Figure 3

E6 inhibits the CARM1- and PRMT1-stimulated p53-dependent transcription. (a) CARM1 and PRTM1 fail to stimulate the p53 transactivation function in the presence of E6. (b) E6 suppresses CARM1- and PRMT1-induced p21 expression. (a, b) H1299 cells were transfected with the indicated plasmids, followed by luciferase assay (a), RT–PCR and western blot analysis (b). (c) 11E6 and 16E66C/6S F47R do not interfere with p53 protein level but inhibit p21 expression. H1299 cells were transfected with the indicated plasmids for 48 h and then treated with Adr for another 6 h, followed by RT–PCR and western blot analysis. (d) Knocking down CARM1 and PRMT1 relieves the E6-mediated inhibition of endogenous p21 expression. After 24 h of siRNA transfection, U2OS cells were transfected with a plasmid encoding E6 for another 48 h. (e) Deletion of E6 from HeLa cells restores CARM1- and PRMT1-enhanced p21 expression. After 24 h of siRNA transfection, HeLa cells were transfected with plasmids encoding CARM1 and PRMT1 for 48 h, or treated with Adr for 6 h. (d, e) After transfection, quantitative RT–PCR and western blotting were performed. sc-RNA indicates si-scramble control.