PP1γlevels are downregulated in HPV16 positive cells by HPV E6/E7 oncogenes. (A) HPV-16 positive CaSki and SiHa cells were transfected with siRNAE6/E7 or siLuc as control. Total cell extracts were then made after 72 hours, and hScrib, PP1γ, p53 and Actin were detected by western blotting. (B) 293 cells were transfected with 4, 8, 10 μg of HPV-16 E6 expression plasmid, and hScrib and PP1γ were analysed by Western blotting. The middle panel shows the LacZ transfection efficiency and loading control. (C) HaCaT cells were transfected with 5 μg of HPV-16 E6 expression plasmid, and hScrib and PP1γ were analysed by Western blotting. Tubulin was detected as control. (D) CaSki, SiHa, HeLa, C33A and HaCaT cells were incubated in the presence of either 10 μM MG132 or solvent before harvesting and analysed by western blotting. Actin was used as a loading control.