Localization of HPV-18 E2 at Mitochondrial Membranes Induces ROS Release and Modulates Host Cell Metabolism
Figure 3
HPV-18 E2 localizes to mitochondrial membranes.
(A) Left panel: Western-blot analyses after fractionation of extracts from HaCaT cells infected with AdGFP-ΔTAD, AdGFP-18E2, and AdGFP-6E2. Nuc: nuclear fraction, Cyt: cytoplasmic fraction, Mito: crude mitochondrial fraction after Percoll gradient. Porin, β-tubulin and cdc27 were used as markers of mitochondria, cytoplasm and nucleus respectively. Right panel: The crude mitochondrial fraction was submitted to alkali extraction. Tot: total crude mitochondria before alkali extraction. Pellet: pellet after alkali extraction containing membrane-bound proteins, Sol: supernatant after alkali extraction containing soluble proteins. (B) Immunohistochemistry showing localization of HPV-18 E2 in CIN II (left panels) and HPV-6 E2 in condyloma (right panels) using the anti-HPV-16 E2 antibody. The lower panels are high magnifications of upper panels. The first upper panel shows labeling of a HPV-negative normal cervical epithelium with the same anti-HPV-16E2 antibody performed in the same conditions as the HPV-positive samples.