Dataset Information

Biphasic euchromatin-to-heterochromatin transition on the KSHV genome following de novo infection.

ABSTRACT: The establishment of latency is an essential step for the life-long persistent infection and pathogenesis of Kaposi's sarcoma-associated herpesvirus (KSHV). While the KSHV genome is chromatin-free in the virions, the viral DNA in latently infected cells has a chromatin structure with activating and repressive histone modifications that promote latent gene expression but suppress lytic gene expression. Here, we report a comprehensive epigenetic study of the recruitment of chromatin regulatory factors onto the KSHV genome during the pre-latency phase of KSHV infection. This demonstrates that the KSHV genome undergoes a biphasic chromatinization following de novo infection. Initially, a transcriptionally active chromatin (euchromatin), characterized by high levels of the H3K4me3 and acetylated H3K27 (H3K27ac) activating histone marks, was deposited on the viral episome and accompanied by the transient induction of a limited number of lytic genes. Interestingly, temporary expression of the RTA protein facilitated the increase of H3K4me3 and H3K27ac occupancy on the KSHV episome during de novo infection. Between 24-72 hours post-infection, as the levels of these activating histone marks declined on the KSHV genome, the levels of the repressive H3K27me3 and H2AK119ub histone marks increased concomitantly with the decline of lytic gene expression. Importantly, this transition to heterochromatin was dependent on both Polycomb Repressive Complex 1 and 2. In contrast, upon infection of human gingiva-derived epithelial cells, the KSHV genome underwent a transcription-active euchromatinization, resulting in efficient lytic gene expression. Our data demonstrate that the KSHV genome undergoes a temporally-ordered biphasic euchromatin-to-heterochromatin transition in endothelial cells, leading to latent infection, whereas KSHV preferentially adopts a transcriptionally active euchromatin in oral epithelial cells, resulting in lytic gene expression. Our results suggest that the differential epigenetic modification of the KSHV genome in distinct cell types is a potential determining factor for latent infection versus lytic replication of KSHV.

SUBMITTER: Toth Z

PROVIDER: S-EPMC3868514 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Biphasic euchromatin-to-heterochromatin transition on the KSHV genome following de novo infection.

Toth Zsolt Z Brulois Kevin K Lee Hye-Ra HR Izumiya Yoshihiro Y Tepper Clifford C Kung Hsing-Jien HJ Jung Jae U JU

PLoS pathogens 20131219 12

The establishment of latency is an essential step for the life-long persistent infection and pathogenesis of Kaposi's sarcoma-associated herpesvirus (KSHV). While the KSHV genome is chromatin-free in the virions, the viral DNA in latently infected cells has a chromatin structure with activating and repressive histone modifications that promote latent gene expression but suppress lytic gene expression. Here, we report a comprehensive epigenetic study of the recruitment of chromatin regulatory fac ...[more]

PMID: 24367262

Similar Datasets

Project description:The establishment of latency is an essential step for the life-long persistent infection and pathogenesis of KaposiM-bM-^@M-^Ys sarcoma-associated herpesvirus (KSHV). While the KSHV genome is chromatin-free in the virions, the viral DNA in latently infected cells has a chromatin structure that is characterized by a specific pattern of activating and repressive histone modifications that ultimately promote latent gene expression while suppressing lytic gene expression. To investigate the molecular events involved in the establishment of the latent chromatin structure during the pre-latency phase of KSHV infection, we performed a comprehensive epigenetic study to analyze the recruitment of chromatin regulatory factors onto the KSHV genome at various time-points following de novo infection of SLK and TIME cells. This showed that the KSHV genome undergoes a biphasic chromatinization following de novo infection. Initially, a transcriptionally active chromatin (euchromatin), characterized by high levels of the H3K4me3 and acetylated H3K27 (H3K27ac) activating histone marks, was deposited on the viral episome and was accompanied by the temporary induction of a limited number of lytic genes. Interestingly, transient expression of the RTA protein facilitated the increases of H3K4me3 and H3K27ac occupancy on the KSHV episome during de novo infection. Between 24-72 hours post-infection, as the levels of these activating histone marks declined on the KSHV genome, the levels of the repressive H3K27me3 and H2AK119ub histone marks increased concomitantly with the decline of lytic gene expression. Importantly, this transition to heterochromatin was dependent on both the Polycomb Repressive Complex 2 and 1. In contrast, upon infection of human gingiva-derived epithelial cells, the KSHV genome underwent a continuously transcription-active euchromatinization, resulting in efficient lytic gene expression. Our data demonstrate that the KSHV genome undergoes a temporally ordered biphasic euchromatin-to-heterochromatin transition in endothelial cells, leading to latent infection, whereas KSHV preferentially adopts a transcriptionally active euchromatin in oral epithelial cells, resulting in lytic gene expression. Our results suggest that the differential epigenetic modification of the KSHV genome in distinct cell types is a potential determining factor for latent infection vs. lytic replication of KSHV. Please see above. 16 hybridizations: ChIP and Input DNA

