Structural and functional properties of mSWI/SNF chromatin remodeling complexes revealed through single-cell perturbation and genomic profiling
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE200201 | GEO | 2023/04/05
REPOSITORIES: GEO
Similar Datasets
Project description:Mammalian SWI/SNF (mSWI/SNF) ATP-dependent chromatin remodeling complexes are large, multisubunit molecular machines that play vital roles in regulating genomic architecture and are frequently disrupted in human cancer and developmental disorders. To date, the organization and pathway of assembly of these chromatin regulators remain unknown, presenting a major barrier to structural and functional determination. Here we elucidate the architecture and assembly pathway of three different classes of mammalian SWI/SNF complexes: canonical BAF, PBAF, and a newly defined complex, ncBAF, and define the requirement of each subunit for complex formation and stability. Using affinity purification of endogenous complexes from mammalian and Drosophila cells coupled with cross linking-mass spectrometry, we uncover three distinct and evolutionarily conserved modules, their organization, and the temporal incorporation of these modules into each complete mSWI/SNF complex class.
2018-10-18 | PXD010122 | Pride
Project description:Mammalian SWI/SNF (mSWI/SNF) ATP-dependent chromatin remodeling complexes are large, multisubunit molecular machines that play vital roles in regulating genomic architecture and are frequently disrupted in human cancer and developmental disorders. To date, the organization and pathway of assembly of these chromatin regulators remain unknown, presenting a major barrier to structural and functional determination. Here we elucidate the architecture and assembly pathway of three different classes of mammalian SWI/SNF complexes: canonical BAF, PBAF, and a newly defined complex, ncBAF, and define the requirement of each subunit for complex formation and stability. Using affinity purification of endogenous complexes from mammalian and Drosophila cells coupled with cross linking-mass spectrometry, we uncover three distinct and evolutionarily conserved modules, their organization, and the temporal incorporation of these modules into each complete mSWI/SNF complex class.
2018-10-18 | PXD010123 | Pride
Project description:Increased cortical size is essential to the enhanced intellectual capacity of primates during mammalian evolution. The mechanisms that control cortical size are largely unknown. Here, we show that mammalian BAF170, a subunit of the chromatin remodeling complex mSWI/SNF, is an intrinsic factor that controls cortical size. We find that the conditional deletion of BAF170 promotes indirect neurogenesis by increasing the pool of intermediate progenitors (IPs) and results in an enlarged cortex, whereas cortex-specific BAF170 over-expression results an opposing phenotype. Mechanistically, BAF170 competes with BAF155 subunit in the BAF complex, affecting the euchromatin structure and thereby modulating the binding efficiency of Pax6/REST-corepressor complex to Pax6 target genes that regulate the generation of IPs and late cortical progenitors. Our findings reveal a molecular mechanism mediated by the mSWI/SNF chromatin-remodeling complex that controls cortical architecture. Cortical gene expression is compared between three E12.5 mouse embryos with cortex-specific loss of BAF170 function and three littermate control embryos.
2013-05-02 | E-GEOD-45629 | biostudies-arrayexpress
Project description:Rhabdomyosarcoma (RMS) is a highly malignant pediatric cancer of skeletal muscle lineage. The aggressive alveolar subtype is commonly characterized by t(2;13) or t(1;13) translocations with the expression of PAX3- or PAX7-FOXO1 fusion transcription factors respectively and is known as fusion positive RMS (FP-RMS). FP-RMS tumors rely on the fusion gene to maintain their proliferative state while avoiding terminal differentiation program. Since disruptions of normal development are likely governed by epigenetic changes in these low-mutational-burden tumors, we investigated the contributions of chromatin regulatory complexes to RMS tumor maintenance. We demonstrate the essentiality of the mSWI/SNF ATPase BRG1 for FP-RMS proliferation and discover that RMS significantly overexpress SMARCA4 (encoding BRG1) compared to skeletal muscle. We define the mSWI/SNF subunit repertoire in FP-RMS and provide evidence for the assembly of multiple mSWI/SNF complexes including canonical BAF, PBAF and non-canonical (nc)BAF in FP-RMS. Proteomic studies suggest proximity between PAX3-FOXO1 and BAF complexes, which was further supported by genome-wide binding profiles revealing enhancer colocalization of BAF with FP-RMS core regulatory transcription factors. We report that mSWI/SNF complexes act as sensors of chromatin state, which are recruited to sites of de novo histone acetylation. Phenotypically, interference with mSWI/SNF complex function induces transcriptional activation of the skeletal muscle differentiation program associated with MYCN enhancer invasion at myogenic target genes. Finally, BRG1 targeting compounds reproduce the effects of genetic ablation. We conclude that inhibition of BRG1 overcomes the differentiation blockade of FP-RMS cells and may provide a therapeutic strategy for treating this lethal childhood tumor.
