Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Hijacking of transcriptional condensates by endogenous retroviruses

ABSTRACT: Heterochromatin plays essential roles in repressing retrotransposons, e.g. endogenous retroviruses (ERVs) during mammalian development, but the contribution of retrotransposition to lethality observed in embryonic cells deficient for heterochromatin-mediated ERV repression is poorly understood. Here we report that selective degradation of the TRIM28 heterochromatin adapter protein leads to reduced association of transcriptional condensates with loci encoding super-enhancer -driven pluripotency genes in embryonic stem cells, a collapse of the pluripotency transcriptional circuit, and a pre-lethal restriction of pluripotent lineages in mouse embryos. De-repressed ERVs recruit transcriptional condensates in the absence of TRIM28, and ERV RNA facilitates condensation of RNA Polymerase II in vitro. We propose that retrotransposons contribute to the genomic distribution of nuclear condensates, and that RNA species may facilitate “hijacking” of transcriptional condensates in various developmental and disease contexts.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Mus Musculus (mouse)

SUBMITTER: David Meierhofer

LAB HEAD: Alexander Meissner

PROVIDER: PXD021895 | Pride | 2022-07-08

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Similar Datasets

Hijacking of transcriptional condensates by endogenous retroviruses

Project description:Most endogenous retroviruses (ERVs) in mammals are incapable of retrotransposition; therefore, why ERV de-repression is associated with lethality during early development has been a mystery. Here we report that rapid and selective degradation of the TRIM28 heterochromatin adapter protein triggers dissociation of transcriptional condensates from loci encoding super-enhancer -driven pluripotency genes, and their association with transcribed ERV loci in murine embryonic stem cells. Knockdown of ERV RNAs or forced expression of super-enhancer -enriched transcription factors rescued condensate localization at super-enhancers in TRIM28-degraded cells. In a biochemical reconstitution system, ERV RNA facilitated partitioning of RNA Polymerase II, and the Mediator co- activator into phase-separated droplets. In TRIM28 knockout mouse embryos, single-cell RNA-Seq analysis revealed specific depletion of pluripotent lineages. We propose that coding and non-coding nascent RNAs, including those produced by retrotransposons, may facilitate “hijacking” of transcriptional condensates in various developmental and disease contexts.

2022-03-30 | GSE159468 | GEO

TRIM28 repression of retrotransposon-based enhancers is necessary to preserve transcriptional dynamics in embryonic stem cells

Project description:TRIM28 (KAP1 - KRAB-associated protein 1) is critical for the silencing of endogenous retroviruses (ERVs) in embryonic stem (ES) cells. Here, we reveal that an essential impact of this process is the protection of cellular gene expression in early embryos from perturbation by cis-acting activators contained within these genetic invaders. In TRIM28-depleted ES cells, repressive chromatin marks at ERVs are replaced by histone modifications typical of active enhancers, stimulating transcription of nearby cellular genes, notably those harboring bivalent promoters. Correspondingly, ERV-derived sequences can repress or enhance expression from an adjacent promoter in transgenic embryos depending on their TRIM28-sensitivity in ES cells. TRIM28-mediated control of ERVs is therefore crucial not just to prevent retrotransposition, but more broadly to safeguard the transcriptional dynamics of early embryos. Analyses of transcriptional profiles and chromatin state in TRIM28 WT and KO cells

2012-12-04 | E-GEOD-41903 | biostudies-arrayexpress

Hijacking of transcriptional condensates by endogenous retroviruses

Project description:Hijacking of transcriptional condensates by endogenous retroviruses

