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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] [Key Words] [MESH Headings] [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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Affiliation(s)
- Tong Zhou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China.
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China.
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Xin-Xin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Xuming Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Yanling Yu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, Sichuan, China
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2
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Frasson I, Soldà P, Nadai M, Lago S, Richter SN. Parallel G-quadruplexes recruit the HSV-1 transcription factor ICP4 to promote viral transcription in herpes virus-infected human cells. Commun Biol 2021; 4:510. [PMID: 33931711 PMCID: PMC8087788 DOI: 10.1038/s42003-021-02035-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 03/26/2021] [Indexed: 02/03/2023] Open
Abstract
G-quadruplexes (G4s) are four-stranded nucleic acid structures abundant at gene promoters. They can adopt several distinctive conformations. G4s have been shown to form in the herpes simplex virus-1 (HSV-1) genome during its viral cycle. Here by cross-linking/pull-down assay we identified ICP4, the major HSV-1 transcription factor, as the protein that most efficiently interacts with viral G4s during infection. ICP4 specific and direct binding and unfolding of parallel G4s, including those present in HSV-1 immediate early gene promoters, induced transcription in vitro and in infected cells. This mechanism was also exploited by ICP4 to promote its own transcription. Proximity ligation assay allowed visualization of G4-protein interaction at the single selected G4 in cells. G4 ligands inhibited ICP4 binding to G4s. Our results indicate the existence of a well-defined G4-viral protein network that regulates the productive HSV-1 cycle. They also point to G4s as elements that recruit transcription factors to activate transcription in cells.
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Affiliation(s)
- Ilaria Frasson
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Paola Soldà
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Matteo Nadai
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Sara Lago
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Sara N Richter
- Department of Molecular Medicine, University of Padua, Padua, Italy.
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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: 19] [Impact Index Per Article: 2.7] [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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Kulej K, Avgousti DC, Sidoli S, Herrmann C, Della Fera AN, Kim ET, Garcia BA, Weitzman MD. Time-resolved Global and Chromatin Proteomics during Herpes Simplex Virus Type 1 (HSV-1) Infection. Mol Cell Proteomics 2017; 16:S92-S107. [PMID: 28179408 DOI: 10.1074/mcp.m116.065987] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/03/2017] [Indexed: 11/06/2022] Open
Abstract
Herpes simplex virus (HSV-1) lytic infection results in global changes to the host cell proteome and the proteins associated with host chromatin. We present a system level characterization of proteome dynamics during infection by performing a multi-dimensional analysis during HSV-1 lytic infection of human foreskin fibroblast (HFF) cells. Our study includes identification and quantification of the host and viral proteomes, phosphoproteomes, chromatin bound proteomes and post-translational modifications (PTMs) on cellular histones during infection. We analyzed proteomes across six time points of virus infection (0, 3, 6, 9, 12 and 15 h post-infection) and clustered trends in abundance using fuzzy c-means. Globally, we accurately quantified more than 4000 proteins, 200 differently modified histone peptides and 9000 phosphorylation sites on cellular proteins. In addition, we identified 67 viral proteins and quantified 571 phosphorylation events (465 with high confidence site localization) on viral proteins, which is currently the most comprehensive map of HSV-1 phosphoproteome. We investigated chromatin bound proteins by proteomic analysis of the high-salt chromatin fraction and identified 510 proteins that were significantly different in abundance during infection. We found 53 histone marks significantly regulated during virus infection, including a steady increase of histone H3 acetylation (H3K9ac and H3K14ac). Our data provide a resource of unprecedented depth for human and viral proteome dynamics during infection. Collectively, our results indicate that the proteome composition of the chromatin of HFF cells is highly affected during HSV-1 infection, and that phosphorylation events are abundant on viral proteins. We propose that our epi-proteomics approach will prove to be important in the characterization of other model infectious systems that involve changes to chromatin composition.
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Affiliation(s)
- Katarzyna Kulej
- From the ‡Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.,§Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Daphne C Avgousti
- From the ‡Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.,§Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Simone Sidoli
- ¶Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.,‖Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Christin Herrmann
- §Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,**Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Ashley N Della Fera
- §Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Eui Tae Kim
- From the ‡Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.,§Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Benjamin A Garcia
- ¶Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; .,‖Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Matthew D Weitzman
- From the ‡Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; .,§Division of Cancer Pathobiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
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5
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Wang X, Diao C, Yang X, Yang Z, Liu M, Li X, Tang H. ICP4-induced miR-101 attenuates HSV-1 replication. Sci Rep 2016; 6:23205. [PMID: 26984403 PMCID: PMC4794718 DOI: 10.1038/srep23205] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/25/2016] [Indexed: 11/09/2022] Open
Abstract
Hepes simplex Virus type 1 (HSV-1) is an enveloped DNA virus that can cause lytic and latent infection. miRNAs post-transcriptionally regulate gene expression, and our previous work has indicated that HSV-1 infection induces miR-101 expression in HeLa cells. The present study demonstrates that HSV-1-induced miR-101 is mainly derived from its precursor hsa-mir-101-2, and the HSV-1 immediate early gene ICP4 (infected-cell polypeptide 4) directly binds to the hsa-mir-101-2 promoter to activate its expression. RNA-binding protein G-rich sequence factor 1 (GRSF1) was identified as a new target of miR-101; GRSF1 binds to HSV-1 p40 mRNA and enhances its expression, facilitating viral proliferation. Together, ICP4 induces miR-101 expression, which downregulates GRSF1 expression and attenuates the replication of HSV-1. This allows host cells to maintain a permissive environment for viral replication by preventing lytic cell death. These findings indicate that HSV-1 early gene expression modulates host miRNAs to regulate molecular defense mechanisms. This study provides novel insight into host-virus interactions in HSV-1 infection and may contribute to the development of antiviral therapeutics.
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Affiliation(s)
- Xiangling Wang
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
| | - Caifeng Diao
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
| | - Xi Yang
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
| | - Zhen Yang
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
| | - Min Liu
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
| | - Xin Li
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
| | - Hua Tang
- Tianjin Life Science Research Center and Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, 22 Qi-Xiang-Tai Road, Tianjin 300070, China
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Functional Characterization of the Serine-Rich Tract of Varicella-Zoster Virus IE62. J Virol 2015; 90:959-71. [PMID: 26537679 DOI: 10.1128/jvi.02096-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/27/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The immediate early 62 protein (IE62) of varicella-zoster virus (VZV), a major viral trans-activator, initiates the virus life cycle and is a key component of pathogenesis. The IE62 possesses several domains essential for trans-activation, including an acidic trans-activation domain (TAD), a serine-rich tract (SRT), and binding domains for USF, TFIIB, and TATA box binding protein (TBP). Transient-transfection assays showed that the VZV IE62 lacking the SRT trans-activated the early VZV ORF61 promoter at only 16% of the level of the full-length IE62. When the SRT of IE62 was replaced with the SRT of equine herpesvirus 1 (EHV-1) IEP, its trans-activation activity was completely restored. Herpes simplex virus 1 (HSV-1) ICP4 that lacks a TAD very weakly (1.5-fold) trans-activated the ORF61 promoter. An IE62 TAD-ICP4 chimeric protein exhibited trans-activation ability (10.2-fold), indicating that the IE62 TAD functions with the SRT of HSV-1 ICP4 to trans-activate viral promoters. When the serine and acidic residues of the SRT were replaced with Ala, Leu, and Gly, trans-activation activities of the modified IE62 proteins IE62-SRTΔSe and IE62-SRTΔAc were reduced to 46% and 29% of wild-type activity, respectively. Bimolecular complementation assays showed that the TAD of IE62, EHV-1 IEP, and HSV-1 VP16 interacted with Mediator 25 in human melanoma MeWo cells. The SRT of IE62 interacted with the nucleolar-ribosomal protein EAP, which resulted in the formation of globular structures within the nucleus. These results suggest that the SRT plays an important role in VZV viral gene expression and replication. IMPORTANCE The immediate early 62 protein (IE62) of varicella-zoster virus (VZV) is a major viral trans-activator and is essential for viral growth. Our data show that the serine-rich tract (SRT) of VZV IE62, which is well conserved within the alphaherpesviruses, is needed for trans-activation mediated by the acidic trans-activation domain (TAD). The TADs of IE62, EHV-1 IEP, and HSV-1 VP16 interacted with cellular Mediator 25 in bimolecular complementation assays. The interaction of the IE62 SRT with nucleolar-ribosomal protein EAP resulted in the formation of globular structures within the nucleus. Understanding the mechanisms by which the TAD and SRT of IE62 contribute to the function of this essential regulatory protein is important in understanding the gene program of this human pathogen.
