Alpha7 Nicotinic Receptor: Structures and Coupling with Intracellular Proteins

神经型烟碱型乙酰胆碱受体(NAChRs)属于五聚体配基门控离子超家族 介导快速神经传递的通道(PLGIC)，是各种神经疾病的治疗靶点 疾病和紊乱。然而，目前还没有一个单一的高分辨率结构被确定 包含胞外(ECD)、跨膜(TMD)和胞内(ICD)的全长nAChRs 域名。X射线结晶学和低温电子显微镜都不适用于柔性ICD的结构解析。线条 大量证据表明，nAChRs与突触相关的细胞内蛋白之间存在直接相互作用 可塑性和细胞信号通路，但由于缺乏分子细节而被揭示。 ICD的高分辨率结构。在这里，我们建议确定α7nAChR的结构，它是 大脑中最丰富的nAChR亚型。我们已经成功地培育出具有功能的全身人 α7nAChR和α7nAChR的TMDICD以及实质性的初步结构和功能结果， 为开展α7nAChR的结构研究奠定了坚实的基础。使用核磁 共振谱(核磁共振)和电子顺磁共振(EPR)，我们将确定 ICD的原子分辨结构。ICD结构将与现有的 ECD和TMD，以及我们新收集的结构约束，以生成全长结构 静息状态下的α7nAChR。我们将阐明α7nAChR脱敏的构象变化， 已知它在突触控制动作电位传递中起着重要作用。最后，我们会 确定α7nAChR与细胞内支架蛋白的结合方式对分布的影响 α7nAChR表达于细胞表面。生成的结构将为开发治疗方法提供有用的信息 α7nAChR相关疾病的治疗策略。

Neuronal nicotinic acetylcholine receptors (nAChRs) belong to the superfamily of pentameric ligand-gated ion channels (pLGICs) that mediate fast neurotransmission and are therapeutic targets for various neurological diseases and disorders. However, no single high-resolution structure has yet been determined for any full-length nAChRs that contains the extracellular (ECD), transmembrane (TMD), and intracellular (ICD) domains. Neither X-ray crystallography nor cryo-EM is suitable for resolving structures of the flexible ICD. Lines of evidence suggest direct interactions between nAChRs and intracellular proteins implicated in synaptic plasticity and cell signaling pathways, but few molecular details have been revealed due to the lack of high-resolution structures of the ICD. Here, we propose to determine structures of α7nAChR, which is one of the most abundant nAChR subtypes in the brain. We have successfully produced functional human full-length α7nAChR and the TMD+ICD of α7nAChR along with substantial preliminary structural and functional results, which built a solid foundation for carrying out structural investigations of α7nAChR. Using nuclear magnetic resonance spectroscopy (NMR) and electron paramagnetic resonance (EPR), we will determine atomic-resolution structures of the ICD. The ICD structures will be integrated with available structures of the ECD and TMD, as well as with our newly collected structure restraints to generate structures for full-length α7nAChR in the resting state. We will elucidate conformational changes underlying α7nAChR desensitization, which is known to play a significant role in the synaptic control of action-potential transmission. Finally, we will determine binding modes of α7nAChR networked with intracellular scaffold proteins that affect the distribution of α7nAChR on the cell surface. The generated structures will provide useful information for developing treatment strategies for diseases related to α7nAChR.