PICK1 Interacts with and Regulates PKC Phosphorylation of mGLUR7

• Published in: The Journal of neuroscience Vol. 20; no. 19; pp. 7252 - 7257
• Main Authors: Dev, Kumlesh K, Nakajima, Yoshiaki, Kitano, Jun, Braithwaite, Steven P, Henley, Jeremy M, Nakanishi, Shigetada
• Format: Journal Article
• Language: English
• Published: United States Soc Neuroscience 01-10-2000; Society for Neuroscience
• Subjects: Animals; Brain - metabolism; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cells, Cultured; COS Cells; Cytoskeletal Proteins; Glutathione Transferase - genetics; Hippocampus - cytology; Hippocampus - metabolism; Isoenzymes - metabolism; Mutagenesis, Site-Directed; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Phosphorylation; PICK1 protein; Precipitin Tests; Protein Binding - genetics; Protein Isoforms - metabolism; Protein Kinase C - metabolism; Protein Kinase C-alpha; Protein Structure, Tertiary; Rats; Receptors, Metabotropic Glutamate - genetics; Receptors, Metabotropic Glutamate - metabolism; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Transfection; Two-Hybrid System Techniques
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/jneurosci.20-19-07252.2000

The G-protein-coupled metabotropic glutamate receptor subtype 7a (mGluR7a) is a member of group III metabotropic glutamate receptors that plays an important role as a presynaptic receptor in regulating transmitter release at glutamatergic synapses. Here we report that the protein interacting with C-kinase (PICK1) binds to the C terminus (ct) of mGluR7a. In the yeast two-hybrid system, the extreme ct of mGluR7a was shown to interact with the PSD-95/Discs large/ZO-1 (PDZ) domain of PICK1. Pull-down assays indicated that PICK1 was retained by a glutathione S-transferase fusion of ct-mGluR7a. Furthermore, recombinant and native PICK1/mGluR7a complexes were coimmunoprecipitated from COS-7 cells and rat brain tissue, respectively. Confocal microscopy showed that both PICK1 and mGluR7a displayed synaptic colocalization in cultured hippocampal neurons. PICK1 has previously been shown to bind protein kinase C alpha-subunit (PKCalpha), and mGluR7a is known to be phosphorylated by PKC. We show a relationship between these three proteins using recombinant PICK1, mGluR7, and PKCalpha, where they were co-immunoprecipitated as a complex from COS-7 cells. In addition, PICK1 caused a reduction in PKCalpha-evoked phosphorylation of mGluR7a in in vitro phosphorylation assays. These results suggest a role for PICK1 in modulating PKCalpha-evoked phosphorylation of mGluR7a.