Condensin-mediated remodeling of the mitotic chromatin landscape in fission yeast
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ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE94478 | GEO | 2017/07/13
SECONDARY ACCESSION(S): PRJNA369801
REPOSITORIES: GEO
Similar Datasets
Project description:The eukaryotic genome consists of DNA molecules far longer than the cells that contain them. They reach their greatest compaction during chromosome condensation in mitosis. This process is aided by condensin, a structural maintenance of chromosomes (SMC) family member. The spatial organization of mitotic chromosomes and how condensin shapes chromatin architecture are not yet fully understood. Here we use chromosome conformation capture (Hi-C) to study mitotic chromosome condensation in the fission yeast Schizosaccharomyces pombe. This showed that the interphase landscape characterized by small chromatin domains is replaced by fewer but larger domains in mitosis. Condensin achieves this by setting up longer-range, intrachromosomal DNA interactions, which compact and individualize chromosomes. At the same time, local chromatin contacts are constrained by condensin, with profound implications for local chromatin function during mitosis. Our results highlight condensin as a major determinant that changes the chromatin landscape as cells prepare their genomes for cell division.
| S-EPMC5621628 | biostudies-literature
Project description:Chromatin fibres dynamically change their organisation during cell cycle. In interphase nucleus, chromatin fibres are evenly distributed whereas their spatial occupancy are reorganised to form condensed chromosomes in mitosis. This process called chromosome condensation is necessary for an accomplishment of faithful chromosome segregation. One of the Structural Maintenance of Chromosomes complexes, Condensin, is indispensable for chromosome condensation. It remains, however, unknown how Condensin plays its role in shaping mitotic chromosome. Here we show that chromatin fibres change their interacting partners; short-range contacts in interphase nucleus are converted into long-range interactions to shape condensed chromosomes. This conversion of interactions among chromatin fibres results in the formation of larger domains within mitotic chromosomes. Condensin is solely in charge of the conversion and large domain formation in fission yeast mitosis. Our results show how fission yeast Condensin is involved in shaping mitotic chromosomes.
2017-07-13 | GSE94475 | GEO
Project description:Chromatin fibres dynamically change their organisation during cell cycle. In interphase nucleus, chromatin fibres are evenly distributed whereas their spatial occupancy are reorganised to form condensed chromosomes in mitosis. This process called chromosome condensation is necessary for an accomplishment of faithful chromosome segregation. One of the Structural Maintenance of Chromosomes complexes, Condensin, is indispensable for chromosome condensation. It remains, however, unknown how Condensin plays its role in shaping mitotic chromosome. Here we show that chromatin fibres change their interacting partners; short-range contacts in interphase nucleus are converted into long-range interactions to shape condensed chromosomes. This conversion of interactions among chromatin fibres results in the formation of larger domains within mitotic chromosomes. Condensin is solely in charge of the conversion and large domain formation in fission yeast mitosis. Our results show how fission yeast Condensin is involved in shaping mitotic chromosomes.
2017-07-13 | GSE94474 | GEO
Project description:Condensin-mediated remodeling of the mitotic chromatin landscape in fission yeast
| PRJNA369801 | ENA
Project description:BackgroundStructural maintenance of chromosomes (SMC) complexes are central organizers of chromatin architecture throughout the cell cycle. The SMC family member condensin is best known for establishing long-range chromatin interactions in mitosis. These compact chromatin and create mechanically stable chromosomes. How condensin contributes to chromatin organization in interphase is less well understood.ResultsHere, we use efficient conditional depletion of fission yeast condensin to determine its contribution to interphase chromatin organization. We deplete condensin in G2-arrested cells to preempt confounding effects from cell cycle progression without condensin. Genome-wide chromatin interaction mapping, using Hi-C, reveals condensin-mediated chromatin interactions in interphase that are qualitatively similar to those observed in mitosis, but quantitatively far less prevalent. Despite their low abundance, chromatin mobility tracking shows that condensin markedly confines interphase chromatin movements. Without condensin, chromatin behaves as an unconstrained Rouse polymer with excluded volume, while condensin constrains its mobility. Unexpectedly, we find that condensin is required during interphase to prevent ongoing transcription from eliciting a DNA damage response.ConclusionsIn addition to establishing mitotic chromosome architecture, condensin-mediated long-range chromatin interactions contribute to shaping chromatin organization in interphase. The resulting structure confines chromatin mobility and protects the genome from transcription-induced DNA damage. This adds to the important roles of condensin in maintaining chromosome stability.
