A newly identified interaction between IVa2 and pVIII proteins during porcine adenovirus type 3 infection

The adenovirus IVa2 is an intermediate viral gene product that appears to perform multiple essential roles in viral infection. Using IVa2 as bait in the yeast two-hybrid system, we screened selected open reading frames (ORFs) of porcine adenovirus (PAdV)-3 for potential interaction with IVa2. Interestingly, pVIII showed specific interaction with IVa2. The yeast two-hybrid findings were validated by GST pull-down assays, in vitro binding studies employing cell-free coupled transcription-translation products and in vitro co-immunoprecipitations using protein-specific antibodies. Finally, we demonstrated that IVa2 specifically interacts with pVIII during PAdV-3 infection.