Fig 4.

PABP1 localization during overexpression of RVFV proteins. (A) Western blot analysis of HeLa cell lysates that were either untransfected, transfected with a plasmid encoding N, or transfected with a plasmid encoding the M segment. Untransfected cells gave no signal when probed with antibodies specific for Gn or N. Lysates of M-transfected but not N-transfected cells gave a positive signal when probed with antibody specific for Gn. The corresponding protein was between 51 and 64 kDa. Lysates of N-transfected but not M-transfected cells gave a positive signal when probed with antibody specific for N. The corresponding protein was just below 28 kDa. (B) Western blot analysis of lysates of HeLa cells that were untransfected or transfected with a plasmid encoding a FLAG-tagged partial NSm. Lysates of transfected but not untransfected cells gave a positive signal when probed with antibody specific for the FLAG epitope tag. The corresponding protein was well below the 28-kDa marker. (C) Western blot analysis of lysates of HeLa cells that were untransfected or transfected with a plasmid encoding a V5-tagged NSs. Lysates of transfected but not untransfected cells gave a positive signal when probed with antibody specific for the V5 epitope tag. The corresponding protein was between 28 and 39 kDa. (D) Immunofluorescence micrographs of HeLa cells individually expressing Gn, N, NSm, and NSs. Cells were transfected and stained for PABP1 and the specific viral protein being expressed. Arrow indicates nuclear accumulation of PABP1 in one NSs-expressing cell.