Interaction of brain somatostatin receptors with the PDZ domains of PSD-95.

Using peptide affinity purification, we identified an interaction between somatostatin receptors SSTR4 and SSTR1 and PDZ domains 1 and 2 of the postsynaptic proteins postsynaptic density protein of 95kDa (PSD-95) and PSD-93. The existence of the SSTR4/PSD-95 complex was verified by coimmunoprecipitation from transfected cells and solubilized brain membranes. In neurons, dendritically localized SSTR4 partially colocalizes with postsynaptic PSD-95. As functional parameters of the receptor, such as coupling to potassium channels, are not affected by the interaction with PSD-95, the association may serve to localize the receptor to postsynaptic sites.