Molecular mechanisms of neurotransmitter release and its

神经递质释放的分子机制及其

• 批准号: 6990672
• 负责人: Zu-hang Sheng
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6990672
• 关键词: biological signal transduction; calcium channel; calmodulin dependent protein kinase; cyclic AMP; endocytosis; exocytosis; immunocytochemistry; immunoprecipitation; nerve /myelin protein; neural plasticity; neural transmission; neurons; neurotransmitter transport; phosphorylation; polymerase chain reaction; protein kinase A; protein protein interaction; protein quantitation /detection; protein structure function; second messengers; small interfering RNA; synaptic vesicles; synaptotagmin; syntaxin; tissue /cell culture; western blottings

To understand the molecular mechanisms underlying neurotransmitter release and its modulation, we are identifying proteins including Snapin, syntaphilin, and syntabulin that control the trafficking, targeting, and assembly of presynaptic release machinery at nerve terminals. We are further analyzing the functional roles of these proteins using molecular, biochemical, cell biological, and electrophysiological analysis (collaborating effort with other labs). The continued application of these approaches, in combination with a greater focus on cellular siRNA knockdown and genetic knockout studies, will allow us to better understand the regulatory pathways that govern the synaptic vesicle exocytosis and regulate synaptic strength. Syntabulin is one of our major focuses during the fiscal year 2004. The process of neurotransmitter release involves a series of protein-protein interactions between the membranes of synaptic vesicles and presynaptic terminals. Syntaxin-1 is a key component of the membrane fusion machinery at the presynaptic plasma membrane. Presynaptic proteins involved in synaptic vesicle exocytosis are synthesized in the soma of neurons, incorporate into transport cargo vesicles, and undergo proper trafficking to the synaptic terminal. However, little is known regarding the mechanisms by which cargo organelles containing vesicle release machinery physically associate with their microtubule-based transport motors. In an effort to characterize syntaphilin isoforms, we have identified a gene encoding a novel syntaxin-binding protein named syntabulin. Syntabulin attaches syntaxin-containing vesicles to microtubules and migrates with syntaxin within the processes of hippocampal neurons. Knockdown of syntabulin expression with targeted siRNA or interference of the syntabulin-syntaxin interaction inhibit attachment of syntaxin-cargo vesicles to microtubules and reduce syntaxin-1 distribution in the neuronal processes. Furthermore, molecular motor protein kinesin I KHC binds to syntabulin and associates with syntabulin-linked syntaxin vesicles in vivo. These findings suggest that syntabulin acts as a linker molecule that attaches syntaxin-cargo vesicles to motor kinesin I, enabling the transport of syntaxin-1 to neuronal processes. Our findings provide new clues to the cellular mechanisms that are likely to underlie the specific trafficking of synaptic cargoes.

为了了解神经递质释放的分子机制及其调节，我们正在鉴定包括Snapin，syntaphilin和syntabulin在内的蛋白质，这些蛋白质控制着神经终端处的贩运，靶向和组装的运输，靶向和组装。我们正在使用分子，生化，细胞生物学和电生理分析（与其他实验室的协作工作）进一步分析这些蛋白质的功能作用。这些方法的持续应用，结合更多地关注细胞siRNA敲低和遗传基因敲除研究，将使我们能够更好地理解控制突触小囊泡外胞菌病并调节突触强度的调节途径。 征素蛋白是2004财政年度的主要重点之一。神经递质释放的过程涉及突触囊泡和突触前末端的膜之间的一系列蛋白质 - 蛋白质相互作用。 Syntaxin-1是突触前质膜上膜融合机械的关键组成部分。参与突触小囊泡胞吐作用的突触前蛋白在神经元的躯体中合成，纳入运输货物囊泡，并经过适当的运输到突触末端。然而，关于含有囊泡释放机械的货物细胞器与基于微管的传输电动机的机制知之甚少。为了表征杂素同工型，我们已经确定了一个编码一种新型义传毒素结合蛋白的基因，称为syntabulin。征素蛋白将含义含量的囊泡连接到微管上，并在海马神经元的过程中用义话迁移。用靶向siRNA敲低征素表达或征素 - 羟基相互作用的干扰抑制了语法素 - 碳糖囊泡在微管上的附着，并减少神经元过程中的Syntaxin-1分布。此外，分子运动蛋白驱动蛋白I KHC与征素蛋白结合，并在体内与征素连接的语法囊泡结合。这些发现表明，征素蛋白充当连接的分子，该分子将语法素 - 碳酸盐囊泡连接到运动动力蛋白I，从而实现了Synttaxin-1向神经元过程的运输。我们的发现为细胞机制提供了新的线索，这些方法可能是突触货物的特定贩运基础的基础。