Gfi1B interacts with Triad1. (A) His-Triad1 was isolated from baculovirus-infected Hi-5 cells using His-Select beads. Proteins bound to beads were detected with SDS-PAGE followed by coomassie staining. A clear His-Triad1 band is visible, while no proteins can be detected when beads were incubated with uninfected Hi-5 cells. (B) In vitro–translated and 35S-labeled Gfi1B was incubated with empty beads or His-Triad1–loaded beads. Full-length Gfi1B and the 6–zinc finger domain interacted with Triad1, but not the Δzinc finger domain. (C) GFP-Triad1 or GFP was cotransfected with Flag-Gfi1B in COS cells. α-GFP–immunoprecipitated proteins (α-GFP clones 7.1 and 13.1; Roche Diagnostics) were immunoblotted and stained with a different α-GFP antibody (sc-8334; Santa Cruz Biotechnology) to check the immunopreciptiation. α-Flag staining showed that Gfi1B interacts with GFP-Triad1 but not with GFP alone. Whole-cell extract (wce) was blotted with α-Flag antibody to show equal Gfi1B expression.
