Transcription profiling of yeast TOP1 null strain bearing plasmids that express wild-type yeast Top1p or an inactive Y727F mutant enzyme and treated with camptothecin

To establish the effect of CPT in the regulation of global transcription in S. cerevisiae, we have used a yeast TOP1 null strain, JEL1Δtop1, bearing a low-copy number plasmid that expresses, under the control of the yeast TOP1 promoter, either a wild-type (wt) yeast Top1p (pCC10) or an inactive Y727F mutant enzyme (pAR7).We determined global transcript levels upon CPT treatments of JEL1Δtop1 cells expressing either a yeast wt or Y727F mutant Top1p.