The Saccharomyces cerevisiae RAD9, RAD17 and RAD24 genes are required for suppression of mutagenic post-replicative repair during chronic DNA damage.

Publication Type:

Journal Article

Source:

DNA repair, Volume 9, Issue 7, p.824-34 (2010)

Keywords:

2010, cell cycle, Cell Cycle Proteins, Clinical Research Division, DNA Damage, DNA repair, DNA Replication, DNA-Binding Proteins, Flow Cytometry Core Facility, Intracellular Signaling Peptides and Proteins, mutagenesis, Nuclear Proteins, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Shared Resources, Suppression, Genetic

Abstract:

In Saccharomyces cerevisiae, a DNA damage checkpoint in the S-phase is responsible for delaying DNA replication in response to genotoxic stress. This pathway is partially regulated by the checkpoint proteins Rad9, Rad17 and Rad24. Here, we describe a novel hypermutable phenotype for rad9Delta, rad17Delta and rad24Delta cells in response to a chronic 0.01% dose of the DNA alkylating agent MMS. We report that this hypermutability results from DNA damage introduction during the S-phase and is dependent on a functional translesion synthesis pathway. In addition, we performed a genetic screen for interactions with rad9Delta that confer sensitivity to 0.01% MMS. We report and quantify 25 genetic interactions with rad9Delta, many of which involve the post-replication repair machinery. From these data, we conclude that defects in S-phase checkpoint regulation lead to increased reliance on mutagenic translesion synthesis, and we describe a novel role for members of the S-phase DNA damage checkpoint in suppressing mutagenic post-replicative repair in response to sublethal MMS treatment.