Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

SMARCA4 Rescue Profiling [RNA]

ABSTRACT: Mutations in SMARCA4, a central ATPase of the human BAF/PBAF chromatin remodeling complexes, cause developmental abnormalities and promote cancer development. The pathogenic effects of SMARCA4 loss are often linked to the de-regulation of a relatively small number of key target genes. Here, to understand how chromatin remodeling by SMARCA4 results in specific transcriptional perturbations, we used genome engineering to correct a homozygous mutation in SMARCA4 in the well-characterized lung adenocarcinoma A549 cell line and profiled changes in SMARCA2/4 occupancy, chromatin accessibility, histone marks and transcription. Restoration of SMARCA4 causes a dramatic increase in chromatin accessibility at low affinity TF binding sites. Despite the widespread increase in chromatin accessibility, we observe comparatively attenuated changes in gene expression. Although there is a marked correlation between the number of local activated DHSs and the transcriptional responsivity of a gene, the influence of distal DHSs appears modified by a gene's promoter architecture and domain-scale chromatin organization. The largest changes in expression occur for genes in isolated, SMARCA4 sensitive chromatin domains that undergo region-wide chromatin remodeling upon reintroduction of SMARCA4. Our results reveal that interactions between distal enhancers, genome organization, and promoter architecture add transcriptional specificity to the global chromatin effects of BAF/PBAF complex perturbation and target the response to key developmental pathways.

ORGANISM(S): Homo sapiens

PROVIDER: GSE132291 | GEO | 2020/05/20

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

SMARCA4 Rescue Profiling [Dnase]

Project description:Mutations in SMARCA4, a central ATPase of the human BAF/PBAF chromatin remodeling complexes, cause developmental abnormalities and promote cancer development. The pathogenic effects of SMARCA4 loss are often linked to the de-regulation of a relatively small number of key target genes. Here, to understand how chromatin remodeling by SMARCA4 results in specific transcriptional perturbations, we used genome engineering to correct a homozygous mutation in SMARCA4 in the well-characterized lung adenocarcinoma A549 cell line and profiled changes in SMARCA2/4 occupancy, chromatin accessibility, histone marks and transcription. Restoration of SMARCA4 causes a dramatic increase in chromatin accessibility at low affinity TF binding sites. Despite the widespread increase in chromatin accessibility, we observe comparatively attenuated changes in gene expression. Although there is a marked correlation between the number of local activated DHSs and the transcriptional responsivity of a gene, the influence of distal DHSs appears modified by a gene's promoter architecture and domain-scale chromatin organization. The largest changes in expression occur for genes in isolated, SMARCA4 sensitive chromatin domains that undergo region-wide chromatin remodeling upon reintroduction of SMARCA4. Our results reveal that interactions between distal enhancers, genome organization, and promoter architecture add transcriptional specificity to the global chromatin effects of BAF/PBAF complex perturbation and target the response to key developmental pathways.

2020-05-20 | GSE132292 | GEO

SMARCA4 Rescue Profiling [ChIP]

2020-05-20 | GSE132290 | GEO

Acute BAF perturbation causes immediate changes in chromatin accessibility

Project description:Loss-of-function mutations in genes coding for subunits of the large, multifarious BRG1/BRM associated factor (BAF) chromatin remodeling complexes are frequently causative for cancer or developmental diseases1-5. Cells lacking the most frequently mutated subunits like the ATPase SMARCA4 typically exhibit drastic chromatin accessibility changes, especially of important regulatory regions6-12. However, so far it remains unknown how these changes are established over time, and whether they are causative for intra-complex synthetic lethalities abrogating the formation (SMARCC1-SMARCC2)8,13,14 or activity (SMARCA4-SMARCA2)15-17 of BAF complexes. Here, we utilize the dTAG system18 to induce acute degradation of BAF subunits in wild-type and BAF mutant backgrounds and analyze the resulting chromatin accessibility changes with high kinetic resolution. We observe that chromatin alterations are established faster than the duration of one cell cycle and that maintaining genome accessibility requires constant ATP-dependent remodeling. Completely abolishing BAF complex function by acute degradation of a synthetic lethal subunit in a paralog-deficient background results in a near-complete loss of chromatin accessibility at BAF-controlled sites, especially at super-enhancers, providing a mechanism for intra-complex synthetic lethalities.

2020-12-23 | PXD018381 | Pride

A structural model of the human mSWI/SNF (BAF) complex bound to the nucleosome informs disease mechanisms

Project description:Mammalian SWI/SNF complexes are multi-component ATP-dependent chromatin-remodeling complexes that regulate genomic architecture. Here we present the first structural model of the human canonical BAF chromatin-remodeling complex bound to a nucleosome generated using cryo-EM, cross-linking mass spectrometry, and homology modeling. Endogenously-purified BAF tethers to the nucleosome H2A/H2B acidic patch regions bilaterally through the SMARCB1 C-terminal helix and a SMARCA4 C-terminal post-SnAc region, each of which are mutated in disease and disrupt nucleosome remodeling. We describe the structural organization of the BAF core module, a connecting ARP module and the ATPase module, scaffolded by the SMARCA4/2 ATPase subunits. Importantly, we assign and model disease-associated mutations throughout the entire BAF complex, identifying mutations that break identified subunit–nucleosome contacts and subunit–subunit interfaces of BAF in the nucleosome-bound conformation. Taken together, this comprehensive structural model of the human BAF complex provides the first insights into the functional impact of mutations that cause cancer and other diseases.

