A. Huh7 cells were transfected with DNA constructs expressing various Rab proteins with an N-terminal CFP (Rab1, 2, 6 &7) or GFP (Rab5) fusion. At 24 h post-transfection, the cells were processed and pictures were taken with a confocal microscope (i-v). Also shown are controls including CFP-expressing Huh7 (vi) as well as Huh7 (vii) and C5B (viii) cells stained for NS4B expression. Notice the diffuse and nuclear fluorescence of CFP alone and the absence of NS4B staining in Huh7 cells. B. C5B cells were transfected with DNA constructs expressing CFP-Rab1 (i-iv; a), CFP-Rab2 (iv-vi; b), GFP-Rab5 (vii-ix; c), CFP-Rab6 (x-xii; d) and CFP-Rab7 (xiii-xv; e). At 24 h post-transfection, the cells were stained with NS4B-specific antibody and samples were examined via confocal microscopy. Magnified areas are indicated by rectangles. Note that the CFP-expressing Rab proteins were pseudo-colored green. C. Quantitation results are from at least five Rab- and NS4B-expressing cells. Pearson colocalization results are significant when the coefficient (PC) is at least 0.5. Notice the moderate to strong merging of Rab5 or 7 with NS4B foci. There is weak colocalization of NS4B with Rab1, 2 and 6. Bars = 10 μm.