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Zhou T, Wang M, Cheng A, Yang Q, Tian B, Wu Y, Jia R, Chen S, Liu M, Zhao XX, Ou X, Mao S, Sun D, Zhang S, Zhu D, Huang J, Gao Q, Yu Y, Zhang L. Regulation of alphaherpesvirus protein via post-translational phosphorylation. Vet Res 2022; 53:93. [PMID: 36397147 PMCID: PMC9670612 DOI: 10.1186/s13567-022-01115-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022] Open
Abstract
An alphaherpesvirus carries dozens of viral proteins in the envelope, tegument and capsid structure, and each protein plays an indispensable role in virus adsorption, invasion, uncoating and release. After infecting the host, a virus eliminates unfavourable factors via multiple mechanisms to escape or suppress the attack of the host immune system. Post-translational modification of proteins, especially phosphorylation, regulates changes in protein conformation and biological activity through a series of complex mechanisms. Many viruses have evolved mechanisms to leverage host phosphorylation systems to regulate viral protein activity and establish a suitable cellular environment for efficient viral replication and virulence. In this paper, viral protein kinases and the regulation of viral protein function mediated via the phosphorylation of alphaherpesvirus proteins are described. In addition, this paper provides new ideas for further research into the role played by the post-translational modification of viral proteins in the virus life cycle, which will be helpful for understanding the mechanisms of viral infection of a host and may lead to new directions of antiviral treatment.
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2
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Alekseev O, Donegan WE, Donovan KR, Limonnik V, Azizkhan-Clifford J. HSV-1 Hijacks the Host DNA Damage Response in Corneal Epithelial Cells through ICP4-Mediated Activation of ATM. Invest Ophthalmol Vis Sci 2021; 61:39. [PMID: 32543665 PMCID: PMC7415316 DOI: 10.1167/iovs.61.6.39] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Purpose Herpes simplex virus type I (HSV-1) infection of corneal epithelial cells activates ataxia telangiectasia mutated (ATM), an apical kinase in the host DNA damage response pathway, whose activity is necessary for the progression of lytic HSV-1 infection. The purpose of this study is to investigate the mechanism of ATM activation by HSV-1 in the corneal epithelium, as well as its functional significance. Methods Mechanistic studies were performed in cultured human corneal epithelial cell lines (hTCEpi, HCE), as well as in esophageal (EPC2) and oral (OKF6) cell lines. Transfection-based experiments were performed in HEK293 cells. HSV-1 infection was carried out using the wild-type KOS strain, various mutant strains (tsB7, d120, 7134, i13, n208), and bacterial artificial chromosomes (fHSVΔpac, pM24). Inhibitors of ATM (KU-55933), protein synthesis (cycloheximide), and viral DNA replication (phosphonoacetic acid) were used. Outcomes of infection were assayed using Western blotting, qRT-PCR, immunofluorescence, and comet assay. Results This study demonstrates that HSV-1-mediated ATM activation in corneal epithelial cells relies on the viral immediate early gene product ICP4 and requires the presence of the viral genome in the host nucleus. We show that ATM activation is independent of viral genome replication, the ICP0 protein, and the presence of DNA lesions. Interestingly, ATM activity appears to be necessary at the onset of infection, but dispensable at the later stages. Conclusions This study expands our understanding of HSV-1 virus-host interactions in the corneal epithelium and identifies potential areas of future investigation and therapeutic intervention in herpes keratitis.
