Spontaneous deamination of cytosine to uracil is biased to the non-transcribed DNA strand in yeast

Copyright © 2023. Published by Elsevier B.V..

Transcription in Saccharomyces cerevisiae is associated with elevated mutation and this partially reflects enhanced damage of the corresponding DNA. Spontaneous deamination of cytosine to uracil leads to CG>TA mutations that provide a strand-specific read-out of damage in strains that lack the ability to remove uracil from DNA. Using the CAN1 forward mutation reporter, we found that C>T and G>A mutations, which reflect deamination of the non-transcribed and transcribed DNA strands, respectively, occurred at similar rates under low-transcription conditions. By contrast, the rate of C>T mutations was 3-fold higher than G>A mutations under high-transcription conditions, demonstrating biased deamination of the non-transcribed strand (NTS). The NTS is transiently single-stranded within the ∼15 bp transcription bubble, or a more extensive region of the NTS can be exposed as part of an R-loop that can form behind RNA polymerase. Neither the deletion of genes whose products restrain R-loop formation nor the over-expression of RNase H1, which degrades R-loops, reduced the biased deamination of the NTS, and no transcription-associated R-loop formation at CAN1 was detected. These results suggest that the NTS within the transcription bubble is a target for spontaneous deamination and likely other types of DNA damage.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:126

Enthalten in:

DNA repair - 126(2023) vom: 15. Juni, Seite 103489

Sprache:

Englisch

Beteiligte Personen:

Williams, Jonathan D [VerfasserIn]
Zhu, Demi [VerfasserIn]
García-Rubio, María [VerfasserIn]
Shaltz, Samantha [VerfasserIn]
Aguilera, Andrés [VerfasserIn]
Jinks-Robertson, Sue [VerfasserIn]

Links:

Volltext

Themen:

56HH86ZVCT
8J337D1HZY
9007-49-2
Cytosine
DNA
Deamination
Journal Article
Mutagenesis
R-loops
RNA polymerase
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Transcription
Transcription bubble
Uracil

Anmerkungen:

Date Completed 26.04.2023

Date Revised 13.09.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.dnarep.2023.103489

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM355236893