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Lotke R, Schneeweiß U, Pietrek M, Günther T, Grundhoff A, Weidner-Glunde M, Schulz TF. Brd/BET Proteins Influence the Genome-Wide Localization of the Kaposi's Sarcoma-Associated Herpesvirus and Murine Gammaherpesvirus Major Latency Proteins. Front Microbiol 2020; 11:591778. [PMID: 33193257 PMCID: PMC7642799 DOI: 10.3389/fmicb.2020.591778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 09/28/2020] [Indexed: 01/22/2023] Open
Abstract
The rhadinoviruses Kaposi’s Sarcoma-associated herpesvirus (KSHV) and murine gammaherpesvirus (MHV-68) persist in infected hosts in a latent state that is characterized by the absence of virus production and by restricted viral gene expression. Their major latency protein, the latency-associated nuclear antigen (kLANA for KSHV and mLANA for MHV-68), is essential for viral genome maintenance and replication and involved in transcriptional regulation. Both kLANA and mLANA interact with cellular chromatin-associated proteins, among them the Bromodomain and Extra Terminal domain (Brd/BET) proteins, which recruit cellular and viral proteins to acetylated histones through their bromodomains and modulate cellular gene expression. Brd/BET proteins also play a role in the tethering, replication, segregation or integration of a diverse group of viral DNA genomes. In this study we explored if Brd/BET proteins influence the localization of the LANAs to preferential regions in the host chromatin and thereby contribute to kLANA- or mLANA-mediated transcriptional regulation. Using ChIP-Seq, we revealed a genome-wide co-enrichment of kLANA with Brd2/4 near cellular and viral transcriptional start sites (TSS). Treatment with I-BET151, an inhibitor of Brd/BET, displaced kLANA and Brd2/4 from TSS in the viral and host chromatin, but did not affect the direct binding of kLANA to kLANA-binding sites (LBS) in the KSHV latent origin of replication. Similarly, mLANA, but not a mLANA mutant deficient for binding to Brd2/4, also associated with cellular TSS. We compared the transcriptome of KSHV-infected with uninfected and kLANA-expressing human B cell lines, as well as a murine B cell line expressing mLANA or a Brd2/4-binding deficient mLANA mutant. We found that only a minority of cellular genes, whose TSS are occupied by kLANA or mLANA, is transcriptionally regulated by these latency proteins. Our findings extend previous reports on a preferential deposition of kLANA on cellular TSS and show that this characteristic chromatin association pattern is at least partially determined by the interaction of these viral latency proteins with members of the Brd/BET family of chromatin modulators.
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Affiliation(s)
- Rishikesh Lotke
- Institut für Virologie, Medizinische Hochschule Hannover, Hanover, Germany.,German Center for Infection Research, Hannover-Braunschweig and Hamburg Sites, Hanover, Germany
| | - Ulrike Schneeweiß
- Institut für Virologie, Medizinische Hochschule Hannover, Hanover, Germany
| | - Marcel Pietrek
- Institut für Virologie, Medizinische Hochschule Hannover, Hanover, Germany
| | - Thomas Günther
- Heinrich-Pette-Institut, Leibniz-Institut für Experimentelle Virologie, Hamburg, Germany
| | - Adam Grundhoff
- German Center for Infection Research, Hannover-Braunschweig and Hamburg Sites, Hanover, Germany.,Heinrich-Pette-Institut, Leibniz-Institut für Experimentelle Virologie, Hamburg, Germany
| | - Magdalena Weidner-Glunde
- Institut für Virologie, Medizinische Hochschule Hannover, Hanover, Germany.,German Center for Infection Research, Hannover-Braunschweig and Hamburg Sites, Hanover, Germany
| | - Thomas F Schulz
- Institut für Virologie, Medizinische Hochschule Hannover, Hanover, Germany.,German Center for Infection Research, Hannover-Braunschweig and Hamburg Sites, Hanover, Germany
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Epigenetic Alterations in Human Papillomavirus-Associated Cancers. Viruses 2017; 9:v9090248. [PMID: 28862667 PMCID: PMC5618014 DOI: 10.3390/v9090248] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 08/25/2017] [Accepted: 08/25/2017] [Indexed: 12/15/2022] Open
Abstract
Approximately 15–20% of human cancers are caused by viruses, including human papillomaviruses (HPVs). Viruses are obligatory intracellular parasites and encode proteins that reprogram the regulatory networks governing host cellular signaling pathways that control recognition by the immune system, proliferation, differentiation, genomic integrity, and cell death. Given that key proteins in these regulatory networks are also subject to mutation in non-virally associated diseases and cancers, the study of oncogenic viruses has also been instrumental to the discovery and analysis of many fundamental cellular processes, including messenger RNA (mRNA) splicing, transcriptional enhancers, oncogenes and tumor suppressors, signal transduction, immune regulation, and cell cycle control. More recently, tumor viruses, in particular HPV, have proven themselves invaluable in the study of the cancer epigenome. Epigenetic silencing or de-silencing of genes can have cellular consequences that are akin to genetic mutations, i.e., the loss and gain of expression of genes that are not usually expressed in a certain cell type and/or genes that have tumor suppressive or oncogenic activities, respectively. Unlike genetic mutations, the reversible nature of epigenetic modifications affords an opportunity of epigenetic therapy for cancer. This review summarizes the current knowledge on epigenetic regulation in HPV-infected cells with a focus on those elements with relevance to carcinogenesis.
