Yeast SPT4 in the modulationof UV-induced mutagenesis

초록

Ultra violet (UV) light exposed cells suffer from damages of the cell component including DNA, increased mutation rate and accelerate aging. UV-damaged DNA is exclusively repaired by nucleotide excision repair. Especially, damaged DNA repair is a pivotal factor that determines cell fate. Persistent DNA damage can cause cell cycle arrest, mutagenesis, and cell death. When DNA damage is successfully repaired, cells resume regular cell cycle. On the other hand, error-prone repair can causes mutations and cancerous cell formation. In order to insure sufficient time for damaged DNA repair, DNA replication and transcription are stalled. Previously, we reported that some of nucleotide excision repair related genes serve as transcription elongation factors, and the defect of the gene causes drastically increased spontaneous and MMS-induced mutagenesis. In this study, we characterized SPT4, a gene encoding NER-independent transcription elongation factor. We found that SPT4 expression is increased when a NER-related transcription elongation factor is defective. We discuss the possibility of SPT4 function in increased UV-induced mutagenesis of NER defective cells.