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Singh H, Kaur K, Singh M, Kaur G, Singh P. Plant Cyclophilins: Multifaceted Proteins With Versatile Roles. FRONTIERS IN PLANT SCIENCE 2020; 11:585212. [PMID: 33193535 PMCID: PMC7641896 DOI: 10.3389/fpls.2020.585212] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/22/2020] [Indexed: 05/03/2023]
Abstract
Cyclophilins constitute a family of ubiquitous proteins that bind cyclosporin A (CsA), an immunosuppressant drug. Several of these proteins possess peptidyl-prolyl cis-trans isomerase (PPIase) activity that catalyzes the cis-trans isomerization of the peptide bond preceding a proline residue, essential for correct folding of the proteins. Compared to prokaryotes and other eukaryotes studied until now, the cyclophilin gene families in plants exhibit considerable expansion. With few exceptions, the role of the majority of these proteins in plants is still a matter of conjecture. However, recent studies suggest that cyclophilins are highly versatile proteins with multiple functionalities, and regulate a plethora of growth and development processes in plants, ranging from hormone signaling to the stress response. The present review discusses the implications of cyclophilins in different facets of cellular processes, particularly in the context of plants, and provides a glimpse into the molecular mechanisms by which these proteins fine-tune the diverse physiological pathways.
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Affiliation(s)
- Harpreet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
- Department of Bioinformatics, Hans Raj Mahila Maha Vidyalaya, Jalandhar, India
| | - Kirandeep Kaur
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
| | - Mangaljeet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
| | - Gundeep Kaur
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
- William Harvey Heart Centre, Queen Mary University of London, London, United Kingdom
| | - Prabhjeet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
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4
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Ge L, Zhang K, Cao X, Weng Y, Liu B, Mao P, Ma X. Sequence characteristics of Medicago truncatula cyclophilin family members and function analysis of MsCYP20-3B involved in axillary shoot development. Mol Biol Rep 2019; 47:907-919. [PMID: 31741262 DOI: 10.1007/s11033-019-05183-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/05/2019] [Indexed: 12/25/2022]
Abstract
Cyclophilins (CYPs) belonging to the immunophilin family are present in all organisms and widely distributed in various cells associated with the activity of peptidyl-prolyl cis/trans isomerase. Plant CYPs are members of a multi-gene family and are involved in a series of biological processes. However, little is known about their structure, evolution, developmental expression and functional analysis in Medicago truncatula. In this study, a total of 33 CYP genes were identified and found to be unevenly distributed on eight chromosomes. Among them, 21 are single-domain and 12 are multi-domain proteins, and most were predicted to be localized in the cytosol, nucleus or chloroplast. Phylogenetic and gene structure analysis revealed seven segmental gene pairs, indicating that segmental duplication probably made a large contribution to the expansion of MtCYP gene family. Furthermore, gene expression analysis revealed that about 10 MtCYP genes (were) highly expressed involved in vegetative and reproduction tissues in M. truncatula, and MsCYP20-3B was mainly upregulated in stems, leaves and flower buds in alfalfa (Medicago sativa). Overexpression of MsCYP20-3B was shown to regulate axillary shoot development associated with higher jasmonic acid and abscisic acid contents in M. truncatula. Our study suggests the importance of the CYP genes family in development, reproduction and stress responses, and provides a reference for future studies and application of CYP genes for alfalfa genetic improvement.
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Affiliation(s)
- Lingqiao Ge
- College of Grassland Science and Technology, China Agricultural University, Beijing, China
| | - Kun Zhang
- College of Grassland Science and Technology, China Agricultural University, Beijing, China
| | - Xiaohui Cao
- College of Grassland Science and Technology, China Agricultural University, Beijing, China
| | - Yinyin Weng
- College of Grassland Science and Technology, China Agricultural University, Beijing, China
| | - Bei Liu
- College of Grassland Science and Technology, China Agricultural University, Beijing, China
| | - Peisheng Mao
- College of Grassland Science and Technology, China Agricultural University, Beijing, China.,Key Laboratory of Pratacultural Science, Beijing Municipality, Yuanmingyuan West Road, Haidian District, Beijing, 100193, China
| | - Xiqing Ma
- College of Grassland Science and Technology, China Agricultural University, Beijing, China. .,Key Laboratory of Pratacultural Science, Beijing Municipality, Yuanmingyuan West Road, Haidian District, Beijing, 100193, China.
