Promoter-proximal CTCF binding promotes distal enhancer-dependent gene activation III
Ontology highlight
ABSTRACT: The CCCTC-binding factor (CTCF) is widely regarded as a key player in chromosome organization in mammalian cells, yet direct assessment of its role in genome architecture and gene regulation has been difficult. Here, we use auxin-inducible degron techniques to acutely deplete CTCF to determine how loss of CTCF affect chromatin organization and gene expression. In mouse embryonic stem cells, depletion of CTCF results in rapid loss of chromatin loops anchored at CTCF-binding sites without major disruption to chromatin compartments and topological domains. In the absence of CTCF, many lineage-specific genes fail to express properly during differentiation to neural precursor cells, but transcriptional regulation of most genes is unaffected. Genes dependent on CTCF for induction are generally bound by the factor at promoters, which are connected to distal enhancers via CTCF-dependent chromatin loops. By contrast, CTCF-independent genes generally lack CTCF binding at the promoter and are generally closer to enhancers. These results refine our understanding of CTCF function in chromatin organization and gene regulation.
Project description:The CCCTC-binding factor (CTCF) is widely regarded as a key player in chromosome organization in mammalian cells, yet direct assessment of its role in genome architecture and gene regulation has been difficult. Here, we use auxin-inducible degron techniques to acutely deplete CTCF to determine how loss of CTCF affect chromatin organization and gene expression. In mouse embryonic stem cells, depletion of CTCF results in rapid loss of chromatin loops anchored at CTCF-binding sites without major disruption to chromatin compartments and topological domains. In the absence of CTCF, many lineage-specific genes fail to express properly during differentiation to neural precursor cells, but transcriptional regulation of most genes is unaffected. Genes dependent on CTCF for induction are generally bound by the factor at promoters, which are connected to distal enhancers via CTCF-dependent chromatin loops. By contrast, CTCF-independent genes generally lack CTCF binding at the promoter and are generally closer to enhancers. These results refine our understanding of CTCF function in chromatin organization and gene regulation.
Project description:The CCCTC-binding factor (CTCF) is widely regarded as a key player in chromosome organization in mammalian cells, yet direct assessment of its role in genome architecture and gene regulation has been difficult. Here, we use auxin-inducible degron techniques to acutely deplete CTCF to determine how loss of CTCF affect chromatin organization and gene expression. In mouse embryonic stem cells, depletion of CTCF results in rapid loss of chromatin loops anchored at CTCF-binding sites without major disruption to chromatin compartments and topological domains. In the absence of CTCF, many lineage-specific genes fail to express properly during differentiation to neural precursor cells, but transcriptional regulation of most genes is unaffected. Genes dependent on CTCF for induction are generally bound by the factor at promoters, which are connected to distal enhancers via CTCF-dependent chromatin loops. By contrast, CTCF-independent genes generally lack CTCF binding at the promoter and are generally closer to enhancers. These results refine our understanding of CTCF function in chromatin organization and gene regulation.
Project description:The CCCTC-binding factor (CTCF) is widely regarded as a key player in chromosome organization in mammalian cells, yet direct assessment of its role in genome architecture and gene regulation has been difficult. Here, we use auxin-inducible degron techniques to acutely deplete CTCF to determine how loss of CTCF affect chromatin organization and gene expression. In mouse embryonic stem cells, depletion of CTCF results in rapid loss of chromatin loops anchored at CTCF-binding sites without major disruption to chromatin compartments and topological domains. In the absence of CTCF, many lineage-specific genes fail to express properly during differentiation to neural precursor cells, but transcriptional regulation of most genes is unaffected. Genes dependent on CTCF for induction are generally bound by the factor at promoters, which are connected to distal enhancers via CTCF-dependent chromatin loops. By contrast, CTCF-independent genes generally lack CTCF binding at the promoter and are generally closer to enhancers. These results refine our understanding of CTCF function in chromatin organization and gene regulation.
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
Project description:An increasing number of genes involved in chromatin structure and epigenetic regulation has been implicated in a variety of developmental disorders, often including intellectual disability. By trio exome sequencing and subsequent mutational screening we now identified two de novo frameshift mutations and one de novo missense mutation in the CTCF gene in individuals with intellectual disability, microcephaly and growth retardation. Furthermore, a patient with a larger deletion including CTCF was identified. CTCF (CCCTC-binding factor) is one of the most important chromatin organizers in vertebrates and is involved in various chromatin regulation processes such as higher order of chromatin organization, enhancer function, and maintenance of three-dimensional chromatin structure. Transcriptome analyses in all three patients with point mutations revealed deregulation of genes involved in signal transduction and emphasized the role of CTCF in enhancer-driven expression of genes. Our findings indicate that haploinsufficiency of CTCF affects genomic interaction of enhancers and their regulated gene promoters that drive developmental processes and cognition. ChIP-seq analysis of CTCF genomic binding sites in lymphocytes of a control individual (no replicates).
