PORE TOPOLOGY OF THE N-METHYL-D-ASPARTATE RECEPTOR

本文所述研究的目的是阐明 配体门控离子通道家族的分子拓扑学 (i.e.,谷氨酸受体）介导最快的突触传递 在CNS。尽管人们普遍接受最新的 谷氨酸受体拓扑结构，该区域侧翼的建议发夹 成孔区的结构（即，M2：还没有 成功地被证明驻留在细胞的同一侧 膜中的功能蛋白质。使用N-甲基-N D-天冬氨酸（NMDA）受体作为原型，假设存在 将测试M2发夹结构。在两侧区域， 特定标记（例如，磷酸化或蛋白酶敏感位点）将 通过诱变引入并在单通道贴片期间进行测试 夹紧记录，以便在功能中定位它们的方向 受体。对重要的NMDA进行这样的研究的好处是 受体亚单位很多。受体被认为是介导 神经元变性的各种病理条件， 中风到癫痫此外，有人提议， 在长期记忆形成中的重要作用。最后，一种合理的药物 对这一潜在靶点进行药理学操作的设计将 需要了解可从蛋白质中获得的氨基酸残基。 细胞外间隙

The objective of the research described here is elucidation of the molecular topology of the family of ligand-gated ion channels (i.e.,glutamate receptors) which mediate most fast synaptic transmission in the CNS. Despite widespread acceptance of the newest model of glutamate receptor topology, the regions flanking the proposed hairpin structure for the pore-forming region (i.e., M2) have not yet successfully been demonstrated to reside on the same side of the cell membrane in a functional protein. Using the NR1 subunit of the N-methyl- D-aspartate (NMDA) receptor as a prototype, the hypothesized existence of the M2 hairpin structure will be tested. In the flanking regions, specific markers (e.g., phosphorylation or protease-sensitive sites) will be introduced via mutagenesis and tested during single channel patch clamp records in order to localize their orientation in functional receptors. The benefits of performing such a study on the essential NMDA receptor subunit are numerous. The receptor is believed to mediate neuronal degeneration in a variety of pathologic conditions ranging from stroke to epilepsy. Additionally, it has been proposed to play a fundamental role in long-term memory formation. Finally, a rational drug design for pharmacologic manipulation of this potential target would require knowledge of the amino acid residues accessible from the extracellular space.