Distinct complex formation among MBD2a, RHA, and HDAC1. (A) Cells of the HEK-293 cell line were transiently transfected to produce HA-RHA and/or FLAG-MBD2a and FLAG-MBD2b. The cell lysates were immunoprecipitated with anti-HA antibody or anti-FLAG antibody and immunoblotted with anti-HDAC1 (upper panel), anti-HA antibody (middle panel), or anti-FLAG antibody (lower panel). The asterisk indicates immunoprecipitated IgG heavy chain. (B) HEK-293 cells were transfected with FLAG-MBD2a, and each nuclear extract was subsequently incubated with increasing mounts of GST-RHA1. The amount of GST-recruited MBD2a was visualized by Western blotting by using anti-FLAG antibodies. The MBD2a present in the supernatant of GST pull-down was immunoprecipitated with anti-FLAG-conjugated beads, and associated HDAC1 was detected by Western blotting by using anti-HDAC1 antibodies.