FIG 1.

E2 K111R failed to recruit Topo1 to the replication origin. C33A cells were transfected with FLAG-E1, FLAG-E2, and HPV31 Ori. ChIP assays were conducted for E2 and E1 with anti-FLAG antibodies, and endogenous Topo1 with anti-Topo1 antibodies using primers at the HPV31 LCR. Values were normalized to inputs. (A) Equivalent amounts of E2 proteins were detected at the origin. (B) WT and K111Q show significantly higher Topo1 recruitment compared to that of the control transfected with only E1. (C) E2 recruitment of Topo1 in the absence of E1 shows K111R is not significantly different from the control samples, and K111Q is increased compared to the wild type. (D) ChIP for replication initiation factors at the LCR and E4 ORF in synchronized CIN612 cells relative to IgG antibody control. *, p < 0.05; **, p < 0.005; ***, p < 0.0001 by one-way analysis of variance (ANOVA).