1
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Schildgen O, Gräper S, Blümel J, Külshammer M, Matz B. Temperature-sensitive origin-binding protein as a tool for investigations of herpes simplex virus activities in vivo. J Gen Virol 2018; 100:105-117. [PMID: 30520714 DOI: 10.1099/jgv.0.001184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
While it is fairly clear that herpes simplex virus (HSV) DNA replication requires at least seven virus-encoded proteins in concert with various host cell factors, the mode of this process in infected cells is still poorly understood. Using HSV-1 mutants bearing temperature-sensitive (ts) lesions in the UL9 gene, we previously found that the origin-binding protein (OBP), a product of the UL9 gene, is only needed in the first 6 hours post-infection. As this finding was just a simple support for the hypothesis of a biphasic replication mode, we became convinced through these earlier studies that the mutants tsR and tsS might represent suitable tools for more accurate investigations in vivo. However, prior to engaging in highly sophisticated research projects, knowledge of the biochemical features of the mutated versions of OBP appeared to be essential. The results of our present study demonstrate that (i) tsR is most appropriate for cell biological studies, where only immediate early and early HSV gene products are being expressed without the concomital viral DNA replication, and (ii) tsS is a prime candidate for the analysis of HSV DNA replication processes because of its reversibly thermosensitive OBP-ATPase, which allows one to switch on the initiation of DNA synthesis precisely.
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Affiliation(s)
- Oliver Schildgen
- †Present address: Kliniken der Stadt Köln gGmbH, Krankenhaus Merheim, Klinikum der Privaten Universität Witten/Herdecke, Institut für Pathologie, Ostmerheimer Strasse 200, D-51109 Köln, Germany.,Institute of Virology, University of Bonn, Bonn, Germany
| | - Sascha Gräper
- Institute of Virology, University of Bonn, Bonn, Germany.,‡Present address: Sanofi-Aventis, Industriepark Hoechst, Bldg. D681, D-65926 Frankfurt am Main, Germany
| | - Johannes Blümel
- Institute of Virology, University of Bonn, Bonn, Germany.,§Present address: Paul-Ehrlich-Institu, Paul-Ehrlich-Strasse 51-59, D-63225 Langen, Germany
| | | | - Bertfried Matz
- Institute of Virology, University of Bonn, Bonn, Germany
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2
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Moiseeva ED, Bazhulina NP, Gursky YG, Grokhovsky SL, Surovaya AN, Gursky GV. Targeting Holliday junctions by origin DNA-binding protein of herpes simplex virus type 1. J Biomol Struct Dyn 2016; 35:704-723. [PMID: 26987269 DOI: 10.1080/07391102.2016.1161561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In the present paper, the interactions of the origin binding protein (OBP) of herpes simplex virus type 1 (HSV1) with synthetic four-way Holliday junctions (HJs) were studied using electrophoresis mobility shift assay and the FRET method and compared with the interactions of the protein with duplex and single-stranded DNAs. It has been found that OBP exhibits a strong preference for binding to four-way and three-way DNA junctions and possesses much lower affinities to duplex and single-stranded DNAs. The protein forms three types of complexes with HJs. It forms complexes I and II which are reminiscent of the tetramer and octamer complexes with four-way junction of HJ-specific protein RuvA of Escherichia coli. The binding approaches saturation level when two OBP dimers are bound per junction. In the presence of Mg2+ ions (≥2 mM) OBP also interacts with HJ in the stacked arm form (complex III). In the presence of 5 mM ATP and 10 mM Mg2+ ions OBP catalyzes processing of the HJ in which one of the annealed oligonucleotides has a 3'-terminal tail containing 20 unpaired thymine residues. The observed preference of OBP for binding to the four-way DNA junctions provides a basis for suggestion that OBP induces large DNA structural changes upon binding to Box I and Box II sites in OriS. These changes involve the bending and partial melting of the DNA at A+T-rich spacer and also include the formation of HJ containing Box I and Box II inverted repeats and flanking DNA sequences.
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Affiliation(s)
- E D Moiseeva
- a Engelhardt Institute of Molecular Biology , Russian Academy of Sciences , ul. Vavilova 32, 119991 Moscow , Russia
| | - N P Bazhulina
- a Engelhardt Institute of Molecular Biology , Russian Academy of Sciences , ul. Vavilova 32, 119991 Moscow , Russia
| | - Y G Gursky
- b Russian Cardiology Research-and-Production Complex , 3ya Cherepkovskaya ul. 15a, 121552 Moscow , Russia
| | - S L Grokhovsky
- a Engelhardt Institute of Molecular Biology , Russian Academy of Sciences , ul. Vavilova 32, 119991 Moscow , Russia
| | - A N Surovaya
- a Engelhardt Institute of Molecular Biology , Russian Academy of Sciences , ul. Vavilova 32, 119991 Moscow , Russia
| | - G V Gursky
- a Engelhardt Institute of Molecular Biology , Russian Academy of Sciences , ul. Vavilova 32, 119991 Moscow , Russia
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3
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Peng C, Chen J, Tang W, Liu C, Chen X. Kaposi's sarcoma-associated herpesvirus ORF6 gene is essential in viral lytic replication. PLoS One 2014; 9:e99542. [PMID: 24911362 PMCID: PMC4050029 DOI: 10.1371/journal.pone.0099542] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 05/15/2014] [Indexed: 11/25/2022] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV) is associated with Kaposis's sarcoma (KS), primary effusion lymphoma and multicentric Castleman's disease. KSHV encodes at least 8 open reading frames (ORFs) that play important roles in its lytic DNA replication. Among which, ORF6 of KSHV encodes an ssDNA binding protein that has been proved to participate in origin-dependent DNA replication in transient assays. To define further the function of ORF6 in the virus life cycle, we constructed a recombinant virus genome with a large deletion within the ORF6 locus by using a bacterial artificial chromosome (BAC) system. Stable 293T cells carrying the BAC36 (wild type) and BACΔ6 genomes were generated. When monolayers of 293T-BAC36 and 293T-BACΔ6 cells were induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate, infectious virus was detected from the 293T-BAC36 cell supernatants only and not from the 293T- BACΔ6 cell supernatants. DNA synthesis was defective in 293T-BACΔ6 cells. Expression of ORF6 in trans in BACΔ6-containing cells was able to rescue both defects. Our results provide genetic evidence that ORF6 is essential for KSHV lytic replication. The stable 293T cells carrying the BAC36 and BACΔ6 genomes could be used as tools to investigate the detailed functions of ORF6 in the lytic replication of KSHV.
