Research Abstracts Online
2008 - March 2009
University of Minnesota Twin Cities
College of Biological Sciences and Medical School
Department of Biochemistry, Molecular Biology, and Biophysics
PI: Anja-Katrin Bielinsky
Investigations of Origin Activation and Stability Replication Forks in Saccharomyces cerevisiae
The budding yeast Saccharomyces cerevisiae activates the S phase checkpoint kinases mec1 and rad53 in the presence of replication stress due to replication fork stalling. In the absence of the checkpoint, fork collapse leads to incomplete DNA replication and chromosome breakage, which is detrimental to a cell. To gain insight into the mechanism by which the checkpoint coordinates DNA replication and fork stabilization, these researchers have previously analyzed origin activation genome-wide in the checkpoint mutants mec1 and rad53, and are currently doing the same with mrc1 and rad9 mutants. These studies will provide insight into the role of the checkpoint mediators in maintaining genome stability by regulating origin firing and stabilizing replication forks at fragile sites in yeast.
In a related project, the researchers are analyzing origin activation genome-wide in cdc9 (DNA ligase I) mutants in S. cerevisiae, to investigate replication fork progression in the presence of Okazaki fragment maturation defects. These studies will provide insight into the mechanism of how cells maintain genome stability when lagging strand DNA synthesis is compromised.
Hai Dang Nguyen, Graduate Student