FIGURE 5.

Serine 834 phosphorylation governs SSH1L binding to 14-3-3 and phosphatase activity. A, effect of serine 834 phosphorylation in the binding to 14-3-3. HEK cells were cotransfected with 14-3-3-HIS and either SSH1L-S834D-CFP or SSH1L-S834A-CFP. After 24 h, His-tagged proteins were pulled down using dynabeads and the amount of SSH1L was analyzed using an antibody against CFP. Bars represent mean ± S.E. average of four independent experiments. B, SSH1L-S834A acts as a constitutively active enzyme. VSMCs were transfected with GFP vector, wt SSH1L, or SSH1L-S834A by electroporation. Cells were then treated with vehicle or PDGF (10 ng/ml for 15 min). Bars represent mean ± S.E. average from three independent experiments.