Fig. 5. Enhanced TGFβ signaling in Dpr2^–/– keratinocytes. (A) Reporter gene assay. Dpr2^–/– and wild-type (WT) keratinocytes were transfected with (CAGA)₁₂-luciferase or cotransfected with constitutively active forms of ALK5 (caALK5) or mouse Dpr2 (mDpr2). Next day, the cells were treated with or without TGFβ1 (Tβ1, 5 ng/ml) for another 20 hours. Results are relative luciferase activity of transfected cells compared with the Renilla control. All values are expressed as mean ± s.d., n=3, ^*P<0.05, ^**P<0.01. (B,C) Western blot analyses of protein extracts from Dpr2^–/– and wild-type keratinocytes for ALK5 (B) and phosphorylated Smad2 (Smad2-P) (C). Cells treated with or without TGFβ1 (Tβ1) for 48 hours. β-actin or total Smad2 served as loading controls. Bar charts show densitometry results. All values are mean ± s.d., n=3; ^**P<0.01.