A Cut/cohesin axis altersthe chromatin landscape to facilitate neuroblast death
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE124998 | GEO | 2019/04/17
REPOSITORIES: GEO
Similar Datasets
Project description:A Cut/cohesin axis altersthe chromatin landscape to facilitate neuroblast death
| PRJNA514805 | ENA
Project description:Precise control of cell death in the nervous system is essential for development. Spatial and temporal factors activate the death of Drosophila neural stem cells (neuroblasts) by controlling the transcription of multiple cell death genes through a shared enhancer. The activity of this enhancer is controlled by abdominal A and Notch, but additional inputs are needed for proper specificity. Here, we show that the Cut DNA binding protein is required for neuroblast death, regulating reaper and grim downstream of the shared enhancer and of abdominal A expression. The loss of cut accelerates the temporal progression of neuroblasts from a state of low overall levels of H3K27me3 to a higher H3K27me3 state. This is reflected in an increase in H3K27me3 modifications in the cell death gene locus in the CNS on Cut knockdown. We also show that cut regulates the expression of the cohesin subunit Stromalin. Stromalin and the cohesin regulatory subunit Nipped-B are required for neuroblast death, and knockdown of Stromalin increases H3K27me3 levels in neuroblasts. Thus, Cut and cohesin regulate apoptosis in the developing nervous system by altering the chromatin landscape.
| S-EPMC6526717 | biostudies-literature
Project description:Inborn defects in DNA repairare associated with complex developmental disorders whose causal mechanisms are poorly understood. Using an in vivo biotinylation tagging approach in mice, we show that the nucleotide excision repair (NER) structure-specific endonuclease ERCC1-XPF complex interacts with the insulator binding protein CTCF, the cohesin subunits SMC1A and SMC3 and with MBD2; the factors co-localize with ATRX at the promoters and control regions (ICRs) of imprinted genes during postnatal hepatic development. Loss of Ercc1or exposure to mitomycin C triggers the localization of CTCF to heterochromatin, the dissociation of the CTCF-cohesin complex and ATRXfrom promoters and ICRs,altered histone marks and the aberrant developmental expression of imprinted genes without altering DNA methylation. We propose that ERCC1-XPF cooperates with CTCF and the cohesinto facilitatet he developmental silencing of imprinted genes and that persistent DNA damage triggers chromatin changes that affect gene expression programs associated with NER disorders.
2017-04-04 | PXD005897 | Pride
Project description:In addition to mediating sister chromatid cohesion, cohesin plays a central role in DNA looping and segmentation of the genome into contact domains (TADs). Two variant cohesin complexes that contain either STAG/SA1 or SA2 are present in all cell types. Here we addressed their specific contribution to genome architecture in non-transformed human cells. We found that cohesin-SA1 drives stacking of cohesin rings at CTCF-bound sites and thereby contributes to the stabilization and preservation of TAD boundaries. In contrast, a more dynamic cohesin-SA2 promotes cell type-specific contacts between enhancers and promoters within TADs independently of CTCF. SA2 loss, a condition frequently observed in cancer cells, results in increased intra-TAD interactions, likely altering the expression of key cell identity genes.
2018-05-31 | GSE101921 | GEO
Project description:Sequencing files provided here include mouse liver ChIP-seq for CTCF and the cohesin subunit Rad21. These files are part of a larger study ("CTCF and Cohesin link sex-biased distal regulatory elements to sex-biased gene expression in mouse liver") where we compare CTCF and cohesin binding in male and female mouse liver as well as differences in chromatin conformation (DNA looping).
2020-07-07 | GSE130908 | GEO
Project description:CTCF sites are abundant in the genomes of diverse species but their function is enigmatic. We used chromosome conformation capture to determine long-range interactions among CTCF/cohesin sites over 2 Mb on human chromosome 11 encompassing the β-globin locus and flanking olfactory receptor genes. Although CTCF occupies these sites in both erythroid K562 cells and fibroblast 293T cells, the long-range interaction frequencies among the sites are highly cell type specific, revealing a more densely clustered organization in the absence of globin gene activity. Both CTCF and cohesins are required for the cell-type-specific chromatin conformation. Furthermore, loss of the organizational loops in K562 cells through reduction of CTCF with shRNA results in acquisition of repressive histone marks in the globin locus and reduces globin gene expression, whereas silent flanking olfactory receptor genes are unaffected. These results support a genome-wide role for CTCF/cohesin sites through loop formation that both influences transcription and contributes to cell-type-specific chromatin organization and function. Comparison of CTCF binding in K562 and 293T cells using ChIP-chip. 3 replicates each cell type, ChIP and input DNA for each replicate.
