Multiprobe RNase protection assay analysis of mRNA levels for the Escherichia coli oxidative DNA glycosylase genes under conditions of oxidative stress.
Escherichia coli formamidopyrimidine DNA glycosylase (Fpg), MutY DNA glycosylase, endonuclease VIII, and endonuclease III are oxidative base excision repair DNA glycosylases that remove oxidized bases from DNA, or an incorrect base paired with an oxidized base in the case of MutY. Since genes encoding other base excision repair proteins have been shown to be part of adaptive responses in E. coli, we wanted to determine whether the oxidative DNA glycosylase genes are induced in response to conditions that cause the type of damage their encoded proteins remove. The genes fpg, mutY, nei, and nth encode Fpg, MutY, endonuclease VIII, and endonuclease III, respectively. Multiprobe RNase protection assays were used to examine the transcript levels of these genes under conditions that induce the SoxRS, OxyR, and SOS regulons after a shift from anaerobic to aerobic growth and at different stages along the growth curve. Transcript levels for all four genes decreased as cells progressed from log-phase growth to stationary phase and increased after cells were shifted from anaerobic to aerobic growth. None of the genes were induced by hydrogen peroxide, paraquat, X rays, or conditions that induce the SOS response.
Gifford
C M
CM
Department of Microbiology and Molecular Genetics, The Markey Center for Molecular Genetics, The University of Vermont, Burlington, Vermont 05405-0068, USA.
Blaisdell
J O
JO
Wallace
S S
SS
D000332:Aerobiosis; D000693:Anaerobiosis; D045647:DNA Glycosylases; D004260:DNA Repair; D043382:DNA-Formamidopyrimidine Glycosylase; D043224:Deoxyribonuclease (Pyrimidine Dimer); D004706:Endodeoxyribonucleases / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D009699:N-Glycosyl Hydrolases / Q000235:genetics*; D018384:Oxidative Stress; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012260:Ribonucleases; D014158:Transcription, Genetic
D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D004706:Endodeoxyribonucleases; D012260:Ribonucleases; D043224:Deoxyribonuclease (Pyrimidine Dimer); C106403:NTH protein, E coli; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; C061738:mutY adenine glycosylase; D043382:DNA-Formamidopyrimidine Glycosylase; C468610:DNA-formamidopyrimidine glycosylase, E coli