Effect of TSA on JCV transcription by reporter constructs containing mutation in the KB element. A. TC620 cells were transfected with JCV early reporter constructs containing mutation (m1 and m2) in the NCCR KB element and wild-type JCV early reporter, treated with TSA as indicated, harvested and assayed for luciferase activity. NEG CON – plasmid vector negative control. Activities were normalized to untreated wild-type control (lane 10). The bar represents one standard deviation. B. TC620 cells were transfected with pBLCAT2 or heterologous promoters containing either mutant or wild-type JCV KB elements, which we have previously described , treated with TSA as indicated, harvested and assayed for CAT activity. Activities are given in arbitrary units. The bar represents one standard deviation.