FIG. 4.

Mutations within NS4B's NBM are not associated with obvious changes in protein expression level or intracellular distribution pattern. Huh-7 cells plated on coverslips were transfected with plasmids encoding wild-type NS4B-GFP (WT) or NS4B-GFP with one of the following NBM mutations: Gly129Val (GV), Ile131Asn (IN), Lys135Ser (KS), or Lys135Arg (KR). Eighteen hours posttransfection the cells were fixed and imaged by a fluorescence microscope. Note that all of these proteins display the same reticular membrane localization pattern with distinct foci located in the cytoplasm that is characteristic of wild-type NS4B.