DAMAGED DNA REPAIR GENE MUTATION 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 NER 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. Accumulation of damaged DNA can lead cells to aging. However, it is not clearly known of what kinds of DNA damage contribute to aging. To this end, we analyzed the effect of DNA damage repair gene mutation on yeast lifespan. Our results show that mutations of NER and BER genes decreased yeast life span. These results suggest that increased exposure to environmental toxicants can reduce life span.