Schizosaccharomyces pombe
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA383112 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Epigenetic adaptation to uncontrolled heterochromatin spreading
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Project description:Leo1 is a Global Regulator of Heterochromatin Cis-spreading
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Project description:The 19S proteasome regulates subtelomere silencing and facultative heterochromatin formation
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Project description:Roles of the Clr4 methyltransferase complex in nucleation, spreading and maintenance of heterochromatin
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Project description:The 19S proteasome subunit Rpt3 regulates distribution of CENP-A by associating with centromeric chromatin
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Project description:Domains of heterochromatin play important roles in the maintenance and regulation of eukaryotic genomes. However, the repressive nature of heterochromatin combined with its propensity to self-propagate necessitates the existence of robust mechanisms that limit heterochromatin spreading and thereby avoid silencing of expressed genes. A number of specific sequence elements have been found to serve as barriers to heterochromatin spreading; however, the mechanisms by which spreading is curtailed are generally not well understood. Here we uncover a role for PAF complex component Leo1 in regulating heterochromatin cis-spreading. A genetic screen revealed that loss of Leo1 results in spreading of heterochromatin across a centromeric (IRC) boundary element in fission yeast. Similar heterochromatin spreading was seen upon deletion of other components of the PAF complex, but not other factors involved in transcription-coupled chromatin modification, indicating a specific role for the PAF complex in heterochromatin regulation. Loss of Leo1 is associated with reduced levels of H4K16 acetylation at the boundary, while tethering of the H4K16 acetyltransferase Mst1 to boundary chromatin suppresses heterochromatin spreading in leo1? cells, suggesting that Leo1 antagonises heterochromatin spreading by facilitating H4K16 acetylation. Interestingly, Leo1 also regulates heterochromatin spreading independently of boundaries, and loss of Leo1 causes redistribution of heterochromatin, in particular resulting in substantial expansion of telomeric heterochromatin domains. The PAF complex is known to be an important regulator of transcription-related chromatin modifications; our findings reveal a previously undescribed role for this complex in global regulation of heterochromatin spreading in cis. 8 samples: input (whole cell extract) and IP from H3K9me2 ChIP in wild-type and leo1? cells, in duplicate
2015-05-22 | E-GEOD-61688 | biostudies-arrayexpress
Project description:Domains of heterochromatin play important roles in the maintenance and regulation of eukaryotic genomes. However, the repressive nature of heterochromatin combined with its propensity to self-propagate necessitates the existence of robust mechanisms that limit heterochromatin spreading and thereby avoid silencing of expressed genes. A number of specific sequence elements have been found to serve as barriers to heterochromatin spreading; however, the mechanisms by which spreading is curtailed are generally not well understood. Here we uncover a role for PAF complex component Leo1 in regulating heterochromatin cis-spreading. A genetic screen revealed that loss of Leo1 results in spreading of heterochromatin across a centromeric (IRC) boundary element in fission yeast. Similar heterochromatin spreading was seen upon deletion of other components of the PAF complex, but not other factors involved in transcription-coupled chromatin modification, indicating a specific role for the PAF complex in heterochromatin regulation. Loss of Leo1 is associated with reduced levels of H4K16 acetylation at the boundary, while tethering of the H4K16 acetyltransferase Mst1 to boundary chromatin suppresses heterochromatin spreading in leo1Δ cells, suggesting that Leo1 antagonises heterochromatin spreading by facilitating H4K16 acetylation. Interestingly, Leo1 also regulates heterochromatin spreading independently of boundaries, and loss of Leo1 causes redistribution of heterochromatin, in particular resulting in substantial expansion of telomeric heterochromatin domains. The PAF complex is known to be an important regulator of transcription-related chromatin modifications; our findings reveal a previously undescribed role for this complex in global regulation of heterochromatin spreading in cis.
2015-05-22 | GSE61688 | GEO
Project description:Role of 3' UTR in spreading of siRNAs
| PRJNA229168 | ENA
Project description:Proteins of the conserved HP1 family are elementary components of heterochromatin and are generally assumed to play a central role in creating a rigid heterochromatic network that is densely packed and inaccessible to the transcription machinery. In this study we demonstrate that the fission yeast HP1 protein Swi6 exists as a single highly dynamic population and rapidly exchanges in cis and in trans between different heterochromatic regions. Binding to methylated H3K9 or to heterochromatic RNA decelerates Swi6 mobility. We further show that Swi6 is largely dispensable to maintain heterochromatin domains. In contrast, our results disclose an unexpected role of Swi6 in demarcating constitutive heterochromatin from neighboring euchromatin. Our results are consistent with a stochastic model of heterochromatin and imply that heterochromatin is permissive for transcription throughout the cell cycle. Rather than promoting maintenance and spreading of heterochromatin, Swi6 appears to limit these processes to ensure that heterochromatin is appropriately confined.
2015-10-07 | GSE61136 | GEO
Project description:Loss of Epe1 enhances ectopic heterochromatin formation
| PRJDB6425 | ENA