Regulation of transcriptional interference by the Swi/Snf complex [ChIP-seq]
Ontology highlight
ABSTRACT: Alternative transcription start sites regulate transcript isoform diversity and, in turn, often regulate translation levels for a given gene. Recently, a form of gene regulation was described in which transcriptional and translational interference are coordinated, resulting in transcript isoform-dependent changes in protein expression for affected genes. In this form of gene regulation, a long undecoded transcript isoform (LUTI) is transcribed from a gene-distal promoter, interfering with expression of the gene-proximal promoter. While transcriptional and chromatin features associated with LUTI expression have been described, the mechanism underlying LUTI-based transcriptional interference is not well-understood. Using an unbiased genetic approach followed by integrated genomic analysis, we have found that the Swi/Snf chromatin remodeling complex is required for co-transcriptional nucleosome remodeling that leads to LUTI-mediated repression. We uncovered twelve genes with tandem promoters that rely on Swi/Snf function for transcriptional interference during protein folding stress, including three LUTI-regulated genes. Our results provide evidence that, in addition to its canonical function in gene activation, the Swi/Snf complex directly represses promoters that are subject to transcriptional readthrough.
Project description:Alternative transcription start sites regulate transcript isoform diversity and, in turn, often regulate translation levels for a given gene. Recently, a form of gene regulation was described in which transcriptional and translational interference are coordinated, resulting in transcript isoform-dependent changes in protein expression for affected genes. In this form of gene regulation, a long undecoded transcript isoform (LUTI) is transcribed from a gene-distal promoter, interfering with expression of the gene-proximal promoter. While transcriptional and chromatin features associated with LUTI expression have been described, the mechanism underlying LUTI-based transcriptional interference is not well-understood. Using an unbiased genetic approach followed by integrated genomic analysis, we have found that the Swi/Snf chromatin remodeling complex is required for co-transcriptional nucleosome remodeling that leads to LUTI-mediated repression. We uncovered twelve genes with tandem promoters that rely on Swi/Snf function for transcriptional interference during protein folding stress, including three LUTI-regulated genes. Our results provide evidence that, in addition to its canonical function in gene activation, the Swi/Snf complex directly represses promoters that are subject to transcriptional readthrough.
Project description:Alternative transcription start sites regulate transcript isoform diversity and, in turn, often regulate translation levels for a given gene. Recently, a form of gene regulation was described in which transcriptional and translational interference are coordinated, resulting in transcript isoform-dependent changes in protein expression for affected genes. In this form of gene regulation, a long undecoded transcript isoform (LUTI) is transcribed from a gene-distal promoter, interfering with expression of the gene-proximal promoter. While transcriptional and chromatin features associated with LUTI expression have been described, the mechanism underlying LUTI-based transcriptional interference is not well-understood. Using an unbiased genetic approach followed by integrated genomic analysis, we have found that the Swi/Snf chromatin remodeling complex is required for co-transcriptional nucleosome remodeling that leads to LUTI-mediated repression. We uncovered twelve genes with tandem promoters that rely on Swi/Snf function for transcriptional interference during protein folding stress, including three LUTI-regulated genes. Our results provide evidence that, in addition to its canonical function in gene activation, the Swi/Snf complex directly represses promoters that are subject to transcriptional readthrough.
Project description:Alternative transcription start sites regulate transcript isoform diversity and, in turn, often regulate translation levels for a given gene. Recently, a form of gene regulation was described in which transcriptional and translational interference are coordinated, resulting in transcript isoform-dependent changes in protein expression for affected genes. In this form of gene regulation, a long undecoded transcript isoform (LUTI) is transcribed from a gene-distal promoter, interfering with expression of the gene-proximal promoter. While transcriptional and chromatin features associated with LUTI expression have been described, the mechanism underlying LUTI-based transcriptional interference is not well-understood. Using an unbiased genetic approach followed by integrated genomic analysis, we have found that the Swi/Snf chromatin remodeling complex is required for co-transcriptional nucleosome remodeling that leads to LUTI-mediated repression. We uncovered twelve genes with tandem promoters that rely on Swi/Snf function for transcriptional interference during protein folding stress, including three LUTI-regulated genes. Our results provide evidence that, in addition to its canonical function in gene activation, the Swi/Snf complex directly represses promoters that are subject to transcriptional readthrough.
Project description:Alternative transcription start sites regulate transcript isoform diversity and, in turn, often regulate translation levels for a given gene. Recently, a form of gene regulation was described in which transcriptional and translational interference are coordinated, resulting in transcript isoform-dependent changes in protein expression for affected genes. In this form of gene regulation, a long undecoded transcript isoform (LUTI) is transcribed from a gene-distal promoter, interfering with expression of the gene-proximal promoter. While transcriptional and chromatin features associated with LUTI expression have been described, the mechanism underlying LUTI-based transcriptional interference is not well-understood. Using an unbiased genetic approach followed by integrated genomic analysis, we have found that the Swi/Snf chromatin remodeling complex is required for co-transcriptional nucleosome remodeling that leads to LUTI-mediated repression. We uncovered twelve genes with tandem promoters that rely on Swi/Snf function for transcriptional interference during protein folding stress, including three LUTI-regulated genes. Our results provide evidence that, in addition to its canonical function in gene activation, the Swi/Snf complex directly represses promoters that are subject to transcriptional readthrough.