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Affiliation(s)
- Can Peng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, P.R. China
| | - Jungang Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, P.R. China
| | - Wei Tang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, P.R. China
| | - Chunlan Liu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, P.R. China
| | - Xulin Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, P.R. China
- * E-mail:
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4
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Bazhulina NP, Surovaya AN, Gursky YG, Andronova VL, Moiseeva ED, Nikitin CACM, Golovkin MV, Galegov GА, Grokhovsky SL, Gursky GV. Complex of the herpes simplex virus type 1 origin binding protein UL9 with DNA as a platform for the design of a new type of antiviral drugs. J Biomol Struct Dyn 2013; 32:1456-73. [PMID: 23879454 PMCID: PMC4066892 DOI: 10.1080/07391102.2013.820110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The herpes simplex virus type 1 origin-binding protein, OBP, is a DNA helicase encoded by the UL9 gene. The protein binds in a sequence-specific manner to the viral origins of replication, two OriS sites and one OriL site. In order to search for efficient inhibitors of the OBP activity, we have obtained a recombinant origin-binding protein expressed in Escherichia coli cells. The UL9 gene has been amplified by PCR and inserted into a modified plasmid pET14 between NdeI and KpnI sites. The recombinant protein binds to Box I and Box II sequences and possesses helicase and ATPase activities. In the presence of ATP and viral protein ICP8 (single-strand DNA-binding protein), the initiator protein induces unwinding of the minimal OriS duplex (≈80 bp). The protein also binds to a single-stranded DNA (OriS*) containing a stable Box I-Box III hairpin and an unstable AT-rich hairpin at the 3'-end. In the present work, new minor groove binding ligands have been synthesized which are capable to inhibit the development of virus-induced cytopathic effect in cultured Vero cells. Studies on binding of these compounds to DNA and synthetic oligonucleotides have been performed by fluorescence methods, gel mobility shift analysis and footprinting assays. Footprinting studies have revealed that Pt-bis-netropsin and related molecules exhibit preferences for binding to the AT-spacer in OriS. The drugs stabilize structure of the AT-rich region and inhibit the fluctuation opening of AT-base pairs which is a prerequisite to unwinding of DNA by OBP. Kinetics of ATP-dependent unwinding of OriS in the presence and absence of netropsin derivatives have been studied by measuring the efficiency of Forster resonance energy transfer (FRET) between fluorophores attached to 5'- and 3'- ends of an oligonucleotide in the minimal OriS duplex. The results are consistent with the suggestion that OBP is the DNA Holiday junction (HJ) binding helicase. The protein induces conformation changes (bending and partial melting) of OriS duplexes and stimulates HJ formation in the absence of ATP. The antiviral activity of bis-netropsins is coupled with their ability to inhibit the fluctuation opening of АТ base pairs in the А + Т cluster and their capacity to stabilize the structure of the АТ-rich hairpin in the single-stranded oligonucleotide corresponding to the upper chain in the minimal duplex OriS. The antiviral activities of bis-netropsins in cell culture and their therapeutic effects on HSV1-infected laboratory animals have been studied.
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Affiliation(s)
- N P Bazhulina
- a V.A. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences , ul. Vavilova 32, 119991 , Moscow , Russia
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5
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Antoine TE, Park PJ, Shukla D. Glycoprotein targeted therapeutics: a new era of anti-herpes simplex virus-1 therapeutics. Rev Med Virol 2013; 23:194-208. [PMID: 23440920 DOI: 10.1002/rmv.1740] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 12/14/2012] [Accepted: 12/17/2012] [Indexed: 01/02/2023]
Abstract
Herpes simplex virus type-1 (HSV-1) is among the most common human pathogens worldwide. Its entry into host cells is an intricate process that relies heavily on the ability of the viral glycoproteins to bind host cellular proteins and to efficiently mediate fusion of the virus envelope with the cell membrane. Acquisition of HSV-1 results in a lifelong latent infection. Because of the cycles of reactivation from a latent state, much emphasis has been placed on the management of infection through the use of DNA synthesis inhibitors. However, new methods are needed to provide more effective treatment at earlier phases of the viral infection and to prevent the development of drug resistance by the virus. This review outlines the infection process and the common therapeutics currently used against the fundamental stages of HSV-1 replication and fusion. The remainder of this article will focus on a new approach for HSV-1 infection control and management, the concept of glycoprotein-receptor targeting.
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Affiliation(s)
- Thessicar E Antoine
- Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
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6
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Wong IN, Sayers JR, Sanders CM. Characterization of an unusual bipolar helicase encoded by bacteriophage T5. Nucleic Acids Res 2013; 41:4587-600. [PMID: 23435232 PMCID: PMC3632103 DOI: 10.1093/nar/gkt105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Bacteriophage T5 has a 120 kb double-stranded linear DNA genome encoding most of the genes required for its own replication. This lytic bacteriophage has a burst size of ∼500 new phage particles per infected cell, demonstrating that it is able to turn each infected bacterium into a highly efficient DNA manufacturing machine. To begin to understand DNA replication in this prodigious bacteriophage, we have characterized a putative helicase encoded by gene D2. We show that bacteriophage T5 D2 protein is the first viral helicase to be described with bipolar DNA unwinding activities that require the same core catalytic residues for unwinding in either direction. However, unwinding of partially single- and double-stranded DNA test substrates in the 3′–5′ direction is more robust and can be distinguished from the 5′–3′ activity by a number of features including helicase complex stability, salt sensitivity and the length of single-stranded DNA overhang required for initiation of helicase action. The presence of D2 in an early gene cluster, the identification of a putative helix-turn-helix DNA-binding motif outside the helicase core and homology with known eukaryotic and prokaryotic replication initiators suggest an involvement for this unusual helicase in DNA replication initiation.
