title: Interaction of NAP-22 with brain glutamic acid decarboxylase (GAD).
abstract: NAP-22 (also called BASP1 or CAP-23) is a neuron-enriched protein localized mainly in the synaptic vesicles and the synaptic plasma membrane. Biochemically, it is recovered in the lipid raft fraction. In order to understand the physiological function of the neuronal lipid raft, NAP-22 binding proteins were screened with a pull-down assay. Glutamic acid decarboxylase (GAD) was detected through LC-MS/MS, and Western blotting using a specific antibody confirmed the result. Two isoforms of GAD, GAD65 and GAD67, were expressed in bacteria as GST-fusion forms and the interaction with NAP-22 was confirmed in vitro. Partial co-localization of NAP-22 with GAD65 and GAD67 was also observed in cultured neurons. The binding showed no effect on the enzymatic activity of GAD65 and GAD67. These results hence suggest that NAP-22 could participate in the transport of GAD65 and GAD67 to the presynaptic termini and their retention on the synaptic vesicles as an anchoring protein.
authors: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan. smaekawa@kobe-u.ac.jp
authors: Shohei
authors: S
authors: Maekawa
authors: Yuumi
authors: Y
authors: Kobayashi
authors: Sin-Ichi
authors: S
authors: Odagaki
authors: Midori
authors: M
authors: Makino
authors: Haruko
authors: H
authors: Kumanogoh
authors: Shun
authors: S
authors: Nakamura
authors: Mitsuhiro
authors: M
authors: Morita
authors: Fumio
authors: F
authors: Hayashi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005968:Glutamate Decarboxylase / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D051381:Rats
chemical_list: D002148:Calmodulin-Binding Proteins; D003598:Cytoskeletal Proteins; D007527:Isoenzymes; D009419:Nerve Tissue Proteins; C066853:Basp1 protein, rat; D005968:Glutamate Decarboxylase