Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Control of chromatin structure by Spt6 has different consequences in coding and regulatory regions

ABSTRACT: Spt6 is a highly conserved factor that carries out important functions in transcription and chromatin structure. To gain new insights into Spt6, we measured nucleosome occupancy along Saccharomyces cerevisiae chromosome III in an spt6 mutant and found that the level of nucleosomes is greatly reduced accross some but not all coding regions. In addition, genome-wide location analyses of RNA polymerase II showed that the nucleosome loss in the spt6 mutant occurs over highly-transcribed genes. Unexpectedly, the effects of the spt6 mutation on nucleosome levels did not correlate with its effects on mRNA levels, suggesting that Spt6 plays distinct roles in controlling chromatin structure across coding regions and in transcriptional regulation. We studied one case of transcriptional regulation by Stp6, at the CHA1 gene, and showed that regulation likely occurs by Spt6 controlling the position of the +1 nucleosome. These results, along with previous studies, suggest that Spt6 regulates transcription by controlling chromatin structure over regulatory regions, and its effects on nucleosome levels over coding regions likely serve and independent function.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE21787 | GEO | 2010/12/01

SECONDARY ACCESSION(S): PRJNA127315

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Shared Molecules

Only show the datasets with similarity scores above: 0.5

Threshold

0.5

Similar Datasets

Control of chromatin structure by Spt6 has different consequences in coding and regulatory regions

Project description:Spt6 is a highly conserved factor that carries out important functions in transcription and chromatin structure. To gain new insights into Spt6, we measured nucleosome occupancy along Saccharomyces cerevisiae chromosome III in an spt6 mutant and found that the level of nucleosomes is greatly reduced accross some but not all coding regions. In addition, genome-wide location analyses of RNA polymerase II showed that the nucleosome loss in the spt6 mutant occurs over highly-transcribed genes. Unexpectedly, the effects of the spt6 mutation on nucleosome levels did not correlate with its effects on mRNA levels, suggesting that Spt6 plays distinct roles in controlling chromatin structure across coding regions and in transcriptional regulation. We studied one case of transcriptional regulation by Stp6, at the CHA1 gene, and showed that regulation likely occurs by Spt6 controlling the position of the +1 nucleosome. These results, along with previous studies, suggest that Spt6 regulates transcription by controlling chromatin structure over regulatory regions, and its effects on nucleosome levels over coding regions likely serve and independent function. In order to examine the genome-wide localization of RNAPII and Spt6 in Saccharomyces cerevisiae, RNAPII and Spt6 along with associated DNA sequences were immunoprecipitated using anti-8WG16 and anti-HA antibodies, respectively. The RNAPII and Spt6 chromatin immunoprecipitation was performed in duplicate from WT cells as described below. The extracted DNA was hybridized to a DNA microarray containing an average of 4 probes per kilobase across the whole yeast genome. The combined datasets are available in the supplemental files of the related publication.

2010-12-01 | E-GEOD-21787 | biostudies-arrayexpress

Spt6 is required for heterochromatic silencing in the fission yeast Schizosaccharomyces pombe

Project description:Spt6 is a conserved factor, critically required for several transcription and chromatin related processes. We now show that Spt6 and its binding partner, Iws1, are required for heterochromatic silencing in Schizosaccharomyces pombe. Our studies demonstrate that Spt6 is required for silencing of all heterochromatic loci and that an spt6 mutant has an unusual combination of heterochromatic phenotypes compared to previously studied silencing mutants. Unexpectedly, we find normal nucleosome positioning over heterochromatin and normal levels of histone H3K9 dimethylation. However, we also find greatly reduced levels of H3K9 trimethylation, elevated levels of H3K14 acetylation, and reduced recruitment of several silencing factors. Our evidence suggests that Spt6 plays a role at both the transcriptional and post-transcriptional levels; in an spt6 mutant, RNA polymerase II (RNAPII) occupancy at the pericentric regions is only modestly increased, while production of small interfering RNAs (siRNAs) is lost. Taken together, our results suggest that Spt6 is required for multiple steps in heterochromatic silencing by controlling chromatin, transcriptional, and post-transcriptional processes.