Project description:Long Undecoded Transcript Isoforms (LUTIs) represent a class of non-canonical mRNAs that downregulate gene expression through the combined act of transcriptional and translational repression. While single gene studies revealed some important aspects of LUTI-based repression, how these features impact gene regulation at a global scale is unknown. By using transcript leader and direct RNA sequencing, here we identify 74 LUTI candidates that are expressed specifically during meiotic prophase. Translational repression of these candidates is ubiquitous and dependent on upstream open reading frames. However, LUTI-based transcriptional repression is highly variable. In only 50% of the cases, LUTI transcription causes downregulation of the protein-coding transcript isoform. Higher LUTI expression, enrichment of histone 3 lysine 36 trimethylation, and changes in nucleosome position are the strongest predictors of LUTI-based transcriptional repression. We conclude that LUTIs downregulate gene expression in a manner that integrates translational repression, chromatin state changes, and the magnitude of LUTI expression.
Project description:Precision genome-editing approaches have long been available in budding yeast, enabling introduction of gene deletions, epitope tag fusions, and promoter swaps through a selection-based strategy. Such approaches allow loci to be modified without disruption of coding or regulatory sequences of neighboring genes. Use of this approach to delete DBP1 however, led to silencing of expression and the resultant loss of function for the neighboring gene MRP51. We found that insertion of a resistance cassette to delete DBP1, drove a 5' extended alternative transcript for MRP51 which dampened Mrp51 protein synthesis. Misregulation of MRP51 occurred through an integrated transcriptional and translational repressive long undecoded transcript isoform (LUTI)-based mechanism that was recently shown to naturally regulate gene expression in yeast and other organisms. Cassette-induced MRP51 repression drove all mutant phenotypes we detected in cells deleted for DBP1. Selection cassette-mediated aberrant transcription events are not specific to this locus or a unique cassette but can be prevented by insertion of transcription insulators flanking the cassette. Our study suggests the existence of confounding off-target mutant phenotypes resulting from misregulated neighboring loci following genome edits in yeast. Furthermore, features of LUTI-based regulation are broadly conserved to eukaryotic organisms which indicates the potential that similar misregulation could be unnoticed in other edited organisms as well.
Project description:Cyclin Dependent Kinases CDK8 and CDK19 (Mediator kinase) are regulatory components of the Mediator complex, a highly conserved complex that fine tunes transcriptional output. While Mediator kinase has been implicated in the transcriptional control of key pathways necessary for development and growth, its function in vivo has not been well described. Herein, we report the consequences of complete ablation of both Cdk8/19 on tissue homeostasis. We show that intestinal epithelial specific deletion of Mediator kinase leads to a distinct defect in secretory progenitor differentiation with broad loss of the intestinal secretory cell types. Using a phospho-proteogenomic approach, we show that the Cdk8/19 kinase module interacts with and phosphorylates components of the chromatin remodeling complex Swi/Snf in intestinal epithelial cells. Genomic localisation of Swi/Snf and Mediator shows Cdk8/19-dependent genomic binding at distinct super-enhancer loci within key lineage specification genes, including the master regulator of secretory differentiation ATOH1. Using CRISPRi/CRISPRa, we identify a distinct Mediator-Swi/Snf bound enhancer element that is necessary and sufficient for ATOH1 expression in a Mediator-kinase dependent manner. As such, these studies uncover a newly described transcriptional mechanism of ATOH1-dependent intestinal cell specification that is dependent on the coordinated interaction of the chromatin remodeling complex Swi/Snf and Mediator complex.
Project description:Cyclin Dependent Kinases CDK8 and CDK19 (Mediator kinase) are regulatory components of the Mediator complex, a highly conserved complex that fine tunes transcriptional output. While Mediator kinase has been implicated in the transcriptional control of key pathways necessary for development and growth, its function in vivo has not been well described. Herein, we report the consequences of complete ablation of both Cdk8/19 on tissue homeostasis. We show that intestinal epithelial specific deletion of Mediator kinase leads to a distinct defect in secretory progenitor differentiation with broad loss of the intestinal secretory cell types. Using a phospho-proteogenomic approach, we show that the Cdk8/19 kinase module interacts with and phosphorylates components of the chromatin remodeling complex Swi/Snf in intestinal epithelial cells. Genomic localisation of Swi/Snf and Mediator shows Cdk8/19-dependent genomic binding at distinct super-enhancer loci within key lineage specification genes, including the master regulator of secretory differentiation ATOH1. Using CRISPRi/CRISPRa, we identify a distinct Mediator- Swi/Snf bound enhancer element that is necessary and sufficient for ATOH1 expression in a Mediator-kinase dependent manner. As such, these studies uncover a newly described transcriptional mechanism of ATOH1-dependent intestinal cell specification that is dependent on the coordinated interaction of the chromatin remodeling complex Swi/Snf and Mediator complex.