The 9-1-1 checkpoint clamp physically interacts with polzeta and is partially required for spontaneous polzeta-dependent mutagenesis in Saccharomyces cerevisiae.

Journal Article (Journal Article)

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 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 proliferating cell nuclear antigen, 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.

Full Text

Duke Authors

Cited Authors

  • Sabbioneda, S; Minesinger, BK; Giannattasio, M; Plevani, P; Muzi-Falconi, M; Jinks-Robertson, S

Published Date

  • November 18, 2005

Published In

Volume / Issue

  • 280 / 46

Start / End Page

  • 38657 - 38665

PubMed ID

  • 16169844

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M507638200


  • eng

Conference Location

  • United States