2021-02-10 | PXD020992 | Pride

Systematic characterization of BAF mutations explains intra-complex synthetic lethalities

Project description:Aberrations in genes coding for subunits of the BAF chromatin remodeling complex are highly abundant in human cancers. Currently, it is not understood how these loss-of-function mutations contribute to cancer development and how they can be targeted therapeutically. The cancer type specific occurrence patterns of certain subunit mutations suggest subunit-specific effects on BAF complex function, possibly by the formation of aberrant residual complexes. Here, we systematically characterize the effects of individual subunit loss on complex composition, chromatin accessibility and gene expression in a panel of knock-out cell lines deficient for 22 targetable BAF subunits. We observe strong, specific and often discordant alterations dependent on the targeted subunit and show that these explain intra-complex co-dependencies, including the novel synthetic lethal interactions SMARCA4-ARID2, SMARCA4-ACTB and SMARCC1-SMARCC2. These data provide insights into the role of different BAF subcomplexes in genome-wide chromatin organization and suggest novel approaches to therapeutically target BAF mutant cancers.

2019-08-01 | PXD013102 | Pride

Structure of nucleosome-bound human PBAF complex

Project description:BAF and PBAF are mammalian SWI/SNF family chromatin remodeling complexes that possess multiple histone/DNA-binding subunits and create nucleosome-depleted/free regions for transcription activation. Despite previous structural studies and recent advance of SWI/SNF family complexes, it remains incompletely understood how PBAF-nucleosome complex is organized. Here we determined structure of 13-subunit human PBAF in complex with acetylated nucleosome in ADP-BeF3-bound state. Four PBAF-specific subunits work together with nine BAF/PBAF-shared subunits to generate PBAF-specific modular organization, distinct from that of BAF at various regions. PBAF-nucleosome structure reveals six histone-binding domains and four DNA-binding domains/modules, the majority of which directly bind histone/DNA. This multivalent nucleosome-binding pattern, not observed in previous studies, suggests that PBAF may integrate comprehensive chromatin information to target genomic loci for function. Our study reveals molecular organization of subunits and histone/DNA-binding domains/modules in PBAF-nucleosome complex and provides structural insights into PBAF-mediated nucleosome association complimentary to the recently reported PBAF-nucleosome structure.

2023-03-11 | PXD036708 | Pride

Human pBAF complex (HA-BRD7, PHF10-HA pulldown)

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

Drosophila BAF complex crosslinking (

2018-10-18 | PXD010123 | Pride

Single-minded homolog 2 resides in the chromatin protein network of androgen receptor and modulates gene expression in prostate cancer cells Single-minded homolog 2 resides in the chromatin protein network of androgen receptor and modulates gene expression in prostate cancer cells

Project description:We investigated the composition of chromatin protein network around endogenous androgen receptor (AR) in VCaP castration resistant prostate cancer cells using recently developed chromatin-directed proteomic approach called ChIP-SICAP . The androgen-induced AR chromatin protein network contained expected TFs, e.g. HOXB13, chromatin remodeling proteins, e.g. SMARCA4, and several novel candidates not previously associated with AR, e.g. prostate cancer biomarker SIM2. Based on these findings, the role of SMARCA4 and SIM2 was further characterized at AR chromatin domains . Silencing of SIM2 altered chromatin accessibility at a similar number of AR-binding sites as SMARCA4, an established ATPase subunit of the BAF chromatin remodeling complex, often aberrantly expressed in prostate cancer. Despite the wide co-occurrence on chromatin of SMARCA4 and AR, depletion of SMARCA4 influenced chromatin accessibility and expression of a restricted set of AR target genes, in particular those involved in cell morphogenetic changes in epithelial-mesenchymal transition. Silencing of SIM2, in turn, affected the expression of a much larger group of androgen-regulated genes, e.g. those involved in cellular responses to external stimuli and steroid hormone stimulus. The silencing also reduced proliferation of VCaP cells and tumor size in chick embryo chorioallantoic membrane assay, further suggesting the importance of SIM2 in the regulation prostate cancer cells.

2021-06-17 | PXD025193 | Pride

Distinct SWI/SNF chromatin remodelling complexes act differentially to maintain stem-like exhausted CD8 T cells [RNA-seq]

Project description:Exhausted CD8 T cells (TEX) arise during chronic viral infections and cancer and limit disease control. Three major sequential epigenetic remodeling events occur as naïve CD8 T cells (TN) differentiate into TEX: initial activation, early bifurcation between effector (TEFF) and TEX precursors, and later differentiation of effector-like and terminal TEX subsets from progenitor TEX. The epigenetic factors mediating these transitions remain poorly understood. Here, we uncovered distinct roles for two versions of the SWI/SNF chromatin remodeling complex, BAF and PBAF, in TEX differentiation using in vivo CRISPR screening. Disruption of BAF ablated antigen-specific CD8 T cells early in chronic infection, suggesting a requirement for BAF-mediated remodeling in the early epigenetic remodeling events. In contrast, depletion of PBAF subunits enhanced TEX formation and promoted progenitor TEX differentiation into more differentiated TEX subsets by limiting accessibility of TCF-1 binding sites. Loss of PBAF improved tumor control alone and in combination with anti-PD-L1. Simultaneous depletion of BAF- and PBAF-specific subunits revealed that BAF is required for the beneficial impact of loss of PBAF on TEX differentiation. Thus, BAF and PBAF regulate epigenetic transitions in CD8 T cell differentiation, with PBAF acting at a later stage in exhaustion as a guardian to limit full TEX differentiation and preserve TEX progenitor populations with implications for cancer immunotherapy.

2023-05-31 | GSE211410 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data