Fig. 5. Rescue of histone H3 phosphorylation by transfection of MSK2. MSK1/2 double-knockout cells were transfected with a construct encoding GFP-tagged MSK2. The cells were serum starved and then left unstimulated (A and C) or treated with 10 µg/ml anisomycin for 30 min (B and D). Cells were then fixed, and the expression of MSK2 and phosphorylation of histone H3 on Ser10 (A and B) or Ser28 (C and D) was determined by immunofluorescence. Histone H3 phosphorylation is shown in red, GFP–MSK2 in green and DNA (DAPI) in blue.