Nucleoporin 153 links nuclear pore complex to chromatin architecture by mediating CTCF and cohesin binding [RNA-Seq]
Ontology highlight
ABSTRACT: Establishment of cell lineage specification, maintenance of cellular states and cellular responses to developmental cues rely on gene regulation and spatial genome organization during early development. Emerging data point to highly coordinated activity between epigenetic mechanisms that involve nuclear architecture, chromatin structure and chromatin organization. We show that the nuclear pore complex (NPC) basket protein, Nucleoporin 153 (NUP153) interacts with the nuclear architectural proteins, CTCF and cohesin, and mediates their binding across cis-regulatory elements in pluripotent mouse embryonic stem (ES) cells. NUP153 depletion results in altered occupancy of architectural proteins coupled with differential changes in transcription. This affect is most prevalent at the bivalent genes. To provide molecular insights onto NUP153-mediated gene regulation, we utilized Epidermal Growth Factor (EGF)-inducible immediate early gene (IEG) loci, which we identified as NUP153 targets. IEG transcription is regulated through a POL II pause-release mechanism. We provide evidence that NUP153 is critical for CTCF and cohesin occupancy and subsequent POL II recruitment to the IEG proximal-promoter sites during the paused state. In particular, establishment of a poised IEG chromatin environment relies on co-regulatory function of NUP153 and CTCF, which underlies efficient and timely IEG transcription at the NPC. Our results uncover a key role for the mammalian NPC in distribution of chromatin architectural proteins and demonstrate that NUP153 acts as a cis-acting factor that causally links the NPC to chromatin organization during transcription regulation.
Project description:Establishment of cell lineage specification, maintenance of cellular states and cellular responses to developmental cues rely on gene regulation and spatial genome organization during early development. Emerging data point to highly coordinated activity between epigenetic mechanisms that involve nuclear architecture, chromatin structure and chromatin organization. We show that the nuclear pore complex (NPC) basket protein, Nucleoporin 153 (NUP153) interacts with the nuclear architectural proteins, CTCF and cohesin, and mediates their binding across cis-regulatory elements in pluripotent mouse embryonic stem (ES) cells. NUP153 depletion results in altered occupancy of architectural proteins coupled with differential changes in transcription. This affect is most prevalent at the bivalent genes. To provide molecular insights onto NUP153-mediated gene regulation, we utilized Epidermal Growth Factor (EGF)-inducible immediate early gene (IEG) loci, which we identified as NUP153 targets. IEG transcription is regulated through a POL II pause-release mechanism. We provide evidence that NUP153 is critical for CTCF and cohesin occupancy and subsequent POL II recruitment to the IEG proximal-promoter sites during the paused state. In particular, establishment of a poised IEG chromatin environment relies on co-regulatory function of NUP153 and CTCF, which underlies efficient and timely IEG transcription at the NPC. Our results uncover a key role for the mammalian NPC in distribution of chromatin architectural proteins and demonstrate that NUP153 acts as a cis-acting factor that causally links the NPC to chromatin organization during transcription regulation.
Project description:Precise control of gene expression during differentiation relies on the interplay of chromatin and nuclear structure. Despite an established contribution of nuclear membrane proteins to developmental gene regulation, little is known regarding the role of inner nuclear proteins. Here we demonstrate that loss of the nuclear scaffolding protein Matrin-3 (Matr3) in erythroid cells leads to morphological and gene expression changes characteristic of accelerated maturation, as well as broad alterations in chromatin organization similar to those accompanying differentiation. Matr3 protein interacts with CTCF and the cohesin complex, and its loss perturbs their occupancy at a subset of sites. Destabilization of CTCF and cohesin binding correlates with altered transcription and accelerated differentiation. This association is conserved in embryonic stem cells. Our findings indicate Matr3 negatively affects cell fate transitions and demonstrate that a critical inner nuclear protein impacts occupancy of architectural factors, culminating in broad effects on chromatin organization and cell differentiation.