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Affiliation(s)
- Io Nam Wong
- Department of Oncology, Institute for Cancer Studies
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7
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Bazhulina NP, Surovaya AN, Gursky YG, Andronova VL, Arkhipova VS, Golovkin MV, Nikitin AM, Galegov GA, Grokhovsky SL, Gursky GV. Inhibition of herpes simplex virus helicase UL9 by netropsin derivatives and antiviral activities of bis-netropsins. Biophysics (Nagoya-shi) 2012. [DOI: 10.1134/s0006350912020042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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8
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Muylaert I, Tang KW, Elias P. Replication and recombination of herpes simplex virus DNA. J Biol Chem 2011; 286:15619-24. [PMID: 21362621 DOI: 10.1074/jbc.r111.233981] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Replication of herpes simplex virus takes place in the cell nucleus and is carried out by a replisome composed of six viral proteins: the UL30-UL42 DNA polymerase, the UL5-UL8-UL52 helicase-primase, and the UL29 single-stranded DNA-binding protein ICP8. The replisome is loaded on origins of replication by the UL9 initiator origin-binding protein. Virus replication is intimately coupled to recombination and repair, often performed by cellular proteins. Here, we review new significant developments: the three-dimensional structures for the DNA polymerase, the polymerase accessory factor, and the single-stranded DNA-binding protein; the reconstitution of a functional replisome in vitro; the elucidation of the mechanism for activation of origins of DNA replication; the identification of cellular proteins actively involved in or responding to viral DNA replication; and the elucidation of requirements for formation of replication foci in the nucleus and effects on protein localization.
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Affiliation(s)
- Isabella Muylaert
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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9
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Surovaya AN, Grokhovsky SL, Gursky YG, Andronova VL, Arkhipova VS, Bazhulina NP, Galegov GA, Gursky GV. Complex of the herpes simplex virus initiator protein UL9 with DNA as a platform for the design of a new type of antiviral drugs. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910020077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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10
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Rennekamp AJ, Lieberman PM. Initiation of lytic DNA replication in Epstein-Barr virus: search for a common family mechanism. Future Virol 2010; 5:65-83. [PMID: 22468146 PMCID: PMC3314400 DOI: 10.2217/fvl.09.69] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Herpesviruses are a complex family of dsDNA viruses that are a major cause of human disease. All family members share highly related viral replication proteins, such as DNA polymerase, ssDNA-binding proteins and processivity factors. Consequently, it is generally thought that lytic replication occurs through a common and conserved mechanism. However, considerable evidence indicates that proteins controlling initiation of DNA replication vary greatly among the herepesvirus subfamilies. In this article, we focus on some of the known mechanisms that regulate Epstein-Barr virus lytic-cycle replication, and compare this to other herpesvirus family members. Our reading of the literature leads us to conclude that diverse viral mechanisms generate a common nucleoprotein prereplication structure that can be recognized by a highly conserved family of viral replication enzymes.
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Affiliation(s)
- Andrew J Rennekamp
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA and The University of Pennsylvania, Biomedical Graduate Program in Cell & Molecular Biology, The School of Medicine, Philadelphia, PA 19104, USA, Tel.: +1 215 898 9523, Fax: +1 251 898 0663,
| | - Paul M Lieberman
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA, Tel.: +1 215 898 9491, Fax: +1 215 898 0663,
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11
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Bugreev DV, Mazina OM, Mazin AV. Bloom syndrome helicase stimulates RAD51 DNA strand exchange activity through a novel mechanism. J Biol Chem 2009; 284:26349-59. [PMID: 19632996 PMCID: PMC2786030 DOI: 10.1074/jbc.m109.029371] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 07/21/2009] [Indexed: 01/08/2023] Open
Abstract
Loss or inactivation of BLM, a helicase of the RecQ family, causes Bloom syndrome, a genetic disorder with a strong predisposition to cancer. Although the precise function of BLM remains unknown, genetic data has implicated BLM in the process of genetic recombination and DNA repair. Previously, we demonstrated that BLM can disrupt the RAD51-single-stranded DNA filament that promotes the initial steps of homologous recombination. However, this disruption occurs only if RAD51 is present in an inactive ADP-bound form. Here, we investigate interactions of BLM with the active ATP-bound form of the RAD51-single-stranded DNA filament. Surprisingly, we found that BLM stimulates DNA strand exchange activity of RAD51. In contrast to the helicase activity of BLM, this stimulation does not require ATP hydrolysis. These data suggest a novel BLM function that is stimulation of the RAD51 DNA pairing. Our results demonstrate the important role of the RAD51 nucleoprotein filament conformation in stimulation of DNA pairing by BLM.
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Affiliation(s)
- Dmitry V. Bugreev
- From the Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102-1192 and
- the Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Science, Novosibirsk 630090, Russia
| | - Olga M. Mazina
- From the Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102-1192 and
| | - Alexander V. Mazin
- From the Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102-1192 and
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12
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Manolaridis I, Mumtsidu E, Konarev P, Makhov AM, Fullerton SW, Sinz A, Kalkhof S, McGeehan JE, Cary PD, Griffith JD, Svergun D, Kneale GG, Tucker PA. Structural and biophysical characterization of the proteins interacting with the herpes simplex virus 1 origin of replication. J Biol Chem 2009; 284:16343-16353. [PMID: 19329432 DOI: 10.1074/jbc.m806134200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The C terminus of the herpes simplex virus type 1 origin-binding protein, UL9ct, interacts directly with the viral single-stranded DNA-binding protein ICP8. We show that a 60-amino acid C-terminal deletion mutant of ICP8 (ICP8DeltaC) also binds very strongly to UL9ct. Using small angle x-ray scattering, the low resolution solution structures of UL9ct alone, in complex with ICP8DeltaC, and in complex with a 15-mer double-stranded DNA containing Box I of the origin of replication are described. Size exclusion chromatography, analytical ultracentrifugation, and electrophoretic mobility shift assays, backed up by isothermal titration calorimetry measurements, are used to show that the stoichiometry of the UL9ct-dsDNA15-mer complex is 2:1 at micromolar protein concentrations. The reaction occurs in two steps with initial binding of UL9ct to DNA (Kd approximately 6 nM) followed by a second binding event (Kd approximately 0.8 nM). It is also shown that the stoichiometry of the ternary UL9ct-ICP8DeltaC-dsDNA15-mer complex is 2:1:1, at the concentrations used in the different assays. Electron microscopy indicates that the complex assembled on the extended origin, oriS, rather than Box I alone, is much larger. The results are consistent with a simple model whereby a conformational switch of the UL9 DNA-binding domain upon binding to Box I allows the recruitment of a UL9-ICP8 complex by interaction between the UL9 DNA-binding domains.
