Regulation of c-Myc function by centromeric protein KLIP1
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE21951 | GEO | 2024/05/01
REPOSITORIES: GEO
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Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is a g-herpesvirus which persists as circular extrachromasomal DNA in the nucleus during latent infection. During latency a limited number of viral proteins are expressed, including LANA (latency-associated nuclear antigen). LANA is a multi-functional protein known to interact with transcriptional regulators and chromatin remodelers, and to regulate the LANA and RTA promoters. We hypothesized that LANA may contribute to the establishment of latency through controlling chromatinization and histone modification of KSHV episomes. We performed ChIP-seq analysis and correlated H3K4me3, H3K27me3, polII, and LANA occupancy of the KSHV genome at nucleotide resolution. Epigenetic marks were analyzed in BCBL-1 lymphoid cells and in telomerase-immortalized vein endothelial TIVE-LTC cells. We found that the transcription active mark H3K4me3, but not silencing mark H3K27me3, was enriched at KSHV regions where LANA is bound. Co-occupancy of LANA and H3K4 was also detected on 167 host genes, of which 89 are actively transcribed. By comparing LANA occupancy with the profiling of 43 transcription factors from ENCODE, a subset of transcription factors was enriched at regions where LANA is bound, including znf143, CTCF, and Stat1. These results indicate that LANA also plays a role in modulating expression of host genes. Co-immunoprecipitation of LANA with the H3K4 methyltransferase hSET1 suggests that LANA recruits hSET1 to specific loci on the viral genome, leading to H3K4 methylation and ensuring transcription of latency-associated genes. Host gene expression may be regulated by the same mechanism. LANA binding was correlated with the distribution in the latent KSHV genome of the transcription active histone modification H3K4me3, the silencing mark H3K27me3, and RNA polymerase II, using cells of lymphoid and endothelial origin. A similar analysis was done for the human genome. Biological replicates (BR) and technical replicates (TR) were included.
2014-10-27 | E-GEOD-52421 | biostudies-arrayexpress
Project description:Kaposi’s Sarcoma (KS) is a heterogenous, multifocal vascular malignancy caused by the human herpesvirus 8 (HHV8), also known as Kaposi’s Sarcoma-Associated Herpesvirus (KSHV). Here, we show that KS lesions express iNOS/NOS2 broadly throughout KS lesions, with enrichment in LANA positive spindle cells. The iNOS byproduct 3-nitrotyrosine is also enriched in LANA positive tumor cells and colocalizes with a fraction of LANA-nuclear bodies. We show that iNOS is highly expressed in the L1T3 tumor model of KS. iNOS expression correlated with KSHV lytic cycle gene expression, which was elevated in late-stage tumors (>4 weeks) but to a lesser degree in early stage (1 week) xenografts. Further, we show that L1T3 tumor growth is sensitive to an inhibitor of nitric oxide, L-NMMA. These finding suggest that iNOS is expressed in KSHV infected endothelial-transformed tumor cells in KS, that iNOS expression depends on tumor microenvironment stress conditions, and that iNOS enzymatic activity contributes to KS tumor growth.
2023-07-14 | GSE222527 | GEO
Project description:Kaposi’s sarcoma-associated herpesvirus (KSHV) is a g-herpesvirus which persists as circular extrachromasomal DNA in the nucleus during latent infection. During latency a limited number of viral proteins are expressed, including LANA (latency-associated nuclear antigen). LANA is a multi-functional protein known to interact with transcriptional regulators and chromatin remodelers, and to regulate the LANA and RTA promoters. We hypothesized that LANA may contribute to the establishment of latency through controlling chromatinization and histone modification of KSHV episomes. We performed ChIP-seq analysis and correlated H3K4me3, H3K27me3, polII, and LANA occupancy of the KSHV genome at nucleotide resolution. Epigenetic marks were analyzed in BCBL-1 lymphoid cells and in telomerase-immortalized vein endothelial TIVE-LTC cells. We found that the transcription active mark H3K4me3, but not silencing mark H3K27me3, was enriched at KSHV regions where LANA is bound. Co-occupancy of LANA and H3K4 was also detected on 167 host genes, of which 89 are actively transcribed. By comparing LANA occupancy with the profiling of 43 transcription factors from ENCODE, a subset of transcription factors was enriched at regions where LANA is bound, including znf143, CTCF, and Stat1. These results indicate that LANA also plays a role in modulating expression of host genes. Co-immunoprecipitation of LANA with the H3K4 methyltransferase hSET1 suggests that LANA recruits hSET1 to specific loci on the viral genome, leading to H3K4 methylation and ensuring transcription of latency-associated genes. Host gene expression may be regulated by the same mechanism.
2014-10-27 | GSE52421 | GEO
Project description:Kaposi’s Sarcoma herpesvirus (KSHV), an oncogenic virus, modulates host cell signaling and metabolism to maintain latent infection. To unravel the underlying cellular mechanisms modulated by KSHV, we identified changes in the host proteome, phosphoproteome and transcriptome landscape upon KSHV infection of endothelial cells. A Steiner Forest algorithm was used to integrate proteomic, phosphoproteomic and transcriptomic data with transcriptome based predicted transcription factor activity to identify cellular networks altered by latent KSHV.
