Figure 2.

Endogenous Gro and endogenous Rpd3 form a complex in vivo. (A) Immunoprecipitation of embryonic (lanes 1–4) and S2 cell (lanes 5–8) nuclear extracts. (Lanes 1,5) Unfractionated nuclear extracts; (lanes 2,6) immunoprecipitates obtained with nonimmune serum; (lanes 3,7) immunoprecipitates obtained with anti-Gro antibody; (lanes 4,8) immunoprecipitates obtained with anti-Flag antibody. Proteins were analyzed by SDS-PAGE and immunoblotting with anti-Gro (top) or anti-Rpd3 (bottom) antibodies. (B) In vitro histone deacetylase assays of immunoprecipitates from embryonic nuclear extract. Samples assayed are those shown in lanes 1-4 of A. In addition, purified baculovirus-expressed Rpd3 was assayed as a positive control. Each sample was assayed in the presence (+) or absence (−) of the histone deacetylase inhibitor TSA (150 nm).