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Uversky VN. The intrinsic disorder alphabet. III. Dual personality of serine. INTRINSICALLY DISORDERED PROTEINS 2015; 3:e1027032. [PMID: 28232888 DOI: 10.1080/21690707.2015.1027032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 02/16/2015] [Accepted: 03/02/2015] [Indexed: 12/23/2022]
Abstract
Proteins are natural polypeptides consisting of 20 major amino acid residues, content and order of which in a given amino acid sequence defines the ability of a related protein to fold into unique functional state or to stay intrinsically disordered. Amino acid sequences code for both foldable (ordered) proteins/domains and for intrinsically disordered proteins (IDPs) and IDP regions (IDPRs), but these sequence codes are dramatically different. This difference starts with a very general property of the corresponding amino acid sequences, namely, their compositions. IDPs/IDPRs are enriched in specific disorder-promoting residues, whereas amino acid sequences of ordered proteins/domains typically contain more order-promoting residues. Therefore, the relative abundances of various amino acids in ordered and disordered proteins can be used to scale amino acids according to their disorder promoting potentials. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and represents serine, which is the third most disorder-promoting residue. Similar to previous publications, this review represents some physico-chemical properties of serine and the roles of this residue in structures and functions of ordered proteins, describes major posttranslational modifications tailored to serine, and finally gives an overview of roles of serine in structure and functions of intrinsically disordered proteins.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer Research Institute; Morsani College of Medicine, University of South Florida; Tampa, FL USA; Biology Department; Faculty of Science, King Abdulaziz University; Jeddah, Kingdom of Saudi Arabia; Institute for Biological Instrumentation, Russian Academy of Sciences; Pushchino, Moscow Region, Russia; Laboratory of Structural Dynamics, Stability and Folding of Proteins; Institute of Cytology, Russian Academy of Sciences; St. Petersburg, Russia
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8
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Wuest T, Zheng M, Efstathiou S, Halford WP, Carr DJJ. The herpes simplex virus-1 transactivator infected cell protein-4 drives VEGF-A dependent neovascularization. PLoS Pathog 2011; 7:e1002278. [PMID: 21998580 PMCID: PMC3188529 DOI: 10.1371/journal.ppat.1002278] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 08/02/2011] [Indexed: 01/08/2023] Open
Abstract
Herpes simplex virus-1 (HSV-1) causes lifelong infection affecting between 50 and 90% of the global population. In addition to causing dermal lesions, HSV-1 is a leading cause of blindness resulting from recurrent corneal infection. Corneal disease is characterized by loss of corneal immunologic privilege and extensive neovascularization driven by vascular endothelial growth factor-A (VEGF-A). In the current study, we identify HSV-1 infected cells as the dominant source of VEGF-A during acute infection, and VEGF-A transcription did not require TLR signaling or MAP kinase activation. Rather than being an innate response to the pathogen, VEGF-A transcription was directly activated by the HSV-1 encoded immediate early transcription factor, ICP4. ICP4 bound the proximal human VEGF-A promoter and was sufficient to promote transcription. Transcriptional activation also required cis GC-box elements common to the VEGF-A promoter and HSV-1 early genes. Our results suggest that the neovascularization characteristic of ocular HSV-1 disease is a direct result of HSV-1's major transcriptional regulator, ICP4, and similarities between the VEGF-A promoter and those of HSV-1 early genes. Herpes simplex virus-type 1 is the leading cause of infectious corneal blindness in the industrialized world. Most of the morbidity associated with the virus is due to the host response to episodic reactivation of latent virus. Corneal immunologic privilege is associated with a number of factors including the absence of blood and lymphatic vessels. Conversely, corneal hem (blood)- and lymph-angiogenesis driven by inflammation correlate with the loss of privilege. Neovascularization is a common phenomenon in HSV-1 keratitis that correlates with poor prognosis. We have previously discovered HSV-1 elicits corneal lymphangiogenesis through a unique mechanism involving vascular endothelial growth factor (VEGF)-A independent of that described for other insults including transplantation or bacterial infection. However, the viral-encoded product(s) that elicit host production of VEGF-A is(are) unknown. In this paper, we have identified infected cell protein-4 (ICP4) as the primary virus-encoded product that drives VEGF-A expression. As VEGF-A is involved in driving neovascularization associated with tumor growth and metastasis, proteins that influence transcriptional regulation of VEGF-A may be useful in the development of adjunct therapy for such disparate diseases as cancer and HSV-1 keratitis.
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MESH Headings
- Animals
- Cell Line
- Eye/pathology
- Eye/virology
- Herpesvirus 1, Human/genetics
- Herpesvirus 1, Human/metabolism
- Herpesvirus 1, Human/pathogenicity
- Humans
- Immediate-Early Proteins/genetics
- Immediate-Early Proteins/metabolism
- Keratitis, Herpetic/pathology
- Keratitis, Herpetic/virology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Fluorescence/methods
- Neovascularization, Pathologic/genetics
- Plasmids
- Promoter Regions, Genetic
- Real-Time Polymerase Chain Reaction
- Sequence Analysis, DNA
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcriptional Activation
- Vascular Endothelial Growth Factor A/genetics
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Todd Wuest
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Min Zheng
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Stacey Efstathiou
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - William P. Halford
- Department of Microbiology and Immunology, Southern Illinois University School of Medicine, Springfield, Illinois, United States of America
| | - Daniel J. J. Carr
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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9
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Chien KY, Liu HC, Goshe MB. Development and application of a phosphoproteomic method using electrostatic repulsion-hydrophilic interaction chromatography (ERLIC), IMAC, and LC-MS/MS analysis to study Marek's Disease Virus infection. J Proteome Res 2011; 10:4041-53. [PMID: 21736374 DOI: 10.1021/pr2002403] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Marek's Disease (MD) is an avian neoplastic disease caused by Marek's Disease Virus (MDV). The mechanism of virus transition between the lytic and latent cycle is still being investigated; however, post-translational modifications, especially phosphorylation, have been thought to play an important role. Previously, our group has used strong cation exchange chromatography in conjunction with reversed-phase liquid chromatography-tandem mass spectrometry (LC-MS/MS) to study the changes in global proteomic expression upon MDV infection (Ramaroson , M. F.; Ruby, J.; Goshe, M. B.; Liu , H.-C. S. J. Proteome Res. 2008, 7, 4346-4358). Here, we extend our study by developing an effective separation and enrichment approach to investigate the changes occurring in the phosphoproteome using electrostatic repulsion-hydrophilic interaction chromatography (ERLIC) to fractionate peptides from chicken embryo fibroblast (CEF) digests and incorporating a subsequent IMAC enrichment step to selectively target phosphorylated peptides for LC-MS/MS analysis. To monitor the multidimensional separation between mock- and MDV-infected CEF samples, a casein phosphopeptide mixture was used as an internal standard. With LC-MS/MS analysis alone, no CEF phosphopeptides were detected, while with ERLIC fractionation only 1.2% of all identified peptides were phosphorylated. However, the incorporation of IMAC enrichment with ERLIC fractionation provided a 50-fold increase in the percentage of identified phosphopeptides. Overall, a total of 581 unique phosphopeptides were identified (p < 0.05) with those of the MDV-infected CEF sample containing nearly twice as many as the mock-infected control of which 11% were unique to MDV proteins. The changes in the phosphoproteome are discussed including the role that microtubule-associated proteins may play in MDV infection mechanisms.
