FIGURE 4.

Overexpression or knockdown of FKBP25 does not affect steady-state levels of pre-rRNA intermediates. (A) Northern blot of RNA extracted from untransfected HEK293 cells or HEK293 cells transfected with control siRNA or FKBP25-targeting siRNA. Blots were probed for ITS1 (left) or ITS2 (right). Extracts were Western blotted for FKBP25 to verify knockdown. (B) Northern blot of RNA extracted from HEK293 from control and cells overexpressing FLAG-FKBP25. Blots were probed for ITS1 (left) or ITS2 (right). (C) Northern blot of HEK293 cells treated with vehicle or rapamycin probed for ITS1 (left) or ITS2 (right). (D) Schematic of rRNA processing steps. (*) Nonspecific probe binding.