2021-04-01 | GSE162052 | GEO
Project description:Copper (Cu)-binding transcription factors are emerging as important regulators of gene expression during skeletal muscle differentiation. Our group has shown that the classic Metal Transcription Factor 1, MTF1, works cooperatively with the myogenic factor MyoD to promote skeletal muscle differentiation and ensure viability of murine primary myoblasts. Preliminary evidence showed that MTF1 interacts with members of the mammalian SWItch/Sucrose Non-Fermentable (mSWI/SNF) family of ATP-dependent chromatin remodeling enzymes to promote differential gene expression in proliferating and differentiating myoblasts. mSWI/SNF complexes are assembled into three major subfamilies that are distinguished by the presence of mutually exclusive subunits: cBAF (canonical BRG1 or BRM-Associated Factor), PBAF (Polybromo containing BAF), or ncBAF (non-canonical BAF). The mechanisms by which each subfamily contributes to the establishment or function of specific cell lineages are poorly understood. We determined the contributions of the BAF, ncBAF, and PBAF complexes to myoblast proliferation, differentiation, and metal homeostasis via knock-down (KD) of a distinguishing subunit of each complex (Baf250A, Brd9, and Baf180, respectively). Biochemical, molecular and RNA-seq analyses showed that Baf250A KD reduced myoblast proliferation rate and differentiation. Brd9 KD resulted in a minor proliferation defect and a delay in myogenesis. KD of Baf180 and other PBAF-specific subunits did not impact proliferation or differentiation but affected the maintenance of metal homeostasis in myoblasts. The data support a model for differential roles and interactions between MTF1 and a novel category of Cu-binding transcription factors and the SWI/SNF enzymes in the development and homeostasis of the skeletal muscle lineage.
2024-10-26 | GSE253376 | GEO
Project description:Copper (Cu)-binding transcription factors are emerging as important regulators of gene expression during skeletal muscle differentiation. Our group has shown that the classic Metal Transcription Factor 1, MTF1, works cooperatively with the myogenic factor MyoD to promote skeletal muscle differentiation and ensure viability of murine primary myoblasts. Preliminary evidence showed that MTF1 interacts with members of the mammalian SWItch/Sucrose Non-Fermentable (mSWI/SNF) family of ATP-dependent chromatin remodeling enzymes to promote differential gene expression in proliferating and differentiating myoblasts. mSWI/SNF complexes are assembled into three major subfamilies that are distinguished by the presence of mutually exclusive subunits: cBAF (canonical BRG1 or BRM-Associated Factor), PBAF (Polybromo containing BAF), or ncBAF (non-canonical BAF). The mechanisms by which each subfamily contributes to the establishment or function of specific cell lineages are poorly understood. We determined the contributions of the BAF, ncBAF, and PBAF complexes to myoblast proliferation, differentiation, and metal homeostasis via knock-down (KD) of a distinguishing subunit of each complex (Baf250A, Brd9, and Baf180, respectively). Biochemical, molecular and RNA-seq analyses showed that Baf250A KD reduced myoblast proliferation rate and differentiation. Brd9 KD resulted in a minor proliferation defect and a delay in myogenesis. KD of Baf180 and other PBAF-specific subunits did not impact proliferation or differentiation but affected the maintenance of metal homeostasis in myoblasts. The data support a model for differential roles and interactions between MTF1 and a novel category of Cu-binding transcription factors and the SWI/SNF enzymes in the development and homeostasis of the skeletal muscle lineage.
2024-10-26 | GSE253377 | GEO
Project description:Brg-or Brm-associated factor (BAF) complexes, is a 12 subunit complex which contains an ATPase subunit, Brg or Brm, that uses energy derived from ATP hydrolysis to disrupt histone:DNA contacts to catalyze transcriptional events such as promoting gene expression or repression. Genetic studies in mice demonstrated that BAF complexes are essential for early embryonic development and pluripotency. ES cells express distinctive compleses, termed esBAF complexes by the presence of BAF155, Brg, BAF60a. Purification of Brg and Brm-associated proteins reveals a new family of four stoichiometric subunits of mSWI/SNF or BAF complexes which was termed BAF45a, b, c, and d. The progenitors to both neurons and glia are maintained in a proliferative state by a specified SWI/SNF-like npBAF complex that contains both BAF45a and BAF53a. The transition from proliferative to neurogenic divisions requires the exchange of these subunites for the homologous BAF45b or BAF45c and BAF53b proteins. The function of BAF45d remwains unclear so far.At present, we found that the knockout of dpf2 in ES cells impared the differention of ES cells. We will identify the target genes of dpf2 by Chip-seq so that we could study how dpf2 affect the differentiation of ES cells into germ layers.Protocol: DNA was prepared from ES cells by standard ChIP method. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