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Affiliation(s)
- Ko-Yi Chien
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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10
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Schwartz D, Church GM. Collection and Motif-Based Prediction of Phosphorylation Sites in Human Viruses. Sci Signal 2010; 3:rs2. [DOI: 10.1126/scisignal.2001099] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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11
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Cyclin-dependent kinase 1/cyclin B1 phosphorylates varicella-zoster virus IE62 and is incorporated into virions. J Virol 2008; 82:12116-25. [PMID: 18799590 DOI: 10.1128/jvi.00153-08] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Varicella-zoster virus (VZV), an alphaherpesvirus restricted to humans, infects differentiated cells in vivo, including T lymphocytes, keratinocytes, and neurons, and spreads rapidly in confluent cultured dermal fibroblasts (HFFs). In VZV-infected HFFs, atypical expression of cyclins D3 and B1 occurs along with the induction of cyclin-dependent kinase (CDK) activity. A specific CDK1 inhibitor blocked VZV spread, indicating an important function for this cellular kinase in VZV replication. CDK activity assays of infected cells revealed a large viral phosphoprotein that was identified as being the major immediate-early transactivator, IE62. Since IE62 colocalized with CDK1/cyclin B1 by confocal microscopy, we investigated whether this cellular kinase complex interacts with IE62. Using recombinant fragments of IE62 spanning the entire amino acid sequence, we found that purified CDK1/cyclin B1 phosphorylated IE62 at residues T10, S245, and T680 in vitro. Immunoprecipitation of cyclin B1 from VZV-infected HFFs indicated that IE62 was included in the complex within infected cells. The full-length IE62 protein, obtained by immunoprecipitation from infected cells, was also phosphorylated by purified CDK1/cyclin B1. Based on IE62/CDK1/cyclin B1 colocalization near viral assembly regions, we hypothesized that these cellular proteins could be incorporated into VZV virions with IE62. Purified virions were analyzed by immunoblotting for the presence of CDK1 and cyclin B1, and active CDK1 and cyclin B1 were present in the VZV tegument with IE62 and were sensitive to detergent treatment. Thus, IE62 is a substrate for CDK1/cyclin B1, and virions could deliver the active cellular kinase to nondividing cells that normally do not express it.
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12
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Johnson KE, Song B, Knipe DM. Role for herpes simplex virus 1 ICP27 in the inhibition of type I interferon signaling. Virology 2008; 374:487-94. [PMID: 18279905 DOI: 10.1016/j.virol.2008.01.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 12/14/2007] [Accepted: 01/02/2008] [Indexed: 10/22/2022]
Abstract
Host cells respond to viral infection by many mechanisms, including the production of type I interferons which act in a paracrine and autocrine manner to induce the expression of antiviral interferon-stimulated genes (ISGs). Viruses have evolved means to inhibit interferon signaling to avoid induction of the innate immune response. Herpes simplex virus 1 (HSV-1) has several mechanisms to inhibit type I interferon production, the activities of ISGs, and the interferon signaling pathway itself. We report that the inhibition of the Jak/STAT pathway by HSV-1 requires viral gene expression and that viral immediate-early protein ICP27 plays a role in downregulating STAT-1 phosphorylation and in preventing the accumulation of STAT-1 in the nucleus. We also show that expression of ICP27 by transfection causes an inhibition of IFN-induced STAT-1 nuclear accumulation. Therefore, ICP27 is necessary and sufficient for at least some of the effects of HSV infection on STAT-1.
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Affiliation(s)
- Karen E Johnson
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston 02115, USA
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13
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Herpes simplex virus type 1 immediate-early protein ICP27 is required for efficient incorporation of ICP0 and ICP4 into virions. J Virol 2007; 82:268-77. [PMID: 17959681 DOI: 10.1128/jvi.01588-07] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Early in infection, herpes simplex virus type 1 (HSV-1) immediate-early (IE) proteins ICP0 and ICP4 localize to the nucleus, where they stimulate viral transcription. Later in infection, ICP0 and to a lesser extent ICP4 accumulate in the cytoplasm, but their biological role there is unknown. Previously, it was shown that the cytoplasmic localization of ICP0/4 requires the multifunctional IE protein ICP27, which is itself an activator of viral gene expression. Here, we identify a viral ICP27 mutant, d3-4, which is unable to efficiently localize ICP0 and ICP4 to the cytoplasm but which otherwise resembles wild-type HSV-1 in its growth and viral gene expression phenotypes. These results genetically separate the function of ICP27 that affects ICP0/4 localization from its other functions, which affect viral growth and gene expression. As both ICP0 and ICP4 are known to be minor virion components, we used d3-4 to test the hypothesis that the cytoplasmic localization of these proteins is required for their incorporation into viral particles. Consistent with this conjecture, d3-4 virions were found to lack ICP0 in their tegument and to have greatly reduced levels of ICP4. Thus, the cytoplasmic localization of ICP0 and ICP4 appears to be a prerequisite for the assembly of these important transcriptional regulatory proteins into viral particles. Furthermore, our results show that ICP27 plays a previously unrecognized role in determining the composition of HSV-1 virions.
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14
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Petrik DT, Schmitt KP, Stinski MF. The autoregulatory and transactivating functions of the human cytomegalovirus IE86 protein use independent mechanisms for promoter binding. J Virol 2007; 81:5807-18. [PMID: 17376893 PMCID: PMC1900308 DOI: 10.1128/jvi.02437-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The functions of the human cytomegalovirus (HCMV) IE86 protein are paradoxical, as it can both activate and repress viral gene expression through interaction with the promoter region. Although the mechanism for these functions is not clearly defined, it appears that a combination of direct DNA binding and protein-protein interactions is involved. Multiple sequence alignment of several HCMV IE86 homologs reveals that the amino acids (534)LPIYE(538) are conserved between all primate and nonprimate CMVs. In the context of a bacterial artificial chromosome (BAC), mutation of both P535 and Y537 to alanines (P535A/Y537A) results in a nonviable BAC. The defective HCMV BAC does not undergo DNA replication, although the P535A/Y537A mutant IE86 protein appears to be stably expressed. The P535A/Y537A mutant IE86 protein is able to negatively autoregulate transcription from the major immediate-early (MIE) promoter and was recruited to the MIE promoter in a chromatin immunoprecipitation (ChIP) assay. However, the P535A/Y537A mutant IE86 protein was unable to transactivate early viral genes and was not recruited to the early viral UL4 and UL112 promoters in a ChIP assay. From these data, we conclude that the transactivation and repressive functions of the HCMV IE86 protein can be separated and must occur through independent mechanisms.
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Affiliation(s)
- Dustin T Petrik
- Interdisciplinary Program in Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA
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15
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Buczynski KA, Kim SK, O'Callaghan DJ. Initial characterization of 17 viruses harboring mutant forms of the immediate-early gene of equine herpesvirus 1. Virus Genes 2006; 31:229-39. [PMID: 16025249 DOI: 10.1007/s11262-005-1801-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Accepted: 03/23/2005] [Indexed: 10/25/2022]
Abstract
The sole immediate-early (IE) gene of equine herpesvirus 1 (EHV-1) encodes a major regulatory protein of 1487 amino acids (aa) capable of modulating gene expression from both early and late promoters and also of trans-repressing its own promoter. Using a specially designed recombination system and a library of IE linker-insertion, deletion, point, and nonsense mutant constructs that encode forms of the IE protein (IEP) harboring mutations within all five regions, 17 mutant viruses were generated and characterized. Ribonuclease protection analyses revealed that all 17 mutants synthesize the IE mRNA in RK-13 cells, whereas those that failed to replicate on non-complementing RK-13 cells displayed a defect in the transcription of either an important early gene (EICP0) and/or an essential late gene (glycoprotein D). Western blot analyses showed that the IEP was synthesized and detectable in cells infected with each mutant virus, including those mutants that failed to replicate on non-complementing RK-13 cells. Eleven of the 17 mutants were capable of growth on non-complementing RK-13 cells, whereas mutant viruses with deletions within the serine-rich tract (SRT), nucleus localization signal (NLS), or DNA-binding domain (DBD) were capable of growth only on the IEP-producing cell line (IE13.1). Lastly, temperature shift experiments revealed that mutant viruses containing deletions within the C-terminus (KyAn1029 and KyAn1411) or within the SRT (KyADeltaSRT2) of the IEP exhibited a temperature-sensitive phenotype in that these viruses, in contrast to the parent KyA, failed to replicate at 39 degrees C. Overall, these results indicate that the C-terminus of the IEP is not essential for IEP function in cell culture, but this region contains elements that enhance the function(s) of the IEP. The initial characterization of these 17 EHV-1 mutants has shown that sequences totaling at least 43% of the IEP are not essential for virus replication in cell culture.
