Figure S4.
RNAi Knockdown of ASCC3 Isoforms and CSB and EU Labeling Assay, Related to Figure 4
(A) EU incorporation for untreated or UV-treated cell populations. Data are average EU intensity/nuclei displayed as histograms. There is a rapid reduction in EU incorporation 1 hr after UV treatment as indicated by a shift of the population to the left and corresponding increase in the percentage of cells below the low transcription threshold (indicated by the red dashed line). EU incorporation gradually recovers over the 48 hr time course. (B) RT-qPCR analysis of ASCC3 long isoform expression in cells stably expressing non-targeting (NT) shRNA and two clones stably expressing ASCC3-targeting shRNA (shASCC3) and short isoform expression 48 hr after transfection with NT and short isoform-targeting siRNA. (C) EU incorporation for shNT and shASCC3 cell lines in untreated (left panel) and UV-treated (15 J/m2, 18 hr recovery) (right panel) conditions. Data are average EU intensity/nuclei displayed as a histogram. (D) EU incorporation for UV-treated (15 J/m2, 18 hr recovery) NT and CSB-targeting siRNA transfected cells shows deficient recovery of transcription in CSB knockdown cells. Data are average EU intensity/nuclei displayed as a histogram. (E) The ratio of the proportion of low transcribing cells over high transcribing cells in untreated conditions (white bars) or 18 hr after UV (gray bars) transfected with NT or CSB siRNA. Data are mean -/+ SEM relative to UV-treated NT siRNA. t test, ∗∗∗∗p < 0.0001.