BAF60/SWP73 Subunits Define Subclasses of SWI/SNF Chromatin Remodelling Complexes in Arabidopsis
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE261097 | GEO | 2025/04/10
REPOSITORIES: GEO
Similar Datasets
Project description:• Evolutionarily conserved SWI-SNF ATP-dependent chromatin remodeling complexes (CRCs) change nucleosome positioning and chromatin states, affecting gene expression to regulate important regulatory processes controlling such as proper development and hormonal signalling pathways. • In our study we used transcript profiling, chromatin immunoprecipitation (ChIP), exhaustive protein-protein interaction study including mass-spectrometry, yeast-two-hybrid and bimolecular fluorescence complementation (BiFC) along with hormone and metabolite profiling, and phenotype assessments to distinguish the functions of Arabidopsis SWP73A and SWP73B subunits in Arabidopsis. • We identified a novel subclass of SWI/SNF chromatin remodelling complexes defined by the presence of SWP73A subunit. Therefore, we propose a refined classification of SWI/SNF CRCs in Arabidopsis, introducing BAS-A (SWP73A-containing) and BAS-B (SWP73B-containing) subclasses. The SWP73A and SWP73B-carrying subclasses of SWI/SNF CRCs exhibit differential properties demonstrated by distinct chromatin binding patterns and divergent effect on hormone biosynthesis and metabolism. We found that SWP73A plays a specific role that cannot be fully compensated by SWP73B. We recognized that some atypical subclasses of SWI/SNF CRCs may be likely formed in mutant lines with inactivated SWP73 subunits. • Our study reveals that the duplication of the SWP73 subunit contributes to unique and shared functions of subclasses of SWI/SNF CRCs in the control of various regulatory processes in Arabidopsis.
2025-04-15 | PXD056187 | Pride
Project description:The SWI/SNF (or BAF) complex is an essential chromatin remodeler that regulates DNA accessibility at developmental genes and enhancers. SWI/SNF subunits are among the most frequently mutated genes in cancer and neurodevelopmental disorders. These mutations are often heterozygous loss-of-function alleles, indicating a dosage-sensitive role for SWI/SNF subunits in chromatin regulation. However, the molecular mechanisms that regulate SWI/SNF subunit dosage to ensure proper complex assembly remain largely unexplored. We performed a genome-wide CRISPR KO screen, using epigenome editing in mouse embryonic stem cells, and identified Mlf2 and Rbm15 as regulators of SWI/SNF complex activity. First, we show that MLF2, a poorly characterized chaperone protein, regulates a subset of SWI/SNF target genes by promoting its chromatin remodeling activity. Rapid degradation of MLF2 reduces chromatin accessibility at sites that depend on high levels of SWI/SNF binding to maintain open chromatin. Next, we find that RBM15, part of the m6A RNA methylation writer complex, controls m6A modifications on specific SWI/SNF mRNAs to regulate protein levels of these subunits. Misregulation of m6A methylation causes overexpression of core SWI/SNF subunits leading to the assembly of incomplete complexes lacking the catalytic ATPase/ARP subunits. These data indicate that targeting modulators of SWI/SNF complex assembly may offer a potent therapeutic strategy for diseases associated with impaired chromatin remodeling.
2025-04-28 | PXD054392 | Pride
Project description:The SWI/SNF (or BAF) complex is an essential chromatin remodeler that regulates DNA accessibility at developmental genes and enhancers. SWI/SNF subunits are among the most frequently mutated genes in cancer and neurodevelopmental disorders. These mutations are often heterozygous loss-of-function alleles, indicating a dosage-sensitive role for SWI/SNF subunits in chromatin regulation. However, the molecular mechanisms that regulate SWI/SNF subunit dosage to ensure proper complex assembly remain largely unexplored. We performed a genome-wide CRISPR KO screen, using epigenome editing in mouse embryonic stem cells, and identified Mlf2 and Rbm15 as regulators of SWI/SNF complex activity. First, we show that MLF2, a poorly characterized chaperone protein, regulates a subset of SWI/SNF target genes by promoting its chromatin remodeling activity. Rapid degradation of MLF2 reduces chromatin accessibility at sites that depend on high levels of SWI/SNF binding to maintain open chromatin. Next, we find that RBM15, part of the m6A RNA methylation writer complex, controls m6A modifications on specific SWI/SNF mRNAs to regulate protein levels of these subunits. Misregulation of m6A methylation causes overexpression of core SWI/SNF subunits leading to the assembly of incomplete complexes lacking the catalytic ATPase/ARP subunits. These data indicate that targeting modulators of SWI/SNF complex assembly may offer a potent therapeutic strategy for diseases associated with impaired chromatin remodeling.