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Affiliation(s)
- Ioannis Manolaridis
- From European Molecular Biology Laboratory, Hamburg Outstation, D-22603 Hamburg, Germany; Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom
| | - Eleni Mumtsidu
- From European Molecular Biology Laboratory, Hamburg Outstation, D-22603 Hamburg, Germany
| | - Peter Konarev
- From European Molecular Biology Laboratory, Hamburg Outstation, D-22603 Hamburg, Germany; Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Alexander M Makhov
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7295
| | - Stephen W Fullerton
- From European Molecular Biology Laboratory, Hamburg Outstation, D-22603 Hamburg, Germany
| | - Andrea Sinz
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, D-06120 Halle, Germany
| | - Stefan Kalkhof
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, D-06120 Halle, Germany
| | - John E McGeehan
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom
| | - Peter D Cary
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom
| | - Jack D Griffith
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7295
| | - Dmitri Svergun
- From European Molecular Biology Laboratory, Hamburg Outstation, D-22603 Hamburg, Germany; Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, 117333 Moscow, Russia
| | - Geoff G Kneale
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth PO1 2DT, United Kingdom
| | - Paul A Tucker
- From European Molecular Biology Laboratory, Hamburg Outstation, D-22603 Hamburg, Germany.
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13
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Makhov AM, Sen A, Yu X, Simon MN, Griffith JD, Egelman EH. The bipolar filaments formed by herpes simplex virus type 1 SSB/recombination protein (ICP8) suggest a mechanism for DNA annealing. J Mol Biol 2008; 386:273-9. [PMID: 19138689 DOI: 10.1016/j.jmb.2008.12.059] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 12/08/2008] [Accepted: 12/11/2008] [Indexed: 10/21/2022]
Abstract
Herpes simplex virus type 1 encodes a multifunctional protein, ICP8, which serves both as a single-strand binding protein and as a recombinase, catalyzing reactions involved in replication and recombination of the viral genome. In the presence of divalent ions and at low temperature, previous electron microscopic studies showed that ICP8 will form long left-handed helical filaments. Here, electron microscopic image reconstruction reveals that the filaments are bipolar, with an asymmetric unit containing two subunits of ICP8 that constitute a symmetrical dimer. This organization of the filament has been confirmed using scanning transmission electron microscopy. The pitch of the filaments is approximately 250 A, with approximately 6.2 dimers per turn. Docking of a crystal structure of ICP8 into the reconstructed filament shows that the C-terminal domain of ICP8, attached to the body of the subunit by a flexible linker containing approximately 10 residues, is packed into a pocket in the body of a neighboring subunit in the crystal in a similar manner as in the filament. However, the interactions between the large N-terminal domains are quite different in the filament from that observed in the crystal. A previously proposed model for ICP8 binding single-stranded DNA (ssDNA), based upon the crystal structure, leads to a model for a continuous strand of ssDNA near the filament axis. The bipolar nature of the ICP8 filaments means that a second strand of ssDNA would be running through this filament in the opposite orientation, and this provides a potential mechanism for how ICP8 anneals complementary ssDNA into double-stranded DNA, where each strand runs in opposite directions.
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Affiliation(s)
- Alexander M Makhov
- Lineberger Comprehensive Cancer Center, Department Microbiology and Immunology, University of North Carolina at Chapel Hill, 27517, USA
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14
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Mercorelli B, Sinigalia E, Loregian A, Palù G. Human cytomegalovirus DNA replication: antiviral targets and drugs. Rev Med Virol 2008; 18:177-210. [PMID: 18027349 DOI: 10.1002/rmv.558] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Human cytomegalovirus (HCMV) infection is associated with severe morbidity and mortality in immunocompromised individuals, in particular transplant recipients and AIDS patients, and is the most frequent congenital viral infection in humans. There are currently five drugs approved for HCMV treatment: ganciclovir and its prodrug valganciclovir, foscarnet, cidofovir and fomivirsen. These drugs have provided a major advance in HCMV disease management, but they suffer from poor bioavailability, significant toxicity and limited effectiveness, mainly due to the development of drug resistance. Fortunately, there are several novel and potentially very effective new compounds which are under pre-clinical and clinical evaluation and may address these limitations. This review focuses on HCMV proteins that are directly or indirectly involved in viral DNA replication and represent already established or potential novel antiviral targets, and describes both currently available drugs and new compounds against such protein targets.
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Affiliation(s)
- Beatrice Mercorelli
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, 35121 Padua, Italy
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15
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Naik AK, Raghavan SC. P1 nuclease cleavage is dependent on length of the mismatches in DNA. DNA Repair (Amst) 2008; 7:1384-91. [PMID: 18524693 DOI: 10.1016/j.dnarep.2008.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Revised: 04/16/2008] [Accepted: 04/17/2008] [Indexed: 10/22/2022]
Abstract
P1 nuclease is one of the most extensively used single-strand DNA specific nucleases in molecular biology. In modern biology, it is used as an enzymatic probe to detect altered DNA conformations. It is well documented that P1 cleaves single-stranded nucleic acids and single-stranded DNA regions. The fact that P1 can act under a wide range of conditions, including physiological pH and temperature make it the most commonly used enzymatic probe in DNA structural studies. Surprisingly, to this date, there is no study to characterize the influence of length of mismatches on P1 sensitivity. Using a series of radioactively labeled oligomeric DNA substrates-containing mismatches, we find that P1 nuclease cleavage is dependent on the length of mismatches. P1 does not cleave DNA when there is a single-base mismatch. P1 cleavage efficiency is optimum when mismatch length is 3 nt or more. Changing the position of the mismatches also does not make any difference in cleavage efficacy. These novel findings on P1 properties have implications for its use in DNA structure and DNA repair studies.
