Mutagenic properties of oxidized GTP and ATP in in vitro transcription-reverse transcription

Oxidation of RNA precursors may disturb genetic information by mispair formations. In this study, effects of oxidized ribonucleoside triphosphates on in vitro transcription catalyzed by T7 RNA polymerase were examined. 8-Hydroxyguanosine 5'-triphosphate (8-OH-GTP) and 2-hydroxyadenosine 5'-triphosphate (2-OH-ATP) reduced amount of RNA. In addition, mRNA was converted to cDNA by Reverse Transcriptase, and the cDNA was then amplified by PCR. The PCR product was subsequently cloned into plasmid DNA and sequence of DNA was analyzed for each Bacterial colony. The two oxidized ribonucleotides induced mutations in cDNA, suggesting disturbance of genetic information during transcription and/or reverse transcription. 8-OH-GTP induced T-->G plus T-->C mutations and 2-OH-ATP caused T-->C mutations. These results indicate that formation of these oxidized RNA precursors in cells affects transcription quantitatively and qualitatively. In addition, they are potential Antiviral drugs that cause mutations in genomic RNA.