2013-09-30 | E-ERAD-24 | biostudies-arrayexpress
Project description:Rhabdomyosarcoma (RMS) is a highly malignant pediatric cancer of skeletal muscle lineage. The aggressive alveolar subtype is commonly characterized by t(2;13) or t(1;13) translocations with the expression of PAX3- or PAX7-FOXO1 fusion transcription factors respectively and is known as fusion positive RMS (FP-RMS). FP-RMS tumors rely on the fusion gene to maintain their proliferative state while avoiding terminal differentiation program. Since disruptions of normal development are likely governed by epigenetic changes in these low-mutational-burden tumors, we investigated the contributions of chromatin regulatory complexes to RMS tumor maintenance. We demonstrate the essentiality of the mSWI/SNF ATPase BRG1 for FP-RMS proliferation and discover that RMS significantly overexpress SMARCA4 (encoding BRG1) compared to skeletal muscle. We define the mSWI/SNF subunit repertoire in FP-RMS and provide evidence for the assembly of multiple mSWI/SNF complexes including canonical BAF, PBAF and non-canonical (nc)BAF in FP-RMS. Proteomic studies suggest proximity between PAX3-FOXO1 and BAF complexes, which was further supported by genome-wide binding profiles revealing enhancer colocalization of BAF with FP-RMS core regulatory transcription factors. We report that mSWI/SNF complexes act as sensors of chromatin state, which are recruited to sites of de novo histone acetylation. Phenotypically, interference with mSWI/SNF complex function induces transcriptional activation of the skeletal muscle differentiation program associated with MYCN enhancer invasion at myogenic target genes. Finally, BRG1 targeting compounds reproduce the effects of genetic ablation. We conclude that inhibition of BRG1 overcomes the differentiation blockade of FP-RMS cells and may provide a therapeutic strategy for treating this lethal childhood tumor.
2020-11-20 | MSV000086494 | MassIVE
Project description:Recent exon sequencing studies of human tumors have revealed that subunits of mSWI/SNF or BAF complexes are mutated in more than 20% of human malignancies, yet the mechanisms involved in tumor suppression is unclear. BAF chromatin remodeling complexes are polymorphic assemblies that use energy provided by ATP hydrolysis to regulate transcription through the control of chromatin structure and the placement of Polycomb (PcG) across the genome. Several proteins dedicated to this large multi-subunit complex, including SMARCA4 (BRG1) and BAF250A (ARID1A), are mutated at frequencies similar to that of many recognized tumor suppressors. In particular, the core ATPase BRG1 is mutated in 5-10% of childhood medulloblastoma (MB) and greater than 15% of Burkitt's Lymphoma (BL). Here we find a novel function of BAF complexes in decatenating newly replicated sister chromatids, which is necessary for proper chromosome segregation during mitosis. We find that deletion of Brg1, as well as the expression of Brg1 point mutants identified in human tumors leads to anaphase bridge formation (sister chromatids linked by catenated strands of DNA), and a G2/M phase block characteristic of the decatenation checkpoint. Endogenous BAF complexes directly interact with endogenous TopoIIα through BAF250a and are required for TopoIIα binding to about 12,000 sites over the genome. Our results indicate that TopoIIα’s chromatin binding is dependent on the ATPase activity of Brg1, which is compromised in oncogenic Brg1 mutants. These studies indicate that the ability of TopoIIα to prevent DNA entanglement at mitosis requires BAF complexes and suggest that this activity contributes to the role of BAF subunits as tumor suppressors. Examination of sites of TopoIIa activity in WT and Brg1-/- ES cells as defined by TopoIIa-DNA covalent adducts formed in the presence of etoposide
2013-03-30 | E-GEOD-45625 | biostudies-arrayexpress
Project description:Small cell lung cancers (SCLC) are comprised of heterogeneous subtypes marked by lineage-specific transcription factors, including ASCL1, NEUROD1, and POU2F3. POU2F3-positive SCLC, ~12% of all cases, are uniquely dependent on POU2F3 itself; as such, approaches to attenuate POU2F3 expression may represent new therapeutic opportunities for this subtype. Here using genome-scale CRISPR/Cas9-based screens reporting on POU2F3 expression in SCLC cell lines, we define mSWI/SNF complexes, including non-canonical BAF complexes (ncBAF), as top regulators of POU2F3 and dependencies specific to the POU2F3-positive subtype. Notably, clinical-grade pharmacologic mSWI/SNF complex inhibition attenuates proliferation of all POU2F3-positive SCLCs, while disruption of ncBAF via BRD9 degradation is uniquely effective in pure non-neuroendocrine POU2F3-SCLCs. mSWI/SNF complexes maintain accessibility over gene loci central to POU2F3-mediated gene regulatory networks. Finally, chemical targeting of SMARCA4/2 mSWI/SNF ATPases and BRD9 decrease POU2F3-SCLC tumor growth and increase survival in vivo. Taken together, these results define mSWI/SNF-mediated global governance of the POU2F3 oncogenic program and suggest mSWI/SNF inhibition as a therapeutic strategy in SCLC.
2024-06-14 | GSE249258 | GEO