Mechanism of functional modulation of glutamate receptors by their auxiliary subunits

谷氨酸受体辅助亚基的功能调节机制

基本信息

批准号：
10176871
负责人：
Terunaga Nakagawa
金额：
$ 38.3万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10176871
关键词：
AMPA Receptors Affect Alanine Alzheimer&apos s Disease Architecture Binding Brain Cognition Complex Conflict (Psychology)Corpus striatum structure Cryoelectron Microscopy Detergents Drug Targeting Electrophysiology (science)Environment Excision Family Future Glutamate Receptor Glutamates Goals Heterogeneity Hippocampus (Brain)Human Ion Channel Ion Channel Gating Kinetics Knowledge Learning Ligands Limbic Encephalitis Lipid Bilayers Lipids Location Mediating Memory Mental disorders Missense Mutation Modeling Molecular Molecular Conformation Mutate Mutation Neurotransmitters Outcome Outcome Study Play Production Regulation Resolution Role Seizures Side Signal Transduction Specimen Stroke Structure Synapses Synaptic Transmission Synaptic plasticity System Testing Therapeutic Transmembrane Domain autism spectrum disorder density desensitization design experience experimental study member nanodisk nervous system disorder neurotransmission novel therapeutics receptor binding receptor function reconstitution reduce symptoms stoichiometry structured data trafficking

项目摘要

The AMPA type ionotropic glutamate receptors (AMPARs), a ligand gated ion channel activated by the neuro- transmitter glutamate, mediate the majority of excitatory neurotransmission in the brain. The signals trans- duced by these complexes are critical for synaptic plasticity, learning and memory. AMPAR auxiliary subunits regulate trafficking and gating modulation of AMPARs. In this proposal we will investigate the mechanism of AMPAR regulation by their auxiliary subunits. The two major AMPAR auxiliary subunits, in the hippocampus, cortex, and striatum, are TARPs and cornichons (CNIHs). The TARPs are extensively studied and therapeutic compounds to alleviate seizure are already available to target γ-8 TARP, a hippocampus enriched TARP. On the other hand, our understanding on CNIHs is limited. Within the CNIH family, CNIH2/3 is known to function as AMPAR auxiliary subunits. In humans, the N-terminus of CNIH2 that forms the interaction interface with AMPAR is intolerant to missense mutations, indicating an essential role of CNIH2-AMPAR interaction in hu- mans. Our hypothesis is that CNIHs play fundamental roles in regulating AMPAR gating during synaptic transmission and plasticity. To further establish this hypothesis, we will study the functional mechanism of complexes made of GluA2 subunit of AMPAR and CNIH3 as a model. Our lab has recently solved the cryo-EM structure of GluA2/CNIH3 complex in GluA2:CNIH3=4:4 stoichiometry at high resolution. In Aim 1 we hypothe- size that the GluA2/CNIH3 complex could exists in other stoichiometry, and propose to reveal the architecture of complex in GluA2:CNIH3=4:2 stoichiometry using cryo-EM. CNIH1 is currently not categorized as AMPAR auxiliary subunit. However the cryo-EM structure of the GluA2/CNIH3 complex tells us that CNIH1 possess AMPAR binding motif that is present in CNIH2/3. The cryo-EM structure also revealed the presence of lipids surrounding the complex. We hypothesize that these lipids may play important functional roles in AMPAR gat- ing modulation. In Aim2 we will test roles of CNIH1 and lipids in gating modulation of AMPAR. Finally, we hy- pothesize that revealing the allosteric gating modulation mechanism of CNIH3 would require obtaining snap- shots of lipid embedded GluA2/CNIH3 complex in channel closed, open, and desensitized states. In Aim 3, we propose to solve high resolution cryo-EM structures of GluA2/CNIH3 complex embedded in a lipid bilayer mi- metic environment, and compare them in different functional states. The role of auxiliary subunits in tuning ion channel gating kinetics is predicted to have significant impact on circuit dynamics. In summary, the outcomes of this study are expected to advance our mechanistic understanding of AMPAR function and assist developing new therapeutic compounds that can alleviate dysregulation of AMPARs seen in neurological and psychiatric disorders, such as Alzheimer's disease, stroke, autism, Rasmussen's and limbic encephalitis, and seizure.