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Affiliation(s)
- Abani Kanta Naik
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
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16
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Gupta S, Chhibber M, Sinha S, Surolia A. Design of mechanism-based inhibitors of transthyretin amyloidosis: studies with biphenyl ethers and new structural templates. J Med Chem 2007; 50:5589-99. [PMID: 17948976 DOI: 10.1021/jm0700159] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transthyretin (TTR), a tetrameric thyroxine (T4) carrier protein, is associated with a variety of amyloid diseases. In this study, we explore the potential of biphenyl ethers (BPE), which are shown to interact with a high affinity to its T4 binding site thereby preventing its aggregation and fibrillogenesis. They prevent fibrillogenesis by stabilizing the tetrameric ground state of transthyretin. Additionally, we identify two new structural templates (2-(5-mercapto-[1,3,4]oxadiazol-2-yl)-phenol and 2,3,6-trichloro-N-(4H-[1,2,4]triazol-3-yl) represented as compounds 11 and 12, respectively, throughout the manuscript) exhibiting the ability to arrest TTR amyloidosis. The dissociation constants for the binding of BPEs and compound 11 and 12 to TTR correlate with their efficacies of inhibiting amyloidosis. They also have the ability to inhibit the elongation of intermediate fibrils as well as show nearly complete (>90%) disruption of the preformed fibrils. The present study thus establishes biphenyl ethers and compounds 11 and 12 as very potent inhibitors of TTR fibrillization and inducible cytotoxicity.
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Affiliation(s)
- Sarika Gupta
- Molecular Biophysics Unit, Indian Institute of Sciences, Bangalore 560012, India
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17
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Schildgen O, Gräper S, Blümel J, Matz B. Genome replication and progeny virion production of herpes simplex virus type 1 mutants with temperature-sensitive lesions in the origin-binding protein. J Virol 2005; 79:7273-8. [PMID: 15890967 PMCID: PMC1112152 DOI: 10.1128/jvi.79.11.7273-7278.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Genome replication of herpes simplex viruses (HSV) in cultured cells is thought to be started by the action of the virus-encoded origin-binding protein (OBP). In experiments using two HSV-1 mutants with temperature-sensitive lesions in the helicase domain of OBP, we demonstrated that this function is essential during the first 6 hours of the lytic cycle. Once DNA synthesis has started, this function is no longer required, suggesting that origin-driven initiation of viral DNA replication is a single event rather than a continuous process.
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Affiliation(s)
- Oliver Schildgen
- Institut für Medizinische Mikrobiologie und Immunologie, Universität Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany
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18
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Colletti KS, Xu Y, Yamboliev I, Pari GS. Human cytomegalovirus UL84 is a phosphoprotein that exhibits UTPase activity and is a putative member of the DExD/H box family of proteins. J Biol Chem 2005; 280:11955-60. [PMID: 15778228 DOI: 10.1074/jbc.c400603200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human cytomegalovirus (HCMV) UL84 is required for lytic DNA replication and is proposed to be the key factor in initiation of viral DNA synthesis. We now show that UL84 has a high degree of homology to the DExD/H (where x can be any amino acid) box family of helicases, displays UTPase activity, and is phosphorylated at serine residues. Affinity column-purified UL84-FLAG fusion protein was used in an in vitro nucleoside triphosphatase (NTPase) assay to show that UL84 has NTPase activity, preferring UTP. This UTPase activity was linear with respect to enzyme concentration and slightly enhanced by the addition of nucleic acid substrates. UL84 UTPase was the highest at low salt concentrations, a pH of 7.5, and a temperature of 45 degrees C. The enzyme preferred Mg2+ as the divalent cation but was also able to catalyze the UTPase reaction in the presence of Mn2+, Ca2+, and Zn2+ albeit at lower levels. The evidence presented here suggests that the UL84 UTPase activity may be part of an energy-generating system for helicase activity associated with the initiation of HCMV DNA replication.
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Affiliation(s)
- Kelly S Colletti
- University of Nevada-Reno, Department of Microbiology & Immunology and the Cell and Molecular Biology Program, Reno, Nevada 89557, USA
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19
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Mapelli M, Panjikar S, Tucker PA. The crystal structure of the herpes simplex virus 1 ssDNA-binding protein suggests the structural basis for flexible, cooperative single-stranded DNA binding. J Biol Chem 2004; 280:2990-7. [PMID: 15507432 DOI: 10.1074/jbc.m406780200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
All organisms including animal viruses use specific proteins to bind single-stranded DNA rapidly in a non-sequence-specific, flexible, and cooperative manner during the DNA replication process. The crystal structure of a 60-residue C-terminal deletion construct of ICP8, the major single-stranded DNA-binding protein from herpes simplex virus-1, was determined at 3.0 A resolution. The structure reveals a novel fold, consisting of a large N-terminal domain (residues 9-1038) and a small C-terminal domain (residues 1049-1129). On the basis of the structure and the nearest neighbor interactions in the crystal, we have presented a model describing the site of single-stranded DNA binding and explaining the basis for cooperative binding. This model agrees with the beaded morphology observed in electron micrographs.
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Affiliation(s)
- Marina Mapelli
- European Molecular Biology Laboratory, Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany
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20
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Makhov AM, Taylor DW, Griffith JD. Two-dimensional crystallization of herpes simplex virus type 1 single-stranded DNA-binding protein, ICP8, on a lipid monolayer. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1701:101-8. [PMID: 15450179 DOI: 10.1016/j.bbapap.2004.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Revised: 06/14/2004] [Accepted: 06/17/2004] [Indexed: 11/29/2022]
Abstract
Herpes simplex virus type 1 single-stranded DNA-binding protein (ICP8) has been crystallized on a positively charged lipid monolayer. The crystals belong to the planar group p2 with a=39 nm, b=23.2 nm and gamma=87.2 degrees. The projected map of ICP8 crystals calculated at a resolution of 3.9 nm shows four ICP8 monomers per unit cell with the crystals formed by a parallel arrangement of 16.2 nm helical ICP8 filaments. This novel filamentous form has not been reported before. The ICP8 monomers show different appearances in projection, suggesting that they may adopt different orientations, probably reflecting the strong intermolecular and lipid-filament interactions in the crystal. When the 23 nm diameter filaments formed by ICP8 in solution at low temperature in the presence of magnesium were generated and then layered on the phospholipid monolayer, highly ordered arrays of an 8.5 nm filament with a shallow 31.2 nm pitch were observed and reconstruction revealed a double-helical structure.
