Fig. 8

Galectin-3 interacts with the PA subunit of the RdRp. a The association of galectin-3 with viral proteins. 293T cells were cotransfected with expression vectors encoding Flag-tagged galectin-3 and the indicated HA-tagged IAV proteins. The cell lysates were prepared for immunoprecipitation with anti-HA agarose. The cell lysates (input) and the immunoprecipitates were subjected to immunoblot analysis with anti-HA or anti-Flag antibody. b Colocalization of galectin-3 with the PA subunit in IAV-infected cells. A549 cells were transfected with pCR3.1-Gal-3-Flag for 48 h and then infected with IAV at an MOI of 5 for 8 h. Cells were then fixed and permeabilized for immunofluorescence staining with anti-PA (red) and anti-Flag (green) antibodies. Nuclei were stained with DAPI. Representative images are shown (original magnification ×900, scale bar = 5 μm). c Association of PA subunit with PB1 subunit in the presence of galectin-3. 293T cells were cotransfected with expression vectors encoding the Flag-tagged galectin-3, HA-tagged PB1, and Myc-tagged PA. Whole cell lysates without immunoprecipitation (5% input) were estimated for the expression levels of PA, PB1, and galectin-3 (left). Cell lysates were used for immunoprecipitation with the anti-HA agarose. Cell lysates (input) and immunoprecipitates were subjected to immunoblot analysis with anti-HA, anti-PA, and anti-Flag antibodies. IP: immunoprecipitation; WB: western blotting