NF45 interacts with viral proteins VP1, VP2, and VP3. (A) Lysates of the cytoplasmic fractions of nontransfected DF-1 cells (DF1), DF-1 cells transfected with pcDNA3-ckNF45FLAG (DF1/NF45), nontransfected but IBDV-infected DF-1 cells (DF1/D78), and pcDNA3-ckNF45-FLAG-transfected and IBDV-infected Df1 cells (Df1/NF45/D78) were analyzed either directly in a Western blot assay (WB) or were immunoprecipitated (IP) using the anti-FLAG MAb followed by Western blot analysis of the IP products. (B and C) Lysates of the cytoplasmic fractions of noninfected DF-1 cells (DF1) and IBDV-infected DF-1 cells (DF1/D78) were either directly used for WB or for IP using the VP2-specific MAb R63 (B) or the VP3-specific MAb IBDV2 (C) followed by Western blot analysis. Western blots shown in all three panels were performed using rabbit anti-ckNF45-His serum or rabbit anti-VP1, -VP2, or -VP3 serum. The detected proteins are named and marked by arrows. The molecular masses (in kilodaltons) of protein markers are indicated to the left of each gel.