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5
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Xiong F, Ren JJ, Yu Q, Wang YY, Kong LJ, Otegui MS, Wang XL. AtBUD13 affects pre-mRNA splicing and is essential for embryo development in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:714-726. [PMID: 30720904 DOI: 10.1111/tpj.14268] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/24/2019] [Accepted: 01/30/2019] [Indexed: 05/03/2023]
Abstract
Pre-mRNA splicing is an important step for gene expression regulation. Yeast Bud13p (bud-site selection protein 13) regulates the budding pattern and pre-mRNA splicing in yeast cells; however, no Bud13p homologs have been identified in plants. Here, we isolated two mutants that carry T-DNA insertions at the At1g31870 locus and shows early embryo lethality and seed abortion. At1g31870 encodes an Arabidopsis homolog of yeast Bud13p, AtBUD13. Although AtBUD13 homologs are widely distributed in eukaryotic organisms, phylogenetic analysis revealed that their protein domain organization is more complex in multicellular species. AtBUD13 is expressed throughout plant development including embryogenesis and AtBUD13 proteins is localized in the nucleus in Arabidopsis. RNA-seq analysis revealed that AtBUD13 mutation predominantly results in the intron retention, especially for shorter introns (≤100 bases). Within this group of genes, we identified 52 genes involved in embryogenesis, out of which 22 are involved in nucleic acid metabolism. Our results demonstrate that AtBUD13 plays critical roles in early embryo development by effecting pre-mRNA splicing.
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Affiliation(s)
- Feng Xiong
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Jing-Jing Ren
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Qin Yu
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Yu-Yi Wang
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Lan-Jing Kong
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Marisa S Otegui
- Departments of Botany and Genetics, University of Wisconsin-Madison, Madison, 53706, USA
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, 53706, USA
| | - Xiu-Ling Wang
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
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6
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Bryant NA, Wilkie GS, Russell CA, Compston L, Grafham D, Clissold L, McLay K, Medcalf L, Newton R, Davison AJ, Elton DM. Genetic diversity of equine herpesvirus 1 isolated from neurological, abortigenic and respiratory disease outbreaks. Transbound Emerg Dis 2018; 65:817-832. [PMID: 29423949 PMCID: PMC5947664 DOI: 10.1111/tbed.12809] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Indexed: 12/14/2022]
Abstract
Equine herpesvirus 1 (EHV‐1) causes respiratory disease, abortion, neonatal death and neurological disease in equines and is endemic in most countries. The viral factors that influence EHV‐1 disease severity are poorly understood, and this has hampered vaccine development. However, the N752D substitution in the viral DNA polymerase catalytic subunit has been shown statistically to be associated with neurological disease. This has given rise to the term “neuropathic strain,” even though strains lacking the polymorphism have been recovered from cases of neurological disease. To broaden understanding of EHV‐1 diversity in the field, 78 EHV‐1 strains isolated over a period of 35 years were sequenced. The great majority of isolates originated from the United Kingdom and included in the collection were low passage isolates from respiratory, abortigenic and neurological outbreaks. Phylogenetic analysis of regions spanning 80% of the genome showed that up to 13 viral clades have been circulating in the United Kingdom and that most of these are continuing to circulate. Abortion isolates grouped into nine clades, and neurological isolates grouped into five. Most neurological isolates had the N752D substitution, whereas most abortion isolates did not, although three of the neurological isolates from linked outbreaks had a different polymorphism. Finally, bioinformatic analysis suggested that recombination has occurred between EHV‐1 clades, between EHV‐1 and equine herpesvirus 4, and between EHV‐1 and equine herpesvirus 8.
