Overexpressing a single common subunit of MLL/COMPASS complexes enhances CIITA transactivity. (A-C) Overexpression of common MLL/COMPASS subunits increases CIITA transactivity at the MHC-II promoter. HeLa cells were transfected with HLA-DRA-Luc, Renilla, pcDNA3, CIITA and (a) WDR5, (b) Ash2L or (c) RbBP5. Luciferase activity is reported as fold activation relative to that of the reporter alone. Luciferase readings were normalized to Renilla activity. Assays were performed in triplicate and values represent mean ± SEM of (n = 3) independent experiments. (d-e) Overexpression of common MLL/COMPASS subunits increases MHC-II transcript levels. HeLa cells were either left untransfected or were transfected with CIITA alone or in combination with WDR5, Ash2L or RbBP5. RNA was prepared using TRIzol reagent and cDNA was generated using gene specific antisense primers for (d) MHC-II HLA-DR and (e) GAPDH. cDNA was quantified via real-time PCR, and data are graphed as fold changes over non-transfected samples. Values represent mean ± SEM of (n = 2) independent experiments. *P < 0.05 vs control siRNA.