INVOLVEMENT OF RAP AND RAPGAP IN NMDA RECEPTOR SIGNALING

RAP 和 RAPGAP 参与 NMDA 受体信号转导

• 批准号: 6472236
• 负责人: Daniel T Pak
• 金额: $ 4.38万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6472236
• 关键词: NMDA receptors; biological signal transduction; confocal scanning microscopy; green fluorescent proteins; guanine nucleotide binding protein; guanosinetriphosphatase activating protein; guanosinetriphosphatases; immediate early protein; immunocytochemistry; laboratory rat; mitogen activated protein kinase; neural growth associated protein; phosphorylation; protein protein interaction; protooncogene; synapses; tissue /cell culture; transcription factor

The N-methyl-D-aspartate receptor (NMDAR) has been extensively studied due to its critical role in activity-dependent synaptic plasticity and excitotoxicity. Defining the signaling cascades regulated by the NMDAR is essential for a mechanistic understanding of NMDAR function, but the intracellular signals initiated by NMDARs are not well characterized. Our laboratory has undertaken a systematic analysis of the proteins associated with the cytoplasmic tails of NMDARs with the rationale that such proteins would be ideally positioned to transduce calcium influx through the NMDAR channel to downstream signaling pathways. The multidomain protein PSD-95 appears to be an organizing center for these transducing elements, binding to NMDARs as well as to signaling molecules such as two GTPase activating proteins (GAPs). One of these, SynGAP, is a recently described Ras-specific GAP; the other, SpanGAP, is a novel GAP likely to regulate Rap small GTPases. This proposal will focus on the potential role of SpanGAP and Rap in NMDAR signaling, examining the relative contribution of this pathway (compared with the Ras pathway) in the NMDAR signaling cascade. Dominant negative mutants and antisense strategies will be employed to dissect specific transduction mechanisms in cultured primary neurons. Effects will be analyzed by using a variety of transcriptional reporters as well as phospho-specific antibodies against MAP kinases and CREB. The results of this study may shed light on novel mechanisms contributing to NMDAR-mediated synaptic plasticity and excitotoxicity.

N-甲基-D-天冬氨酸受体（NMDAR）由于其在活动依赖性突触可塑性和兴奋性毒性中的关键作用而被广泛研究。 定义由NMDAR调节的信号级联对于NMDAR功能的机制理解是必不可少的，但是由NMDAR启动的细胞内信号没有很好地表征。 我们的实验室已经对与NMDAR的胞质尾相关的蛋白质进行了系统分析，其基本原理是这些蛋白质将理想地定位于阻止钙通过NMDAR通道流入下游信号传导途径。 多结构域蛋白PSD-95似乎是这些转导元件的组织中心，与NMDAR以及信号分子如两个GTdR活化蛋白（GAP）结合。 其中之一，SynGAP，是最近描述的Ras特异性GAP;另一个，SpanGAP，是一种可能调节Rap小GTP酶的新型GAP。 该提案将重点关注SpanGAP和Rap在NMDAR信号传导中的潜在作用，检查该途径（与Ras途径相比）在NMDAR信号传导级联中的相对贡献。 显性负突变体和反义策略将被用来解剖特定的转导机制，在培养的原代神经元。将通过使用各种转录报告基因以及针对MAP激酶和CREB的磷酸化特异性抗体来分析效应。 本研究的结果可能有助于NMDAR介导的突触可塑性和兴奋性毒性的新机制。