CENP-B cooperates with Set1 in bidirectional transcriptional silencing and genome organization of retrotransposons
Ontology highlight
ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE39404 | GEO | 2012/10/12
SECONDARY ACCESSION(S): PRJNA170779
REPOSITORIES: GEO
Similar Datasets
Project description:Expression profiling of mutant cells compared to wild-type cells. Expression profiling of S. pombe CENP-B homolog cbp1M-bM-^HM-^F (abp1/SPBC1105.04c) and histone deacetylase double mutant clr3M-bM-^HM-^FM-BM- clr6-1 (SPBC800.03 SPBC36.05c) cells. Wildtype and mutant cDNA was reverse transcribed from total RNA using the Invitrogen SuperscriptIII Indirect labeling kit and the supplied anchored oligo-dT according to the manufacturer's instructions. cDNA from mutant and wildtype samples were labeled with Alexa Fluor 555 and 647 dyes, respectively. Biological duplicates were performed for each mutant and wildtype sample. An Agilent 44K in situ 60mer DNA microarray that tiles the entire Schizosaccharomyces pombe genome every 300 bp alternately on both strands was used to probe expression of transcripts in CENP-B homolog cbp1M-bM-^HM-^F (abp1/SPBC1105.04c) and histone deacetylase double mutants clr3M-bM-^HM-^F clr6-1 (SPBC800.03 SPBC36.05c) cells versus wildtype.
2012-10-12 | E-GEOD-39404 | biostudies-arrayexpress
Project description:Regulation of transposable elements (TEs) is critical to the integrity of the host genome. The fission yeast Schizosaccharomyces pombe homologs of mammalian CENP-B perform a host genome surveillance role by controlling Tf2 long terminal repeat (LTR) retrotransposons. However, the mechanisms by which CENP-Bs effect their functions are ill defined. Here, we show that the multifaceted roles of Abp1, the prominent member of fission yeast CENP-Bs, are mediated in part via recognition of a 10-bp AT-rich motif present in most LTRs and require the DNA-binding, transposase, and dimerization domains of Abp1 to maintain transcriptional repression and genome organization. Expression profiling analyses indicated that Abp1 recruits class I/II histone deacetylases (HDACs) to repress Tf2 retrotransposons and genes activated in response to stresses. We demonstrate that class I/II HDACs and sirtuins mediate the clustering of dispersed Tf2 retrotransposons into Tf bodies. Intriguingly, we uncovered an unexpected cooperation between Abp1 and the histone H3K4 methyltransferase Set1 in regulating sense and antisense transcriptional silencing of Tf2 retrotransposons and Tf body integrity. Moreover, Set1-mediated regulation of Tf2 expression and nuclear organization appears to be largely independent of H3K4 methylation. Our study illuminates a molecular pathway involving a transposase-containing transcription factor that cooperates with chromatin modifiers to regulate TE activities.
| S-EPMC3457346 | biostudies-literature
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: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.
2015-02-19 | GSE66106 | GEO
Project description:In Schizosaccharomyces pombe, Abp1 is homologous to mammalian CENP-B. Abp1 has various seemingly independent functions in the yeast nucleus. It binds to pericentromeric repeats and contribute to heterochromatin formation (ref). Abp1 is involved in regulating the directionality of mating-type switching by regulating the transcription of a member of the recombination-promoting complex (refs). Abp1 also preserves genome integrity by silencing the Tf2 retrotransposons and protecting replication forks during pausing (ref). The profile of the RNA extracted from abp1Δ cells shows an accumulation of RNA in size ranging between 100 and 200 bp. Solexa sequencing of these “little RNA” (liRNA) and comparison of their levels with the WT showed an increase in liRNA coming from various classes of genomic features. The biggest fold changes are attributed to liRNA coming from LTR retrotransposons and the rDNA genes repeats. We show that these liRNAs are targeted for degradation by the exosome and are the products of pervasive RNA Polymerase II transcription. Finally, we describe the genetic interactions of various transcriptional gene silencing effectors with the abp1 deletion in the silencing of the liRNA.
