ABSTRACT: PKA-dependent Phosphorylation of A Histone Demethylase Drives Higher Order Chromatin Structures by Association with SWI/SNF Chromatin Remodeler
Project description:The current studies show that JMJD1A is phosphorylated at S265 by protein kinase A (PKA), and this is pivotal to activate expression of the b1-adrenergic receptor gene (Adrb1) and downstream targets including Ucp1. Phosphorylation of JMJD1A increases its interaction with the SWI/SNF nucleosome remodeling complex and DNA-bound PPARg. This complex conferred b-adrenergic-induced JMJD1A recruitment to target sites throughout the genome. Phospho-JMJD1A also facilitated long-range chromatin looping to recruit PPARg-bound distal-enhancers, SWI/SNF, and RNA polymerase close to the Adrb1 locus to activate transcription. Mutation of the PKA-phosphorylation site on JMJD1A abolished interactions with SWI/SNF without affecting demethylase activity suggesting the two functions are independent of each other. Our results show that JMJD1A demethylase is also a signal-sensing scaffold that regulates cAMP-responsive transcription via interactions with SWI/SNF and hormone stimulated higher-order chromatin conformational changes. There are 3 samples analyzed. No duplication from each sample. Isoproterenol stimulation at 0hr is used as the relative to fold change in manuscript.
Project description:The current studies show that JMJD1A is phosphorylated at S265 by protein kinase A (PKA), and this is pivotal to activate expression of the b1-adrenergic receptor gene (Adrb1) and downstream targets including Ucp1. Phosphorylation of JMJD1A increases its interaction with the SWI/SNF nucleosome remodeling complex and DNA-bound PPARg. This complex conferred b-adrenergic-induced JMJD1A recruitment to target sites throughout the genome. Phospho-JMJD1A also facilitated long-range chromatin looping to recruit PPARg-bound distal-enhancers, SWI/SNF, and RNA polymerase close to the Adrb1 locus to activate transcription. Mutation of the PKA-phosphorylation site on JMJD1A abolished interactions with SWI/SNF without affecting demethylase activity suggesting the two functions are independent of each other. Our results show that JMJD1A demethylase is also a signal-sensing scaffold that regulates cAMP-responsive transcription via interactions with SWI/SNF and hormone stimulated higher-order chromatin conformational changes.
Project description:The SWI/SNF ATP-dependent chromatin remodeler is a master regulator of the epigenome; controlling pluripotency, cell fate determination and differentiation. There is a sparsity of information on the autoregulation of SWI/SNF, the domains involved and their mode of action. We find a DNA or RNA binding module conserved from yeast to humans located in the C-terminus of the catalytic subunit of SWI/SNF called the AT-hook that positively regulates the chromatin remodeling activity of yeast and mouse SWI/SNF. The AT-hook in yeast SWI/SNF interacts with the SnAC and ATPase domains, which after binding to nucleosome switches to contacting the N-terminus of histone H3. Deletion of the AT-hooks in yeast SWI/SNF and mouse esBAF complexes reduces the remodeling activity of SWI/SNF without affecting complex integrity or its recruitment to nucleosomes. In addition, deletion of the AT-hook impairs the ATPase and nucleosome mobilizing activities of yeast SWI/SNF without disrupting the interactions of the ATPase domain with nucleosomal DNA. The AT-hook is also important in vivo for SWI/SNF-dependent response to amino acid starvation in yeast and for cell lineage priming in mouse embryonic stem cells. In summary, the AT-hook is shown to be an evolutionarily conserved autoregulatory domain of SWI/SNF that positively regulates SWI/SNF both in vitro and in vivo.
Project description:Tissue-specific transcription factors initiate differentiation toward a specialized cell type by inducing transcription-permissive chromatin modifications at target gene promoters, through the recruitment of the SWI/SNF chromatin-remodeling complex (1, 2). The molecular mechanism that regulates the chromatin re-distribution of SWI/SNF in response to differentiation signals is currently unknown. Here we show that the muscle determination factor MyoD and the SWI/SNF structural sub-unit, BAF60c (SMARCD3), form a complex on the regulatory elements of MyoD-target genes in undifferentiated myoblasts, prior to the activation of gene expression. MyoD-BAF60c complex is devoid of the ATP-dependent enzymatic sub-units Brg1 and Brm, is required for stable MyoD binding to Ebox sequences, and marks the chromatin for signal-dependent recruitment of the SWI/SNF core complex to muscle loci. BAF60c phosphorylation on a conserved threonine by differentiation-activated p38 signalling promotes the incorporation of MyoD-BAF60c into a Brg1-based SWI/SNF complex, which is competent to remodel the chromatin and activates transcription of MyoD-target genes. Our data support an unprecedented two-step model, by which pre-assembled BAF60c-MyoD complex directs the SWI/SNF complex chromatin re-distribution to muscle loci in response to differentiation cues. Differentiation of C2C12 cells individually interfered for BRG1, BAF60B, BAF60C
Project description:Using CRISPR-Cas9 to tag endogenous remodeler subunits in Drosophila melanogaster S2 cells, we demonstrate that developmental gene transcription requires SWI/SNF-type complexes, primarily to maintain distal enhancer accessibility.
