Similar Datasets
Project description:Recruitment of Clr4 to heterochromatin
| PRJNA925208 | 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:To investigate the role of de novo methylation by Clr4, we performed the reintroduction of Clr4 and ecopic insertion of lnc230
2024-01-01 | GSE223203 | 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
Project description:Occupancy profiling of Mlo3 in wild type and clr4∆ fission yeast Schizosaccharomyces pombe Agilent 60mer array was used to analyze DNA recovered by immunoprecipitation of Mlo3-Flag from asynchronous culture of fission yeast.
2011-04-12 | E-GEOD-26997 | biostudies-arrayexpress
Project description:Expression profiling in clr4 null cells versus wild-type cells. Keywords: Expression
2005-08-31 | GSE3187 | GEO
Project description:A current model for the genomic recruitment of Kap1 is via its interaction with KRAB domain-containing zinc finger transcription factors. We have performed ChIP-seq for various mutant KAP1 proteins and shown that this recruitment mechanism mediates binding of KAP1 only to the 3M-CM-"M-BM-^@M-BM-^Y ends of zinc finger genes and that other factors are involved in recruiting KAP1 to promoter regions. 17 total ChIP-seq datasets; three different FLAG-KAP1 mutants, one FLAG-KAP1 wild type, and four different Input datasets from 4 different stable cell lines derived from HEK293 cells: 1 FLAG-KAP1 wild type dataset and 1 Input dataset done from HEK293 stable cells; 1 FLAG-KAP1 HP1BDmut dataset and 1 Input dataset done from HEK293 stable cells, 1 FLAG-KAP1 N-ter RBCC{delta}mut dataset and 1 Input dataset done from HEK293 stable cells, 1 FLAG-KAP1 C-ter PB{delta}mut dataset and 1 Input dataset done from HEK293 stable cells. One FLAG-KAP1 N/C-ter (RBCC+PB){delta}mut dataset done from T-REx HEK293 stable cells. One endogenous KAP1 dataset done from HEK293 cells. Two independent ELK4 datasets done from duplicate HEK293 cells. One endogenous Kap1 dataset and one Input dataset from a stable cell line derived from U2OS cells.
2011-05-24 | E-GEOD-27929 | biostudies-arrayexpress
Project description:Histone H3 lysine 9 methylation (H3K9me) mediates heterochromatic gene silencing and is important for genome stability and the regulation of gene expression. The establishment and epigenetic maintenance of heterochromatin involve the recruitment of H3K9 methyltransferases to specific sites on DNA, followed by the recognition of pre-existing H3K9me by the methyltransferase and methylation of proximal histone H3. This positive feedback loop must be tightly regulated to prevent deleterious epigenetic gene silencing. Extrinsic anti-silencing mechanisms involving histone demethylation or boundary elements help limit the spread of inappropriate H3K9me. However, how H3K9 methyltransferase activity is locally restricted or prevented from initiating random H3K9me—which would lead to aberrant gene silencing and epigenetic instability—is not fully understood. Here we reveal an autoinhibited conformation in the conserved H3K9 methyltransferase Clr4 (Suv39h) of the fission yeast Schizosaccharomyces pombe that has a critical role in preventing aberrant heterochromatin formation. Biochemical and X-ray crystallographic data show that an internal loop in Clr4 inhibits the catalytic activity of this enzyme by blocking the histone H3K9 substrate-binding pocket, and that automethylation of specific lysines in this loop promotes a conformational switch that enhances the H3K9me activity of Clr4. Mutations that are predicted to disrupt this regulation lead to aberrant H3K9me, loss of heterochromatin domains, and growth inhibition, demonstrating the importance of the intrinsic inhibition and auto-activation of Clr4 in regulating the deposition of H3K9me and in preventing epigenetic instability. Together, conservation of the Clr4 autoregulatory loop in other H3K9 methyltransferases and the automethylation of a corresponding lysine in the human SUV39H2 homologue suggest that the mechanism described here is broadly conserved.
2018-07-17 | GSE102905 | GEO
Project description:Swi6/HP1, an evolutionarily conserved protein, is critical for heterochromatin assembly in fission yeast and higher eukaryotes. In fission yeast, histone deacetylation by histone deacetylases is thought to be followed by H3-Lys-9 methylation by the histone methyltransferase Clr4/Suv39H1. H3-Lys-9-Me2 interacts with the chromodomain of Swi6/HP1. Swi6/HP1 is thought to act downstream of Clr4/Suv39, and further self-association of Swi6/HP1 is assumed to stabilize the heterochromatin structure. Here, we show that the self-association-defective mutant of Swi6 does not interact with Clr4. It not only fails to localize to heterochromatin loci but also interferes with heterochromatic localization of H3-Lys-9-Me2 (and thereby Clr4) and the endogenous Swi6 in a dominant negative manner. Thus, self-association of Swi6/HP1 helps in binding to and recruitment of Clr4 and thereby in establishment and maintenance of heterochromatin by a concerted rather than a sequential mechanism.
| S-EPMC3058978 | biostudies-literature