Fig. 6
The Ras-ERK1/2 signaling pathway-induced degradation of Williams-Beuren syndrome transcription factor (WSTF) is mediated by mouse double minute 2 homolog (MDM2). a-b MDM2 induces the degradation of WSTF. SNU-16 cells were co-transfected with WSTF-HA, pEGFP-K-RasG12V/T35S, of pEGFP-N1 plasmids and increasing amounts of MDM2-His plasmid (0.5, 1, and 2 g). c-d A mutation in MDM2 (MDM2-MU) that abolishes its ubiquitin ligase activity prevents WSTF degradation. The SNU-16 cells were co-transfected as indicated. e Whole cell extracts from SNU-16 cells that were transfected with pEGFP-N1 or pEGFP-K-RasG12V/T35S were analyzed using western blot. f The efficiency of the siRNA-mediated MDM2 knockdown. g The co-transfection of pEGFP-K-RasG12V/T35S and MDM2-specific siRNA restores H2A.XY142ph to normal levels