FIGURE 6.

Interaction between JAK3 and Fes kinases. A, Fes activity in non-transformed (MCF10A and COS-7) and transformed (MDA-MB-231, MCF-7, AML-3D10 and dHL-60) cells following silencing of JAK3. B, Fes activity following transfection with either Fes or JAK3 plasmid DNA. (The Fes plasmid was used as a positive control for Fes kinase activity.) C, JAK3 activity of MCF10A and MDA-MB-231 cells following transfection with either Fes or JAK3 plasmid DNA. (The JAK3 plasmid was used as a positive control for JAK3 kinase activity.) D, JAK3 and Fes form a protein-protein complex as detected using co-immunoprecipitation. Immunoprecipitation (I.P.) was performed with rabbit anti-JAK3 IgG antibodies bound to protein G-agarose beads, and after SDS-PAGE, the resulting Western blots (W.B.) were probed with rabbit anti-Fes IgG antibodies (top panel). Negative controls using IgG antibody for co-immunoprecipitations are included for each cell line (second panel from top). Fes was detected at the native molecular mass of ∼95 kDa (second panel from bottom).