Reference: Lynch PJ and Rusche LN (2010) An auxiliary silencer and a boundary element maintain high levels of silencing proteins at HMR in Saccharomyces cerevisiae. Genetics 185(1):113-27

Reference Help

Abstract


Heterochromatin is notable for its capacity to propagate along a chromosome. The prevailing model for this spreading process postulates that silencing proteins are first recruited to silencer sequences and then spread from these sites independently of the silencers. However, we found that in Saccharomyces cerevisiae silencers also influence the extent of silenced chromatin domains. We compared the abilities of two different silencers, HMR-E and a telomeric repeat, to promote silencing and found that the HMR-E silencer contributed to an increased steady-state association of Sir proteins over a region of several kilobase-pairs compared to the telomeric repeat, even though both silencers recruited similar levels of Sir proteins. We also discovered that, although the HMR-E silencer alone was sufficient to block transcription of the HMR locus, a secondary silencer, HMR-I, boosted the level of Sir proteins at HMR, apparently beyond the level necessary to repress transcription. Finally, we discovered that a tRNA(Thr) gene near HMR-I helped maintain silenced chromatin and transcriptional repression under conditions of reduced deacetylase activity. This study highlights the importance of auxiliary elements, such as HMR-I and the tRNA(Thr) gene, in enhancing the association of Sir silencing proteins with appropriate genomic locations, thereby buffering the capacity of silenced chromatin to assemble under suboptimal conditions.

Reference Type
Journal Article
Authors
Lynch PJ, Rusche LN
Primary Lit For
Additional Lit For
Review For

Interaction Annotations


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Type Assay Annotation Action Modification Phenotype Source Reference

Gene Ontology Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Gene Ontology Term Qualifier Aspect Method Evidence Source Assigned On Annotation Extension Reference

Phenotype Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Regulation Annotations


Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Experiment Assay Construct Conditions Strain Background Reference