Publication Date:
1993-12-17
Description:
In Saccharomyces cerevisiae, the HMR-E silencer blocks site-specific interactions between proteins and their recognition sequences in the vicinity of the silencer. Silencer function is correlated with the firing of an origin of replication at HMR-E. An essential gene with a role in transcriptional silencing was identified by means of a screen for mutations affecting expression of HMR. This gene, known as ORC2, was shown to encode a component of the origin recognition complex that binds yeast origins of replication. A temperature-sensitive mutation in ORC2 disrupted silencing in cells grown at the permissive temperature. At the restrictive temperature, the orc2-1 mutation caused cell cycle arrest at a point in the cell cycle indicative of blocks in DNA replication. The orc2-1 mutation also resulted in the enhanced mitotic loss of a plasmid, suggestive of a defect in replication. These results provide strong evidence for an in vivo role of ORC in both chromosomal replication and silencing, and provide a link between the mechanism of silencing and DNA replication.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Foss, M -- McNally, F J -- Laurenson, P -- Rine, J -- GM31105/GM/NIGMS NIH HHS/ -- P30ES01896-12/ES/NIEHS NIH HHS/ -- New York, N.Y. -- Science. 1993 Dec 17;262(5141):1838-44.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Biology, University of California, Berkeley 94720.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8266071" target="_blank"〉PubMed〈/a〉
Keywords:
Alleles
;
Amino Acid Sequence
;
Cell Cycle
;
Cloning, Molecular
;
*DNA Replication
;
DNA, Fungal/genetics/metabolism
;
*DNA-Binding Proteins
;
Fungal Proteins/chemistry/*genetics/metabolism
;
*Gene Expression Regulation, Fungal
;
*Genes, Fungal
;
Molecular Sequence Data
;
Mutation
;
Origin Recognition Complex
;
Phenotype
;
Plasmids
;
*Replicon
;
Repressor Proteins/chemistry/*genetics/metabolism
;
Saccharomyces cerevisiae/cytology/*genetics/metabolism
;
Saccharomyces cerevisiae Proteins
;
Transcription, Genetic
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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