULAR BIOLOGY, Dec. 1984, p. 2774-2783 Vol. 4, No. 12 0270-7306/84/122774-10$02.00/0 Copyright © 1984, American Society for Microbiology A Polyoma Mutant That Encodes Small T Antigen But Not Middle T Antigen Demonstrates Uncoupling of Cell Surface and Cytoskeletal Changes Associated with Cell Transformation T. JAKE LIANG, GORDON G. CARMICHAEL,t AND THOMAS L. BENJAMIN* Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115 Received 2 July 1984/Accepted 31 August 1984 The hr-t gene of polyoma virus encodes both the small and middle T (tumor) antigens and exerts pleiotropic effects on cells. By mutating the 3' splice site for middle T mRNA, we have constructed a virus mutant, Py8O8A, which fails to express middle T but encodes normal small and large T proteins. The mutant failed to induce morphological transformation or growth in soft agar, but did stimulate postconfluent growth of normal cells. Cells infected by Py8O8A became fully agglutinable by lectins while retaining normal actin cable architecture and normal levels of extracellular fibronectin. These properties of Py8O8A demonstrated the separability of structural changes at the cell surface from those in the cytoskeleton and extracellular matrix, parameters which have heretofore been linked in the action of the hr-t and other viral oncogenes. The early region of polyoma encodes three proteins de- substitution of phenylalanine for tyrosine at position 315 in tected as tumor (T) antigens. These polypeptides of 100,000 middle T has been made and studied in two laboratories, daltons (100K; large T), 56K (middle T), and 22K (small T) with different results.
    [Show full text]
  • SV40 Large T Antigen Targets Multiple Cellular Pathways to Elicit Cellular Transformation
    Oncogene (2005) 24, 7729–7745 & 2005 Nature Publishing Group All rights reserved 0950-9232/05 $30.00 www.nature.com/onc SV40 large T antigen targets multiple cellular pathways to elicit cellular transformation Deepika Ahuja1,2, M Teresa Sa´ enz-Robles1,2 and James M Pipas*,1 1Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA DNA tumor viruses such as simian virus 40 (SV40) three proteins that are structural components of the express dominant acting oncoproteins that exert their virion (VP1, VP2, VP3) and two nonstructural proteins effects by associating with key cellular targets and termed large T antigen (T antigen) and small T antigen altering the signaling pathways they govern. Thus, tumor (t antigen). In addition, some members of the Polyoma- viruses have proved to be invaluable aids in identifying viridae encode additional proteins that are virus specific proteins that participate in tumorigenesis, and in under- or are encoded by a subset of viruses in the family. For standing the molecular basis for the transformed pheno- example, SV40 encodes three such proteins: agnopro- type. The roles played by the SV40-encoded 708 amino- tein, 17K T, and small leader protein. The genomes of acid large T antigen (T antigen), and 174 amino acid small all polyomaviruses can be divided into three elements: T antigen (t antigen), in transformation have been an early coding unit, a late coding unit, and a regulatory examined extensively. These studies have firmly estab- region (Figure 1). In a productive infection, expression lished that large T antigen’s inhibition of the p53 and Rb- of the early coding unit is effected by the cellular family of tumor suppressors and small T antigen’s action transcription apparatus and results in expression of the on the pp2A phosphatase, are important for SV40-induced large, small and 17K T antigens.
    [Show full text]
  • Hepatitis B Virus X Protein Inhibits P53 Sequence-Specific DNA Binding
    Proc. Nati. Acad. Sci. USA Vol. 91, pp. 2230-2234, March 1994 Medical Sciences Hepatitis B virus X protein inhibits p53 sequence-specific DNA binding, transcriptional activity, and association with transcription factor ERCC3 XIN WEI WANG*, KATHLEEN FORRESTER*, HEIDI YEH*, MARK A. FEITELSONt, JEN-REN GUI, AND CURTIS C. HARRIS*§ *Laboratory of Human Carcinogenesis, Division of Cancer Etiology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892; tDepartment of Pathology and Cell Biology, Jefferson Medical College, Philadelphia, PA 19107; and tDepartment of Molecular Biology and Biochemistry, Shanghai Cancer Institute, Shanghai, People's Republic of China. Communicated by Bert Vogelstein, December 27, 1993 (receivedfor review December 9, 1993) ABSTRACT Chronic active hepatitis caused by infection about the role of HBX in HCC development. In this report, with hepatitis B virus, a DNA virus, is a major risk factor for we present results consistent with the hypothesis that HBX human hepatocellular carcinoma. Since the oncogenicity of binds to p53 and abrogates its normal cellular functions. several DNA viruses is dependent on the interaction of their viral oncoproteins with cellular tumor-suppressor gene prod- MATERIAL AND METHODS ucts, we investigated the interaction between hepatitis B virus X protein (HBX) and human wild-type p53 protein. HBX Plasmids. Plasmid constructs encoding GST-p53-WT, con- complexes with the wild-type p53 protein and inhibits its taining glutathione S-transferase (GST) fused to human wild- sequence-specific DNA binding in vitro. HBX expresslin also type p53, and GST-p53-135Y, containing GST fused to the inhibits p53-mediated transcrptional activation in vivo and the mutant p53 containing a His -* Tyr mutation at codon 135, in vitro asoition of p53 and ERCC3, a general transcription were provided by Jon Huibregtse (National Cancer Institute) factor involved in nucleotide excision repair.
    [Show full text]
  • P53 and the Viral Connection: Back Into the Future ‡
    cancers Review p53 and the Viral Connection: Back into the Future ‡ Ronit Aloni-Grinstein 1,2,†, Meital Charni-Natan 1,†, Hilla Solomon 1 and Varda Rotter 1,* 1 Department of Molecular Cell Biology, Weizmann Institute of Science, 76100 Rehovot, Israel; [email protected] (R.A.-G.); [email protected] (M.C.-N.); [email protected] (H.S.) 2 Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Box 19, 74100 Ness-Ziona, Israel * Correspondence: [email protected]; Tel.: +972-8-9344501; Fax: +972-8-9342398 † These authors contributed equally to this work. ‡ This review is dedicated to the 25th memorial year of Prof. Yosef Aloni of the Weizmann Institute of Science, for his seminal and important pioneering research in the field of molecular biology of the SV40 virus. Received: 15 May 2018; Accepted: 1 June 2018; Published: 4 June 2018 Abstract: The discovery of the tumor suppressor p53, through its interactions with proteins of tumor-promoting viruses, paved the way to the understanding of p53 roles in tumor virology. Over the years, accumulating data suggest that WTp53 is involved in the viral life cycle of non-tumor-promoting viruses as well. These include the influenza virus, smallpox and vaccinia viruses, the Zika virus, West Nile virus, Japanese encephalitis virus, Human Immunodeficiency Virus Type 1, Human herpes simplex virus-1, and more. Viruses have learned to manipulate WTp53 through different strategies to improve their replication and spreading in a stage-specific, bidirectional way. While some viruses require active WTp53 for efficient viral replication, others require reduction/inhibition of WTp53 activity.
    [Show full text]