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)：SNARE蛋白组装成一个三元核心复合体是神经递质释放所必需的。对SNARE复合体组装的精确调控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控这些陷阱复合体的时间和空间组装的机制。Tomosyn是一种蛋白质，它对设定渗出能力强的SNARE复合体的水平至关重要。它的调节作用被认为主要是通过与Q-SNARE Synaxinl A的相互作用来调节的，这导致了非融合性SNARE复合体的形成。这项研究的目的是为了了解TomosynSNARE复合体在调节神经递质释放过程中组装/分解的分子机制和信号转导途径。我们的一般假设是，TomosynSNARE复合体的形成由Rho-GTPase信号通路促进，并被依赖于蛋白激酶A的通路拮抗，这些通路的激活平衡微调融合功能SNARE复合体的水平。目的1验证一种假说，即Tomosyns-SNARE复合体的形成受到分泌激动剂的动态控制，以调节分泌。此外，我们还将确定对这种调节重要的N-末端Tomosyn结构域，以及内源性Tomosyn对颗粒启动和胞吐作用的数量效应。目的2验证一种假设，即促进Tomosyn-SNARE复合体组装的激活状态Rho和拮抗TomosynSnare复合体组装的PKA之间的平衡精细地调节TomosynSnare复合体的水平及其对胞吐途径的功能影响。目的3将确定细胞膜上TomosynSNARE复合体的空间性质，并确定RhoA和PKA是否在这些复合体的组装和拆卸中介导空间限定的效应。实验将使用生化、光学和电生理相结合的方法对肾上腺嗜铬细胞进行，肾上腺嗜铬细胞是一种高度特征化的神经递质释放细胞模型。了解神经递质释放的调节对于了解神经系统的功能是至关重要的，也是开发治疗以特定神经递质失衡为典型的许多精神和神经疾病的基础。