Chip-chip of condensin subunits Brn1 and Smc4 and Scc2/4 and cohesin and Tfc3 (TFIIIC) on budding yeast chromosomes
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ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe Saccharomyces cerevisiae
PROVIDER: GSE12149 | GEO | 2008/07/21
SECONDARY ACCESSION(S): PRJNA113761
REPOSITORIES: GEO
Similar Datasets
Project description:The condensin complex is well known to be essential for correct packaging and segregation of chromosomes during mitosis and meiosis in all eukaryotes. To date, the genome wide location and the nature of condensin binding sites has remained elusive in vertebrate systems. A detailed knowledge of condensin binding sites is essential to understand the as-yet enigmatic function of this complex and to define its greater role in chromosome architecture. To address this, we have used next generation sequencing to map condensin I in chicken DT40 cells. Unexpectedly, we found condensin I binds predominately to promoter sequences in mitotic cells. We also found a striking enrichment at both centromeres and telomeres, highlighting the importance of the complex in chromosome segregation. Taken together, the results show condensin I is largely absent from heterochromatic regions. These results reveal for the first time the condensin I binding sites in the vertebrate genome, and demonstrate the importance of the complex in genome segregation and suggest a novel function in gene regulation. Condensin associated DNA from chicken DT40 cells were affinity purified using streptavidin and deep sequenced by Illumina Hiseq2000
2013-10-03 | E-GEOD-45552 | biostudies-arrayexpress
Project description:The condensin complex is well known to be essential for correct packaging and segregation of chromosomes during mitosis and meiosis in all eukaryotes. To date, the genome wide location and the nature of condensin binding sites has remained elusive in vertebrate systems. A detailed knowledge of condensin binding sites is essential to understand the as-yet enigmatic function of this complex and to define its greater role in chromosome architecture. To address this, we have used next generation sequencing to map condensin I in chicken DT40 cells. Unexpectedly, we found condensin I binds predominately to promoter sequences in mitotic cells. We also found a striking enrichment at both centromeres and telomeres, highlighting the importance of the complex in chromosome segregation. Taken together, the results show condensin I is largely absent from heterochromatic regions. These results reveal for the first time the condensin I binding sites in the vertebrate genome, and demonstrate the importance of the complex in genome segregation and suggest a novel function in gene regulation.
2013-10-03 | GSE45552 | GEO
Project description:Condensin complexes are highly conserved for chromosome compaction to ensure their faithful segregation in mitosis. However, little is known about the role of condensin complexes in interphase. Condensins exists in two complexes, condensins I and II, in higher eukayotic cells. During interphase, condensin II is predominantly localized in the nucleus throughout the cell cycle, whereas condensin I is localized at the cytoplasm in interphase. The distinct localization patterns suggest that condensin II, but not condensin I, may contribute to genome organization in interphase. Our results suggest that condensin II is associated with TFIIIC complex in vivo. The aim of these experiments is to unravel the dependency of each other on binding to chromatin.
2017-06-01 | GSE80034 | GEO
Project description:During mitosis, TATA-binding protein(TBP), which remains bound to DNA during mitosis, recruits PP2A and also interacts with a subunit of the condensin complex to allow efficient dephosphorylation and inactivation of condensin near these promoters to inhibit their compaction. These result suggest that TBP function is not only important for expression of genes transcribed bDuring mitosis, TATA-binding protein(TBP), which remains bound to DNA during mitosis, recruits PP2A and also interacts with a subunit of the condensin complex to allow efficient dephosphorylation and inactivation of condensin near these promoters to inhibit their compaction. These result suggest that TBP function is not only important for expression of genes transcribed by all three RNA polymerase during interphase, but also for transmitting the memory of gene activity through mitosis to daughter cellsy all three RNA polymerase during interphase, but also for transmitting the memory of gene activity through mitosis to daughter cells We use ChIP-chip approach to identify TBP-bindind sites in mitotic Jurkat cells at genome-wide level. Input DNA fragments and DNA fragments immunoprecipitated by TBP antibodies by ChIP assay on mitotic Jurkat cells were used to probe the Affymetrix Genechip human tiling 2.0c to identift TBP-binding sites in mitotic Jurkat cells. Input and ChIP sample were replicated three times as following: Input rep1, TBP ChIP1, Input rep2, TBP ChIP2, Input rep3, TBP ChIP3.
