Multiple long-range cis interactions generate CTCF insulator-dependent viral chromatin domains in quiescent HSV-1 genomes
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PROVIDER: PRJNA1284398 | ENA |
REPOSITORIES: ENA
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Project description:In cellular genomes, CTCF insulators impact transcription over small distances in a one-dimensional manner and over much longer distances in a three-dimensional manner by maintaining chromatin loops. We have previously shown that the latent HSV-1 genome contains CTCF insulators that function to regulate lytic transcription of adjacent genes in a one-dimensional manner. Here, we test the hypothesis that HSV-1 CTCF insulators nucleate chromatin loops to regulate the expression of distance separated gene regions through three-dimensional organization of viral genomes. We used 4C-seq methods to identify multiple long-range cis interactions in HSV-1 genomes that generate viral chromatin domains, including those nucleated by the viral CTCF insulator CTRL2. Deletion of the CTRL2 insulator disrupted these viral chromatin domains. Loop-nucleating interactions were quantitated with a novel approach (UMI-4C-seq) that utilizes unique molecular identifiers to label and count chromatin interactions associated with specific viewpoint primers. Cis-interaction peaks across four different viewpoints were quantified. Viral genomes lacking CTRL2 displayed more cis-interaction peaks and wider ranges of interaction lengths compared to wt virus, suggesting altered chromatin organization. Furthermore, differential looping analysis showed viral genomes lacking CTRL2 displayed a more transcriptionally permissive chromatin environment. Thus, the CTRL2 insulator functions as a critical regulator of long-range chromatin interactions and its deletion reshapes the viral chromatin landscape, leading to a more accessible and dynamic regulatory environment that may influence HSV-1 transcriptional programs and latency-associated chromatin states.
2025-07-03 | GSE301274 | GEO
Project description:Chromatin insulators are DNA-protein complexes that can prevent the spread of repressive chromatin and block communication between enhancers and promoters to regulate gene expression. In Drosophila, the gypsy chromatin insulator complex consists of three core proteins: CP190, Su(Hw), and Mod(mdg4)67.2. These factors concentrate at nuclear foci termed insulator bodies, and their normal localization is correlated with proper insulator function. Here, we identified NURF301/E(bx), a nucleosome remodeling factor, as a novel regulator of gypsy insulator body localization through a high-throughput RNAi imaging screen. NURF301 promotes gypsy-dependent insulator barrier activity and physically interacts with gypsy insulator proteins. Using ChIP-seq, we found that NURF301 co-localizes with insulator proteins genome-wide, and NURF301 promotes chromatin association of Su(Hw) and CP190 at gypsy insulator binding sites. These effects correlate with NURF301-dependent nucleosome repositioning. At the same time, CP190 and Su(Hw) are also required for recruitment of NURF301 to chromatin. Finally, Oligopaint FISH combined with immunofluorescence revealed that NURF301 promotes 3D contact between insulator bodies and gypsy binding site DNA, and NURF301 is required for proper nuclear positioning of gypsy binding sites. Our data provide new insights into how a nucleosome remodeling factor and insulator proteins cooperatively contribute to nuclear organization.
2022-10-14 | PXD032165 | Pride
Project description:The cellular insulator CCCTC-binding factor (CTCF) plays a role in HSV-1 latency through the establishment of chromatin boundaries. We previously found that the CTRL2 regulatory element downstream from the LAT enhancer is bound by CTCF during latency and undergoes CTCF eviction at early times post-reactivation in mice latent with 17Syn+ . It has been previously shown that the CTRL2 binding domain is a functional insulator with both enhancer-blocking and silencing capabilities. Considering these findings, we hypothesized that the CTRL2 site plays a key role in regulating latent HSV-1 gene expression. To test this, we used a mutant virus with a 135 bp deletion spanning only the core CTRL2 domain (DCTRL2) in the 17Syn+ background. Following ocular infection of mice, we found significant differences between DCTRL2 and wild-type virus during the acute infection and latency. Notably, mouse mortalities were significantly higher in the DCTRL2 virus compared to the 17Syn+, while lower viral genomes were found after latency indicating that deletion of CTRL2 site disrupted latency establishment. This fact, coupled with increased LAT intron and VP16 expression indicated that the establishment of latency was disrupted in the DCTRL2 mutant. These data provide evidence that chromatin domains of the latent HSV-1 genome are in part maintained by the CTRL2 binding.
