FIG. 8.

PTEN expression disrupts the association of TBP with RNA Pol I-specific TAFs. (A) Immunoprecipitation of TBP-TAF_I110 and TBP-TAF_I63 complexes. Protein lysates were prepared from PTEN-inducible U87 cells treated with 1 μg/ml DOX as designated. Immunoprecipitation assays were carried out using anti-TBP antibodies and 400 μg of protein lysate as described in Materials and Methods. Bound proteins were then subjected to immunoblot analysis, and antibodies against TBP, TAF_I 110, or TAF_I 63 were used to detect the proteins. The values shown are means ± SEM from three independent determinations where the amounts of TBP, TAF_I110, and TAF_I63 coimmunoprecipitated with TBP were calculated relative to control noninduced cells. (B) Immunoprecipitation of TAF_I110-TBP complexes. Protein lysates were prepared from PTEN-inducible U87 cells as designated. Immunoprecipitation assays were carried out using 400 μg of protein lysate by using antibodies against TAF_I110. Bound proteins were then subjected to immunoblot analysis, and antibodies were used to detect TAF_I110 and TBP. The values are the means ± SEM from four independent determinations where the amounts of TAF_I110 and TBP coimmunoprecipitated with TAF_I110 were calculated relative to control noninduced cells.