FAK and PYK2 interact with SAP90/PSD-95-Associated Protein-3.

Focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2) are two related non-receptor tyrosine kinases highly expressed in brain. Although they are both involved in synaptic plasticity, little is known about their specific neuronal partners. Using a yeast two-hybrid screen and GST pull-down assays we show that SAPAP3 (SAP90/PSD-95-Associated Protein-3) interacts with FAK (residues 676-840) and PYK2. The three proteins partly co-distribute in the same sucrose gradient fractions as the post-synaptic density protein PSD-95 and Src. Our results suggest that SAPAP3 is an anchoring protein for FAK and PYK2 in post-synaptic densities and may contribute to the synaptic function of these tyrosine kinases.