Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA322402 | ENA |
REPOSITORIES: ENA
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Project description:The composition of chromatin remodeling complexes dictates how these enzymes control transcriptional programs and cellular identity. Here, we investigate the composition of SWI/SNF complexes in embryonic stem cells (ESCs). In contrast to differentiated cells, ESCs have a biased incorporation of certain paralogous SWI/SNF subunits, with low levels of Brm, BAF170 and ARID1B. Upon differentiation, the expression of these subunits increases, resulting in a higher diversity of compositionally distinct SWI/SNF enzymes. We also identify Brd7 as a novel component of the PBAF complex in both ESCs and differentiated cells. Using shRNA-mediated depletion of Brg1, we show that SWI/SNF can function as both a repressor and an activator in pluripotent cells, regulating expression of developmental modifiers and signaling components such as Nodal, ADAMTS1, Bmi-1, CRABP1 and TRH. Knock-down studies of PBAF-specific Brd7 and of a signature subunit within the BAF complex, ARID1A, show that these two sub-complexes affect SWI/SNF target genes differentially, in some cases even antagonistically. This may be due to their different biochemical properties. Finally, we examine the role of SWI/SNF in regulating its target genes during differentiation. We find that SWI/SNF affects recruitment of components of the pre-initiation complex in a promoter-specific manner, to modulate transcription positively or negatively. Taken together, our results provide insight into the function of compositionally diverse SWI/SNF enzymes that underlie their inherent gene-specific mode of action. R1 ESCs were infected in duplicates with shRNA targeting Brg1 or GLUT4 (as a control). Knockdown of Brg1 mRNA affected Brg1 protein levels efficiently. RNA was isolated 67 hours post-infection and analyzed using microarrays.
2010-03-04 | E-GEOD-7791 | biostudies-arrayexpress
Project description:Switch defective/sucrose non-fermentable (SWI/SNF) complexes are evolutionarily conserved multi-subunit machines that play vital roles in chromatin architecture regulation for modulating gene expression via sliding or ejection of nucleosomes in eukaryotes. In plants, perturbations of SWI/SNF subunits often result in severe developmental disorders. However, the subunit composition, pathways of assembly, and genomic targeting of the plant SWI/SNF complexes remain undefined. Here, we reveal that Arabidopsis SWI/SNF complexes exist in three distinct final form assemblies: BRM-associated SWI/SNF complexes (BAS), SYD-associated SWI/SNF complexes (SAS) and MINU-associated SWI/SNF complexes (MAS). We show that BAS complexes are equivalent to human ncBAF, whereas SAS and MAS complexes evolve in multiple subunits unique to plants, suggesting a plant-specific functional evolution of SWI/SNF complexes. We further demonstrate overlapping and specific genomic targeting of the three plant SWI/SNF complexes on chromatin and reveal that SAS complexes are necessary for the correct genomic localization of the BAS complexes. Finally, by focusing on the SAS and BAS complexes, we establish a requirement for both the core module subunit and the ATPase in the assembly of the plant SWI/SNF complexes. Together, our work highlights the divergence of SWI/SNF chromatin remodelers during the eukaryote evolution and provides a comprehensive landscape for understanding the plant SWI/SNF complexes organization, assembly, genomic targeting, and function.
2023-04-24 | GSE218841 | GEO
Project description:A systems understanding of nuclear organization and events is critical for determining how cells divide, differentiate and respond to stimuli and for identifying the causes of diseases. Chromatin remodeling complexes such as SWI/SNF have been implicated in a wide variety of cellular processes including gene expression, nuclear organization, centromere function and chromosomal stability, and mutations in SWI/SNF components have been linked to several types of cancer. To better understand the biological processes in which chromatin remodeling proteins participate we globally mapped binding regions for several components of the SWI/SNF complex throughout the human genome using ChIP-Seq. SWI/SNF components were found to lie near regulatory elements integral to transcription (e.g. 5M-bM-^@M-^Y ends, RNA Polymerases II and III and enhancers) as well as regions critical for chromosome organization (e.g. CTCF, lamins and DNA replication origins). To further elucidate the association of SWI/SNF subunits with each other as well as with other nuclear proteins we also analyzed SWI/SNF immunoprecipitated complexes by mass spectrometry. Individual SWI/SNF factors are associated with their own family members as well as with cellular constituents such as nuclear matrix proteins, key transcription factors and centromere components implying a ubiquitous role in gene regulation and nuclear function. We find an overrepresentation of both SWI/SNF-associated regions and proteins in cell cycle and chromosome organization. Taken together the results from our ChIP and immunoprecipitation experiments suggest that SWI/SNF facilitates gene regulation and genome function more broadly and through a greater diversity of interactions than previously appreciated. ChIP-Seq analysis of the SWI/SNF subunits Ini1, Brg1, BAF155 and BAF170 in HeLa S3 cells
2011-01-10 | E-GEOD-24397 | biostudies-arrayexpress
Project description:While oncogenes can potentially be inhibited with small molecules, the loss of tumor suppressors is more common and presents a conundrum for precision therapy because the proteins are no longer present. SMARCB1-mutant cancers epitomize this challenge because these highly lethal cancers are driven by inactivation of a single gene, a subunit of SWI/SNF chromatin remodeling complexes. To generate mechanistic insight into the consequences of SMARCB1 mutation and to seek vulnerabilities, we contributed 16 SMARCB1-mutant cell lines to a near-genomewide CRISPR screen as part of the Cancer Dependency Map1-3. Here we report that the little-studied gene DCAF5 (DDB1-CUL4 Associated Factor 5) is a specific dependency in SMARCB1-mutant cancers. We show that DCAF5 serves a quality control function for SWI/SNF complexes and in the absence of SMARCB1 DCAF5 causes degradation of incompletely assembled SWI/SNF complexes. Upon inhibition of DCAF5 SMARCB1-deficient SWI/SNF complexes re-accumulate, bind to target loci, and restore gene expression to levels sufficient to fully reverse the cancer state, including in a xenograft mouse model. Consequently, cancer results not from the loss of SMARCB1 function per se but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of DCAF5 may be sufficient to restore substantial SWI/SNF function and reverse cancer phenotypes caused by SMARCB1 loss.