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Affiliation(s)
- Alexander M Makhov
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Campus Box 7295, Chapel Hill, NC 27599-7295, USA.
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21
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Grose C, Tyler S, Peters G, Hiebert J, Stephens GM, Ruyechan WT, Jackson W, Storlie J, Tipples GA. Complete DNA sequence analyses of the first two varicella-zoster virus glycoprotein E (D150N) mutant viruses found in North America: evolution of genotypes with an accelerated cell spread phenotype. J Virol 2004; 78:6799-807. [PMID: 15194755 PMCID: PMC421634 DOI: 10.1128/jvi.78.13.6799-6807.2004] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Varicella-zoster virus (VZV) is considered to be one of the most genetically stable of all the herpesviruses. Yet two VZV strains with a D150N missense mutation within the gE glycoprotein were isolated in North America in 1998 and 2002. The mutant strains have an accelerated cell spread phenotype, which distinguishes them from all wild-type and laboratory viruses. Since the VZV genome contains 70 additional open reading frames (ORFs), the possibility existed that the phenotypic change was actually due to an as-yet-undiscovered mutation or deletion elsewhere in the genome. To exclude this hypothesis, the entire genomes of the two mutant viruses were sequenced and found to contain 124,883 (VZV-MSP) and 125,459 (VZV-BC) nucleotides. Coding single-nucleotide polymorphisms (SNPs) were identified in 14 ORFs. One missense mutation was discovered in gH, but none was found in gB, gI, gL, or gK. There were no coding SNPs in the major regulatory protein ORF 62. One polymorphism was discovered which could never have been anticipated based on current knowledge of herpesvirus genomics, namely, the origins of replication differed from those in the prototype strain but not in a manner expected to affect cell spread. When the two complete mutant VZV sequences were surveyed in their entirety, the most reasonable conclusion was that the increased cell spread phenotype was dependent substantially or solely on the single D150N polymorphism in glycoprotein gE. The genomic results also expanded the evolutionary database by identifying which VZV ORFs were more likely to mutate over time.
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Affiliation(s)
- Charles Grose
- Department of Pediatrics, University of Iowa, Iowa City, 52242, USA.
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22
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Macao B, Olsson M, Elias P. Functional properties of the herpes simplex virus type I origin-binding protein are controlled by precise interactions with the activated form of the origin of DNA replication. J Biol Chem 2004; 279:29211-7. [PMID: 15133043 DOI: 10.1074/jbc.m400371200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The herpes simplex virus, type I origin-binding protein, OBP, is a superfamily II DNA helicase encoded by the UL9 gene. OBP binds in a sequence-specific and cooperative way to the viral origin of replication oriS. OBP may unwind partially and introduce a hairpin into the double-stranded origin of replication. The formation of the novel conformation referred to as oriS* also requires the single-stranded DNA-binding protein, ICP8, and ATP hydrolysis. OBP forms a stable complex with oriS*. The hairpin in oriS* provides a site for sequence-specific attachment, and a single-stranded region triggers ATP hydrolysis. Here we use Escherichia coli exonuclease I to map the binding of the C-terminal domain of OBP to the hairpin and the helicase domains to the single-stranded tail. The helicase domains cover a stretch of 23 nucleotides of single-stranded DNA. Using streptavidin-coated magnetic beads, we show that OBP may bind two copies of double-stranded DNA (one biotin-labeled and the other one radioactively labeled) but only one copy of oriS*. It is the length of the single-stranded tail that determines the stoichiometry of OBP.DNA complexes. OBP interacts with the bases of the single-stranded tail, and ATP hydrolysis is triggered by position-specific interactions between OBP and bases in the single-stranded tail of oriS*.
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Affiliation(s)
- Bertil Macao
- Department of Medical Biochemistry, Göteborg University, Box 440, S-405 30 Göteborg, Sweden
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23
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Trego KS, Parris DS. Functional interaction between the herpes simplex virus type 1 polymerase processivity factor and origin-binding proteins: enhancement of UL9 helicase activity. J Virol 2004; 77:12646-59. [PMID: 14610187 PMCID: PMC262563 DOI: 10.1128/jvi.77.23.12646-12659.2003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The origin (ori)-binding protein of herpes simplex virus type 1 (HSV-1), encoded by the UL9 open reading frame, has been shown to physically interact with a number of cellular and viral proteins, including three HSV-1 proteins (ICP8, UL42, and UL8) essential for ori-dependent DNA replication. In this report, it is demonstrated for the first time that the DNA polymerase processivity factor, UL42 protein, provides accessory function to the UL9 protein by enhancing the 3'-to-5' helicase activity of UL9 on partially duplex nonspecific DNA substrates. UL42 fails to enhance the unwinding activity of a noncognate helicase, suggesting that enhancement of unwinding requires the physical interaction between UL42 and UL9. UL42 increases the steady-state rate for unwinding a 23/38-mer by UL9, but only at limiting UL9 concentrations, consistent with a role in increasing the affinity of UL9 for DNA. Optimum enhancement of unwinding was observed at UL42/UL9 molecular ratios of 4:1, although enhancement was reduced when high UL42/DNA ratios were present. Under the assay conditions employed, UL42 did not alter the rate constant for dissociation of UL9 from the DNA substrate. UL42 also did not significantly reduce the lag period which was observed following the addition of UL9 to DNA, regardless of whether UL42 was added to DNA prior to or at the same time as UL9. Moreover, addition of UL42 to ongoing unwinding reactions increased the steady-state rate for unwinding, but only after a 10- to 15-min lag period. Thus, the increased affinity of UL9 for DNA most likely is the result of an increase in the rate constant for binding of UL9 to DNA, and it explains why helicase enhancement is observed only at subsaturating concentrations of UL9 with respect to DNA. In contrast, ICP8 enhances unwinding at both saturating and subsaturating UL9 concentrations and reduces or eliminates the lag period. The different means by which ICP8 and UL42 enhance the ability of UL9 to unwind DNA suggest that these two members of the presumed functional replisome may act synergistically on UL9 to effect initiation of HSV-1 DNA replication in vivo.
