Recovery of RNA polymerase II synthesis following DNA damage in mutants of Saccharomyces cerevisiae defective in nucleotide excision repair.

We have measured the kinetics of the recovery of mRNA synthesis in the inducible GAL10 and RNR3 genes after exposure of yeast cells to ultraviolet (UV) radiation. Such recovery is abolished in mutant strains defective in nucleotide excision repair (NER) of DNA, including a rad23 mutant. Mutants defective in the RAD7 or RAD16 genes, which are required for the repair of the non-transcribed strand but not the transcribed strand of transcriptionally active genes, show slightly faster recovery of RNA synthesis than wild-type strains. A strain deleted of the RAD26 gene, which is known to be required for strand-specific NER in yeast, manifested delayed recovery of mRNA synthesis, whereas a rad28 mutant, which does not show defective strand-specific repair, showed normal kinetics of recovery. Measurement of the recovery of expression of selected individual yeast genes by Northern analysis following exposure of cells to UV radiation apparently correlates directly with the capacity of cells for strand-specific NER.