Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Orphan CpG islands boost the regulatory activity of poised enhancers and dictate the responsiveness of their target genes

ABSTRACT: CpG islands (CGIs) represent a unique and widespread genetic feature of vertebrate genomes, being associated with ~70% of all annotated gene promoters. CGIs have been proposed to control transcription initiation by conferring nearby promoters with unique chromatin properties. In addition, there are thousands of distal or orphan CGIs (oCGIs) whose functional relevance and mechanism of action are barely known. Here we show that oCGIs are an essential component of poised enhancers (PEs) that boost their long-range regulatory activity and dictate the responsiveness of their target genes. Using a CRISPR/Cas9 knock-in strategy in mESC, we introduced PEs with or without oCGIs within topological associating domains (TADs) harbouring genes with different types of promoters. By evaluating the chromatin, topological and regulatory properties of the engineered PEs, we uncovered that, rather than increasing their local activation, the oCGI boost the physical and functional communication between PEs and distally located developmental genes. Furthermore, we demonstrate that developmental genes with CpG rich promoters are particularly responsive to PEs and that such responsiveness depends on the presence of oCGI. Therefore, our work unveils a novel role for CGIs as genetic determinants of the compatibility between genes and enhancers, which has major implications for the current understanding of how developmental gene expression programs are deployed as well as for our ability to predict the pathological consequences of human structural variation.

ORGANISM(S): Mus musculus

PROVIDER: GSE156465 | GEO | 2020/08/20

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

The SAM domain-containing protein 1 (SAMD1) acts as a repressive chromatin regulator at unmethylated CpG islands

Project description:CpG-islands (CGIs) are key regulatory DNA elements at most promoters, but how they influence the chromatin status and transcription remains elusive. Here we identify and characterize SAMD1 (SAM domain-containing protein 1) as an unmethylated CGI-binding protein. SAMD1 possesses an atypical winged-helix domain that directly recognizes unmethylated CpG-containing DNA via simultaneous interactions with both the major and the minor groove. The SAM domain interacts with L3MBTL3, but it can also homopolymerize into a closed pentameric ring. At a genome-wide level, SAMD1 localizes to H3K4me3-decorated CGIs, where it acts as a repressor. SAMD1 tethers L3MBTL3 to chromatin and interacts with the KDM1A histone demethylase complex to modulate H3K4me2 and H3K4me3 levels at CGIs, thereby providing a mechanism for SAMD1-mediated transcriptional repression. Absence of SAMD1 impairs ES cell differentiation processes, leading to mis-regulation of key biological pathways. Together, our work establishes SAMD1 as a novel chromatin regulator acting at unmethylated CGIs.

2021-05-13 | PXD016781 | Pride

CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (ChIP-seq)

Project description:One clear hallmark of mammalian promoters is the presence of CpG islands (CGIs) at more than two thirds of genes whereas TATA boxes are only present at a minority of promoters. Using genome-wide approaches, we show that GC content and CGIs are major promoter elements in mammalian cells, able to govern open chromatin conformation and support paused transcription. First, we define three classes of promoters with distinct transcriptional directionality and pausing properties which correlate with their GC content. We further analyze the direct influence of GC content on nucleosome positioning and depletion, and show that CGIs correlate with nucleosome depletion both in vivo and in vitro. We also show that transcription is not essential for nucleosome exclusion but influences both a weak +1 and a well-positioned nucleosome at CGI borders. Altogether our data support the idea that CGIs have become an essential feature of promoter structure defining novel regulatory properties in mammals. Nucleosome density and positioning were studied by high-throughput sequencing of DNA previously treated with Mnase. In parallel, chIPseq for PolII and H3K27ac were performed in mouse and human with different conditions to assess a potential effect of transcription on nucleosomes properties.

2012-06-12 | E-GEOD-38561 | biostudies-arrayexpress

CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (MNase-seq)

2012-06-12 | E-GEOD-38563 | biostudies-arrayexpress

CpG islands and GC content dictate nucleosome depletion in a transcription independent manner at mammalian promoters (genomic SEQ)

2012-06-11 | E-GEOD-38562 | biostudies-arrayexpress