| PRJNA669013 | ENA

ChIP-MS of HP1-beta (CBX1) and ubiquitylome of KAP1 (TRIM28) in mESCs

Project description:Heterochromatin binding protein HP1β plays an important role in chromatin organization and cell differentiation, however the underlying mechanisms remain unclear. Here, we generated HP1β-/- embryonic stem cells and observed reduced heterochromatin clustering and impaired differentiation. We found that during stem cell differentiation, HP1β is phosphorylated at serine 89 by CK2, which creates a binding site for the pluripotency regulator KAP1. This phosphorylation dependent sequestration of KAP1 in heterochromatin compartments causes a downregulation of pluripotency factors and triggers pluripotency exit. Accordingly, HP1β-/- and phospho-mutant cells exhibited impaired differentiation, while ubiquitination-deficient KAP1ΔRing cells had the opposite phenotype with enhanced differentiation. These results suggest that KAP1 regulates pluripotency via its ubiquitination activity. We propose that the formation of subnuclear membraneless heterochromatin compartments may serve as a dynamic reservoir to trap or release cellular factors. The sequestration of essential regulators defines a novel and active role of heterochromatin in gene regulation and represents a dynamic mode of remote control to regulate cellular processes like cell fate decisions.

2021-09-24 | PXD025053 | Pride

TRIM28 repression of retrotransposon-based enhancers is necessary to preserve transcriptional dynamics in embryonic stem cells

2012-12-04 | GSE41903 | GEO

The HUSH complex cooperates with TRIM28 to repress young retrotransposons and new genes

Project description:Retrotransposons encompass half of the human genome and contribute to the formation of heterochromatin, which provides nuclear structure and regulates gene expression. Here, we asked if the human silencing hub (HUSH) complex is necessary to silence retrotransposons and whether it collaborates with TRIM28 and the chromatin remodeler ATRX at specific genomic loci. We show that the HUSH complex contributes to de novo repression and DNA methylation of a SVA retrotransposon reporter. By using naïve vs. primed mouse pluripotent stem cells, we reveal a critical role for the HUSH complex in naïve cells, implicating it in programming epigenetic marks in development. While the HUSH component TASOR binds to endogenous retroviruses (ERVs) and L1s, it is mainly required to repress evolutionarily young L1s. TRIM28, in contrast, is necessary to repress both ERVs and young L1s. Genes co-repressed by TRIM28 and TASOR are evolutionarily young, or exhibit tissue-specific expression, are enriched in young L1s and display evidence for regulation through LTR promoters. Finally, we demonstrate that the HUSH complex is also required to repress L1 elements in human cells. Overall, these data indicate that the HUSH complex and TRIM28 co-repress young retrotransposons and new genes rewired by retrotransposon non-coding DNA.

2018-01-17 | GSE107840 | GEO

Dnmt1 has de novo activity targeted to transposable elements

Project description:DNA methylation plays a critical role in development, particularly in repressing retrotransposons. The mammalian methylation landscape is dependent on the combined activities of the canonical maintenance enzyme Dnmt1 and the de novo Dnmts, 3a and 3b. Here we demonstrate that Dnmt1 displays de novo methylation activity in vitro and in vivo with specific retrotransposon targeting. We used whole-genome bisulfite and long-read Nanopore sequencing in genetically engineered methylation depleted embryonic stem cells to provide an in-depth assessment and quantification of this activity. Utilizing additional knockout lines and molecular characterization, we show that Dnmt1's de novo methylation activity depends on Uhrf1 and its genomic recruitment overlaps with targets that enrich for Trim28 and H3K9 trimethylation. Our data demonstrate that Dnmt1 can de novo add and maintain DNA methylation, especially at retrotransposons and that this mechanism may provide additional stability for long-term repression and epigenetic propagation throughout development.

2021-06-29 | PXD025736 | Pride

Deep proteomic profiling of TE03 (I3) human embryonic stem cells (hESCs)