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Affiliation(s)
- Kelly S Trego
- Department of Molecular Genetics, Immunology, and Medical Genetics, Ohio State University, Columbus, Ohio 43210, USA
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24
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Taylor TJ, McNamee EE, Day C, Knipe DM. Herpes simplex virus replication compartments can form by coalescence of smaller compartments. Virology 2003; 309:232-47. [PMID: 12758171 DOI: 10.1016/s0042-6822(03)00107-7] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Herpes simplex virus (HSV) uses intranuclear compartmentalization to concentrate the viral and cellular factors required for the progression of the viral life cycle. Processes as varied as viral DNA replication, late gene expression, and capsid assembly take place within discrete structures within the nucleus called replication compartments. Replication compartments are hypothesized to mature from a few distinct structures, called prereplicative sites, that form adjacent to cellular nuclear matrix-associated ND10 sites. During productive infection, the HSV single-stranded DNA-binding protein ICP8 localizes to replication compartments. To further the understanding of replication compartment maturation, we have constructed and characterized a recombinant HSV-1 strain that expresses an ICP8 molecule with green fluorescent protein (GFP) fused to its C terminus. In transfected Vero cells that were infected with HSV, the ICP8-GFP protein localized to prereplicative sites in the presence of the viral DNA synthesis inhibitor phosphonoacetic acid (PAA) or to replication compartments in the absence of PAA. A recombinant HSV-1 strain expressing the ICP8-GFP virus replicated in Vero cells, but the yield was increased by 150-fold in an ICP8-complementing cell line. Using the ICP8-GFP protein as a marker for replication compartments, we show here that these structures start as punctate structures early in infection and grow into large, globular structures that eventually fill the nucleus. Large replication compartments were formed by small structures that either moved through the nucleus to merge with adjacent compartments or remained relatively stationary within the nucleus and grew by accretion and fused with neighboring structures.
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Affiliation(s)
- Travis J Taylor
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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25
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Taylor TJ, Knipe DM. C-terminal region of herpes simplex virus ICP8 protein needed for intranuclear localization. Virology 2003; 309:219-31. [PMID: 12758170 DOI: 10.1016/s0042-6822(03)00108-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The herpes simplex virus single-stranded DNA-binding protein, ICP8, localizes initially to structures in the nucleus called prereplicative sites. As replication proceeds, these sites mature into large globular structures called replication compartments. The details of what signals or proteins are involved in the redistribution of viral and cellular proteins within the nucleus between prereplicative sites and replication compartments are poorly understood; however, we showed previously that the dominant-negative d105 ICP8 does not localize to prereplicative sites and prevents the localization of other viral proteins to prereplicative sites (J. Virol. 74 (2000) 10122). Within the residues deleted in d105 (1083 to 1168), we identified a region between amino acid residues 1080 and 1135 that was predicted by computer models to contain two alpha-helices, one with considerable amphipathic nature. We used site-specific and random mutagenesis techniques to identify residues or structures within this region that are required for proper ICP8 localization within the nucleus. Proline substitutions in the predicted helix generated ICP8 molecules that did not localize to prereplicative sites and acted as dominant-negative inhibitors. Other substitutions that altered the charged residues in the predicted alpha-helix to alanine or leucine residues had little or no effect on ICP8 intranuclear localization. The predicted alpha-helix was dispensable for the interaction of ICP8 with the U(L)9 origin-binding protein. We propose that this C-terminal alpha-helix is required for localization of ICP8 to prereplicative sites by binding viral or cellular factors that target or retain ICP8 at specific intranuclear sites.
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Affiliation(s)
- Travis J Taylor
- Department of Microbiology and Molecular, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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26
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Makhov AM, Lee SSK, Lehman IR, Griffith JD. Origin-specific unwinding of herpes simplex virus 1 DNA by the viral UL9 and ICP8 proteins: visualization of a specific preunwinding complex. Proc Natl Acad Sci U S A 2003; 100:898-903. [PMID: 12552114 PMCID: PMC298698 DOI: 10.1073/pnas.0237171100] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Herpes simplex virus 1 contains three origins of replication; two copies of oriS and one of a similar sequence, oriL. Here, the combined action of multiple factors known or thought to influence the opening of oriS are examined. These include the viral origin-binding protein, UL9, and single-strand binding protein ICP8, host cell topoisomerase I, and superhelicity of the DNA template. By using electron microscopy, it was observed that when ICP8 and UL9 proteins were added together to oriS-containing supertwisted DNA, a discrete preunwinding complex was formed at oriS on 40% of the molecules, which was shown by double immunolabeling electron microscopy to contain both proteins. This complex was relatively stable to extreme dilution. Addition of ATP led to the efficient unwinding of approximately 50% of the DNA templates. Unwinding proceeded until the acquisition of a high level of positive supertwists in the remaining duplex DNA inhibited further unwinding. Addition of topoisomerase I allowed further unwinding, opening >1 kb of DNA around oriS.
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Affiliation(s)
- Alexander M Makhov
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-7295, USA
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27
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Boehmer PE, Villani G. Herpes simplex virus type-1: a model for genome transactions. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2003; 75:139-71. [PMID: 14604012 DOI: 10.1016/s0079-6603(03)75005-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In many respects, HSV-1 is the prototypic herpes virus. However, HSV-1 also serves as an excellent model system to study genome transactions, including DNA replication, homologous recombination, and the interaction of DNA replication enzymes with DNA damage. Like eukaryotic chromosomes, the HSV-1 genome contains multiple origins of replication. Replication of the HSV-1 genome is mediated by the concerted action of several virus-encoded proteins that are thought to assemble into a multiprotein complex. Several host-encoded factors have also been implicated in viral DNA replication. Furthermore, replication of the HSV-1 genome is known to be closely associated with homologous recombination that, like in many cellular organisms, may function in recombinational repair. Finally, recent data have shed some light on the interaction of essential HSV-1 replication proteins, specifically its DNA polymerase and DNA helicases, with damaged DNA.
