Specificity of calcium channels in neuronal signaling

钙通道在神经信号传导中的特异性

• 批准号: 6540191
• 负责人: JI-FANG ZHANG
• 金额: $ 39.06万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6540191
• 关键词: binding proteins; biological signal transduction; calcium channel; dynein ATPase; hippocampus; immunocytochemistry; neurons; protein kinase C; protein localization; protein protein interaction; tissue /cell culture; yeast two hybrid system

DESCRIPTION (provided by applicant): Voltage dependent Ca2+ channels are transmembrane proteins, which allow Ca2+ entry upon activation. In addition to their electrogenic role, Ca2+ channels provide a pivotal link between membrane depolarization and a wide range of cellular functions. Ca2+ action is often local and close to its source of entrance. Ca2+ action is also very specific. Ca2+ influx through different types of Ca2+ channels can activate distinct cellular signaling cascades. For instance, compared to L-type Ca2+ channels, Ca2+ influx through NMDA receptors activates a distinct signaling pathway for regulation of gene expression. With its abundant and varied intracellular targets, how is Ca2+ able to achieve specificity and activate only a subset those targets in neurons? The long-term goal is to understand the role and molecular mechanisms of Ca2+ channels in neuronal signaling. Specifically, in this proposal, we will test the hypothesis that specific interactions exist between Ca2+ channels and certain other intracellular proteins. Such interactions are of functional significance. Specific aims include isolation and characterization of proteins, which interact with Ca2+ channels. Using yeast two-hybrid system, we have screened a brain cDNA library with the C-termini of three different Ca2+ channel alpha1-subunits as baits. 177 clones have been sequenced. Three clones have been selected for functional studies. They include tctex-1, a light chain of the dynein complex; clones L157 and N397, two distinct forms of PKC binding proteins. Experiments are in progress to address the functional significance of the interactions between Ca2+ channels and those clones in the following aspects: (1) differential distribution of different types of Ca2+ channels in neurons (tctex-1); and (2) modulation of channel activities by PKC and/or initiation of the PKC signaling cascade (L157 & N397). Preliminary data indicate that the interaction between Ca2+ channels and these clones we selected indeed bears the functional significance as we had hypothesized.

描述（由申请人提供）：依赖电压CA2+通道为 跨膜蛋白，可在激活时进入Ca2+进入。此外 它们的电源作用Ca2+通道在膜之间提供了关键的联系 去极化和广泛的细胞功能。 CA2+动作通常是 本地，靠近其入口来源。 CA2+动作也非常具体。 CA2+通过不同类型的Ca2+通道涌入可以激活不同的 细胞信号传导级联。例如，与L型Ca2+通道相比 Ca2+通过NMDA受体涌入可激活一个独特的信号通路 基因表达的调节。其丰富的细胞内 目标，CA2+如何能够达到特异性并仅激活子集 那些神经元中的靶标？ 长期目标是了解CA2+的作用和分子机制 神经元信号传导中的通道。具体来说，在此提案中，我们将测试 Ca2+通道和 某些其他细胞内蛋白质。这样的相互作用具有功能性 意义。具体目的包括蛋白质的隔离和表征， 与Ca2+通道相互作用。 使用酵母双杂交系统，我们已经筛选了一个脑cDNA库 三种不同的Ca2+通道α1-亚基作为诱饵的C末端。 177个克隆 已经测序了。已经选择了三个克隆进行功能研究。 它们包括TCTEX-1，这是Dynein复合物的轻型链；克隆L157和 N397，两种不同形式的PKC结合蛋白。实验正在进行中 解决Ca2+之间相互作用的功能意义 频道和这些克隆在以下方面：（1）差异 神经元中不同类型的Ca2+通道的分布（TCTEX-1）； （2） 通过PKC调制通道活动和/或PKC信号的启动 级联（L157和N397）。初步数据表明 我们选择的CA2+通道和这些克隆确实具有功能 正如我们假设的那样意义。