DNA damage can lead to mutations during replication. The damage-induced mutagenesis pathway is an important mechanism that fixes DNA lesions into mutations. DNA polymerase ζ (Polζ), formed by Rev3 and Rev7 protein complex, and Rev1 are components of the damage-induced mutagenesis pathway. Since mutagenesis is an important factor during the initiation and progression of human cancer, we postulate that this mutagenesis pathway may provide an inhibiting target for cancer prevention and therapy. In this study, we tested if UV-induced mutagenesis can be altered by molecular modulation of Rev3 enzyme levels using the yeast Saccharomyces cerevisiae as a eukaryotic model system. Reducing the REV3 expression in yeast cells through molecular techniques was employed to mimic Polζ inhibition. Lower levels of Polζ significantly decreased UV-induced mutation frequency, thus achieving inhibition of mutagenesis. In contrast, elevating the Polζ level by enhanced expression of both REV3 and REV7 genes led to a ~3-fold increase in UV-induced mutagenesis as determined by the arg4-17 mutation reversion assays. In vivo, UV lesion bypass by Polζ requires the Rev1 protein. Even overexpression of Polζ could not alleviate the defective UV mutagenesis in the rev1 mutant cells. These observations provide evidence that the mutagenesis pathway could be used as a target for inhibiting damage-induced mutations. Copyright (C) 2000 Elsevier Science B.V.
|Number of pages
|Mutation Research - DNA Repair
|Published - Oct 16 2000
Bibliographical noteFunding Information:
We thank Christopher Lawrence for providing us with the yeast strains CL1265-7C, AMY32, and the rev7 deletion plasmid pYPG102, and R. Daniel Gietz for plasmids Yeplac181 and Yeplac195. We thank Elena Braithwaite for critical review of this manuscript. These studies were supported by a THRI grant from the Tobacco and Health Research Institute of the University of Kentucky and a New Investigator Award in Toxicology from Burroughs Wellcome Fund. D.K. Rajpal is a recipient of the Kentucky Research Challenge Trust Fund Fellowship and Commonwealth Research Award.
- DNA polymerase ζ
- Deoxycytidyl transferase
- UV damage
ASJC Scopus subject areas
- Molecular Biology