Figure 1.

The WD/E motifs in A36 are required for efficient virus transport to the cell periphery. (A) Schematic representation of A36 highlighting its TM domain and positions of the WE and WD motifs at residues 64–65 and 97–98, respectively. (B) Representative immunofluorescence images showing actin tail formation (red) by the indicated A36–YFP WE/WD mutant viruses (green) at 8 h post-infection. Scale bar=10 μm. The graph shows quantification of the number of actin tails per cell for the indicated viruses. A P-value of <0.05 and <0.001 is indicated with ^* and ^***, respectively, while error bars represent standard error of the mean from 50 cells in three independent experiments. (C) Representative immunofluorescence images showing the spread of the indicated recombinant A36–YdF–YFP viruses (green) from their perinuclear site of assembly to the cell periphery at 8 h post-infection compared with the ΔA36R virus. Scale bar=10 μm. The different viruses are co-labelled with anti-A27 (red), which detects both IMV and IEV, the latter of which appear yellow as they contain both A27 and A36–YdF–YFP. The graph shows quantification of viral spread to the cell periphery at 8 h post-infection based upon fluorescence intensity measurements of extracellular B5, an IEV-specific protein, detected with a monoclonal antibody in non-permeabilized cells. A P-value of <0.05 and <0.001 is indicated with ^* and ^***, respectively. Error bars represent standard error of the mean from 50 cells in three independent experiments.