Mechanisms controlling AMPA receptor subunit composition

控制 AMPA 受体亚基组成的机制

• 批准号: 8849997
• 负责人: STEVEN J TAVALIN
• 金额: $ 26.25万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8849997
• 关键词: A kinase anchoring protein; AMPA Receptors; Biochemical; Biological Models; Calmodulin; Cells; Complex; Cyclic AMP-Dependent Protein Kinases; DLG1 gene; Data; Disease; Drug abuse; Endocytosis; Fright; Glutamate Receptor; Glutamates; Hippocampus (Brain); Image; Kinetics; Learning; Light; Link; Mediating; Memory; Mental disorders; Methods; Molecular; Neuraxis; Neurodegenerative Disorders; Neurons; Neurotransmitters; Pain; Permeability; Phospholipids; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Play; Polyamines; Property; Protein Kinase; Protein Kinase C; Proteins; Relative (related person); Rodent; Role; Signal Transduction; Site; Stroke; Surface; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Testing; Trauma; Work; base; calcineurin phosphatase; citrate carrier; neuron development; neurotransmission; novel; receptor; response; scaffold; transmission process; treatment strategy

DESCRIPTION (provided by applicant): Glutamate is the major excitatory neurotransmitter in the central nervous system. Activation of ionotropic glutamate receptors contributes to synaptic plasticity, neuronal development, neuropathophysiological insults, neurodegenerative diseases, drug abuse, and psychiatric disorders. Among the glutamate receptors, AMPA receptors (AMPARs) are predominantly responsible for fast excitatory neurotransmission. AMPARs tend to be preferentially assembled in heteromeric complexes composed of GluA1 and GluA2 subunits. GluA2 subunits act in a dominant fashion to control several receptor properties including Ca2+ permeability, single channel conductance, receptor kinetics, and sensitivity to intracellular polyamines. Thus, alterations in subunit composition have a dramatic impact on the quality and strength of synaptic transmission. Although the majority of AMPARs are thought to be heteromers of GluA1 and GluA2, accumulating evidence has highlighted the ability for synaptic AMPAR composition to shift in favor of GluA1 homomers. This shift can occur in response to both physiological and pathophysiological forms of synaptic plasticity including fear, stroke, pain, and drug abuse. Thus, it is critical to understand mechanisms that contribute to these changes in AMPAR composition. By targeting protein kinase C (PKC) to GluA2, protein interacting with C-kinase 1 (PICK1) is thought to stabilize PKC phosphorylation of GluR2 which serves to signal endocytosis of GluA2-containing AMPARs. Thus, PICK1 and PKC are thought to be central for alterations in AMPAR composition. Recently, we demonstrated that A- kinase anchoring protein 79 kDa (AKAP79; AKAP150 in rodents) targets PKC to GluA1 AMPARs to enhance the phosphorylation and the activity of these receptors. Based on preliminary data, we propose that AKAP79- anchored PKC regulates AMPAR subunit composition by favoring homomeric GluA1 receptors. Moreover, we propose that both PKC-affiliated scaffolds work in conjunction with each other to ultimately determine the AMPAR subunit composition. In order to test this hypothesis, we will use biochemical, electrophysiological, molecular methods, and a novel imaging based approach to understand the: 1) Whether AKAP79 favors homomeric GluA1 receptors via GluA1 regulatory sites using a simplified heterologous system. 2) Whether PICK1 and PKC sites on GluA2 contributes to AKAP79-dependent shifts in AMPAR composition and conversely whether GluA1 regulatory sites contribute to PICK-dependent alterations in AMPAR composition. 3) Whether AKAP150-anchored PKC is central towards generating homomeric GluA1 responses in neurons under a number of conditions linked to synaptic plasticity. Collectively, these studies will shed light on the contributions of PKC-affiliated scaffolds towards determining AMPAR subunit composition and delineate the relative importance of regulatory sites on GluA1 and GluA2 AMPAR subunits which are a critical factor for both heath and disease.

描述（申请人提供）：谷氨酸是中枢神经系统中主要的兴奋性神经递质。嗜离子性谷氨酸受体的激活有助于突触可塑性、神经元发育、神经病理生理损伤、神经退行性疾病、药物滥用和精神疾病。在谷氨酸受体中，AMPA受体（ampar）主要负责快速兴奋性神经传递。ampar倾向于优先组装在由GluA1和GluA2亚基组成的异质复合物中。GluA2亚基以主导方式控制多种受体特性，包括Ca2+通透性、单通道电导、受体动力学和对细胞内多胺的敏感性。因此，亚基组成的改变对突触传递的质量和强度有巨大的影响。尽管大多数AMPAR被认为是GluA1和GluA2的异构体，但越来越多的证据强调了突触AMPAR组成向GluA1同构体转移的能力。这种转变可以发生在生理和病理生理形式的突触可塑性的反应中，包括恐惧、中风、疼痛和药物滥用。因此，了解导致AMPAR组成变化的机制是至关重要的。通过将蛋白激酶C （PKC）靶向GluA2，与C-激酶1 （PICK1）相互作用的蛋白被认为可以稳定PKC对GluR2的磷酸化，从而信号化含GluA2的AMPARs的内吞作用。因此，PICK1和PKC被认为是AMPAR组成改变的核心。最近，我们证明了A-激酶锚定蛋白79 kDa （AKAP79；啮齿类动物中的AKAP150）将PKC靶向到GluA1 AMPARs上，以增强这些受体的磷酸化和活性。基于初步数据，我们提出AKAP79锚定的PKC通过支持同源GluA1受体来调节AMPAR亚基组成。此外，我们提出两个pkc附属支架相互结合，最终确定AMPAR亚基组成。为了验证这一假设，我们将使用生化、电生理、分子方法和一种新的基于成像的方法来了解：1)使用简化的异源系统，AKAP79是否通过GluA1调控位点倾向于同源GluA1受体。2) GluA2上的PICK1和PKC位点是否导致了AMPAR组成中akap79依赖性的改变，反之，GluA1调控位点是否导致了AMPAR组成中pick依赖性的改变。3)在与突触可塑性相关的许多条件下，akap150锚定的PKC是否在神经元中产生同源GluA1反应中起核心作用。总的来说，这些研究将阐明pkc附属支架在确定AMPAR亚基组成方面的贡献，并描述GluA1和GluA2 AMPAR亚基上的调控位点的相对重要性，这是健康和疾病的关键因素。

项目成果

Control of protein synthesis and memory by GluN3A-NMDA receptors through inhibition of GIT1/mTORC1 assembly.

• DOI: 10.7554/elife.71575
• 发表时间: 2021-11-17
• 期刊: eLife
• 影响因子: 7.7
• 作者: Conde-Dusman MJ;Dey PN;Elía-Zudaire Ó;Rabaneda LG;García-Lira C;Grand T;Briz V;Velasco ER;Andero R;Niñerola S;Barco A;Paoletti P;Wesseling JF;Gardoni F;Tavalin SJ;Perez-Otaño I
• 通讯作者: Perez-Otaño I