Project description:The proteome of undifferentiated human embryonic stem cells (hESCs) was profiled by deep mass spectrometry-based proteomics of whole-cell extracts from suspension cultures of TE03 cells, in four biological replicates. This data accompanies the manuscript: "Uncovering the RNA-binding protein landscape in the pluripotency network of human embryonic stem cells". Abstract: "Embryonic stem cell (ESC) self-renewal and cell-fate decisions are driven by a broad array of molecular signals. While transcriptional regulators have been extensively studied in human ESCs (hESCs), the extent to which RNA-binding proteins (RBPs) contribute to human pluripotency remains unclear. Here, we carry out a proteome-wide screen and identify 810 proteins that directly bind RNA in hESCs. We reveal that RBPs are preferentially expressed in hESCs and dynamically regulated during exit from pluripotency and early lineage specification. Moreover, we show that nearly 200 RBPs are affected by knockdown of OCT4, a master regulator of pluripotency, several dozen of which are directly bound by this factor. Intriguingly, over 20 percent of the proteins detected in our study are putative DNA- and RNA-binding proteins (DRBPs), among them key transcription factors (TFs). Using fluorescently labeled RNA and seCLIP (single-end enhanced crosslinking and immunoprecipitation) experiments, we discover that the pluripotency-associated STAT3 and OCT4 TFs interact with RNA in hESCs and confirm the direct binding of STAT3 to the conserved NORAD long-noncoding RNA. Taken together, our findings indicate that RBPs have a more widespread role in human pluripotency than previously appreciated, reinforcing the importance of post-transcriptional regulation in stem cell biology".

2023-05-05 | PXD025278 | Pride

Chromatin dynamics and genome-wide profiling of repetitive elements during early mammalian embryogenesis.

Project description:We have used repetitive elements, including retrotransposons, as model loci to address how and when heterochromatin forms during development. High throughput RNA-sequencing using a Nano-CAGE protocol throughout early embryogenesis revealed that the expression of repetitive elements is abundant in embryonic cells, highly dynamic and stage-specific, with most repetitive elements becoming repressed before implantation. Furthermore, we show that Line L1 elements and IAP retrotransposons become reactivated from both parental genomes in mouse embryos after fertilisation, indicating an open chromatin configuration at the beginning of development. Our data show that the reprogramming process that follows fertilisation is accompanied by a robust transcriptional activation of retrotransposons and suggests that expression of repetitive elements is initially regulated through an RNA-dependent mechanism in mammals. Genome Wide profiling of CAGE transcripts using Nano-CAGE and RNAseq in oocytes and 3 different stages of mouse pre-implantation development

2013-01-27 | E-GEOD-39849 | biostudies-arrayexpress

Mass spectrometry based-proteomic analysis comparing the abundance of RNA-binding proteins (RBPs) between TE03 (I3) human embryonic stem cells (hESCs) and human foreskin fibroblasts (HFFs)

Project description:Here, we used high-resolution mass spectrometry to identify differentially expressed RNA-binding proteins (RBPs) between TE03 (I3) human embryonic stem cells (hESCs) and human foreskin fibroblasts (HFFs). 2102Ep embryonal carcinoma (EC) cells were used as a reference for pluripotent cells. This data accompanies the manuscript: "Uncovering the RNA-binding protein landscape in the pluripotency network of human embryonic stem cells". Abstract: "Embryonic stem cell (ESC) self-renewal and cell-fate decisions are driven by a broad array of molecular signals. While transcriptional regulators have been extensively studied in human ESCs (hESCs), the extent to which RNA-binding proteins (RBPs) contribute to human pluripotency remains unclear. Here, we carry out a proteome-wide screen and identify 810 proteins that directly bind RNA in hESCs. We reveal that RBPs are preferentially expressed in hESCs and dynamically regulated during exit from pluripotency and early lineage specification. Moreover, we show that nearly 200 RBPs are affected by knockdown of OCT4, a master regulator of pluripotency, several dozen of which are directly bound by this factor. Intriguingly, over 20 percent of the proteins detected in our study are putative DNA- and RNA-binding proteins (DRBPs), among them key transcription factors (TFs). Using fluorescently labeled RNA and seCLIP (single-end enhanced crosslinking and immunoprecipitation) experiments, we discover that the pluripotency-associated STAT3 and OCT4 TFs interact with RNA in hESCs and confirm the direct binding of STAT3 to the conserved NORAD long-noncoding RNA. Taken together, our findings indicate that RBPs have a more widespread role in human pluripotency than previously appreciated, reinforcing the importance of post-transcriptional regulation in stem cell biology".

2023-05-05 | PXD025284 | Pride

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data