Fig. 2.

The TM domain, particularly A10N, A14N and A18N, of Vpu is required for the efficient downregulation of cell surface CD155. HeLa cells were transfected with either Vpu-IRES-GFP or mutants thereof. 24 h post transfection, cells were harvested and either stained for surface CD155 (A) or intracellular CD155 (B) using a CD155 specific antibody. Subsequently, cells were analyzed by flow cytometry. Summary of relative CD155 surface (A) and intracellular (B) expression from 3 independent experiments is given below. Mock indicates non-infected and unstained control cells. Values from three independent experiments were plotted and assessed for statistical significance by using the GrapPad Prism V5.0 software package (***; p≤0.0005, 1 way- ANOVA with Dunnett’s test). In addition, cells were lysed and analyzed by Western blot using anti-β-actin, anti-GFP and anti-Vpu antibodies (C).