Pleckstrin-2 shows affinity for phosphoinositides with D3 phosphates. GST fusion proteins were made in the pEGX-2TK vector, which allowed the direct (γ-³²P) ATP labeling by PKA of the fusion proteins in vitro. Results were viewed by standard autoradiograph techniques and quantified via the Image Quant Program. Relative affinity was calculated by quantitating bound ³²P divided by specific activity of the radioactive probe. Shown is the mean ± SEM from 3 independent experiments.