Klf5 acetylation, stimulated by TGF-β signaling, facilitates pluripotency maintenance in mouse ESCs.

<p>(A) TGF-β signaling promotes Klf5 acetylation. V6.5 ESCs were treated with 10 μg/ml TGF-β or 5 μM SB525334 (SB) for 48 hours, and then harvested for subsequent Western blot experiments. The nonspecific band in the anti-Klf5 blot is marked by an asterisk. The expression levels of Ac-Klf5 were quantified and normalized to Klf5. Averages and standard deviations of Ac-Klf5 expression from three experiments are shown. (B) Overexpression of KQ Klf5 mutant antagonizes the suppression effect of TGF-β signaling on Sox2 protein expression. Empty pCAGIPuro, Flag-tagged WT and KQ Klf5 overexpression plasmids were transfected into V6.5 ESCs. Cells were cultured in mouse ESC medium with or without 5 μM SB525334 for 2 days, and then harvested for subsequent Western blot experiments. The nonspecific band in the anti-Klf5 blot is marked by an asterisk. (C) The effect of WT and KQ Klf5 overexpression on the repression of pluripotency gene transcription by TGF-β signaling. Cells were treated as described in (B), and harvested for RNA purification and quantitative RT-PCR analysis. Averages and standard deviations from three independent experiments were plotted.