FIG. 3.

The acidic domain of IE1 is required for STAT2 binding in virus-infected cells. (A) HF cells were mock infected or infected with the wild-type, IE1(Δ421-475), or revertant viruses at an MOI of 2 IFU per cell. (Upper panel) At 24 h, total cell lysates were immunoprecipitated with anti-IE1 MAb CH443 (10 μg per 15 mg of total proteins), followed by immunoblotting with anti-STAT2 antibody. (Lower panels) The total protein levels of STAT2 and IE1 proteins in the cell extracts are also shown after immunoblotting. (B) HF cells were infected with recombinant viruses at an MOI of 1 IFU per cell. At 3 h postinfection, the cells were fixed with methanol, followed by double-label IFA with anti-IE1 and anti-STAT2 antibodies. (C) Metaphase association of wild-type or Δ421-475 mutant IE1. HF cells were infected with wild-type or IE1(Δ421-475) mutant at an MOI of 1 IFU per cell. At 72 h postinfection, the cells were fixed with methanol, followed by double-label IFA with anti-IE1 and anti-STAT2 antibodies. DAPI was used to stain DNA.