Role of Fft3 in nuclear organization [MNase-seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE58012 | GEO | 2015/03/02
SECONDARY ACCESSION(S): PRJNA248690
REPOSITORIES: GEO
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Project description:In eukaryotic cells, local chromatin structure and chromatin organization in the nucleus both influence transcriptional regulation. At the local level, the Fun30 chromatin remodeler Fft3 is essential for maintaining proper chromatin structure at centromeres and subtelomeres in fission yeast. Using genome-wide mapping and live cell imaging, we show that this role is linked to controlling nuclear organization of its targets. In fft3M-NM-^T cells, subtelomeres lose their association with the LEM domain protein Man1 at the nuclear periphery and move to the interior of the nucleus. Furthermore, genes in these domains are upregulated and active chromatin marks increase. Fft3 is also enriched at retrotransposon-derived long terminal repeat (LTR) elements at the borders of subtelomeres and at tRNA genes. In cells lacking Fft3, these sites lose their peripheral positioning and show reduced nucleosome occupancy. We propose that Fft3 has a global role in mediating association between specific chromatin domains and components of the nuclear envelope by maintaining chromatin structure required for anchoring DNA insulators to nuclear pores. For MNase samples, duplicate mutant mononucleosome fractions were compared with duplicate WT mononucleosomes.
2015-03-02 | E-GEOD-58012 | biostudies-arrayexpress
Project description:In eukaryotic cells, local chromatin structure and chromatin organization in the nucleus both influence transcriptional regulation. At the local level, the Fun30 chromatin remodeler Fft3 is essential for maintaining proper chromatin structure at centromeres and subtelomeres in fission yeast. Using genome-wide mapping and live cell imaging, we show that this role is linked to controlling nuclear organization of its targets. In fft3M-NM-^T cells, subtelomeres lose their association with the LEM domain protein Man1 at the nuclear periphery and move to the interior of the nucleus. Furthermore, genes in these domains are upregulated and active chromatin marks increase. Fft3 is also enriched at retrotransposon-derived long terminal repeat (LTR) elements at the borders of subtelomeres and at tRNA genes. In cells lacking Fft3, these sites lose their peripheral positioning and show reduced nucleosome occupancy. We propose that Fft3 has a global role in mediating association between specific chromatin domains and components of the nuclear envelope by maintaining chromatin structure required for anchoring DNA insulators to nuclear pores. For DamID samples, we recorded methylation levels for Dam fusion proteins and compared them to Dam-only control samples. For ChIP samples, we compared immuno-precipitated DNA to mock or input controls.
2015-03-02 | E-GEOD-47464 | biostudies-arrayexpress
Project description:In eukaryotic cells, local chromatin structure and chromatin organization in the nucleus both influence transcriptional regulation. At the local level, the Fun30 chromatin remodeler Fft3 is essential for maintaining proper chromatin structure at centromeres and subtelomeres in fission yeast. Using genome-wide mapping and live cell imaging, we show that this role is linked to controlling nuclear organization of its targets. In fft3Δ cells, subtelomeres lose their association with the LEM domain protein Man1 at the nuclear periphery and move to the interior of the nucleus. Furthermore, genes in these domains are upregulated and active chromatin marks increase. Fft3 is also enriched at retrotransposon-derived long terminal repeat (LTR) elements at the borders of subtelomeres and at tRNA genes. In cells lacking Fft3, these sites lose their peripheral positioning and show reduced nucleosome occupancy. We propose that Fft3 has a global role in mediating association between specific chromatin domains and components of the nuclear envelope by maintaining chromatin structure required for anchoring DNA insulators to nuclear pores.
2015-03-02 | GSE47464 | GEO
Project description:The chromosomes of eukaryotes are organized into structurally and functionally discrete domains. This implies the presence of insulator elements that separate adjacent domains, allowing them to maintain different chromatin structures. We show that the Fun30 chromatin remodeler, Fft3, is essential for maintaining a proper chromatin structure at centromeres and subtelomeres. Fft3 is localized to insulator elements and inhibits euchromatin assembly in silent chromatin domains. In its absence, euchromatic histone modifications and histone variants invade centromeres and subtelomeres, causing a mis-regulation of gene expression and severe chromosome segregation defects. Our data strongly suggest that Fft3 controls the identity of chromatin domains by protecting these regions from euchromatin assembly.