2025-04-28 | PXD061408 | Pride
Project description:The SWI/SNF (or BAF) complex is an essential chromatin remodeler that regulates DNA accessibility at developmental genes and enhancers. SWI/SNF subunits are among the most frequently mutated genes in cancer and neurodevelopmental disorders. These mutations are often heterozygous loss-of-function alleles, indicating a dosage-sensitive role for SWI/SNF subunits in chromatin regulation. However, the molecular mechanisms that regulate SWI/SNF subunit dosage to ensure proper complex assembly remain largely unexplored. We performed a genome-wide CRISPR KO screen, using epigenome editing in mouse embryonic stem cells, and identified Mlf2 and Rbm15 as regulators of SWI/SNF complex activity. First, we show that MLF2, a poorly characterized chaperone protein, regulates a subset of SWI/SNF target genes by promoting chromatin remodeling activity. Next, we find that RBM15, part of the m6A RNA methylation writer complex, controls m6A modifications on specific SWI/SNF mRNAs to regulate protein levels of these subunits. Misregulation of m6A methylation causes overexpression of core SWI/SNF subunits leading to the assembly of incomplete complexes lacking the catalytic ATPase/ARP subunits. These data indicate that targeting modulators of SWI/SNF complex assembly may offer a potent therapeutic strategy for diseases associated with impaired chromatin remodeling.
2025-04-28 | GSE268206 | GEO
Project description:The 12-subunit Swi/Snf chromatin remodeling complex is conserved from yeast to humans. It functions to alter nucleosome positions by either sliding nucleosomes on DNA or evicting histones. Interestingly, 20% of all human cancers carry mutations in subunits of the Swi/Snf complex. Many of these mutations cause protein instability and loss, resulting in partial Swi/Snf complexes. Although several studies have shown that histone acetylation and activator-dependent recruitment of Swi/Snf regulate its function, it is less well understood how subunits regulate stability and function of the complex. Using functional proteomic and genomic approaches, we have assembled the network architecture of yeast Swi/Snf. In addition, we find that subunits of the Swi/Snf complex regulate occupancy of the catalytic subunit Snf2, thereby modulating gene transcription. Our findings have direct bearing on how cancer-causing mutations in orthologous subunits of human Swi/Snf may lead to aberrant regulation of gene expression by this complex.
2017-08-07 | MSV000081418 | MassIVE
Project description:The 12-subunit Swi/Snf chromatin remodeling complex is conserved from yeast to humans. It functions to alter nucleosome positions by either sliding nucleosomes on DNA or evicting histones. Interestingly, 20% of all human cancers carry mutations in subunits of the Swi/Snf complex. Many of these mutations cause protein instability and loss, resulting in partial Swi/Snf complexes. Although several studies have shown that histone acetylation and activator-dependent recruitment of Swi/Snf regulate its function, it is less well understood how subunits regulate stability and function of the complex. Using functional proteomic and genomic approaches, we have assembled the network architecture of yeast Swi/Snf. In addition, we find that subunits of the Swi/Snf complex regulate occupancy of the catalytic subunit Snf2, thereby modulating gene transcription. Our findings have direct bearing on how cancer-causing mutations in orthologous subunits of human Swi/Snf may lead to aberrant regulation of gene expression by this complex.
2017-08-07 | MSV000081417 | MassIVE
Project description:In this study, DCAF5, a substrate receptor that has been shown to modulate the levels of SWI/SNF subunits, which are components of a chromatin remodeling complex. Here we preformed ubiquitinome proteomics to discover the underlying response of DCAF5 loss on ubiquitylation of SWI/SNF subunits. Furthermore, we determine what sites on SWI/SNF components decrease in ubiquitylation upon DCAF5 loss.
2024-03-25 | PXD046463 | Pride
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: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:The SWI/SNF chromatin remodeling complex is altered in ~20% of human cancers. ARID1A, a component of the SWI/SNF chromatin-remodeling complex, is the most frequently mutated epigenetic regulator in human cancers. Inactivation of the SWI/SNF complex is synthetically lethal with inhibition of EZH2 activity. EZH2 inhibitors are entering clinical trials for specific tumor types with SWI/SNF mutations. However, mechanisms of de novo or acquired resistance to EZH2 inhibitors in cancers with inactivating SWI/SNF mutations are unknown. Here we show that the switch of the SWI/SNF catalytic subunits from SMARCA4 to SMARCA2 drives resistance to EZH2 inhibitors in ARID1A-mutated ovarian cancer cells.
2019-02-10 | GSE110449 | GEO