Project description:To ensure proper gene regulation within constrained nuclear space, chromosomes facilitate access to transcribed regions, while compactly packaging all other information. Recent studies revealed that chromosomes are organized into megabase-scale domains that demarcate active and inactive genetic elements, suggesting that compartmentalization is important for genome function. Here we show that very specific long-range interactions are anchored by cohesin/CTCF sites, but not cohesin-only or CTCF-only sites, to form a hierarchy of chromosomal loops. These loops demarcate topological domains and form intricate internal structures within them. Post-mitotic nuclei deficient for functional cohesin exhibit global architectural changes associated with loss of cohesin/CTCF contacts and relaxation of topological domains. Transcriptional analysis shows that this cohesin-dependent perturbation of domain organization leads to widespread gene deregulation of both cohesin-bound and non-bound genes. Our data thereby support a role for cohesin in the global organization of domain structure and suggest that domains function to stabilize the transcriptional programs within them. Hi-C, ChIP-Seq and RNA-Seq experiments were conducted in mouse neural stem cells and mouse astrocytes
Project description:To ensure proper gene regulation within constrained nuclear space, chromosomes facilitate access to transcribed regions, while compactly packaging all other information. Recent studies revealed that chromosomes are organized into megabase-scale domains that demarcate active and inactive genetic elements, suggesting that compartmentalization is important for genome function. Here we show that very specific long-range interactions are anchored by cohesin/CTCF sites, but not cohesin-only or CTCF-only sites, to form a hierarchy of chromosomal loops. These loops demarcate topological domains and form intricate internal structures within them. Post-mitotic nuclei deficient for functional cohesin exhibit global architectural changes associated with loss of cohesin/CTCF contacts and relaxation of topological domains. Transcriptional analysis shows that this cohesin-dependent perturbation of domain organization leads to widespread gene deregulation of both cohesin-bound and non-bound genes. Our data thereby support a role for cohesin in the global organization of domain structure and suggest that domains function to stabilize the transcriptional programs within them. Hi-C, ChIP-Seq and RNA-Seq experiments were conducted in mouse neural stem cells and mouse astrocytes
Project description:To ensure proper gene regulation within constrained nuclear space, chromosomes facilitate access to transcribed regions, while compactly packaging all other information. Recent studies revealed that chromosomes are organized into megabase-scale domains that demarcate active and inactive genetic elements, suggesting that compartmentalization is important for genome function. Here we show that very specific long-range interactions are anchored by cohesin/CTCF sites, but not cohesin-only or CTCF-only sites, to form a hierarchy of chromosomal loops. These loops demarcate topological domains and form intricate internal structures within them. Post-mitotic nuclei deficient for functional cohesin exhibit global architectural changes associated with loss of cohesin/CTCF contacts and relaxation of topological domains. Transcriptional analysis shows that this cohesin-dependent perturbation of domain organization leads to widespread gene deregulation of both cohesin-bound and non-bound genes. Our data thereby support a role for cohesin in the global organization of domain structure and suggest that domains function to stabilize the transcriptional programs within them. Hi-C, ChIP-Seq and RNA-Seq experiments were conducted in mouse neural stem cells and mouse astrocytes
Project description:The transcription factor CCCTC-binding factor (CTCF) modulates pleiotropic functions mostly related to gene expression regulation. The role of CTCF in large scale genome organization is also well established. A unifying model to explain relationships between many CTCF-mediated activities involve direct or indirect interactions with numerous protein cofactors recruited to specific binding sites. The co-association of CTCF with other architectural proteins such as cohesin, chromodomain helicases and BRG1 further support the interplay between master regulators of mammalian genome folding. Here we report a comprehensive LC-MS/MS mapping of the components of the SWI/SNF chromatin remodeling complex co-associated with CTCF including subunits belonging to the core, signature and ATPase modules. We further show that the localization patterns of representative SWI/SNF members significantly overlap with CTCF sites on transcriptionally active chromatin regions. Moreover, we provide evidence of a direct binding of the BRK-BRG1 domain to the zinc finger motifs 4-8 of CTCF, thus suggesting that these domains mediate the interaction of CTCF with the SWI/SNF complex. These findings provide an updated view of the cooperative nature between CTCF and the SWI/SNF ATP-dependent chromatin-remodeling complexes, an important step for understanding how these architectural proteins collaborate to shape the genome.
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:Cohesin stalling at CTCF binding sites represents one of the main principles of interphase chromosome organization. In the current studies, we dissect the role of cohesin and CTCF, both alone and in combination, in 3D genome organization by depleting these proteins using acute protein degradation techniques. By systematic examination of interactomic, epigenomic and transcriptomic changes using various sequencing techniques, our studies reveal the functions of cohesin and CTCF in mediating the formation of chromatin loops, topologically associating domains, chromosome compartments and nuclear lamina associating domains. Our studies describe fundamental principles of how the architectural proteins contribute to genome folding at multiple genomic scales and transcriptional regulation.
Project description:Cohesin stalling at CTCF binding sites represents one of the main principles of interphase chromosome organization. In the current studies, we dissect the role of cohesin and CTCF, both alone and in combination, in 3D genome organization by depleting these proteins using acute protein degradation techniques. By systematic examination of interactomic, epigenomic and transcriptomic changes using various sequencing techniques, our studies reveal the functions of cohesin and CTCF in mediating the formation of chromatin loops, topologically associating domains, chromosome compartments and nuclear lamina associating domains. Our studies describe fundamental principles of how the architectural proteins contribute to genome folding at multiple genomic scales and transcriptional regulation.
Project description:Cohesin stalling at CTCF binding sites represents one of the main principles of interphase chromosome organization. In the current studies, we dissect the role of cohesin and CTCF, both alone and in combination, in 3D genome organization by depleting these proteins using acute protein degradation techniques. By systematic examination of interactomic, epigenomic and transcriptomic changes using various sequencing techniques, our studies reveal the functions of cohesin and CTCF in mediating the formation of chromatin loops, topologically associating domains, chromosome compartments and nuclear lamina associating domains. Our studies describe fundamental principles of how the architectural proteins contribute to genome folding at multiple genomic scales and transcriptional regulation.