SUMOylation of Oct4 enhances Nanog expression.

<p>(A) Oct4 is modified by Sumo1 at Lysine 118. Wild-type Oct4 or the SUMO receptor site mutant Oct4 K118R was expressed in combination with HA-Sumo1 and HA-Ubc9 in F9 EC cells. (B) qPCR analysis of <i>Nanog</i> mRNA in response to various levels of SUMOylated Oct4. The levels of the transcripts were normalized against control empty vector transfection. (C) Western blot analysis of Nanog in F9 EC cells under a varying SUMOylation status of Oct4. (D) SUMOylation of Oct4 enhances the <i>Nanog</i> proximal promoter transcription. Transcriptional activities of the <i>Nanog</i> promoter (−230 to +50 bp relative to the transcription start site) in response to various levels of SUMOylated Oct4 were determined by dual-luciferase reporter assays. qPCR data were normalized to <i>GAPDH.</i> Data are presented as the mean +/− SD and are derived from three independent experiments. *, p<0.05; **, p<0.01; WB: western blot.