Colocalization of Gβ subunits and Tax-1. (A-B) HeLa cells were transfected with Flag- Gβ1, Flag- Gβ2, or HTLV-1 Tax–expressing constructs. Twenty-four hours after transfection, cells were fixed, permeabilized, and stained with anti-Flag or anti–Tax-1 antibodies and Alexa 546 or fluorescein-conjugated secondary antibodies. Cells then were labeled with TOPRO-3 and analyzed under a confocal microscope. (C) HeLa cells were cotransfected with Flag-Gβ1+ HTLV-1 Tax– and Flag-Gβ2+ HTLV-1 Tax–expressing constructs. Twenty-four hours after transfection, cells were fixed, permeabilized, and stained with anti-Flag and anti–Tax-1 antibodies followed by Alexa 546– and fluorescein-conjugated secondary antibodies. Cells then were labeled with TOPRO-3 and analyzed under a confocal microscope.