FIG. 1.

(A) Cell-cell fusion induced by coexpressed HN and F proteins. Subconfluent HeLa cell monolayers in six-well culture plates were transfected with the recombinant plasmid encoding the F protein of SV41 or PIV5 (WR) together with the recombinant plasmid encoding the SV41 HN protein, PIV5 (W3A) HN protein, or the chimeric HN protein, CH5-41. After 24 h of incubation, the cells were fixed with 4% paraformaldehyde and stained with Giemsa solution. Scale bar, 100 μm. (B) Schematic diagram of CH5-41. TM, transmembrane domain.