FIG. 4.

Nipah virus V-STAT complexes accumulate in the cytoplasm by a Crm1 nuclear export system. (A) Localization of V proteins. 2FTGH cells were transfected with the HA-tagged V expression vectors and treated 24 h later with LMB (10 ng/ml) for 3 (+) or left untreated (−), fixed, permeabilized, and stained as described in the legend to Fig. 3. (B) Localization of STAT proteins and Nipah virus V in the presence of LMB. Cells were processed as described above, but double staining was used to visualize effects on STAT1 and STAT2 proteins. (C) Nipah virus V blocks IFN-α signaling in the presence of LMB. 2FTGH cells were transfected with an ISRE-luciferase reporter gene, empty vector, SV5 V (SV), or Nipah virus V (NV) expression vectors. The cells were treated with 1,000 U of IFN-α per ml and/or 10 ng of LMB per ml (+) or left untreated (−) prior to lysis and luciferase assays, as in Fig. 1.