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CCHCR1 interacts with EDC4, suggesting its localization in P-bodies. Exp Cell Res 2014; 327:12-23. [DOI: 10.1016/j.yexcr.2014.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 05/09/2014] [Accepted: 05/13/2014] [Indexed: 01/17/2023]
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Kvaratskhelia M, Sharma A, Larue RC, Serrao E, Engelman A. Molecular mechanisms of retroviral integration site selection. Nucleic Acids Res 2014; 42:10209-25. [PMID: 25147212 PMCID: PMC4176367 DOI: 10.1093/nar/gku769] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Retroviral replication proceeds through an obligate integrated DNA provirus, making retroviral vectors attractive vehicles for human gene-therapy. Though most of the host cell genome is available for integration, the process of integration site selection is not random. Retroviruses differ in their choice of chromatin-associated features and also prefer particular nucleotide sequences at the point of insertion. Lentiviruses including HIV-1 preferentially integrate within the bodies of active genes, whereas the prototypical gammaretrovirus Moloney murine leukemia virus (MoMLV) favors strong enhancers and active gene promoter regions. Integration is catalyzed by the viral integrase protein, and recent research has demonstrated that HIV-1 and MoMLV targeting preferences are in large part guided by integrase-interacting host factors (LEDGF/p75 for HIV-1 and BET proteins for MoMLV) that tether viral intasomes to chromatin. In each case, the selectivity of epigenetic marks on histones recognized by the protein tether helps to determine the integration distribution. In contrast, nucleotide preferences at integration sites seem to be governed by the ability for the integrase protein to locally bend the DNA duplex for pairwise insertion of the viral DNA ends. We discuss approaches to alter integration site selection that could potentially improve the safety of retroviral vectors in the clinic.
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Affiliation(s)
- Mamuka Kvaratskhelia
- Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Amit Sharma
- Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Ross C Larue
- Center for Retrovirus Research and College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Erik Serrao
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
| | - Alan Engelman
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
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Muller M, Demeret C. CCHCR1 interacts specifically with the E2 protein of human papillomavirus type 16 on a surface overlapping BRD4 binding. PLoS One 2014; 9:e92581. [PMID: 24664238 PMCID: PMC3963918 DOI: 10.1371/journal.pone.0092581] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 02/24/2014] [Indexed: 01/22/2023] Open
Abstract
The Human Papillomavirus E2 proteins are key regulators of the viral life cycle, whose functions are commonly mediated through protein-protein interactions with the host cell proteome. We identified an interaction between E2 and a cellular protein called CCHCR1, which proved highly specific for the HPV16 genotype, the most prevalent in HPV-associated cancers. Further characterization of the interaction revealed that CCHCR1 binds the N-terminal alpha helices of HPV16 E2 N-terminal domain. On this domain, the CCHCR1 binding interface overlaps that of BRD4, a key mediator of E2 transcriptional activity. Consequently a physical competition occurs between the two proteins for the binding to HPV16 E2, and CCHCR1 interferes with BRD4-mediated enhancement of E2-dependent transcription. In addition, we showed that the interaction with CCHCR1 induced a massive redistribution of HPV16 E2, from a predominantly nuclear to a cytoplasmic localization in dot-like structures, where E2 perfectly co-localizes with CCHCR1. Such a cytoplasmic docking likely interferes with the nuclear functions of HPV16 E2. Upon co-expression of BRD4 and CCHCR1, E2 accumulates both in the nucleus and in the cytoplasm, indicating that for HPV16, both sub-cellular localization and transcriptional functions of E2 may depend on the proportion of both factors within the cell. We provided evidence of a strong induction of the keratinocyte differentiation marker K10 by HPV16 E2, and showed that this activation is compromised by the interaction with CCHCR1. The specific interaction described here could thus impact on the pathogenesis of HPV16. We propose that it could underlie some specific traits of HPV16 infection, such as an enhanced propensity to give rise to lesions evolving toward cancer.