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Affiliation(s)
- Kimberly A Buczynski
- Department of Microbiology and Immunology, and Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, Louisiana 71130, USA
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16
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Eisfeld AJ, Turse SE, Jackson SA, Lerner EC, Kinchington PR. Phosphorylation of the varicella-zoster virus (VZV) major transcriptional regulatory protein IE62 by the VZV open reading frame 66 protein kinase. J Virol 2006; 80:1710-23. [PMID: 16439528 PMCID: PMC1367140 DOI: 10.1128/jvi.80.4.1710-1723.2006] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
IE62, the major transcriptional regulatory protein encoded by varicella-zoster virus (VZV), is nuclear at early times of VZV infection but then becomes predominantly cytoplasmic as a result of expression of the protein kinase encoded by open reading frame 66 (ORF66). Cytoplasmic forms of IE62 are required for its inclusion as an abundant VZV virion tegument protein. Here we show that ORF66 directly phosphorylates IE62 at two residues, with phosphorylation at S686 being sufficient to regulate IE62 nuclear import. Phosphotryptic peptide analyses established an ORF66 kinase-mediated phosphorylation of the complete IE62 protein in transfected and VZV-infected cells. Using truncated and point-mutated IE62 peptides, ORF66-directed phosphorylation was mapped to residues S686 and S722, immediately downstream of the IE62 nuclear localization signal. An IE62 protein with an S686A mutation retained efficient nuclear import activity, even in the presence of functional ORF66 protein kinase, but an IE62 protein containing an S686D alteration was imported into the nucleus inefficiently. In contrast, the nuclear import of IE62 carrying an S722A mutation was still modulated by ORF66 expression, and IE62 with an S722D mutation was imported efficiently into the nucleus. An in vitro phosphorylation assay was developed using bacterially expressed IE62-maltose binding protein fusions as substrates for immunopurified ORF66 protein kinase from recombinant baculovirus-infected insect cells. ORF66 kinase phosphorylated the IE62 peptides, with similar specificities for residues S686 and S722. These results indicate that IE62 nuclear import is modulated as a result of direct phosphorylation of IE62 by ORF66 kinase. This represents an interaction that is, so far, unique among the alphaherpesviruses.
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Affiliation(s)
- Amie J Eisfeld
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA
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17
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Olesky M, McNamee EE, Zhou C, Taylor TJ, Knipe DM. Evidence for a direct interaction between HSV-1 ICP27 and ICP8 proteins. Virology 2005; 331:94-105. [PMID: 15582656 DOI: 10.1016/j.virol.2004.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Revised: 09/13/2004] [Accepted: 10/05/2004] [Indexed: 11/30/2022]
Abstract
Herpes simplex virus 1 (HSV-1) ICP27 and ICP8 proteins have both been implicated in the transcription of late genes and regulation of viral gene expression. We showed previously that ICP27 and ICP8 associate with the RNAP II holoenzyme (Zhou and Knipe, J. Virol. 76, 5893-5904). Here, we demonstrate that ICP27 and ICP8 coprecipitate from lysates of HSV-1-infected HEp2 cells and from lysates of insect cells expressing ICP27 and ICP8, the latter being in the absence of other HSV-1 proteins. By expressing and purifying hexahistidine-tagged ICP8 (His-ICP8) and maltose binding protein (MBP)-tagged ICP27 (MBP-27) proteins and performing in vitro immunoprecipitation and pull-down assays, we also demonstrate that ICP27 and ICP8 coprecipitate in the absence of other viral or cellular proteins. Taken together, these data provide evidence that ICP27 and ICP8 interact directly in vitro and in infected cells. We hypothesize that the ICP27-ICP8 interaction plays a role in the stimulation of late gene transcription.
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Affiliation(s)
- Melanie Olesky
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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18
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Advani SJ, Durand LO, Weichselbaum RR, Roizman B. Oct-1 is posttranslationally modified and exhibits reduced capacity to bind cognate sites at late times after infection with herpes simplex virus 1. J Virol 2003; 77:11927-32. [PMID: 14581529 PMCID: PMC254286 DOI: 10.1128/jvi.77.22.11927-11932.2003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In herpes simplex virus 1-infected cells, a high level of alpha gene expression requires the transactivation of the genes by a complex containing the viral alpha transinducing factor (alphaTIF) and two cellular proteins. The latter two, HCF-1 and octamer binding protein Oct-1, are transcriptional factors regulated in a cell cycle-dependent manner. alphaTIF is a protein made late in infection but packaged with the virion to transactivate viral genes in newly infected cells. In light of the accumulation of large amounts of alphaTIF, the absence of alpha gene expression late in infection suggested the possibility that one or more transcriptional factors required for alpha gene expression is modified late in infection. Here we report that Oct-1 is posttranscriptionally modified late in infection, that the modification is mediated by the virus but does not involve viral protein kinases or cdc2 kinase activated by the virus late in infection, and that the modified Oct-1 has a reduced affinity for its cognate DNA site. These results are consistent with the hypothesis that modification of Oct-1 transcriptional factor could account at least in part for the shutoff of alpha gene expression late in infection.
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Affiliation(s)
- Sunil J Advani
- The Marjorie B. Kovler Viral Oncology Laboratories, The University of Chicago, Chicago, Illinois 60637, USA
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19
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Kim DB, DeLuca NA. Phosphorylation of transcription factor Sp1 during herpes simplex virus type 1 infection. J Virol 2002; 76:6473-9. [PMID: 12050359 PMCID: PMC136260 DOI: 10.1128/jvi.76.13.6473-6479.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2002] [Accepted: 04/08/2002] [Indexed: 11/20/2022] Open
Abstract
The expression of most herpes simplex virus type 1 (HSV-1) immediate-early (IE) and early (E) genes decreases late in productive infection. IE and E promoters contain various binding sites for cellular activators, including sites for Sp1, upstream of the TATA box, while late gene promoters generally lack such sites. To address the possibility that Sp1 function may be altered during the course of infection, the modification state and activity of Sp1 were investigated as a function of infection. Sp1 was quantitatively phosphorylated in HSV-1-infected cells without a significant change in abundance. The kinetics of accumulation of phosphorylated Sp1 immediately preceded the decline in E gene (thymidine kinase gene [tk]) mRNA abundance. Phosphorylation of Sp1 required ICP4; however, the proportion of phosphorylated Sp1 was reduced during infection in the presence of phosphonoacetic acid or in the absence of ICP27. While the DNA binding activity of Sp1 was not greatly affected by phosphorylation, the ability of phosphorylated Sp1 isolated from HSV-infected cells to activate transcription in vitro was decreased. These studies suggest that modification of Sp1 may contribute to the decrease of IE and E gene expression late in infection.