2024-03-22 | GSE215023 | GEO
Project description:While oncogenes can potentially be inhibited with small molecules, the loss of tumor suppressors is more common and presents a conundrum for precision therapy because the proteins are no longer present. SMARCB1-mutant cancers epitomize this challenge because these highly lethal cancers are driven by inactivation of a single gene, a subunit of SWI/SNF chromatin remodeling complexes. To generate mechanistic insight into the consequences of SMARCB1 mutation and to seek vulnerabilities, we contributed 16 SMARCB1-mutant cell lines to a near-genomewide CRISPR screen as part of the Cancer Dependency Map1-3. Here we report that the little-studied gene DCAF5 (DDB1-CUL4 Associated Factor 5) is a specific dependency in SMARCB1-mutant cancers. We show that DCAF5 serves a quality control function for SWI/SNF complexes and in the absence of SMARCB1 DCAF5 causes degradation of incompletely assembled SWI/SNF complexes. Upon inhibition of DCAF5 SMARCB1-deficient SWI/SNF complexes re-accumulate, bind to target loci, and restore gene expression to levels sufficient to fully reverse the cancer state, including in a xenograft mouse model. Consequently, cancer results not from the loss of SMARCB1 function per se but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of DCAF5 may be sufficient to restore substantial SWI/SNF function and reverse cancer phenotypes caused by SMARCB1 loss.
2024-03-22 | GSE215022 | GEO
Project description:SWI/SNF chromatin remodeling complexes control gene expression by regulating chromatin structure. However, the full subunit composition of SWI/SNF complexes in plants remains unclear. Here we show that BRAHMA Interacting Protein 1 (BRIP1) and BRIP2 in Arabidopsis thaliana are core subunits of plant SWI/SNF complexes. BRIP1 and 2 are two homolog proteins. brip1 brip2 double mutants exhibit developmental phenotypes and a transcriptome strikingly similar to those of BRAHMA (BRM) mutants. Genetic interaction tests indicated that BRIP1 and 2 act together with BRM to regulate gene expression. Furthermore, BRIP1 and 2 physically interact with BRM-containing SWI/SNF complexes, and extensively co-localize with BRM at endogenous genes. Loss-of-brip1brip2 results in decreased BRM occupancy at almost all BRM target genes and substantially reduced subunits incorporation into the BRM-containing SWI/SNF complexes. Together, our work identifies new core subunits of BRM-containing SWI/SNF complexes in plants, and uncovers the essential role of these subunits in regulating the integrity (assembly) of SWI/SNF complexes in plants.
2020-06-21 | GSE142621 | GEO
Project description:While oncogenes can potentially be inhibited with small molecules, the loss of tumor suppressors is more common and is problematic because the tumor suppressor proteins are no longer present to be targeted. Notable examples include SMARCB1-mutant cancers, which are highly lethal malignancies driven by the inactivation of a subunit of SWI/SNF chromatin remodeling complexes. To generate mechanistic insight into the consequences of SMARCB1 mutation and to identify vulnerabilities, we contributed 14 SMARCB1-mutant cell lines to a near genome-wide CRISPR screen as part of the Cancer Dependency Map Project1-3. Here, we report that the little-studied gene DDB1-CUL4 Associated Factor 5 (DCAF5) is required for the survival of SMARCB1-mutant cancers. We show that DCAF5 serves a quality control function for SWI/SNF complexes and promotes degradation of incompletely assembled SWI/SNF complexes in the absence of SMARCB1. Upon depletion of DCAF5, SMARCB1-deficient SWI/SNF complexes re-accumulate, bind to target loci, and restore SWI/SNF-mediated gene expression to levels sufficient to reverse the cancer state, including in vivo. Consequently, cancer results not from the loss of SMARCB1 function per se but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of ubiquitin-mediated quality control factors may effectively reverse the malignant state of some cancers driven by disruption of tumor suppressor complexes.
