<< Go Back

Metadata

Name
Silencing factors induce the elimination of nucleosome-free regions in S. pombe heterochromatin
Repository
Gene Expression Omnibus
Identifier
geo.series:GSE19596
Description
Abstract: In the yeast S. pombe, multiple chromatin-modifying enzymes are required for heterochromatin formation, yet how their actions alter chromatin structure to block access to DNAby the transcriptional machinery is unknown. We constructed high-resolution nucleosome occupancy maps of heterochromatic regions in wild-type strains and in mutants lacking the H3K9 methyltransferase Clr4 or one of the two activities of the silencing effector complex SHREC. Fourier analysis reveals that these enzymes do not increase the regularity of nucleosome spacing. Rather, their principal effect was to induce the elimination of nucleosome-free regions (NFRs). Both NFRs associated with transcription initiation sites as well as those not associated with promoters are affected. As in S. cerevisiae, repressed genes in euchromatin retain their NFRs. Thus, NFR elimination cannot be explained as a secondary consequence of repression. The maps also show that TFIIIC boundary elements have NFRs resistant to silencing, suggesting a potential
role in preventing lateral spread of heterochromatin. NFR elimination offers a mechanism by which heterochromatin restricts access of the transcriptional machinery to DNA.
Data or Study Types
Expression profiling by genome tiling array, Genome binding/occupancy profiling by genome tiling array
Source Organization
National Center for Biotechnology Information
Access Conditions
available
Year
2010
Access Hyperlink
http://www.ncbi.nlm.nih.gov/sites/GDSbrowser?acc=GSE19596

Distributions