2019-04-05 | GSE128258 | GEO
Project description:Herpes simplex virus type 1 (HSV-1) is a 152 Kb double stranded DNA alpha-herpesvirus, which establishes long life latent infection in sensory neurons. Most of our knowledge regarding HSV-1 latency comes from in vivo studies using small animal models, mainly rodents and rabbits, which are not naturally infected by HSV-1. Furthermore, these animal models do not fully recapitulate the species specific effects of human HSV-1 infection. Human cellular models utilize trigeminal ganglia removed from cadavers or, alternatively, neuron-like cells derived from cancerous cell lines that do not fully reflect effects on normal human neurons. This limitation poses the need to develop an in vitromodel to investigate molecular details of the mechanisms underlying quiescence and reactivation in human neurons. Induced pluripotent stem (iPS) celltechnologies offer an unprecedented opportunity to generate unlimited supplies of neurons and the facility to manipulate such cells in vitro. In this study, we developed an in vitro HSV-1 infection model in human iPS-derived neurons, which displays the main hallmarks of latency defined in animal models and in humans. Our results show for the first time that: i) persistent infection cannot be established in neural progenitor cells (NPCs); ii) the ability of HSV-1 to establish persistent infection is extended to glutamatergic neurons, and not limited to sensory neurons; iii) in neuronal cultures persistently infected with HSV-1, viral genome is localized at the nuclear periphery; iv) HSV-1 acute infection reduces RNA editing at the GluRB site. These results highlight the importance of iPS-based platforms to elucidate unknown aspects of HSV-1 quiescence in human neurons. NPCs were 70-80% confluence
2014-05-02 | E-GEOD-46042 | biostudies-arrayexpress
Project description:Herpes simplex virus type 1 (HSV-1) is a 152 Kb double stranded DNA alpha-herpesvirus, which establishes long life latent infection in sensory neurons. Most of our knowledge regarding HSV-1 latency comes from in vivo studies using small animal models, mainly rodents and rabbits, which are not naturally infected by HSV-1. Furthermore, these animal models do not fully recapitulate the species specific effects of human HSV-1 infection. Human cellular models utilize trigeminal ganglia removed from cadavers or, alternatively, neuron-like cells derived from cancerous cell lines that do not fully reflect effects on normal human neurons. This limitation poses the need to develop an in vitro model to investigate molecular details of the mechanisms underlying latency and reactivation in human neurons. Induced pluripotent stem (iPS) cell technologies offer an unprecedented opportunity to generate unlimited supplies of neurons and the facility to manipulate such cells in vitro. In this study, we developed an in vitro HSV-1 infection model in human iPS-derived neural progenitor cells (NPCs) and neurons, which displays the main hallmarks of latency defined in animal models and in humans. Induced pluripotent stem (iPS) cells were generated from human skin biopsy samples
2014-05-02 | E-GEOD-46041 | biostudies-arrayexpress
Project description:we reporter the transcritional difference after THP-1 cells were infected with HSV-1UL37WT virus or HSV-1UL37C819S virus.
2018-05-29 | GSE114966 | GEO
Project description:We used the technology of ChIP-sequencing to analyze changes in H3K27me3 levels in Drosophila Schneider S2 depleted of endogenous Beaf32 and expressing insulator mutants ('mut-Beaf32' or 'muBeaf') as compared to control cells expressing wild-type Beaf32 (Control; 'CTL')
2020-04-28 | GSE130211 | GEO
Project description:Chromatin insulators organize the genome into distinct transcriptional domains and contribute to cell type-specific chromatin organization. However, factors regulating tissue-specific insulator function have not yet been discovered. Here we identify the RNA recognition motif-containing protein, Shep, as a direct interactor of two individual components of the gypsy insulator complex in Drosophila. Mutation of shep improves gypsy-dependent enhancer blocking, indicating a role as a negative regulator of insulator activity. Unlike ubiquitously expressed core gypsy insulator proteins, Shep is highly expressed in the central nervous system (CNS) with lower expression in other tissues. We developed a novel, quantitative tissue-specific barrier assay to demonstrate that Shep functions as a negative regulator of insulator activity in the CNS but not in muscle tissue. Additionally, mutation of shep alters insulator complex nuclear localization in the CNS but not other tissues. Consistent with negative regulatory activity, ChIP-seq analysis of Shep in a CNS-derived cell line indicates substantial genome-wide colocalization with a single gypsy insulator component but limited overlap with intact insulator complexes. Taken together, these data reveal a novel, tissue-specific mode of regulation of a chromatin insulator.
2012-11-30 | GSE40797 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE8542: BY4742 Quiescent and Non-quiescent replicates GSE8558: Proteinase K treatment of Q and NQ cells GSE8559: S288c Quiescent and Non-quiescent replicates GSE8560: Mutant1 GSE8561: Mutant2 Refer to individual Series
2010-05-29 | E-GEOD-8624 | biostudies-arrayexpress
Project description:To investigate the effect of HSV infection on glioma cells, we established a model of HSV infection
2023-06-27 | GSE235568 | GEO