REGULATION OF NMDA RECEPTOR CLUSTERING BY EPH KINASES

EPH 激酶对 NMDA 受体聚集的调节

• 批准号: 6166482
• 负责人: MUSTAFA SAHIN
• 金额: $ 12.56万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6166482
• 关键词: NMDA receptors; developmental neurobiology; laboratory rat; ligands; membrane activity; mixed tissue /cell culture; neuronal transport; phosphorylation; protein localization; protein protein interaction; protein structure function; protein tyrosine kinase; receptor binding; receptor expression; synaptogenesis

The goal of this project is to characterize the signaling pathways that regulate synaptogenesis in the developing brain. Previous studies have demonstrated that synapses differentiate in a series of steps, one of which is the clustering of postsynaptic neurotransmitter receptors. In the neuromuscular junction, clustering of the cholinergic receptors is induced by a proteoglycan (agrin), which activates a receptor tyrosine kinase (MuSK). In the central nervous system, it is not clear what regulates the clustering of postsynaptic receptors such as the NMDA receptors at excitatory synapses. Preliminary data from the Sponsor's laboratory indicate that activation of Eph receptor tyrosine kinases on cultured hippocampal neurons induces the clustering of a NMDA receptor subunit, NR1. Furthermore, Eph receptor ligands (ephrins) induce a biochemical interaction between the Eph and NMDA receptors. This study will examine the protein-protein interactions that mediate ephrin-induced NMDA receptor clustering through three specific aims. First, we will identify the domains of Eph and NR1 receptors that are critical for ephrin-induced receptor clustering. Then, we will investigate the role of tyrosine phosphorylation on the clustering of NMDA receptors by Eph tyrosine kinases. Finally, the cellular mechanisms of NMDA receptor clustering will be examined through two sets of experiments. We will present the ephrin ligands on the cell membrane and determine their effect on the NMDA receptors on neighboring neurons. Mechanisms of synapse formation are of particular interest to pediatric neurologists because aberrant synapse formation is likely to underlie common developmental disorders such as mental retardation and epilepsy. Through intensive training in basic science under the supervision of Dr. Michael Greenberg and clinical practice in pediatric neurology at the Children's Hospital in Boston, the candidate expects to become a physician- scientist equipped with the molecular and cellular tools to study neuronal dysgenesis in children.

该项目的目标是表征发育中大脑中调节突触发生的信号通路。先前的研究表明，突触通过一系列步骤进行分化，其中之一是突触后神经递质受体的聚集。 在神经肌肉接头中，胆碱能受体的聚集是由蛋白聚糖（集聚蛋白）诱导的，蛋白聚糖可激活受体酪氨酸激酶 (MuSK)。 在中枢神经系统中，尚不清楚是什么调节突触后受体的聚集，例如兴奋性突触处的 NMDA 受体。 申办者实验室的初步数据表明，培养的海马神经元上 Eph 受体酪氨酸激酶的激活会诱导 NMDA 受体亚基 NR1 的聚集。 此外，Eph 受体配体（肝配蛋白）诱导 Eph 和 NMDA 受体之间的生化相互作用。 这项研究将通过三个特定目标来研究介导肝配蛋白诱导的 NMDA 受体聚集的蛋白质-蛋白质相互作用。 首先，我们将确定对肝配蛋白诱导的受体聚类至关重要的 Eph 和 NR1 受体的结构域。 然后，我们将研究酪氨酸磷酸化对 Eph 酪氨酸激酶 NMDA 受体聚集的作用。 最后，我们将通过两组实验来研究 NMDA 受体聚集的细胞机制。 我们将在细胞膜上呈现肝配蛋白配体，并确定它们对邻近神经元 NMDA 受体的影响。儿科神经学家对突触形成的机制特别感兴趣，因为异常的突触形成可能是智力低下和癫痫等常见发育障碍的基础。 通过在迈克尔·格林伯格博士的监督下进行基础科学强化培训以及在波士顿儿童医院进行儿科神经病学临床实践，候选人期望成为一名拥有分子和细胞工具来研究儿童神经元发育不全的医师科学家。