The rabbit polyclonal antibodies recognizing the C terminus of IBV E and the N-terminal head of golgin-160 have been previously described (42 (link), 43 (link)). The antibody generated against the C terminus of IBV S (anti-IBV SCT) has also been previously described (26 (link)). The mouse monoclonal antibody recognizing IBV S1 was a gift from Ellen Collisson (25 (link)). The mouse monoclonal antibody recognizing the N terminus of influenza A virus M2 has been previously described and was a generous gift from Andrew Pekosz (44 (link)). The mouse anti-GFP antibody was obtained from Roche (Mannheim, Germany). The rabbit anti-GFP antibody was obtained from Thermo Fisher Scientific (Rockford, IL). Alexa Fluor 488-conjugated anti-rabbit IgG, Alexa Fluor 488-conjugated anti-mouse IgG, Alexa Fluor 568-conjugated anti-rabbit IgG, and Alexa Fluor 568-conjugated anti-mouse IgG were obtained from Invitrogen/Molecular Probes (Eugene, OR).