Regulation of tomosyn-SNARE complex assembly in neurosecretion

神经分泌中 tomosyn-SNARE 复合体组装的调节

• 批准号: 7145476
• 负责人: EDWARD L STUENKEL
• 金额: $ 36.93万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-20 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7145476
• 关键词: balance; cell membrane; chromaffin cells; exocytosis; granule; neurotransmitter transport; proteins

DESCRIPTION (provided by applicant): The assembly of SNARE proteins into a ternary core complex is essential for neurotransmitter release. Precise regulation of SNARE complex assembly ultimately determines the site and dynamics of the exocytotic event. Our objective is to understand the mechanisms that regulate temporal and spatial assembly of these SNARE complexes. Tomosyn is a protein that is critical in setting the level effusion- competent SNARE complexes. Its regulatory action has been proposed to be primarily mediated by its interaction with the Q-SNARE syntaxinl A, which results in the formation of non-fusogenic SNARE complexes. The goal of the research proposed is to provide an understanding of the molecular mechanisms and signal transduction pathways governing the assembly/disassembly of tomosyn-SNARE complexes in the regulated release of neurotransmitter. Our general hypothesis is that tomosyn-SNARE complex formation is promoted by Rho-GTPase signaling pathways and antagonized by protein kinase A-dependent pathways, with the balance of activation of these pathways fine-tuning the level of fusion-competent SNARE complexes. Aim 1 will test the hypothesis that the formation of tomosyn-SNARE complexes is under dynamic control by secretory agonists to regulate secretion. In addition, we will identify N-terminal tomosyn domains important for this regulation, and quantity effects of endogenous tomosyn on granule priming and exocytosis. Aim 2 will test the hypothesis that the level of tomosyn-SNARE complexes and their functional effects on the exocytotic pathway are finely regulated by a balance between the activation state of Rho, to promote tomosyn-SNARE complex assembly, and PKA, to antagonize tomosyn-SNARE complex assembly. Aim 3 will define the spatial properties of tomosyn-SNARE complexes on the plasma membrane and determine if RhoA and PKA mediate spatially delimited effects on the assembly and disassembly of these complexes. Experiments will be performed using a combination of biochemical, optical and electrophysiological approaches on adrenal chromaffin cells, a highly characterized cell model for neurotransmitter release. Understanding the regulation of neurotransmitter release is essential to understanding the function of the nervous system and fundamental to development of therapeutic treatments in the many psychiatric and neurological conditions typified by an imbalance of particular neurotransmitters.

描述（由申请人提供）：将军团蛋白组装到三元核心复合物中对于神经递质释放至关重要。 SNARE复合物组装的精确调节最终决定了胞吐事件的位置和动力学。我们的目标是了解调节这些圈套复合物的时间和空间组装的机制。 Tomosyn是一种蛋白质，对于设定水平积液 - 胜任的圈圈复合物至关重要。它的调节作用已被认为主要是由其与Q-Snare语法A的相互作用介导的，从而导致形成非菌基因的SNARE复合物。提出的研究的目的是提供对分子机制和信号转导途径的理解，这些途径是在神经递质的调节释放中，tomosyn-s-nare复合物的组装/拆卸。我们的总体假设是，tomosyn-s-Nare复合物的形成是由Rho-GTPase信号通路促进的，并由蛋白激酶A依赖性途径拮抗，这些途径的激活平衡微调了融合融合竞争力的snare复合物的水平。 AIM 1将检验以下假设：tomosyn-snare复合物的形成受分泌激动剂的动态控制以调节分泌。此外，我们将确定对这种调节重要的N末端tomosyn结构域，以及内源性质体对颗粒启动和胞吐作用的数量影响。 AIM 2将检验以下假设：tomosyn-Snare复合物的水平及其对胞外途径的功能作用受到Rho激活状态之间的平衡，以促进tomosyn-snare复合体组装和PKA的平衡来对其进行平衡，以拮抗Tomosyn-Snare Snare Complecters组装。 AIM 3将定义Tomosyn-Snare复合物在质膜上的空间特性，并确定RhoA和PKA是否介导了对这些复合物的组装和拆卸的空间界定作用。实验将使用肾上腺染色体细胞的生化，光学和电生理方法的组合，这是神经递质释放的高度表征的细胞模型。了解神经递质释放的调节对于理解神经系统的功能以及在许多精神病和神经系统状况中的发展功能至关重要，这是特定神经递质失衡的代表。