Schizosaccharomyces pombe
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA100363 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Mediator promotes CENP-A incorporation at fission yeast centromeres [ChIP-seq]
| PRJNA156087 | ENA
Project description:DNA topoisomerase III localizes to centromeres and affects centromeric CENP-A levels in fission yeast
| PRJNA189154 | ENA
Project description:The N-terminal Tail of CENP-A Confers Epigenetic Stability to Centromeres via the CENP-T Branch of the CCAN in Fission Yeast
| PRJNA267552 | ENA
Project description:Factors that promote H3 chromatin integrity during transcription prevent promiscuous deposition of CENP-A(Cnp1) in fission yeast
| PRJNA275892 | ENA
Project description:Epigenetically induced paucity of histone H2A.Z stabilizes fission yeast ectopic centromeres
| PRJNA158255 | ENA
Project description:A high-resolution map of inner kinetochore proteins in fission yeast regional centromeres
| PRJNA270660 | ENA
Project description:A defining feature of centromeres is the presence of the histone H3 variant CENP-ACnp1. It is not known how CENP-ACnp1 is specifically delivered to, and assembled into centromeric chromatin. Through a screen for factors involved in kinetochore integrity in fission yeast we identified Sim3. Sim3 is homologous to known histone binding proteins NASPHuman and N1/N2Xenopus and aligns with Hif1S.cerevisiae to define the SHNi-TPR family. Sim3 associates with CENP-ACnp1 but is distributed throughout the nucleoplasm rather than being concentrated at centromeres. Cells defective in Sim3 function have reduced levels of CENP-ACnp1 at centromeres and display chromosome segregation defects. Newly synthesized CENPACnp1 can be deposited at centromeres by a replication-independent mechanism during G2. Sim3 is required to allow this new CENP-ACnp1 to accumulate at centromeres in S and G2-phase arrested cells. We propose that Sim3 acts as an escort which hands off CENP-ACnp1 to chromatin assembly factors, allowing its incorporation into centromeric chromatin. Keywords: Expression of sim3-143 versus wt and sim3-205 versus wt
2007-11-10 | GSE7560 | GEO
Project description:Specialized chromatin containing CENP-A nucleosomes instead of H3 nucleosomes is found at all centromeres. However, the mechanisms that specify the locations at which CENP-A chromatin is assembled remain elusive in organisms with regional, epigenetically regulated centromeres. It is known that normal centromeric DNA is transcribed in several systems including the fission yeast, Schizosaccharomyces pombe. Here, we show that factors which preserve stable histone H3 chromatin during transcription also play a role in preventing promiscuous CENP-A(Cnp1) deposition in fission yeast. Mutations in the histone chaperone FACT impair the maintenance of H3 chromatin on transcribed regions and promote widespread CENP-A(Cnp1) incorporation at non-centromeric sites. FACT has little or no effect on CENP-A(Cnp1) assembly at endogenous centromeres where CENP-A(Cnp1) is normally assembled. In contrast, Clr6 complex II (Clr6-CII; equivalent to Rpd3S) histone deacetylase function has a more subtle impact on the stability of transcribed H3 chromatin and acts to prevent the ectopic accumulation of CENP-A(Cnp1) at specific loci, including subtelomeric regions, where CENP-A(Cnp1) is preferentially assembled. Moreover, defective Clr6-CII function allows the de novo assembly of CENP-A(Cnp1) chromatin on centromeric DNA, bypassing the normal requirement for heterochromatin. Thus, our analyses show that alterations in the process of chromatin assembly during transcription can destabilize H3 nucleosomes and thereby allow CENP-A(Cnp1) to assemble in its place. We propose that normal centromeres provide a specific chromatin context that limits reassembly of H3 chromatin during transcription and thereby promotes the establishment of CENP-A(Cnp1) chromatin and associated kinetochores. These findings have important implications for genetic and epigenetic processes involved in centromere specification. In total, 24 samples: 22 ChIP DNA files (10 different conditions), 2 Input files.
2015-02-19 | E-GEOD-66106 | biostudies-arrayexpress
Project description:The centromere is the location on each chromosome that directs the assembly of the kinetochore. The underlying hallmark of centromeres in most eukaryotes is the presence of specialised nucleosomes in which canonical histone H3 is replaced by the histone H3 variant CENP-A. The molecular events that mediate a programme to install CENP-A in place of histone H3, at centromeres and how the centromeric chromatin is reorganised for CENP-A assembly during cell cycle remain poorly characterised. Histone H2A variant, H2A.Z is linked to transcriptional competence, in maintaining heterochromatin silencing and enriched in CENP-A chromatin. Our analyses demonstrate that H2A.ZPht1 and the Swr1 complex are associated with CENP-ACnp1 chromatin in fission yeast. Swr1 and Msc1 regulate H2A.ZPht1 deposition at centromeres and along with H2A.ZPht1 maintain CENP-ACnp1 chromatin integrity. Additionally, they coordinate the deposition of CENP-ACnp1 through the cell cycle, coupled with eviction of histone H3 from centromeres. Based on our results, we propose that the centromere is programmed to the widespread incorporation of H2A.ZPht1 via Swr1, and that H2A.ZPht1 dynamics likely play a role in regulating centromeric chromatin by influencing CENP-A incorporation.
2020-12-01 | GSE106585 | GEO
Project description:We use high-resolution chemical cleavage mapping and both native and cross-linked chromatin immunoprecipitation with paired-end sequencing to elucidate the profile of nuceleosomes containing the centromere-specific variant of H3 (cenH3), known as CENP-A or Cnp1 in fission yeast. We find that in the central domain of fission yeast centromeres H3 nucleosomes are nearly absent and CENP-A nucleosomes are more widely spaced that nucleosomes elsewere. CENP-A (Cnp1), CENP-C (Cnp3), CENP-T (Cnp20) and CENP-I (Mis6) are highly enriched at every position in the central domain except at tRNA genes, with weak enrichment in the flanking heterochromatin where these proteins show no evidence of the positioning that has been seen in point centromeres and in the satellite-rich centromeres of plants and animals. Our findings suggest that classical regional centromeres are distinguished from other centromere classes by the absence of cenH3 nucleosome positioning.
2015-08-17 | GSE64294 | GEO