FIG. 3.

Etk associates with STAT3 in vivo via the PH domain of Etk. (A) Schematic representation of the Etk protein and its mutants. Various structural domains are also labeled. RP, the two direct repeats in the Etk sequence (48); PK, protein kinase domain. (B) Association of STAT3 with Etk or its deletion mutants. 293 cells were transfected with STAT3 and/or T7-tagged wild-type or mutant Etk as indicated. Cell lysates were immunoprecipitated with anti-T7 antibody, followed by Western blotting with anti-STAT3 antibody to detect Etk-bound STAT3 (top) or with anti-Etk antibody to demonstrate the expression of Etk and its mutants (middle). Similar cell lysates were subjected to Western blotting with anti-STAT3 antibody to detect the expression of STAT3 (bottom).