We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Multiple Bromodomain Genes Are Involved in Restricting the Spread of Heterochromatic Silencing at the Saccharomyces cerevisiae HMR-tRNA Boundary.
- Authors
Jambunathan, Nithya; Martinez, Adam W.; Robert, Elizabeth C.; Agochukwu, Nneamaka B.; Ibos, Megan E.; Dugas, Sandra L.; Donze, David
- Abstract
The transfer RNA gene downstream from the HMR locus in S. cerevisiae functions as part of a boundary (barrier) element that restricts the spread of heterochromatic gene silencing into the downstream region of chromosome III. A genetic screen for identifying additional genes that, when mutated, allow inappropriate spreading of silencing from HMR through the tRNA gene was performed. YTA7, a gene containing bromodomain and ATPase homologies, was identified multiple times. Previously, others had shown that the bromodomain protein Bdf1p functions to restrict silencing at yeast euchromatin- heterochromatin boundaries; therefore we deleted nonessential bromodomain-containing genes to test their effects on heterochromatin spreading. Deletion of PSC2, coding for a component of the RSC chromatin-remodeling complex, resulted in a significant spread of silencing at HMR. Since the bromodomain of YTA7 lacks a key tyrosine residue shown to be important for acetyllysine binding in other bromodomains, we confirmed that a GST-Yta7p bromodomain fusion was capable of binding to histones in vitro. Epistasis analysis suggests that YTA7 and the HMR-tRNA function independently to restrict the spread of silencing, while RSG2 may function through the tRNA element. Our results suggest that multiple bromodomain proteins are involved in restricting the propagation of heterochromatin at HMR.
- Subjects
SACCHAROMYCES cerevisiae; TRANSFER RNA; GENE silencing; CHROMOSOMES; CHROMATIN
- Publication
Genetics, 2005, Vol 171, Issue 3, p913
- ISSN
0016-6731
- Publication type
Article
- DOI
10.1534/genetics.105.046938