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Project description:Chromatin Immunoprecipitation against the nuclear envelope protein LEM-2 to detect association to the nuclear periphery. LEM-2 ChIP was performed on early embryo fixed extracts for wild-type and two mutants that have altered position of a perinuclear chromatin reporter.
2015-12-11 | GSE74133 | GEO
Project description:Chromatin Immunoprecipitation against the nuclear envelope protein LEM-2 to detect association to the nuclear periphery. LEM-2 ChIP was performed on early embryo fixed extracts for wild-type and two mutants that have altered position of a perinuclear chromatin reporter. LEM-2 ChIP on early embryo chromatin extracts of three different genotypes: wild-type, met-2 set-25_delta_delta and cec-4_delta, in two independent biological replicas
2015-12-11 | E-GEOD-74133 | biostudies-arrayexpress
Project description:modENCODE_submission_3168 Although C. elegans was the first multicellular organism with a completely sequenced genome, how this genome is arranged within the nucleus is not known. By chromatin immunoprecipitation of the nuclear transmembrane protein LEM-2, we determined the regions of the C. elegans genome associated with the nuclear membrane. We found that large regions of several megabases on the left and right arms of each autosome were associated with the nuclear membrane. The center of each autosome was free of such interactions, suggesting these regions are largely looped out from the nuclear membrane. The X chromosome, unlike the autosomes, was associated with the nuclear membrane only at its left end. At a finer scale, these large membrane-associated domains consist of smaller subdomains of LEM-2 associations. These subdomains are characterized by a high density of repetitive sequences, a low density of genes, and high levels of H3K27 trimethylation. The subdomains were punctuated by gaps containing genes with high transcriptional activity. Finally, we found that a chromosome arm translocated to the center of a chromosome retained its association with the nuclear membrane, although there was a decrease of association up to 400 kb from the fusion point. This indicates that local chromatin properties are the main determinant of interaction with the nuclear membrane, but the degree of association can be modulated by position along the chromosome. Our data provide the foundation for a model of the spatial arrangement of C.elegans chromosomes within the nucleus. Supplemental materials are available online at http://www.genome.org . Microarray and high-throughput sequencing data are available online at modENCODE Data Coordinating Center website, http://206.108.121.120/submit/public/list . These dataset are designed to confirm ChIP-chip experiments. The three experiments listed consist of: (1) LEM-2 ChIP-seq (seq-SDQ3891_LEM2_N2_MXemb_1_A_EE8_KI021); (2) control IgG ChIP-seq (seq-AB46540_NIgG_N2_MXemb_2_A_EE1432); and (3)Input-seq (seq-NA_N2_MXemb_3_A_EE1432) For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf
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Project description:Mitosis entails global alterations to chromosome structure and nuclear architecture, concomitant with transient silencing of transcription. How cells transmit transcriptional states through mitosis remains incompletely understood. While many nuclear factors dissociate from mitotic chromosomes, the observation that certain nuclear factors and chromatin features remain associated with individual loci during mitosis originated the hypothesis that they could provide transcriptional memory through mitosis. To obtain the first genome-wide view of the dynamics of chromatin structure during mitosis, we compared the DNase sensitivity of interphase and mitotic chromatin at two stages of cellular maturation in a rapidly dividingmurine erythroblastmodel. Despite global chromosome condensation visible during mitosis at the microscopic level, the chromatin accessibility landscape is largely unaltered. However, mitotic chromatin accessibility is locally dynamic, with individual loci maintaining none, some, or all of their interphase accessibility. Mitotic reduction in accessibility occurs primarily within narrow, highly hypersensitive sites that frequently coincide with transcription factor binding sites, whereas broader domains of moderate accessibility tend to be more stable. In mitosis, proximal promoters generally maintain their accessibility, whereas distal regulatory elements preferentially lose accessibility. Promoters with the highest degree of accessibility preservation in mitosis tend to also be accessible across many murine tissues in interphase. Transcription factor GATA1 exerts site-specific changes in interphase accessibility that are most pronounced at distal regulatory elements, but does not visibly influence mitotic accessibility. We conclude that features of open chromatin are remarkably stable through mitosis and are modulated at the level of individual genes and regulatory elements. Dnase-Seq data is integrated with Chip-seq [GSE36589, GSE30142] and RNA-seq to examine epigentic changes in mitosis. We performed DNase-seq on two cell lines, G1E and G1E-ER4, both on an asynchronus population, and on a sample of cells in mitosis; each of the 4 experiments in triplicate.
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