GCN5 is a positive regulator of DNA replication origins in Saccharomyces cerevisiae

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Espinosa, Maria Claudia
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University of Guelph

The central role of chromatin modifying factors in the regulation of gene expression is well established, however little has been reported about how such factors are involved in DNA replication. 'GCN5' encodes one of the Histone Acetyl-transferases (HATs) genes in 'S. cerevisiae ' that functions as a coactivator in transcriptional regulation, and could also be implicated in centromere maintenance. Here I provide evidence that links Gcn5p with the regulation of DNA replication. I show that disruption of 'GCN5' decreases the stability of mini-chromosomes and that high copy of 'GCN5, TRA1' and 'SPT7' suppress the temperature sensitivity ('Ts') and mini-chromosome instability phenotypes characteristic of the replication mutants ' orc2-1, orc5-1' and 'mcm5-461.' Furthermore, I observed physical association between Gcn5p and origins of DNA replication, while its deletion leads to increased chromatin condensation at an origin of replication.

chromatin, regulation, gene expression, DNA replication, GCN5, Saccharomyces cerevisiae