Sabbioneda S, et al. (2005) The 9-1-1 checkpoint clamp physically interacts with polzeta and is partially required for spontaneous polzeta-dependent mutagenesis in Saccharomyces cerevisiae. J Biol Chem 280(46):38657-65
Abstract: The use of translesion synthesis (TLS) polymerases to bypass DNA lesions during replication constitutes an important mechanism to restart blocked/stalled DNA replication forks. Because TLS polymerases generally have low fidelity on undamaged DNA, the cell must regulate the interaction of TLS polymerases with damaged versus undamaged DNA in order to maintain genome integrity. The Saccharomyces cerevisiae checkpoint proteins Ddc1, Rad17 and Mec3 form a clamp-like structure (the 9-1-1 clamp) that has physical similarity to the homotrimeric sliding clamp PCNA, which interacts with and promotes the processivity of the replicative DNA polymerases. In this work, we demonstrate both an in vivo and in vitro physical interaction between the Mec3 and Ddc1 subunits of the 9-1-1 clamp and the Rev7 subunit of the Polzeta TLS polymerase. In addition, we demonstrate that loss of Mec3, Ddc1 or Rad17 results in a decrease in Polzeta-dependent spontaneous mutagenesis. These results suggest that, in addition to its checkpoint signaling role, the 9-1-1 clamp may physically regulate Polzeta-dependent mutagenesis by controlling the access of Polzeta to damaged DNA.
|Status: Published||Type: Journal Article||PubMed ID: 16169844|
Topics addressed in this paper
Number of different genes curated to this paper: 6
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