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Affiliation(s)
- Dool-Bboon Kim
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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20
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Zhou C, Knipe DM. Association of herpes simplex virus type 1 ICP8 and ICP27 proteins with cellular RNA polymerase II holoenzyme. J Virol 2002; 76:5893-904. [PMID: 12021322 PMCID: PMC136207 DOI: 10.1128/jvi.76.12.5893-5904.2002] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) infection causes the shutoff of host gene transcription and the induction of a transcriptional program of viral gene expression. Cellular RNA polymerase II is responsible for transcription of all the viral genes, but several viral proteins stimulate viral gene transcription. ICP4 is required for all delayed-early and late gene transcription, ICP0 stimulates transcription of viral genes, and ICP27 stimulates expression of some early genes and transcription of at least some late viral genes. The early DNA-binding protein, ICP8, also stimulates late gene transcription. We therefore investigated which HSV proteins interact with RNA polymerase II. Using immunoprecipitation and Western blotting methods, we observed the coprecipitation of ICP27 and ICP8 with RNA polymerase II holoenzyme. The association of ICP27 with RNA polymerase II was detectable as early as 3 h postinfection, while ICP8 association became evident by 5 h postinfection, and the association of both was independent of viral DNA synthesis. Infections with ICP27 gene mutant viruses revealed that ICP27 is required for the association of ICP8 with RNA polymerase II, while studies with ICP8 gene deletion mutants showed no apparent role for ICP8 in the association of ICP27 with RNA polymerase II. The association of ICP27 and ICP8 with RNA polymerase II holoenzyme appeared to be independent of nucleic acids. We hypothesize that the interaction of ICP27 with RNA polymerase II holoenzyme reflects its role in stimulating early and late gene expression and/or its role in inhibiting host transcription and that the interaction of ICP8 with RNA polymerase II holoenzyme reflects its role in stimulating late gene transcription.
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Affiliation(s)
- Changhong Zhou
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts, USA
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21
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Advani SJ, Hagglund R, Weichselbaum RR, Roizman B. Posttranslational processing of infected cell proteins 0 and 4 of herpes simplex virus 1 is sequential and reflects the subcellular compartment in which the proteins localize. J Virol 2001; 75:7904-12. [PMID: 11483735 PMCID: PMC115034 DOI: 10.1128/jvi.75.17.7904-7912.2001] [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: 12/31/2022] Open
Abstract
The herpes simplex virus 1 (HSV-1) infected cell proteins 0 and 4 (ICP0 and ICP4) are multifunctional proteins extensively posttranscriptionally processed by both cellular and viral enzymes. We examined by two-dimensional separations the posttranslational forms of ICP0 and ICP4 in HEp-2 cells and in human embryonic lung (HEL) fibroblasts infected with wild-type virus, mutant R325, lacking the sequences encoding the U(S)1.5 protein and the overlapping carboxyl-terminal domain of ICP22, or R7914, in which the aspartic acid 199 of ICP0 was replaced by alanine. We report the following (i) Both ICP0 and ICP4 were sequentially posttranslationally modified at least until 12 h after infection. In HEL fibroblasts, the processing of ICP0 shifted from A+B forms at 4 h to D+G forms at 8 h and finally to G, E, and F forms at 12 h. The ICP4 progression was from the A' form noted at 2 h to B' and C' forms noted at 4 h to the additional D' and E' forms noted at 12 h. The progression tended to be toward more highly charged forms of the proteins. (ii) Although the overall patterns were similar, the mobility of proteins made in HEp-2 cells differed from those made in HEL fibroblasts. (iii) The processing of ICP0 forms E and F was blocked in HEL fibroblasts infected with R325 or with wild-type virus and treated with roscovitine, a specific inhibitor of cell cycle-dependent kinases cdc2, cdk2, and cdk5. R325-infected HEp-2 cells lacked the D' form of ICP4, and roscovitine blocked the appearance of the most highly charged E' form of ICP4. (iv) A characteristic of ICP0 is that it is translocated into the cytoplasm of HEL fibroblasts between 5 and 9 h after infection. Addition of MG132 to the cultures late in infection resulted in rapid relocation of cytoplasmic ICP0 back into the nucleus. Exposure of HEL fibroblasts to MG132 late in infection resulted in the disappearance of the highly charged ICP0 G isoform. The G form of ICP0 was also absent in cells infected with R7914 mutant. In cells infected with this mutant, ICP0 is not translocated to the cytoplasm. (v) Last, cdc2 was active in infected cells, and this activity was inhibited by roscovitine. In contrast, the activity of cdk2 exhibited by immunoprecipitated protein was reduced and resistant to roscovitine and may represent a contaminating kinase activity. We conclude from these results that the ICP0 G isoform is the cytoplasmic form, that it may be phosphorylated by cdc2, consistent with evidence published earlier (S. J., Advani, R. R. Weichselbaum, and B. Roizman, Proc. Natl. Acad. Sci. USA 96:10996-11001, 2000), and that the processing is reversed upon relocation of the G isoform from the cytoplasm into the nucleus. The processing of ICP4 is also affected by R325 and roscovitine. The latter result suggests that ICP4 may also be a substrate of cdc2 late in infection. Last, additional modifications are superimposed by cell-type-specific enzymes.
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Affiliation(s)
- S J Advani
- The Marjorie B. Kovler Viral Oncology Laboratories, The University of Chicago, Chicago, Illinois 60637, USA.
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22
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Bronstein JC, Weber PC. Purification of a bacterially expressed herpes simplex virus type 1 origin binding protein for use in posttranslational processing studies. Protein Expr Purif 2001; 22:276-85. [PMID: 11437604 DOI: 10.1006/prep.2001.1446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The origin binding protein (OBP) encoded by the UL9 open reading frame of herpes simplex virus type 1 (HSV-1) plays an essential role in productive infection by promoting the initiation of viral DNA synthesis. In this study, OBP was inducibly expressed in Escherichia coli and purified to homogeneity using a two-step chromatographic separation procedure. The properties of this recombinant OBP (rOBP) were found to be indistinguishable from those of the virus-encoded protein. Since rOBP was synthesized in bacterial cells, it lacked the posttranslational processing which normally occurs in OBP produced in HSV-1-infected mammalian cells and could therefore be exploited in experiments which addressed the effects of protein modification on OBP function. As an initial study, the impact of phosphorylation on enzymatic activity was examined using rOBP which had been treated with a panel of purified cellular kinases. rOBP was found to act as a substrate for nearly all of the kinases tested in (32)P-labeled phosphate transfer assays. However, only phosphorylation by protein kinase A (PKA, or cAMP-dependent protein kinase) was shown to significantly alter the enzymatic properties of rOBP, as it increased by five- to eightfold the ATPase activity associated with this protein. Activation of this critical viral DNA replication enzyme by a cAMP-dependent kinase such as PKA may be of some relevance in the natural course of HSV-1 infections, since reactivation of latent virus is thought to involve both signal transduction events and the induction of viral DNA synthesis. Thus, the expression and purification strategy outlined in this work provides an economical source of unmodified HSV-1 OBP that should prove useful in future in vitro studies.
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Affiliation(s)
- J C Bronstein
- Infectious Diseases Section, Pfizer Global Research and Development, Ann Arbor, Michigan, 48105, USA
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23
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Jean S, LeVan KM, Song B, Levine M, Knipe DM. Herpes simplex virus 1 ICP27 is required for transcription of two viral late (gamma 2) genes in infected cells. Virology 2001; 283:273-84. [PMID: 11336552 DOI: 10.1006/viro.2001.0902] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The herpes simplex virus infected cell protein 27 (ICP27) is required for the expression of certain early viral proteins and for many late proteins during productive infection. Expression of at least one late (gamma 2) gene, that encoding glycoprotein C, is severely restricted in the absence of functional ICP27. The exact mode of action by which ICP27 induces late gene expression is not known, but the effect is apparent at the mRNA level as demonstrated by Northern blot analysis. To determine whether ICP27 activates late genes via transcriptional or posttranscriptional mechanisms, we initially used nuclear run-on assays to measure transcription of viral genes in Vero cells infected with wild-type (WT) virus or an ICP27 nonsense mutant virus, n504. We observed a 4-fold reduction in the nuclear run-on signal from the coding strand of the gC gene for n504-infected cells compared to that of WT-infected cells. However, interpretation of the results was complicated by the observation of a significant signal from the noncoding strand in these experiments. To obviate the problem of symmetrical transcription, we utilized in vivo RNA pulse-labeling to measure the amount of transcription of viral genes in cells infected with either WT virus or n504 virus. We found a 5- to 10-fold reduction in the transcription of the gC and U(L)47 genes, two late genes, in cells infected with n504 compared to that in cells infected with WT virus. In contrast, transcription of the ICP8 gene, an early gene, was similar in WT and n504 virus-infected cells. We also examined the stability of the gC and U(L)47 gene transcripts in n504-infected cells, and we found it to be comparable to that in WT virus-infected cells, further supporting an effect on transcription. Transcription of the gC and U(L)47 genes by n504 was normal in a cell line that expresses WT ICP27. From these results we conclude that ICP27 is required for transcription of the late gC and U(L)47 genes during productive infection.