2010-04-03 | E-GEOD-12256 | biostudies-arrayexpress
Project description:Chip-chip of condensin subunits Brn1 and Smc4 and Scc2/4 and cohesin and Tfc3 (TFIIIC) on budding yeast chromosomes
| PRJNA113761 | ENA
Project description:Condensin complexes are highly conserved for chromosome compaction to ensure their faithful segregation in mitosis. However, little is known about the role of condensin complexes in interphase. Condensins exists in two complexes, condensins I and II, in higher eukayotic cells. During interphase, condensin II is predominantly localized in the nucleus throughout the cell cycle, whereas condensin I is localized at the cytoplasm in interphase. The distinct localization patterns suggest that condensin II, but not condensin I, may contribute to genome organization in interphase. Our results suggest that condensin II is associated with TFIIIC complex in humans.
2018-09-05 | GSE119418 | GEO
Project description:In addition to sharing with condensin an ability to organize DNA into chromatids, cohesin regulates enhancer-promoter interactions and confers sister chromatid cohesion. Association with chromosomes is regulated by hook-shaped HEAT repeat proteins that Associate With its Kleisin (Scc1) subunit (HAWKs), namely Scc3, Pds5, and Scc2. Unlike Pds5, Scc2 is not a stable cohesin constituent but, as shown here, transiently displaces Pds5 during loading. Scc1 mutations that compromise its interaction with Scc2 adversely affect cohesin’s ATPase activity, loading, and translocation while Scc2 mutations that alter how the ATPase responds to DNA abolish loading despite cohesin’s initial association with loading sites. Lastly, Scc2 mutations that permit loading in the absence of Scc4 increase Scc2’s association with chromosomal cohesin and reduce that of Pds5. We suggest that cohesin switches between two states, one with Pds5 bound to Scc1 that is not able to hydrolyse ATP efficiently but is capable of release from chromosomes and another in which Scc2, transiently replacing Pds5, stimulates the ATP hydrolysis necessary for loading and translocation away from loading sites.
2018-07-17 | GSE106182 | GEO
Project description:Cohesin holds sister chromatids together to enable their accurate segregation in mitosis. How, and where, cohesin binds to chromosomes are still poorly understood, and recent genome-wide surveys have revealed an apparent disparity between its chromosomal association patterns in different organisms. Here, we present the high-resolution analysis of cohesin localisation along fission yeast chromosomes. This reveals that several determinants, thought specific for distinct organisms, come together to shape the overall distribution. Cohesin is detected at chromosomal loading sites, characterised by the cohesin loader Mis4/Ssl3, in regions of strong transcriptional activity. Cohesin also responds to transcription by downstream translocation and accumulation at convergent transcriptional terminators surrounding the loading sites. As cells enter mitosis, a fraction of cohesin leaves chromosomes in a cleavage-independent reaction, while a substantial pool of cohesin dissociates when it is cleaved at anaphase onset. As a unique feature, centromeric cohesin spreads out onto chromosome arms during mitosis as the heterochromatin protein Swi6 dissociates from centromeres. Together, this allows us to suggest conserved mechanisms for chromosomal cohesin binding in eukaryotes. After DNA replication in S phase, sister chromatids are held together by the cohesin complex. This allows DNA break repair by homologous recombination in G2 and bipolar attachment of the spindle to sister kinetochores in mitosis. At anaphase onset, sister chromatid cohesion is resolved to trigger chromosome segregation. Cohesin is an essential, conserved protein complex consisting of at least five subunits, Psm1, Psm3, Rad21, Psc3 and Pds5 in fission yeast (orthologs of budding yeast Smc1, Smc3, Scc1, Scc3 and Pds5, respectively). Chromatin immunoprecipitations against three different subunits of the cohesin complex, fused to two different epitope tags (Rad21-Pk9 -> GSM333001, Rad21-HA3 -> GSM333004, Psc3-Pk9 -> GSM333005 and Pds5-Pk9 -> GSM333006), yielded a reproducible binding pattern between approximately half of all available convergently transcribed gene pairs (in the following called convergent sites). The pattern was almost indistinguishable between exponentially growing cell populations (GSM333004, GSM333005, GSM333006) and cells arrested in G2 using the thermosensitive cdc25-22 mutation (GSM333001). To understand why some, but not all, convergent sites are bound by cohesin, we analysed whether fission yeast cohesin responds to Pol II transcription by downstream translocation, like in budding yeast. As an