Interaction of NAP-22 with brain glutamic acid decarboxylase (GAD)
Interaction of NAP-22 with brain glutamic acid decarboxylase (GAD)
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NAP-22 与脑谷氨酸脱羧酶 (GAD) 的相互作用
DOI：
10.1016/j.neulet.2013.01.030
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发表时间：
2013
期刊：
影响因子：
2.5
通讯作者：
F.
中科院分区：
文献类型：
--
作者：
Maekawa;M.;Kobayashi;Y.;Odagaki;S.;Makino;M.;Kumanogoh;H.;Nakamura;S.;Morita;M.;Hayashi;F.
NAP-22（也称为BASP 1或CAP-23）是主要定位于突触囊泡和突触质膜中的神经元富集蛋白。在生物化学上，它在脂筏部分中被回收。为了了解神经元脂筏的生理功能，NAP-22结合蛋白用下拉分析筛选。通过LC-MS/MS检测谷氨酸脱羧酶（GAD），并使用特异性抗体进行Western印迹证实了该结果。GAD的两种亚型GAD 65和GAD 67在细菌中以GST融合形式表达，并在体外证实了与NAP-22的相互作用。在培养的神经元中也观察到NAP-22与GAD 65和GAD 67的部分共定位。结合显示对GAD 65和GAD 67的酶活性没有影响。因此，这些结果表明，NAP-22可以参与GAD 65和GAD 67的运输到突触前末梢和它们的保留在突触囊泡作为锚定蛋白。
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.