Figure 2.

Analysis of the PIAS1–Stat1 interaction in vitro. (A) The COOH terminus of PIAS1 is sufficient to interact with Stat1. GST or GST-Stat1 immobilized on glutathione Sepharose beads was mixed with various ³⁵S-labeled PIAS1 peptides as indicated. Bound proteins were analyzed on SDS/PAGE followed by autoradiography. GST and GST-Stat1 on beads were visualized by Coomassie blue staining (Lower). (B) The COOH terminus of PIAS1 interacts with the NH₂ terminus of Stat1 in vitro. Same as A except GST-Stat1(1–448) was used in GST pulldown assays.