example, we analysed cohesin at the convergent site between the rad21 and pof3 genes. rad21 expression is high during G1 and S phase, but low in G2. In cells arrested in G2 using the cdc25-22 allele, only a small cohesin peak was detectable that largely overlapped with the rad21 ORF (GSM333001). In contrast, in cells arrested in G1 using the cdc10-129 allele, the rad21 ORF was clear of cohesin and instead a large cohesin peak accumulated downstream of rad21 (GSM333007). It has been suggested that transcriptional readthrough at convergent sites promotes double stranded RNA-dependent heterochromatin formation, which in turn underlies cohesin recruitment. We therefore tested whether the heterochromatin protein Swi6, thought to recruit cohesin, played a role in generating the observed cohesin pattern. We grew wild type and swi6Î cells in synthetic medium lacking thiamine, conditions under which the nmt2 gene is transcribed at the nmt2/avn2 convergent site that has been studied as an example. In contrast to the prediction, the cohesin pattern along chromosome arms, including the nmt2/avn2 convergent site, remained unchanged in swi6Î cells (GSM333008). We detected only small amounts of cohesin at the nmt2/avn2 convergent site, a class 1 convergent site following the above classification. At the centromeric repeats, cohesin levels were reduced in the absence of Swi6. These findings are consistent with previous reports implicating Swi6 in cohesin recruitment to centromeric heterochromatin, but not chromosome arms. To compare cohesinâs pattern to its likely sites of chromosomal loading, we analysed the localisation of the cohesin loader subunits Mis4 and Ssl3. The two subunits showed a largely overlapping pattern of binding. Chromatin immunoprecipitation was performed against epitope-tagged Mis4-Pk9 (GSM333163) and Ssl3-Pk9 (GSM334196) from exponentially proliferating cells. As a control, cells without epitope-tagged protein were grown under identical conditions and processed in parallel for chromatin immunoprecipitation with an α-Pk antibody (GSM333230). The untagged control sample yielded trace amounts of immunoprecipitated DNA, which after amplification led to several strong peaks often in intergenic low complexity regions. Several of these peaks overlapped with Mis4/Ssl3 peaks, which were excluded from the analysis. Peaks in low complexity regions were not observed in chromatin immunoprecipitates of cohesin subunits (compare GSM333001). In the search for an underlying determinant of Mis4/Ssl3 binding sites, we noticed a striking correlation with tRNA and ribosomal protein genes. Mis4/Ssl3 binding sites at tRNA genes overlapped with the binding profile of the Pol III transcription factor TFIIIC subunit Sfc6 (GSM334198), while at ribosomal protein genes it colocalised with the forkhead domain containing protein Fhl1 (GSM334307). Fhl1 is a possible fission yeast ortholog of the transcription factor Fhl1 that controls ribosomal protein gene expression in budding yeast. We found Sfc6 also associated with ribosomal protein genes, and Fhl1 with tRNA genes, though with weaker signal intensities. We do not currently know whether Sfc6 contributes to transcriptional control of ribosomal protein genes, and Fhl1 to that of tRNA genes, or whether the weaker levels of association may reflect indirect association, mediated by interactions between ribosomal protein and tRNA gene loci. Similar to budding yeast, Mis4/Ssl3 binding sites are also binding sites for the chromosomal condensin complex (GSM334197), which may mediate such interactions. Having identified the binding sites of the Mis4/Ssl3 cohesin loader, we wanted to analyse its relationship with the cohesin distribution along chromosome arms. If Mis4/Ssl3 cohesin loading sites promote cohesin binding in their surrounding, deletion of a loading site should alter this pattern. To test this, we deleted a 489 bp sequence, containing two adjacent tRNA genes that form a Mis4/Ssl3 and cohesin binding site, on the left arm of chromosome 2. In response to the deletion, Mis4/Ssl3 binding to this locus disappeared (GSM334308). Cohesin was also no longer detected at this site (GSM334309), consistent with the notion that cohesin loading had been disrupted. However, the cohesin distribution at convergent sites surrounding the former loading site remained unchanged. This suggests that establishment of the cohesin pattern did not depend on a specific Mis4/Ssl3 binding site. Despite the tRNA deletion, residual Mis4/Ssl3 remained detectable in the vicinity of this site (GSM334308). Cohesin loading by Mis4/Ssl3 might therefore be less restricted to its peaks of binding than the pattern suggests. Alternatively, other determinants, e.g. gene orientation and their transcriptional activity, might