FIG. 6.

14-3-3β binding inhibits β₁PixGEF activity. (A) Anti-Myc immunoprecipitates were treated with vehicle (○ and ⋄) or PKA catalytic subunit (⧫, •, and ×) and then incubated with GDP-loaded Rac1 and γ-³⁵S-GTP in the presence (⋄, •, and ×) or absence (• and ⧫) of 200 nM of GST-14-3-3β. (B) Cells were transfected with Myc-β₁Pix, and the cell lysates were immunoprecipitated using anti-Myc antibody. After incubation with the catalytic PKA subunit, immunoprecipitates were incubated with GDP-loaded Rac1 and γ-³⁵S-GTP in the presence of different concentrations of His-14-3-3β or negative control His-14-3-3β(K51E, R58E, R62E). GDP/GTP exchange assays were carried out for 30 min. Experiments shown here are representative of three independent experiments carried out in duplicate.