Formaldehyde-induced mutagenesis in Saccharomyces cerevisiae: molecular properties and the roles of repair and bypass systems.

Published

Journal Article

Although DNA-protein cross-links (DPCs) pose a significant threat to genome stability, they remain a poorly understood class of DNA lesions. To define genetic impacts of DPCs on eukaryotic cells in molecular terms, we used a sensitive Saccharomyces cerevisiae frameshift-detection assay to analyze mutagenesis by formaldehyde (HCHO), and its response to nucleotide excision repair (NER) and translesion DNA synthesis (TLS). Brief exposure to HCHO was mutagenic for NER-defective rad14 strains but not for a corresponding RAD14 strain, nor for a rad14 strain lacking both Polζ and Polη TLS polymerases. This confirmed that HCHO-generated DNA lesions can trigger error-prone TLS and are substrates for the NER pathway. Sequencing revealed that HCHO-induced single-base-pair insertions occurred primarily at one hotspot; most of these insertions were also complex, changing an additional base-pair nearby. Most of the HCHO-induced mutations required both Polζ and Polη, providing a striking example of cooperativity between these two TLS polymerases during bypass of a DNA lesion formed in vivo. The similar molecular properties of HCHO-induced and spontaneous complex +1 insertions detected by this system suggest that DPCs which form in vivo during normal metabolism may contribute characteristic events to the spectra of spontaneous mutations in NER-deficient cells.

Full Text

Duke Authors

Cited Authors

  • Grogan, D; Jinks-Robertson, S

Published Date

  • March 1, 2012

Published In

Volume / Issue

  • 731 / 1-2

Start / End Page

  • 92 - 98

PubMed ID

  • 22197481

Pubmed Central ID

  • 22197481

International Standard Serial Number (ISSN)

  • 0027-5107

Digital Object Identifier (DOI)

  • 10.1016/j.mrfmmm.2011.12.004

Language

  • eng

Conference Location

  • Netherlands