define cohesin distribution at this locus. We next addressed how cohesin on fission yeast chromosomes responds to loss of sister chromatid cohesion during mitosis and whether cohesin removal in mitosis affected certain regions of the chromosome more than others. In order to follow cohesin through mitosis, we arrested a cell population in G2 using the thermosensitive cdc25-22 mutation and released the culture into synchronous mitotic progression at permissive temperature.The cohesin pattern remained largely unchanged throughout G2, metaphase and anaphase, although the height of peaks along chromosome arms decreased. This suggests that cohesin is not removed from a subset of its binding sites during mitosis, but that its association among most binding sites was uniformly reduced. A noticeable change to the cohesin pattern during mitosis became apparent around centromeres. Over a region of approximately 50 kb surrounding the centromeres, cohesin appeared to spread along chromosome arms, showing little preference for convergent sites. The spreading started as cells entered metaphase (GSM334316) and became most pronounced during anaphase (GSM334317). We also observed a similar, although less pronounced, spreading around centromeres in cells arrested in G1 using the cdc10-129 thermosensitive mutation (GSM333007). This suggests that spreading of cohesin around centromeres is cell cycle stage specific. Cohesin is enriched at the centromeric repeat regions (GSM333001), tethered by the heterochromatin protein Swi6, possibly after being loaded at core centromere sequences, where we observed strong Mis4/Ssl3 accumulation (GSM333163 & GSM334196). In mitosis, Swi6 levels are reduced after aurora B kinase-dependent phosphorylation of histone H3, and it reaccumulates as cells enter the subsequent S phase. To test whether loss of Swi6-dependent
2010-05-14 | E-GEOD-13517 | biostudies-arrayexpress
Project description:The experiment was performed to assess the importance of nucleosome eviction for the binding of condensin to chromatin during mitosis. The condensin complex associates with chromatin during mitosis to ensure chromosome condensation and accurate segregation, but how this binding is achieved remains poorly understood. Our study indicates that transcription co-activators Gcn5 and Mst2 assist condensin binding during mitosis by evicting nucleosomes. To reach this conclusion, we mapped nucleosomes, during mitosis, in wild-type and gcn5mst2 mutant strains. This experiment allowed us (1) to identify nucleosome-depleted regions (ndrs) during mitosis and to show that condensin tends to colocalize with ndr at the 3ends of genes, and (2) to confirm the importance of nucleosome eviction from ndrs by gcn5 and mst2, during mitosis, for the binding of condensin to chromatin.this experiment determines the patterns of nucleosomes in wild type and mutant fission yeast cells arrested in early mitosis. We analysed wild-type cells, cells lacking Gcn5 histone acetylatransferase (gcn5D) and cells lacking both Gcn5 and Mst2 histone acetyltransferases (Gcn5Dmst2D). All cells used in this study expressed a GFP-tagged version of condensin (Cnd2-GFP) and were blocked in early mitosis at 19C by the nda3-KM311 mutation. Mitotic indexes were determined by scoring the accumulation of Cnd2-GFP in the nucleus. Mitotic cells were collected and chromatin was digested by increasing amount of MNase to produce mononucleosomes. Mononucleosomal DNA was purified on an agarose gel and sequence on an Illumina Nextseq 500 apparatus. Three replicates of wild type, gcn5D and gcn5Dmst2D were analysed. Nucleosome patterns were determined in wild-type cells, cells lacking Gcn5 and cells lacking both Gcn5 and Mst2.
2016-04-18 | E-MTAB-4620 | biostudies-arrayexpress
Project description:Condensin mediates chromosome condensation, which is essential for proper chromosome segregation during mitosis. Prior to anaphase of budding yeast, the ribosomal DNA (RDN) condenses to a thin loop that is distinct from the rest of the chromosomes. We provide evidence that the establishment and maintenance of this RDN condensation require the regulation of condensin by Cdc5p (polo) kinase. We show that Cdc5p is recruited to the site of condensin binding in the RDN by cohesin, a complex related to condensin. Cdc5p and cohesin prevent condensin from misfolding the RDN into an irreversibly decondensed state. From these and other observations, we propose that the spatial regulation of Cdc5p by cohesin modulates condensin activity to ensure proper RDN folding into a thin loop. This mechanism may be evolutionarily conserved, promoting the thinly condensed constrictions that occur at centromeres and RDN of mitotic chromosomes in plants and animals.
2020-05-03 | GSE147290 | GEO