Figure 3. Pol II transcription interferes with RNA Pol III activity.

(A) Overlays of input-subtracted RPC62 and RPB3 ChlP-seq coverage and normalized nascent RNA in RPBl-expressing (Ctl, blue) or RPBl-depleted (DA, red) clone #7 and #19 cells at a MIR locus that is transcribed by Pol III in the anti-sense direction from the Pol ll-transcribed POLR3E gene. The nascent RNA coverage tracks of DRB-treated (yellow) and mock-treated (green) cells from Werner and Ruthenburg (2015) are also shown. The loss of elongating Pol II at this locus is correlated with an increase in Pol III occupancy and transcription of the MIR element in both DA-treated cells and DRB-treated cells. (B) tRNA genes affected >1.5-fold at the nascent RNA level with a FDR<0.05 in DRB-treated HEK293 cells (data ranked by Log₂ fold change). tRNA genes affected significantly in DA-treated clones #7 and #19 cells are indicated by purple bars. Black rectangles identify the 3 model tRNA genes used in following experiments. (C) Profiles of nascent RNA, RPB3 and RPC62 enrichment scores at tRNA genes upregulated in both DA-treated and DRB-treated cells (1), upregulated in DRB only (2) or downregulated in DRB only (3) as defined in (B).