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Affiliation(s)
- S Jean
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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24
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Izumiya Y, Jang HK, Ono M, Mikami T. A complete genomic DNA sequence of Marek's disease virus type 2, strain HPRS24. Curr Top Microbiol Immunol 2001; 255:191-221. [PMID: 11217423 DOI: 10.1007/978-3-642-56863-3_8] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- Y Izumiya
- Department of Veterinary Microbiology, Faculty of Agriculture, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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25
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Nuclear Export of Herpes Virus RNA. Curr Top Microbiol Immunol 2001. [DOI: 10.1007/978-3-642-56597-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Spengler ML, Ruyechan WT, Hay J. Physical interaction between two varicella zoster virus gene regulatory proteins, IE4 and IE62. Virology 2000; 272:375-81. [PMID: 10873781 DOI: 10.1006/viro.2000.0389] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transfection assays demonstrate that the varicella zoster virus (VZV) immediate-early 62 (IE62) protein is a major transactivator of VZV gene expression, whereas a second immediate-early protein, IE4, can act as a major coactivator of transactivation mediated through IE62. To test whether IE62 and IE4 interact physically, we performed several protein-protein interaction assays. Coimmunoprecipitation analyses using VZV-infected cell lysates as well as purified protein mixtures demonstrate that IE62 and IE4 form stable complexes in solution under stringent salt conditions. Enzyme-linked immunosorbent assay protein-protein interaction assays and maltose-binding protein capture assays demonstrate that IE62 binds IE4 in a concentration- and dose-dependent manner. Far Western blot analyses show that IE4 binds to an undermodified form of IE62, and the use of calf intestinal phosphatase and protein kinases suggests that the interaction with IE4 is dependent on the phosphorylation state of IE62. An IE4 binding domain on IE62 has been mapped using a set of truncated IE62 fusion peptides. Collectively, these results imply a direct and specific physical interaction between IE4 and less-phosphorylated forms of IE62. These data have implications for virion assembly, as well as for the regulation of gene expression in VZV-infected cells.
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Affiliation(s)
- M L Spengler
- Department of Microbiology and Markey Center for Microbial Pathogenesis, State University of New York at Buffalo School of Medicine, Buffalo, New York, 14214, USA
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27
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Kinchington PR, Fite K, Turse SE. Nuclear accumulation of IE62, the varicella-zoster virus (VZV) major transcriptional regulatory protein, is inhibited by phosphorylation mediated by the VZV open reading frame 66 protein kinase. J Virol 2000; 74:2265-77. [PMID: 10666257 PMCID: PMC111708 DOI: 10.1128/jvi.74.5.2265-2277.2000] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
IE62, the major transcriptional activator protein encoded by varicella-zoster virus (VZV), locates to the nucleus when expressed in transfected cells. We show here that cytoplasmic forms of IE62 accumulate in transfected and VZV-infected cells as the result of the protein kinase activity associated with VZV open reading frame 66 (ORF66). Expression of the ORF66 protein kinase but not the VZV ORF47 protein kinase impaired the ability of coexpressed IE62 to transactivate promoter-reporter constructs. IE62 that was coexpressed with the ORF66 protein accumulated predominantly in the cytoplasm, whereas the normal nuclear localization of other proteins was not affected by the ORF66 protein. In cells infected with VZV, IE62 accumulated in the cytoplasm at late times of infection, whereas in cells infected with a VZV recombinant unable to express ORF66 protein (ROka66S), IE62 was completely nuclear. Point mutations introduced into the predicted serine/threonine catalytic domain and ATP binding domain of ORF66 abrogated its ability to influence IE62 nuclear localization, indicating that the protein kinase activity was required. The region of IE62 that was targeted by ORF66 was mapped to amino acids 602 to 733. IE62 peptides containing this region were specifically phosphorylated in cells coexpressing the ORF66 protein kinase and in cells infected with wild-type VZV but were not phosphorylated in cells infected with ROka66S. We conclude that the ORF66 protein kinase phosphorylates IE62 to induce its cytoplasmic accumulation, most likely by inhibiting IE62 nuclear import.
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Affiliation(s)
- P R Kinchington
- Departments of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
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28
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Song B, Liu JJ, Yeh KC, Knipe DM. Herpes simplex virus infection blocks events in the G1 phase of the cell cycle. Virology 2000; 267:326-34. [PMID: 10662628 DOI: 10.1006/viro.1999.0146] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Infection of cells in G1 phase with herpes simplex virus (HSV) prevents their progression into S phase (de Bruyn Kops, A., and Knipe, D. M., 1988, Cell 55, 857-868). We have examined G1-phase events in infected cells to determine whether this effect was the result of inhibition of G1 phase progression or of entry into S phase. We observed that HSV infection decreased pRb phosphorylation and induced a new phosphorylated form of pRb. Furthermore, HSV infection prevented the normal G1 increases in cyclin D1 and D3 protein levels, and blocked the normal G1 appearance of new electrophoretic forms of cdk2 and cdk4. Thus, HSV infection inhibits several events that normally occur in the cell cycle during G1 phase, arguing that the HSV-induced block in the cell cycle occurs in early to mid-G1 phase.
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Affiliation(s)
- B Song
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, Massachusetts 02115, USA
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29
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Zhi Y, Sandri-Goldin RM. Analysis of the phosphorylation sites of herpes simplex virus type 1 regulatory protein ICP27. J Virol 1999; 73:3246-57. [PMID: 10074178 PMCID: PMC104088 DOI: 10.1128/jvi.73.4.3246-3257.1999] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The herpes simplex virus type 1 (HSV-1) regulatory protein ICP27 is a 63-kDa phosphoprotein required for viral replication. ICP27 has been shown to contain both stable phosphate groups and phosphate groups that cycle on and off during infection (K. W. Wilcox, A. Kohn, E. Sklyanskaya, and B. Roizman, J. Virol. 33:167-182, 1980). Despite extensive genetic analysis of the ICP27 gene, there is no information available about the sites of the ICP27 molecule that are phosphorylated during viral infection. In this study, we mapped several of the phosphorylation sites of ICP27 following in vivo radiolabeling. Phosphoamino acid analysis showed that serine is the only amino acid that is phosphorylated during infection. Two-dimensional phosphopeptide mapping showed a complex tryptic phosphopeptide pattern with at least four major peptides and several minor peptides. In addition, ICP27 purified from transfected cells yielded a similar phosphopeptide pattern, suggesting that cellular kinases phosphorylate ICP27 during viral infection. In vitro labeling showed that protein kinase A (PKA), PKC, and casein kinase II (CKII) were able to differentially phosphorylate ICP27, resulting in distinct phosphopeptide patterns. The major phosphorylation sites of ICP27 appeared to cluster in the N-terminal portion of the protein, such that a frameshift mutant that encodes amino acids 1 to 163 yielded a phosphopeptide pattern very similar to that seen with the wild-type protein. Further, using small deletion and point mutations in kinase consensus sites, we have elucidated individual serine residues that are phosphorylated in vivo. Specifically, the serine at residue 114 was highly phosphorylated by PKA and the serine residues at positions 16 and 18 serve as targets for CKII phosphorylation in vivo. These kinase consensus site mutants were still capable of complementing the growth of an ICP27-null mutant virus. Interestingly, phosphorylation of the serine at residue 114, which lies within the major nuclear localization signal, appeared to modulate the efficiency of nuclear import of ICP27.
