REGULATED EXPRESSION OF THE SACCHAROMYCES-CEREVISIAE DNA-REPAIR GENE RAD7 IN RESPONSE TO DNA DAMAGE AND DURING SPORULATION

The RAD7 gene of Saccharomyces cerevisiae affects the proficiency of excision repair of DNA damaged by UV light. Here, we report our studies on the regulationof the RAD7 gene in response to UV irradiation and during sporulation. RAD7 transcript levels increased 6-fold within 40 min of exposure of cells to 37 J/m2 ofUV light. Higher UV doses also elicited rapid increases in the level of RAD7 mRNA. RAD7 mRNA levels increased in sporulating MATa/MAT α diploid cells, but not in the asporogenous MATa/MAT α strain exposed to sporulation conditions. The increase in RAD7 mRUA level in MATa/MATα cells was 15-fold after 6 h and 9-fold after 7 h in sporulation medium; thereafter, RAD7 mRNA levels declined. Periodic transcription of RAD7 during sporulation suggests a role for RAD7 in this process. © 1990 Oxford University Press.