2011-10-20 | E-MTAB-738 | biostudies-arrayexpress

Essential histone chaperones collaborate to regulate transcription and chromatin integrity

Project description:Histone chaperones are critical for controlling chromatin integrity during transcription, DNA replication, and DNA repair. We have discovered that the physical interaction between two essential histone chaperones, Spt6 and Spn1/Iws1, is required for transcriptional accuracy and nucleosome organization. To understand this requirement, we have isolated suppressors of an spt6 mutation that disrupts the Spt6-Spn1 interaction. Several suppressors are in a third essential histone chaperone, FACT, while another suppressor is in the transcription elongation factor Spt5/DSIF. The FACT suppressors weaken FACT-nucleosome interactions and bypass the requirement for Spn1, possibly by restoring a necessary balance between Spt6 and FACT on chromatin. In contrast, the Spt5 suppressor modulates Spt6 function in a Spn1-dependent manner. Despite these distinct mechanisms, both suppressors alleviate the nucleosome organization defects caused by disruption of the Spt6-Spn1 interaction. Taken together, we have uncovered a network in which histone chaperones and other elongation factors coordinate transcriptional integrity and chromatin structure.

2020-11-05 | GSE160821 | GEO

Spt6 regulates intragenic and antisense transcription, nucleosome positioning, and histone modifications genome-wide in fission yeast [RNA-seq]

Project description:Spt6 is a highly conserved histone chaperone that interacts directly with both RNA polymerase II and histones to regulate gene expression. To gain a comprehensive understanding of the requirements for this critical factor, we have performed genome-wide analyses of transcription, chromatin structure, and histone modifications in an S. pombe spt6 mutant. Our results demonstrate several dramatic changes to transcription and chromatin structure in the spt6 mutant, including an elevation of antisense transcripts at over 70 percent of all genes and general loss of the +1 nucleosome. Furthermore, Spt6 is required for the trimethylation of histone H3 on lysines 4 and 36, marks associated with active transcription. Taken together, our results indicate that Spt6 is critical for the accuracy of transcription and the integrity of chromatin, likely via its direct interactions with RNA polymerase II and histones. RNA-seq experiments were performed on wild type and spt6-1 strains in replicate

2013-10-09 | E-GEOD-49573 | biostudies-arrayexpress

Spt6 is required for the fidelity of promoter selectivity

Project description:Spt6 is a conserved factor that controls transcription and chromatin structure across the genome. Although viewed as an elongation factor, spt6 mutations allow transcription from within coding regions, suggesting that Spt6 also controls initiation. To comprehensively characterize the requirement for Spt6 in transcription, we have used four approaches: TSS-seq and TFIIB ChIP-nexus to assay transcription initiation, NET-seq to assay elongating RNAPII, and MNase-seq to assay nucleosome occupancy and positioning. Our results demonstrate that Spt6 represses transcription initiation at thousands of intragenic promoters. We characterize these intragenic promoters, and find some features conserved with genic promoters and other features that are distinct. Finally, we show that Spt6 regulates transcription initiation at most genic promoters and propose a model of initiation site competition to account for this. Together, our results demonstrate that Spt6 controls the fidelity of transcription initiation throughout the genome and reveal the magnitude of the potential for expressing alternative genetic information via intragenic promoters.

2018-11-01 | GSE115775 | GEO

Spt6 regulates intragenic and antisense transcription, nucleosome positioning, and histone modifications genome-wide in fission yeast [Mnase-seq]

Project description:Spt6 is a highly conserved histone chaperone that interacts directly with both RNA polymerase II and histones to regulate gene expression. To gain a comprehensive understanding of the requirements for this critical factor, we have performed genome-wide analyses of transcription, chromatin structure, and histone modifications in an S. pombe spt6 mutant. Our results demonstrate several dramatic changes to transcription and chromatin structure in the spt6 mutant, including an elevation of antisense transcripts at over 70 percent of all genes and general loss of the +1 nucleosome. Furthermore, Spt6 is required for the trimethylation of histone H3 on lysines 4 and 36, marks associated with active transcription. Taken together, our results indicate that Spt6 is critical for the accuracy of transcription and the integrity of chromatin, likely via its direct interactions with RNA polymerase II and histones. MNase-seq experiments were performed on wild type and spt6-1 strains in replicate at two different MNase concentrations

2013-10-09 | E-GEOD-49572 | biostudies-arrayexpress

The histone chaperone Spt6 is required for normal recruitment of the capping enzyme Abd1 to transcribed regions

