Validation of HR-specific interactions.

(A) HeLa cells were transfected by pTK6E2BS-Luc reporter and HPV16 or HPV18 E2 expression plasmids. Where indicated, GTF2B was added. Fold activation is given relative to TK6E2BS-Luc in the absence of E2. (B) HeLa cells were transfected with a pool of four siRNA targeting GTF2B or control siRNA (Scramble). 48 h post silencing, pTK6E2BS reporter plasmid was transfected along with E2 expression plasmids. Results are given as a fold activation relative to TK6E2BS basal activity in the presence of the same siRNA. Experiments were performed in triplicate with each bar representing the mean ± SD. The stars (***) indicate a statistical significant difference between fold activation by 16E2 with a scramble siRNA or a GTF2B-directed siRNA directed (p-value<0,001) (C) HaCaT cells were co-transfected by GFP-E2 proteins from HPV16 or HPV18 and mCherry-VPS39. 24 h later, cells were fixed in 4% paraformaldehyde, stained with DAPI and subjected to fluorescence microscopy.