FIG. 7.

PTEN targets TFIIIB. (A) PTEN does not alter the protein levels of the TFIIIB components. (Left) LN18 cells were transfected with PTEN siRNA or mmRNA. (Right) PTEN-inducible U87 cells were treated with DOX (24 h). Total protein was isolated, and immunoblot analysis was performed using antibodies against the proteins indicated. (B) PTEN disrupts the association between TBP and Brf1. LN18 cells were transfected with PTEN siRNA or mmRNA, and total protein was isolated. Coimmunoprecipitation assays (IP) and immunoblot analyses (IB) were performed using antibodies against TBP or Brf1. The change in association is calculated based on values from cells transfected with mmRNA. (C) Rapamycin induces dissociation between TBP and Brf1. U87 cells were treated with 100 nM rapamycin (3 h), and total protein was isolated. Coimmunoprecipitation assays and immunoblot analyses were performed as described above (B). The change in association is calculated based on values from cells treated with dimethyl sulfoxide. Representative autoradiographs are shown. Graphs represent determinations from at least three biologically independent samples (means ± SE).