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Affiliation(s)
- N A Bryant
- Animal Health Trust, Kentford, Newmarket, Suffolk, UK
| | - G S Wilkie
- MRC-University of Glasgow Centre for Virus Research, Glasgow, UK
| | - C A Russell
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - L Compston
- Animal Health Trust, Kentford, Newmarket, Suffolk, UK
| | - D Grafham
- Sheffield Children's NHS Foundation Trust, Sheffield, South Yorkshire, UK
| | - L Clissold
- Earlham Institute, Norwich Research Park, Norwich, Norfolk, UK
| | - K McLay
- Earlham Institute, Norwich Research Park, Norwich, Norfolk, UK
| | - L Medcalf
- Animal Health Trust, Kentford, Newmarket, Suffolk, UK
| | - R Newton
- Animal Health Trust, Kentford, Newmarket, Suffolk, UK
| | - A J Davison
- MRC-University of Glasgow Centre for Virus Research, Glasgow, UK
| | - D M Elton
- Animal Health Trust, Kentford, Newmarket, Suffolk, UK
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7
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Tunnicliffe RB, Lockhart-Cairns MP, Levy C, Mould AP, Jowitt TA, Sito H, Baldock C, Sandri-Goldin RM, Golovanov AP. The herpes viral transcription factor ICP4 forms a novel DNA recognition complex. Nucleic Acids Res 2017; 45:8064-8078. [PMID: 28505309 PMCID: PMC5737704 DOI: 10.1093/nar/gkx419] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 05/03/2017] [Indexed: 11/13/2022] Open
Abstract
The transcription factor ICP4 from herpes simplex virus has a central role in regulating the gene expression cascade which controls viral infection. Here we present the crystal structure of the functionally essential ICP4 DNA binding domain in complex with a segment from its own promoter, revealing a novel homo-dimeric fold. We also studied the complex in solution by small angle X-Ray scattering, nuclear magnetic resonance and surface-plasmon resonance which indicated that, in addition to the globular domain, a flanking intrinsically disordered region also recognizes DNA. Together the data provides a rationale for the bi-partite nature of the ICP4 DNA recognition consensus sequence as the globular and disordered regions bind synergistically to adjacent DNA motifs. Therefore in common with its eukaryotic host, the viral transcription factor ICP4 utilizes disordered regions to enhance the affinity and tune the specificity of DNA interactions in tandem with a globular domain.
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Affiliation(s)
- Richard B Tunnicliffe
- Manchester Institute of Biotechnology, School of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester M1 7DN, UK
| | - Michael P Lockhart-Cairns
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PT, UK.,Diamond Light Source, Harwell Science and Innovation Campus, Fermi Ave, Didcot OX11 0QX, UK
| | - Colin Levy
- Manchester Institute of Biotechnology, School of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester M1 7DN, UK
| | - A Paul Mould
- Biomolecular Analysis Core Facility, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PT, UK
| | - Thomas A Jowitt
- Biomolecular Analysis Core Facility, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PT, UK
| | - Hilary Sito
- Manchester Institute of Biotechnology, School of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester M1 7DN, UK
| | - Clair Baldock
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9PT, UK
| | - Rozanne M Sandri-Goldin
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA 92697-4025, USA
| | - Alexander P Golovanov
- Manchester Institute of Biotechnology, School of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester M1 7DN, UK
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8
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Chapa TJ, Du Y, Sun R, Yu D, French AR. Proteomic and phylogenetic coevolution analyses of pM79 and pM92 identify interactions with RNA polymerase II and delineate the murine cytomegalovirus late transcription complex. J Gen Virol 2017; 98:242-250. [PMID: 27926822 DOI: 10.1099/jgv.0.000676] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The regulation of the late viral gene expression in betaherpesviruses is largely undefined. We have previously shown that the murine cytomegalovirus proteins pM79 and pM92 are required for late gene transcription. Here, we provide insight into the mechanism of pM79 and pM92 activity by determining their interaction partners during infection. Co-immunoprecipitation-coupled MS studies demonstrate that pM79 and pM92 interact with an array of cellular and viral proteins involved in transcription. Specifically, we identify RNA polymerase II as a cellular target for both pM79 and pM92. We use inter-protein coevolution analysis to show how pM79 and pM92 likely assemble into a late transcription complex composed of late transcription regulators pM49, pM87 and pM95. Combining proteomic methods with coevolution computational analysis provides novel insights into the relationship between pM79, pM92 and RNA polymerase II and allows the generation of a model of the multi-component viral complex that regulates late gene transcription.
