title: Sub-telomeric core X and Y' elements in S. cerevisiae suppress extreme variations in gene silencing.
abstract: Telomere Position Effect (TPE) is governed by strong repression signals emitted by telomeres via the Sir2/3/4 Histone Deacetylase complex. These signals are then relayed by weak proto-silencers residing in the subtelomeric core X and Y' elements. Subtelomeres also contain Sub-Telomeric Anti-silencing Regions (STARs). In this study we have prepared telomeres built of different combinations of core X, Y' and STARs and have analyzed them in strains lacking Histone-Acetyltransferase genes as well as in cdc6-1 and Δrif1 strains. We show that core X and Y' dramatically reduce both positive and negative variations in TPE, that are caused by these mutations. We also show that the deletion of Histone-Acetyltransferase genes reduce the silencing activity of an ACS proto-silencer, but also reduce the anti-silencing activity of a STAR. We postulate that core X and Y' act as epigenetic "cushioning" cis-elements.
authors: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
authors: Patricia
authors: P
authors: Power
authors: Daniel
authors: D
authors: Jeffery
authors: Muhammad Attiq
authors: MA
authors: Rehman
authors: Arjun
authors: A
authors: Chatterji
authors: Krassimir
authors: K
authors: Yankulov
mesh_terms: D001483:Base Sequence; D055012:Chromosomal Position Effects / Q000235:genetics; D017353:Gene Deletion; D020868:Gene Silencing; D005800:Genes, Fungal / Q000235:genetics; D051548:Histone Acetyltransferases / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D016615:Telomere / Q000235:genetics*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D051548:Histone Acetyltransferases