FIG 6.

Regions of 18L2 downstream of the N-terminal putative transmembrane domain become accessible in selectively permeabilized cells. HaCaT cells were infected for 24 h with HPV18 pseudovirus. Cells were fixed and permeabilized using 0.5% Triton X-100 (A and C) or 5 μg/ml digitonin (B and D) and stained using L2-specific MAbs (K4 and 28F). The ER was stained using MAb against the luminal ER marker calnexin (Calnx). Cells were fixed again and permeabilized using 0.5% Triton X-100, followed by treatment with the Click-iT reaction mixture to detect EdU. Colors are coded as indicated by the labels on the figure. Note that only the L2-specific MAb K4 and not 28F fails to detect the L2 protein adjacent to the nucleus, probably residing in the TGN (arrows), under selective permeabilization.