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Affiliation(s)
- Travis J Chapa
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA.,Division of Pediatric Rheumatology, Department of Pediatrics, Washington University School of Medicine, Saint Louis, MO 63110, USA.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Yushen Du
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ren Sun
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Dong Yu
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Anthony R French
- Division of Pediatric Rheumatology, Department of Pediatrics, Washington University School of Medicine, Saint Louis, MO 63110, USA
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9
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Kuddus RH, DeLuca NA. DNA-dependent oligomerization of herpes simplex virus type 1 regulatory protein ICP4. J Virol 2007; 81:9230-7. [PMID: 17581987 PMCID: PMC1951460 DOI: 10.1128/jvi.01054-07] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 06/13/2007] [Indexed: 11/20/2022] Open
Abstract
The human herpes simplex virus type 1 regulatory protein ICP4 binds DNA as a dimer and forms a single protein-DNA complex (A complex) with short DNA probes. ICP4 oligomerized in a DNA-dependent manner, forming two or more protein-DNA complexes with longer DNA fragments containing a single DNA binding site. When resolved electrophoretically, one or more low-mobility DNA-protein complexes follow the fast-moving A complex. The major protein-DNA complex (B complex) formed by ICP4 with long DNA probes migrates just behind the A complex in the electric field, implying the oligomerization of ICP4 on the DNA. Binding experiments with circularly permutated DNA probes containing one ICP4 binding site revealed that about 70 bp of nonspecific DNA downstream of the cognate ICP4 binding site was required for efficient B complex formation. In addition, the C-terminal domain of ICP4 was found to be required for DNA-dependent oligomerization and B complex formation. Gel mobility shift analysis of protein-DNA complexes, combined with supershift analysis using different monoclonal antibodies, indicated that the B complex contained two ICP4 dimers. DNase I footprinting of ICP4-DNA complexes showed that one ICP4 dimer contacts the specific binding site and another ICP4 dimer contacts nonspecific DNA in the B complex. DNA-dependent oligomerization increased the affinity of ICP4 for relatively weak binding sites on large DNA molecules. The results of this study suggest how ICP4 may use multiple weak binding sites to aid in transcription activation.
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Affiliation(s)
- Ruhul H Kuddus
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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10
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Isaac A, Wilcox KW, Taylor JL. SP100B, a repressor of gene expression preferentially binds to DNA with unmethylated CpGs. J Cell Biochem 2006; 98:1106-22. [PMID: 16775843 DOI: 10.1002/jcb.20841] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
SP100A and SP100B are mammalian nuclear proteins encoded by alternatively-spliced transcripts from the SP100 gene. The N-terminal portion of SP100B (aa 1-476) is identical to SP100A and contains an HP1 interaction domain. The C-terminal portion of SP100B (aa 477-688) contains an HMG2 interaction domain and a SAND domain. The SAND domain is a DNA-binding domain identified in several nuclear proteins involved in transcriptional regulation. We have previously reported that SP100B represses expression of genes present on transfected DNA in a SAND domain-dependent manner. The goal of the present study was to characterize the DNA binding properties of full-length SP100B expressed in mammalian cells. SP100B associated with DNA whereas SP100A did not. The SP100B SAND domain was essential for DNA binding. Deletion of the HP1- or HMG2-binding domain had no effect on DNA binding. SP100B preferentially associated with sequences containing CpG dinucleotides. Our results did not reveal any preference of SP100B for bases flanking CpG dinucleotides. The number of CpGs in a DNA sequence and spacing between CpGs influenced SP100B binding, suggesting that multimers of SP100B bind DNA in a cooperative manner. Binding of SP100B was abrogated by methylation of the cytosine residue within the context of the CpG dinucleotide. We propose that the preference of SP100B for non-methylated CpGs provides a mechanism to target SP100B to foreign DNA, including plasmid DNA or viral DNA genomes, most of which are hypomethylated.