Project description:The establishment of latency is an essential step for the life-long persistent infection and pathogenesis of Kaposi’s sarcoma-associated herpesvirus (KSHV). While the KSHV genome is chromatin-free in the virions, the viral DNA in latently infected cells has a chromatin structure that is characterized by a specific pattern of activating and repressive histone modifications that ultimately promote latent gene expression while suppressing lytic gene expression. To investigate the molecular events involved in the establishment of the latent chromatin structure during the pre-latency phase of KSHV infection, we performed a comprehensive epigenetic study to analyze the recruitment of chromatin regulatory factors onto the KSHV genome at various time-points following de novo infection of SLK and TIME cells. This showed that the KSHV genome undergoes a biphasic chromatinization following de novo infection. Initially, a transcriptionally active chromatin (euchromatin), characterized by high levels of the H3K4me3 and acetylated H3K27 (H3K27ac) activating histone marks, was deposited on the viral episome and was accompanied by the temporary induction of a limited number of lytic genes. Interestingly, transient expression of the RTA protein facilitated the increases of H3K4me3 and H3K27ac occupancy on the KSHV episome during de novo infection. Between 24-72 hours post-infection, as the levels of these activating histone marks declined on the KSHV genome, the levels of the repressive H3K27me3 and H2AK119ub histone marks increased concomitantly with the decline of lytic gene expression. Importantly, this transition to heterochromatin was dependent on both the Polycomb Repressive Complex 2 and 1. In contrast, upon infection of human gingiva-derived epithelial cells, the KSHV genome underwent a continuously transcription-active euchromatinization, resulting in efficient lytic gene expression. Our data demonstrate that the KSHV genome undergoes a temporally ordered biphasic euchromatin-to-heterochromatin transition in endothelial cells, leading to latent infection, whereas KSHV preferentially adopts a transcriptionally active euchromatin in oral epithelial cells, resulting in lytic gene expression. Our results suggest that the differential epigenetic modification of the KSHV genome in distinct cell types is a potential determining factor for latent infection vs. lytic replication of KSHV. Please see above.

Project description:Constitutive heterochromatin is enriched in repetitive sequences and histone H3-methylated-at-lysine 9. Both components contribute to heterochromatin's ability to silence euchromatic genes. However, heterochromatin also harbors hundreds of expressed genes in organisms such as Drosophila. Recent studies have provided a detailed picture of sequence organization of D. melanogaster heterochromatin, but how histone modifications are associated with heterochromatic sequences at high resolution has not been described. Here, distributions of modified histones in the vicinity of heterochromatic genes of normal embryos and embryos homozygous for a chromosome rearrangement were characterized using chromatin immunoprecipitation and genome tiling arrays. We found that H3-di-methylated-at-lysine 9 (H3K9me2) was depleted at the 5' ends but enriched throughout transcribed regions of heterochromatic genes. The profile was distinct from that of euchromatic genes and suggests that heterochromatic genes are integrated into, rather than insulated from, the H3K9me2-enriched domain. Moreover, the profile was only subtly affected by a Su(var)3-9 null mutation, implicating a histone methyltransferase other than SU(VAR)3-9 as responsible for most H3K9me2 associated with heterochromatic genes in embryos. On a chromosomal scale, we observed a sharp transition to the H3K9me2 domain, which coincided with increased retrotransposon density in the euchromatin-heterochromatin (eu-het) transition zones on the long chromosome arms. Thus, a certain density of retrotransposons, rather than specific boundary elements, may demarcate Drosophila pericentric heterochromatin. We also demonstrate that a chromosome rearrangement that created a new eu-het junction altered H3K9me2 distribution and induced new euchromatic sites of enrichment as far as several megabases away from the breakpoint. Taken together, the findings argue against simple classification of H3K9me as the definitive signature of silenced genes, and clarify roles of histone modifications and repetitive DNAs in heterochromatin. The results are also relevant for understanding the effects of chromosome aberrations and the megabase scale over which epigenetic position effects can operate in multicellular organisms.

Dataset Information

Biphasic euchromatin-to-heterochromatin transition on the KSHV genome following de novo infection.

Publications

Biphasic euchromatin-to-heterochromatin transition on the KSHV genome following de novo infection.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets