14-3-3ζ is a Stat3-interacting protein.

<p>(A) Immunoprecipitation assays of 14-3-3ζ and Stat3 proteins were carried out in U266 cells as described in Materials and Method section. No band of Stat3 was observed in the IgG negative control (Ctr). (B) Interaction of Stat3 with 14-3-3 isoforms. (C) Schematic illustration of Stat3 domains and their truncations. ND: N-terminal domain, CC: coiled-coil domain, DBD: DNA binding domain, LD: linker domain, SH2: SH2 domain and CT: C-terminal. (D) Identification of the Stat3 domains interacting with 14-3-3ζ. Myc-Stat3 domain truncation mutants were transfected with HA-14-3-3ζ in U266 cells. An empty vector was used as a control. Anti-HA immunoprecipitates were analyzed by Western blot with antibodies to Myc (upper panel) or HA (middle panel). The expression of Myc-Stat3 is shown in the bottom panel. (E) Stat3 C-terminal mutants binding to 14-3-3ζ. Experiments were performed in triplicate and representative data are shown.