Accumulation of a basic sites is highly mutagenic and leads to decreased lifespan in yeast

초록

Environmental DNA damaging agents such as ultraviolet (UV) light and chemical pollutants, and endogeneous factors such as reactive oxygen species constantly damage cellular DNA. Such damaged DNA is repaired by nucleotide excision repair (NER) and base excision repair (BER). Thus, mutations in NERR and BER related genes causes damaged DNA accumulation which has been referred to be correlated with aging. We found, in our previous study, that mutations in BER genes drastically increase spontaneous mutagenesis, MMS sensitivity and transcription blockage in yeast. Additional mutations of NER genes enhanced these effects. In this study, we compared lifespan of BER gene mutated yeast to that of normal cells in order to understand the connection between the accumulation of damaged DNA and aging. Our results show that mutations of NER and BER genes decreased yeast life span.