Project description:In eukaryotes, ATP-dependent chromatin remodelers regulate gene expression in response to nutritional and metabolic stimuli. The Swi-Snf complex is one such remodeler that has been implicated in disease, where loss of Swi-Snf function leads to dysregulated gene transcription. However, altered transcription of metabolic genes may have consequences for entire pathways that remain poorly understood. In this study, we use genetic and molecular approaches to uncover a role for Swi-Snf as a critical regulator of metabolism. We find that Δsnf mutants are cysteine-deficient, despite growth in nutrient-rich media. This cysteine deficiency causes widespread perturbations in sulfur metabolic gene transcription. This includes global alteration and redistribution of the transcription factor Met4 which senses cysteine deficiency and also has roles in heavy metal stress response and cell cycle progression. Additionally, we show that in its role as a metabolic regulator, Swi-Snf is a critical determinant of survival following oxidative stress. Our findings show how a chromatin remodeler can have a significant impact on a whole metabolic pathway by directly regulating an important gene subset and demonstrate an emerging role for chromatin remodeling complexes as key determinants of metabolic control.
Project description:In eukaryotes, ATP-dependent chromatin remodelers regulate gene expression in response to nutritional and metabolic stimuli. The Swi-Snf complex is one such remodeler that has been implicated in disease, where loss of Swi-Snf function leads to dysregulated gene transcription. However, altered transcription of metabolic genes may have consequences for entire pathways that remain poorly understood. In this study, we use genetic and molecular approaches to uncover a role for Swi-Snf as a critical regulator of metabolism. We find that Δsnf mutants are cysteine-deficient, despite growth in nutrient-rich media. This cysteine deficiency causes widespread perturbations in sulfur metabolic gene transcription. This includes global alteration and redistribution of the transcription factor Met4 which senses cysteine deficiency and also has roles in heavy metal stress response and cell cycle progression. Additionally, we show that in its role as a metabolic regulator, Swi-Snf is a critical determinant of survival following oxidative stress. Our findings show how a chromatin remodeler can have a significant impact on a whole metabolic pathway by directly regulating an important gene subset and demonstrate an emerging role for chromatin remodeling complexes as key determinants of metabolic control.
Project description:In eukaryotes, ATP-dependent chromatin remodelers regulate gene expression in response to nutritional and metabolic stimuli. The Swi-Snf complex is one such remodeler that has been implicated in disease, where loss of Swi-Snf function leads to dysregulated gene transcription. However, altered transcription of metabolic genes may have consequences for entire pathways that remain poorly understood. In this study, we use genetic and molecular approaches to uncover a role for Swi-Snf as a critical regulator of metabolism. We find that Δsnf mutants are cysteine-deficient, despite growth in nutrient-rich media. This cysteine deficiency causes widespread perturbations in sulfur metabolic gene transcription. This includes global alteration and redistribution of the transcription factor Met4 which senses cysteine deficiency and also has roles in heavy metal stress response and cell cycle progression. Additionally, we show that in its role as a metabolic regulator, Swi-Snf is a critical determinant of survival following oxidative stress. Our findings show how a chromatin remodeler can have a significant impact on a whole metabolic pathway by directly regulating an important gene subset and demonstrate an emerging role for chromatin remodeling complexes as key determinants of metabolic control.
Project description:In eukaryotes, ATP-dependent chromatin remodelers regulate gene expression in response to nutritional and metabolic stimuli. The Swi-Snf complex is one such remodeler that has been implicated in disease, where loss of Swi-Snf function leads to dysregulated gene transcription. However, altered transcription of metabolic genes may have consequences for entire pathways that remain poorly understood. In this study, we use genetic and molecular approaches to uncover a role for Swi-Snf as a critical regulator of metabolism. We find that Δsnf mutants are cysteine-deficient, despite growth in nutrient-rich media. This cysteine deficiency causes widespread perturbations in sulfur metabolic gene transcription. This includes global alteration and redistribution of the transcription factor Met4 which senses cysteine deficiency and also has roles in heavy metal stress response and cell cycle progression. Additionally, we show that in its role as a metabolic regulator, Swi-Snf is a critical determinant of survival following oxidative stress. Our findings show how a chromatin remodeler can have a significant impact on a whole metabolic pathway by directly regulating an important gene subset and demonstrate an emerging role for chromatin remodeling complexes as key determinants of metabolic control.
Project description:PBRM1 is lost in 40% of clear cell renal cell carcinomas (ccRCC) and the combined loss of VHL and PBRM1 drives ccRCC tumorigenesis. PBRM1 is an accessory subunit of the PBAF subclass of the SWI/SNF chromatin remodeler and despite its well-established role as a tumor suppressor, we have limited understanding of how PBRM1 regulates the chromatin. Now we report that PBRM1 binds to promoter-proxy regions with footprints at +1 to + 3 nucleosomes. PBRM1-deficient PBAF complexes lose BRD7 but retain ARID2, while tethered to SMARCA4. The lack of PBRM1-BRD7 module compromises the targeting specificity of the PBAF complexes, causes their genomic redistribution and impairs the repressive ability of PBAF complexes. Subsequently, PBRM1-deficient PBAF complexes prime the chromatin at de novo sites for transcriptional activation of pro-survival genes involved in hypoxia and cholesterol synthesis. Therefore, PBRM1 safeguards the chromatin by repressing aberrant liberation of pro-survival genes by residual PBRM1-deficient SWI/SNF complexes.