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Affiliation(s)
- Anne Isaac
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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11
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Pagamjav O, Sakata T, Matsumura T, Yamaguchi T, Fukushi H. Natural recombinant between equine herpesviruses 1 and 4 in the ICP4 gene. Microbiol Immunol 2005; 49:167-79. [PMID: 15722602 DOI: 10.1111/j.1348-0421.2005.tb03716.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Equine herpesvirus 1 (EHV-1) is a pathogen causing rhinopneumonia in young horses, abortion in mares, and myeloencephalitis in adult horses. Two types, EHV-1 P and EHV-1 B, have recently been dominant among 16 electropherotypes. EHV-1 P and EHV-1 B viruses were compared by long and accurate polymerase chain reaction (LA-PCR) and restriction fragment length polymorphism (RFLP) analysis. Differences in restriction sites were found to be focused in ORF64, which encodes the infected cell protein 4 (ICP4), and downstream of the ICP4 gene. The 3 ' -end and downstream of ICP4 gene of EHV-1 B were found to be replaced by the corresponding region of EHV-4, indicating that EHV-1 B is a naturally occurring recombinant virus between progenitors of EHV-1 P and EHV-4. This is the first report showing a natural interspecies recombinant in alphaherpesviruses.
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Affiliation(s)
- Ochir Pagamjav
- Department of Applied Veterinary Sciences, United Graduate School of Veterinary Sciences, Gifu University, Japan
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12
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Abstract
Mammalian cell nuclei exhibit discrete sites where specific proteins characteristically localize. PML nuclear bodies (PML NBs) (nuclear domain 10s (ND10s)) are the primary localization site for the promyelocytic leukemia (PML) protein and the SP100 autoantigen. The observations that some PML and SP100 isoforms can function as transcriptional regulators, that both the size and number of PML bodies increase in response to interferon treatment, and that many mammalian viruses encode proteins that mediate disruption of PML bodies suggest that these sites suppress viral infection, perhaps by repressing viral gene expression. We hypothesized that a component of PML NBs functions as a repressor of gene expression. To test this hypothesis, we characterized the effect of PML or SP100 isoforms on expression of transfected reporter genes. PML-I, PML-VI, and SP100A did not repress reporter gene expression. In contrast, SP100B repressed reporter gene expression, especially under conditions in which the reporter gene expression was elevated by a viral transactivator or addition of trichostatin A to the culture medium. The SP100B DNA binding domain was required for repression. SP100B had no detectable effect on the amount, methylation pattern, or topological form of plasmid DNA in the nuclei of transfected cells. The demonstrated repressive activity of SP100B supports the hypothesis that SP100B is a component of an innate immune response that represses expression of ectopic DNA.
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Affiliation(s)
- Kent W Wilcox
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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13
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Delhon G, Moraes MP, Lu Z, Afonso CL, Flores EF, Weiblen R, Kutish GF, Rock DL. Genome of bovine herpesvirus 5. J Virol 2003; 77:10339-47. [PMID: 12970418 PMCID: PMC228503 DOI: 10.1128/jvi.77.19.10339-10347.2003] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2003] [Accepted: 07/02/2003] [Indexed: 11/20/2022] Open
Abstract
Here we present the complete genomic sequence of bovine herpesvirus 5 (BHV-5), an alphaherpesvirus responsible for fatal meningoencephalitis in cattle. The 138390-bp genome encodes 70 putative proteins and resembles the alpha2 subgroup of herpesviruses in genomic organization and gene content. BHV-5 is very similar to BHV-1, the etiological agent of infectious bovine rhinotracheitis, as reflected by the high level of amino acid identity in their protein repertoires (average, 82%). The highest similarity to BHV-1 products (>or=95% amino acid identity) is found in proteins involved in viral DNA replication and processing (UL5, UL15, UL29, and UL39) and in virion proteins (UL14, UL19, UL48, and US6). Among the least conserved (
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Affiliation(s)
- G Delhon
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, New York 11944, USA
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14