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Affiliation(s)
- Mandy Muller
- Unité Génétique Papillomavirus et Cancer Humain, Institut Pasteur, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France
| | - Caroline Demeret
- Unité Génétique Papillomavirus et Cancer Humain, Institut Pasteur, Paris, France
- * E-mail:
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McBride AA, Jang MK. Current understanding of the role of the Brd4 protein in the papillomavirus lifecycle. Viruses 2013; 5:1374-94. [PMID: 23722886 PMCID: PMC3717712 DOI: 10.3390/v5061374] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/21/2013] [Accepted: 05/21/2013] [Indexed: 12/19/2022] Open
Abstract
The Brd4 protein is an epigenetic reader that is central to regulation of cellular transcription and mitotic bookmarking. The transcription and replication proteins of many viruses interact with Brd4. We describe the multiple roles of Brd4 in the papillomavirus lifecycle.
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Affiliation(s)
- Alison A McBride
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Muller M, Demeret C. The HPV E2-Host Protein-Protein Interactions: A Complex Hijacking of the Cellular Network. Open Virol J 2012; 6:173-89. [PMID: 23341853 PMCID: PMC3547520 DOI: 10.2174/1874357901206010173] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 07/20/2012] [Accepted: 07/30/2012] [Indexed: 11/22/2022] Open
Abstract
Over 100 genotypes of human papillomaviruses (HPVs) have been identified as being responsible for unapparent infections or for lesions ranging from benign skin or genital warts to cancer. The pathogenesis of HPV results from complex relationships between viral and host factors, driven in particular by the interplay between the host proteome and the early viral proteins. The E2 protein regulates the transcription, the replication as well as the mitotic segregation of the viral genome through the recruitment of host cell factors to the HPV regulatory region. It is thereby a pivotal factor for the productive viral life cycle and for viral persistence, a major risk factor for cancer development. In addition, the E2 proteins have been shown to engage numerous interactions through which they play important roles in modulating the host cell. Such E2 activities are probably contributing to create cell conditions appropriate for the successive stages of the viral life cycle, and some of these activities have been demonstrated only for the oncogenic high-risk HPV. The recent mapping of E2-host protein-protein interactions with 12 genotypes representative of HPV diversity has shed some light on the large complexity of the host cell hijacking and on its diversity according to viral genotypes. This article reviews the functions of E2 as they emerge from the E2/host proteome interplay, taking into account the large-scale comparative interactomic study.
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Affiliation(s)
- Mandy Muller
- Unité de Génétique, Papillomavirus et Cancer Humain (GPCH), Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France ; Univ. Paris Diderot, Sorbonne Paris cite, Cellule Pasteur, rue du Docteur Roux, 75015 Paris, France
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Pacholska-Bogalska J, Myga-Nowak M, Ciepłuch K, Józefiak A, Kwaśniewska A, Goździcka-Józefiak A. Analysis of the coding sequence and expression of the coiled-coil α-helical rod protein 1 gene in normal and neoplastic epithelial cervical cells. Int J Mol Med 2012; 29:669-76. [PMID: 22218424 PMCID: PMC3577136 DOI: 10.3892/ijmm.2012.877] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 12/02/2011] [Indexed: 12/17/2022] Open
Abstract
The role of the CCHCR1 (coiled-coil α-helical rod protein 1) protein in the cell is poorly understood. It is thought to be engaged in processes such as proliferation and differentiation of epithelial cells, tissue-specific gene transcription and steroidogenesis. It is supposed to participate in keratinocyte transformation. It has also been found that this protein interacts with the E2 protein of human papilloma virus type 16 (HPV16). The oncogenic HPV forms, such as HPV16, are known to be necessary but not sufficient agents in the development of cervical carcinoma. In the present study, the CCHCR1 gene coding sequence and its expression was analyzed in normal, precancerous and cervical cancer cells. Changes in the non-coding region were found in 20.3% of the examined probes from women with cervical cancer or precancerous lesions and in 16.67% of the control probes. Most of the detected changes were single nucleotide polymorphisms (SNPs). Changes in the coding region were found in 22.8% of the probes with cervical cancer and in 16.67% of the control probes and all of them were SNPs. The level of CCHCR1 transcripts was determined using the real-time PCR method and the highest gene expression was detected in the H-SIL group and slightly decreased in the cervical carcinoma cells, compared with the control probes. It suggests that CCHCR1 could have a role in the process of cervical epithelial cell transformation, but this suggestion must be confirmed experimentally.
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Affiliation(s)
- Joanna Pacholska-Bogalska
- Department of Animal Physiology and Development, Adam Mickiewicz University, ul. Umultowska 89, 61-614 Poznan, Poland.
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