2016-07-08 | GSE81323 | GEO
Project description:In Schizosaccharomyces pombe, Abp1 is homologous to mammalian CENP-B. Abp1 has various seemingly independent functions in the yeast nucleus. It binds to pericentromeric repeats and contribute to heterochromatin formation (ref). Abp1 is involved in regulating the directionality of mating-type switching by regulating the transcription of a member of the recombination-promoting complex (refs). Abp1 also preserves genome integrity by silencing the Tf2 retrotransposons and protecting replication forks during pausing (ref). The profile of the RNA extracted from abp1Δ cells shows an accumulation of RNA in size ranging between 100 and 200 bp. Solexa sequencing of these “little RNA” (liRNA) and comparison of their levels with the WT showed an increase in liRNA coming from various classes of genomic features. The biggest fold changes are attributed to liRNA coming from LTR retrotransposons and the rDNA genes repeats. We show that these liRNAs are targeted for degradation by the exosome and are the products of pervasive RNA Polymerase II transcription. Finally, we describe the genetic interactions of various transcriptional gene silencing effectors with the abp1 deletion in the silencing of the liRNA.
2016-07-08 | GSE81280 | GEO
Project description:In Schizosaccharomyces pombe, Abp1 is homologous to mammalian CENP-B. Abp1 has various seemingly independent functions in the yeast nucleus. It binds to pericentromeric repeats and contribute to heterochromatin formation (ref). Abp1 is involved in regulating the directionality of mating-type switching by regulating the transcription of a member of the recombination-promoting complex (refs). Abp1 also preserves genome integrity by silencing the Tf2 retrotransposons and protecting replication forks during pausing (ref). The profile of the RNA extracted from abp1Δ cells shows an accumulation of RNA in size ranging between 100 and 200 bp. Solexa sequencing of these “little RNA” (liRNA) and comparison of their levels with the WT showed an increase in liRNA coming from various classes of genomic features. The biggest fold changes are attributed to liRNA coming from LTR retrotransposons and the rDNA genes repeats. We show that these liRNAs are targeted for degradation by the exosome and are the products of pervasive RNA Polymerase II transcription. Finally, we describe the genetic interactions of various transcriptional gene silencing effectors with the abp1 deletion in the silencing of the liRNA.
2016-07-08 | GSE81324 | GEO
Project description:We find that CENP-T acts as a bridge between two well-positioned CENP-A nucleosomes that are present on young alpha-satellite dimers that dominate functional human centromeres. CENP-T is centered over the CENP-B box, where it interacts with the CENP-B/CENP-C complex. Upon cross-linking, the entire CENP-A/CENP-C/CENP-T-containing complex is recovered as a nuclease-protected particle over an alpha-satellite dimer that comprises the fundamental unit of kinetochore chromatin. Our work reveals that CENP-A/CENP-C and CENP-T branches of kinetochore assembly are physically integrated.
2016-05-24 | GSE69839 | GEO
Project description:Gene expression profiling of S. pombe set1/COMPASS/H3K4 mutants, atf1 and set1 atf1 deletion mutants, set1 clr3 deletion mutants; ChIP-chip tiling microarray profiling of S. pombe Set1, Atf1, H3K4me3 in wt/atf1 deletion mutants, H3K9me2 in wt/set1 clr3 deletion mutants Custom Agilent 60mer microarrays were used to assay gene expression in set1/COMPASS mutants in combination with atf1 and clr3 mutants, and to profile genome-wide binding of Set1, Atf1, H3K4me3 and H3K9me2 in S. pombe cells (two-color mutant vs. wildtype, ChIP vs. input experiments).
2014-12-12 | E-GEOD-63301 | biostudies-arrayexpress
Project description:We employ the well-studied fission yeast centromere to investigate the function of the CENP-A (Cnp1) N-tail. We show that alteration of the N-tail did not affect Cnp1 loading at centromeres, outer kinetochore formation, or spindle checkpoint signaling, but nevertheless elevated chromosome loss. N-Tail mutants exhibited synthetic lethality with an altered centromeric DNA sequence, with rare survivors harboring chromosomal fusions in which the altered centromere was epigenetically inactivated. Elevated centromere inactivation was also observed for N-tail mutants with unaltered centromeric DNA sequences. N-tail mutants specifically reduced localization of the CCAN proteins Cnp20/CENP-T and Mis6/CENP-I, but not Cnp3/CENP-C. Overexpression of Cnp20/CENP-T suppressed defects in an N-tail mutant, suggesting a causal link between reduced CENP-T recruitment and the observed centromere inactivation phenotype. Thus, the Cnp1 N-tail promotes epigenetic stability of centromeres via recruitment of the CENP-T branch of the CCAN. Genome-wide localization of GFP-tagged N-tail Cnp1 variant tailswap versus wt control in cnp1 deletion background
2015-04-16 | E-GEOD-63350 | biostudies-arrayexpress