Knockdown of PRMT1 affects AE9a-driven transcription activation. (A) Knockdown of PRMT1 by siRNA. Knockdown efficiency of endogenous PRMT1 was examined by Western blot analysis. In lanes 1 through 4, WT K562 cells or AE9a-expressing K562 cells were transfected with either control siRNA or siPRMT1. These cells were used in microarray analysis. In lanes 5 and 6, WT K562 cells were cotransfected with pGLX2-MT2A-Luc, p3xFLAG-AE9a, and either control siRNA or siPRMT1. These cells were used in luciferase reporter assay. α-tubulin is used as a loading control. (B) Bar chart represents relative expression level in log₂ scale of selected genes in microarray analysis. Results from AE9a-Control siRNA are normalized to K562-Control siRNA cells. Results from AE9a-siPRMT1 are normalized to K562-siPRMT1 cells. (C) Bar chart represents relative expression level in log₂ scale of selected genes by RT-qPCR to validate results from microarray analysis. GAPDH is used as an internal control. Results from AE9a-Control siRNA are normalized to K562-Control siRNA cells. Results from AE9a-siPRMT1 are normalized to K562-siPRMT1 cells. Error bars represent SDs of 3 independent experiments. (D) PRMT1 is important for AE9a-dependent transcription of MT2A. WT K562 cells were cotransfected with pGLX2-MT2A-Luc, p3xFLAG-AE9a, and either control siRNA or siPRMT1. Error bars represent SDs of 3 independent experiments.