Fig. 4.

MAB21L4 up-regulates involucrin expression. (A) Up-regulation of involucrin protein induced by TGF-β was abrogated by MAB21L4 siRNA. HaCaT cells were transfected with two different MAB21L4 siRNAs and stimulated with TGF-β for 24 h. The experiment was repeated with the similar results, and the representative data are shown. (B) The effect of MAB21L4 siRNA on the expression of MAB21L4 mRNA in HaCaT cells. HaCaT cells were transfected with MAB21L4 siRNAs and stimulated with TGF-β for 24 h. Data were obtained from two biological replicates. (C) Smad3 and Smad2 binding regions at the promoter of the IVL locus. Significant binding regions are represented as in Fig. 2C. The region (−2812 to +81 from the TSS) used in the promoter-reporter analysis shown in (D) is also indicated in the bottom panel. (D) MAB21L4 siRNAs down-regulated TGF-β-induced transcriptional activity of the IVL promoter. HaCaT cells were transfected with luciferase reporter plasmids and siRNA as indicated. Cells were then stimulated with TGF-β or left untreated. Data were obtained from four biological replicates.