Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1996-7-22
pubmed:abstractText
Rap1p binds to silencer elements and telomeric repeats in yeast, where it appears to initiate silencing by recruiting Sir3p and Sir4p to the chromosome through interactions with its carboxy-terminal domain. Sir3p and Sir4p interact in vitro with histones H3 and H4 and are likely to be structural components of silent chromatin. We show that targeting of these Sir proteins to the chromosome is sufficient to initiate stable silencing either at a silent mating-type locus lacking a functional silencer element or at a telomere in a strain in which the Rap1p carboxy-terminal silencing domain has been deleted. Silencing by Sir protein targeting can also be initiated at a telomere-proximal site (ADH4), but is much weaker at an internal chromosomal locus (LYS2). Strikingly, deletion of the Rap1p silencing domain, which abolishes telomeric silencing, improves targeted silencing at LYS2 by both Sir3p and Sir4p, while weakening the silencing activity of these proteins at or near a telomere. This effect may result from the release of Sir proteins from the telomeres, thus increasing their effective concentration at other chromosomal sites. We suggest that telomeres and Rap1p serve a regulatory role in sequestering Sir proteins at telomeres, controlling silencing at other loci in trans and preventing indiscriminate gene silencing throughout the genome.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0890-9369
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1297-309
pubmed:dateRevised
2009-7-23
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Silencing of genes at nontelomeric sites in yeast is controlled by sequestration of silencing factors at telomeres by Rap 1 protein.
pubmed:affiliation
Department of Microbiology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't