Project description:The histone chaperone Spt6 is involved in promoting elongation of RNA polymerase II (RNAPII), maintaining chromatin structure, regulating co-transcriptional histone modifications, and controlling mRNA processing. These diverse functions of Spt6 are partly mediated through its interactions with RNAPII and other factors in the transcription elongation complex. In this study, we used mass spectrometry to characterize the differences in RNAPII interacting factors between wild-type cells and those depleted for Spt6, leading to the identification of proteins that depend on Spt6 for their interaction with RNAPII. The altered association of some of these factors could be attributed to changes in steady-state protein levels. However, Abd1, the mRNA cap methyltransferase, had decreased association with RNAPII after Spt6 depletion despite unchanged Abd1 protein levels, showing a requirement for Spt6 in mediating the Abd1-RNAPII interaction. Genome-wide studies showed that Spt6 is required for maintaining the level of Abd1 over transcribed regions, as well as the level of Spt5, another protein known to recruit Abd1 to chromatin. Abd1 levels were particularly decreased at the 5’ ends of genes after Spt6 depletion, suggesting a greater need for Spt6 in Abd1 recruitment over these regions. Together, our results show that Spt6 is important in regulating the composition of the transcription elongation complex and reveal a previously unknown function for Spt6 in the recruitment of Abd1.

2021-09-10 | GSE171953 | GEO

Spt6 regulates intragenic and antisense transcription, nucleosome positioning, and histone modifications genome-wide in fission yeast [ChIP-seq]

Project description:Spt6 is a highly conserved histone chaperone that interacts directly with both RNA polymerase II and histones to regulate gene expression. To gain a comprehensive understanding of the requirements for this critical factor, we have performed genome-wide analyses of transcription, chromatin structure, and histone modifications in an S. pombe spt6 mutant. Our results demonstrate several dramatic changes to transcription and chromatin structure in the spt6 mutant, including an elevation of antisense transcripts at over 70 percent of all genes and general loss of the +1 nucleosome. Furthermore, Spt6 is required for the trimethylation of histone H3 on lysines 4 and 36, marks associated with active transcription. Taken together, our results indicate that Spt6 is critical for the accuracy of transcription and the integrity of chromatin, likely via its direct interactions with RNA polymerase II and histones. ChIP-seq experiments were performed on wild type and spt6-1 strains on the following proteins: RNA polymerase II (Rpb1), Paf1 Complex (Ctr9), COMPASS (Swd1), Set2, Spt6, histones H2B and H3, histone modifications H3K4me3 and H3K36me3. Experiments were performed in replicates and matching inputs were also sequenced.

2013-10-09 | E-GEOD-49574 | biostudies-arrayexpress

The histone chaperone Spt6 coordinates histone H3K27 demethylation to regulate gene expression and myogenesis

Project description:Histone chaperones affect chromatin structure and gene expression through interaction with histones and RNA polymerase II (PolII). Here, we report that the histone chaperone Spt6 counteracts H3K27me3, an epigenetic mark deposited by the Polycomb Repressive Complex 2 (PRC2) and associated with transcriptional repression. We found that Spt6 is required for proper engagement and function of the H3K27 demethylase KDM6A (UTX) on muscle genes and regulates muscle gene expression and cell differentiation. ChIP-Seq experiments revealed an extensive genome-wide overlap of Spt6, PolII and KDM6A at transcribed regions that are devoid of H3K27me3. Mammalian cells and zebrafish embryos with reduced Spt6 display increased H3K27me3 and diminished expression of the master regulator MyoD, resulting in myogenic differentiation defects. As a confirmation for an antagonistic relationship between Spt6 and H3K27me3, inhibition of PRC2 permits MyoD re-expression in myogenic cells with reduced Spt6. Our data indicate that, through cooperation with PolII and KDM6A, Spt6 orchestrates removal of H3K27me3, thus effectively controlling developmental gene expression and cell differentiation. Examination of Spt6 and KDM6A levels in a skeletal muscle cells at various developmental stages

2013-04-01 | E-GEOD-44119 | biostudies-arrayexpress

Spt6 regulates intragenic and antisense transcription, nucleosome positioning, and histone modifications genome-wide in fission yeast [Mnase-seq]

2013-10-09 | GSE49572 | GEO