Project description:The glucocorticoid-activated glucocorticoid receptor (GR) regulates cellular stress pathways by binding to genomic regulatory elements of target genes and recruiting coregulator proteins to remodel chromatin and regulate transcription complex assembly. The coregulator Hydrogen peroxide-inducible clone 5 (Hic-5) is required for glucocorticoid regulation of some genes, but not others, and blocks regulation of a third gene set. Hic-5 inhibits GR binding to blocked genes but not other glucocorticoid-regulated genes. Site-specific blocking of GR binding is due to gene-specific requirements for ATP-dependent chromatin remodeling enzymes. We investigate whether ATPases CHD9 and BRM were required for GR occupancy at GR binding sites near Hic-5 blocked genes.
Project description:The glucocorticoid-activated glucocorticoid receptor (GR) regulates cellular stress pathways by binding to genomic regulatory elements of target genes and recruiting coregulator proteins to remodel chromatin and regulate transcription complex assembly. The coregulator Hydrogen peroxide-inducible clone 5 (Hic-5) is required for glucocorticoid regulation of some genes, but not others, and blocks regulation of a third gene set. Hic-5 inhibits GR binding to blocked genes but not other glucocorticoid-regulated genes. Site-specific blocking of GR binding is due to gene-specific requirements for ATP-dependent chromatin remodeling enzymes. We investigate the effects of Hic-5 and dexamethasone on chromatin accessibility at GR binding sites near Hic-5 blocked genes and non-blocked genes.
Project description:ARGLU1 is a Transcriptional Coactivator and Splicing Regulator Important for Stress Hormone Signaling and Development Stress hormones bind and activate the glucocorticoid receptor (GR) in many tissues including the brain. We identified arginine and glutamate rich 1 (ARGLU1) in a screen for new modulators of glucocorticoid signaling in the CNS. Biochemical studies show that the glutamate rich C-terminus of ARGLU1 coactivates multiple nuclear receptors including the glucocorticoid receptor (GR) and the arginine rich N-terminus interacts with splicing factors and binds to RNA. RNA-seq of neuronal cells depleted of ARGLU1 revealed significant changes in the expression and alternative splicing of distinct genes involved in neurogenesis. Loss of ARGLU1 is embryonic lethal in mice, and knockdown in zebrafish causes neurodevelopmental and heart defects. Treatment with dexamethasone, a GR activator, also induces changes in the pattern of alternatively spliced genes, many of which were lost when ARGLU1 was absent. Importantly, the genes found to be alternatively spliced in response to glucocorticoid treatment were distinct from those under transcriptional control by GR, suggesting an additional mechanism of glucocorticoid action is present in neuronal cells. Our results thus show that ARGLU1 is a novel factor for embryonic development that modulates basal transcription and alternative splicing in neuronal cells with consequences for glucocorticoid signaling.
Project description:ARGLU1 is a Transcriptional Coactivator and Splicing Regulator Important for Stress Hormone Signaling and Development Stress hormones bind and activate the glucocorticoid receptor (GR) in many tissues including the brain. We identified arginine and glutamate rich 1 (ARGLU1) in a screen for new modulators of glucocorticoid signaling in the CNS. Biochemical studies show that the glutamate rich C-terminus of ARGLU1 coactivates multiple nuclear receptors including the glucocorticoid receptor (GR) and the arginine rich N-terminus interacts with splicing factors and binds to RNA. RNA-seq of neuronal cells depleted of ARGLU1 revealed significant changes in the expression and alternative splicing of distinct genes involved in neurogenesis. Loss of ARGLU1 is embryonic lethal in mice, and knockdown in zebrafish causes neurodevelopmental and heart defects. Treatment with dexamethasone, a GR activator, also induces changes in the pattern of alternatively spliced genes, many of which were lost when ARGLU1 was absent. Importantly, the genes found to be alternatively spliced in response to glucocorticoid treatment were distinct from those under transcriptional control by GR, suggesting an additional mechanism of glucocorticoid action is present in neuronal cells. Our results thus show that ARGLU1 is a novel factor for embryonic development that modulates basal transcription and alternative splicing in neuronal cells with consequences for glucocorticoid signaling.