AMPA型离子型谷氨酸受体（AMPARS），一种由神经 - 激活的配体门控离子通道发射机谷氨酸，介导大脑中的大多数兴奋性神经传递。信号trand- 这些复合物对突触可塑性，学习和记忆至关重要。 AMPAR辅助亚基调节AMPAR的贩运和门控调节。在此提案中，我们将调查 AMPAR通过其辅助亚基进行调节。海马的两个主要AMPAR辅助亚基，皮质和纹状体是防水布和玉米片（CNIHS）。篷布是广泛的研究和治疗。减轻癫痫发作的化合物已经可用于靶标γ-8 TARP，这是一种富含海马的防潮。在另一方面，我们对CNIHS的理解是有限的。在CNIH家族中，已知CNIH2/3起作用作为AMPAR辅助亚基。在人类中，形成与与 AMPAR对错义突变不宽容，表明CNIH2-AMPAR相互作用在HU- 芒。我们的假设是，CNIHS在突触期间调节AMPAR门控中起着基本作用传输和可塑性。为了进一步建立这一假设，我们将研究由AMPAR和CNIH3的GLUA2亚基制成的复合物作为模型。我们的实验室最近解决了Cryo-EM GLUA2中GluA2/CNIH3复合物的结构：CNIH3 = 4：4高分辨率的化学计量。在目标1中，我们假设 GLUA2/CNIH3复合物可能存在于其他化学计量的大小，并提出揭示体系结构的建议 Glua2中的复合物：CNIH3 = 4：2使用冷冻EM化学计量。 CNIH1目前尚未归类为AMPAR 辅助亚基。但是GLUA2/CNIH3复合物的冷冻EM结构告诉我们CNIH1位置 CNIH2/3中存在的AMPAR结合基序。冷冻EM结构还揭示了脂质的存在围绕着综合体。我们假设这些脂质可能在AMPAR GAT-中起重要的功能作用调制。在AIM2中，我们将测试CNIH1和脂质在AMPAR的门控调制中的作用。最后，我们 - 揭示CNIH3的变构门控调制机制将需要获得snap- 在通道封闭，开放和脱敏状态下，脂质嵌入的GLUA2/CNIH3复合物的镜头。在AIM 3中，我们解决嵌入脂质双层中的GluA2/CNIH3复合物的高分辨率冷冻EM结构的提议元环境，并在不同的功能状态进行比较。辅助亚基在调谐中的作用通道门控动力学预计将对电路动力学产生重大影响。总而言之预计这项研究将提高我们对AMPAR功能的机械理解并协助开发可以减轻神经和精神病学中AMPAR失调的新治疗化合物疾病，例如阿尔茨海默氏病，中风，自闭症，拉斯穆森（Rasmussen）和边缘性脑炎以及癫痫发作。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

GSG1L-containing AMPA receptor complexes are defined by their spatiotemporal expression, native interactome and allosteric sites.

DOI：
10.1038/s41467-023-42517-7
发表时间：
2023-10-26
期刊：
NATURE COMMUNICATIONS
影响因子：
16.6
作者：
Perozzo, Amanda M.;Schwenk, Jochen;Kamalova, Aichurok;Nakagawa, Terunaga;Fakler, Bernd;Bowie, Derek
通讯作者：
Bowie, Derek

Modulatory mechanisms of TARP γ8-selective AMPA receptor therapeutics.

DOI：
10.1038/s41467-023-37259-5
发表时间：
2023-03-25
期刊：
NATURE COMMUNICATIONS
影响因子：
16.6
作者：
Zhang, Danyang;Lape, Remigijus;Shaikh, Saher A.;Kohegyi, Bianka K.;Watson, Jake F.;Cais, Ondrej;Nakagawa, Terunaga;Greger, Ingo H.
通讯作者：
Greger, Ingo H.