Figure 3. Sirt1 interacts with 9G8 directly. (A) Myc-tagged SIRT1 and HA-tagged 9G8 were co-expressed in HEK-293T cells. After 48 h transfection, cell lysate was incubated with anti-HA antibody coupled onto protein G beads. The proteins bound on beads were analyzed by western blot developed with anti-HA and anti-Myc. (B) Sirt1 tagged with Myc and 9G8 tagged with HA were co-overexpressed in Hela cells. After 48 h transfection, the cells were fixed and immunostained with anti-HA or anti-Myc and followed by TRITC-anti-rabbit IgG or FITC-anti-mouse IgG. Hoechst was used for nuclear staining.