FIG. 7.

(A) Direct interaction between STAT-3 and HNF-3. Nuclear extract from Huh-7 cells transfected with v-Src expression vector or STAT-3 synthesized in bacteria was incubated with GST (lanes 1 and 3) and GST-HNF-3 (lanes 2 and 4) bound to glutathione-Sepharose beads. STAT-3 bound to HNF-3 was extensively washed and subjected to SDS-7.5% PAGE followed by immunoblot analysis using anti-STAT-3 polyclonal antibodies. (B) In vivo interaction between STAT-3 and HNF-3. Huh-7 v-Src-transfected lysates were immunoprecipitated (IP) with anti-STAT-3 serum (lane 1) and normal human serum (NHS) (lane 2) fractionated by SDS-PAGE and electroblotted onto a PVDF membrane. The membrane was incubated with anti-HNF-3 serum followed by incubation with a secondary antibody and analyzed by ECL, a commercial detection kit.The arrow indicates the coimmunoprecipated HNF-3 in the STAT-3-HNF-3 in vivo complex.