Viral RNA-binding protein KSHV ORF57 and host transcriptome
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE179728 | GEO | 2023/02/13
REPOSITORIES: GEO
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Project description:Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 is a viral RNA-binding protein essential for viral lytic gene expression. ORF57 binds to target RNA directly via interaction with cellular cofactors. To investigate the entire repertoire of ORF57-associated RNAs we performed UV cross-linking immunoprecipitatin (CLIP) experiment using an affinity-purified, highly specific anti-ORF57 antibody in KSHV-infected primariy effusion lymphoma BCBL-1 cells undegoing lytic virus replication.
2021-11-08 | GSE179726 | GEO
Project description:Kaposi's sarcoma-associated virus (KSHV) ORF57 is a viral RNA-binding protein required for proper posttranscriptional processing of viral transcripts including RNA splicing. To identify the viral splicing events regulated by ORF57 we performed a genome-wide analysis of RNA splicing of viral RNAs in wild type (WT) versus ORF57 knock-out (57KO) primary effusion lymphoma cells line BCBL-1 after induction of KSHV lytic replication by 24h treatment with valproic acid (VA).
2022-06-16 | GSE194239 | GEO
Project description:The Kaposi's sarcoma associated herpesvirus (KSHV) is an oncogenic virus that causes Kaposi's sarcoma, primary effusion lymphoma (PEL), and some forms of multicentric Castleman's disease. The KSHV ORF57 protein is a conserved posttranscriptional regulator of gene expression that is essential for virus replication. ORF57 is multifunctional, but most of its activities are directly linked to its ability to bind RNA. We globally identified virus and host RNAs bound by ORF57 during lytic reactivation in PEL cells using high-throughput sequencing of RNA isolated by crosslinking immunoprecipitation (HITS-CLIP). As expected, ORF57-bound RNA fragments mapped throughout the KSHV genome, including the known ORF57 ligand PAN RNA. In agreement with previously published ChIP results, we observed that ORF57 bound RNAs near the oriLyt regions of the genome. Examination of the host RNA fragments revealed that a subset of the ORF57-bound RNAs was derived from transcript 5´ ends. The position of these 5´-bound fragments correlated closely with the 5´-most exonintron junction of the pre-mRNA. We selected four candidates (BTG1, EGR1, ZFP36, and TNFSF9) and analyzed their pre-mRNA and mRNA levels during lytic phase. Analysis of both steady-state and newly made RNAs revealed that these candidate ORF57-bound pre-mRNAs persisted for longer periods of time throughout infection than control RNAs, consistent with a role for ORF57 in pre-mRNA metabolism. In addition, exogenous expression of ORF57 was sufficient to increase the pre-mRNA levels and, in one case, the mRNA levels of the putative ORF57 targets. These results demonstrate that ORF57 interacts with specific host pre-mRNAs during lytic reactivation and alters their processing, likely by stabilizing pre-mRNAs. These data suggest that ORF57 is involved in modulating host gene expression in addition to KSHV gene expression during lytic reactivation. HITS-CLIP was performed on TREx BCBL-Rta cells 20 hpi using antibodies against ORF57. Three biological replicates were performed.
2015-02-01 | E-GEOD-64413 | biostudies-arrayexpress
Project description:The Kaposi's sarcoma associated herpesvirus (KSHV) is an oncogenic virus that causes Kaposi's sarcoma, primary effusion lymphoma (PEL), and some forms of multicentric Castleman's disease. The KSHV ORF57 protein is a conserved posttranscriptional regulator of gene expression that is essential for virus replication. ORF57 is multifunctional, but most of its activities are directly linked to its ability to bind RNA. We globally identified virus and host RNAs bound by ORF57 during lytic reactivation in PEL cells using high-throughput sequencing of RNA isolated by crosslinking immunoprecipitation (HITS-CLIP). As expected, ORF57-bound RNA fragments mapped throughout the KSHV genome, including the known ORF57 ligand PAN RNA. In agreement with previously published ChIP results, we observed that ORF57 bound RNAs near the oriLyt regions of the genome. Examination of the host RNA fragments revealed that a subset of the ORF57-bound RNAs was derived from transcript 5´ ends. The position of these 5´-bound fragments correlated closely with the 5´-most exonintron junction of the pre-mRNA. We selected four candidates (BTG1, EGR1, ZFP36, and TNFSF9) and analyzed their pre-mRNA and mRNA levels during lytic phase. Analysis of both steady-state and newly made RNAs revealed that these candidate ORF57-bound pre-mRNAs persisted for longer periods of time throughout infection than control RNAs, consistent with a role for ORF57 in pre-mRNA metabolism. In addition, exogenous expression of ORF57 was sufficient to increase the pre-mRNA levels and, in one case, the mRNA levels of the putative ORF57 targets. These results demonstrate that ORF57 interacts with specific host pre-mRNAs during lytic reactivation and alters their processing, likely by stabilizing pre-mRNAs. These data suggest that ORF57 is involved in modulating host gene expression in addition to KSHV gene expression during lytic reactivation.
