The Role of Calcyon in Synaptic Integration

Calcyon 在突触整合中的作用

• 批准号: 6320696
• 负责人: CLARE M BERGSON
• 金额: $ 25.11万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6320696
• 关键词: autoradiography; biological signal transduction; calcium indicator; calcium ion; cell line; confocal scanning microscopy; dopamine receptor; immunocytochemistry; immunoprecipitation; ion transport; membrane proteins; neural transmission; phosphorylation; protein protein interaction; protein structure function; receptor coupling; synapses; yeast two hybrid system

DESCRIPTION (provided by applicant): Obtaining a precise understanding of the mechanism(s) by which endogenous neuromodulators such as dopamine (DA) regulate glutamergic excitatory transmission could lead to better for patients afflicted with epilepsy, Parkinson's Disease, schizophrenia, and drug addiction. Activation of the D1 dopamine receptor subtype, in particular, modulates glutamate-induced neuronal excitability in frontal cortex, hippocampus and neostriatum. Little is known about molecular mechanism(s) by which D1 receptor signaling modulates excitatory transmission. We recently identified a single transmembrane protein designated Calcyon which interacts with D1 DA receptors and localizes to vesicles in dendritic spines. Via interaction with Calcyon, D1 receptors stimulate release of Ca++ from internal stores (Ca++i) in an activity-dependent manner in heterologous expression system. A similar activity-dependent, D1 receptor agonist stimulated response is detectable by Fura-2 Ca++ imaging of primary cultures of cortical and hippocampal neurons. Our overarching hypothesis is that Calcyon enhances D1 receptor signaling through Gq/11 by serving as a link connecting D1 receptors to IP3 regulated Ca++ stores. We will determine how D1 DA receptor signaling through Gq/11 is primed, and how Calcyon enhances D1 receptor-mediated IP3 signaling. Using Ca++ imaging and peptides to block the D1 receptor:Calcyon interaction, we will determine if Calcyon is required for D1 agonist stimulated Ca++i release in dendritic spines. We propose to identify other GPCRs and accessory proteins that interact with Calcyon by yeast two-hybrid and phage display screens. We will determine how these proteins are involved in regulating release of Ca++ from vesicular stores. The results of this research should provide insight into clinical strategies to selectively boost or dampen D1 receptor mediated neuromodulation of excitatory transmission.

描述(由申请者提供)：准确了解 多巴胺等内源性神经调节剂的调节机制(S) 谷氨酰胺能兴奋性传递可以改善患者的病情 患有癫痫、帕金森氏症、精神分裂症和毒瘾。 特别是D1型多巴胺受体亚型的激活，调节 谷氨酸诱导的额叶皮质、海马神经元兴奋性 新纹状体。目前对D1R的分子机制(S)知之甚少 信号调节兴奋性传递。我们最近发现了一支 与D1DA受体相互作用的跨膜蛋白 并定位于树突棘中的小泡。通过与Calcyon的交互，d1 受体刺激血管内钙释放(Ca++i) 异源表达系统中的活性依赖方式。一种类似的 依赖活性的d1受体激动剂刺激的反应可通过 大脑皮层和海马神经元原代培养的Fura-2钙离子显像。 我们的主要假设是，Calcyon增强了D1受体信号 通过GQ/11作为连接D1R和IP3调节的纽带 CA++商店。我们将确定D1DA受体是如何通过GQ/11传递信号的 启动，以及Calcyon如何增强D1受体介导的IP3信号。使用Ca++ 成像和多肽阻断D1受体：钙离子相互作用，我们将 确定D1激动剂刺激的心肌细胞内钙离子释放是否需要钙通道蛋白 树枝状刺。我们建议鉴定其他GPCRs和辅助蛋白 通过酵母双杂交和噬菌体显示屏与Calcyon相互作用。我们 将确定这些蛋白质如何参与调节钙离子的释放 从水泡店买来的。这项研究的结果应该为我们提供关于 选择性增强或抑制D1受体介导的临床策略 兴奋性传递的神经调节。