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Compel P, DeLuca NA. Temperature-dependent conformational changes in herpes simplex virus ICP4 that affect transcription activation. J Virol 2003; 77:3257-68. [PMID: 12584349 PMCID: PMC149779 DOI: 10.1128/jvi.77.5.3257-3268.2003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The C-terminal 500 amino acids of herpes simplex virus type 1 ICP4 are required for full activator function and viral growth and are known to participate in interactions consistent with the role of ICP4 as an activator of transcription. Oligonucleotide mutagenesis was used to target stretches of amino acids that are conserved with the ICP4 analogs of other alphaherpesviruses and were also predicted to be exposed on the surface of the molecule. Seven mutants were isolated that possessed one to three amino acid changes to the residue alanine in four regions between residues 1000 and 1200. The mutants generated were analyzed first in transfection assays and subsequently after introduction into the viral genome. A number of phenotypes representing different degrees of functional impairment were observed. In transient assays conducted at 37 degrees C, mutant M2 was indistinguishable from wild-type ICP4. Mutants M6 and M7 were marginally impaired. M3, M4, and M5 were more significantly impaired but still able to activate transcription, and M1 was completely impaired. In the context of the viral genome, M1, M3, and M7 were found to be temperature sensitive for growth. All three overproduced immediate-early (IE) proteins at the nonpermissive temperature (NPT). M3 and M7 produced early but not late proteins, and M1 produced neither early nor late proteins, at the NPT. The ICP4 proteins synthesized by all of the mutants tested were able to bind to specific ICP4 binding sites in electrophoretic mobility shift experiments. However, the DNA-protein complexes formed with the ICP4 from M1, M3, or M7 produced at the NPT possessed altered mobility. These complexes were not supershifted by a monoclonal antibody that recognizes an epitope in the C terminus; however, they were supershifted by a monoclonal antibody that recognizes the N terminus. The results suggest that the mutant forms of ICP4, while able to bind to DNA, are conformationally altered at the NPT, thus impairing the ability of the protein to activate transcription to different extents. The complete lack of ICP4 function characteristic of the M1 protein, and the inability of all the mutants to attenuate IE gene expression, suggest that the mutations additionally affect functions of the N terminus to different extents.
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Affiliation(s)
- Peter Compel
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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Ou CJ, Wong ML, Huang C, Chang TJ. Suppression of promoter activity of the LAT gene by IE180 of pseudorabies virus. Virus Genes 2002; 25:227-39. [PMID: 12881635 DOI: 10.1023/a:1020959521745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The latency-associated transcript (LAT) gene is the only viral genomic region that is abundantly transcribed during pseudorabies virus (PrV) latent infection. The mechanism of reactivation of PrV from latency remains unknown. To analyze the regulation mechanism of the LAT promoter, we constructed a series of recombinant vectors in which various sequences upstream of LAT were linked to the chloramphenicol acetyltransferase (CAT) gene. Transcriptional efficiency was examined by cotransfection with plasmids carrying the PrV IE, EP0, or gD gene, respectively. Results showed that the activity of PrV LAT promoter was dramatically repressed by the IE180 protein and a TATA box and a putative IE180 binding site within the promoter were involved in this repression. To dissect the functional domains of IE180, we compared the relative repressive abilities of IE180 variants to the LAT promoter by transient transfection assays. Mutational analysis demonstrated that almost the whole IE180 (amino acid residues 1-1440) are essential for its repression to LAT promoter. To explore the possible mechanism of repression, an electrophoretic mobility shift assay (EMSA) using nuclear extracts from neuronal cells was performed and formation of protein-DNA complexes between IE180 and the oligonucleotide probe (-46 to -19, relative to the start site of LAT transcription) was demonstrated. The association of IE180 with the region encompassing the putative IE180 binding site and the TATA box upstream of PrV LAT gene was further confirmed by supershift of EMSA complexes using IE180 specific antibody. Thus, our results suggested that IE180 repressed the LAT promoter via an interaction between IE180, LAT promoter and cellular protein(s).
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Affiliation(s)
- Chia-Jen Ou
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung 402, Taiwan, ROC
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