2024-01-21 | PXD046275 | Pride
Project description:While oncogenes can potentially be inhibited with small molecules, the loss of tumor suppressors is more common and is problematic because the tumor suppressor proteins are no longer present to be targeted. Notable examples include SMARCB1-mutant cancers, which are highly lethal malignancies driven by the inactivation of a subunit of SWI/SNF chromatin remodeling complexes. To generate mechanistic insight into the consequences of SMARCB1 mutation and to identify vulnerabilities, we contributed 14 SMARCB1-mutant cell lines to a near genome-wide CRISPR screen as part of the Cancer Dependency Map Project1-3. Here, we report that the little-studied gene DDB1-CUL4 Associated Factor 5 (DCAF5) is required for the survival of SMARCB1-mutant cancers. We show that DCAF5 serves a quality control function for SWI/SNF complexes and promotes degradation of incompletely assembled SWI/SNF complexes in the absence of SMARCB1. Upon depletion of DCAF5, SMARCB1-deficient SWI/SNF complexes re-accumulate, bind to target loci, and restore SWI/SNF-mediated gene expression to levels sufficient to reverse the cancer state, including in vivo. Consequently, cancer results not from the loss of SMARCB1 function per se but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of ubiquitin-mediated quality control factors may effectively reverse the malignant state of some cancers driven by disruption of tumor suppressor complexes.
2024-01-21 | PXD046273 | Pride
Project description:While oncogenes can potentially be inhibited with small molecules, the loss of tumor suppressors is more common and is problematic because the tumor suppressor proteins are no longer present to be targeted. Notable examples include SMARCB1-mutant cancers, which are highly lethal malignancies driven by the inactivation of a subunit of SWI/SNF chromatin remodeling complexes. To generate mechanistic insight into the consequences of SMARCB1 mutation and to identify vulnerabilities, we contributed 14 SMARCB1-mutant cell lines to a near genome-wide CRISPR screen as part of the Cancer Dependency Map Project1-3. Here, we report that the little-studied gene DDB1-CUL4 Associated Factor 5 (DCAF5) is required for the survival of SMARCB1-mutant cancers. We show that DCAF5 serves a quality control function for SWI/SNF complexes and promotes degradation of incompletely assembled SWI/SNF complexes in the absence of SMARCB1. Upon depletion of DCAF5, SMARCB1-deficient SWI/SNF complexes re-accumulate, bind to target loci, and restore SWI/SNF-mediated gene expression to levels sufficient to reverse the cancer state, including in vivo. Consequently, cancer results not from the loss of SMARCB1 function per se but rather from DCAF5-mediated degradation of SWI/SNF complexes. These data indicate that therapeutic targeting of ubiquitin-mediated quality control factors may effectively reverse the malignant state of some cancers driven by disruption of tumor suppressor complexes.
2024-01-21 | PXD046276 | Pride
Project description:Bromodomain-containing protein 9 (BRD9) was recently identified to be associated with the chromatin remodeling SWI/SNF(BAF) complex, yet its function within the complex has remained unclear. Here, using genome-scale CRISPR-Cas9 screens, we found that BRD9 constitutes a specific vulnerability in highly malignant pediatric rhabdoid tumors, which are driven by inactivating mutations of SMARCB1 subunit of SWI/SNF complexes. Surprisingly, we found that BRD9 does not belong to the previously identified BAF or PBAF complexes, but instead is found exclusively in a novel of SWI/SNF sub-complex. We show that BRD9-containing complexes lack SMARCB1, which had previously been considered a core subunit present in all SWI/SNF variants. We recently demonstrated that both SMARCB1-containing and ARID1A-containing SWI/SNF complexes preferentially function at enhancers, but here we show that BRD9-containing complexes are located at active promoters as well as enhancers. We show that loss of SMARCB1, as observed in rhabdoid tumors, results in increased BRD9 interaction with SWI/SNF core subunit SMARCC1, consistent with competition between SMARCB1 and BRD9 in the formation of SWI/SNF complexes. Underlying the dependency, we demonstrate that BRD9, via its DUF3512 domain, is essential for maintaining the integrity of its sub-complex, which predominates in the absence of SMARCB1. Taken together, our results reveal a BRD9-containing SWI/SNF subcomplex which is required for the survival of SMARCB1-mutant rhabdoid tumors.
2019-03-14 | GSE120234 | GEO