| S-EPMC7643427 | biostudies-literature
Project description:The multiprotein Mediator complex is an important regulator of RNA polymerase II-dependent genes in eukaryotic cells. In contrast to the situation in many other eukaryotes, the conserved Med15 protein is not a stable component of Mediator isolated from fission yeast. We here demonstrate that Med15 exists in a protein complex together with Hrp1, a CHD1 ATP-dependent chromatin-remodeling protein. The Med15-Hrp1 subcomplex is not a component of the core Mediator complex but can interact with the L-Mediator conformation. Deletion of med15(+) and hrp1(+) causes very similar effects on global steady-state levels of mRNA, and genome-wide analyses demonstrate that Med15 associates with a distinct subset of Hrp1-bound gene promoters. Our findings therefore indicate that Mediator may directly influence histone density at regulated promoters.
| S-EPMC2943280 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2023-11-22 | GSE228402 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2013-01-01 | E-GEOD-26685 | biostudies-arrayexpress
Project description:Mitotic chromosome condensation is a prerequisite for the accurate segregation of chromosomes during cell division, and the conserved condensin complex a central player of this process. However, how condensin binds chromatin and shapes mitotic chromosomes remain poorly understood. Recent genome-wide binding studies showing that in most species condensin is enriched near highly expressed genes suggest a conserved link between condensin occupancy and high transcription rates. To gain insight into the mechanisms of condensin binding and mitotic chromosome condensation, we searched for factors that collaborate with condensin through a synthetic lethal genetic screen in the fission yeast Schizosaccharomyces pombe. We isolated novel mutations affecting condensin, as well as mutations in four genes not previously implicated in mitotic chromosome condensation in fission yeast. These mutations cause chromosome segregation defects similar to those provoked by defects in condensation. We also identified a suppressor of the cut3-477 condensin mutation, which largely rescued chromosome segregation during anaphase. Remarkably, of the five genes identified in this study, four encode transcription co-factors. Our results therefore provide strong additional evidence for a functional connection between chromosome condensation and transcription.
| S-EPMC3931570 | biostudies-literature
Project description:Long noncoding RNAs (lncRNAs) transcribed across gene promoters have been detected. These regulate transcription by mechanisms that have not been fully elucidated. We herein show that the chromatin configuration is altered into an accessible state within 290 bp downstream from the initiation site of metabolic-stress-induced lncRNAs (mlonRNAs) in the promoter of the fission yeast fbp1 gene, whose transcription is massively induced upon glucose starvation. Chromatin upstream from fbp1 is progressively altered into an open configuration, as a cascade of transcription of three overlapping mlonRNA species (-a, -b and -c in order) occurs with transcriptional initiation sites progressing 5' to 3' upstream of the fbp1 promoter. Initiation of the shortest mlonRNA (mlonRNA-c) induces chromatin remodeling around a transcription factor-binding site and subsequent massive induction of fbp1. We identify the cis-element required for mlonRNA-c initiation, and by changing the distance between mlonRNA-initiation site and the transcription factor-binding site, we show that mlonRNA-initiation effectively induces chromatin remodeling in a limited distance within 290 bp. These results indicate that mlonRNAs are transcribed across the fbp1 promoter as a short-range inducer for local chromatin alterations, and suggest that strict chromatin modulation is archived via stepwise mlonRNA-initiations.
| S-EPMC6342983 | biostudies-literature