Similar Datasets
Project description:H1 linker histones facilitate higher order chromatin folding and are essential for mammalian development. To achieve high resolution mapping of H1 variants H1d and H1c in embryonic stem cells (ESCs), we have established a knock-in system and shown that the N-terminally tagged H1 proteins are functionally interchangeable to their endogenous counterparts in vivo. H1d and H1c are depleted from GC- and gene-rich regions and active promoters, inversely correlated with H3K4me3, but positively correlated with H3K9me3 and associated with characteristic sequence features. Surprisingly, both H1d and H1c are significantly enriched at major satellites, which display increased nucleosome spacing compared with bulk chromatin. While also depleted at active promoters and enriched at major satellites, overexpressed H10 displays differential binding patterns in specific repetitive sequences compared with H1d and H1c. Depletion of H1c, H1d and H1e causes pericentric chromocenter clustering and de-repression of major satellites. These results integrate the localization of an understudied type of chromatin proteins, namely the H1 variants, into the epigenome map of mouse ESCs, and we identify significant changes at pericentric heterochromatin upon depletion of this epigenetic mark. Mapping linker histone H1 variants H1d, H1c and H10 as well as 3 core histone modifications in mouse ESC genome.
2013-04-29 | E-GEOD-46134 | biostudies-arrayexpress
Project description:The prominent role of pericentromeric Mbp block of 1.688 satellites in hybrid incompatibility, facilitating role of distributed X-linked 1.688 satellites in dosage compensation in males and being as a necessary element for POF recruitment to chromosome X in females led us to further investigate the role of 1.688 satellites and POF in chromosome-wide gene regulation by comparing RNA-seq data from the relevant mutants in comparison to wildtype.
2020-01-30 | GSE136637 | GEO
Project description:The densely packed centromeric heterochromatin at minor and major satellites is comprised of H3K9me2/3 histones, the heterochromatin protein HP1α and histone variants. In the present study we sought to determine the mechanisms by which condensed heterochromatin at major and minor satellites stabilized by the chromatin factor CFDP1 affects the activity of the small GTPase Ran as a requirement for spindle formation. CFDP1 co-localized with heterochromatin at major and minor satellites and was essential for the structural stability of centromeric heterochromatin. Loss of CENPA, HP1α and H2A.Z heterochromatin components resulted in decreased binding of the spindle nucleation facilitator RCC1 to minor and major satellite repeats. Decreased RanGTP levels as a result of diminished RCC1 binding interfered with chromatin-mediated microtubule nucleation at the onset of mitotic spindle formation. Rescuing chromatin H2A.Z levels in cells and mice lacking CFDP1 through knock-down of the histone chaperone ANP32E not only partially restored RCC1 dependent RanGTP levels but also alleviated CFDP1-knockout related craniofacial defects and increased microtubule nucleation in CFDP1/ANP32E co-silenced cells. Together, these studies provide evidence for a direct link between condensed heterochromatin at major and minor satellites and microtubule nucleation through the chromatin protein CFDP1.
2024-03-02 | GSE259307 | GEO
Project description:Centriolar satellites are an array of membrane-less granules that localize and move around the vertebrate centrosome/cilium complex. They have recently emerged as key regulators of the biogenesis and function of the centrosome/cilium-complex and their mutations are linked to ciliopathies. Although centriolar satellites are ubiquitous structures of the vertebrate cells, their precise function and molecular mechanism of action in different cell types remain poorly understood. Here, we generated kidney and retinal epithelial cells that lack centriolar satellites by genetically ablating their scaffolding protein PCM1 and investigated the cellular and molecular consequences of satellite loss in cells. We showed that centriolar satellites are required for cilium assembly, regulation of ciliary content, timely response to Hedgehog signals and three- dimensional epithelial cell organization, but not for cell proliferation, cell cycle progression and centriole duplication. Importantly, the requirement for centriolar satellites in cilium assembly varied between retinal and kidney epithelial cells and we identified the differences in the efficiency of targeting key ciliogenesis factors to the centrosome including Mib1 and Talpid3 as the likely molecular basis for this phenotypic variability. Quantitative global transcriptomic and proteomic profiling of satellite-less cells showed that loss of centriolar satellites does not lead to a major transcriptional response, but leads to a significant rearrangement of the global proteome. Together, our findings identify important roles for centriolar satellites in key cilium-related cellular processes through regulating the proteostasis and centrosomal/ciliary targeting of proteins and provide insight into the disease mechanisms of ciliopathies.
