Project description:RNA-mediated transcriptional silencing prevents deleterious effects of transposon activity and controls the expression of protein-coding genes. It involves long non-coding RNAs (lncRNAs)1, which in Arabidopsis thaliana are produced by a specialized RNA Polymerase V (Pol V)2. lncRNAs guide Argonaute-siRNA complexes to specific genomic loci and mediate the establishment of DNA methylation3,4. The mechanism by which lncRNAs affect chromatin structure and mRNA production remains mostly unknown. Here we identify the SWI/SNF nucleosome remodeling complex as a component of the RNA-mediated transcriptional silencing pathway. We found that SWI3, an essential subunit of the SWI/SNF complex, physically interacts with a lncRNA-binding IDN2 protein5,6. RNA-mediated DNA methylation and transcriptional silencing was compromised in the swi3 mutant. Moreover, targets of SWI/SNF significantly overlapped with genes controlled by Pol V, which shows that the physical interaction reflects a functional relationship. We further found that non-coding transcription by Pol V affects nucleosome positioning on silenced regions. We propose that lncRNAs mediate transcriptional silencing by guiding the SWI/SNF complex and establishing positioned nucleosomes on specific genomic loci. We further propose that guiding ATP-dependent chromatin remodeling complexes may be a more general function of lncRNAs. H3 ChIP-seq of 2 samples (Col-0 and nrpe1) with 2 biological repeats.
Project description:RNA-mediated transcriptional silencing prevents deleterious effects of transposon activity and controls the expression of protein-coding genes. It involves long non-coding RNAs (lncRNAs)1, which in Arabidopsis thaliana are produced by a specialized RNA Polymerase V (Pol V)2. lncRNAs guide Argonaute-siRNA complexes to specific genomic loci and mediate the establishment of DNA methylation3,4. The mechanism by which lncRNAs affect chromatin structure and mRNA production remains mostly unknown. Here we identify the SWI/SNF nucleosome remodeling complex as a component of the RNA-mediated transcriptional silencing pathway. We found that SWI3, an essential subunit of the SWI/SNF complex, physically interacts with a lncRNA-binding IDN2 protein5,6. RNA-mediated DNA methylation and transcriptional silencing was compromised in the swi3 mutant. Moreover, targets of SWI/SNF significantly overlapped with genes controlled by Pol V, which shows that the physical interaction reflects a functional relationship. We further found that non-coding transcription by Pol V affects nucleosome positioning on silenced regions. We propose that lncRNAs mediate transcriptional silencing by guiding the SWI/SNF complex and establishing positioned nucleosomes on specific genomic loci. We further propose that guiding ATP-dependent chromatin remodeling complexes may be a more general function of lncRNAs. Mnase-seq of 2 samples (Col-0 and nrpe1).
Project description:RNA-mediated transcriptional silencing prevents deleterious effects of transposon activity and controls the expression of protein-coding genes. It involves long non-coding RNAs (lncRNAs)1, which in Arabidopsis thaliana are produced by a specialized RNA Polymerase V (Pol V)2. lncRNAs guide Argonaute-siRNA complexes to specific genomic loci and mediate the establishment of DNA methylation3,4. The mechanism by which lncRNAs affect chromatin structure and mRNA production remains mostly unknown. Here we identify the SWI/SNF nucleosome remodeling complex as a component of the RNA-mediated transcriptional silencing pathway. We found that SWI3, an essential subunit of the SWI/SNF complex, physically interacts with a lncRNA-binding IDN2 protein5,6. RNA-mediated DNA methylation and transcriptional silencing was compromised in the swi3 mutant. Moreover, targets of SWI/SNF significantly overlapped with genes controlled by Pol V, which shows that the physical interaction reflects a functional relationship. We further found that non-coding transcription by Pol V affects nucleosome positioning on silenced regions. We propose that lncRNAs mediate transcriptional silencing by guiding the SWI/SNF complex and establishing positioned nucleosomes on specific genomic loci. We further propose that guiding ATP-dependent chromatin remodeling complexes may be a more general function of lncRNAs. RNA-seq of 3 samples (Col-0, nrpe1 [a mutant defective in the largest subunit of Pol V and unable to produce lncRNA], swi3b, idn2) with 3 biological replicates.
