Nerve Growth Factor Signaling

神经生长因子信号传导

• 批准号: 7014044
• 负责人: MARIE W WOOTEN
• 金额: $ 32.97万
• 依托单位: AUBURN UNIVERSITY AT AUBURN
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 2008-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7014044
• 关键词: binding sites; biological signal transduction; cell cycle proteins; ceramides; electrophysiology; enzyme activity; enzyme mechanism; genetically modified animals; growth factor receptors; guanine nucleotide binding protein; immunocytochemistry; immunoprecipitation; isozymes; laboratory mouse; neurogenesis; neurotrophic factors; phosphorylation; protein kinase C; protein localization; protein protein interaction; protein tyrosine kinase; protooncogene; second messengers; site directed mutagenesis; ubiquitin

Despite being intensively studied, the mechanism whereby the neurotrophin receptor, TrkA, traffics intracellularly is not yet completely understood. Recent data collected in my laboratory indicate that the NGF receptors, p75 and TrkA, cooperatively signal through a novel bridge protein, p62. At its carboxy-terminus p62 possesses a ubiquitin associating domain (DBA) and is capable of binding K63-polyubiquitinated substrates. The amino-terminus of p62 directs its interaction with the proteasome. In addition, p62 serves as a scaffold to recruit TRAF6, an E3-ubiquitin ligase. I hypothesize that p62 binds K63-polyubiquitinated proteins through its UBA domain and shuttles these proteins to the proteasome for degradation. Preliminary findings reveal that TrkA and tau are both TRAF6/K63-polyubiquitinated substrates that interact with p62's UBA domain. Thus, I hypothesize that the neurotrophin signaling and inclusion formation pathway are regulated at the biochemical level by a common protein, p62. The specific aims for this project period are to test the hypotheses that: 1) p62 serves as an adaptor for TRAFS-ubiquitination of TrkA, thereby regulating receptor trafficking; and, 2) p62 serves to coordinately regulate TrkA trafficking and the inclusion formation pathway in brain. We possess an isogenic p62 knockout mouse and propose to undertake comprehensive characterization of these mice to include: anatomical, behavioral, biochemical, and physiological studies. I hypothesize that as a consequence of p62's absence, K63-poIyubiquitinated proteins such as, TrkA and tau, will progressively accumulate in brain of the p62 knockout mice leading to formation of inclusions along with physiological and behavioral correlates. A number of cutting-edge biochemical, cellular and molecular techniques will be employed in the context of these studies. These findings will fill significant gaps in our understanding of neurotrophin signaling and provide important information required to understand how p62 functions at the cellular/biochemical level. Collectively, information gained from this study will enhance understanding of the role that disturbances in the ubiquitin proteasome pathway plays as a contributing factor to neurodegeneration. Altogether, these efforts will accelerate development and testing of therapeutics to disrupt aggregate formation and treat human neurodegenerative disease(s).

尽管经过深入研究，但尚未完全了解神经营养蛋白受体TRKA的机制。在我的实验室中收集的最新数据表明，NGF受体P75和TRKA通过新型的桥蛋白P62发出协同信号。在其羧基末端，p62具有泛素关联结构域（DBA），并且能够结合K63-聚素化的底物。 p62的氨基末端指导其与蛋白酶体的相互作用。此外，p62是招募traf6的支架，这是一种E3-泛素连接酶。我假设p62通过其UBA结构域结合K63-聚泛素化的蛋白质，并将这些蛋白质穿梭到蛋白酶体中以降解。初步发现表明，TRKA和TAU都是与p62的UBA域相互作用的TRAF6/K63-聚泛素化的底物。因此，我假设神经营养蛋白信号传导和包含的形成途径在生化水平上通过常见蛋白p62调节。该项目时期的具体目的是检验以下假设：1）p62是TRKA TRAFS-泛素化的适配器，从而调节受体贩运； 2）P62可以协调调节TRKA运输和大脑中的纳入形成途径。我们拥有一只等生p62敲除小鼠，并建议对这些小鼠进行全面表征，其中包括：解剖，行为，生化和生理研究。我假设，由于p62的缺失，K63 p-Poiyupipipientation的蛋白（例如TRKA和TAU）将逐渐积聚在p62敲除小鼠的大脑中，从而形成夹杂物以及生理和行为相关性。在这些研究的背景下，将采用许多尖端的生化，细胞和分子技术。这些发现将填补我们对神经营养蛋白信号传导的理解，并提供了解p62在细胞/生化水平上的功能所需的重要信息。从这项研究中获得的信息总体而言，将增强对泛素蛋白酶体途径中干扰的作用的理解，这是神经变性的促成因素。总的来说，这些努力将加速和测试治疗剂，以破坏总体形成并治疗人类神经退行性疾病。