Mechanisms of Glutamate Receptor Synaptic Clustering

描述(由申请人提供)：该奖项的目标是支持Dane Chetkovich博士作为一名独立的内科科学家的职业生涯。这位候选人将继续他对谷氨酸受体(Glur)突触聚集的研究，这是他在加州大学旧金山分校David Bredt博士的指导下发起的一个项目，并在他自己的西北大学实验室继续进行。谷氨酸受体是负责大脑中大部分兴奋性交流的蛋白质。神经元通讯效率的改变是通过改变突触上GluR的数量或性质来调节的，是学习和记忆的基础。此外，GluRs与许多疾病的病理生理学有关，包括阿尔茨海默病。Stargazin是一种谷氨酸结合蛋白，在癫痫和共济失调的观星小鼠中发生突变。在观星老鼠的大脑中，Glur是正常产生的，但它不针对突触。切特科维奇博士之前的工作表明，星氮素将GluR运送到突触依赖于星氮素的几个部分，这些部分与其他蛋白质相互作用，包括一种被称为nPIST的蛋白质(与TC10特异相互作用的神经元蛋白质)。这种结合发生在Stargazin的一个区域，该区域对于适当的Glur靶向突触至关重要。为了进一步探索nPIST在GluR靶向突触中的作用，Chetkovich博士将使用细胞生物学、生化和电生理学方法来验证这样一种假设，即nPIST通过将nPIST/stargazin/Glur受体复合体递送到突触支架蛋白来陪同GluR受体靶向突触，并且nPIST结构域的磷酸化调节这一过程。该项目的具体目的是：1)了解nPISTPDZ结构域相互作用在GluR突触聚集中的作用；2)探讨nPIST磷酸化在GluR突触聚集中的作用；3)评估Stargazin家族成员与nPIST和GluR亚单位在GluR突触聚集中的相互作用。这些实验将加深对GluR靶向突触的基本机制的理解，并将为异常GluR靶向导致神经疾病的机制提供新的见解。这些研究有望带来新的发现，为开发治疗阿尔茨海默病等致残神经疾病的治疗方法确定新的靶点。除了该项目在对人类疾病重要的领域取得科学进步的目标外，K02还将允许切特科维奇博士有受保护和有组织的研究时间继续他的工作，指导他的受训者，并在他发展科学事业的过程中与科学同事互动。西北大学为这些研究提供了一个出色的环境，神经病学系已经承诺为切特科维奇博士作为一名独立的内科科学家取得成功提供资源。预计切特科维奇博士在该奖项和西北大学充满活力和支持的环境的推动下取得的进步，将使R01机制和其他资金的竞争取得成功，以进一步支持他的职业发展和科学努力。

DESCRIPTION (provided by applicant): The goal of this Award is to support Dr. Dane Chetkovich in his career as an independent physician-scientist. The candidate will continue his studies on glutamate receptor (GluR) synaptic clustering, a project he initiated under the mentorship of Dr. David Bredt at the University of California, San Francisco and has continued in his own laboratory at Northwestern University. GluRs are proteins responsible for most of the excitatory communication in the brain. Changes in neuronal communication efficiency are mediated by changing the number or properties of GluRs at synapses, and underlie aspects of learning and memory. Additionally, GluRs are implicated in the pathophysiology of many diseases, including Alzheimer's disease. Stargazin is a GluR-binding protein that is mutated in the epileptic and ataxic stargazer mice. In the stargazer mouse brain, GluR is made normally, but it does not target to synapses. Dr. Chetkovich's prior work demonstrated that stargazin delivery of GluRs to synapses is dependent on several parts of stargazin that interact with other proteins, including a protein known as nPIST (neuronal Protein interacting Specifically with TC10). This binding occurs at a region of stargazin that is critical for proper GluR targeting to the synapse. To further explore the role of nPIST in GluR targeting to the synapse, Dr. Chetkovich will use cellular biological, biochemical and electrophysiological approaches to test the hypothesis that nPIST chaperones the targeting of GluR receptors to the synapse by delivering the nPIST/stargazin/GluR receptor complex to synaptic scaffolding proteins, and that phosphorylation of the nPIST domain regulates this process. The Specific Aims of the proposed project are: 1) To understand the role of nPISTPDZ domain interactions in GluR synaptic clustering; 2) To explore the role of nPIST phosphorylation in GluR synaptic clustering; and 3) To evaluate stargazin family member interactions with nPIST and GluR subunits in GluR synaptic clustering. These experiments will enhance understanding of the basic mechanism of GluR targeting to synapses, and should provide new insight into mechanisms by which abnormal GluR targeting contributes to neurological disease. These studies will hopefully lead to discoveries that identify novel targets for the development of treatments to fight disabling neurological diseases such as Alzheimer's disease. In addition to the project's goal of scientific progress in an area important to human disease, the K02 will allow Dr. Chetkovich protected and structured research time to continue his work at the bench and mentor his trainees and interact with scientific colleagues as he develops his scientific career. Northwestern University offers an outstanding environment for these studies, and the Department of Neurology has committed the resources for Dr. Chetkovich to succeed as an independent physician-scientist. It is anticipated that Dr. Chetkovich's progress, fostered by this award and the dynamic and supportive environment of Northwestern University, will enable successful competition for R01 mechanism and other funding to further sustain his career development and scientific efforts.