Fig. 5. Porcupine/palmitoylation regulates the activity of Wnt1 and Wnt3a in 293T cells. 293T cells were transfected with Top/FopFlash, Renilla luciferase and the indicated pHIPPY (siRNA) and pcDNA expression constructs (Kaykas and Moon, 2004). DNA concentrations were held constant within each series of experiments. The effects of mPorcD and mPorcD mutants on Wnt3a activity are shown in light blue. The effects of co-transfection of hPORC RNAi constructs with Wnt3a are shown in medium blue. The activity of Wnt3a(C77S) and Wnt1(C93S) mutants is shown in dark blue. Finally, TopFlash activity in cells co-transfected with Wnt3a(C77S) and human PORC RNAi constructs is shown in purple. `FOP' indicates samples in which FopFlash was transfected in place of TopFlash. Error bars indicate standard error. Each experiment was repeated a minimum of three times with five independent replicates each time.