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Affiliation(s)
- Y Zhi
- Department of Microbiology and Molecular Genetics, University of California, Irvine, California 92697-4025, USA
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30
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Panagiotidis CA, Silverstein SJ. The host-cell architectural protein HMG I(Y) modulates binding of herpes simplex virus type 1 ICP4 to its cognate promoter. Virology 1999; 256:64-74. [PMID: 10087227 DOI: 10.1006/viro.1999.9607] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The productive infection cycle of herpes simplex virus is controlled in part by the action of ICP4, an immediate-early gene product that acts as both an activator and repressor of transcription. ICP4 is autoregulatory, and IE-3, the gene that encodes it, contains a high-affinity binding site for the protein at its cap site. Previously, we had demonstrated that this site could be occupied by proteins found in nuclear extracts from uninfected cells. A HeLa cell cDNA expression library was screened with a DNA probe containing the IE-3 gene cap site, and clones expressing the architectural chromatin proteins HMG I and HMG Y were identified by this technique. HMG I is shown to augment binding of ICP4 to its cognate site in in vitro assays and to enhance the activity of this protein in short-term transient expression assays.
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Affiliation(s)
- C A Panagiotidis
- College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
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31
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Miller CS, Danaher RJ, Jacob RJ. Molecular aspects of herpes simplex virus I latency, reactivation, and recurrence. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1998; 9:541-62. [PMID: 9825226 DOI: 10.1177/10454411980090040901] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The application of molecular biology in the study of the pathogenesis of herpes simplex virus type 1 (HSV-1) has led to significant advances in our understanding of mechanisms that regulate virus behavior in sensory neurons and epithelial tissue. Such study has provided insight into the relationship of host and viral factors that regulate latency, reactivation, and recurrent disease. This review attempts to distill decades of information involving human, animal, and cell culture studies of HSV-1 with the goal of correlating molecular events with the clinical and laboratory behavior of the virus during latency, reactivation, and recurrent disease. The purpose of such an attempt is to acquaint the clinician/scientist with the current thinking in the field, and to provide key references upon which current opinions rest.
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Affiliation(s)
- C S Miller
- Department of Oral Health Science, University of Kentucky Colleges of Dentistry and Medicine, Lexington 40536-0084, USA
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32
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Sandri-Goldin RM. Interactions between a herpes simplex virus regulatory protein and cellular mRNA processing pathways. Methods 1998; 16:95-104. [PMID: 9774519 DOI: 10.1006/meth.1998.0647] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The herpes simplex virus type 1 (HSV-1) immediate-early regulatory protein ICP27 performs essential functions during viral lytic infection. Studies with viral mutants have demonstrated that ICP27 affects the shutoff of host protein synthesis, HSV-1 DNA replication, and the expression of viral early and late genes. Mounting evidence has been presented to demonstrate that ICP27 functions predominantly at the posttranscriptional level by affecting mRNA processing. That is, ICP27 alters poly(A) site usage, impairs host cell splicing, and facilitates the export of viral intronless mRNAs. These diverse effects occur by the interaction of ICP27 with viral and host proteins and by binding RNA. To define the precise mechanisms by which ICP27 affects RNA processing pathways, it is necessary to identify all of the molecular interactions of ICP27 in vivo and to determine the functional significance of these interactions. In vivo approaches will be emphasized here. Protein-protein interactions have been analyzed by coimmunoprecipitation studies, followed by immunoblotting to confirm the identity of coprecipitating proteins. Indirect immunofluorescence staining has been performed on cells treated with RNA polymerase II inhibitors to determine the intracellular distribution of ICP27 related to its RNA export function. Finally, in vivo UV irradiation has been used to covalently cross-link ICP27 to mRNAs in direct contact. This was followed with procedures to isolate and analyze the protein-RNA complexes. These studies have revealed several splicing complex proteins with which ICP27 interacts and have identified a number of intronless RNA transcripts to which ICP27 binds in the nucleus and cytoplasm in its role in RNA transport.
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Affiliation(s)
- R M Sandri-Goldin
- College of Medicine, University of California at Irvine, Irvine, California, 92697-4025, USA.
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33
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Bates PA, DeLuca NA. The polyserine tract of herpes simplex virus ICP4 is required for normal viral gene expression and growth in murine trigeminal ganglia. J Virol 1998; 72:7115-24. [PMID: 9696805 PMCID: PMC109933 DOI: 10.1128/jvi.72.9.7115-7124.1998] [Citation(s) in RCA: 24] [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
ICP4 of herpes simplex virus (HSV) is essential for productive infection due to its central role in the regulation of HSV transcription. This study identified a region of ICP4 that is not required for viral growth in culture or at the periphery of experimentally inoculated mice but is critical for productive growth in the trigeminal ganglia. This region of ICP4 encompasses amino acids 184 to 198 and contains 13 nearly contiguous serine residues that are highly conserved among the alphaherpesviruses. A mutant in which this region is deleted (DeltaSER) was able to grow on the corneas of mice and be transported back to the trigeminal ganglia. DeltaSER did not grow in the trigeminal ganglia but did express low levels of several immediate-early (ICP4 and ICP27) and early (thymidine kinase [tk] and UL42) genes. It expressed very low levels of the late gC gene and did not appear to replicate DNA. This pattern of gene expression was similar to that observed for a tk mutant, dlsptk. Both DeltaSER and dlsptk expressed higher levels of the latency-associated transcript (LAT) per genome earlier in infected ganglia than did the wild-type virus, KOS. However, infected ganglia from all three viruses accumulated the same level of LAT per genome at 30 days postinfection (during latency). The data suggest that the polyserine tract of ICP4 provides an activity that is required for lytic infection in ganglia to progress to viral DNA synthesis and full lytic gene expression. In the absence of this activity, higher levels of LAT per genome accumulate earlier in infection than with wild-type virus.
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Affiliation(s)
- P A Bates
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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34
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Harel NY, Alwine JC. Phosphorylation of the human cytomegalovirus 86-kilodalton immediate-early protein IE2. J Virol 1998; 72:5481-92. [PMID: 9621004 PMCID: PMC110188 DOI: 10.1128/jvi.72.7.5481-5492.1998] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We have investigated the phosphorylation state of the human cytomegalovirus 86-kDa immediate-early (IE) protein IEP86 from transfected and infected cells. We show that multiple domains of IEP86 are phosphorylated by cellular kinases, both in vitro and in vivo. Our data suggest that serum-inducible kinases play a significant role in cell-mediated IE protein phosphorylation and that a member of the mitogen-activated protein (MAP) kinase (MAPK) family, extracellular regulated kinase 2 (ERK2), phosphorylates several domains of IEP86 in vitro. Alanine substitution mutagenesis was performed on specific serines or threonines (T27, S144, T233/S234, and T555) found in consensus MAP kinase motifs. Analysis of these mutations showed that T27 and T233/S234 are the major sites for serum-inducible kinases and are the major ERK2 sites in vitro. S144 appeared to be phosphorylated in a serum-independent manner in vitro. All of the mutations except T555 eliminated specific phosphorylation in vivo. In transient transfection analyses, IEP86 isoforms containing mutations in S144 and, especially, T233/S234 displayed increased transcriptional activation relative to the wild type, suggesting that phosphorylation at these sites in wild-type IEP86 may result in reduction of its transcriptional activation ability.