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Affiliation(s)
- Paul E Boehmer
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, PO Box 016129, Miami, FL 33101-6129, USA
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28
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Aslani A, Olsson M, Elias P. ATP-dependent unwinding of a minimal origin of DNA replication by the origin-binding protein and the single-strand DNA-binding protein ICP8 from herpes simplex virus type I. J Biol Chem 2002; 277:41204-12. [PMID: 12183471 DOI: 10.1074/jbc.m208270200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Herpes simplex virus type I origin-binding protein, OBP, is encoded by the UL9 gene. OBP binds the origin of DNA replication, oriS, in a cooperative and sequence-specific manner. OBP is also an ATP-dependent DNA helicase. We have recently shown that single-stranded oriS folds into a unique and evolutionarily conserved conformation, oriS*, which is stably bound by OBP. OriS* contains a stable hairpin formed by complementary base pairing between box I and box III in oriS. Here we show that OBP, in the presence of the single-stranded DNA-binding protein ICP8, can convert an 80-base pair double-stranded minimal oriS fragment to oriS* and form an OBP-oriS* complex. The formation of an OBP-oriS* complex requires hydrolysable ATP. We also demonstrate that OBP in the presence of ICP8 and ATP promotes slow but specific and complete unwinding of duplex minimal oriS. The possibility that the OBP-oriS* complex may serve as an assembly site for the herpes virus replisome is discussed.
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Affiliation(s)
- Alireza Aslani
- Department of Medical Biochemistry, Göteborg University, Box 440, SE 405 30 Göteborg University, Sweden
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29
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Cohrs RJ, Wischer J, Essman C, Gilden DH. Characterization of varicella-zoster virus gene 21 and 29 proteins in infected cells. J Virol 2002; 76:7228-38. [PMID: 12072522 PMCID: PMC136324 DOI: 10.1128/jvi.76.14.7228-7238.2002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Varicella-zoster virus (VZV) transcription is limited in latently infected human ganglia. Note that much of the transcriptional capacity of the virus genome has not been analyzed in detail; to date, only VZV genes mapping to open reading frames (ORFs) 4, 21, 29, 62, and 63 have been detected. ORF 62 encodes the major immediate-early virus transcription transactivator IE62, ORF 29 encodes the major virus DNA binding protein, and ORF 21 encodes a protein associated with the developing virus nucleocapsid. We analyzed the cellular location of proteins encoded by ORF 21 (21p) and ORF 29 (29p), their phosphorylation state during productive infection, and their ability form a protein-protein complex. The locations of both 21p and 29p within infected cells mimic those of their herpes simplex virus type 1 (HSV-1) homologues (UL37 and ICP8); however, unlike these homologues, 21p is not phosphorylated and neither 21p nor 29p exhibits a protein-protein interaction. Transient transfection assays to determine the effect of 21p and 29p on transcription from VZV gene 20, 21, 28, and 29 promoters revealed no significant activation of transcription by 21p or 29p from any of the VZV gene promoters tested, and 21p did not significantly modulate the ability of IE62 to activate gene transcription. A modest increase in IE62-induced activation of gene 28 and 29 promoters was seen in the presence of 29p; however, IE62-induced activation of gene 28 and 29 promoters was reduced in the presence of 21p. A Saccharomyces cerevisiae two-hybrid analysis of 21p indicated that the protein can activate transcription when tethered within a responsive promoter. Together, the data reveal that while VZV gene 21 and HSV-1 UL37 share homology at the nucleic acid level, these proteins differ functionally.
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Affiliation(s)
- Randall J Cohrs
- Department of Neurology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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30
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Eom CY, Lehman IR. The human DnaJ protein, hTid-1, enhances binding of a multimer of the herpes simplex virus type 1 UL9 protein to oris, an origin of viral DNA replication. Proc Natl Acad Sci U S A 2002; 99:1894-8. [PMID: 11854491 PMCID: PMC122290 DOI: 10.1073/pnas.042689499] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have identified cellular proteins that interact with the herpes simplex virus type 1 (HSV-1) origin-binding protein (UL9 protein) by screening a HeLa cell complementary DNA library by using the yeast two-hybrid system. Approximately 7 x 10(5) colonies were screened. Five of the 48 positive clones contained cDNAs that encoded the p150(Glued) component of the dynactin complex, three contained cDNAs for the neural F Box 42-kDa protein (NFB42), which is highly enriched in neural tissue, and three contained hTid-1, a human homologue of the bacterial DnaJ protein. We have focused in this report on the interaction of the viral UL9 protein with the cellular hTid-1. In vitro immunoprecipitation experiments confirmed that hTid-1 interacts with the UL9 protein. Electrophoretic mobility-shift assays indicated that the hTid-1 enhances the binding of UL9 protein to an HSV-1 origin, ori(s), and facilitates formation of the multimer from the dimeric UL9 protein. hTid-1 had no effect on the DNA-dependent ATPase or helicase activities associated with the UL9 protein. These findings implicate hTid-1 in HSV-1 DNA replication, and suggest that this cellular protein may provide a chaperone function analogous to the DnaJ protein in Escherichia coli DNA replication.
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Affiliation(s)
- Chi-Yong Eom
- Department of Biochemistry, Beckman Center, Stanford University School of Medicine, Stanford, CA 94305-5307, USA
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31
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Tanguy Le Gac N, Boehmer PE. Activation of the herpes simplex virus type-1 origin-binding protein (UL9) by heat shock proteins. J Biol Chem 2002; 277:5660-6. [PMID: 11711536 DOI: 10.1074/jbc.m108316200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Heat shock proteins participate in the initiation of DNA replication of different organisms by facilitating the assembly of initiation complexes. We have examined the effects of human heat shock proteins (Hsp40 and Hsp70) on the interaction of the herpes simplex virus type-1 initiator protein (UL9) with oriS, one of the viral origins of replication. Hsp40 and Hsp70 act substoichiometrically to increase the affinity of UL9 for oriS. The major contributor to this effect is Hsp40. Heat shock proteins also stimulate the ATPase activity of UL9 with oriS and increase opening of the origin. In contrast, heat shock proteins have no effect on the origin-independent activities of UL9 suggesting that their role is not merely in refolding denatured protein. These observations are consistent with a role for heat shock proteins in activating UL9 to efficiently initiate viral origin-dependent DNA replication. The action of heat shock proteins in this capacity is analogous to their role in activating the initiator proteins of other organisms.
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Affiliation(s)
- Nicolas Tanguy Le Gac
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida 33101-6129, USA
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