Analysis of CPD ultraviolet lesion bypass in chicken DT40 cells: polymerase η and PCNA ubiquitylation play identical roles.

ABSTRACT: Translesion synthesis (TLS) provides a mechanism of copying damaged templates during DNA replication. This potentially mutagenic process may operate either at the replication fork or at post-replicative gaps. We used the example of T-T cyclobutane pyrimidine dimer (CPD) bypass to determine the influence of polymerase recruitment via PCNA ubiquitylation versus the REV1 protein on the efficiency and mutagenic outcome of TLS. Using mutant chicken DT40 cell lines we show that, on this numerically most important UV lesion, defects in polymerase η or in PCNA ubiquitylation similarly result in the long-term failure of lesion bypass with persistent strand gaps opposite the lesion, and the elevation of mutations amongst successful TLS events. Our data suggest that PCNA ubiquitylation promotes CPD b

SUBMITTER: Varga A 

PROVIDER: S-EPMC3525536 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature