Differential interactions of different NS1 proteins with PSD-95 in mammalian cells. MDCK cells were transfected with either PNF-PSD-95 plasmid or empty vector PNF. At 36 h post-transfection, the cells were infected or not infected with influenza virus GD05 (H5N1) (A) or ST169 (H1N1) (B) at an MOI of 2 for 8 h. Soluble cellular lysates were immunoprecipitated with rabbit anti-PSD-95 antibody (1:100) or normal rabbit IgG. The precipitated proteins or total cell lysates (input) were resolved by SDS-PAGE and blotted with antibodies against NS1 or PSD-95. Non-specific bands are indicated.