Project description:RNA-mediated transcriptional silencing prevents deleterious effects of transposon activity and controls the expression of protein-coding genes. It involves long non-coding RNAs (lncRNAs)1, which in Arabidopsis thaliana are produced by a specialized RNA Polymerase V (Pol V)2. lncRNAs guide Argonaute-siRNA complexes to specific genomic loci and mediate the establishment of DNA methylation3,4. The mechanism by which lncRNAs affect chromatin structure and mRNA production remains mostly unknown. Here we identify the SWI/SNF nucleosome remodeling complex as a component of the RNA-mediated transcriptional silencing pathway. We found that SWI3, an essential subunit of the SWI/SNF complex, physically interacts with a lncRNA-binding IDN2 protein5,6. RNA-mediated DNA methylation and transcriptional silencing was compromised in the swi3 mutant. Moreover, targets of SWI/SNF significantly overlapped with genes controlled by Pol V, which shows that the physical interaction reflects a functional relationship. We further found that non-coding transcription by Pol V affects nucleosome positioning on silenced regions. We propose that lncRNAs mediate transcriptional silencing by guiding the SWI/SNF complex and establishing positioned nucleosomes on specific genomic loci. We further propose that guiding ATP-dependent chromatin remodeling complexes may be a more general function of lncRNAs.
Project description:RNA-mediated transcriptional silencing prevents deleterious effects of transposon activity and controls the expression of protein-coding genes. It involves long non-coding RNAs (lncRNAs)1, which in Arabidopsis thaliana are produced by a specialized RNA Polymerase V (Pol V)2. lncRNAs guide Argonaute-siRNA complexes to specific genomic loci and mediate the establishment of DNA methylation3,4. The mechanism by which lncRNAs affect chromatin structure and mRNA production remains mostly unknown. Here we identify the SWI/SNF nucleosome remodeling complex as a component of the RNA-mediated transcriptional silencing pathway. We found that SWI3, an essential subunit of the SWI/SNF complex, physically interacts with a lncRNA-binding IDN2 protein5,6. RNA-mediated DNA methylation and transcriptional silencing was compromised in the swi3 mutant. Moreover, targets of SWI/SNF significantly overlapped with genes controlled by Pol V, which shows that the physical interaction reflects a functional relationship. We further found that non-coding transcription by Pol V affects nucleosome positioning on silenced regions. We propose that lncRNAs mediate transcriptional silencing by guiding the SWI/SNF complex and establishing positioned nucleosomes on specific genomic loci. We further propose that guiding ATP-dependent chromatin remodeling complexes may be a more general function of lncRNAs.
Project description:RNA-mediated transcriptional silencing prevents deleterious effects of transposon activity and controls the expression of protein-coding genes. It involves long non-coding RNAs (lncRNAs)1, which in Arabidopsis thaliana are produced by a specialized RNA Polymerase V (Pol V)2. lncRNAs guide Argonaute-siRNA complexes to specific genomic loci and mediate the establishment of DNA methylation3,4. The mechanism by which lncRNAs affect chromatin structure and mRNA production remains mostly unknown. Here we identify the SWI/SNF nucleosome remodeling complex as a component of the RNA-mediated transcriptional silencing pathway. We found that SWI3, an essential subunit of the SWI/SNF complex, physically interacts with a lncRNA-binding IDN2 protein5,6. RNA-mediated DNA methylation and transcriptional silencing was compromised in the swi3 mutant. Moreover, targets of SWI/SNF significantly overlapped with genes controlled by Pol V, which shows that the physical interaction reflects a functional relationship. We further found that non-coding transcription by Pol V affects nucleosome positioning on silenced regions. We propose that lncRNAs mediate transcriptional silencing by guiding the SWI/SNF complex and establishing positioned nucleosomes on specific genomic loci. We further propose that guiding ATP-dependent chromatin remodeling complexes may be a more general function of lncRNAs.
Project description:Aberrant forms of the SWI/SNF chromatin remodeling complex are associated with human disease. Loss of the Snf5 subunit of SWI/SNF is a driver mutation in pediatric rhabdoid cancers and forms aberrant sub-complexes that are not well characterized. We determined the effects of loss of Snf5 on the composition, nucleosome binding, recruitment and remodeling activities of yeast SWI/SNF. The Snf5 subunit interacts with the ATPase domain of Snf2 and forms a submodule consisting of Snf5, Swp82 and Taf14 as shown by mapping SWI/SNF subunit interactions by crosslinking-mass spectrometry and subunit deletion followed by immunoaffinity chromatography. Snf5 promoted binding of the Snf2 ATPase domain to nucleosomal DNA, enhanced its catalytic activity and facilitated nucleosome remodeling. Snf5 was required for acidic transcription factors to recruit SWI/SNF to chromatin. RNA-seq analysis suggested that both the recruitment and catalytic functions mediated by Snf5 are required for SWI/SNF regulation of gene expression.