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Affiliation(s)
- N Y Harel
- Graduate Group of Cell and Molecular Biology and Department of Microbiology, Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6142, USA
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35
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Panagiotidis CA, Lium EK, Silverstein SJ. Physical and functional interactions between herpes simplex virus immediate-early proteins ICP4 and ICP27. J Virol 1997; 71:1547-57. [PMID: 8995681 PMCID: PMC191212 DOI: 10.1128/jvi.71.2.1547-1557.1997] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The ordered expression of herpes simplex virus type 1 (HSV-1) genes, during the course of a productive infection, requires the action of the virus immediate-early regulatory proteins. Using a protein interaction assay, we demonstrate specific in vitro protein-protein interactions between ICP4 and ICP27, two immediate-early proteins of HSV-1 that are essential for virus replication. We map multiple points of contact between these proteins. Furthermore, by coimmunoprecipitation experiments, we demonstrate the following. (i) ICP4-ICP27 complexes are present in extracts from HSV-1 infected cells. (ii) ICP27 binds preferentially to less modified forms of ICP4, a protein that is extensively modified posttranslationally. We also demonstrate, by performing electrophoretic mobility shift assays and supershifts with monoclonal antibodies to ICP4 or ICP27, that both proteins are present in a DNA-protein complex with a noncanonical ICP4 binding site present in the HSV thymidine kinase (TK) gene. ICP4, in extracts from cells infected with ICP27-deficient viruses, is impaired in its ability to form complexes with the TK site but not with the canonical site from the alpha4 gene. However, ICP4 is able to form complexes with the TK probe, in the absence of ICP27, when overproduced in mammalian cells or expressed in bacteria. These data suggest that the inability of ICP4 from infected cell extracts to bind the TK probe in the absence of ICP27 does not reflect a requirement for the physical presence of ICP27 in the complex. Rather, they imply that ICP27 is likely to modulate the DNA binding activity of ICP4 by affecting its posttranslational modification status. Therefore, we propose that ICP27, in addition to its established role as a posttranscriptional regulator of virus gene expression, may also modulate transcription either through direct or indirect interactions with HSV regulatory regions, or through its ability to modulate the DNA binding activity of ICP4.
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Affiliation(s)
- C A Panagiotidis
- Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA
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36
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Miau LH, Chang CJ, Tsai WH, Lee SC. Identification and characterization of a nucleolar phosphoprotein, Nopp140, as a transcription factor. Mol Cell Biol 1997; 17:230-9. [PMID: 8972203 PMCID: PMC231747 DOI: 10.1128/mcb.17.1.230] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Expression of the alpha-1 acid glycoprotein (AGP) gene (agp) is activated by a key transcription factor, AGP/enhancer-binding protein (AGP/EBP, commonly called C/EBP beta), in the liver during the acute-phase response. In addition to this positive regulation, agp is negatively regulated by nucleolin (T. H. Yang et al., Mol. Cell. Biol. 14:6068-6074, 1994). Other factors involve in positive regulation of the agp gene are poorly characterized. In a systematic search for factors that may interact with AGP/EBP, we have identified Nopp 140, a phosphoprotein of 140 kDa, by immunoaffinity chromatography. Nopp 140 not only functions as a transcriptional activator per se but also interacts with AGP/EBP to synergistically activate the agp gene in an AGP/EBP-binding motif-dependent manner. In addition to interacting with AGP/EBP, Nopp140 interacts specifically with TFIIB. Distinct regions of Nopp140 that interact with AGP/EBP and TFIIB have been characterized. The sequence of Nopp140 contains several stretches of serine- and acidic amino acid-rich sequences which are also found in ICP4 of herpes simplex virus type 1, a known transcription factor that interacts with TFIIB. The physical interaction between TFIIB and wild-type Nopp140 or several deletion mutants of Nopp140 correlates with the ability of Nopp140 to activate the agp gene synergistically with AGP/EBP. Thus, the molecular mechanism for agp gene activation may involve the interaction of AGP/EBP and TFIIB mediated by coactivator Nopp140.
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Affiliation(s)
- L H Miau
- Institute of Biochemical Sciences, College of Science, National Taiwan University, Taipei
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37
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Sathananthan B, Rødahl E, Ekberg T, Langeland N, Haarr L. Two-dimensional gel analysis of [35S]methionine labelled and phosphorylated proteins present in virions and light particles of herpes simplex virus type 1, and detection of potentially new structural proteins. Virus Res 1996; 46:1-18. [PMID: 9029773 DOI: 10.1016/s0168-1702(96)01371-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cells infected with herpes simplex virus (HSV) synthesize both infectious viruses and non-infectious light particles (L-particles). The latter contain the envelope and tegument components of the virions, but lack virus capsid and DNA. Electrophoresis in SDS-polyacrylamide gels (SDS-PAGE) has been used extensively for analysis of structural proteins in virions and L-particles. Two-dimensional (2-D) gel electrophoresis, however has a markedly higher resolution, and in the present work we have used this technique to study both [35S]methionine labelled and phosphorylated structural proteins in virions and L-particles. Proteins were assigned to the tegument or the envelope by the analysis of L-particles. Localization of structural proteins was also determined by stepwise solubilization in the presence of the neutral detergent NP-40 and NaCl, and by isolation of capsids from nuclei of infected cells. Different steps in posttranslational modification can be detected by 2-D gel electrophoresis such that a single polypeptide may appear as several spots. This was most clearly observed for some of the HSV-encoded glycoproteins which were shown to exist in multiple forms in the virion. Some polypeptides apparently not identified previously were either capsid associated, or localized in the tegument or envelope. The degrees of phosphorylation in L-particles and virions are almost identical for some proteins, but markedly different for others. Thus, glycoprotein E of HSV-1 is for the first time shown to be phosphorylated, and most heavily so in virions. The IE VMW)110 protein represents a group of proteins which are more phosphorylated in L-particles than in virions. Attempts are made to correlate the proteins detected by 2-D analysis with those previously separated by SDS-PAGE.
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Affiliation(s)
- B Sathananthan
- Bergen High Technology Centre, University of Bergen, Norway
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38
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Xia K, Knipe DM, DeLuca NA. Role of protein kinase A and the serine-rich region of herpes simplex virus type 1 ICP4 in viral replication. J Virol 1996; 70:1050-60. [PMID: 8551563 PMCID: PMC189911 DOI: 10.1128/jvi.70.2.1050-1060.1996] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Efficient expression of herpes simplex virus genes requires the synthesis of functional ICP4, a nuclear phosphoprotein that contains a prominent serine-rich region between amino acids 142 and 210. Residues in this region not only are potential sites for phosphorylation but also are involved in the functions of ICP4. By comparing the growth of a virus in which this region is deleted (d8-10) with wild-type virus (KOS) in PC12 cells or PC12 cells that are deficient in cyclic AMP-dependent protein kinase (PKA), two observations were made: (i) the growth of wild-type virus was impaired by 1 to 2 orders of magnitude in the PKA-deficient cells, indicating the involvement of PKA in the growth cycle of herpes simplex virus type 1, and (ii) while the growth of d8-10 was impaired by almost 2 orders of magnitude in wild-type cells, it was not further impaired (as was that of wild-type virus) in PKA-deficient cells, implicating the region deleted in d8-10 as a possible target for cellular PKA. In trigeminal'ganglia of mice, the d8-10 mutant virus grew poorly; however, it established latency in nearly 90% of ganglia tested. Studies of the phosphorylation of wild-type and d8-10 ICP4 proteins revealed that the serine-rich region is a major determinant for phosphorylation of ICP4 in vivo and that the phosphorylation state could change as a function of the PKA activity. Consistent with this observation, the serine-rich region of ICP4 was shown to be a target for PKA in vitro. While intact ICP4 was readily phosphorylated by ICP4 in vitro, the d8-10 mutant ICP4 was not. Moreover, a synthethic peptide representing a sequence in the serine tract that is predicted to be a substrate for PKA was phosphorylated by PKA in vitro, having a Km within the physiological range. These data suggest that PKA plays a role in viral growth through phosphorylation of one or more sites on the ICP4 molecule.
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Affiliation(s)
- K Xia
- Committee on Virology, Harvard Medical School, Boston, Massachusetts 02115, USA
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