Project description:An increasing number of genes involved in chromatin structure and epigenetic regulation has been implicated in a variety of developmental disorders, often including intellectual disability. By trio exome sequencing and subsequent mutational screening we now identified two de novo frameshift mutations and one de novo missense mutation in the CTCF gene in individuals with intellectual disability, microcephaly and growth retardation. Furthermore, a patient with a larger deletion including CTCF was identified. CTCF (CCCTC-binding factor) is one of the most important chromatin organizers in vertebrates and is involved in various chromatin regulation processes such as higher order of chromatin organization, enhancer function, and maintenance of three-dimensional chromatin structure. Transcriptome analyses in all three patients with point mutations revealed deregulation of genes involved in signal transduction and emphasized the role of CTCF in enhancer-driven expression of genes. Our findings indicate that haploinsufficiency of CTCF affects genomic interaction of enhancers and their regulated gene promoters that drive developmental processes and cognition. Comparison of lymphocyte gene expression between 3 de novo CTCF mutation patients and 8 controls (4 technical replicates each, no biological replicates).
Project description:CCCTC-binding factor (CTCF) is essential for chromatin organization, but its role in dynamically shaping chromatin loops during cellular differentiation is not fully understood. We previously demonstrated that CTCF interacts with endogenous RNAs, and deletion of its ZF1 RNA-binding region disrupts chromatin loops in mouse embryonic stem cells (ESCs). Using an ESC-to-neural progenitor cell (NPC) differentiation model, we show that the ZF1 RNA-binding region of CTCF is crucial for maintaining cell-type specific chromatin loops. Expression of CTCF-∆ZF1 leads to dysregulation of genes within these disrupted loops, particularly those involved in neuronal development and function. We identified NPC-specific, CTCF-interacting RNAs and chose Podxl and Grb10 for further study. We found that CRISPR-Cas9-mediated truncation of Podxl and Grb10 disrupts chromatin loops in cis, similar to the disruption seen in the NPC-∆ZF1 mutant. Our study underscores the importance of CTCF-ZF1 RNA interactions in preserving cell-specific genome structure and cellular identity.
Project description:CCCTC-binding factor (CTCF) is essential for chromatin organization, but its role in dynamically shaping chromatin loops during cellular differentiation is not fully understood. We previously demonstrated that CTCF interacts with endogenous RNAs, and deletion of its ZF1 RNA-binding region disrupts chromatin loops in mouse embryonic stem cells (ESCs). Using an ESC-to-neural progenitor cell (NPC) differentiation model, we show that the ZF1 RNA-binding region of CTCF is crucial for maintaining cell-type specific chromatin loops. Expression of CTCF-∆ZF1 leads to dysregulation of genes within these disrupted loops, particularly those involved in neuronal development and function. We identified NPC-specific, CTCF-interacting RNAs and chose Podxl and Grb10 for further study. We found that CRISPR-Cas9-mediated truncation of Podxl and Grb10 disrupts chromatin loops in cis, similar to the disruption seen in the NPC-∆ZF1 mutant. Our study underscores the importance of CTCF-ZF1 RNA interactions in preserving cell-specific genome structure and cellular identity.
Project description:CCCTC-binding factor (CTCF) is essential for chromatin organization, but its role in dynamically shaping chromatin loops during cellular differentiation is not fully understood. We previously demonstrated that CTCF interacts with endogenous RNAs, and deletion of its ZF1 RNA-binding region disrupts chromatin loops in mouse embryonic stem cells (ESCs). Using an ESC-to-neural progenitor cell (NPC) differentiation model, we show that the ZF1 RNA-binding region of CTCF is crucial for maintaining cell-type specific chromatin loops. Expression of CTCF-∆ZF1 leads to dysregulation of genes within these disrupted loops, particularly those involved in neuronal development and function. We identified NPC-specific, CTCF-interacting RNAs and chose Podxl and Grb10 for further study. We found that CRISPR-Cas9-mediated truncation of Podxl and Grb10 disrupts chromatin loops in cis, similar to the disruption seen in the NPC-∆ZF1 mutant. Our study underscores the importance of CTCF-ZF1 RNA interactions in preserving cell-specific genome structure and cellular identity.
Project description:CCCTC-binding factor (CTCF) is essential for chromatin organization, but its role in dynamically shaping chromatin loops during cellular differentiation is not fully understood. We previously demonstrated that CTCF interacts with endogenous RNAs, and deletion of its ZF1 RNA-binding region disrupts chromatin loops in mouse embryonic stem cells (ESCs). Using an ESC-to-neural progenitor cell (NPC) differentiation model, we show that the ZF1 RNA-binding region of CTCF is crucial for maintaining cell-type specific chromatin loops. Expression of CTCF-∆ZF1 leads to dysregulation of genes within these disrupted loops, particularly those involved in neuronal development and function. We identified NPC-specific, CTCF-interacting RNAs and chose Podxl and Grb10 for further study. We found that CRISPR-Cas9-mediated truncation of Podxl and Grb10 disrupts chromatin loops in cis, similar to the disruption seen in the NPC-∆ZF1 mutant. Our study underscores the importance of CTCF-ZF1 RNA interactions in preserving cell-specific genome structure and cellular identity.