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PROVIDER: PRJNA135901 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Clr4/Suv39 and RNA quality control factors cooperate to trigger RNAi and suppress antisense RNA (expression)
| PRJNA142035 | ENA
Project description:Clr4/Suv39 and RNA quality control factors cooperate to trigger RNAi and suppress antisense RNA (ChIP)
| PRJNA142037 | ENA
Project description:In eukaryotes, the Suv39 family of proteins tri-methylate lysine 9 of histone H3 (H3K9me) to form constitutive heterochromatin. However, how Suv39 proteins are nucleated at heterochromatin is not fully described. In the fission yeast, current models posit that Argonaute1-associated small RNAs (sRNAs) nucleate the sole H3K9 methyltransferase, Clr4/SUV39H, to centromeres. Here, we show that in the absence of all sRNAs and H3K9me, the Mtl1 and Red1 core (MTREC)/PAXT complex nucleates Clr4/SUV39H at a heterochromatic long noncoding RNA (lncRNA) at which the two H3K9 deacetylases, Sir2 and Clr3, also accumulate by distinct mechanisms. Iterative cycles of H3K9 deacetylation and methylation spread Clr4/SUV39H from the nucleation center in an sRNA-independent manner, generating a basal H3K9me state. This is acted upon by the RNAi machinery to augment and amplify the Clr4/H3K9me signal at centromeres to establish heterochromatin. Overall, our data reveal that lncRNAs and RNA quality control factors can nucleate heterochromatin and function as epigenetic silencers in eukaryotes.
2024-05-16 | PXD039519 | Pride
Project description:Histone H2A.Z cooperates with RNAi and heterochromatin factors to suppress antisense RNAs
| PRJNA119129 | ENA
Project description:Co-transcriptional RNA processing and surveillance factors mediate heterochromatin formation in fission yeast. In addition to RNAi, RNA elimination machinery including MTREC (Mtl1-Red1 core) and the exosome are involved in facultative heterochromatin assembly, however, the exact mechanisms remain unclear. Here we show that RNA elimination factors cooperate with the conserved exoribonuclease Dhp1/Rat1/Xrn2, which couples pre-mRNA 3â-end processing to transcription termination, to promote premature termination and facultative heterochromatin formation at meiotic genes. Dhp1 also affects termination of transcripts at genes that are targets of RNAi-mediated heterochromatin assembly. Moreover, Dhp1 facilitates constitutive heterochromatin formation and silencing at centromeric and mating-type loci. Remarkably, we find that Dhp1 interacts with the Clr4/Suv39h methyltransferase complex and acts directly to nucleate heterochromatin. Our results uncover a novel role for 3â-end processing and termination machinery in gene silencing through premature termination and suggest that non-canonical termination by Dhp1 and RNA elimination factors is linked to heterochromatin assembly. These findings have important implications for understanding mechanisms of gene silencing in higher eukaryotes. Sequencing and analysis of small RNA in two S. pombe mutants
2016-01-05 | E-GEOD-74739 | biostudies-arrayexpress
Project description:Co-transcriptional RNA processing and surveillance factors mediate heterochromatin formation in fission yeast. In addition to RNAi, RNA elimination machinery including MTREC (Mtl1-Red1 core) and the exosome are involved in facultative heterochromatin assembly, however, the exact mechanisms remain unclear. Here we show that RNA elimination factors cooperate with the conserved exoribonuclease Dhp1/Rat1/Xrn2, which couples pre-mRNA 3’-end processing to transcription termination, to promote premature termination and facultative heterochromatin formation at meiotic genes. Dhp1 also affects termination of transcripts at genes that are targets of RNAi-mediated heterochromatin assembly. Moreover, Dhp1 facilitates constitutive heterochromatin formation and silencing at centromeric and mating-type loci. Remarkably, we find that Dhp1 interacts with the Clr4/Suv39h methyltransferase complex and acts directly to nucleate heterochromatin. Our results uncover a novel role for 3’-end processing and termination machinery in gene silencing through premature termination and suggest that non-canonical termination by Dhp1 and RNA elimination factors is linked to heterochromatin assembly. These findings have important implications for understanding mechanisms of gene silencing in higher eukaryotes.
2016-01-05 | GSE74739 | GEO
Project description:Defects in RNA maturation and RNA decay factors may generate substrates for the RNA interference machinery. This phenomenon was observed in plants where mutations in some RNA-related factors lead to the production of RNA-quality control small interfering RNAs and several mutants show enhanced silencing of reporter transgenes. To assess the potential of RNAi activation on endogenous transcripts, we sequenced small RNAs from a set of Arabidopsis thaliana mutants with defects in various RNA metabolism pathways. We observed a global production of siRNAs caused by inefficient pre-mRNA cleavage and polyadenylation leading to read-through transcription into downstream antisense genes. In addition, in the lsm1a lsm1b double mutant, we identified NIA1, SMXL5, and several miRNA-targeted mRNAs as producing siRNAs, a group of transcripts suggested being especially sensitive to deficiencies in RNA metabolism. However, in most cases, RNA metabolism perturbations do not lead to the widespread production of siRNA derived from mRNA molecules. This observation is contrary to multiple studies based on reporter transgenes and suggests that only a very high accumulation of defective mRNA species caused by specific mutations or substantial RNA processing defects trigger RNAi pathways.
2022-02-02 | GSE169171 | GEO
Project description:In the fission yeast Schizosaccharomyces pombe, the RNA interference (RNAi) pathway is required to generate small interfering RNAs (siRNAs) that mediate heterochromatic silencing of centromeric repeats. Here we demonstrate that RNAi also functions to repress genomic elements other than constitutive heterochromatin. Using DamID (DNA adenine methyltransferase identification) we show that Dcr1 and Rdp1 physically associate with some euchromatic genes, non-coding RNA (ncRNA) genes, and retrotransposon long terminal repeats (LTRs), and that this association is independent of the Clr4 histone methyltransferase. Physical association of RNAi with chromatin is sufficient to trigger a silencing response but not to assemble heterochromatin. The mode of silencing at the newly identified RNAi targets is consistent with a co-transcriptional gene silencing model as proposed earlier and functions with trace amounts of siRNAs. We anticipate that similar mechanisms could also be operational in other eukaryotes.
2010-09-25 | GSE24360 | GEO
Project description:RNA surveillance (MTREC) and degradation (exosome) complexes nucleate Clr4/SUV39H at a heterochromatic long noncoding RNA, at which the two deacetylases, Sir2 and Clr3, also amass by distinct mechanisms. Iterative cycles of H3K9 deacetylation and methylation spread Clr4 from the nucleation center which with the help from RNAi establish heterochromatin. (this is like the abstract for the paper) To identify nuclear Sir2-interacting proteins, a protocol was adopted by which frozen intact nuclei suitable for biochemical purifications were released by low pressure, semi-automated cryogrinding of frozen yeast pellets after which the nuclei were isolated by differential centrifugation. From these nuclear extracts, FLAG-tagged Sir2 was purified and analyzed by nanoscale micro-capillary tandem mass spectrometry.
2024-02-25 | MSV000094160 | MassIVE