2018-11-28 | GSE123017 | GEO
Project description:Background: Global DNA methylation contributes to genomic integrity by supressing repeat associated transposition events. Several chromatin factors are required in addition to DNA methyltransferases to maintain DNA methylation at intergenic and satellite repeats. Embryos lacking Lsh, a member of the SNF2 superfamily of chromatin helicases, are hypomethylated. The interaction of Lsh with the de novo methyltransferase, Dnmt3b, facilitates the deposition of DNA methylation at stem cell genes. We wished to determine if a similar targeting mechanism operates to maintain DNA methylation at repetitive sequences. Results: We used HELP-seq to map genome wide DNA methylation patterns in Lsh-/- and Dnmt3b-/- somatic cells. DNA methylation is predominantly lost from specific genomic repeats in Lsh-/- cells: LTR-retrotransposons, LINE-1 repeats and mouse satellites. RNA-seq experiments demonstrate that specific IAP (Intracisternal A-type particle) LTRs and satellites, but not LINE-1 elements, are aberrantly transcribed inLsh-/- cells. LTR hypomethylation in Dnmt3b-/- cells is moderate and hypomethylated repetitive elements (IAP, LINE-1 and satellite) are silent. Chromatin immunoprecipitation (ChIP) indicates that repressed LINE-1 elements gain H3K4me3, but H3K9me3 levels are unaltered in Lsh-/- cells, indicating that DNA hypomethylation alone is not permissive for their transcriptional activation. Mis-expressed IAPs and satellites lose H3K9me3 and gain H3K4me3 in Lsh-/- cells. Conclusions: Our study emphasizes that regulation of repetitive elements by DNA methylation is selective and context dependent. We propose a model where Lsh is specifically required at a precise developmental window to target de novo methylation to repeat sequences, which is subsequently maintained by Dnmt1 in somatic cells to enforce repeat silencing thus contributing to genomic integrity. Two pairs of genomic samples compared: WT and Lsh-/- DNA isolations from tail-tip fibroblasts; WT and Dnmt3b knockout DNA isolations from mouse embryonic fibroblasts.
2013-12-09 | E-GEOD-52476 | biostudies-arrayexpress
Project description:H1 linker histones facilitate higher order chromatin folding and are essential for mammalian development. To achieve high resolution mapping of H1 variants H1d and H1c in embryonic stem cells (ESCs), we have established a knock-in system and shown that the N-terminally tagged H1 proteins are functionally interchangeable to their endogenous counterparts in vivo. H1d and H1c are depleted from GC- and gene-rich regions and active promoters, inversely correlated with H3K4me3, but positively correlated with H3K9me3 and associated with characteristic sequence features. Surprisingly, both H1d and H1c are significantly enriched at major satellites, which display increased nucleosome spacing compared with bulk chromatin. While also depleted at active promoters and enriched at major satellites, overexpressed H10 displays differential binding patterns in specific repetitive sequences compared with H1d and H1c. Depletion of H1c, H1d and H1e causes pericentric chromocenter clustering and de-repression of major satellites. These results integrate the localization of an understudied type of chromatin proteins, namely the H1 variants, into the epigenome map of mouse ESCs, and we identify significant changes at pericentric heterochromatin upon depletion of this epigenetic mark.
2013-04-29 | GSE46134 | GEO
Project description:Centrosomes are orbited by centriolar satellites, dynamic multiprotein assemblies nucleated by PCM1. To study the requirement for centriolar satellites, we generated mice lacking PCM1. Pcm1-/- mice display partially expressive perinatal lethality with survivors exhibiting hydrocephalus, oligospermia and cerebellar hypoplasia. Pcm1-/- multiciliated ependymal cells and PCM1-/- retinal pigmented epithelial 1 (RPE1) cells showed reduced ciliogenesis. PCM1-/- RPE1 cells displayed reduced docking of the mother centriole to the ciliary vesicle and removal of CP110 and CEP97 from the distal mother centriole, indicating compromised early ciliogenesis. We show these molecular cascades are maintained in vivo, although we propose that the cellular threshold for ciliogenesis initiation varies between cell types. We propose that PCM1 and centriolar satellites facilitate efficient trafficking of proteins to and from centrioles, including the departure of CP110 and CEP97 to initiate ciliogenesis.
2023-05-10 | PXD031920 | Pride
Project description:SILAC quantitative affinity purification experiment was performed to compare the protein composition of pericentriolar satellites in the wild-type and acentrosomal (stil KO) DT40 cell lines.
2019-05-30 | PXD011247 | Pride
Project description:Label-free quantitative affinity purification experiments were performed to identify the protein composition of pericentriolar satellites in the wild-type and two acentrosomal (stil KO; cep152 KO) DT40 cell lines.
2019-05-30 | PXD010325 | Pride
Project description:Drosophila melanogaster Heterochromatic 35x-bp Complex Satellites Assembly
| PRJNA594174 | ENA