2017-02-08 | GSE84237 | GEO
Project description:Higher order genome structure influences the transcriptional regulation of cellular genes through the juxtaposition of regulatory elements, such as enhancers, close to promoters of target genes. While enhancer activation has emerged as an important facet of Kaposi’s sarcoma-associated herpesvirus (KSHV) biology, mechanisms controlling enhancer-target gene expression remain obscure. Here, we discover that the KSHV genome tethering protein latency-associated nuclear antigen (LANA) potentiates enhancer-target gene expression in primary effusion lymphoma (PEL), a highly aggressive B cell lymphoma causally associated with KSHV. Genome-wide analyses demonstrate increased levels of enhancer RNA transcription as well as activating chromatin marks at LANA bound enhancers. 3D-genome conformation analyses identified genes critical for latency and tumorigenesis as targets of LANA occupied enhancers, and LANA depletion results in their downregulation. These findings reveal a previously unknown mechanism in enhancer-gene coordination and describe a role through which the main KSHV tethering protein regulates essential gene expression in PEL.
2024-01-31 | GSE231452 | GEO
Project description:Latency-associated nuclear antigen (LANA), a multifunctional protein expressed by the Kaposi sarcoma-associated herpesvirus (KSHV) in latently-infected cells, is required for stable maintenance of the viral episome. This is mediated by two interactions: LANA binds to specific sequences (LBS1 and 2) on viral DNA, and also engages host histones, tethering the viral genome to host chromosomes in mitosis. LANA has also been suggested to affect host gene expression, but both the mechanism(s) and role of this dysregulation in KSHV biology remain unclear. Here we have examined LANA interactions with host chromatin on a genome-wide scale using ChIP-seq, and show that LANA predominantly targets human genes near their transcriptional start sites (TSSs). These host LANA-binding sites are generally found within transcriptionally active promoters and display striking overrepresentation of a consensus DNA sequence virtually identical to the LBS1 motif in KSHV DNA. Comparison of the ChIP-seq profile with whole transcriptome (RNA-seq) data reveals that few of the genes that are differentially regulated in latent infection are occupied by LANA at their promoters. This suggests that direct LANA binding to promoters is not the prime determinant of altered host transcription in KSHV-infected cells. Most surprisingly, the association of LANA to both host and viral DNA is strongly disrupted during the lytic cycle of KSHV. This disruption can be prevented by the inhibition of viral DNA synthesis, suggesting the existence of novel and potent regulatory mechanisms linked to either viral DNA replication or late gene expression. Profiling of KSHV LANA positioning on the host genome and examination of gene expression from promoters bound by KSHV LANA.
2014-04-01 | E-GEOD-56144 | biostudies-arrayexpress
Project description:The epitranscriptomic modification m6A is a ubiquitous feature of the mammalian transcriptome. It modulates mRNA fate and dynamics to exert regulatory control over numerous cellular processes and disease pathways, including viral infection. Kaposi’s sarcoma-associated herpesvirus (KSHV) reactivation from the latent phase leads to redistribution of m6A topology upon both viral and cellular mRNAs within infected cells. Here we investigate the role of m6A in cellular transcripts upregulated during KSHV lytic replication. Results show that m6A is crucial for the stability of the GPRC5A mRNA, whose expression is induced by the KSHV latent-lytic switch master regulator, the replication and transcription activator (RTA) protein. Moreover, we demonstrate that GPRC5A is essential for efficient KSHV lytic replication by directly regulating NFκB signalling. Overall, this work highlights the central importance of m6A in modulating cellular gene expression to influence viral infection.
2023-07-20 | PXD039669 | Pride
Project description:Human SLK cells were infected with wildtype (wt) and LANA knockout (KO) Kaposi's sarcoma-associated herpesvirus (KSHV), separately for 3 days. Cellular gene expression changes were identified upon the wild type and LANA KO KSHV virus infection compared to the uninfected SLK cells using the human gene expression microarray U133plus2.0. 2 independent biological replicates from uninfected SLK cells, wild type KSHV infected SLK cells at 72hrs post-infection (hpi) , and LANA KO infected SLK cells at 72 hrs post-infection were collected and RNA was prepared for microarray analysis.
2016-08-01 | E-GEOD-78282 | biostudies-arrayexpress
Project description:Human SLK cells were infected with wildtype (wt) and LANA knockout (KO) Kaposi's sarcoma-associated herpesvirus (KSHV), separately for 3 days. Cellular gene expression changes were identified upon the wild type and LANA KO KSHV virus infection compared to the uninfected SLK cells using the human gene expression microarray U133plus2.0.
2016-08-01 | GSE78282 | GEO
Project description:The Kaposi’s Sarcoma-associated Herpesvirus (KSHV) is the etiologic agent of several human cancers, including Kaposi’s Sarcoma (KS), which preferentially arise in immunocompromised patients but lack of effective therapeutic options. We have previously shown that KSHV or viral protein LANA can upregulate the glycoprotein CD147 (Emmprin) to induce primary endothelial cell invasiveness, which also requires PI3K/Akt and MAPK activation of VEGF production. In the current study, we first time identify the global network controlled by CD147 in KSHV-infected endothelial cells using Illumina microarray analysis. Among these downstream genes, ADAMTS1 and 9, two specific metalloproteases are strongly expressed in AIDS-KS tissues and contributed to KSHV-infected cell invasiveness through regulation of related cytokines production and respective receptors expression. By using a nude mice KS-like model, we found that targeting CD147 and downstream ADAMTSs proteins significantly suppressed KSHV-related tumorigenesis in vivo, which is potentially through impairing extracellular matrix (ECM) formation in tumor microenvironment. Taken together, we think that targeting CD147 and related proteins may represent a promising therapeutic strategy against KSHV-related malignancies.
2016-05-31 | GSE69067 | GEO