2011-01-13 | E-GEOD-26507 | biostudies-arrayexpress
Project description:The functions of cohesin are central to genome integrity, chromosome organization, and transcription regulation through its prevention of premature sister-chromatid separation and the formation of DNA loops. The loading of cohesin onto chromatin depends on the Scc2-Scc4 complex, however, little is known about how it stimulates the cohesin loading activity. Here we determine the large “hook” structure of Scc2 responsible for catalyzing cohesin loading. We identify key Scc2 surfaces that are crucial for DNA binding and for cohesin loading in vivo. Using previously determined structures and modeling, we derive a pseudo-atomic structure of the full-length Scc2-Scc4 complex. Finally, our crosslinking and electron microscopy analyses reveal that Scc2-Scc4 utilizes its modular structure to make multiple contacts with a folded cohesin at an interface created by the cohesin head-hinge interaction.
2017-01-11 | PXD004692 | Pride
Project description:Cohesin shapes the nuclear chromatin architecture, including enhancer-promoter interactions,
and its components, of which especially STAG2 and RAD21, are frequently mutated in myeloid
malignancies. To elucidate mechanisms of leukemogenesis associated with cohesin mutations
in humans, we comprehensively characterized genetic, epigenetic, transcriptional, and
chromatin conformational changes in acute myeloid leukemia (AML). To corroborate our
findings, we performed complementary siRNA-mediated depletion of STAG2, its paralogue
STAG1 or RAD21 in cord blood-derived CD34+ primary human hematopoietic stem and
progenitor cells (HSPCs). We show that STAG2 mutations consistently lead to the loss of
STAG2 protein and are associated with a specific set of co-occurring mutations, while STAG1
was never mutated in AML. Loss of STAG2 was frequently compensated by STAG1. Still,
specific loci displayed altered cohesin occupancy, gene expression and corresponding changes
in local chromatin activation as measured by H3K27ac enrichment and chromatin accessibility.
High-throughput chromosome conformation capture (in-situ Hi-C) revealed significantly
altered chromatin looping in cohesin-mutated AMLs, including weakened enhancer-promoter
contacts with reduced, cohesin-dependent promoter activity. In HSPCs, we detected
transcriptomic and epigenetic effects overlapping STAG2-mutant AML-specific changes
following STAG2 knockdown (KD), that were not invoked by the depletion of STAG1. We
also found that STAG2 loss in cultured HSPCs impaired the differentiation capacity, especially
erythroid colony formation which maintained HSPC-like gene expression. This work
establishes STAG2 as a key regulator of cohesin-associated chromatin architecture, gene
expression and differentiation in the human hematopoietic system and identifies candidate
target genes that may be implicated in leukemogenesis.
| EGAS00001007405 | EGA
Project description:The cohesin complex has crucial roles in many structural and functional aspects of chromosomes including sister chromatid cohesion, genome organization, gene transcription and DNA repair. Cohesin recruitment onto chromosomes requires nucleosome free DNA and a specialized cohesin loader complex comprised of the Scc2 and Scc4 subunits. The cohesin loader, in addition to stimulating cohesin ATP hydrolysis and facilitating topological loading onto DNA, leads cohesin to chromatin receptors such as the RSC chromatin remodeling complex. Here, we explore the cohesin loader-RSC interaction and show that its Scc4 subunit contacts a conserved RSC ATPase motor module. The cohesin loader enhances RSC chromatin remodeling activity in vitro, as well as promoter nucleosome eviction in vivo. These findings provide insight into how the cohesin loader recognizes, as well as influences, the chromatin landscape, with implications for our understanding of human developmental disorders including Cornelia de Lange and Coffin-Siris syndromes.
2022-11-29 | PXD033446 | Pride
Project description:The DNA-binding protein CTCF and the cohesin complex function together to shape chromatin architecture in mammalian cells, but the molecular details of this process remain unclear. We demonstrate that a 79 amino acid region within the CTCF N-terminal domain but not the C-terminus is necessary for cohesin positioning at CTCF binding sites and chromatin loop formation. However, the N-terminus of CTCF, when fused to artificial zinc fingers that do not bind to CTCF DNA binding sites was not sufficient to redirect cohesin to different genomic locations, indicating that cohesin positioning by CTCF does not involve direct protein-protein interactions with cohesin subunits. BORIS (CTCFL), a germline-specific paralog of CTCF was unable to anchor cohesin to CTCF DNA binding sites. Furthermore, CTCF-BORIS Chimeric constructs provided evidence that both the first two CTCF zinc fingers and, likely, the 3D geometry of CTCF-DNA complexes are involved in cohesin retention. Moreover, we were able to convert BORIS into CTCF with respect to cohesin positioning, thus providing additional molecular details of the cohesin retention function of CTCF. Our data suggest that the N-terminus of CTCF and the 3D spatial conformation of the CTCF-DNA complex act as a roadblock to constrain cohesin movement along DNA.
2020-01-01 | GSE136122 | GEO