2015-02-01 | GSE64413 | GEO
Project description:The aging process is characterized by cellular functional decline and increased susceptibility to infections. Understanding the association between virus infection and aging is crucial for developing effective strategies against viral infections in older individuals. Kaposi's sarcoma-associated herpesvirus (KSHV) infection increases the risk of Kaposi's sarcoma, a vascular cancer prevalent among the elderly without HIV infection. However, the relationship between KSHV pathogenesis and cellular senescence remains unknown. Here, we demonstrate that KSHV infectivity is significantly increased in senescent human endothelial cells due to enhanced binding of virions to cell surface. Proteomic analysis identified caveolin-1 and CD109 that promote KSHV infection and were significantly upregulated in senescent cells. In particular, CD109 is expressed on cell surface and directly interacts with KSHV virions to enhance KSHV infection. Knockout of CD109 abolished while overexpression of CD109 promote KSHV binding to cell surface, and infectivity. These results identify CD109 as a novel KSHV entry receptor that enhances KSHV infection in senescent cells, which might in part explain the higher sensitivity of elder subjects to KSHV infection and Kaposi's sarcoma.
2024-04-17 | PXD048212 | Pride
Project description:lncRNAs regulate protein functions via formation of protein-RNA complexes. Previous studies have shown that expression of viral lncRNA, polyadenylated nuclear RNA (PAN RNA) is essential for inducible viral genomic looping and distal gene activation during Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation. Here we show an underlying molecular mechanism and regulation of KSHV latency by a viral lncRNA-CHD4 (chromodomain helicase DNA binding protein 4) interaction. Knock-out of the viral RNA binding protein, ORF57 protein, leads to decreased inducible and static viral genomic loops in latent chromatin and a failure to form RNA polymerase II aggregates in the nucleus during reactivation. We identified that CHD4's enzymatic activity silences viral gene expression by preventing nuclear aggregate formation. Furthermore, integrated genomic and proteomic studies together show that KSHV episomes frequently tether near the host cell centromeres and colocalize with a CHD4 protein complex, ChAHP. KSHV episomes detached from these sites when reactivation is triggered, and PAN RNA binds and inhibits CHD4 DNA binding in vitro. Our studies suggest that CHD4 exhibits strong repressor function by preventing inducible enhancer-promoter looping, and is therefore important for the ability of KSHV to establish and maintain latency in a “poised” state at specific host genomic loci.
2022-03-17 | GSE163098 | GEO
Project description:lncRNAs regulate protein functions via formation of protein-RNA complexes. Previous studies have shown that expression of viral lncRNA, polyadenylated nuclear RNA (PAN RNA) is essential for inducible viral genomic looping and distal gene activation during Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation. Here we show an underlying molecular mechanism and regulation of KSHV latency by a viral lncRNA-CHD4 (chromodomain helicase DNA binding protein 4) interaction. Knock-out of the viral RNA binding protein, ORF57 protein, leads to decreased inducible and static viral genomic loops in latent chromatin and a failure to form RNA polymerase II aggregates in the nucleus during reactivation. We identified that CHD4's enzymatic activity silences viral gene expression by preventing nuclear aggregate formation. Furthermore, integrated genomic and proteomic studies together show that KSHV episomes frequently tether near the host cell centromeres and colocalize with a CHD4 protein complex, ChAHP. KSHV episomes detached from these sites when reactivation is triggered, and PAN RNA binds and inhibits CHD4 DNA binding in vitro. Our studies suggest that CHD4 exhibits strong repressor function by preventing inducible enhancer-promoter looping, and is therefore important for the ability of KSHV to establish and maintain latency in a “poised” state at specific host genomic loci.
2022-03-17 | GSE163694 | GEO
Project description:Primari effusion lymphoma are (PEL) patient-derived transformed B-cells harboring latent Kaposi's sarcoma-associated herpesvirus (KSHV). The treatment of PEL cells with valproic acid (VA) leads to reactivation of KSHV and viral lytic replication. The aim of this project is to evaluate the effect of KSHV lytic infection on expression of the host transcriptome.
2021-11-08 | GSE179727 | GEO
Project description:Primary effusion lymphoma (PEL) is caused by Kaposi's sarcoma-associated herpesvirus (KSHV) and frequently also harbors Epstein-Barr virus (EBV). The expression of KSHV- and, often, EBV-encoded microRNAs (miRNAs) in PELs suggests a role for these miRNAs in viral latency and lymphomagenesis. Here we report the direct and transcriptome-wide identification of miRNA target sites for all miRNAs expressed in PEL cell lines. The resulting dataset revealed that KSHV miRNAs directly target more than 2000 cellular mRNAs encoding proteins that function in pathways with relevance to KSHV pathogenesis. Moreover, ~50% of these mRNAs are also targeted by EBV miRNAs, via distinct binding sites. In addition to a known viral analog of miR-155, we show that KSHV encodes a viral miRNA that mimics cellular miR-142-3p function. In summary, these experiments identify an extensive list of mRNAs targeted by KSHV miRNAs and indicate that these are likely to strongly influence viral replication and pathogenesis. small RNA sequencing, 3 samples Ago2 (EIF2C2) PAR-CLIP, 2 samples
2011-11-16 | E-GEOD-32109 | biostudies-arrayexpress
Project description:Kaposi's sarcoma-associated herpesvirus (KSHV) can efficiently infect and transform primary rat mesenchymal precursor (MM) cells. Regulation of cell cycle progression and apoptosis by KSHV-encoded microRNAs is required for KSHV-induced cellular transformation and tumorigenesis.
2013-08-28 | GSE50381 | GEO