CTCF/cohesin-binding sites mutated in cancer
Ontology highlight
ABSTRACT:
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR906805.fastq.gz | Fastqsanger.gz | |||
| ERR906806.fastq.gz | Fastqsanger.gz | |||
| ERR906807.fastq.gz | Fastqsanger.gz | |||
| ERR906808.fastq.gz | Fastqsanger.gz | |||
| ERR906809.fastq.gz | Fastqsanger.gz |
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Project description:Cohesin is present in almost all active enhancer regions, where it is associated with transcription factors. Cohesin frequently colocalizes with CTCF (CCCTC-binding factor), affecting genomic stability, expression and epigenetic homeostasis. Cohesin subunits are mutated in cancer, but CTCF/cohesin-binding sites (CBSs) in DNA have not been examined for mutations. Here we report frequent mutations at CBSs in cancers displaying a mutational signature where mutations in A•T base pairs predominate. Integration of whole-genome sequencing data from 213 colorectal cancer (CRC) samples and chromatin immunoprecipitation sequencing (ChIP-exo) data identified frequent point mutations at CBSs. In contrast, CRCs showing an ultramutator phenotype caused by defects in the exonuclease domain of DNA polymerase ɛ (POLE) displayed significantly fewer mutations at and adjacent to CBSs. Analysis of public data showed that multiple cancer types accumulate CBS mutations. CBSs are a major mutational hotspot in the noncoding cancer genome.
| EGAS00001003010 | EGA
Project description:CTCF binding sites are frequently mutated in cancer, but how these mutations accumulate and whether they broadly perturb CTCF binding is not well understood. We report that skin cancers exhibit a highly-specific asymmetric mutation pattern within CTCF motifs attributable to ultraviolet irradiation and differential nucleotide excision repair (NER). CTCF binding site mutations form independent of replication timing and are enriched at sites of CTCF/cohesin complex binding, suggesting a role for cohesin in stabilizing CTCF-DNA binding and impairing NER. Performing CTCF ChIP-seq in a melanoma cell-line, we show CTCF binding site mutations to be functional by demonstrating allele-specific reduction of CTCF binding to mutant alleles. While topologically-associating domains with mutated CTCF anchors in melanoma contain differentially-expressed cancer-associated genes, CTCF motif mutations appear generally under neutral selection. However, the frequency and potential functional impact of such mutations in melanoma highlights the need to consider their impact on cellular phenotype in individual genomes.
2016-12-13 | GSE81945 | GEO
Project description:ChIP-seq for CTCF and Rad21 in 3 week old mouse brain from reciprocal BxC and CxB crosses. One biological replicate of each. Examination of CTCF and Cohesin binding sites in neonetal mouse brain
2013-06-20 | E-GEOD-35140 | biostudies-arrayexpress
Project description:Identification of cohesin (Rad21) and CTCF binding sites in ~2% of the mouse genome in B3 pre-B cells stably expressing FLAG-tagged Rad21 using anti-FLAG (Sigma F3165) and anti-CTCF (Upstate 07729) antibodies
2008-01-31 | E-TABM-401 | biostudies-arrayexpress
Project description:Mammalian chromosomes are partitioned into topologically associating domains (TADs) by the loop-extrusion activity of cohesin that is blocked at specific DNA sites bound by CTCF. Chromosome structure inside TADs is highly variable in single cells, yet little is known about its temporal dynamics, how it influences the rates and durations of chromosomal contacts, and how it depends on CTCF and cohesin. To address these questions we combine two quantitative live-cell imaging strategies that minimize locus-specific confounding effects. We show that loop extrusion by cohesin globally reduces the mobility of the chromatin fiber in living cells, while also increasing the rates of formation and durations of contacts between sequences inside the same TAD. Quantitative analysis of high-resolution microscopy data reveals that contacts assemble and disassemble frequently in the course of the cell cycle, and become substantially more frequent and longer in the presence of convergent CTCF sites. Comparison with polymer modeling additionally reveals that cohesin-mediated CTCF loops last around 10 minutes on average. Our data support the notion that chromosome structure within TADs is highly dynamic and provide a quantitative framework for understanding the principles that link chromosome structure to biological function.
2022-02-27 | GSE197237 | 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:Recent studies of genome-wide chromatin interactions have revealed that the human genome is partitioned into many self-associating topological domains. The boundary sequences are enriched for binding sites of CTCF and the cohesin complex, implicating these two factors in the establishment or maintenance of topological domains. To determine the role of cohesin and CTCF in higher order chromatin architecture in human cells, we proteolytically cleaved the cohesin complex from interphase chromatin and examined changes in chromosomal organization as well as transcriptome. We observed a general loss of local chromosomal interactions upon disruption of cohesin complex, but the topological domains remain intact. However, we found that depletion of CTCF by RNA interference in these cells not only reduced intra-domain interactions but also increased inter-domain interactions. Further more, distinct groups of genes become mis-regulated upon depletion of cohesin and CTCF. Taken together, these observations suggest that CTCF and cohesin contribute in different ways to chromatin organization and gene regulation. Hi-C and mRNA-seq experiments in Cohesin and CTCF depleted HEK293 cells
2013-12-16 | E-GEOD-44267 | biostudies-arrayexpress
Project description:CCCTC-binding factor (CTCF) is an architectural protein involved in the three-dimensional organization of chromatin. In this study, we systematically assayed the 3D genomic contact profiles of hundreds of CTCF binding sites in multiple tissues with high-resolution 4C-seq. We find both developmentally stable and dynamic chromatin loops. As recently reported, our data also suggest that chromatin loops preferentially form between CTCF binding sites oriented in a convergent manner. To directly test this, we used CRISPR-Cas9 genome editing to delete core CTCF binding sites in three loci, including the CTCF site in the Sox2 super-enhancer. In all instances, CTCF and cohesin recruitment were lost, and chromatin loops with distal CTCF sites were disrupted or destabilized. Re-insertion of oppositely oriented CTCF recognition sequences restored CTCF and cohesin recruitment, but did not re-establish chromatin loops. We conclude that CTCF binding polarity plays a functional role in the formation of higher order chromatin structure. 4C-seq was performed on a large number of viewpoints in E14 embryonic stem cells, neural precursor cells and primary fetal liver cells
2015-10-29 | E-GEOD-72539 | biostudies-arrayexpress
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
Project description:Cohesin catalyses the folding of the genome into loops that are anchored by CTCF. The molecular mechanism of how cohesin and CTCF structure the 3D genome has remained unclear. Here we show that a segment within the CTCF N terminus interacts with the SA2-SCC1 subunits of cohesin. A 2.6 Å crystal structure of SA2-SCC1 in complex with CTCF reveals the molecular basis of the interaction. We demonstrate that this interaction is specifically required for CTCF-anchored loops and contributes to the positioning of cohesin at CTCF-binding sites. A similar motif is present in a number of established and novel cohesin ligands, including the cohesin release factor WAPL. Our data suggest that CTCF enables chromatin loop formation by protecting cohesin against loop release. These results provide fundamental insights into the molecular mechanism that enables dynamic regulation of chromatin folding by cohesin and CTCF.
2020-01-07 | GSE126636 | GEO