Abstract
8-Oxo-guanine(8-oxo-G), an oxidized form of guanine by attack of active oxygen species are one of the major sources for spontaneous mutations in nucleic acids. To prevent the mutagenic consequences of 8-oxo-G, organisms have developed cellular defense mechanisms by the sanitation of nucleotide pools and base excision repair pathway. We have reported previously that AtNUDX1 protein hydrolyzes 8-oxo-(d)GTP and completely suppresses increased frequency of spontaneous mutations in the E. coli mutT - strain. In this study, we studied the physiological function of AtNUDX1. AtNUDX1 suppressed transcriptional errors caused by 8-oxo-GTP in E. coli mutT - strain. The level of 8-oxo-G in AtNUDX1-knockout plants was significantly increased compared with that in the wild-type plants under normal and stressful conditions, indicating that AtNUDX1 play an important role in the sanitization of nucleotide pools. We are progressing toward to analyze the localizations of AtNUDX1 and the enzymes involved in the base excision repair pathway.
